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The Panel met at 8:00 a.m. in Salons A, B and C of the Gaithersburg Hilton, 620 Perry Parkway, Gaithersburg, Maryland, Dr. William H. Maisel, Chairman, presiding.
Call to Order................................... 3
William H. Maisel, M.D., M.P.H., Chairperson
Special Presentation............................ 8
Bram Zuckerman, M.D., Division Director, DCD
Open Public Session
Carol Tools.................................... 11
Sponsor Presentation: Abiomed, Inc.
H040006: AbioCor Implantable Replacement Heart
Dr. Robert Kung................................ 23
Questions and Answers.......................... 72
Eric Chen . . . . . . . . . . . . . . . . . . . . 90
Julie Swain . . . . . . . . . . . . . . . . . . . 99
Joanne Lindenfeld . . . . . . . . . . . . . . . 160
Thomas Ferguson . . . . . . . . . . . . . . . . 184
William H. Maisel, M.D., M.P.H. . . . . . . . . 200
Geretta Wood . . . . . . . . . . . . . . . . . . 200
8:12 a.m.
DR. MAISEL: Good morning. I'd like to call to order this meeting of the Circulatory System Devices Panel. Today's topic is discussion of a premarket notification -- that doesn't sound right -- for an HDE application for the Abiomed, Incorporated, AbioCor Implantable Replacement Heart, H040006. I'd like to have Gretta read the conflict of interest statement.
MS. WOOD: Before I read the conflict of interest statement I would just like to remind the panel and the audience that we're here to discuss a humanitarian device exemption. And the panel is here to evaluate whether or not the device exposes patients to unreasonable risk of illness or injury, and to assess the probable benefit to health, whether it outweighs the risk of injury or illness from its use, taking into account the probable risk and benefits of currently available treatments.
The following announcement addresses conflict of interest issues associated with this meeting, and is made a part of the record to preclude even the appearance of an impropriety. To determine if any conflict existed, the agency reviewed the submitted agenda, and all financial interests reported by the committee participants. The conflict of interest statutes prohibit special government employees from participating in matters that could affect their or their employers' financial interests. However, the agency has determined that participation of certain members and consultants, the need for whose services outweighs the potential conflict of interest involved is in the best interest of the government.
Therefore, a waiver has been granted for Dr. Eugene Blackstone for his employer's pending interest in the sponsor's study registry for which he will have no involvement, and has no knowledge of its funding. The waiver allows this individual to participate fully in today's deliberations. Copies of this waiver may be obtained from the agency's Freedom of Information Office, Room 12A-15 of the Parklawn Building.
We would like to note for the record that the agency took into consideration other matters regarding Dr. Clyde Yancy. This panelist reported past and current interests involving a firm at issue, but in matters that are not related to today's agenda. The agency has determined therefore that he may participate fully in the panel's deliberations.
In the event that the discussions involve any other products or firms not already on the agenda for which an FDA participant has a financial interest, the participant should excuse him- or herself from such involvement, and the exclusion will be noted for the record. With respect to all other participants, we ask in the interest of fairness that all persons making statements or presentations disclose any current or previous financial involvement with any firm whose products they may wish to comment upon.
I would also like to note for the record that Dr. Cynthia Tracy was unable to attend today's meeting. We do have a quorum of panel members present for the record.
DR. MAISEL: Thank you, Gretta. At this point I'd like to have the panel members introduce themselves. I am William Maisel, a cardiologist at Brigham and Women's Hospital. And why don't we start with Mr. Morton, please.
MR. MORTON: I'm Michael Morton. I'm the Industry Representative, and I'm a full-time employee of Medtronic, Incorporated.
DR. NELSON: Robert Nelson. I'm in pediatric critical care and bioethics at Children's Hospital, Philadelphia, and the University of Pennsylvania.
DR. BORER: I'm Jeffrey Borer. I'm a cardiologist. I work at Weill Medical College of Cornell University in New York City.
DR. WEINBERGER: I'm Judah Weinberger. I'm an interventional cardiologist at Columbia Presbyterian, New York City.
DR. KATO: Norman Kato, cardiothoracic surgery, private practice, Encino, California.
DR. VETROVEC: George Vetrovec, cardiology, Virginia Commonwealth University, Richmond.
DR. BLACKSTONE: Eugene Blackstone, Director of Clinical Research, Department of Thoracic Cardiovascular Surgery, Cleveland Clinic.
DR. PAGE: Richard Page. I've lost my voice. University of Washington in Seattle. I'm a cardiologist.
DR. YANCY: Clyde Yancy, heart failure and heart transplantation, UT Southwestern Medical Center in Dallas.
DR. FERGUSON: Tom Ferguson, cardiothoracic surgery, Washington University St. Louis.
MS. WOOD: Gretta Wood, Executive Secretary.
DR. LINDENFELD: Joanne Lindenfeld, cardiologist, University of Colorado.
DR. SOMBERG: John Somberg, Rush University, Chicago.
DR. WHITE: Chris White, cardiology, The Ochsner Clinic, New Orleans.
DR. NORMAND: Sharon-Lise Normand. I'm Professor of Health Care Policy and Biostatistics at Harvard University.
DR. KRUCOFF: Mitch Krucoff, interventional cardiologist at Duke University Medical Center, and the Director of the Cardiovascular Devices Unit at the Duke Clinical Research Institute.
MS. MOTTLE: Linda Mottle, Consumer Rep, Director of Clinical Research program, Gateway College, Phoenix.
DR. VASSILIADES: Tom Vassiliades, cardiac surgeon at Emory University in Atlanta.
DR. ZUCKERMAN: Bram Zuckerman, Director, FDA Division of Cardiovascular Devices.
DR. MAISEL: Thank you. Before we get started on this morning's topic, Dr. Zuckerman has a presentation he would like to make.
DR. ZUCKERMAN: Thank you. Actually, it's a bit of sad news, and a bit of good news. Many of you know that today is Mr. Morton's last panel meeting. He'll be rotating off the panel. Certainly I and many others on the panel have greatly enjoyed working with him. In addition to his great on-the-scenes work, he had done tremendous work behind the scenes to make sure that this panel conducts its business in a very open, transparent, objective, and scientific manner. And so we know that we'll be missing Mike.
As a token of our appreciation, the agency does have a special award and plaque to give to Mr. Morton. I'd like to briefly read from it. The letter is from Sheila Walcoff, our Associate Commissioner for External Relations, and it says, "Dear Mr. Morton, I would like to express my deepest appreciation for your efforts and guidance during your term as the Industry Representative member of the Circulatory System Devices Panel of the Medical Devices Advisory Committee. The success of this committee's work reinforces our conviction that responsible regulation of consumer products depends greatly on the participation and advice of the non-governmental health community. In recognition of your distinguished service to the Food and Drug Administration, I am pleased to present you with the enclosed plaque," and it's signed Sheila Walcoff, Esquire, Associate Commissioner for External Relations. And it's presented to Mike Morton in recognition of his outstanding service to this advisory panel.
DR. MAISEL: Thank you Dr. Zuckerman. At this point I would like to begin the Open Public Hearing portion of this meeting. Both the Food and Drug Administration and the public believe in a transparent process for information-gathering and decision-making. To ensure such transparency at the open public hearing session of the advisory committee meeting, FDA believes that it is important to understand the context of an individual's presentation. For this reason, FDA encourages you, the open public hearing speaker, at the beginning of your written or oral statement to advise the committee of any financial relationship that you may have with the sponsor, its product, and if known its direct competitors. For example, this financial information may include the sponsor's payment of your travel, lodging, or other expenses in connection with your attendance at the meeting. Likewise, FDA encourages you at the beginning of your statement to advise the committee if you do not have any such financial relationships. If you choose not to address this issue of financial relationships at the beginning of your statement, it will not preclude you from speaking.
There are several people who have asked to address the panel today, and we will start with Dr. Robert Jarvik. Is Dr. Jarvik here? How about Ms. Patty Pryor? You may step up to the podium, please. Move the microphone down. Thank you.
MS. TOOLS: I'm Carol Tools. I'm the wife of the first AbioCor recipient, Robert Tools. And I have no financial interest in Abiomed. They did pay for me to be able to come here, because I wanted to tell you how important it was for him to have that implant.
When I first met Robert he was a high school science teacher, and eventually -- he was in Chicago. And we moved away from there. We moved to Colorado and he changed occupations. But at age 50 he had a massive heart attack, with a lot of heart muscle damage which cannot be corrected. And from that time on he went downhill, so to speak. Every year he got a little bit worse, and it was -- he lived about eight and a half years before he was implemented with the AbioCor.
Now, during that time he was picked up on that IV therapy. There's three different IV drugs. Basically given to patients that are waiting for a heart transplant, except he could not have a heart transplant because he developed a number of other conditions, diabetes, etcetera. The IV therapy that he was on had some of its own problems. You know, he always had to carry around the little bags of medicine. There's batteries for the pump, and he had tubes that went directly into the vein. So if you bumped him, sometimes he would be in a lot of pain. You had to be real careful around him.
Finally, he had declined to the point where he was just -- he was nursing home quality. He was living in the recliner at home. I would get him up once a day. The doctors had said that, you know, any day now I'm going to come home from work and he's going to be dead in the chair. And he was such a vibrant person. Everybody loved him, he was very gregarious. And his kids used to come out for the summer. But then, you know, as he got worse they also got older. They were in their early twenties, and they were getting on with their own lives. And so we kind of were a little bit distant. If you've ever had anybody that's in a nursing home, or terminally ill, you'll know that sometimes their focus is totally on themselves.
So his doctor just received the letter from Jewish Hospital, and mentioned it to him. And we read the article in Newsweek. And we thought, well, maybe this would work. Maybe this would help. Because he didn't -- at this point, he didn't have any quality of life. I mean, he couldn't even walk over to the neighbor's. He was pretty much homebound, you know, stuck in his chair. And so we thought we would give it a try. He was on oxygen by that time. He had gone into renal failure earlier in the year. We had called the family in, thinking that that was the end. But he was still alive. I was amazed that he was still alive because he was -- he had lost about 100 pounds from, you know, from before the heart attack. And he was just a little skeleton of a person.
And we went up, and it was kind of a difficult trip because we had to take the mobile oxygen with. And I wasn't really adept at handling him getting in and out of the car. But we, you know, went through the process and they thought that the AbioCor would fit inside his chest. And so they went ahead and did it. Personally, I thought that there's no way a man could be able to go through open heart surgery when he is so ill and survive. But Robert wanted to do something for the medical community, being that he used to be a high school science teacher. It was just right up his alley to do something like this.
And amazingly, he lived through it, and looked better after surgery than he had in years. And every day he would improve a little bit. His vital signs would get a little bit better. We got our quality of life back. We were able to go out. He got to go see his favorite comedian. We would go out to lunch, go out to dinner, he could walk around. He had visitors. He made a lot of new friends. Bob was very gregarious, and he loved to talk. And so this was just wonderful. He had something to talk about, and he had people to talk about it with. Plus, his kids and grandkids were able to come up and see him, and his son really, really appreciated it because he only knew him as a kid. He didn't really know him as an adult, and what a strong person he was.
And he told me that when I come here, that I especially need to thank the company for inventing this device because it made such a difference in our lives. And we're making new plans. He had improved so much compared to the therapy that he was doing before. And it was less obtrusive being hooked up to the monitor. That was nothing compared to having a tube that's directly in your vein, you know, going into a little bag. And a couple of times the tube that he had when he was on the IV therapy cracked, and we had to do an emergency -- take him to the hospital. Plus, he had been in and out of hospitals for a long time. He felt better, he was able to get out, he enjoyed being the -- having an artificial heart as opposed to anything else that he had been on.
DR. MAISEL: Thank you for your comments. Could I ask you to conclude within the next minute or so?
MS. TOOLS: Oh, okay.
DR. MAISEL: Thank you.
MS. TOOLS: I also want to say some of the things that he had to give up as he was in his declining ages he was able to again do, like go fishing. That was the most important thing to him, I would say, would be able to go fishing again. And go fishing with his grandkids and his family. Thank you.
DR. MAISEL: Thank you very much for those remarks. Are there any other members of the public who wish to address the panel this morning? Please identify yourself and state your conflict of interest.
MS. PRYOR: Good morning. My name is Patty Pryor. I have no conflict of interest with Abiomed. However, I am here on their expense. I would like to say a few words, and my brother who is also here and not on the agenda would like to have just a few minutes following.
It is with great pride that we're here today to represent our father, Tom Christerson. Dad was the second AbioCor recipient. His implant was on September 13, 2001. Thus began our 17-month journey. Now there were many, many things that we shared with the media. Mom and Dad were able to celebrate their 55th wedding anniversary. Dad was able to hold his first great-grandchild, namesake Ellen Thomas. He was able to attend one last NASCAR race. Why, not only was he throwing out first pitches at Louisville Slugger Field, and leading cheers with U of L basketball, he was also reading Dr. Seuss to the local elementary children. Dad returned home to a parade in his honor, with people lining the streets of our small community. Oh, if you could just see the smile on his face that day. He was so excited, yet so very humble. He still had his same seat at the coffee shop, and he was still able to get back in the groove of visiting the local barbershop where they spin lots of tails.
Now, these are all things that we shared with the media. But I'm here today to tell you the rest of the story. Those 17 months were probably the most challenging yet most rewarding time of our life. Thank goodness the equipment was user-friendly because we certainly were no rocket scientists. It was very nice and comforting to know that there were rocket scientists just a phone call away. Now, when you're on the clock, and the clock is ticking, you learn to take each minute and appreciate every one. Dad was on the clock, and frankly, coming from this daddy's girl, each and every moment was priceless. We had moments to sit around the table in the morning, drinking coffee, reading the paper, working on the crossword puzzle together. We had moments to go out shopping, trying to find that special birthday present for Mama, who had probably already bought it anyway. We were able to enjoy dining in some of his favorite restaurants, something that he hadn't been able to do for three years because of his extremely low sodium intake diet.
We had lessons on the proper way to handle that great-grandbaby. Dad was the baby of four older sisters, so he'd had lots of practice with theirs. We had one more Thanksgiving for our official dressing-taster, who ate half the pan before it was just right. We had times to argue over the TV remote. We had moments to sit around and laugh about times past. We decorated one more Christmas tree, and we had one last annual Christmas Eve party. We had moments to sit down and make sure that there was absolutely nothing left unsaid. And sometimes we had moments to sit quietly, enjoying the presence, just enjoying the presence of one another. It doesn't get any better.
Now that is quality of life. And those moments are what this is all about today. You know, Dad always enjoyed gambling. He could never pass up a card game, and he liked to make a little bet on cards or a ball game with friends. His biggest wager was his last. Dad bet his all on the AbioCor. He was not disappointed. Thank you.
DR. MAISEL: Thank you very much. Mr. Pryor, would you like to approach?
MR. CHRISTERSON: Good morning, Ken Christerson, Tom Christerson's son. I have no conflict of interest with Abiomed, although they did pay my way to be here so I could speak to you people today. Thanks.
If any of you have older siblings, I guess you know how it is to follow them. So I would say there's not a whole lot I could say to you that wouldn't be redundant or boring. I would like to tell a story or so, and just relay something that I've got here with me. I don't know if I ever told Carol or not, but her son Carlin, we were just a few days out of surgery, sitting in the waiting room, and Carlin came in and just introduced himself, and of course Bob was doing real well. And he came in and introduced himself, and gave us all good words of encouragement. And I remembered that. I remembered that. And after Dad's surgery and he did so well, I made it known to the people at Abiomed and at Jewish Hospital that I would be glad to speak with any of the families or people considering or that have considered, mostly that have considered. I really didn't want to be a part of their decision process, but I would be a shoulder to lean on for these people. And I was so blessed and lucky to meet some of the other recipients, because I still live in Kentucky, and within a couple of hours of Louisville, so I was able to go up and meet some people that actually had the device.
And one of the families were the Grahams. And they were -- I met them just right out of surgery. I met Mr. Graham, Mrs. Graham. She was -- they were both very nice people. He was, and she still is. She's a little short, fireball of a lady. She's really nice. And after Mr. Graham's death, she sent a letter to Bob, and he shared it with me. And I asked his permission to share it with you guys. Kind of like her, short and to the point. It's actually addressed to Bob, and the first few sentences are something for him. But she said, "I know you're all upset by what happened. It was nobody's fault, just God's plan. I wish I could have kept him longer, as I sure do miss him. Maybe Don's will to live will help others in the future, and that your great work will be successful. I know it will." And it says, "Please keep in touch. Love, Bonnie." And I think that says something. I know she couldn't make the trip, but I asked Bob if I could share that with you.
There's not a whole lot else I could say. Like I said, my sister pretty much covered everything. It was a very great experience in our lives, and just proud to be here, and thank you for your consideration.
DR. MAISEL: Thank you for your comments. Is there anyone else in the audience that wishes to address the panel this morning? At this point we will close the open public hearing portion of the meeting. I would now like to invite the sponsor to make their presentation. I'd like to remind the speakers to introduce themselves, and to state their conflict of interest.
DR. KUNG: Thank you. I am Robert Kung. I'm Chief Scientific Officer of Abiomed. Before I start, I just want to introduce a few members that are with us here today. Let me get everything working on the screen.
Thank you for having the opportunity today. I want to say before I start, before I actually introduce some of the investigators that are with us today, first there are two people that I want to just mention. The founder of Abiomed, Dr. David Lederman, is in the audience. He's currently just resigned from the company, and has passed the torch on to Mr. Michael Minogue as the CEO and Chairman. I want to mention Dr. Lederman because he, when he founded Abiomed, one of his primary vision was to some day that we can get the total artificial heart into the clinic, that can help some patients, and that was one of the primary missions of Abiomed. I am glad that he's here today. He's trying to relax after many, many years of very hard work. And I thank him for being here. And I also want to encourage our new torch-carrier, Mr. Michael Minogue, which is going to bring us forward.
Okay. We are here to talk about the AbioCor, and we are here to ask for approval for an HDE. My job is to -- I've been assigned the job of giving the prepared presentation, which is actually the easier part of the job because I know that you all have a lot of incisive and probing questions that you will ask later, and those we'll address to our investigators here, Dr. Laman Gray from Jewish Hospital, one of the principal investigators, and Dr. Robert Dowling, also of Jewish Hospital. That team has done seven implants out of the 14. We have also here today Dr. Daniel Marelli who was at UCLA when one of the implants was done. He is currently at the Jefferson College of Medicine in Philadelphia. We have Dr. Reynolds Delgado from the Texas Heart Institute. He is a cardiologist, and he was involved in all the patient selection, and the post-op care of the patients at the Texas Heart Institute. There were five implants at the Texas Heart Institute. Later I'll ask them to say a little bit regarding this program.
Moving on. Why are we here today? I think we're here today because we are here -- we're here to save lives. Okay? There are a group of patients, and perhaps it's a small group of patients, that are very sick that today there are no options from the heart failure point of view. We'd like to save those patients, try to help them regain quality of life. However, in order to do that, since there are no other treatment options, AbioCor comes into play.
Now what is AbioCor? AbioCor is a fully implantable replacement heart. It is the integration of science, engineering, and medicine into a single unit that can help the patient. And we'll give you the story behind that. I'd like to start out with a little bit of the history -- it's a history of 40 years -- on the implantable artificial heart. The technology part, it is a history in development, or rather the technology has been in development for about 30 years. And finally, all of that culminates in the last five years or so where we actually did a few patients. And there were 14 patients. We're going to talk about a little bit on that. Towards the end of the talk, we will focus on some of the FDA questions to the panel, and finally end up with a summary.
So what is an HDE? I'm sure that you've been briefed on what an HDE is. The HDE is different from a full PMA application. Safety, however, is the same. The safety considerations for the device is the same for all applications. However, the biggest difference is that PMA, you have to demonstrate effectiveness. With an HDE, one has to have a suggestion there is a benefit to the patient. And this is what we are here to talk about.
I would like to just summarize up front, and then we will conclude towards the end of the talk what probable benefit is, and what safety that we have -- what kind of probable benefit we have observed, and also what are the demonstrated safety of the device. From the probable benefit point of view, we have added one and a half years of potential life to end-stage, very end-stage heart failure patients with no other options. A very important point is that we have not seen any device-related infection. And the reason for that is there is no exit site wound. A very important aspect of this particular device. And we made that decision many, many years ago, in fact decades ago, that the thing to do is to do a fully implantable device, and try to avoid a lot of the complications associated with exit sites. This particular device, there's features in there that allow it to be operating in a very quiet mode, so it doesn't cause stresses, in terms of noise and so forth, to the recipient. We believed that is a very important quality -- characteristic from the quality point of view.
Because it is a fully implantable system, patients can regain mobility. You can do showering, bathing, and not have to worry about caring for the exit site. And we have demonstrated to some large extent that dying recipients can actually return to a certain level of active life. The system has a lot of home-monitoring aspects so that the system operation can be tracked.
What kind of safety have we demonstrated? Just to start out with, the patients that we have had are the sickest of the sickest compared to any of the previous trials that have been conducted. But despite that, we have found that the operative mortality is relatively low. It is actually comparable to some established procedures. And these established procedures are obviously complex procedures. We'll come to that a little bit later.
We have -- these are mechanical devices, support devices. We obviously have seen neuro events. And with those observations, we have made design changes. We have also made anticoagulation and antiplatelet therapy refinements in order to try to reduce these neuro event rates. We have had system failures, and we have addressed those system failures. The device actually works quite well in the hospital environment, and in normal living environments, and this includes, you know, operating cars at home, restaurants, and pretty much in all diverse environments we have not found any problems. On the bench we've run the system close to about 21 months.
History. Back in 1964, the then-National Heart Institute started the Artificial Heart Program. It was a national mission. What was the mission? The mission was to reduce death, disability from heart disease through the development and use of a variety of safe, effective, reliable cardiac assist and total replacement systems.
So what are some of the objectives that were set in that particular program in 1964? Well, there were actually four of them. The first one was emergency assist systems. And Abiomed and its predecessor company, Avco, was the first ones to introduce actually the intraaortic balloon pump into clinical use. And that was in the late '60s. The next set of cardiac assist device was the temporary cardiac assist. And we, Abiomed, did introduce a bridge-to-recovery device in 1992. Many other companies have done LVADs, and the first one was introduced in 1993, and lately the CardioREST was approved for bridge-to-transplantation. The next advance was LVAD, which was the REMATCH trial. The Heartmate was approved in 2002. And finally, the final goal, or the final objective was total replacement heart, and we are here with the AbioCor seeking for HDE approval.
This is the final milestone for the implantable artificial heart. I mentioned earlier that Abiomed was founded for this particular, this as one of the important missions. It was founded 24 years ago, and the mission was to develop devices for patients so that life need not end when the heart fails.
This program received a tremendous amount of NHLBI support. The National Heart Institute later became NHLBI. And for three decades, NHLBI actually supported this type of a program to the tune of $50 million to a number of contractors. Originally there were 24 original proposals. Four teams were selected. Abiomed currently is the only company left that is pursuing and trying to reach this final objective. The Abiomed has invested quite a bit into this program. From the personnel investment point of view, amazingly, and believe it or not we've accumulated about a thousand person-years. So I am speaking today, but there are so many people behind the scenes that has contributed tremendously to this program to date.
A little bit on the technology development over the last three decades. Started in the late '60s and the early '70s. Obviously the first important issue or feature that needs to be developed was compatible blood pumps, blood valves, and that was done in the '70s. You know, what are the flow designs, and how do you make the surfaces so that you can minimize thromboembolic problems. And so that was for, you know, the early decades.
Now, the next three items, the pumping mechanism, bronchial shunt, and energy transfer are three things, or three aspects of the total artificial heart that needs to be -- the pumping mechanism, for example, has to be miniaturized so that it can be implanted inside. The bronchial shunt has to do with the fact that we all have an imbalance in the left side and the right side because of the bronchial shunt. And for a device like the artificial heart where the left side and the right side are coupled, you have to manage that difference. That difference changes sometimes over time. So there was a significant amount of effort in the '80s that we spent to develop that particular methodology. And that is important because without that you cannot do a fully implantable device, because you may end up having to use a vent to the outside and so forth.
Finally, the energy transfer. That is an extremely important one. All of these devices require a certain amount of power to run. Not a lot of power. It's equivalent to a small light bulb, you know 20 watts or so, to run the device. But, to get that power in without having exit site requires a transcutaneous energy transmission system. And we spent a significant amount of effort in that. So having combined these three features allowed us to put in a fully implantable device.
And following that, obviously there's a lot of testing and so forth to do. In 2001, we started initial human trials. And in order to do an HDE submission, the next step that we did was that this device had to get what is called a humanitarian use device. And that had to be approved by the FDA also. And we got that approval in 2003, which then led to the current submission, which was last year on this HDE submission.
Just a little bit -- all these years, with all the technology we have, trying to get to the total artificial heart, there were some spin-off useful technology that went into clinical use. And these are two of the bridge-to-recovery devices. We have saved thousands of patients. We have supported more than 7,000 patients with these devices here.
A little bit of review on the technology itself. The AbioCor consists of two major categories. There are the internal components, and then there are the external components. First I'm going to talk about the internal ones. And there's obviously communication between the internal and the external. And there are two, one of which is the TET, which we'll cover, and the other one is another radiofrequency communication to get information in and out of the system.
So the internal component, there are four internal components. We call that the thoracic unit. That's the unit that has the pumping mechanism, the blood pumps and so forth. It is really the heart of the system that replaces the diseased heart. There is an implantable controller, and that is the brain of the system because it's got the microprocessor, which is intelligent enough to take information from the thoracic unit and decides how to run the system. There are two other pieces. One is an implantable battery, which is rechargeable. And it can run without any external power for 60 minutes. This will allow the patient to be completely ambulative. And this is where you can do bathing, showering, and so forth.
There is the implanted TET coil, a very important one. That is the interconnection to the outside world. Okay? This is where power is fed in to the body. And let me start this here. Okay, these are the four components in their sort of respective anatomical positions. This is the TET. Now, what is shown here is the external component of the TET, which is one that takes power from the outside, and transfers it to the outside. Now, I actually have the real unit here, so I can pass this around. So this is implanted, and this is the one that goes from the outside. So that's one communication that's very important. That is the feature that allowed us to do all the things that I mentioned, but it is also very important to mention that there is redundancy in the power. There's the external one and the internal one. Very important.
Just briefly on the operating principle of the device. It's got the two blood pumps, left and right, and in between is the small miniaturized driver, which has a little centrifugal pump, and it is a switching valve which changes the direction of the -- this is a hydraulic system. Blood is not pumped directly, so it's a hydraulic system that pumps fluid which is enclosed by two flexible membranes, and the blood pumps are coupled to it, and then that's how you move the blood.
Okay, next we get to the outside system. And this is being passed around. In fact, this is Mr. Christerson, I just want to show that in this particular version here he's wearing the electronics in a vest, and a battery pack also put in the vest. So with that combination, fully mobile. You can fully ambulate, fully mobile. We do have a little PDA here which provides the -- mentioned earlier, there is another RF system which is much higher frequency which can communicate between the inside and the outside. And this gives you all the information that you need to know of how the system is working. You can get cardiac output, voltages inside, system voltages, currents and so forth, are all there. In addition, there's a more complete system, which is a console, that one can get remote monitoring of all the information that is available from the inside. And remote monitoring is very important because you don't have to call up the patient to get the information. So you don't have to bother the patient. You can get useful information, and it's important to monitor the devices.
Again, a little bit on the transcutaneous energy transmission. If you have cables coming out of the body, this one obviously is a case which is well healed, but this one is a case that's not well healed. And there are many, many cases of exit site problems which actually lead to a sequelae of complications. This is what it looks like for the AbioCor now. It looks like there is a lot of stuff, but there really isn't. These are little Velcro tabs just to keep it in place. And it is actually very flexible so that it's -- you know, from the comfort point of view there's no issue.
A little bit on the patient selection part. There has always been, you know, people have always asked the question, well, do we really need biventricular support. And the fact of the matter is the answer really is yes. There are patients with overt biventricular, you know, failure and not supported by LVAD. But in addition to that, for those patients, there are a large percentage of -- well, a reasonable percentage of patients that one would think that can be helped just by the LVAD, and later on developed RV failure. And that's about 30 percent of the cases. These are collated from the literature. So the frequency is about 30 percent, and we also know that a key factor that prevents bridge-to-transplant to have a successful rate that's much higher than 60 percent is the fact that 50 percent of those 40 percent that failed, that did not get the transplant, were because of right heart failure. So there's no question that there is -- that biventricular support can help some patients.
Very briefly, what the AbioCor sort of entry criteria for the patients. These are sort of pretty obvious ones. They're not transplant candidates, they're not treatable by LVAD destination therapy. We obviously in this trial was getting the sickest of the sickest patients, and based it on OMM or optimal medical management with a very low probability of survival within 30 days in biventricular failure, obviously. And we ensure that we can get a reasonable fit with the system in a patient beforehand, before any surgery is done. And that's done by a software program which reconstructs -- you're using CT scans and so forth, or MRI scans, and you can reconstruct everything inside in a three-dimensional way, take the diseased heart out, put the device in. Important things to consider or make sure is that the device does not compress the pulmonary veins, the left bronchus, and that it's got the right -- and it doesn't come out of the chest. Those are sort of the basic considerations. And you can look at that in a two-dimensional.
A summary of the condition of the patients prior to implant given here. All of these patients were in New York Heart Association Class IV. Again, not a surprise because they were the sickest of the sick. The majority of them had rhythm problems. Ischemic cardiomyopathy is obviously the larger percentage, greater than 80 percent, and the remaining were idiopathic. A large percentage of the patients had prior surgery. All of them had multiple inotropes. Again, a large percentage on IABP support, and comorbidities on pretty much all of the patients. None of the patients passed six-minute walk, not because -- the reason for that is because they were all basically ICU-bound. They couldn't -- most of them could not even walk at all.
To put everything in perspective, I know this is not a control trial, and we're not supposed to compare -- we don't have a control group either. But there is at least -- to give some indication on how sick these patients were compared to one of the gold standards, which was the REMATCH trial. What is shown here are the Kaplan-Meier curve. This one is very familiar to I think everybody. This is the Kaplan-Meier for the control group for the REMATCH. The median survival time for these patients is around five months. Now, we had a number of patients that were screened for the AbioCor, but did not get the AbioCor for a variety of reasons. Now, we followed them out to basically 60 days, and that is the standard Kaplan-Meier of the AbioCor candidates. And the median survival, by the way, is around two weeks. The median survival for those patients is two weeks.
I want to -- again, this is trying to put everything in perspective. The REMATCH trial, up to that point, had these -- we're addressing the sickest of the sick heart failure patients. And to quote Dr. Stevenson, one of the investigators of that trial, Liz Stevenson, she said that in one of the papers circulation, a high mortality rate would have been expected for this group, meaning the REMATCH group, solely on the basis of low sodium and systemic pressure. And compared to any of the previous heart failure trials on drugs or different kinds of drugs, for example, in the REMATCH, the sodium level was around 135, and it was three milliequivalents lower than the previous trials. And the systemic pressure, again, was also lower than previous trials.
Just so that we have, again, put things in sort of perspective. Not trying to make any significant comparisons. On the AbioCor candidates, the sodium level was another three milliequivalents level lower. So they are actually down at the average of 132. So they're in the hyponatremic region. And the systolic pressure happens to be the same for those two groups, the REMATCH and the AbioCor, but the diastolic pressure was lower. The diastolic pressure on the AbioCor was below 60 millimeters.
This trial are addressing patients or healthy patients with biventricular failure. So how is that assessed? Obviously from the clinical point of view it's primarily clinical history, whether it's peripheral edema, jugular vein distension, and pericentesis. A lot of things that you physicians look for in terms of assessing further biventricular failure. There are other indicators. Obviously poor hemodynamics is one of them. Right heart function, you know on echo, hepatic function, ascites, the presence of which would be indication also, and right side feeling pressure is obviously another one, or the requirement of doing extensive therapy in order to bring the right atrial pressure down.
We have also observed something very interesting in our trial, in the AbioCor patients. That is that the atrial volumes, the left and the right atrial volumes for these patients are very large. And perhaps that's not very surprising at all, because these patients were in chronic heart failure, so the failing pressures were high, and ultimately they ended up with distended left and right atrium. Why is this important? Well, it's important because failing pressure result can be managed so that you actually have situations where people are in heart failure but the pressures are low. They are hypovolemic. But that doesn't change if you have large atrial volume. That you will see in the CT scans. You will see that in the MRI scans. So that is actually a reasonable indicator of a confirmation that these patients have biventricular failure. And we saw that in these patients. Ventricular volume obviously is another way of doing it, but in the type of CT scans that we got, it was not as sensitive to -- than the atrial volume.
A little bit of the trial outcome. We had 14 patients enrolled in four centers. Twelve of the 14 were successfully supported, meaning that they went beyond the perioperative stage. Two patients were discharged to support duration, a range between 53 and 512 days. And the cumulative support time was about five patient years. We had two perioperative deaths. One is bleeding. The other one is pulmonary artery thrombosis. So, does this mean that the operative mortality is too high? The answer is -- oh, I'm sorry.
Let me just briefly just mention what the AbioCor does. It normalized obviously hemodynamics, not a surprise. What is important is that once the patient is on AbioCor, inotropes are not needed, antiarrhythmics are not needed. We have also been able to treat patients that have very high PVRs. In other words, the device itself can pump against higher PVRs, and so if the PVR is high, it can pump against it. But it knows what level to pump at. And there is no concern for right heart failure.
Now, as far as the operative mortality, we show here a comparison between the AbioCor, which is, again, the first trial, to some complex, some of the other complex standard -- I shouldn't say "standard" but complex procedures where there's a combination of mitral CABG, or mitral aortic. The perioperative survival, if you look at it from the other point of view, which is the mortality, in our case it's around 14 percent, and for these complex cases it's around 10 to 12 percent. So it's really not that different. And similarly, the 30-day survival, from the 30-day survival point of view, which is what is tracked in a lot of these procedures, the REMATCH is around 80-some percent for the survival, 30-day survival, and the heart transplantation is actually -- well it's close to 90 percent. Again, we're not that different from established and mature procedures.
Okay, well let's get back to the patients. These patients all started out ICU-bound, and some of them did recover. And plotted over here are the kind of activities that we think are sort of the steps towards recovery. And to us, you know, we don't think much about sitting and walking, but for these patients it's very important. You know, those are the steps. By the way, this is the number of patients that have achieved those kinds of activities. You know, 11 patients here. This is seven here. And within the hospital, you know, just visiting within the hospital some of them in wheelchair. And finally, ones that actually had achieved out-of-hospital excursions. There were four patients that achieved that. In the parentheses here are the average time that these activities were achieved.
I just want to show you one video here on a patient, a 51-year-old idiopathic cardiomyopathy, high PVR, irreversible, with use of Natrecor. And he's doing exercise rehabilitation at 30 days. This patient actually lived for 290 or so days.
What is some of the significant record of clinical performance that we have demonstrated? They are summarized over here. We have had no device-related infection. We have had no thermo-related issues regarding the TET because it does transfer power. We haven't seen any device-related hemolysis. Again, nothing surprising there. Neurological complications, yes we have seen, and five of the 14 patients died because of CVA events. We had one device stoppage which we implemented corrective action. We have had a wear-out situation at 17 months, and in that particular case, system replacement was considered, but we didn't take the next step of exchanging the system.
What are some of the improvements in the patient activities compared to their pre-operative ICU-bound conditions? They did a lot of the things here, you know, movies, restaurants, and so forth, that we take for granted. We don't even think about it, but for them, because they were close to death, those were extremely, extremely important activities that was worthwhile. Not just for the patients, but for the family and friends. We had one special case here which is a recipient that actually welcomed a fourth generation which otherwise she could not have.
Again, I want to show you just a few clips.
(A video is played)
DR. KUNG: I just want to point out that this clip here, he is actually wearing the electronic vest.
(A video is played)
DR. KUNG: Just summarizing a little bit in terms of -- again, this is an HDE application. Probable benefit is what we're here to talk about, in addition to safety. If we just break down some of the patients, and what their outcome on the left-hand side. There were four patients. Two did not pass the perioperative stages, and two patients didn't get past 60 days. So it's -- clearly in those cases there was no benefit derived by the patients. And on this side over here we had two patients that did a lot of out-of-hospital excursion, and many of the things that I said that was important to us as people that we don't even think about those activities. But it was important to them. Two patients were discharged, at 293 days and 512 days. One of them actually went home for nine months. The other patient actually was in the process of going home, but we discovered that the home electrical environment required upgrading. There was no grounding in the old home, so that actually delayed the discharge, and unfortunately he didn't get to the point that he wanted to get home. And in the middle, obviously the questionable ones because they didn't get out of the hospital. Some of them ambulated. Some of them were able to walk. They did interact with their families and so forth, and this is where, you know, obviously there are some questions regarding benefit, but perhaps there is enough probable benefit. This is all individual because a lot of the families felt that to be very important.
So now I'm going to get into the responses to some of the questions posed by the FDA to the panel. And the way this is structured is not in the exact questions that were asked, because some of the questions could be grouped together. So the little mark here just means that this is relevant to Question 3, okay? And in the next few series of slides, they were addressed to -- they were associated with Question 3, and it has to do with adverse events. The first slide here just summarizes what are some of the adverse events or non-events that we have seen. There was -- we have learned that there are some inflow -- there was some potential cause of probably embolic problems with our inflow, which is the inflow cuff. We identified that and corrected that. We'll come to it a little bit later. Anticoagulation and platelet protocols were refined. At the beginning, in the early parts of the trial, we were still learning in terms of the antiplatelet protocol, and in fact the technology really wasn't quite there for monitoring appropriately the anticoagulation. It was the latter part of it, using something called a TEG, thromboelastogram, which then had additional agonists to detect platelet function. So in the latter part of the trial we were able to use some of those which gave better control, better monitoring of anticoagulation. We haven't had any device-related infection. The sepsis rate is actually very low for the implantable system.
So the first topic that we're going to touch upon a little bit is the neurological events. I mentioned earlier, five of the patients of the 14 died from CVA events. Now, to make -- this is just to put everything in perspective. In comparing to approve established devices that's been sort of in clinical use for the last 15 years or so, that's what these comparisons are. They use basically the same group of references in the next series of slides. What we've plotted over here is the lower bound of the rates. And this is the CVA rate in events per patient month. The lower end and the upper end over here of these published data. When you look at, for example, 0.1, that means the event rate is one event per 10 months. That's what that means. And then if it's 0.3, it's one per three months. This way you can take the duration of support out of the picture. It is one way of looking at this. The AbioCor from the CVA point of view really sort of sits a little bit in the middle part of this, on the higher end. Again, the first time trial, not so surprising. On a TIA basis, or transient ischemic attack basis, it's in the middle, in between the lower and upper bound of these devices. Next on bleeding. Non-surgical bleeding. Again, the lower and upper bounds of these devices are -- we tend to, well, we saw a higher rate, and we believe that the higher rate is because these patients were, you know, had very poor pre-op conditions, and there was also limitations in anticoagulation, which also contributed, for example, to the stroke factor.
On the infection and sepsis point of view, the top one is the sepsis rate, and the bottom one is the infection rate. Very interestingly in the AbioCor, from the sepsis point of view it's on the lower end of established devices. However, in the infection part we saw actually higher rates. And again, perhaps that's just because it's multifactorial, and perhaps you know, just being in the hospital for a long time, which a lot of these patients did, was a contributing factor. But it is important, I think, just to point out that the low septic rate is most likely associated with the fact that we have a fully implantable system with a TET for power transfer. There is no skin puncture.
From the end organ point of view, hepatic and renal, I don't really have much too add. You know, it's pretty much similar to other systems. Just to make a point, that these patients did start out sicker than the ones that were supported by -- which a lot of them were bridge-to-transplant, which were not as sick as these patients that we're talking about from the start.
Anticoagulation. There was a question regarding anticoagulation, how well do we know how to do anticoagulation management. Well, at the beginning of the trial, the anticoagulation was sort of perhaps a little bit simplistic, but it is -- INR target was 2.5 to 3.5, or PTT twice normal. So with that target in mind, just this is what we observed, those patients that were prone to bleeding tend to -- while you can't anticoagulate them as well, they tend likely to have more CVA events. And so if you look at those patients that suffer CVA events versus those that did not, the anticoagulation target, which is what these numbers here, for this group with a CVA, only 20 percent of the time were they in that target range. And they also had higher bleeding rates. And so the lower target rates is because they had bleeding problems, we can't anticoagulate, so that's the sequelae of events. On the other hand, the patients that were free of CVA, the anticoagulation target was around 40 percent. So close to half the time they were appropriately anticoagulated. They also had lower bleeding rates.
We did do refinements on the inflow cuffs. And this is just a very brief summary of what we changed. What we learned during the early part of the trial was that the cuff with the inflow cage, atrial tissue ended up always in contact with that. And so you end up forming a thrombus around the struts. And in fact in all other cases, they had formed thrombus around the -- and that's obviously a likely source of initus for thromboembolic problems. So the design change we made was to make inner waves so that the tissue cannot contact, atrial tissue cannot contact the struts.
And this is very brief, and not intended to be comprehensive here, because this is in some ways, you know, anticoagulation and antiplatelet management is something that one takes a little bit of time to do. The INR and PTT targets remain unchanged. However, in antiplatelet agents that we have used, not all of them, but I mean, different patients they could be different because some may not be tolerable to some of these drugs, aspirin, clopidagrel, and dipyridamole. And from the platelet aggregation point of view, it's targeted at 50 percent functional level. The thromboelastogram is used for monitoring coagulability, and I think that particular instrument is today actually a lot more sophisticated, I think, than even two years ago, in terms of monitoring coagulability.
What will we do in the anticoagulation protocol in the post-approval if that is to be the case? We have learned in this trial that for these very sick patients, the one thing you don't want to do is to increase the flow too fast, because their tissue are friable, and if you, you know, some of them have index of 1.7, and all of a sudden you give them 3.5, it's not a good thing to do because the vessels can't take it, and sometimes you ended up with bleeding problems. So, we'll start out with limiting initially the cardiac output to something like 2.5 to 3 index. And then you can work your way up as needed. Heparin therapy which are standard, you know, you start early after chest drainage as is susceptible, and also that the platelet count is sufficiently high up there so that you don't run into any bleeding problems. And then transmit for a long-term transition to coumadin is done, as long as you know that there is not going to be subsequent re-intervention, or any invasive procedure that may induce bleeding risks.
The antiplatelet therapy would start when the platelet count is sufficiently high, at a level that is sort of on the low, minimum level that you would not cause any bleeding problems again. And that's the 100,000 level. INR, PTT, anticoagulation, you know, that's standard, titration, again TEG for antiplatelet therapy monitoring.
Indications of use. We mentioned earlier this is biventricular failure patients, heart failure patients, high mortality, that can't be saved by transplantation, or LVAD destination. We think that there are some special cases of patients that may also benefit potentially from the AbioCor. Those patients with transplants and are rejecting are not going to have a second chance. That's one category. Angio sarcoma is another category which, you know, they're not suitable to transplantation, and really not suitable for VADS support. And the total artificial heart, especially ventricular sarcoma. Amyloidosis is another case, intractable arrhythmia, some very severe cases where you do need the biventricular support. Septal rupture cases in cases where you can get the patient in time, and that's actually very few of those cases. Similarly on so-called massive MI, they need biventricular support. There's obviously questions regarding how do you get to these patients. And those are practical issues that will limit the number of patients that are going to be helped by this device.
Assessment of biventricular failure. This is another question, and we actually touched upon that earlier. There are two levels, one is the chronic biventricular with poor hemodynamics, clinical assessment, echo assessment, and so forth. Hepatic function. And also, we would like to add the possibility of using the atrial volume index, which I think is actually a reasonable index to use because it measures the cumulative effect of high failing pressure. So you can have high and low, high and low, but over time if the average is high, it -- the response of that is large atrial volume. Or ventricular volume.
On acute heart failure candidates, those that can be reached are supported partially or interimly by biventricular support temporary support. And if they can't wait for that, they're still not transplant candidates, or permanent VAD candidates, then they could be candidates for the AbioCor. With all of this said, we do have that fit, so the fit has to work.
On the training program point. From the training program point of view, those centers that have implanted an AbioCor, every center -- in fact, two centers had only one. Every center, their first procedure was successful, was successful beyond the perioperative period. So what this means, in fact the training program in one or two of the centers was similar to what is described over here, which is center preparation, didactic sessions regarding how the device runs and so forth. In fact, we set up loops for them to play with the device to make sure that they understand the response, how the system responds and so forth. And in addition to that, at least two acute animal implants on the procedural point of view, just to get used to how to put a device in, and how to do the transition from cardiopulmonary bypass to the device. A lot of post-op management and patient care training program that we have established. Obviously right now the training centers that are qualified for training are really Texas Heart and the Jewish Hospital. Very importantly, that the centers have dedicated teams.
Again, a quick summary of what we think the AbioCor offers from the benefit point of view. Some of these, we have demonstrated for example on the bench, reliability of 80 percent at one year with a confidence level of 80 percent. The average run time of devices is around 21 months. And most of the failures were due to soft failures. And soft failures meaning that you can plan -- if you want to consider replacement, you can plan for it. The normal hemodynamics priority allow certain organs a chance to recover. Most importantly, it's really to allow patients and family to have another option to life.
This is just a plot on how the cardiac power, which is a combination of cardiac index and the after-load minus the pre-load, how it changed by about a factor of 2 for the patients, comparing the conditions before and after the AbioCor. Just another case here of a patient with liver problems to begin with pre-op, you know high bilirubin, and obviously with the surgery there's an insult to the system. Bilirubin climbed, but it did take a long time before it came back, but it did come back to normal. So as long as the flow is there, there's a chance for recovery.
(A video is played)
DR. KUNG: This just to reiterate where the patient distributions are. We said that there were four that really did not benefit. There are four of them that really did have a very significant improvement in their activities, and interactions, and so forth with family. And there is that group in the middle, we believe some of them, in fact most of them did think that it was worthwhile anyway, even though they didn't get out of the hospital.
In the post-approval plan, what do we plan on doing? We want to control the introduction in a measured way, so we're not going to try to get into too many centers too fast. So up to about 10 centers in the United States, training and so forth, and having a clinical team to support the centers and the patients. Our plan is to do a complete follow-up. We will monitor, by the way, everything that we have done in the clinical trial in terms of information, data, and so forth, will be done over here. To complete a six months follow-up on 20 patients, and then send a report to the FDA. Now, that doesn't mean that it's going to stop there, because obviously we're going to monitor and provide clinical support to all the patients really for life.
And if there's quality of life in this particular trial, this initial trial, a lot of the patients really were not capable of going through some of the questionnaires, whether it's the Minnesota, or the SF-36. We are going to institute quality of life using the Kansas City Cardiomyopathy Questionnaire, which is a little bit more forgiving from the patient and family point of view in terms of answering the questions. And it gives you pieces of information that are both clinical and patient physical condition-wise.
Institute anticoagulation protocol which we mentioned before. And as far as rehabilitation and infection, you know, our protocols, those will be pretty much following the AHA guidelines.
We have a discharge protocol which has been developed during this trial between Abiomed and the clinical centers, and that will be used. We think that it actually worked out very well for the patient and the patient caregivers.
We'll summarize here what the probable benefit is. Again, what have we observed? We did observe that this device can add another year and a half potentially to patients. Now, it would have been great that if we did it on all 14 patients, but we did show that it can be done. We have not seen any device-related infection. That cuts out a lot of the clinical complications, not only clinical but also for the patients themselves in terms of care and so forth of the exit site. System is very quiet in operation. I think that from the psychological point of view is more than important, to not have to be bothered by a lot of unusual noise from mechanical support devices. Patient on the AbioCor will regain mobility, and some of the minimal kind of activities like showering and bathing will not be an issue. Again, you don't have to worry about exit site wounds and all that. We have the capability, we think, of returning dying patients to some level of normal living. There's enough of a home-monitoring system to allow us to keep track of the performance of the device.
From the safety point of view, again, these are the sickest of the sick patients, and yet despite that, we have found operative mortality was less than 15 percent, comparable to some obviously established complex procedures. We have addressed neurological events through design changes, and also anticoagulation, antiplatelet protocol refinements. We have addressed system failures that we've seen in the clinical trial. The device really does work well in various environments. And this is not a small task, because you go out into the ordinary environment, there are radiofrequencies of all sorts around, and everything has to work. You don't want to interfere with other people, and other people's noises and so forth or signals don't want to interfere with yours. So there's a lot of work behind that. The average testing is around 21 - 22 months.
And finally, we think the use of the AbioCor under an HDE will benefit select heart failure patients for whom there are no options today. This will, in addition, really sort of meet the final phase of the national mission that was started 40 years ago, not by us, in fact by people that -- many of them are not with us anymore, but had the vision to start this national mission.
Thank you very much, but I'd like to, before I stop, since Dr. Frazier, one of the investigators, could not be here today, he got kidnapped by the Russians, and so he's in Russia. That was actually set up a long time ago, and we didn't know about this HDE really only till about two or three months ago. So unfortunately -- but he said please show this, and show my --
(A video is played)
DR. KUNG: Thank you. We have actually a few more minutes, so I would ask, if I could, two of the investigators, and I know that Dr. Dowling and Gray, there will be a lot of questions addressed to them later.
What Dr. Dowling said is he said that everything is probably -- you'll have questions for them. But I'd like to -- you all know Dr. Dowling and Gray, but I want to introduce Dr. Marelli, one of the co-principal investigators at UCLA when one of the implants were done. And so that he could say a few words. And after that Dr. Delgado from THI, Texas Heart Institute, a cardiologist deeply involved in this project.
DR. MARELLI: Thank you for giving me the opportunity to speak.
MS. WOOD: Please pull the mic up so we can hear you. Thank you.
DR. MARELLI: Thank you. I have no conflict of interest save that Abiomed helped me to travel here. There is a couple of points I would like to echo from Dr. Kung, and perhaps add some of my own. The first point I would like to make is that, as a cardiac surgeon involved in the treatment of heart failure, I believe that there will always be a need for an artificial heart. Despite the numerous devices that all of you are familiar with, there are certain groups of patients for whom there are no other options. Many of these patients have had previous valve surgery, they have pulmonary hypertension, and it's very difficult to conceive that all patients have right heart failure only secondary to left heart failure. There are many patients who develop right heart failure, and when we put in a left ventricular device for destination, we unmask right heart failure. So I think that's always going to be a need that we have to address.
The second point I'd like to make is that this device is really a unique design, and represents a giant step forward. A single pump providing the energy for the two circulations is quite an achievement, and that single pump I believe will be very durable. The wear and the soft failures that Dr. Kung described I do not think are related at all to the mechanism of the centrifugal pump that is spinning.
The third point I'd like to make is that the goal of long-term support using the artificial heart will be achieved in stages. It's unlikely that we're going to achieve it all at once, and this I believe is a very good first step. The spin-off technology has been excellent, and I have been very -- I've used the other device technology from this company, and can tell you that it's very reliable, and has saved many patients whose pictures I can show you if you ask for them.
I think the achievements of this trial have been -- one of the important achievements is the absence of infection. And this demonstrates excellent compatibility between this hardware and the human body, which is a large amount of foreign body in the human, and affects the immune system, which we don't have time to discuss today.
Our patient at UCLA was one of the patients who did not benefit from the device. And he is one of the four that did not benefit. I think having gone through the consent process, the implant, I believe that the consent process was very fair and balanced. Our patient's family I still keep in touch with. Everybody felt that we had achieved the goal of first do no harm, and then try to help. And I think that this trial is in keeping with that goal.
DR. KUNG: Thank you. Dr. Delgado?
DR. DELGADO: Thank you. Reynolds Delgado. I'm from Texas Heart Institute. I'm a cardiologist, not a surgeon. I don't implant these devices, don't do surgery. I'm the primary cardiologist supporting the mission of Dr. Frazier, and as such for the last 10 years I've been involved in the management of patients with all types of LVADs that you can imagine. And there is simply a population of patients with heart failure that are not serviced by LVADs. And therein lies the need for this device.
And this device is a conceptual breakthrough because it is a true artificial heart. There's always been discussion since the '60s about what an artificial heart is. This is it. This is a device you put all inside, nothing coming through the skin, that patients can potentially lead a good quality of life with. And as such, it is important for that point alone, but most importantly to service those heart failure patients who cannot be serviced by the LVADs. And I have a lot of them in my practice, and I have no interest in this company whatsoever, financial interest or otherwise, or a competitor of this company. But I have an interest in my patients, and I have a large heart failure practice that I've dedicated my life to, and I want to be able to offer this to those patients.
I took care of the patients that were done at the Texas Heart Institute. We did five. And so I know. I know the problems, the pitfalls, and I know that many of these can be overcome. Some of them will not, but many of them can be overcome. Twelve implants, it's a big learning curve. With any new device it's a big learning curve. With this device, no different. It will get better. We can do better. We can do the anticoagulation better. I know we can because I was doing it, personally, myself, up all night taking care of these patients. So I know we can make this work, and I know it can be a benefit to our patients who are desperate, and who have no other options. Thank you.
DR. KUNG: Thank you very much. I think we are -- thank you for the attention.
DR. MAISEL: Thank you for an excellent presentation. At this point I would like to invite the panel members to question the sponsor. I'd like you to limit your comments only to burning issues, and issues of clarification. We'll have ample time later to discuss things further. Dr. Borer?
DR. BORER: Thank you. That was a very effective presentation. I have two questions. Number one, from the time of the preterminal event in these patients, how long -- what was the interval until death? By my count there were seven patients who have stroke listed as cause of death. How long was it from the stroke to the death? Sepsis, same thing, and the device failure.
And as a second question, do you have any experience with re-implantation? You said that you could, that it was a soft failure, but I see only two device failures on our list, and one of them was a sudden cessation of the pump. So I'd like to know whether there is any experience anywhere with re-implantation, or if not, what do the surgeons think about the degree of difficulty in doing that?
DR. KUNG: The answer to the last one is that no, we didn't. And I'm going to let Dr. Dowling to answer that. And then we'll get back to the earlier questions that you asked.
DR. GRAY: I'm Laman Gray from Louisville. I have no financial interest in Abiomed. I've received no salary from them, nor ever have. We have done a huge amount of the animal implantation. Abiomed did pay the laboratory for the animal work. However, Dr. Dowling and I never received any salary or compensation from them outside of some travel, and a rare honorarium for giving a talk at postgraduate courses.
To answer your question, yes, we think the device can be changed out. We have looked at that actually very carefully, because the device can probably also be used as a bridge-to-transplant. I think that there's a slight difference in how we would technically implant it. It would be implanted similarly to what the CardioWest has done that Dr. Copeland has developed. And what you do is put a GORE-TEX membrane primarily separating the sternum from the heart device. And I think in that situation, yes you can change the device out.
DR. MAISEL: Can you just clarify, are you suggesting that the device can be used as a bridge-to-transplant? Because my understanding of the submission is that that is not one of the uses or indications for the device. Could you please clarify your position on that?
DR. GRAY: What I suggested is yes it could be used as a bridge-to-transplant, no the submission is not for a bridge-to-transplant. But technically I think you could do that.
DR. DOWLING: Rob Dowling from the University of Louisville. I also have no financial interest in Abiomed. To follow up on your question, the other components, two other components have been replaced. The battery has been replaced. Mr. Christerson had a battery failure at about a year, and it was very easy to replace, about a 45-minute operation. That is the component that's most likely to need to be replaced, a very simple surgery. The TET coil needed to be replaced in one patient. It was also a very straightforward operation.
And I would reiterate what Dr. Gray has described. The group from Arizona has demonstrated techniques to facilitate reentry in artificial heart recipients.
DR. BORER: Can I just ask, while you're still up here. My greatest concern as I watched this was the availability of a reconnection site in the atria. You know, you used up some tissue to sew in the artificial heart the first time. Is there sufficient tissue so that you could make a mechanically viable connection the second time?
DR. DOWLING: Yes, that's an excellent question. If you look at the device that Dr. Frazier's holding, you'll see the cuffs. I can point them out to you. Those are -- we remove the ventricles. We leave the entire atrium and the annulus. The annulus is a nice tissue to sew to. So we sew the atrial cuffs to the level of the annulus. And then the atrial cuffs have quick connects which allow us to just snap them onto the heart. So at the time of re-operative therapy, the goal would be to just simply leave this attached to the atrial tissue, unsnap this quick connect, and put it back in. And I can tell you that in the early experience, we have had some in the animal lab where there was a problem with the pump, or it got contaminated or something, and we switched them out, and it takes a matter of seconds. So I think the hard part from the surgery point of view is getting to that point. And once you get to that point, you're just going to snap it off, and put a new -- put an elastic unit in, leaving these in place.
DR. MAISEL: Are you able to pass that model around for the panel? Can we take a look at that?
DR. DOWLING: Yes, absolutely. We didn't want to do it during the talk.
DR. MAISEL: Any other burning issues? Mitch.
DR. KRUCOFF: Just one quick question. On the cage modification, my understanding was that there were concerns originally about thrombus, and that later the cage was modified to keep atrial tissue further away. Do you have postmortem observations on the latter on your last three patients or so?
DR. GRAY: Yes, we do. As a matter of fact, I think one of the -- if you want to get into it, now one of the major discussions which needs to be discussed is the whole stroke situation.
DR. KRUCOFF: Actually, I don't, I just wanted to ask one quick question, which is on postmortem, on the modified cage in the last three or so patients, what did you see?
DR. GRAY: We have some pictures of it. It was well implanted with tissue in-growth, with no evidence of any thrombus.
DR. KRUCOFF: Thank you.
DR. GRAY: And we'll have a picture. It's actually extraordinarily -- if you look at the upper right-hand picture, this is the modified cage. The modified cage, if you can see, there is excellent tissue in-growth in and around the -- this is the cage part of it. There's actually no thrombosis around any of it, and all of the last three patients for this was done, and it looked exactly the same. And it's extremely encouraging.
DR. MAISEL: Thank you. Dr. Somberg?
DR. SOMBERG: A couple of quick questions. One is CVA seems to be the limiting factor for improvement in five of the 12 patients. I wondered if you can just list what the other major factors for not being able to leave the hospital, or exercise the full benefit of the pump system? And then I have two more about the device itself.
DR. KUNG: All right, just give me a second to ¼. I hope this is -- yes, I think it's readable.
DR. GRAY: Basically, to answer the question in a nutshell, there were two operative deaths. The other problem besides CVA was the two device failures, and then multi-organ failure was the other major problem. In multi-organ failure, if you really go down, we can go to each and every one of them actually. We'll want to do that when we start talking about the stroke problem.
DR. MAISEL: Can you please speak into the microphone a little more? Thank you.
DR. GRAY: Yes. But multi-organ failure is the primary cause of death when -- outside of a stroke.
DR. SOMBERG: So really, patients are either so ill that the pump doesn't offer them benefit, or the device, or you seem to have a coagulation problem with either bleeding or a CVA.
DR. GRAY: Yes. And if you really want to get into it, which I don't know when you want to do this, but we want to go into it. Because one of the real problems, I think, with the stroke is related out to the anticoagulation.
DR. SOMBERG: My other two questions are I noticed in the one outstanding result was the membrane life was a problem. And there's also a reliability of 80 percent. And I wondered what is the rationale for not having a component that would potentially last longer, or only have a reliability of 80 percent, and is there a plan to rectify that?
DR. KUNG: Over time the system is improving. The 80 percent and 80 percent have, believe it or not, actually originally was -- actually it wasn't even 80 percent/80 percent. One of the original NIH definitions for long-term support device to get into clinical trial was 80 percent reliability at one year, with 60 percent confidence level. Now that was actually published many, many years ago in Anderson for thoracic surgery. So we have achieved, you know, the 80/80 for one year. And it was mentioned earlier that over time, the device average run time is increasing. And so there's going to be improvements going forward.
DR. SOMBERG: And the component, the component wear-out at a certain period? What is the plan in terms of trying to deal with that?
DR. KUNG: We are actually dealing with that right now, but we don't have the information to say that, okay, it's got extended life. But what we're doing right now, our testing is going in that direction. And it is important to understand that that in and of itself is not a heart failure. So you can anticipate what's coming.
DR. MAISEL: Thank you. Rick?
DR. DOWLING: Maybe just to follow up on that. There had been some software changes that Bob is more familiar with than I am. But if you remember the video that showed the membrane shuttling back and forth, a lot of attention was paid very early to making sure that there is minimal contact when the membrane went out and touched the lateral wall of the pump. Not so much attention was paid to making sure that there was a soft landing when it moved in toward the energy converter. And what we saw in the pump that clinically had the wear-out at 17 months was that the abrasions were on not the lateral wall that we were focused on, but on the medial aspect of the pump. So Bob you can correct me if I'm wrong, but I think there is some software changes that have been made to make that more of a soft landing on both aspects of the pump, and that in and of itself will hopefully improve the durability of the membranes.
DR. MAISEL: Thank you. Rick?
DR. PAGE: Thank you for your presentation. I'm trying to understand what it's like to live with this device in place, and while we've seen the patient fishing, and going and visiting, and the parade and the like, how much time during the day is the patient connected, if you will, to the home console, and how much time during the day are they carrying around the handheld battery pack? And are they wearing that vest during the day? So give me an understanding of how connected the patient truly is to outside equipment throughout the day.
DR. DOWLING: The vast majority of the time the patients are connected to some -- to the external power supply. The battery initial -- the internal battery initial life is probably a little bit less than an hour, and of course degrades with time. One thing we have learned in the clinical trial is that there are protocols we need to do. We need to run that battery down every day, or at frequent intervals, to try to improve the duration of the battery life. So we want them to be off and unhooked for periods during the day.
People can wear the vest if they want to. There's a real nice Velcro belt that you can attach the batteries to that works remarkably well. And if you're just sitting it's just sitting in a pack next to you. I would contrast that to all of our LVAD recipients who have it 100 percent of the time. And I can tell you, we implanted -- there's only two implantable systems available. We've implanted both the implantable LVAD and obviously this system, and the difference it makes in terms of the impact of just being able to get up and go to the bathroom, or shower, is just incredible. So that may be that 10 or 15 percent of the time of the day when they're totally untethered makes a real, real big difference to those patients.
DR. PAGE: Okay, thank you.
DR. KUNG: Just to add a little bit to that. The external little pack is actually -- can run for two hours. And then it's rechargeable, so you have to switch the batteries. Now, when a patient is sitting and really not moving around too much, you can actually connect it to a wall plug so that you don't have to use a battery.
The console is used if you need to get real-time information from the system. Otherwise, the console is not -- you don't have to be attached to the console.
DR. PAGE: Thank you. And another practical issue, the charger has to be correctly placed, and attached to the skin. And that requires what appears to be a fairly permanent adhesive on the skin with the attachment of the Velcro. Am I interpreting that correctly?
DR. KUNG: Yes. What you saw there is Duoderm.
DR. PAGE: Right.
DR. KUNG: It's Duoderm, and then we have a little -- we probably can show you what it is. Velcro. By the way, the system was designed in a way that it does not require exact alignment. It's actually pretty forgiving. You can have a lateral motions of up to about 3/4 of an inch from center, and up and down it can be off by quite, you know, almost the same amount, 3/4 of an inch.
DR. PAGE: Have you run into problems with skin sensitivity, and how would you deal with that if a patient is intolerant of having adhesive at that site on a permanent basis?
DR. DOWLING: Sometimes Bob forgets he's not a medical doctor. So, it's the same type of stuff that the nurses would use for stoma. Of course, it's a lot easier because, as you saw in the picture, you don't cut out the center. The average time, if you talk to the nurses, that they have to replace it is about a week. And maybe Patty can tell us during the break if that's the case when they were at home.
There are other methods to attach it. We haven't had any problems with skin sensitivity that have been significant. When we have, which I don't remember offhand, we can ask the stoma nurse, or people. So I don't think it's going to be -- it has been a very low incidence. I'm not even aware of any, and certainly it is the type of thing that is used very often in other clinical scenarios.
DR. MAISEL: Thanks Rick. Gene?
DR. BLACKSTONE: I wanted clarification of Slide 55, which gives just point estimates of this 21.6 months that you talk about. Could you tell us what the distribution actually is of your failures or run time?
DR. KUNG: Okay. I don't think I need to go to that slide. You just mentioned the number. What -- it's typically -- it goes out one year, and then from then on the failure rate is approximately 4 percent per month.
DR. BLACKSTONE: Okay.
DR. KUNG: From then on it's sort of a linear. We have had -- again, we have had systems that have gone out actually more than three years. But, so it's pretty reliable out to one year, and then it's linear.
DR. MAISEL: Joanne?
DR. LINDENFELD: Just a brief clarification on your Slide 23 that compares the patients that were turned down for the Abiomed with REMATCH patients. Is that the REMATCH patients on inotropes, number one, and number two, how many of the patients that were turned down withdrew support? In other words just ¼.
DR. KUNG: Let me make one clarification, and maybe, you know, maybe you'll want to chime in. But we were not getting -- the comparison is with OMM of the REMATCH patient, but we never got any -- this has nothing to do with REMATCH.
DR. LINDENFELD: I totally understand that.
DR. KUNG: Oh, okay.
DR. LINDENFELD: I'm just asking you, since we'll talk later about this require inotropic therapy, I wonder if your control group that you pictured was the group, the OMM group on inotropic therapy, number one. And number two, just because it's an issue of the seven patients that you use to demonstrate a dismal prognosis, how many of them withdrew support when they were turned down for the Abiomed device?
DR. KUNG: Some of them went through the screening and they didn't fit. The device didn't fit. We went through the fitting program so it didn't fit. And then some, actually a few of them I think died before we could even get to them. And then there was some others that actually went through it and refused, or declined.
DR. GRAY: There were none of them that actually support was withdrawn from, of that group of seven. They were continued to be treated maximally medically until they died.
DR. MAISEL: Clyde.
DR. YANCY: One point of clarification, please, on your statement on one of the summary slides that it adds up to one and a half years of potential life. Is that based on the failure rate on the bench, or your clinical observations? Because only one person went past one year.
DR. KUNG: That's just the fact that we have -- you know, we, on a feasibility basis, we've shown one patient can go to one and a half years.
DR. MAISEL: At this point I'd like to take a break. It's 10:10. We'll resume at 10:25. Thank you.
(Whereupon, the foregoing matter went off the record at 10:12 p.m. and went back on the record at 10:31 p.m.).
CHAIRMAN MAISEL: Let's get started, please. If everyone could, please, take their seats. Good morning, I would like to invite the FDA to begin their presentation, please.
MR. CHEN: Okay. Mr. Panel Chair, ladies and gentlemen of the Panel, I would first like to thank you for taking time out of your busy schedules to come participate at this Advisory Panel. As mentioned previously, for the record, the device that is going to Panel today is the Humanitarian Device Exemption Application H04006 for the Abiomed AbioCor Implantable Replacement Heart.
My name is Eric Chen. I'm the current team leader for VADs, Ventricular Assist Devices, and Total Artificial Hearts at the Agency and I was the lead reviewer for this application.
Just to go over a brief overview of the presentation, as you may have already heard, it's an HDE device. I'll go over a brief background. Information is what is an HDE? I'll also be presenting a history of the feasibility study, some engineering clinical evaluation that the Agency has reviewed, and Dr. Julie Swain will be presenting the clinical evaluation after my presentation. And concluding the FDA's presentation today in the afternoon session, we will be discussing the Panel questions.
Since this was a complex device, the Agency had a variety of specialists that were called upon to review this application. I have listed the names of the individuals here for their recognition. As the Panel may have already heard in the private session, this is an HDE application, so according to our HD Regulations, an HDE application is similar in both form and content to a premarket approval application. However, it is exempt from the effectiveness requirements of the PMA.
And an approved HDE authorizes marketing of a humanitarian use device, which is an HUD. I would like to point out that the safety criteria, however, for the HDE is very similar to that seen in the premarket application. A humanitarian use device is a device that is intended to benefit patients in the treatment and diagnosis of diseases or conditions that affect or manifest in fewer than 4,000 individuals in the United States per year, and this is from our Federal Food, Drug and Cosmetic Act.
So going back into the presentation of the device today, the sponsor has already gone through a pretty good explanation of the device. I have two pictures shown here. The picture on the left, you have seen before, consists of the system that is implanted in the patient. You have the thoracic unit, the implantable battery, the implantable controller and the implanted TET coil that allows power transfer across the skin.
The picture on the right is a cutout model of what the device would look like if it was implanted in a patient. As you can see, the operation to implant the device is very complex in that the ventricles are resected in order to implant the device. So once you go in, it seems or it appears that there is no turning back. And you can see in the bottom of the cut away, you see the implantable controller and batteries in the lower abdomen.
Here is an up close picture of the device. The sponsor has given a very good description of it. In the upper right hand corner of the device, you can see the balance hydraulic chamber that the sponsor has explained that allows for the physiological shunts that humans have for the right and left balance. And the device has the ability to compensate for that balance.
The proposed indications for use in this HDE application that the sponsor has requested is that the AbiCor is indicated for use in severe end-stage heart disease patients who are less than 75 years old, are not transplant candidates at the time of assessment, require multiple inotropic support or bi-ventricular failure not treated by a destination therapy LVAD and are not weanable from a bi-ventricular support and not awaiting transplantation.
I would like to point out to the Panel that this population that the HDE is proposed is that the patient population is different than those studied in the REMATCH and different from the SynCardia Systems Temporary CardioWest Total Artificial Heart that was discussed at Panel last year. And the underlying sentences differentiate the reasons for their differences.
The U.S. Feasibility Study was approved in January of 2001. It was a single arm perspective feasibility trial to determine safety of the device. The initial sample size included 15 patients, however, at this time, only 14 patients have been implanted. The feasibility study included approval for six investigational sites, however, only four have perspectively implanted these devices. There was no perspective statistical plan or control group in this feasibility study, because feasibility studies are normally to demonstrate safety of the device and not effectiveness.
The Agency believed that since it was a complex device that there would be an incremental gate for study continuation, meaning that the first criteria was that if none of the first five patients had survived to 30 days, then the feasibility study would be stopped and no additional patients could be implanted. An additional criteria that the Agency believed would prevent additional harm to patients is that at least one out of five patients in a set of five had to survive to 60 days without any major complications in order to get to the next set of five.
As pointed out, there was a slow enrollment for this trial. 14 patients took, approximately, roughly four years to complete. Candidate selection process occurred in two stages. The first was the screening stage which determined the severity of heart failure, and this was done by the sponsor's proprietary scoring system, known as the AbioScore, which Dr. Julie Swain will be discussing in her presentation, and as well the potential fit of the device from CT and MRI scans. And in conjunction with that, the sponsor had their own proprietary virtual surgery program called the AbioFit that they used.
If a patient had qualified through the screening process, then they would go move on to the implant consent form process. So we've touched briefly about the HDE Regulation and I would like to bring us back to what portion of that we want to worry about today is that for an HDE application, the data in the application must show that there is a reasonable assurance of safety and probable benefit in the patient population that is intended.
An HDE application must demonstrate that there are no comparable devices available, at that time, as well the data must demonstrate that the probable benefit of the device outweighs the probable injury. According to the HE Regulations as well, the clinical data does not have to come from a controlled clinical trial. The clinical data can come from clinical experience with the device. However, with most HDE applications, the Agency recommends that there at least be some clinical experience prior to HDE application.
So my engineering background and the specialists that were involved, we reviewed portions of the preclinical evaluation or the engineering aspects of the device, and we determined that the following aspects were deemed satisfactory, the alarms, battery performance, biocompatability of the device, the device to function electrically safe if a patient decided to go to a hospital or go to the mall or anything like that, and the software and sterilization was also deemed to be satisfactory.
One aspect that was of concern was the reliability of the device, which has been discussed briefly, and those two aspects that were discussed was the membrane wearout and the bearing failure that was seen. So I would like to briefly discuss the reliability testing that the sponsor has performed so far. 25 units were placed on reliability tests, mock loop and the implanting components were implanted in the usual and customary 37 degree saline and so forth.
The failure times, at the time of submission, ranged from 8.2 months to 40.5 months and the average run time was 18.8 months, but you have heard that the sponsor has updated that to, approximately, 22 months. Reliability was deemed to be greater than 80 percent at a confidence interval or confidence level of 80 percent at one year. The Agency does believe that this is adequate to demonstrate reliability for the device.
As mentioned previously, there were three failure modes that were seen. One was a membrane wearout, a bearing failure and fluid ingress, and these were issues that were seen by the sponsor in reliability tests. The fluid ingress was not seen clinically and the sponsor has corrected that issue.
Clinically, however, there were two device failures. Patient No. 2, there was a membrane wearout at 17 months. This was the expected failure of the device. The patient refused to have the device replaced and subsequently died because of that. The sponsor has proposed to some corrective actions in order to expand and extend the membrane device, the membrane wearout of the device and the Agency and the sponsor will continue to monitor this membrane wearout.
Patient 13 involved a bearing failure that occurred at five months. This was an unexpected device failure in that the position of the AbioCor at the time of placement was different than the preplacement CT scans, which caused a decrease in inflow into the pump, therefore, in order for the pump to compensate for that, the pump had to increase hydraulic power and increase beat rate. So, therefore, the pump experienced excessive bearing failure for this. And the sponsor has provided corrective actions to the Agency, which the Agency has deemed to be acceptable.
So to summarize, replacement of the device requires major surgery. We have heard that batteries and TET coils have been replaced so far. However, no AbioCor implantable thoracic unit has been replaced, but it seems to be feasible that this is an option. Device end-of-life behavior was seen on the bench and clinically seen in the two device malfunctions.
So, therefore, the results of the preclinical testing in conjunction with the outcome of the reliability results from the clinical trials suggests that the device performs according to specifications. And I will now turn over the presentation to Dr. Julie Swain, who will present the clinical aspects.
DR. SWAIN: Thank you. The Review Team, Clinical Review Team for this device included Dr. Ileana Pina, Heart Failure Cardiologist, and she is available to answer questions today. Also, our Statistical Team, including Dr. Hang Lee, who is here today, who is head of the Cardiovascular Statistical Group.
The first thing I want to say is that it has been really enjoyable working with this sponsor. I think that they have high ethical standards and are very honest and have provided all of the information that they could answer that we have asked for. So I'm very happy with the interaction that we have had. There is two reasons that we presented, we wanted to bring this to the Panel today.
The first is that it's not a clear cut decision and we really want the expertise of the Panel in reviewing these cases. And the second is I think we correctly anticipated a high public interest of this device and this is the only way the Agency really has to get data to public view and to make appropriate expectations for devices that have a high public interest that some of the data may be misinterpreted.
So first of all, this was a multicenter feasibility trial as Eric has just said. 12 of the 14 patients were implanted at two centers. And the indication for use for this is designed as transplant ineligible patients and we wish to discuss that, end-stage heart failure, we'll also discuss that, and bi-ventricular failure. So those are three areas that we have some questions on and wish to have some discussion on.
Now, besides that indication, the proposed HDE inclusion is the heart failure patients who are on optimal medical therapy and meet all of the following. And I won't discuss the optimal medical therapy any longer, but the data provided to us was difficult to judge how optimal the medical therapy was on these patients. The proposes inclusion is less than 75 years-old. Now, two of the patients were 79 out of these 14. They are not transplant candidates, estimated 30 day survival of less than 30 percent, bi-ventricular failure, multiple inotropes or temporary BIVADs.
When you look at the proposed additional inclusions, which are on page 69 of the Panel pack in the post-approval study, the sponsor also claims that patients with contraindications to LVAD placement, and that was mentioned in their presentation, would also be included in these indications. And that is not what the HUD was approved for and there is a question about whether one would go under the 4,000 -- over the 4,000 mark if one included all of these indications.
In particular, look at the massive MI, patients who are at risk of inlet cannula dislodgement, that would be the interior MI patients, which made perhaps Dr. Frazier's last comment about the 39 year-old with the massive MI that he lost the week before and would be a candidate for this device, that's probably not the case. The Agency would very much like to see clinical trial proposals for this particular indication, but it is not part of the -- or these indications, but these are not part of the HUD designation. It also should be noted that none of the 14 patients in the feasibility trial had any of these indications.
Well, what about the controls? It was said that we had no agreement ahead of time, because this was a feasibility trial of a controlled population, and we have really no data on the seven patients that are now viewed, you saw in the KM curve, as part of the control. So when we look at controlled populations, we have a little bit of a problem comparing these.
First of all, to compare it to the REMATCH control patients, we think is really inappropriate. There has been a lot of changes in medical care since that population was designated in the early 1990s. These are different patients in REMATCH than in this feasibility trial. And it is a subset analysis of only 61 of the controlled patients in the REMATCH, many of whom withdrew from care after they lost the coin flip and were not going to get the destination therapy device.
Also, the sponsor has discussed the AMI-SHOCK index as a way to predict mortality, but none of these patients have an acute MI, so they are not comparable. And then we have the AbioScore and this is based on a 42 patient chart review prospective and retrospective records using ICD-9 Codes. The age of these patients were 20 to 79, very different from the patients in this feasibility study. 26 percent were female in the 42 patients, none in the feasibility study. And probably most importantly, 38 percent of these 42 patients were on LVADs for a bridge-to- transplant, and that's different than these 14 patients, none of whom were judged to be transplant candidates.
So we have a problem with the validation of the AbioScore. We do not think it is validated satisfactorily and we have Dr. Hang Lee if you have any further questions statistically about the validation on that. However, the AbioScore is really based on 27 items that clinically we used to judge expected mortality. The components include most of these items, although the validation of this score, we believe is unproven, there really is no known predictive system for predicting 30 day mortality in this group of patients.
These were very ill, malnourished patients. However, when I see that, you know, the seven control patients lived an average, I guess, of two weeks, that's one of the public perceptions that I think we need to be very clear about is that we don't know how long these 14 patients would have lived and we don't have a validated predicting scoring system for that.
Well, what's the reasons for non-transplant candidacy and some of the information on these slides is slightly different than what is in the Panel pack. It was based on the earlier submission. But five of the patients were excluded solely for age, two of whom were 79, one was 70 and then ages in between 70 and 79, and there are various other reasons for excluding patients. We know that there is really no national standard for transplant candidacy, so the question when you all review these clinical summaries is would that be a patient who would be perhaps a transplant candidate at your institution or in your practice?
What about the ages at implant? Here is the distribution of ages of these patients, and again two of the patients were 79 years-old and one of the patients was, I believe, 51 years-old. Then the question comes about right ventricular failure or bi-ventricular failure and the mean CVP was instead of 9.6 in the earlier submission, it was actually 11.0, and the pulmonary artery pressure of 34.5 with an index of 2.1. And the question is is that a population that is normally defined as right ventricular failure with those right side filling pressures?
Now, this is a slide we had and I have to tweak the sponsor a little bit, they had our slides available and we didn't have theirs, so they modified our slides a bit. But first of all, when we hear the term operative mortality and then compare it in the sponsor's presentation to things like MVR cabbage and the STS database. STS database, the definition of operative mortality and the definition we normally use in the cardiovascular surgery community is death within 30 days or before hospital discharge, whichever is longer.
Going by that definition, 12 of the 14 patients in this feasibility trial had operative mortality, which is 86 percent. So one has to be very careful comparing kind of apples and oranges. So acute operative mortality in this trial was two patients, but true operative mortality was actually 86 percent. And I think all of us agree on the left side there of the four patients with no benefit. And one of whom in the original description of the clinical course was a patient who lived 53 days and was described as really not regaining consciousness and the family requested withdrawal of support, otherwise, the patient may have well made it over the 60 day mark.
And on the right, we do have a patient who was actually discharged home. And in the middle we have got this group of patients, including the days of support there, that there is a real question about. And I think that reading the excellent clinical summaries provided by the sponsor will let each of you judge as well as you can what the real benefit was.
Now, this slide shows the days of support for each of the patients. The first thing that you can see is that there is probably no demonstration here of a learning curve, meaning an incremental benefit with time. And you can see the green bar across the median, is the median days of support 112. And again, when we hear potential support adding or increasing life for a year and a half, that's one patient and we really don't have support for that in the other 13 patients.
The other thing here is this is just the quantity of life and what we really care about is the quality of life. It's prolonging life, not prolonging death. And you need to make that judgment looking at these clinical summaries on the patients. And, you know, it's somewhat difficult to make that judgment based on the data that we have.
Well, when you look at SAEs and SAEs were, you know, fairly severe in these patients and the bleeding definition is 2000 ccs of blood loss within 12 hours or take back for bleeding or relief of things like tamponade. So we look at the number of AEs in each of the patients and the small numbers at the top of the bars are the days of support, so if you have, essentially, an operative death, you will find very few SAEs. And then the little red bars at the bottom of the big bars is the SAEs that occurred within 60 days. So it appears that the SAEs are definitely not front loaded in that they occur over the course of survival of these patients.
What about the cause of death? The Agency's definition of stroke is a neurological deficit that lasts over 24 hours or lasts less than 24 hours and is associated with infarct on an imaging modality. So by that definition, we have defined CVA, MTIAs in the rest of this presentation. So from our review of the records, it appeared that seven of the patients died from CVA and the sponsor, during that presentation, did not discuss the CVA aspect, although it is in your Panel presentation and your Panel materials.
Two acute operative deaths, two pump failures and then multi-organ failure. The SAEs out of the 12 patients where you could measure SAEs who survived the acute operative procedure, that there were the 19 strokes in nine patients, nine of the 12 patients, and then we see 4 TAEs bleeding infection renal failure. It's important to note that there appear to be no systematic neurological examinations by neurological experts in these patients.
And we recommend for the last several years that patients undergo a neurological evaluation, standardized such as NIH Stroke Score, as well as basic cognitive functions, so that we can have a better idea of the quality of life of the patients who are surviving. And when we look at this quantity of survival, it is impossible by looking at these records to understand how many actual days of life the patients had with what one would generally consider an adequate quality.
And very often we look at the Rankin Score, modified Rankin Score, which is a way of generally measuring that and a score of 3 or better is moderate disability or better. And we really don't have enough information to categorize this on these patients. And then there is, as the sponsor pointed out, bleeding problems and anticoagulation was a problem with this. And when we look at the number of instances over the 14 patients, again, we don't see a big evidence of a learning curve, such that there would be a lot of complications in the early patients and then less as time goes on.
What about functional measurements? Well, there were really just no validated measures of quality of life in these patients. We have occasional notes that we can see them walking and taking excursions and things of that sort, but none of these patients had anything that we could really, validated-wise, compare it to any other device. Therefore, it makes it difficult to understand the functional level and to balance the high mortality in these patients and the adverse events with a true improvement of quality of life.
So in summary of the clinical data, these were implanted in patients who, in the judgment of the clinical center, the two main clinical centers that did the patients, to not have any other options to prolong survival. The device pumped blood well. It provided physiological cardiac output and pressures. Some of the patients had improvement or stabilization of their end-organ failure and some of the patients could sit, stand, walk, take excursions out of the hospital.
So our clinical summary is that the risk benefit determination for this device is difficult due to the lack of validated QOL and functional data and we wish the expertise of the Committee to comment on this area. Thank you. Oh, sorry, post-market study. We have several items, if this is approved for marketing, to discuss and they include what should be measured.
We think that one should, of course, look at the preimplant status, but we should also carefully look at major adverse events, including neurological, careful neurological examination of these patients and scoring them with the use of something perhaps like the Rankin Score. Certainly, as the sponsor proposes to death or device removal and then the question is the sponsor proposes, approximately, 20 patients, statistics really aren't possible in this group of patients, so your judgment on how many patients it would be appropriate to follow post-marketing. Thank you.
CHAIRMAN MAISEL: Thank you very much. Any questions from the Panel for the FDA? Sharon?
DR. NORMAND: I have a question regarding the patients included. I noticed there were no females and I was wondering whether or not the size of the device is such that it wouldn't typically be used in a woman. I mean, I don't know if the FDA -- if that's --
CHAIRMAN MAISEL: Actually, why don't we hold off on sponsor questions now.
DR. NORMAND: Oh, well, so the FDA can't answer that?
CHAIRMAN MAISEL: Is the FDA saying that they don't have a comment on that?
MR. CHEN: To my understanding, and the sponsor can correct me on this, is that the minimum BSA is around 1.7, 1.8, so I would think it would be very hard for a female to get implanted with this type of device.
DR. NORMAND: Thank you.
DR. LINDENFELD: May I just, as long as we're on that subject, add to that? Where do you put the TET coil in women?
CHAIRMAN MAISEL: Why don't -- let's hold off on sponsor questions for right now. Let's focus on questions for the FDA and their presentation. Mitch?
DR. KRUCOFF: Eric, obviously, in the HDE, I think we're clear that it's probable benefit and not effectiveness. But with the emphasis on safety, I guess what I'm wondering is I don't understand the absence of any sort of safety analysis plan. So can you help me grasp where your perspective of safety, which is important for an HDE decision, comes from?
MR. CHEN: From an engineering aspect, I personally feel that the Agency does not have any concern with the safety of the device. Even though there were two device malfunctions, one being the membrane wearout and one being the bearing failure, the sponsor has appropriately submitted an IDE supplement to correct that failure, and the Agency found the information provided adequate to determine that the bearing failure malfunction had been fixed.
However, for the membrane wearout, we're currently still in discussions with the sponsor on that. The sponsor has proposed some corrective actions and the difficulty of seeing if the reliability of the membrane wearout can be expanded or extended, obviously, is difficult to see from the patients since only one patient survived to 17 months.
But as an engineer, I feel that the testing that the sponsor has performed and the corrective actions that they have proposed would lead me to think that the device is reasonably safe on the engineering aspect.
DR. KRUCOFF: Okay. Let me ask you and then I'm going to pick on Julie on the clinical aspects. On the engineering aspect, we have heard about a couple of modifications that you all have reviewed and then there was the cage design that has been reviewed.
Summarily, is your sense that the device we are actually talking about that would go to market an iteration of the device that was used in the initial research or are we talking about different devices?
MR. CHEN: My understanding is that the first six patients were implanted with the cage and then the next three were without the cage, because there was discussions in that thinking the majority of CVAs seen at the early front were because of this cage problem and tissue ingrowth into the cage and so forth. So the sponsor came in and requested that the cage be removed for the next three patients, and that was done.
However, CVAs were seen with those three patients as well. The clinical staff of the private investigators and the hospitals had made changes to their surgical techniques and so forth to accommodate the missingness of the cage. However, there was no conclusive data from the first six patients and the next three patients as to if the cage or if not the cage was the cause of the majority of the CVAs.
The next three patients were also implanted with the cage, with the modified cage. So in that aspect, I don't personally think the device has changed too much. I think the operative techniques and management of the patients is what has changed.
DR. KRUCOFF: Okay. So, Dr. Swain?
DR. SWAIN: Well, you know, it always depends on your definition of safe. You know, we have a President who couldn't define "is," so it's a problem, because, you know, I think the stopping rules that were designated at the beginning of this trial, they had three segments of five patients a piece and one patient had to go at least 60 days neurologically intact to get another group of patients, and they have certainly exceeded that.
So I think the stopping rules were actually very conservative and they won on the stopping rules. So that is what led us to this path of having 14 patients and then evaluating it in the future for a pivotal, but decided to switch over because of enrollment. We certainly have no reason to believe that these patients were not extremely ill and that the planning institutions felt that they would be dead within a month.
So when we look at the results of this, we have to put it in context of the expected patient population and the results we have. So I have no problem looking at this and saying that it is reasonably safe for that group.
DR. KRUCOFF: Okay. So you have a very talented statistician on your team and, as far I can tell, he is the most under-utilized member of the team in this plan. In a patient population whose mortality is 100 percent at 30 days, what would the rationale be? If that's the theory, what would the rationale be for an HDE path rather than a meaningful analysis plan and a clinical trial?
DR. SWAIN: That's interesting, because the Agency has a regulation about HUDs and HDEs. The sponsor chose to go this path. We're reviewing it on this path. And you look at four years enrollment of, essentially, only two institutions out of the six being able to enroll in four years. It's a difficult patient group perhaps. And that's what we're asking this Committee, is to balance in the data that we have, are there adequate data to balance, to determine whether there is probable benefit for this device.
CHAIRMAN MAISEL: I would also remind the Panel that we are not here to debate the HUD/HDE issue today. Good.
DR. KRUCOFF: Yes, but we are here to understand what safe is.
DR. SWAIN: Yes. And statistics on n=14 is somewhat difficult in a patient that is a heterogenous group.
CHAIRMAN MAISEL: Chris?
DR. WHITE: Julie, when you look at the co-morbidities, the strokes, 50 percent by the FDA number, 7 out of the 14, is there not a role for more animal testing? If this is not a device-related problem, why are we not running these devices for years in a pig or a swine or why are we not solving the problems of stroke if it's a device-related stroke before we get to these very, very old patients, because they are so confounded in these very old patients?
DR. SWAIN: Well, see, I think that this is exactly why we wish to bring this to the Panel to use everyone's clinical judgment. Most of the time you all can figure out what I think about a device when I'm presenting, but this one I think is a real dilemma when you look at the patient groups that were studied and the results in that patient group.
And long term animal studies on these devices and the history of our official heart devices probably haven't been as rewarding as far as predictability in patient clinical outcome as we would hope. So the correlation is not that great. So I'm--
DR. WHITE: For stroke? Specifically for stroke, Julie?
DR. SWAIN: Yes, specifically for stroke. So I don't particularly feel strongly that additional animal testing would have helped a great deal in this. I wasn't involved in the early part of the Agency approval of this, but I think I agree, looking at the previous data, that this was a very appropriate device to take to a clinical trial.
CHAIRMAN MAISEL: George?
DR. VETROVEC: Yes, back to Dr. Chen. I'm just bothered somehow by the summary statement that you made. You said the results of the preclinical testing in conjunction with the outcome of the reliability results from the clinical trial suggest that the device performs according to specifications.
I mean, how do we know what we should specify, I guess? What should we be trying to specify? I mean, we have had a couple of patients die of device failure. I'm just confused by that term.
MR. CHEN: Well, I guess for all applications, HDE or PMA, and in any development of any type of medical device, the sponsor has to come out with some types of specifications that they think their device can meet, and then they go through validation testing, through reliability, animal and in vivo and in vitro testing to demonstrate that at least the device can function close to that specification. And then they also try to push it past that specification to see how far they can actually push it.
So in my engineering view, I believe that the device has functioned according to the specifications that it can pump blood. It has shown that the reliability can last up to 17 months or, well, 21 months on the bench now, and that to my knowledge there have been no software issues with the device. The TET coil system hasn't affected a patient's skin or anything like that and the console and the portable console and the PDA that the sponsor have developed have all functioned according to specifications.
So when I make the statement that the device has functioned reasonably, close to that specification is where I'm coming from as an engineering aspect of it.
CHAIRMAN MAISEL: George?
DR. BLACKSTONE: I'm sorry.
CHAIRMAN MAISEL: Gene?
DR. BLACKSTONE: I hate to be a contrarian. However, in the sponsor's presentation on the FDA's slides and in their comments, they specifically mention the extended indications for this device. I don't see, because both the sponsor and the FDA has presented this information and asked for comment on it, that we can with blinders ignore the HUD question, because it is being raised by both sponsors and FDA.
CHAIRMAN MAISEL: I mean, we can ask for a clarification from Dr. Zuckerman, but my comment would be we're asked to answer whether the data presented provides information that allows us to answer the question of whether there is safety and probable benefit for the HUD and HDE exemption.
Dr. Zuckerman, would you like to comment?
DR. ZUCKERMAN: Yes. Hopefully, this will be a point of clarification. If not, please, feel free to ask additional questions. But a HUD was granted to this sponsor for a specific set of criteria, so that they could then go on applying for the HDE, which we have under discussion today at this Panel.
In essence, the indication approved under HUD and now comprises this HDE is for an important niche population that is transplant ineligible, bi-ventricular failure and is a destination therapy population. Dr. Swain and the sponsor also pointed out other indications that the sponsor might be interested in. They might be very important indications for this device. However, they are not covered under the original HUD designation and can't be considered in this HDE.
Hence, while there were some interesting thoughts expressed about some of these indications, we have no ability at this Advisory Panel to make an approval recommendation for those indications that are outside the box.
CHAIRMAN MAISEL: Any other questions for FDA? Yes, Tom?
DR. VASSILIADES: I would like to ask Dr. Swain a couple of questions about her interpretation of the clinical data, because there seems to be some contradiction in even just 14 patients what the outcomes were. One was the sponsor says that two patients were discharged from the hospital and in your presentation, you said one.
DR. SWAIN: Discharged home.
DR. VASSILIADES: Discharged home.
DR. SWAIN: One patient was discharged to a hotel next to the hospital. Because of the electrical environment, the home was not adequate.
DR. VASSILIADES: Okay.
DR. SWAIN: So it was not truly discharged home.
DR. VASSILIADES: Okay. And then the other, and I'm sure we're going to discuss this at length, is the neurologic complications. I'm trying to understand out of these 14 patients what exactly happened with these people.
12 survived the operation, so two expired early on. Of the remaining 12, it appears that seven sustained a fatal neurologic event. Is that correct? And then of the remaining five, there were three which sustained some neurologic, documented neurologic problem.
DR. SWAIN: Right.
DR. VASSILIADES: Such that there were just two patients out of the remaining cohort that did not have any documented neurologic problem.
DR. SWAIN: That is my interpretation of the data by going through the patient summaries that were given to us.
DR. VASSILIADES: Okay.
DR. SWAIN: We didn't have neurology reports on these patients.
DR. VASSILIADES: Right.
DR. SWAIN: Things like that.
DR. VASSILIADES: Okay. And then one last question was in your review of all the records, did you see evidence that the anti-platelet or anticoagulation protocol had been modified from the Patient 1 to Patient 14?
DR. SWAIN: I have exactly the same records as you have in your Panel Pack.
DR. VASSILIADES: But you have spent a lot more time looking at this.
DR. SWAIN: Yes.
DR. VASSILIADES: That's why I'm --
DR. SWAIN: I read them all. There is not enough information.
DR. VASSILIADES: -- valuing your judgment. That's all.
DR. SWAIN: Yes. There's not enough information to answer that.
DR. VASSILIADES: Yes.
DR. SWAIN: We didn't have anything additional than what you were provided in your Panel Pack.
DR. VASSILIADES: Okay. Well, we'll address the sponsor as well. Thank you.
CHAIRMAN MAISEL: Judah?
DR. WEINBERGER: I guess this can be answered by either of you. The patient who had migration of his device and bearing failure, was that addressed by changing the bearing or by changing the issue of migration and what do we know about the biology of migration of devices?
MR. CHEN: I don't think I quite understand what you're asking. Can you repeat it?
DR. WEINBERGER: Okay. You said that there were two failures of the device. One was due to membrane failure and one was due to a bearing failure. The bearing failure occurred in a device where the device migrated in the chest and was placed in unusual operating circumstances. At least that was my reading of the Panel Pack.
MR. CHEN: Correct.
DR. WEINBERGER: My question is is the repair of that problem just a change in the bearing specifications or is it a change in something about the device, which will prevent it from migrating in the future? What do we know about migration as a problem with this device?
MR. CHEN: My understanding of this, and the sponsor can correct me in their response, is that there is an energy converter that is inside the pump and when the pump is placed in the not appropriate placement position, the energy converter has an issue with the motion of back and forth.
DR. WEINBERGER: I don't want to be rude, but I just want to understand. Is this an engineering fix on the technicalities of the bearing or is this an address of the biological issue of migration of the device?
MR. CHEN: It was an engineering fix.
DR. WEINBERGER: All right. So do we know anything at all about the migration of this device in vivo other than this one patient?
MR. CHEN: I have not heard of migration of the device inside a patient, but I think the sponsor will be more inclined to give information about that.
CHAIRMAN MAISEL: Okay. Let's just finish up with all the FDA questions and then we'll give the sponsor a chance to respond to all of these issues. Dr. Nelson?
DR. NELSON: Just a clarification on the indication question. It's my interpretation within the humanitarian use device that there could be a narrowing down of indications if it was felt that that would provide an appropriate balance of reasonable risk, probable benefit, I mean, if it was to address, for example, some of these neurological complications, which we may then end up discussing, but I just want to make sure that's a question that is in bounds as opposed to the broadening of indications, which would be out of bounds.
DR. ZUCKERMAN: That is a generally correct interpretation.
CHAIRMAN MAISEL: Any other FDA questions? So at this point, we can open up the discussion to both FDA and sponsor questions. Why don't we have the sponsor first respond to a couple of the things that the Panel brought up, specifically the use of the device in small stature people, including women.
If you could clarify the device. I'm sorry. We have to keep that middle table free. Clarify what actual device you are planning on bringing to market, whether it's precisely the one that was used in the clinical trial and, if so, which one and answer Dr. Weinberger's question regarding device migration.
DR. KUNG: Let me try to summarize a little bit and then I will let Dr. Dowling get into the details of some of these questions.
As far as the fit from the female point of view, we had taken quite a number of CT scans from, you know, actually before the trial and came to an estimate of, you know, what percentage of females that could fit and it turned out to be something around 15 percent, and that reflects to the fact that we didn't have any, you know, females.
We did actually have a couple of females that went through the screening process and there were, if I remember, one of them that actually fit, but later on decided not to go into the trial and that is the simple question to that.
Now, how do you want to do this? We have a number of questions, I think one of which let me
let --
CHAIRMAN MAISEL: So maybe if we could -- if I can interrupt just for a second. I just would like to try to get through the two or three questions that the Panel specifically asked. So the other one was Dr. Krucoff's question regarding which device will actually be marketed. There were several iterations of the device that were in the 14 patients.
DR. KUNG: Okay. Where is the device? This part of the device, this part of the device is basically going to be the same, okay, basically. The cuffs, we have made modifications and that is the modification that we'll talk about, that we talked about in the presentation and I think Dr. Dowling actually prepared something that we would like to show you later.
I will let him talk to about exactly, you know, what the details of this is, because I think a number of questions came up and, you know, clearly, in that simple presentation, it didn't get into enough details to be really appreciated what we did. So he is going to go into that. We're going to get into that part.
So the change really primarily is in the design of the or the change in the cuff part of it, which is the part that interacts or that gets next most to the tissue. This part of it really didn't change that much at all.
CHAIRMAN MAISEL: So the device --
DR. KUNG: Configuration-wise and so forth, yes.
CHAIRMAN MAISEL: Just to clarify. So the device that would be marketed would be the device that was implanted in the last several patients of the 14?
DR. KUNG: Well, there are the issues, for example, regarding the membrane wear. Okay. We have incorporated, we are going to incorporate some actually minor changes that is going to -- we are pretty sure it's going to help extend the life of the wear.
Now, Dr. Dowling I think earlier on explained why we ended up with a wear, which is the touching of the membrane onto the drive unit, and by slightly changing, for example, the filling volume in there, but still within pretty much our current specification, you can reduce the chance of that membrane touching the energy converter. So that is something that is simple that can extend. So there are those minor changes that's going to try to improve the duration of the system. Okay.
CHAIRMAN MAISEL: And then if you could just answer Dr. Weinberger's question regarding the device migration issue.
DR. KUNG: For migration, yes. Actually, that is not really a migration issue. It turns out in this particular patient, we do a fit. We do a fit and then remember that this device has a fixed distance, an orientation between the left and the right side. And we know that in, you know, normal anatomy that the distance and the cranial and caudal distance between the left and right atria, they are not the same for every patient. But because of the cuff, there is enough, we'll call it sloppiness, compliance or whatever, that that is really generally not an issue.
In this particular patient, there was a substantial difference compared to the average between the left atrial and the right atrial annulus distance, and in the fitting we did not discover that, so the device ended up sitting in an orientation, which is totally unexpected. That was the reason. Okay.
And we did end up with an appropriate corrective action to that, is that based on the CTs and one of the things that we are going to be monitoring and measuring, which is going to be part of the CRF, is that distance. And then based on that, we'll make a recommendation on you can make that adjustment by the trimming of the cuff. So the migration was not the reason for it.
CHAIRMAN MAISEL: Okay. So then you have changed your software to allow the surgeon to know ahead of time before he gets in.
DR. KUNG: Right.
CHAIRMAN MAISEL: That this will not fit within your specification range?
DR. KUNG: Right, right.
CHAIRMAN MAISEL: And that has been validated by the FDA, right?
DR. KUNG: And you have to be -- well, yes, the FDA actually accepted that.
CHAIRMAN MAISEL: Okay.
DR. KUNG: Accepted that problem. The software change there has to do with the fact that for that particular patient, we ran the system, you know, actually outside of what the test range were. So now, the system, the software change, is to prevent anybody from dialing it to outside that range. That's implemented.
CHAIRMAN MAISEL: Yes, sir?
DR. BLACKSTONE: Two comments while you're there about the same thing.
DR. KUNG: Yes.
DR. BLACKSTONE: You have emphasized that what you have changed or is being played with is the interface between the atria and the device. I did not hear whether or not, because these atria are large, whether in any of the cases you're actually reducing the size of the atria, clipping off the left atrial appendage or any manipulation of the atria to perhaps also decrease the clots.
DR. KUNG: The clots. I will let you answer.
DR. DOWLING: Thank you. Rob Dowling again. That is an excellent question, Dr. Blackstone. Maybe before I get back to that, because I do want to expand on that, I can address some of the questions that came up, perhaps clinically related, that the FDA and Dr. Kung weren't able to answer. In terms of the animal models --
CHAIRMAN MAISEL: Excuse me just for a minute. We have to keep the middle table free, so that the Panel can question both sides. Sorry. Thank you.
DR. DOWLING: In terms of the animal models, all these animals, we did 44 animal implants at the University of Louisville and I think they did over 70 at Texas Heart. We did a full autopsy on these animals, including photographs of all the specimens. And when we went back and we developed -- the humans developed clots on these struts, we went back and looked at the pictures in the cow and did not see this phenomenon. So in that regard, we did not think animal studies would be of further importance.
When we identified that there was a problem with the atrial struts in humans, the question immediately came up. Well, why are they there to begin with? And the reason they are there to begin with is because we put these in normal cows and they have a very small atrial volume and it is an active filling device.
So if you start with a small atrial volume and the device actively fills, you will get entrainment of the atria, as Dr. Blackstone was just saying, and potentially inflow occlusion of the device. So the cages were put on for the cows without reason. And then a question came up. Well, do we need those in humans that have a large atrial volume, very different anatomy? So what we did is we went to the animal lab.
CHAIRMAN MAISEL: Can you speak a little more into the microphone?
DR. DOWLING: Yes.
CHAIRMAN MAISEL: It's a little difficult to hear you.
DR. DOWLING: Do you have those slides ready? We went to the animal lab and we actually did studies to determine, as best we could, on an animal model if we could remove the atrial struts without having a problem with the inflow.
Now, we did find out with the modification of the surgical techniques, which we'll be happy to discuss if you like, that it was possible to decrease the mobility of the atria to the point where they didn't cause inflow limiting in the animal model by ligation of the atrial appendage. Another thing we did, we put teflon patches on the mobile parts of the atrium, both the left and right atrium, and attached them with cryoglue, which dramatically decreased their mobility.
So to try to initially attempt to address the problems with stroke in the early patients, yes, we did go back and do animal implants to see if it was possible to remove the atrial struts and not have the problem with inflow occlusion from the mobile aspects of the atrium. And based on that, we did the next series of patients without the atrial struts and with the techniques we talked about, ligation of the atrial appendage and placement of teflon patches on the mobile part of both the left and right atrium.
So it's kind of summarized on this slide. Initial stroke seemed to be related to thrombus on the atrial struts, not really able to see clinically, they are often quite easy to see on echo cardiography. And again, we were not surprised in autopsy to find the thrombus on the atrial struts, because we had seen them on the echo cardiography and it correlated with the presence of stroke in these patients.
One thing we did find was that there's four struts, if you will, and it was only the struts that were in contact with atrial tissue that developed thrombus. So the options were redesign those struts or removal of the struts. Since the struts hadn't been a problem in the cows, we didn't pay hardly any attention to them other than make sure they precluded the animals from having inflow occlusion. They were very high profile, came up quite high and, you know, that was part of the problem.
So the animal studies, as I mentioned, were performed without the struts, with modification of the operative techniques, which I have addressed. The atrial struts were removed for the next series of clinical implants, but the patients seemed to have intermittent problems with the device filling even with those modifications in techniques.
So we thought well, let's go back and look at the struts, which we were doing from the start, and see if we can modify these and make them to the point where they are not going to come into contact with atrial tissue and there's a number of ways you can do that. The first is you can decrease the height of the atrial struts dramatically, which was done. You can decrease the angle, so that they are coming more like a dome than a big old hill.
And the other thing you can do is you can redesign the atrial cuff itself. The atrial cuff initially was flat and it allowed the atrium to come in, so the atrial cuff itself was made more cone-like. So if you can imagine a flat cuff with high struts, which is a very conical cage with very low struts designed to preclude the atrial tissue from coming in contact with that. So as we have in the slide, the most recent implants were done with redesigned struts that do not allow contact with atrial tissue.
Another thing that you have to keep in mind when you're doing the operation is, you know, is it going to be ever possible to completely preclude these animals or the people from having contact with atrial tissue. So yes, Dr. Blackstone, we do ligate the left atrial appendage. We do ligate the right atrial appendage. We have had cases where the right atrial tissue was redundant and we placated it to decrease the mobility of the right atrium.
So an answer to another one of the questions maybe more directly, it's the same device with some software modifications and a heck of a whole lot of modifications in the operative techniques and modifications not so much in the device, unless Dr. Kung would disagree, but in how we sew this in and the design of the atrial cuff. Yes?
DR. BLACKSTONE: So could we agree then among ourselves that we will not use the term "minor changes" or "minor modifications," which is what Dr. Kung was just saying, because it sounds to me like these are important changes. We don't know the results of those and I have no idea what the word "minor" may mean. Let's just say that there are changes or modifications.
DR. DOWLING: I would agree with changes. That's like, you know, people saying -- you know, to me there is no such thing as minor surgery.
DR. KUNG: If I may just add, you are absolutely right that it's important changes. The minor is from the engineering point of view. In other words, to implement that was very straightforward. That's what is meant by the minor, and I apologize if that's misunderstood.
DR. DOWLING: If I could follow-up with Dr. Weinberger. You asked about the migration. I do not think this represents a migration of the device. I think it actually represented the device. You don't get to pick where you put the device. We sew it in and then, you know, we have to kind of sit back and it just kind of falls into the chest of that particular person, wherever it's going to sit.
So I think it was -- actually it sat different in the chest than we had anticipated based on the previous 12 patients, but we have not seen any evidence at autopsy or X-ray, radiographic or clinical evidence of migration of the device. The device, unlike a lot of LVADs, at least the positron pump, itself it does not move. So if it was sitting on the table here, it just shuttles, so I don't think that is an issue.
And there was a question about changes in anticoagulation, which I felt were very relevant. You know, we started this in 2001 and that is four years ago. There's a lot of changes in what we know about anticoagulation. There's a lot of patients that have been shown to be Plavix resistant and so forth. So when we initially started doing this, we were kind of doing a standard.
We were looking at I&Rs and putting patients on aspirin. We have evolved to very aggressive anticoagulation. We get daily thromboelastograms not only on our AbioCor patients, but on all our patients that are on axial flow pumps and require anticoagulation. We look at daily assessments at least in the early weeks after surgery, daily assessments of platelet aggregation studies as another way, additionally, for the tag to look at platelet function.
We also get weekly, what we call complete tags, where we look at whether the patients have developed resistance to Plavix by adding ADP, resistance to aspirin and so forth. So our approach to the anticoagulation has evolved very, very significantly.
CHAIRMAN MAISEL: If I could interrupt?
DR. DOWLING: Sure.
CHAIRMAN MAISEL: I would like to give the Panel Members a chance to ask some additional questions. Dr. Nelson, please.
DR. NELSON: Well, my question, I think, will take us into a little more of a nontechnical area. This particular trial was marked by what may be unique, which was an independent group of subject advocates and we're hearing from investigators, we're hearing from families. I'm curious to know why, at least, the anecdotal impressions of that group are not represented in what may well be a very difficult judgment of incommensurable risks and benefits alike.
Was there any attempt to collate that experience and to see what this independent group felt about the quality of life of the people that were within this trial?
DR. DOWLING: Well, this was unique and, as Dr. Swain said, one of the reasons we are here is because it was high profile and that's one of the reasons that we actually instituted that. And it wasn't just an independent person at each center, but it's actually a group and there was a leader of the group. I do not know if she has collated that and looked at all that information independently. At least I do not think that -- I do not think of asking some of those people to come here and discuss their impression.
Clinically, some families and some patients loved it and some families didn't really want to have much interaction and it kind of faded over time. I think that will be a good thing to look at it, but as far as I know, we can only cut it in a systematic fashion toward the end or at the end of the trial.
CHAIRMAN MAISEL: Dr. Somberg?
DR. DELGADO: I'm sorry, can I just make one comment to your last question? As a cardiologist on the -- taking part in the trial, I was not involved in the implant procedure. I was involved in choosing the patients who could -- who were to be screened for the procedure. And some of these patients have been patients I had followed for months or years and knew the family, knew the patients well. There is a tremendous difficulty going into this, because you have to approach these patients and their families with a total unknown, in this case.
But it was somewhat easy in the fact that I felt comfortable in my mind that I was offering an option to patients who had no other options. And we do a lot of that at our centers, so we have a lot of experience and capability in doing LVADs in very sick patients, and these were patients who were too sick for LVADs.
And so the way I presented it to them was that we have run out of options for you. And here is a total unknown option. And then I turned it over to the advocate. And the advocate, their purpose was to be a totally independent view. One was a physician, one had some philosophy background, they had different backgrounds, but they were -- the physician was actually a urologist, had nothing to do with cardiology or cardiovascular.
And their purpose was to provide the patients and the families with a totally independent view. In fact, they would go to the families without me being there. So there would be a separate meeting with the families and the patients. And one other point of importance is that there were not acute patients done in this study. We would have liked to have done acute patients, i.e., massive acute MIs, but we couldn't, because of that reason, because it was very important because this was such an unknown, to get consent from the patient.
And in the acute MIs and such, most of those patients would be on ventilators or be unconscious or could not give consent. So that's why we had acute on chronics that we treated with this study. And that again is a patient population that is more prone to multi-organ failure.
CHAIRMAN MAISEL: Thank you. Dr. Somberg?
DR. SOMBERG: It seems that the stroke and bleeding are the major limitations of the potential benefit of the device. And with that said, I have heard a lot of emphasis on changing surgical technique and maybe some engineering aspects, which may or may not, those thrombi that were forming in the intake strut, relate to the embolization problem, etcetera. I'm not sure if, you know, the timing has been carefully analyzed, etcetera.
With all that said, I would be more reassured if the sponsor could talk to us a little about their systematic approach to further development of an anticoagulation protocol and involving specialists in anticoagulation, because it sounds like you have gone to a certain progress or progression of a device development, but you have been stymied by this problem and it may come from areas that haven't been thoroughly investigated or systematically dealt with.
I mean, I just noticed their arbitrary -- when is platelet therapy given, 100,000 platelets come, there are some arbitrary numbers thrown out here. I'm always worried about medicine when we do arbitrary things or we do things as we have done in the past. We should investigate it. And while we are asked to give a safety probable benefit balance here, it seems to be an experimenting progress and not to have had this aspect worries me that it hasn't been dealt with. But maybe it has and I would like to hear from the sponsor if you could.
DR. DELGADO: Let me just make a point on that, because one of the things that was decided very early on in this study is that the sponsor would not, them not being medical doctors, involve themselves to a great degree into the medical management of the patients and that they would give us, those taking care of the patients, the ability to have some leeway in that.
Having said that, us, the clinical doctors, Dr. Dowling and myself, Dr. Frazier and others got together and developed our own protocols that we use. In our case, it was a protocol that we adapted from use of an LVAD device. These were protocols that were institutional specific. Now, Dr. Dowling's group had a similar protocol that was institutional specific to them, but there were protocols. Basically, they were just our own internal institutional specific ones with some modifications based on collaborations with the other institution.
We also did involve hematologists in the case of these patients. They followed them on a daily basis for the first week or two. And because there is such an unknown here, we also used this thromboelastogram, which is a sensitive way of following anticoagulation for multiple aspects, anti-thrombin affect, anticoagulant, anti-platelet affect, and we learned a lot over time.
Our biggest limitation was if they had bleeding, either surgical bleeding or other bleeding, then we had to back off anticoagulation and did, at that point then, start to see strokes. As to where the strokes came from, and I think there is some evidence that, in my mind at least, they did, a large proportion of them came from that strut system, because we were able to do transesophageal echocardiograms and visualize the left atrium and the inflow to the strut and we were able to see clots there in vivo and in living patients.
And so that's where that belief came from. Now, is it possible that came from other sources? Yes. In fact, in one patient I do believe it was an insight to thrombosis of an intracranial vessel. So we don't know. But a lot needs to be learned. There are new anticoagulants coming on board, direct thrombin inhibitors, for example, drugs that are oral that can be more evenly managed than Coumadin. So it's a work in progress.
DR. SOMBERG: Well, what I'm really getting at, if I may ask just this follow-up question, is since you have now identified a problem after the 14 patients that is of major concern and that does limit considerations, in my mind, considerably, it probably behooves the sponsor to seek and organize. And if they haven't done it, you know, I would ask would they.
And they don't have to answer this moment, but it would help this Committee Member if there was an organized program to try to deal with this to try to increase the probable benefit and decrease the safety issues and not leave it to an institution specific. Because each group does so few of these things, it is hard to develop a systematic approach.
DR. DOWLING: Robert Dowling, Dr. Somberg, if I could address that. We have spent a huge amount of time on that and emailing protocols back and forth. You saw that this will be, if approved, introduced at a limited number of centers. One of the criteria will be, one, you have the ability to do a thromboelastography and, two, that you have a hematologist involved as an integral part of the team.
We spent a lot of time talking with a number of centers, with a number of people that have published in this field extensively, Dr. Nolan at the University of Arizona, with Dr. Copeland's team. We kind of gave a little bit of the overview of how our anticoagulants and protocol has changed. And I would be more than happy to amplify it, if you would like.
For instance, what we found at Texas Heart and the other centers, we're all in agreement that the traditional thought of starting heparin anticoagulation within 24 hours led to a high bleeding rate. And we independently came to the conclusion with Dr. Delgado, Dr. Gray, of course, and myself that this was too early to start heparin in this group of patients.
So now our recommendation is to wait at least 48 hours before starting heparin and then consider not starting heparin unless you have a platelet count above 100,000. Because we went and looked back at our data, not only in these patients, but in our larger population of LVAD patients that required heparin, those were the patients that seemed to get problems, early starting of heparin anticoagulation associated with low platelet count.
So now what we do is, beginning on the first day of surgery, we look at all these traditional things, platelet count, PT, INRB, also get a thromboelastography. If the platelet count is about 100,000 and your MA is in the normal range, we would start anti-platelet therapy. So one of our main goals to kind of be succinct is to achieve a normal MA on the thromboelastogram, which is a measure of platelet function.
And if we start aspirin, we expect the MA to come down to within the normal range, if it's outside the normal range. If it's not, we have very defined thoughts, I'm sure Texas Heart does, too, and the other centers will, about what to do next. We would start an 81 mg aspirin a day. If the MA didn't come down, we would double it. If it did not respond after, we would probably give 150 mg load of Plavix and start them on 70 mg of Plavix a day or use Persantium, but there is a discussion among the teams whether that adds much or not.
One good thing about it is you stop it and it goes away. So we have very specific thoughts about when to start the anticoagulation. We differ a little bit in some of the centers in terms of how long we want to keep patients on heparin. We like to have the patients on heparin a little bit longer, because they might need central lines or chest tubes, but as soon as we think that the patient is not likely to need any other even minimally evasive procedures, we switch to Coumadin.
Texas Heart, I think, switches a little bit earlier and Dr. Delgado can correct me if I'm wrong. But we look at these platelet aggregations. Even if our MA is normal, but our platelet aggregation is above 65 percent, we would add additional anti-platelet therapy. We would increase our aspirin or increase or Plavix. We would get a full thromboelastography to see if has this patient developed resistance to Plavix. And we have seen that and we have had to go up, we have had patients on 150 mg of Plavix a day, not uncommonly to maintain a normal MA on the thromboelastography.
DR. SOMBERG: I don't want to belabor this, but I hear you and what you have done and it's really remarkable. But unfortunately, you have this seven or eight or nine incidents out of the 14 or 12 that survived of these CVA problems, etcetera, and I'm just saying this needs to be something systematically done on top of that. That was just my suggestion.
DR. DOWLING: Yes.
DR. KUNG: If I may just say something? I think you are really suggesting that as we go forward there should be, you know, if we go into the post-market, there should be a team put together that discusses how the somewhat of a common protocol and I think that's a great suggestion. We, I think, had some details written in the Panel pack in terms of the protocol, but I think again, it needs to be coordinated amongst the centers. I think is really what you are saying.
DR. SOMBERG: Right.
DR. KUNG: I agree.
CHAIRMAN MAISEL: I mean, I think there are two issues. One is the instructions for use for a center, meaning there needs to be some specific protocol and, two, would be certainly trying to move forward and we do see the stroke risk. Mitch?
DR. KRUCOFF: I just have a quick question on my understanding from what I see in Patient No. 2, who is the individual who had a device long enough to have membrane failure issues was offered an opportunity for reoperation and declined. Do we know why that patient declined? Can you fill us in?
DR. GRAY: Yes, there was a long discussion with the patient and the family, and he had just started to get older. He was what 75 at the time when it went out and the decision was just made that he didn't want to undergo it. It was just his decision. And I really want to make one other comment, too, about the strokes.
If you look at the patients that had the strokes, the large majority of them had the strokes because they were having bleeding problems. Now, this goes back to the anticoagulation thing and I agree 100 percent. But if you look at the first patient, Mr. Tools, Mr. Tools had multiple bleeding problems and he had GI bleeding. It's very interesting and he had more endoscopies than anybody in the world. And they go in and cauterize, punctate lesions in the stomach. He had bleeding multiple things. He then stroked after he had been off all anticoagulation for about a month or two.
Another patient that had a stroke, again, he had done extraordinarily well. He was actually ambulating in the hospital. He developed diverticulosis, okay, and colon problems. The bleeding from the diverticulosis was severe enough because of the anticoagulation, we had to take him off of anticoagulation, he was off anticoagulation in excess of two months before he ever had a stroke. Everyone knows anybody with double valves is going to have a problem.
DR. KRUCOFF: Okay. Can I just stick to my question for a second, because I think we have seen in a number of very successful, ultimately successful technologies for patients who are literally under death's threat that after an initial sort of surge of joy, etcetera, what follows is the lifestyle and what comes with it and depression and longer term wishes to turn it off or take it out or certainly not replace it.
So I guess what I'm really trying to ask is in the one individual who lived long enough to have a device failure, who was offered an opportunity to revise the device.
DR. KUNG: Dr. Krucoff, may I ask one of the family members, because they were, obviously, involved in that decision. So do you mind one of the family member answering?
CHAIRMAN MAISEL: Is that okay, Geretta, for one of the public speakers to speak, at this time? Okay. That's fine. So specifically, if you could address Dr. Krucoff's answer -- question as to why.
MS. TOOLS: It was very important from the very beginning that the whole family was included on the decisionmaking to receive the device in the first place. Dad called everyone in down to the grandchildren and everyone was to have a vote. We tricked him. We let him vote first. And when it came time to decide whether he wanted to have the heart replaced, he looked at all the options. The initial surgery is very serious and it takes a few months to get over that.
Dad knew that he had had such a wonderful experience with that first time that he really did not want to chance the failure the second time or perhaps not being able to recover from the surgery. His health was good, but he just did not want to put us in the position of possibly not having such good results. He said he had that faith in it once and he just didn't want to mess up a good thing.
CHAIRMAN MAISEL: Okay. Thank you. That's very helpful. Any others? Joanne?
DR. LINDENFELD: A couple of questions. The device is said to be for people who need right ventricular support. And just in going through the patients, if I might, I wondered if there were standard criteria for what would constitute a patient who needed RV support? For instance, let me just, as I quickly look through the individual patients, Patient No. 2 had a wedge of 18 and a CVP of 2. Normally, we wouldn't consider that that patient would need RV support.
There are a couple that are more questionable. 5 was 25 and 8. And just going through them, I counted up seven out of the 14 who, I think, had wedge pressures that were substantially higher CVPs that were in the normal range. Out of that seven out of 14, there were another three or four who most people will consider were very probably candidates, based on at least those pressures. We don't have other data.
So I think there were only two or three, based on wedge and right atrial pressures, that everyone would agree were not candidates for an LVAD only. So I'm very concerned that the population alone doesn't really mirror who you are asking it to be approved for, that is at least half of these patients, in my view, in most institutions would be candidates for LVAD only.
So based on the pressures we have, now, admittedly, I don't have all the data here, but going through each case individually and I would be happy to do that, because I wrote all the pressures down.
DR. DOWLING: I would agree that usually right side of filling pressures are indicative of adequate RV function. We spent a very significant amount of time looking at patients' RV function. I think, I don't know this for a fact, but just my clinical impression was that the number one reason that patients got excluded from the trial was because they were not in bi-ventricular failure. They all had a left sided heart attack and the RV was functioning well.
I learned a lot more about RV failure during this trial than I ever thought that I would need to know. And one thing that we found is that if you take a patient and put him on a balloon pump and put him on Natrecor and multiple inotropes, maybe even put him on inhaled pulmonary vasodilating agents that it is not uncommon to be able to get their filling pressures to the very low numbers that you saw, even though you have -- they have a history of heart failure, you have an echo that the right ventricle looks like it's not even moving.
The first patient, for instance, we recorded, and the CRF data, there was only one datapoint, so when Mr. Tools had his surgery, we took him to surgery asleep. At surgery his CVP was 34. If you look at what his number is in there, I think, it's a single digit number and his RV function was not moving. That's why Bob Kung, Dr. Kung was talking earlier about looking at atrial volumes.
If you look in the literature, you can't find a paper that says these are the three -- you know, you need four -- three of these four parameters.
DR. LINDENFELD: No, excuse me. You can find some papers that suggest parameters. And I would say there is at least seven patients in here who would fit clearly into the LVAD category by several published parameters.
DR. DOWLING: Well, you can find papers, and for instance, right ventricular work index is one of those parameters. We didn't look at that, but I don't think you can find any where a paper that would suggest you just look at filling pressures. What we were trying to suggest was that we needed to look at a combination of their clinical history of right side heart failure or the clinical exam, echo assessment. Filling pressures was on that list. We agree with you completely about that.
But when we looked at these patients and looked at all those parameters, our clinical impression, and a lot of it was based on echocardiographic evidence of RV function, was that they did have significant bi-ventricular failure. These were not patients and again like Dr. Delgado, we have a busy LVAD center, this is not patients that we would have considered acceptable, LVAD only patients.
CHAIRMAN MAISEL: Norm?
DR. DELGADO: Let me just say that we absolutely completely excluded LVAD as an option in all the patients we enrolled in this trial for various reasons. It is very hard to determine right ventricular function with a snapshot in time. It's very, very hard. All of these patients just prior to implant of the AbiCor were maximally medically managed dramatically. I mean, multiple drips, balloon pumps, inhaled nitric oxide, all kinds of things.
And one patient, in particular, had a high PVR, it's 7 units PVR, so you couldn't get an LVAD for that reason. So it's multiple reasons, but they were not LVAD candidates.
CHAIRMAN MAISEL: Thanks. Joanne? I'm sorry, continue.
DR. LINDENFELD: Okay. I just wondered if there was a specific criteria for antitrope weaning? I mean, was there some definition of ability to wean inotropes?
DR. DELGADO: Oh, inability to wean from the inotropes? These were patients who were in pending -- who were either in the midst of going into organ failure or in pending organ failure despite inotropes. Very, very sick population. So these are unweanable, most of them on balloon pumps.
DR. LINDENFELD: But were there any specific criteria for unweanable?
DR. DELGADO: Not that I know of.
DR. LINDENFELD: Okay.
DR. DELGADO: Yes, not that I know of. A lot of this becomes the judgment of those managing the patients.
DR. LINDENFELD: Yes, I understand these are very difficult things.
DR. DELGADO: Unfortunately, it's a difficult heterogenous population.
DR. LINDENFELD: I appreciate some of those parameters. Let me just then ask, this issue of strokes is a really important issue. And I want to go back. We talked about what the mean or at least we were given the mean and median time to death. But can you give us an idea of the mean and median time to neurologic, irreversible neurologic disability?
Many of these patients lived days and in some cases months beyond what most of us would consider irreversible neurologic deficit. Can you give us some idea? My rough calculation, and it's very rough, would be 88 days is the mean time to severe neurologic dysfunction incompatible with any sort of reasonable functioning. It's substantially shorter than the life expectancy.
For instance, one patient who lived 57 days, but never recovered neurologic function. We were told that a number of other patients lived on many days after they had a stroke that was irreversible. So can you give us just some idea of what the time to irreversible neurologic dysfunction is?
DR. DELGADO: We actually reviewed that question during the break. And we did find that there was one patient, as you mentioned, who had a prolonged time period between irreversible known as the function and the withdrawal of support.
DR. LINDENFELD: There was more than one patient. No. 12, for instance, I think only had 17 days with reasonable neurologic function, but lived 86 days. Patient No. 11 had fairly irreversible neurologic dysfunction at day 56, it sounds like, but lived 115 days. Patient 9, you are referring to, had no recoverable neurologic function, but lived 53 days. Patient 14 had severe neurologic deficit at day 132 and lived another 32 days.
And I think these are important issues. It's not just how long do they live. But I think we would all agree that if you have, essentially, no neurologic function, that's not -- we need to consider that in terms of the --
DR. DELGADO: Right.
DR. DOWLING: We did look at these in detail. For instance, the Patient No. 9, who lived 53 days, he was very slow to wake up neurologically from his operative therapy.
DR. LINDENFELD: The report says he never actually regained any sort of -- is that not correct?
DR. DOWLING: Well, I don't -- I would have to look at the report to see the exact wording.
DR. LINDENFELD: I mean, in Patient No. 12, the differential is 17 versus 86. Patient 11, 56 versus 115.
DR. DOWLING: Yes.
DR. LINDENFELD: I mean, again, this really substantiates -- this is just a safety issue. What do I tell people about what the safety is and, you know, there is a big difference here between survival and survival with some sort of reasonable neurologic function.
DR. DOWLING: Yes. I would say that there was never -- the patient we talked about, for instance, he did show some signs of neurologic recovery to the point where the family was not able to -- willing to withdraw support in the early post-operative period.
DR. LINDENFELD: I just want to come back to this, because, again, I'm trying to understand this. I understand these are very difficult patients. But, for instance, Patient No. 2 that was discharged home. It says in your summary that on day 188 he began to lose short-term memory, became harassable, irritable at home and that that gradually progressed. Now, that's 188 days versus 515 total.
It might not have been irreversible neurologic function, but loss of short-term memory and irritability certainly affects quality of life. And since we don't have quality of life measurements, I mean, I would be pretty concerned if people live a lot longer, but don't have enough neurologic function to have any quality of life. Since we don't have quality of life measurements, I'm just trying to understand that. It seems like there is a huge gap in a number of these patients.
DR. DOWLING: Well, the second patient you are talking about, you just heard from his daughter.
DR. LINDENFELD: Well, I can read directly from your report.
DR. DOWLING: Yes, no, he did.
DR. LINDENFELD: It says on day 188 shortly after discharge from the hospital.
DR. DOWLING: Right.
DR. LINDENFELD: I think the same day. He began to lose short-term memory, became irritable, had to be treated for those kinds of things.
DR. DOWLING: Right. That is correct. There is varying degrees. He had a mild, sometimes more than a little bit mild problems with short-term memory, but he was still completely functional. You just heard from Patti that --
DR. LINDENFELD: Well, I don't know that. I'm sorry, I don't mean to be argumentative, although it's sort of my job. I mean, I don't think you can say someone is completely functional when they don't have short-term memory. At least, if I can't remember how to get to the airplane today, I'm going to have a hard time being functional.
DR. DOWLING: No, if I could just complete my thought, is that he was able to function. This man was able to function, that's what I am telling you. Sometimes he would need assistance, but as you heard from his daughter, that when it came time for him to decide, he called the family in, he made the decision, he was able to function. When he started to develop the short-term memory, we asked him to be seen by an internal medicine physician, who thought that he was demonstrating signs of alzheimers.
In discussion with the family that he probably had some signs of that before the surgery. And so she started him on appropriate drugs for that and it seemed to stabilize that out. But his -- based on his short-term memory problems, he did not have --
DR. LINDENFELD: And his CT scan at the time showed?
DR. DOWLING: He had no CT scan evidence of any thrombotic events during this entire 17 months. And at autopsy he had no evidence of thrombi, so he did not have incidents of micro-infarct dementia, if that's what you're asking. We specifically addressed that with the pathologist and they said no, they did not see that.
DR. DELGADO: A quick comment also is that a number of these patients had hepatic encephalopathy that was transient and one of mine, in particular, had dense encephalopathy due to liver dysfunction that resolved with -- took a long time, but did resolve. Second is in one instance in one of our patients, we were able to acutely thrombolize the patient when he had a clinical stroke, absent of a CT finding. And we were able to achieve complete resolution.
So, you know, perhaps that's a strategy that can be employed in the future to minimize strokes. I mean, my personal feeling on this is that the stroke issue is a big, big issue with these patients and quality of life in the future and the future viability of this device. But I truly do believe we can improve upon it.
CHAIRMAN MAISEL: Thank you. Norm? Oh, you're all set. Dr. Borer?
DR. BORER: I would like you to respond formally to the question that I asked earlier, which is really a subset of the issue Joanne just phrased. Let me put it in context.
As I see it in general, without going into details here, you have taken a population that was either bed bound with severe pulmonary vascular congestion, i.e., drowning, or in a very low flow state, so that they were, essentially, inactive or a combination and you put a device in and, for some period of time, they have regained the capacity to act, to live in a more normal way and, at some point, they are going to lose that capacity again.
We have a list of causes of death here in the book that was sent to us and although it says that 7 out of the 14 deaths were due to stroke, it sounds like that is not entirely correct. But there were events that occurred before these people died, and then they were no longer able to do what they had been able to do with the device.
I would like to know how much time elapsed between that preterminal event and death, so that I can be reassured that these people who are either drowning or unable to act because of low flow weren't put back into that situation for another month or two before they ultimately died. The concept here is the lack of suffering before death.
Was that affected and if so, how?
DR. DELGADO: Just to make sure that there was not any investigator bias in influencing the family, etcetera, in these issues, we employed the use of these patient advocates when those events occurred and they would spend time with the family and talk to them. And again, I truly do believe those patient advocates were totally unbiased and they would, you know, weigh the pluses and minuses of withdrawing support, etcetera, and support was withdrawn in some cases based on those discussions with the families.
As far as how long patients may have been allowed to live with suffering or prolonging of suffering, it becomes a philosophical issue and, you know, not one I guess I or anybody else can really quantitate. Many of them -- in some circumstances, the patients had lost consciousness and then there was a period of time before withdrawal of support. But as far as prolonging suffering, I personally wouldn't allow that to occur to one of my patients if I knew it was occurring.
DR. BORER: Was the death always due to withdrawal of support or were there any spontaneous events like a big stroke that becomes hemorrhagic and there is rupture of the brain stem?
DR. DELGADO: Well, actually, that is a gray area, too, because that did happen. You know, there was a massive stroke in a patient, but then the patient was then pronounced as a result of withdrawal of support. The simple fact with this device is that you can keep anyone alive with this device. I mean, the device gives you vital signs period.
It's a mechanical vital sign maker and so the patient can be brain dead on this device and have normal vital signs. So ultimately, it comes to withdrawing support. And in that case where the patient had an obvious massive stroke, it was just a period of hours until the withdrawal of support was done.
CHAIRMAN MAISEL: Thank you. Dr. Nelson?
DR. DOWLING: If I can just follow-up on that real briefly. I would just echo what Dr. Delgado said. We're clinicians and if we have a patient who is in a situation where they are not able to recover, we would have no reason to continue support.
When I look at this, for instance, one patient, November 29th, a major bleed following a stroke and he died on November 30th. And, as Dr. Delgado said, that means the following day that we talked to the family. We get to know these families. They have become our family. The one patient, the ninth patient that we talked about, did show signs of neurologic recovery. He was moved to the ICU. He was moved to the floor. He did not require any more aggressive nursing care than usual.
So to directly answer that, that patient, yes, he was showing signs of recovery and then, you know, you have to deal with the families. You know, sometimes they want to -- when you're ready to say there's no signs of neurologic recovery, we have all seen it, oh, he smiled.
I mean, you know, there are familiar cases in the media about when to withdraw support. It's a difficult situation, but I don't think any of us have any intent other than to keep these patients alive by artificial means. I wouldn't want that for myself, my family or my patients.
DR. LINDENFELD: I don't think anyone is implying that. We're just trying to figure out how many days. Since there wasn't any estimation of quality of life, we're trying to figure out how many quality days there really were.
DR. DOWLING: I think that's an excellent question and I think if we could try to make a concerted effort to provide you that information before the end of the afternoon, that we should.
CHAIRMAN MAISEL: Thank you. Dr. Nelson.
DR. NELSON: Just one quick comment and then I'll give my question. This last exchange just brought up to me a kind of sticky wicket going forward, because there are both individuals and groups who don't accept either brain death criteria for declaration of death nor withdrawal of support and if you put in this artificial vital sign producer, you could be in a real bind at some point in the future. So just to keep that in mind. I'm not sure there's an easy solution to that, except to anticipate these in a good, informed consent process and conversation.
My question goes back to the clots and to the strokes. I can imagine two different approaches. You appear to be choosing the management approach after surgery, and so my interpretation from that is that you think these complications of bleeding are a function of the surgery itself and the extent of their disease.
Is there any way one could attempt to predict this to where you could actually exclude individuals who would be at higher risk, so that you could then not offer this device to those who, in fact, you think could have it or is this all just the activation of bleeding and difficulty management after surgery and it would be impossible to predict? I mean, which way would you go?
DR. DELGADO: I think that's hitting the nail on the head. This is going to become an evolution of patient selection. I think the patient selection that was done for this initial trial is going to be honed in the future if this device continues to avoid just that, patients with adverse bleeding risk, patients with really bad liver function, for example.
One patient of mine, for example, I clinically felt he might have had cirrhosis of the liver. We did all tests, including a biopsy, which were negative for cirrhosis of the liver. Ultimately, at the end of the day, after all things were said and done, I think he probably did have cirrhosis of the liver and the biopsy just missed it. So patient selection is absolutely key, and I think we have to evolve towards that and we have to evolve towards patients who are lower risk for bleeding complications.
A lot of these patients didn't bleed because of surgical bleeding. A lot of them bled because of something else, GI bleeding from GI AVMs, which we see commonly in the elderly. We see it in LVADs a lot, axial flow LVAD patients. I published a paper on the increased incidence of GI AVM bleeding in axial flow LVAD patients. And so we need to figure out how to select these patients and it's going to take time and evolution.
CHAIRMAN MAISEL: Thank you. At this point, I would like to move on to the primary reviews. We'll have Joanne do hers first, please.
DR. LINDENFELD: First, I just want to say this has been a really wonderful development program. It's an important device and I'm impressed with the development of this device, and I'm also impressed that all the clinical investigators have acted in best faith with this device.
My concerns about this are several. I know we're supposed to determine that the device does not expose patients to unreasonable risk of injury or illness and there is a probable benefit to health, and I don't think this particular data set has met either of those criteria for the following reasons.
But let me start first by saying I'm concerned that the patients, as I review each individual one of the 14 patients, as I said, there are a number of patients in here where I think, by at least most of the standard published guidelines for who could get an LVAD, those patients might fit into there.
So I think that while the individual institutions, I'm sure, have additional data on which they made that decision, I'm not sure how another institution could utilize the data we see here and determine that, and that's a concern for me. I think when I see a wedge pressure of 29 and a CVP of 2, it's hard for me to determine that that patient couldn't have a Left Ventricular Assist Device. So that comes before the issue of safety.
Safety I think is the biggest concern here. We see an enormous incidence of stroke and not just stroke, but death due to stroke, other neurologic deficits. There has been modifications throughout the study, I understand, of anticoagulation, but for the life of me I can't understand what those modifications are.
I see no data about how to use the thromboelastogram. We haven't been presented with that or its predictive value or its ability to either prevent bleeding or to prevent stroke. I'm sure that there's some data there, but we haven't seen any of it and without that data, I can't feel reassured that I could either prevent thrombosis or a stroke. So I think that's a critical missing element here in terms of safety.
I'm also concerned that probable benefit, I see no data in terms of quality of life and as I look at it, as I said earlier, I think the time of just life, even life in the hospital with some sort of realistic neurologic function, is substantially shorter than the duration of life that we see here.
I'm a little bit concerned, although I don't think it would be a reason to not approve this device, I'm a little bit concerned that it's only likely to fit 15 percent of women and I haven't yet heard, and I think we can address this later, how the TET coil will be placed in women, particularly women with large breasts, and whether or not that is considered to be a possibility or if this is just not a device for women.
So in terms of the bleeding, we have stroke as a safety issue and we have bleeding as a safety issue and we are told that the anticoagulation protocol has become more sophisticated over time. But as I sum up the risks of nonsurgical bleeding that occurred after 30 days, there is absolutely no difference as we go from Patient 1 to Patient 14.
Now, I'm certainly willing to see data that would correct me there. But as I look at it, nonsurgical bleeding in the last four patients, there were four, two, two and five episodes respectively of nonsurgical bleeding after 30 days from the time of surgery, and that doesn't look to me any different than the nonsurgical late bleeding early on. So I remain unconvinced that we have settled this issue of how to control bleeding versus stroke.
And that is the primary safety issues for me. In terms of the probable benefit, I have a hard time with this data. I understand that these were incredibly ill patients and I believe that they were very, very sick, but I think for the majority of patients -- and I think we have not even seen how many hospital days, a number. Even in the patient that was discharged, there were a number of readmissions.
So the probable benefit, I think I could only estimate as possible, at this point, without more attention to the bleeding episodes, etcetera. So overall, my review of this is that this does not meet the HDE criteria at this point in time, although I think it could in the future.
CHAIRMAN MAISEL: Thank you, Joanne. Dr. Ferguson is one of our other primary reviewers. Tom?
DR. FERGUSON: I, like Joanne, think that this is a remarkable series. I'm not talking about the number of patients and so forth. I'm talking about the 42 years that have been put in to developing this device, and those of us who have dealt with mechanical devices in the cardiothoracic arena can appreciate all the nuances that have gone into the development of this artificial heart.
Now, I'm going to ask about the strokes also, because we have been told that the strokes have occurred, because these patients are very sick and their livers are bad and they bleed a lot when a device is put in. Cardiac surgeons have been fighting clots and stroke since we have began to put artificial material into circulation 50 years ago and it gets worse and worse the more you put in. Everybody would agree, I think, with that statement.
My question, I guess, is that nobody has been able to solve the stroke problem with LVADs or with any other devices, except perhaps heart valves, to the degree that we would like to see, everybody would like to see, in terms of taking care of the patients. So I would like to be reassured. Number one, question number one. I would like to be reassured that you are totally convinced that the mechanical design of the device and the modifications that have been made for the cuff, for the atria, are all that can be done to minimize the device itself as a clot producer. That's a question.
DR. GRAY: I think the best answer we can come with that is that when you examine the device in all the patients, there is no evidence of any clotting in any internal part of the device involved anywhere. And the only place we found any clotting on the device has been on the inflow cages, but the devices themselves have been totally clean.
It's limited, but with the redesign of the cuff, you look at the cuff and you see very good endotheliazation up and around the struts. The struts have been modified. And in the, granted, limited number, there has been no evidence on the autopsies of any clot forming around those and in those three patients, particularly the entire device and the inflow canula was perfectly clear.
DR. FERGUSON: That approaches the answer I want, Laman, but not quite there, because we're left with a very high stroke incident rate in a small number of patients.
And what I want to know is do you think that the manipulation of the bleeding problem first and then the manipulation and care of the anticoagulation in the future is going to bring the stroke rate down, that is my question, or is it due to the mechanical problems? You don't know where those clots came from in the ones that at least had the water ring put in, correct?
DR. KUNG: Yes. Actually, I stood up because since we are on the topic of strokes, we will get to answer your question, is that we have talked about, you know, five patients died of stroke and so forth, rather than the seven, and I do want to -- we need to clarify something here, because Dr. Marelli is here.
He has got a patient, which was listed on one of your tables, on the FDA tables, as died of stroke and I am not sure. Unless we have misrepresented that information, that patient did not. And I would like Dr. Marelli just to qualify that, because that is really important, because this is an important subject here.
DR. MARELLI: Our patient died on post-op day number 56, withdrawal of support at the request of the family. Our IRB had that built in. He had hepatic encephalopathy with very high total bilirubin level, I recall, close to 50 and renal dysfunction requiring dialysis to clear BUN that was close to a level of 100. The autopsy did not reveal any evidence of stroke and I believe it was a very reliable autopsy and we have the pictures and so on. So I do not recall any event of stroke in that patient. So I'm not sure why it came out as stroke in a review of the data.
If I can make one comment, because it seems to be a persistent issue, regarding right ventricular failure, and it's an issue that you're right, you would be thinking that somebody with a CVP of 2 and a PA systolic pressure of 35 or 40 or 50 would have pure LV dysfunction. And most of us who put in LVADs would go in and say let's just put in an LVAD and things will be fine, but we have been burnt by this scenario. And one of the things that we discover is that when the cardiac output total is only 3 or 4, what happens is when now it becomes 6, the RV cannot handle the load and many of these patients preoperatively, I recall in the AbioScore, there is a criteria of ankle swelling and ascites.
And perhaps a reflection of all the RV dysfunction that the patients have preoperatively is, in fact, the early tendency to bleed, which would reflect coagulopathy tendencies due to liver problems and engorged veins.
So it's very hard to pin that one down in this population, but all the patients had echoes and, you know, we were all involved as a group and I can say, typically, even in patients that we consider for LVAD as a bridge-to-transplant, there are criteria in the surgical literature that say if the RV ejection fraction, if there is such an estimate, is this amount, then chances are you will need an RVAD when you come off. And oftentimes we put in an LVAD, we come off pump and then we see the RV balloon up, because it just can't handle the load. And this has been written about in the literature.
CHAIRMAN MAISEL: Thank you for those comments. I would like to try to let Dr. Ferguson finish his review and get his questions answered.
DR. FERGUSON: Thank you.
DR. KUNG: Do you want the answer now? Your question, do you want the answer now?
DR. FERGUSON: Yes, that one, right.
DR. DOWLING: First, briefly, Dr. Lindenfeld, the TET coil was placed in the infraclavicular area.
CHAIRMAN MAISEL: Can we try to focus on the question that's on the table, please?
DR. DOWLING: Sure. Okay. So, Dr. Ferguson, you were asking if we were convinced that the design changes were adequate, and I think you made a very good point that whatever you put in the vascular system, you're going to have a stroke rate. So the question is is our new anticoagulation protocol and the design changes adequate?
When you see these thrombus on the atrial struts and the patient on echocardiography and at autopsy and you also look at the blood pumps, and they are entirely clean, it's reasonable, I think, to conclude, but not say for a fact, but in likelihood is that the thrombus events occurred from the atrial struts.
So having seen those echoes and having seen those autopsies, I think that the design changes we made in terms of the redesign of the atrial cuff and the struts and all the reasons I explained earlier, are going to adequately address this as well as we can. There is going to be a stroke rate with any device, with any heart valve.
DR. FERGUSON: Sure.
DR. DOWLING: And there are patients, like our last patient who couldn't tolerate being on anticoagulation, who are going to develop stroke, as Dr. Gray said, similar to double valve patients that will develop stroke on anticoagulation. So the short answer to your question is yes, we think we have been very diligent in making these design changes and very diligent in adjusting the anticoagulation protocol to address these issues.
DR. FERGUSON: Well, while you're up there, this is probably not a very fair question, but the design change happened at patient number what for the atrial cuff?
DR. DOWLING: Well, there was actually two. I think after the fifth patient, the atrial cuffs were removed and we did three patients. And I think it was after the 11th patient.
DR. FERGUSON: The 11th patient.
DR. DOWLING: After the 11th patient.
DR. FERGUSON: Okay.
DR. DOWLING: So the 12th.
DR. FERGUSON: My question is I couldn't find any evidence of even a trend in the incidence of the strokes that would either be due to increasing sophistication about the management of the anticoagulant or the design change. In other words, can you say that you have had a decreasing incidence of stroke since Patient 1 through Patient 14?
DR. DOWLING: Well, I would agree with Dr. Swain. The numbers are just too small for me to say that.
DR. FERGUSON: But you haven't seen --
DR. DOWLING: We can say that the 12th and 13th patient had no evidence of thrombus on the atrial struts and no evidence of stroke. The last patient was off anticoagulation for two months time. He also had very extensive carotid disease with 100 percent occlusion of one carotid and mild occlusion of the other carotid, and he did develop a stroke that was not the cause of death, and that was a moderate stroke.
So the direct answer to your question is-- yes, and also he had a pre-op history of stroke which, as you know, increases the likelihood of postoperative stroke. So statistically, can we say that? No. On the other hand, it is my feeling that with the design changes and, you know, more attention to anticoagulant therapy and thromboelastography that it probably will have an impact going forward.
DR. FERGUSON: Thank you. I had a question about the size of the implant, vis-a-vis women, but I understand from something I heard or read that you are developing an instrument that is going to be much smaller in size.
DR. KUNG: We are, but that's actually a number of years down the line. So it's not something that will be available tomorrow.
DR. FERGUSON: No, I understand that.
DR. KUNG: Yes.
DR. FERGUSON: I understand that.
DR. KUNG: Yes. As you know, these development processes or programs --
DR. FERGUSON: Sure.
DR. KUNG: -- they do take a long time.
DR. FERGUSON: I just think that's an important thing to get out on the table, you know, down the line, because that's a huge population that's unserved.
DR. KUNG: Right.
DR. FERGUSON: And I don't think we --
DR. KUNG: And when that time comes, we obviously will, because it will be a larger patient population. It would be something that would be done under, you know, a clinical trial, but it is not something that we have right now. It is under development and it's doing some preclinical testing.
DR. FERGUSON: One other question about the placement of the instrument. This is a technical question for the surgical group. It seems particularly emphasized by the one patient that had the bearing burn-out that the burn-out was due to malfunction of the outflow tracts or inflow, not inflow, outflow tracts and do you want to comment on that?
DR. KUNG: Yes, I do, just for clarification. It's really the relative position of the inflow. Again, these devices have --
DR. FERGUSON: Of the inflow.
DR. KUNG: These devices have fixed or this device has a fixed inflow orientation relative to each other. But from the anatomical point of view, obviously, people generally vary and in this particular case, patient, the orientation between the left and right atrium, the annular inflow, is such that it was so completely different from all the others that it forced the device to sit in a certain position.
And because of that, it resulted in some filling issues, which then led us to try to resolve that by changing the run condition of the device, in fact to extend the filling time on the left side is what we did, by changing the run condition of the device itself, which then added stress to the system.
DR. GRAY: Yes, one quick comment about it is we can check the filling of the device through the transesophageal intraoperative echo and it's very, very accurate and gives us a very good idea. In this particular one, intraoperatively, it looked like it was all right and we thought it was going to be all right, but we had some inflow problems.
DR. FERGUSON: The reason I'm asking this really doesn't relate to that case particularly, but it relates to the fact that the heart is heavy, with a heavy heart, and I am wondering if there is any possibility that there is going to be a malposition that can occur after you close the chest. I don't think this is the case, but I want to bring that out, too.
DR. GRAY: We have never seen that. We have seen malposition as you close the chest and we always close the chest sort of temporarily first and check it with the transesophageal and so far, the transesophageal has been very good. We had one other cases earlier in the series that we had some inflow obstructions of the pulmonary veins and we alleviated that by putting a Gore Tex patch in the diaphragm, which dropped the device down about 2 centimeters and it worked very well after that.
DR. FERGUSON: Thank you. One last point, Bill, and I think this is more of a comment, I guess, than a question. But the device in its present state, and I would certainly recognize that for an artificial heart device, although we have had those around for a long time, this is a totally different, to my way of thinking, much, much better device than has ever been offered before.
I, therefore, think that the sponsor ought to be given every opportunity to expand this. One can always say that the field or the group of patients that are going to be treated with this are, I don't like to use the word, but salvage patients in the sense that they are going to be dead very shortly with nothing done.
But we have an ethical question here. We have 12 patients that have been offered, 14 patients that have been offered and accepted the device. The mean life afterwards, instead of being 30 days as it would have been if they had no device, the mean is 112 days. And so, you know, I think that needs to be out on the table. This is the real issue that we have.
And a comment. On page 9 of the FDA summary, and this will be my last comment, Bill, page 9 of the FDA summary talks about the support time. You don't have to even know the intricacies of this to understand that some of those patients in the first five group, five patient group, were done at Jewish Hospital, because you have a long, long experience with Abiomed yourself before this device came along.
And I just would like to be reassured, I guess, as well as I can that at least we have an opportunity with the patients that will come after approval, if it's approved, will have a survival time which will be better than the last Patients 8 to 14. And that relates to the issue, I think, of where the device is implanted and I would like to hear more information about what your plans are for extension, because this is a very, very difficult surgical procedure.
It's very difficult cardiology management, anesthesia management, etcetera, etcetera. And I can see at least the possibility that down the line with a large number -- not a large, but a larger number of institutions implanting the device, that the survival times may not be as good as we're looking at here even.
DR. GRAY: I hope I can answer this. I think that yes, it is technically a difficult surgery. I think the primary reason it was done at two institutes though, rather than more at the initial time, was we were trying to figure out what was going on with the stroke problem and trying to come up with a solution to the problem with the struts and that is why it was kept in the two institutions primarily.
It is major surgery. There is no question. Rob and I are good surgeons, but we're no better than anybody else and there are thousands of good surgeons around this world. I think that any cardiac surgeon who is capable of doing Ventricular Assist Device work and transplant work is very capable of doing this type of surgery.
The actual postoperative care of the patient is very similar to a Ventricular Assist Device type patient and I think this can be put into other programs that do transplantation and Ventricular Assist Devices. It certainly is not something that should go into a center that does not do transplants and assist devices.
DR. FERGUSON: Thank you very much.
CHAIRMAN MAISEL: Thank you, Tom. At this point we're going to break for lunch. It's 12:35. We will reconvene at 1:35.
(Whereupon, the meeting was recessed at 12:35 p.m. to reconvene at 1:38 p.m. this same day.)
1:38 p.m.
DR. MAISEL: Good afternoon. We're going to begin this afternoon's session. I'm going to ask Geretta to read the voting status statement.
MS. WOOD: Pursuant to the authority granted under the Medical Devices Advisory Committee charter dated October 27, 1990, and as amended August 18, 1999, I appoint the following individuals as voting members of the Circulatory System Devices Panel for this meeting on June 23, 2005.
Eugene Hubert Blackstone, M.D., Thomas B. Ferguson, M.D., Norman S. Kato, M.D., Joanne Lindenfeld, M.D., Thomas A. Vassiliades, Jr., M.D., George W. Vetrovec, M.D., Judah Z. Weinberger, M.D., Ph.D.
For the record, these individuals are special Government employees and are consultants to this panel under the Medical Devices Advisory Committee. They have undergone the customary conflict of interest review and have reviewed the material to be considered at this meeting. This is signed by Daniel G. Schultz, M.D., Director, Center for Devices and Radiological Health, and dated June 17, 2005.
Pursuant to the authority granted under the Medical Devices Advisory Committee Charter of the Center for Devices and Radiological Health dated October 27, 1990, and as amended August 18, 1999, I appoint Drs. Jeffrey S. Borer and Robert M. Nelson as voting members of the Circulatory System Devices Panel for the June 23, 2005 session of the meeting.
For the record, Dr. Borer is consultant to the Cardiovascular and Renal Drugs Advisory Committee of the Center for Drug Evaluation and Research. Dr. Nelson is consultant to the Pediatric Advisory Committee and an advisor to the agency's Associate Commissioner for Science.
They are special Government employees who have undergone the customary conflict of interest review and have reviewed the material to be considered at this meeting. This is signed by Sheila Walcoff, Esq., Associate Commissioner for External Affairs, dated June 13, 2005.
DR. MAISEL: At this point I would like to give each panel member the opportunity to question either the FDA or the sponsor to make some general comments. We have a very large panel today and a number of panel members who need to leave.
I would like to ensure that we all get a chance to say what we want to say and participate in the vote. I'm going to ask you to limit your comments to five minutes and I'm going to be pretty strict about keeping that time if you don't mind.
Tom, why don't you go first.
DR. VASSILLADES: Thank you. I would like to ask the sponsor if they can offer any additional data or information on these 14 patients that speak specifically to the neurologic event-free survival, the bleeding event-free survival, and the quality of life of these 14 patients. That's the only question I have.
DR. DOWLING: Yes. We have some slides. We have a slide problem. I think this is such a big issue is it okay with the Chairman if we wait a few minutes for the slides?
DR. MAISEL: Yes. While we're waiting for that, Mitch, why don't you start and we'll come back to Tom's question when the slides are available.
DR. KRUCOFF: To the sponsors, just a couple of questions. Am I right in understanding the median survival in the slide, I think, Dr. Kung, that you put up from the rematch group was about 20 weeks. Right?
DR. KUNG: Yes.
DR. KRUCOFF: About 140 days?
DR. KUNG: That was the control group.
DR. KRUCOFF: The slide you showed.
DR. KUNG: Right.
DR. KRUCOFF: And the median survival actually in the 14 patients here was about 112?
DR. KUNG: The median survival, yes.
DR. KRUCOFF: Okay. So -- well, let me say it's just going to be safe to assume that all of the point estimates that we're seeing from 14 patients would have confidence intervals that would be very wide. Is that a fair statement?
DR. KUNG: Yes. For the number of patients we have, the answer is yes. However, if I may venture just to remind the panel that when we started a trial before the enrollment got to a point where we decided and with the concurrence of the FDA that the HDE was the right approach, we at one point did have quality of life measures designed into the trial.
But, again, because of the conditions of the patients, much of that data was not fully collected and I presume -- I think from the HD point of view that's not something that is required, if I understand that correctly, from the FDA.
DR. KRUCOFF: I think the tough thing -- I'll just speak personally -- the tough thing for me is to talk about probable benefit balanced against safety with this set of information.
I'm not even sure I would call it data but with the experience today, I feel like it's on the very narrow edge between what would be approval leading to clinical use while we are still, and you are still, obviously learning a lot about patient selection, anticoagulation, and other things, versus what we really ought to suggest needs to be continuing research, not clinical use.
I'm just trying to get a sense for myself of where, if anywhere, could we lock onto data that would help understand the safety and balance that against probable benefits. Probably related to Tom's question, but let me just ask is it safe to say also there's no information about the emotional projectory or quality of life over time in these folks relative to their physiologic recovery?
DR. KUNG: I think the so-called emotional one I'm not the person to qualify to tough upon that other than for those patients that I personally was in contact with, also with the family and so forth. I mean, what I have observed and from that point of view, not a physician's point of view, but a layman's point of view is that every interaction, perhaps for one or two cases, were that between the family and the patient was a worthwhile experience.
DR. KRUCOFF: Right. Although, as we heard earlier, in at least one individual's case with obviously a loving and supportive family, what was elected to go through once, and what was appreciated and even physiologically benefitted him once, was something that he would chose to not do a second time for whatever reason. Is it fair to say that we don't have a lot of information characterized in the longer-term emotional states of these folks once the device is implanted?
DR. KUNG: Well, we have another patient that went 290 days, or 293 days, and that particular patient, I think, enjoyed quite a bit that extended period of time.
DR. KRUCOFF: So if his device was failing, do you think he probably would have been reoperated?
DR. KUNG: He was a much younger patient so, in that particular case, probably -- well, again, that's speculation but I would say that would have been potentially a case that replacement would make sense and might have agreed to it.
DR. KRUCOFF: Shift of gears. Let me just ask in the device itself, in some other devices like AICDs there's an internally monitored history so that if the device enters a failure mode or whatever, you can actually look back at that history. It's almost like having a black box on an airplane.
Does either the external unit or the combination of internal and external store information so, for instance, the patient whose device experienced bearing failures, is there a storage of the relative pressures, the speed, the rotor spinning, or other elements that could be useful technically to see trouble coming?
DR. KUNG: The answer is yes. Actually, I can pull one up to show you.
DR. KRUCOFF: It's there. I guess that's my real question.
DR. KUNG: It is there. We have all the pressure information. We have all the LODO information, RPM information from the device which are broadcasted essentially to the external console which picks it up. We actually can hook up remotely and get the information to a central station to allow either the physician or, in some cases, the engineers to monitor and make sure that the device actually is working fine. It is actually in using that communication methodology we were able to monitor one of the patients that ended up with a membrane where many, many days before --
DR. KRUCOFF: It actually was fractured.
DR. KUNG: To the point where the flow was low enough.
DR. KRUCOFF: Yeah. Okay.
DR. LINDENFELD: I wanted just a point of clarification. You said the one patient lived 290 days but is that --
DR. MAISEL: Joanne, sorry to interrupt. We are actually going to try to stay on point here.
DR. KRUCOFF: I only have two more questions.
DR. LINDENFELD: It's just this one patient lived 290 days but wasn't he only in a hotel from day 70 to day 90 and was readmitted and remained for the next 200 days in the hospital?
DR. KUNG: Well, he came back to the hospital but his condition after he got back to the hospital, in fact, the latter part of, I think, close to four months we were trying to get him home. We were trying to get him home because of the home electrical problem. That wasn't something that was easily solvable.
DR. KRUCOFF: I just have two more quick questions. We heard, and I apologize because I don't remember who showed the ease with which one of these devices might replace another by the way you have created the snaps.
DR. KUNG: Yes.
DR. KRUCOFF: Can I ask once you put one of these things in a human being, say a human being who isn't a transplant candidate because they are just too sick. They have multi-system failure, etc., and they turn around and that reverses. Their liver failure reverses, their renal failure reverses so they become a transplant candidate.
I'm a cardiologist, not a surgeon so I'm going to ask the experts. Once you have one of these in a human being if they were to be deemed to be a transplant candidate and a heart was available, could you put a heart in?
DR. GRAY: Definitely. Absolutely.
DR. KRUCOFF: Okay. Thank you.
DR. MAISEL: Tom, do you want to ask your question again now that the slides are up?
DR. VASSILLADES: My question related to asking the sponsor if they could provide additional information regarding neurologic event-free survival and/or bleeding event-free survival on these patients.
DR. DOWLING: Yes. Thank you very much for that question. I think that is really one of the crux of the matter here. We did try to put out the information in maybe a more cogent way to make it a little bit clearer for everybody.
We tried to break it up into three groups of patients based on the changes that were made as occurs in any clinical trial. As you see here, we came up with three different groups. The first group are the patients one through five. The inflow cuff configuration is shown in this column right here. So in the first five patients they had the original atrial strut and the stroke incidence was three out of five, 60 percent. Again, small numbers.
The second group was patients eight through 11. Patients six and seven were the early operative mortalities. Obviously, we didn't think it was fair to include them in any of the outcomes in this area.
These patients were the ones that after going to the animal lab and doing some implants with the Texas heart people that were done without the presence of an atrial strut. You see the stroke incidence here, two out of four. I am going to go over each of the patient groups and try to explain even further to address your questions as best we can.
The third patient group, the recent patient group, patients 12 through 14, had a redesigned atrial strut and cuff. I have explained the redesigns previously. I'm not going to do that again unless he would specifically ask that question. The stroke incidence in these was one out of three. Again, I'm going to have a slide and give very briefly all the different groups.
This is group one where three out of the five patients had a CVA. Just to refresh your memory, it was the group with the original atrial cuff and the original atrial struts, flat cuff, high struts contacting with atrial tissue.
All three of the patients that had a stroke were found to have significant thrombus on the atrial struts. I'm not talking about tiny little things. I'm talking about major significant thrombus on the atrial struts that were coming in contact with the atrial tissue, no thrombus, and the struts that weren't contacting the atrial tissue.
In the second group two out of the four patients, again to refresh your memory and mine as well, had no atrial struts. Two out of the four patients had a stroke. One patient a stroke was unknown etiology. He had a diagnosis of heparin-inducted thrombocytopenia with thrombosis. He had multiple areas of infrac that is typical for HITT on his toes, etc.
When we asked the neurologist and so forth if they thought this was thromboembolic, they said it wasn't very likely to be able to generate that many tiny thromboemboli so we don't know. We can't say it wasn't. A big device was in place but the tentative diagnosis was HITT with diffuse intervascular coagulation.
The only other patient in this group, there were two, and I left out the bullet point here. The other patient in this group that had a stroke had a prolonged period of time where he was not able to tolerate anticoagulation.
What about the most recent group? This is probably the one that is of most interest, as Dr. Ferguson was alluding to earlier, group three. It included three patients and one of the three had a stroke. This is a group, again to refresh everyone's memory, that had a new atrial cuffs, codafil design, struts, low profile.
Again, patients 12 through 14. People are trying to correlate that with their packets. All patients eventually expired and none of the patients had thrombus on the atrial struts. They also had good endothelialization up to the struts. We were happy to see that.
Patient 14 did have a stroke. He was the most recent patient. He had prolonged periods of time, we actually looked it up, 164 days where he was off all anticoagulation. The major reason was diverticulosis.
He did develop on a post-op day 132 a clinical moderate CVA with a potential for recovery and he was recovering, getting back to some of the questions earlier about time from new event to time of withdrawal of support. About a month after his stroke he developed progressive deterioration, multi-system organ failure, and then was removed from support.
Just to go back real briefly to summary slide, again, patients one through five, first group, three out of five original atrial struts. All had thrombus on the atrial struts, problems with the atrial struts, the inflow problems we talked about. Maybe a patient with HITT, patient without anticoagulation with a stroke. Twelve through 14 with the redesigned atrial cuff. The pumps all were entirely cleaned. The struts all were entirely cleaned. Stroke incidence as you see there.
This is a summary slide again just to go through all the patients that had stroke again because, you know, as you all have been asking, this is very important. These are all the patients that had a stroke by number. First patient had a stroke and it was the cause of his death. He had no anticoagulation prior to stroke.
The third patient had a CVA while on anticoagulation. We think it was strut related. The fifth patient also had a CVA. He was on anticoagulate for over four months prior to the stroke. Was also one of the three in the first group that had a stroke with thrombus on the atrial struts.
The ninth patient, we mentioned, had DIC. He was slow to wake up from surgery. As I mentioned earlier, he was transferred to the floor. There was signs that he was recovering. The family was kind of hanging on to those signs. The tenth patient had a CVA. He was on low anticoagulation for one month prior to his stroke.
The fourteenth patient I described in detail was off anticoagulation for 164 days before stroke primarily due to diverticulosis. Had a moderate stroke, seemed to be recovering, and then developed multi-system organ failure.
DR. MAISEL: Thank you very much for your comments.
Tom, did you have any other questions? Okay. Sharon?
DR. KRUCOFF: I'm sorry. I have one last very quick. Can I just ask for a yes or no answer? Is it fair to say that as of today if the device was used simultaneously in patients at the Texas Heart and Louisville or other centers, the likelihood is that the anticoagulation regimens at each hospital might be a little bit different one from another?
DR. DOWLING: I hope they would be at most a little bit different. I think we would spend a significant amount of time educating other centers what we thought was appropriate. I think we would tell them this is one of the major lessons we learned. We'll pick centers we think that would be able to follow that.
DR. MAISEL: Thank you. Sharon.
DR. NORMAND: Thank you. I only have one question and a little bit of a concern. It really relates to the place where there are numbers and that is your scoring system for predicting the probability of 30-day mortality or 30-day survival.
I guess I'm having a problem with the fact that I heard it was proprietary. I find that bothersome. That's the word heard earlier and I don't see that in the input information so maybe someone can tell me is it or is it not?
DR. DOWLING: It's been published in the Journal of Thoracic and Cardiovascular Surgery. I can provide you with the reference.
DR. NORMAND: Okay. So we know the weights that are going to be used on those things. I don't care about the components but the weights that are used on it.
DR. DOWLING: Yes. Correct. Exactly. The whole score is published.
DR. NORMAND: Okay. Good. So that's reassuring. But the other thing that I worry about, and I think it was mentioned in the FDA summary, is that I think I'm confident that screen system is built on a different population for the one that you're targeting it to. I would worry about the ability of your covariates to discriminate well among a more homogeneous population to which you are going to apply this to.
I guess I would urge more study of this particular system to predict 30 days survival and mortality, however you're looking at it, because you are applying it to a very specific subpopulation. From my understanding of the material that I was given the actual system was built on a data set that is somewhat different than the population that you are considering.
For that very reason given that your population is very homogeneous, and admittedly you're saying very, very sick, I worry about the ability to discriminate well survival among the patients that you are going to use it in. Hence, I worry about the point estimates and things such as that. It is sort of a scientific remark that you really do need to validate it in the population that you are using because I don't believe it in terms of the numbers I'm getting. Thank you very much for a good presentation.
DR. MAISEL: Chris.
DR. WHITE: I would like to ask you about your anticoagulation. When we have been concerned about the bi-directional, the double-edged sword of bleeding and stroke. You've said in very clear details that even an interventional cardiologist can understand. I understand about the struts, I understand about contact with atrial tissue, and I understand about the evolution of your anticoagulation regimen over four years.
What I guess I don't understand is you sound to me like you have confidence that you sort of solved these problems but the data doesn't track that way. I mean, wouldn't you like to see three or four or five patients go without a stroke to make you think that you have solved the problem? I understand your rationalization behind the changes and I think they have been logical but I just don't know that they've been effective.
Then you mentioned the TEG today and you've been using the TEG to perhaps better optimize your interplatelet therapy, but you are still having those strokes. Do you think that's going to -- I guess what is your optimism for being able to solve this problem? It reminds me of the old days of coronary stents when we had almost 11 and 15 percent risk of transfusion people with dipyridamole, heparin, aspirin, every antiplatelet we could put in these guys, and they all bled.
Now we've got down to just using clopidagrel and we have much fewer bleeds. It seems to me like you are still in the process of trying to figure out the best way to stop the bleeding and yet still try to prevent the strokes.
DR. DOWLING: To answer the first question, would it be nice to have three or four or five patients in a row, it's obviously yes. I think when we look at the -- I hope I'm not coming over as overly optimistic. I think we all try to be realists, especially in clinical medicine. I do think if you look at the patients that have had strokes, especially in the recent series, it's been those patients that haven't received any type of anticoagulation that have bleeding problems.
The one thing that I would want to have is patients with better nutritional status and patients that didn't have bleeding complications that come up in the post-operative period and be off anticoagulation for 164 days. I think it gets at what Dr. Ferguson said, the more we put in somebody, the more likely they are to have a stroke if we stop
anticoagulation. I don't know if that got to your question or not.
DR. WHITE: I think you are well meaning but I don't think you have data to say the changes you've made have impacted the outcome. The other part of it is why is it that we are not considering this device as a bridge to transplant? Why is it that we're only talking about end-stage patients?
DR. MAISEL: I will just comment that if you do not want to answer that question, you don't have to because --
DR. WHITE: Is that out of bounds?
DR. MAISEL: I think we are considering the device as destination therapy here today. The sponsor is certainly welcome to respond but you are not obligated to.
DR. WHITE: I just heard a couple of times where we've learned that this device doesn't preclude a transplant so I'm just wondering why we are focused on such a tail end of the patient.
DR. KUNG: Actually, in the original design of the trial where we first started with the 15 patients we required that the patients stay on the device for a minimum of 60 days beyond which if the patient were qualified at that point in time for transplant that they could. That was part of the protocol.
It just so happened in these 14 we never got to any patient that was at any point beyond the 60 days that were qualifiable because some of the patients, the younger ones had high PVR. The high PVR actually did not change over time. It didn't go up and it didn't come down. It was a chronic situation so they weren't going to be qualifiable after 60 days so we didn't get one. The intent originally was exactly as you have stated.
DR. MAISEL: John, do you have any comments?
DR. SOMBERG: I'll pass at this time.
DR. MAISEL: Okay. Clyde. Joanne, please. Clyde, go ahead. It's your turn. You're up.
DR. YANCY: I just have a couple of short considerations. Even though the last product iteration may have reduced somewhat the anxiety about stroke, but it's now improving and I think Chris makes a good point, the median survival of those last three is still very poor, less than your best case scenario. Again, it raises the question of why at this point in time at the end of 14 are you comfortable going forward with a broader use since I don't yet see evidence that the most recent product iteration has fundamentally improved that one method of survival.
DR. DOWLING: Well, one of the patients, Dr. Yancy, the 13th patient, had the device stoppage. I would like to emphasize that discharge planning was being made for that patient. The 12th patient was the one that Dr. Delgado mentioned where they probably had hepatic cirrhosis that was missed on biopsy and led to his poor outcome.
The final patient was one of the older patients and, in retrospect, was probably just too ill. He died eventually from multi-system organ failure. It really, I think, reflects inclusion criteria and the fact that we wanted to be very selective about who we put it in.
DR. YANCY: Let me just take you one step further and that will be the end of my questions. In view of what you just said, the necessity for even more stringent inclusion criteria, and even within the group that you recruited significant heterogeneity appeared to be present. Again, the number is extremely small.
Why then would part of the application be for not only the current patient population but an expanded patient population that admittedly includes non-LVAD patients and patients in whom it's not even an end of one experience? I'm trying to understand the rationale for extending it to an even more diverse patient population.
DR. DOWLING: That patient population was included in the initial IDE. There were a lot of logistic problems, as you can imagine, being a practicing clinician with trying to enroll someone in this type of study who just came in with an acute MI or other problems.
DR. YANCY: I could also clarify that. That extended patient population is not on the table today. I mean, we are here to debate the HUD and HDE as described so the extended patient population --
DR. DOWLING: Well, the only point of clarification is that it was part of the sponsor's presentation. It's in our documents and appears to be part of the application for HDE approval. If I'm out of order --
DR. YANCY: Would say we don't have the authority to approve indications outside the HUD.
DR. MAISEL: Would you like to comment?
DR. ZUCKERMAN: Yeah. I think we have done a good job of confusing you here today. My apologies. Again, the HUD is for a limited medically plausible subset that is biventricular failure, destination therapy and nontransplant eligible. That's the universe. Those things that you are all referring to are outside the box. They could be considered under separate IDE clinical trials. Perhaps when we get to the discussion section we can discuss that.
DR. YANCY: I'll defer to the discussion then. Thank you, Dr. Dowling.
DR. DOWLING: I agree with you, though, we should get more experience in the group with more experience before we go further to other patient populations.
DR. MAISEL: Rick.
DR. PAGE: I'll keep my comments brief. First of all, thank you for your presentations. With regard to the efficacy of the device going through the patient reports, there are several comments of a fairly high maintenance required for these patients should they make it out of the hospital.
Can you comment on what you would envision if only two made it home, if you will? What would you anticipate in terms of nursing care or sophistication of the support group at home for patients if you have a number of these patients actually discharged to home?
DR. DELGADO: I would just say that I think it's probably similar to an event population. That population most of them have driveline infection, wound dressing changes and such and maintenance of a powerbase unit at the bedside at their home.
Then keeping batteries charged and training a person that is going to be with them. I think it would be very similar with this. The difference would be instead of a driveline there would be the TET coil that would have to be kept in place and duaderm type dressing would have to be maintained. Beyond that it would be very similar to LVAD population. I currently have an outpatient in an LVAD clinic in which we see approximately 10 to 20 LVAD patients in the outpatient clinic who come in weekly for outpatient visits. It's a matter of training the family members and caregivers.
DR. PAGE: When you reach steady state would you envision that it would be better than the LVAD because the LVAD population did require a fairly high level of sophistication of help at home. We would hope for something better than that.
DR. DELGADO: Right. I do think it will be better actually because one thing I noted in having managed hundreds of LVAD patients and having managed five AbioCor patients, the actual medical management issues are much easier in the in-patient arena than in LVAD patients. With LVAD patients you have to worry about right-heart failure, treat them with pulmonary invasive dialators, right-heart inotropic agents. No such thing with this device.
Also, you don't need an electrophysiologist -- sorry, Dr. Page -- because there's no rhythm abnormalities. In those two ways it actually is easier than LVAD. I personally believe that is the case. Definitely for in-patient, probably for out-patient.
DR. PAGE: Okay. I have no further questions. Thank you.
DR. MAISEL: Thank you. Gene.
DR. BLACKSTONE: I have several comments and a couple of questions. First from a statistical point of view, on page 13 of 20 in the summary of safety and probable benefit, all of the events are expressed as if they occurred at a constant hazard rate. Having analyzed repeated events in LVADs, it is rare that these are at constant hazard rates. I don't know how to interpret the fact that you have couched all these events as constant hazards.
This is somewhat akin to what we find under the clinical summary on page 31 of 81 in which hospital stay is presented as means with standard deviations much larger than the means. Those are also what I would call bogus statistics on those.
On page 17 of 20 you have a time series of a bunch of measurements that are measured across patients that presented as each observation is independent. Yet, various patients have different lengths of time and so some sort of longitudinal analyses of these data would help us know what is actually going on.
I make those three statistical comments because I find it difficult to interpret the data when they are presented in ways that are unhelpful and I think incorrect.
Now to Sharon's question about the model itself which you give on page 48 of 81 in the clinical summary on your model for risk. This appears to be based on a number of different variables that have been given, just Delphi type of weights, not statistical weights. It's based on four variables, one of them being ranges of age.
Then three composite clinical, one based on ten of 15 variables for variable A, six of seven for variable C, eight of 16 variables, I guess, for C, six of seven for B. Then with some kind of calibration to 27 events of 42 patients that you gathered from four different institutions. I would think that, first of all, the weights themselves are not generated, it appears, from actual analysis of data.
Secondly, I would imagine that the confidence limits for these are extraordinarily wide so that when you say that these patients have 70 percent chance of dying within 30 days, I would imagine the confidence limits for those estimates at 70 percent would be extremely wide. I'm not at all convinced the fact that you say you have published it in a journal of which I'm an editor doesn't make me any happier.
One other comment. That is, if you look at the instructions to the physicians and then especially to the instructions for the patients, the writing is absolutely horrible, embarrassingly so. Incomplete sentences, abbreviations all over the place given without antecedent definition of those. Sentence structures that stop in the middle of sentences. I think you need a professional writer and someone who can put this for the patient down to the 8th grade level in a way that families can understand.
Finally, a question. That is, in the two major institutions that were putting in these devices, given that this was a four-year period of time, concurrently with these implants how many patients in your institution actually receive destination LVADs concurrent with this?
PARTICIPANT: Let me comment on that because destination LVAD wasn't available during most of that four-year period of time, only --
DR. BLACKSTONE: Does that mean then that it is likely that these patients would be what we would call today destination patients? Does that help explain the problem that we have had this morning that many of these don't appear to be biventricular patients but would be patients that we might consider today for destination therapy with LVADs?
PARTICIPANT: That's a hard question to answer but I don't think that any of these patients in my mind, any of the five patients that I was involved with, were candidates for LVADs period in any way, shape, or form. They were in general too ill. That is the best way for me to put it.
As far as assessing right-heart function, very difficult to do. You can tune up any patient to make them look good on the right side. Some patients had other indications like pulmonary hypertension due to a high PVR which wasn't right-heart failure.
It was just pulmonary hypertension. If the question is could we now treat this same patient population with destination LVADs, I think the answer is no. This patient population would have an inexorably high mortality risk, I believe, with standard LVADs.
DR. BLACKSTONE: Thank you.
DR. MAISEL: George.
DR. VETROVEC: One question that I don't think has been addressed yet is there is this relatively high infection risk. Obviously this is a sick population of patients. But then there is kind of an ill-explained bleeding problem that may be outside of all the drugs.
I guess the question I have is has anybody really looked at the function of the white cells? Is there something about turbulence with this device that yields the white cells to not function normally and is that contributing to the infection risk?
DR. DOWLING: Just by chance we studied that just because I happened to have a student who had a masters in the appropriate study. We looked at this first in cows. He found some antibodies in the cows. At the time there was a lot of controversy about inflammatory response and white cell disfunction after the heart made one device.
In the animal model we didn't see any evidence of immune system dysfunction in the animal model. Then we looked at it in the few humans that we had, I think the first four or five patients. At the same time we looked at our LVADs that were undergoing concurrent operative therapy and we found that again in -- we showed it basically with the Columbia group that the LVAD does very much does affect the white cells in the immune system regulation but the AbioCor did not.
DR. VETROVEC: The second question I have, my last question, has to do with the fact that I think there were six centers and only four did implants and really it was mostly two. I guess one of my questions is was the limit in some of the other institutions in any way restricted by their IRBs as they started to see this data come out?
DR. KUNG: No. In fact, all the IRBs approved the protocol. It was just that they didn't find any issues.
DR. MAISEL: Dr. Kato.
DR. ZUCKERMAN: Dr. Maisel, before we go to the next set of questions, could the agency just comment briefly on the inclusion/exclusion criteria and what we thought of the makeup of the patients who entered the trial?
DR. MAISEL: Of course.
DR. PINA: Illeana Pina, consultant for the FDA. I have also reviewed this application. In answer to a question that was asked here about destination therapy I couldn't hear. I would assume right now that it would be strictly left ventricular dysfunction. One question that I think we have brought up is whether these would be transplant candidates.
In fact, in other institutions that maybe the age range is a bit broader. Perhaps Dr. Lindenfeld may want to comment on that when it's her turn. I think that is another interesting question that needs to be asked, not just destination but transplant.
DR. MAISEL: Thank you. Dr. Kato.
DR. KATO: Just a follow-up to Dr. Blackstone. One comment by the sponsor was the patients were just too ill. One of the things that we've been striving here for is to have some evidence. Some qualitative comments like the patients are just too sick, do you have any data to support that qualified statement?
DR. KUNG: I did show, I think, this morning some slides regarding the sodium levels and the systemic pressure. We are looking at it from the point of view of Lynn Stevenson claiming that those are very important parameters that determine the severity of illness of heart-failure patients. I am just showing the numbers. That is sort of part evidence that these patients were sicker than the LVAD patients in the trial.
DR. KATO: We as the clinicians taking care of the patients, we obviously felt they were sick, sick enough to go under the study. The predictors of mortality and heart failure when you get to this level become murky and the ability to study heart failure patients with this degree of illness is very difficult and gets more difficult as they get sicker.
To my knowledge this is the sickest heart-failure population I've ever seen studied in any way. A lot of it comes down to the judgment call of clinicians who have a lot of experience taking care of sick heart-failure patients and that's an unfortunate fact.
One other comment is that I'm still drawn back to this patient No. 9. Being comatose for 53 days is a problem. And this being a study, these patients were under study and then for a patient to have what looks like minimal return of neurological function being allowed to lay in a ICU bed for most of those days before being transferred to the floor it seems to me almost as if -- and I'm not making any allegations but it would appear as if the institution was just trying to hit the 60-day minimum.
Can you comment a little bit more about patient No. 9 and perhaps some of the safeguards that you would envision for the future if you are going to proceed with an additional 20 patients?
DR. DOWLING: Well, certainly on behalf of the clinicians I don't think anyone would ever have considered if the clinicians in the family agreed that we would just continue support to reach a date milestone.
One of the main reasons that the advocate was instituted in the system, which I think was an unprecedented move, was for situations like this so the advocates can work with the physicians but mostly with the families to determine when to stop.
I can tell you that patient did have some signs of neurological recovery and it made it very difficult for the family to withdraw support. As one of the main physicians taking care of that patient, my thought was that we probably should have withdrawn support before the family was ready to but you've been in that situation, too.
The family is just not ready. They are seeing him move. They see him detract, to interact some, to squeeze hands. They are not able to distinguish reflexes. You know, "Dad is in there." The fact that support was withdrawn before the 60-day mark suggest we weren't trying to reach that goal. I mean, at that point we were well into the study.
I don't know but I would just reiterate from a clinician's point of view I have never, nor any of my colleagues, would keep a patient alive to reach an artificial endpoint. I just think that's entirely -- would be entirely inappropriate for us to even consider that.
DR. KATO: Is it anticipated that you are going to have these patient advocates for the next series and is this part of what you would consider to be part of the program for other institutions utilizing this device if it were approved?
DR. KUNG: We would certainly condone that approach. I believe it worked extremely well from the patient's and family's point of view to give them that extra advice mostly from the medical point of view and also from the personal point of view.
DR. DOWLING: It worked out well for the physician as well. It's a source of comfort for us and support for us.
DR. KATO: Thank you.
DR. MAISEL: Thank you, Norm. Judah.
DR. WEINBERGER: I think we've asked almost all the questions and I just have one or two very brief ones. The bleeding that was observed, was that observed primarily around the operative time or was there late bleeding as well? We've heard a lot about how you have to be careful with reperfusing the patient and not over-circulating them.
DR. GRAY: We had problems with early and late bleeding. The late bleeding, in my opinion, was sometimes related to over-anticoagulation. Some of it was related to -- the diverticulosis, the patient just had it.
There was an early bleed, in my personal opinion, that was related to the fact we were perfusing him too much so we had both and then we had significant amounts of interoperative -- not interoperative but postoperative tamponade or bleeding secondary to early or beginning of heparin.
Now, that decreased in the later group. We had more problems as we were getting started on that with the earlier takebacks for tamponade or part of not initially true tamponade but myocardial compression.
DR. WEINBERGER: Okay. This is one for the surgeons. If you have a competent cardiac surgeon, the technique of implanting this device aside from the patient's selection issues and the postoperative issues, how difficult is that to transfer that information from one competent VAD surgeon to another?
DR. GRAY: I do not think that is an issue. I think that any competent VAD surgeon would be able to do this with ease.
DR. MAISEL: Thank you, Judah.
DR. BORER: My questions have been answered. Thanks.
DR. MAISEL: No, thank you.
Dr. Nelson. No further questions. Linda, did you have -- are you all set? Joanne, did you want to ask a couple of other questions?
DR. LINDENFELD: Just two very brief comments. One is that although I think you've shown some nice data that there is less thrombus in the struts and you showed us the data for the strokes, three out of five in the group one to five, and only one out of three in the last group, the duration of follow-up was half in that last group so it's 230 days versus 130 days.
It's a lost less time to have a stroke. I'm not comforted by that data. I just wanted to say thank you to the families who came. I think your loved ones' contributions will be just enormously valuable in the development of these devices.
DR. MAISEL: Tom, did you still have a question?
DR. FERGUSON: I just had one quick question about patient No. 14, and t his applies to the rest of the group, I guess. That patient went through the surgery and did quite well for a period of time and then died of multiple organ failure. Yet, we were told that this machine will keep you alive forever if you want to stay alive. My question is, laymen, what is the genesis of late organ failure in a patient that's on the VAD?
DR. GRAY: This particular patient is a patient with diverticulosis and he started having GI bleeding and it was fairly massive GI bleeding.
DR. FERGUSON: I see. Okay.
DR. GRAY: Then he had interabdominal problems that led to the renal failure.
DR. FERGUSON: I gotcha. But in the ordinary situation without a complication, a major complication, reversal of organ function, even if it's very bad initially, is what you would expect. Right?
DR. GRAY: Absolutely. We have been very impressed with in particular some of the liver failure and renal failure. It's very impressive the reversal of it. I really think that has a lot to do with some of the right ventricular support that is given.
DR. FERGUSON: Thank you.
DR. MAISEL: John.
DR. SOMBERG: If this was to go forward, are you going to stick with the 75 cutoff or is that going -- since two of the patients of the 14 were actually over 75 and one of the reasons to consider this is that they are not transplant appropriate due to age and that biologic age is maybe more important than constitutional age. Is there thought to not necessarily adhering to that or is 75 going to be enforced?
DR. KUNG: The reason that 75 years old was put in there, actually this is part of the HUD application. We looked at the mortality as a function of age on major procedures and it turned out the influction point happens to be close to around 75 years old. Then that was what was proposed. Then it was accepted by the FDA. That really was the primary reason for that.
DR. MAISEL: Okay. Thank you very much. At this point we'll move on to the FDA questions. I would like to have Geretta read the first question.
MS. WOOD: If we could get our AV people to help with the computer, please.
DR. PINA: Mr. Chairman, may I show one piece of data that I think will help clarify the level of sickness of these patients?
DR. MAISEL: Yes. Please do.
DR. PINA: Thank you. Obviously the level of sickness in the heart failure population is a very important issue that we are discussing here today. Dr. Delgado is right, it's made up of multiple items including things like sodium, hemodynamics, response to medical therapy.
These are the means taken from the hemodynamics that were provided by the sponsor to the agency in the sheets that you now have as patient summaries. The mean cardiac index is 2.1. The mean PA pressure is 34. Of course, these patients were multiple therapies.
We do not know the oral therapies but we do know the inotropes F17. The mean serum creatine was 1.7. The highest creatine seen is 3. Creatine is very much a predictor of bad outcomes in heart failure.
The mean systemic vasculary systems was 1,200 and the transpulmonary gradient, which we use as a difference between the mean PA and the wedge, was approximately 15. Generally you would like to get it below 12 for transplant and eight patients were below the age of 70 as one of the contraindication to transplant. I hope that helps.
DR. MAISEL: Thank you very much. Would the sponsor like to comment or respond to that? I just wanted to give you a chance before we move on. Okay. Thank you.
Geretta, why don't you read the first question, please.
MS. WOOD: I'll go ahead and begin reading the first question there. Evaluation of patient selection and inclusion/exclusion criteria. The Feasibility Study was designed to include up to six sites. Most of the patients (12/14) were implanted at two centers (University of Louisville Jewish Hospital with seven patients and Texas Heart Institute with five patients).
Please discuss whether there is reasonable assurance that the results from Jewish Hospital and Texas Heart Institute can be generalized to United States transplant centers that would implant this device.
DR. MAISEL: We certainly touched on some of these issues. It seems like the main generalizability focuses on two areas. One is the
anticoagulation regimen and one would be the training of the surgeon and patient selection issue.
For me, I'm not sure the anticoagulation can be expanded to other centers if there's not agreement among the centers that are currently involved in the study. The training we'll deal with on another question but I think in general the panel has been able to devise training plans that can overcome the generalizability issue. Could I hear from other panel members regarding the generalizability? Any other comments?
DR. FERGUSON: I would take Dr. Gray's word for the ability for this to be done other places.
DR. MAISEL: How do other panel members feel? Mitch.
DR. KRUCOFF: I think one point that came up, in fact, I think it was the sponsor's note that it would be important, would be this is generalizable potentially to hospitals that have teams that can coordinate the necessary many levels of the care of these patients in transplant centers.
DR. MAISEL: How do people feel about the anticoagulation issue?
DR. NORMAND: I would agree with what you have summarized. I think that the training is generalizable. I just don't feel comfortable that I could understand what the current recommendations are for anticoagulation and following it so I think that is not generalizable.
DR. MAISEL: Chris.
DR. WHITE: I would also agree about the anticoagulation issue. I actually have some general concern about rolling it out to 10 sites when they weren't able to roll it out to their six. I just think they haven't walked yet so it's maybe not time to run.
DR. MAISEL: Rick.
DR. PAGE: I'm impressed by the fact that the best survival was seen among the first patients who underwent this procedure suggesting there is not a steep learning curve. I would hope other centers would be able to entertain this procedure with as good results in terms of the anticoagulation.
I have less trouble perhaps because, as I see it, this is such a sick population that a number of the problems, at least more recently, have related to the fact that they have bleeding related to other underlying disease. I can't expect the device to go without thrombus if the patient is not anticoagulated.
DR. MAISEL: Clyde.
DR. YANCY: I would really have to support Mitch's statement. Any center that does transplantation doesn't necessarily have the wherewithal and the infrastructure to handle mechanical devices. I really think a tighter group is the better approach who have demonstrated that they have the infrastructure and personnel to really deal with the very ill and very selective patient population.
DR. MAISEL: I don't feel like I have a sense of exactly where the panel sits on the generalizability issue. If we are just talking about the HDE and this application, do you feel it can go out to the other centers as suggested by the sponsor? Jeff.
DR. BORER: I think that the techniques can be transported. I don't have great concern about that. I think that the anticoagulation issue remains open but, you know, demanding a well-defined anticoagulation regimen based on the data that have been put together thus far I think is probably unrealistic.
I don't know that there's a basis for defining a best anticoagulation regimen. It sounded to me as I listened to the presentations as if the people who were doing these implants and doing the studies were in pretty close communication with one another and were benefitting from the experience of one another.
I think that should continue. Now, we could say, and the FDA could certainly recommend that a baseline protocol for anticoagulation should be devised with the capacity for its immediate alteration in specific situations of hematologists and other clinicians that the particular center believe that's appropriate for an individual patient.
That may sound better on paper but I'm not sure as I listen to the presentations if that is very much different from what the investigators have been doing. Yes, there's a problem with anticoagulation but I think in general this procedure with all that it entails could be transported.
DR. MAISEL: Any other comments on that part?
DR. VETROVEC: I think if I can say what sounds like the panel said, it's not that it can't be transported out. It's the selection of the sites that it needs to be transported out to and the time course over how many sites you set it up.
DR. FERGUSON: I was going to comment too, if I may. I don't know of any -- maybe I'm wrong but I don't know of any transplant center in the country that doesn't do sizable number of patients off LVAD so they have the LVAD experience in the transplant center. That is sort of what I was referring to, Clyde. Maybe it should be more defined than that, though.
DR. MAISEL: Why don't we do question 2.
MS. WOOD: Please discuss whether the Feasibility Study inclusion criteria appropriately selected patients for the study.
DR. MAISEL: So, again, let's focus on the inclusion criteria and not the other indications that were listed.
Joanne, you raised some questions about the biventricular failure and the definition of right-heart failure. Would you like to comment on the inclusion?
DR. LINDENFELD: I think there's two issues for inclusion. One that Dr. Pina brought up is that some of these patients might be transplant candidates at some centers, although I think that is sort of a moot point because they weren't by age at the centers where they were but I still am concerned. I know these are very difficult and I respect these centers' ability to judge who is not a candidate but when one sees several patients with pulmonary wedge pressures in the 20s and CDPs less than 5, it's hard for me to imagine that some of them might not be a LVAD candidates so I'm still concerned about that issue.
DR. MAISEL: Mitch.
DR. YANCY: There's very brief reference to psychosocial evaluation that leaves me concerned, particularly with a device that is a end-of-life application that may bring with it a relatively high risk of neurologic events. I think the psychosocial evaluation for selecting patients or families who are ready to deal with this knowledgeably needs further definition.
DR. MAISEL: Probably should be very much like a transplant evaluation.
DR. YANCY: Certainly more than are you really going to quit smoking.
DR. MAISEL: Jeff.
DR. BORER: I think we should make a distinction between the inclusion criteria, which is what is stated here in the question, and the means of measuring those criteria. I look at the list and I think the list is pretty reasonable. I look at the exclusion criteria and I think that list is pretty reasonable.
I think the questions that have been raised have more to do with how those criteria were demonstrated to have been met. I agree with that but I think that is a separate issue. We probably will talk about that later. I believe the inclusion criteria reasonable.
MR. MORTON: Well, it is within our purview to say "biventricular failure as evidenced by" so if there is some right-heart failure bar you want to set, we could discuss that.
DR. BLACKSTONE: Okay. I was going to bring that up later if somebody else didn't. Yes, I think that the FDA would be well advised to, No. 1, attempt to obtain data that we haven't seen that may be available. These patients had charts. They had a great deal of information available.
We haven't seen all that, and maybe the FDA hasn't seen all that yet. I think those data from the patient's charts ought to be made available to the FDA to determine whether it is, in fact, demonstratable that these people had biventricular failure which seems to me to be the greatest point at issue.
I'll tell you as someone whose primary research focus these days is valvular heart disease, I spend a lot of time studying chamber performance and right ventricular function. I am very sympathetic to the investigator's statement that the CBP alone or the relation between CBP and wedge is not really the be all and end all for determining what the right ventricle is doing particularly in a setting of multi-modal therapy.
On the other hand, there should be some way to demonstrate so that the questions we've heard today don't come up that, in fact, all of these inclusion criteria have been met. I would say my view is that's in the too hard box for a committee sitting around the table today but that is something that probably ought to be done. There ought to be operational definitions put on these criteria.
DR. MAISEL: I think it would be helpful for us to provide some guidance as to what -- it seems like we are focused primarily on the right-heart failure definition so maybe we can tease that out a little bit here from some other people about exactly what guidance we could provide about what we would want to see in order to clear someone who is having biventicular failure including late heart failure.
DR. NELSON: In looking at the questions, I guess I'll ask if this is the right place for it but the whole discussion we've had about the neurological complications, I don't see anything, at least on first glance unless it's buried elsewhere, about trying to select individuals who would be at lower risk for that complication going forward. The question is where is that best addressed.
DR. MAISEL: I think certainly we all recognize in the inclusion criteria it would be great to have features that would weed out the patients at highest risk for neurologic complications. I think with 14 patients we are not going to be able to do that here today. When we get to the post-market side of things, we can discuss going forward what data we might want to see in order to help tease that out.
DR. BORER: In answer to your specific question, I think what we were missing today, although we heard it qualitatively from the investigator, was some measure of myocardial performance of the right ventricular myocardium. We heard that the echos -- that despite low pressures the right ventricular free wall didn't seem to be moving very much.
The echo isn't a great tool to measure right ventricular performance with but you've got it. I think that some measure of right ventricular performance, right ventricular stroke work, right ventricular performance relative to the pulmonary pressures and pulmonary resistance would be helpful. If we had any one of those measures in addition to all the other things we've heard about, and the history of edema and ASARCO, whatever, I think everybody would be a lot more comfortable and accepting that biventricular failure existed.
DR. MAISEL: Clyde.
DR. YANCY: Just one short comment. I would just like to make a plea for the importance of clinical judgment in this whole scenario. These are people that are even beyond desperately ill. Sometimes you have to let your clinical intuition guide you.
I'm not sure that we can put -- I greatly respect all the opinions around the table but I think it's going to be very difficult to quantitate some of the things that we're describing and we have to rely on an individual experience with the LVAD population. If an implanting surgeon doesn't feel comfortable that the LVAD is what he or she should do, I would respect that in the patient population of the security and let someone use their clinical judgment.
DR. MAISEL: Jeff.
DR. BORER: I just want to say I agree with Clyde. I mean, I think it's useful and good for us to put some operational definitions on some of these criteria, particularly when many different institutions may be involved. you want to be sure at the end of the day that you know what you've done to whom.
However, having said that, I think that Clyde is absolutely right. It's very difficult. These are very complicated people. They are very sick. I would be a little concerned about being overly -- attempting to be overly precise with objective data.
DR. MAISEL: Okay. I think that's an excellent point. Why don't we move on to the --
DR. ZUCKERMAN: I have one comment on one additional point. It was slide 27 from the sponsor. Do you have any comments about large atrial volumes being another indicator to look at or biventricular failure?
DR. BORER: Well, my opinion would be that as an index that is not unreasonable. Obviously atrial volumes can be large because of several different mechanical factors. But I think as an integrator that is not unreasonable as part of the mix.
DR. MAISEL: Sharon, did you have a comment?
DR. NORMAND: Yes, I raised the issue about the inclusion criteria based on the invalidated probability model so I think that needs to be validated. I suspect all the other criteria are obviously going to weed that out but I think good practice would be to use a scientifically validated model.
DR. MAISEL: Excellent point. Geretta.
MS. WOOD: Does the frequency of any serious adverse event such as neurological or bleeding in table 2.11, adverse event rate, page 21, section 2.3.5, clinical summary raise significant clinical concerns?
DR. MAISEL: Well, this one is an easy one-word answer of yes, it does raise significant clinical concerns but I would be interested in hearing from other people about whether those concerns are dealbreakers or whether we can deal with those safety issues.
DR. SOMBERG: I would just --
DR. MAISEL: Can you speak into the microphone?
DR. SOMBERG: Wouldn't four also be tied in with that?
DR. MAISEL: Sure. Why don't you read No. 4.
DR. SOMBERG: Yes. Could we do that?
MS. WOOD: Considering the bleeding and stroke complication rate seen in the feasibility study, please discuss whether you think that the proposed anticoagulation protocol, page 73, section 3.31, clinical summary, is appropriate for the intended population.
DR. MAISEL: John.
DR. SOMBERG: While I agree, and I think everyone on the panel agrees that there are significant safety concerns, mostly relates to bleeding and thrombosis, the opposite of bleeding obviously, and it seems as though that there really hasn't been a resolution of the problem.
I think the only way you are going to resolve something is not by having each center do a patient specific mode but to try to come up with an approach and then try that approach out. It's best to do it in a randomized controlled study obviously but if one can't do that, at least try an approach.
If one sees a decrease in numbers, it could be by chance here easily but also given a very high problem rate, it certainly would give an indication that one is headed in the right direction. I really think like all great discoveries the team that's put this together has done a remarkable job, but then we come into another problem.
I think there may need to be -- I'll go a little further. To solve this and to do this you are going to need to maybe put together another team to try to deal with some of the bleeding versus thrombosis, the balance of anticoagulation. When to turn it off, how to turn it off, and when to start it again is needed to look at.
It may be solvable and it may not be solvable. I guess the question is going to be is an HDE the right format to try to solve this or are there other more appropriate formats. I don't think anyone has the absolute answer to that but I do think we haven't reached -- specifically we haven't reached the answer but there needs to be a protocol devised but I don't think anyone can adjourn now and write a particle, come back in an hour and give it because it's going to take an awful lot of thought work and bringing new input into the situation.
DR. MAISEL: Chris.
DR. WHITE: I think the bleeding and the strokes are a dealbreaker for me but we'll get to that later. This does remind me of the old days of coronary stents and that is with the coumadin and three antiplatelets agents and the patient bleeds, then you stop the anticoagulation and then the patient clots. You end up swinging back and forth between the two.
These are very old people. The likelihood of being able to use this intensive anticoagulation without having a bleed over months in the hospital is probably close to nil and I think that's what we're seeing in terms of these complications. The problem is the small numbers of patients.
At least in coronary stent work we had large numbers of patients in order to try different regimens to wean ourselves to lesser and less intense anticoagulation regimes. On 14 patients it's hard to make science on the best protocol so I don't have the answer but I think that this intensive regimen is going to lead to more bleeding which leads to stoppage of anticoagulation and leads to more clotting so I don't think that is the solution.
DR. MAISEL: Mitch.
DR. KRUCOFF: Yeah, hopefully we hear more than an echo and I think this is clearly where you need data because what we've got makes it very clear that this is a very narrow bridge in sick patients between what's too much and what's too little. I think John said if you solve this, what happens next in these patients with longer survival is very undefined.
I think we all can recognize that this is a very passionate area where what happens to patients is felt by the patient, by the care team, by the families at such a high level that what happens to everybody else besides your loved one, the other 100 or up to 4,000 people who are treated, I really think this is where we need data.
DR. MAISEL: Acknowledging that this is a very sick patient population with a very high mortality, is there anyone who feels that the safety is acceptable? Jeff.
DR. BORER: Yes, I do. For me it's not a dealbreaker. I have in front of me just to remind me a quotation from the law that says that we have to be able to determine that the device does not expose patients to unreasonable risk of illness or injury. Now, unreasonable is a qualitative term but that is the important word here.
Clearly there were a number of adverse events associated with the use of this device. Some of them I think were probably inherent in the type of disease that the patients came in with when they had the device implanted and some, specifically the strokes and the bleeding events, may have had to do with the management of the device.
Those are disturbing. I wish they didn't happen. They ought to be reduced. The anticoagulation regimen we can't -- as Chris said, we can't judge whether it's appropriate or not appropriate. It's probably not appropriate. It probably has to be improved. But is the risk unreasonable?
I would have to say no because the only way I can judge the reasonableness of the risk is the risk of not doing this and the risk of not doing this, although we'll talk about this I'm sure a little bit later, is if you accept at face value the information we've been given the very high likelihood that all of these patients who were treated will die within 30 days.
I would say that's a worse outcome than living an extra few months having the opportunity, I hate to use this word, to bring closure, to have certain experiences that are meaningful to the patient and the patient's family. And then to have an event occur that predictably can lead rapidly to death rather than long drawn-out periods of suffering.
I don't think this is a show stopper. I think it's disturbing. I think we would like to reduce the risk but I think the risk is acceptable and reasonable in the context of the alternative.
DR. MAISEL: Thank you. Dr. Nelson.
DR. NELSON: I guess although I agree with you in principle, what I find perplexing is there is not a lot of data presented that would allow you, except for a couple of patients, to make that assessment about closure. That may be true as a general point but the question is how much information do we have whether that was true in fact.
DR. MAISEL: Rick.
DR. PAGE: The anticoagulation is not a dealbreaker for me either because I agree. I think the patient population is so sick I'm convinced that the mortality median survival is about two weeks in this population if the procedure is not performed.
On the other hand, I very much wish we had data procedurally in an HDE situation if a regimen were determined and was expected of any enrolling centers could we learn from that and then online evaluate further regimens as time goes on. In terms of under an HDE can there be a requirement for ongoing surveillance of the anticoagulation, for example.
DR. ZUCKERMAN: I think what you -- correct me if I'm wrong -- if the panel does suggest approval of this device in a post-approval setting, could further study of a more uniform anticoagulation protocol be a key element? The answer is yes and we can discuss that. I think that Dr. Borer did read a reasonable definition of safety and I would just be interested in hearing other panel members speak with the data in hand is there reasonable safety.
DR. MAISEL: Norm.
DR. KATO: I'm going to have to agree with Dr. White. If you look at the number of adverse events, it's basically a linear relationship with the number of days that you're alive. I mean, it's a straightline all the way up with no turning back.
I think at this point it is going to be too important to maintain a careful trial atmosphere of this device in order to keep learning. In the history of mechanical assist devices, and particularly the total artificial heart, has been plagued with stroke and bleeding that has been the constant problem for the past 20 or 30 years since it was first devised.
I'm not convinced today that we are that much further along in our understanding. It may require technology in other fields to solve this problem. At this point the adverse event rate seems to me very high and has a linear relationship with the number of days that you're alive.
DR. MAISEL: John.
DR. SOMBERG: Dr. Zuckerman asked the heart of the question here, is the probably benefit risk. I submit to you that we haven't really progressed from this morning's -- in my mine this morning's balance and I fit the sponsor's presentation on this on page 40. I won't hold it up but the scale is here.
They were very honest that four people did not benefit at all. There were four people that I do believe had benefit. The majority of them fall into a zone which I think you would have to spend days to weeks investigating and trying to go back in history and find out if they really benefit even a smidgen from it.
My overall is there is a very thin line here of probable benefit risk that one could take the HT route. One could take other routes that were available to do this. I wouldn't like to see this program end but I certainly don't think this is something for general use. The humanitarian drug exemption is for a very, very small no-alternative population.
I think when one considers that thought should be given. With that said, that's why I think it's so critical to try to develop some sort of program if this was post-marketing approval to try to address the one area that I see to be fixed in some ways and that is to try to balance not going from no anticoagulation to everything that we have in the pharmacologic ombintarian to some place in between and see if we can do that.
When one is dealing with an individual patient, the point I was trying to make but made poorly, was it's very hard to do that because one tends to try to do the best for that particular patient at that moment as opposed to sticking to a protocol, "This is what we do.
Okay, we have to deal with this and we have to deal with that," and go through and see if that approach will work. Now I understand why the agency brought this to the panel because it's such an agonizing thin probable benefit risk situation.
DR. MAISEL: So before we move on to the risk benefit ratio, let's just try to wrap up the safety issue. We haven't heard from a couple people. Dr. Blackstone, can you tell us your thoughts regarding safety?
DR. BLACKSTONE: I have no more to say than what others have said.
DR. MAISEL: Which others?
DR. BLACKSTONE: We've been discussing it most of the day. That is that I think all of us that have worked around devices, especially a device that has four valves in it, large surface areas exposed to blood and the like. This is the chronic problem of biocompatibility we have been faced with for years and years.
I agree with the general idea that more of that you have in the body, the more problems you have. This is a major problem but an expected problem. I don't see that it's that much more than you see in LVADs where you also see an enormous number of events. The number of events here didn't surprise me at all.
DR. MAISEL: George, do you have any comments?
DR. VETROVEC: I guess I fall somewhere on the side of not seeing this as a total dealbreaker. I think what bothers me is approving something for 4,000 patients seems like a lot of patients to figure out I was wrong. We'll have to see what the intermediates are.
DR. MAISEL: Okay. Why don't we move on to the probable benefit section.
MS. WOOD: The study design did not prospectively include a formal measurement of health status. Of the 14 patients enrolled in the Feasibility Study two died in the operating room, 10 did not leave the hospital except for day passes for four patients. One was discharged to a nearby hotel and one was discharged home. Please discuss whether the activities that patients undertook equate to an acceptable quality of life.
DR. MAISEL: We spent some time talking about this as well. We have anecdotal evidence that has been submitted, meeting a grandchild, going out to a movie, spending time with your family, which I think we certainly would all consider quality of life activities.
On the other hand, we don't have any quality of life data from any really validated sources. We've heard that patients were able to complete a questionnaire which I think provides us with some answer about that as well.
Mitch, would you like to comment?
DR. KRUCOFF: I guess my only comment, Bill, because I think we have talked about this a bit, is if you step back we have to recognize in this patient population this is an end-of-life population. Quality of life may be more important than length of life.
Which going back to the anticoagulation and stroke, you know, this is one of the rare areas, at least for me, in devices where it could actually be more important to patients to have a shorter period of time of higher quality life, to actually have a device that made them better even though it might kill them faster than their natural sort of slow, agonizing end. This is a very critical complex area.
Again, I think as challenging as it may be there are enough end-of-life models that this is another area where I really think we have to have data to balance the risks that we have all been talking about in an implantable artificial heart against the value to the human beings and families you are actually involving in this work.
DR. MAISEL: Linda, did you have a comment?
MS. MOTTLE: This has been my main issue is the quality of life and the assessments that we don't see a lot of this longitudinal data here. I also think that can be incorporated within our perspective assessments of these patients which is done in our transplant arena quite regularly. I love the independent assessment review committee.
That is great but we can involve not just the patients and the families but also look at some of the standard tools that are used in the home health arena for getting high-tech patients at home and the evaluation process. I mean, one of the things that bothered me was planning for a patient to go home and yet finding out right before they are ready to go home that the electrical was not adequate.
Using some of these very common assessments for high-tech patients in homes perspectively will eliminate those kinds of issues. I would love to see those built in to this evaluation and long-term.
DR. MAISEL: Sharon.
DR. NORMAND: Yes. I'm having some trouble understanding this as well. I agree with my colleagues that it's a difficult issue to resolve in our minds without any data. I can tell you where I'm coming from. I just don't know if the ability to be told you could go home is very valuable to somebody at the beginning.
Maybe to you or I or somebody else having to stay in a hotel for a while would be really disruptive but maybe to the patients beforehand the ability to think you're going to go home is really, really important. I think we don't have those baseline measurements.
Even though we are seeing some of these things that we think might not be quality of life for sick patients, maybe for these really sick patients these small benefits are huge in their minds and so, again, I'm saying I think there are quality of life benefits here but we don't have them measured.
DR. MAISEL: Norm.
DR. KATO: Well, far be it for me to tell you whether the patients who enrolled in this study had any meaningful improvement in quality of life. I can't do that and no one else can either. I would like to emphasize what Linda said about the outpatient setting. I think there are good models for end-of-life care such as hospice.
This is where I think good data collection can be compared with devices because perhaps, as Sharon said, maybe these people just want to go home and maybe die at home if that was even an option to them. I think the good thing about this type of discussion is that this will finally bring to the forefront many of these issues which really have been lacking in funding and we can get this data to make some decisions about a very difficult time that everybody will face.
DR. MAISEL: Clyde.
DR. YANCY: We are all driven by data and accustomed to looking at data but, again, having some experience in this patient population it is very hard to identify what quality means to the patient because that's really what this question is about.
Again, having lived through this, there are some patients where one more conversation, one more glance, and it may sound trite or may sound less than objective and it's not what we are accustomed to saying but, nevertheless, we can't define that for patients.
I think that becomes very difficult to do. I put this in the context of looking at the issue of safety because it has to do with how much trouble are patients willing to go through to have those moments. I went through the patient before and added up the number of adverse events of people that survived longer than a day.
It averaged to be about 21 serious adverse events. For some patients they will pay that price and others will say no, they won't. I think these are very, very troublesome and I would hate to think that we have to be definitive in this arena because it's highly individualized.
DR. MAISEL: Jeff.
DR. BORER: Yeah, again, I have to agree with Clyde. You know, Sharon will probably want to strangle me when I say this, The numbers are so small but we certainly don't have a dataset here like the datasets we are accustomed to using.
What I see here are a third of the patients almost, between a quarter and a third, big confidence interval so I shouldn't be saying it at all, but, you know, four out of 14 patients had more than five months of life and that is a net increase, I would say, of about four months. We've heard about three of those four and I'm convinced from the anecdotes that we heard that they did have the kinds of experiences that Clyde is referring to.
Now, is that a benefit? I think it certainly is. Is it a benefit that outweighs the inconveniences? Well, I think that it does. But we are grappling here with trying to create or require a dataset of a kind that we are accustomed to looking at when it doesn't exist and, again, referring to this statement of the law.
The law says probable benefit to health outweighs the risk of injury. Probable is not the same as P less than .05 or two trials with P less than .05 which might come close with PMA and certainly the MDA definitions. We have to make a judgment, the best judgment we can.
I am persuaded that for some substantial portion of this extraordinarily sick population there is a benefit of the kind that Clyde has described and that is something that could reasonably be said to outweigh the risk and could be presented to a patient beforehand so that the patient's family could make a choice.
Now, having said all that, do I think we should have more data? Of course I do. So one of the questions that I would have, and I don't know if this is the time to ask it but maybe Bram can explain to us depending what it is that we suggest that the FDA do in terms of HDE or something else, if it were an HDE that were suggested and the FDA chose to proceed in that direction, would it be possible to mandate the obtaining of the additional kinds of data that everybody would love to see?
DR. MAISEL: Well, we will discuss shortly the post-market approval study which we can list as a condition of approval should we decide to head in that direction. Do you have anything to add, Bram?
DR. ZUCKERMAN: Okay. But the short answer is yes if the panel suggest that the bar for an HDE standard of evidence has been met.
DR. MAISEL: Dr. Nelson.
DR. NELSON: I guess I agree with what you've said in responding to Dr. Borer's comments but I struggle over the probable word. The way I interpret that word is what do we think might happen for the next patient? Not what did we think happened to a subset in different ways of the previous 14 and how do we judge that probability, even though I agree it shouldn't be a statistical judgment of P .05.
If I recall, .05 is chance. We hope it's better than that so somewhere in between there how do we judge that? It ties up with this notion of generalizability. At least as I see it, certainly it's feasible but I still struggle in my own mind about probable. Not whether what happened to some is a benefit, I would agree, but how probable is that for the next one, two, three, four, five?
DR. MAISEL: Why don't we move on to question 6 and we can try to put it all together.
MS. WOOD: Please discuss whether you believe the probable benefits of the AbioCor Implantable Replacement Heart outweight the potential risk associated with the device.
DR. MAISEL: So I would like to go quickly around the table and hear from each person. Since Mitch wasn't here yesterday we'll start with him today.
DR. KRUCOFF: Well, on a passion basis I would love to say yes. On a reality basis I would have to say no.
DR. MAISEL: Sharon.
DR. KRUCOFF: Tom, based on what we're looking at with the adverse event rates of bleeding and strokes and no information really on how the patients who suffer those events feel, that the probable benefit to me I can't say clearly outweighs the safety.
DR. MAISEL: Sharon, what are your thoughts?
DR. NORMAND: I may surprise people. I'm struggling on this one. I really don't know at this point.
DR. MAISEL: Chris.
DR. WHITE: I am surprised. I have already said that I'm very concerned about safety. To me the word is probable and I agree with Dr. Nelson, and that is that probable isn't possible. Probable to me actually on rounds is 51 percent, 51 percent likelihood that something is probable. I think probable means more than half the time.
I am concerned that looking at the benefits that were shown in the chart that it's not more than 50 percent of the patients that are likely to benefit. I have a problem with not only the safety but I don't think it's probably beneficial either.
DR. MAISEL: John.
DR. SOMBERG: Like Sharon, I'm agonizing here, too. The situation is a very difficult one so without anymore agonizing, I would say maybe yes, maybe no. If there was a motion on the floor, and I'm not sure we have a motion, but the way I would tend to express my vote is I would vote for approval but it would be a conditional one needing, as I said before, the protocol and a careful analysis of how the company would go forward in terms of centers and finding if there is a way to balance the stroke and bleeding problem towards improving benefit.
DR. MAISEL: Joanne.
DR. LINDENFELD: It's indeed a difficult issue and I think that, again, the issue rests on probable. These patients had a number of complications. If I saw over the course of these 14 patients that I felt certain that things had been changed, the struts clearly were changed but I don't see enough data to make me feel comfortable that the stroke risk has dropped.
If I felt that something had changed substantially going toward more safety risk, then I would feel more comfortable but, at the present time, I don't think it's probable that the next patient will have a benefit from this device. More likely that they would have a major safety issue, so no.
DR. MAISEL: Tom, what are your thoughts?
DR. FERGUSON: In answering the question, I would say that I think the benefits outweigh the risks and I would vote for approval with conditions if we were voting.
DR. MAISEL: Which we will be later. Clyde. We're not voting at the moment. I'm sorry. Let me clarify this. There will be a vote today. We're just -- I'm sorry if that was not clear. There will be a vote today and we're just trying to get a sense of where people are at this moment and what their thoughts are. Clyde.
DR. YANCY: So the way I'll answer this then is to address the two parts separately. I think when you look at the question of probable benefit doing very simple arithmetic, at 30 days 86 percent of these patients were alive.
In the absence of this intervention, there is a reasonable assurance that 70 percent or more would have been dead. I cannot separate myself from my clinical experience. Simply having the chance to maybe make a difference has a pretty high value to me.
On the other hand, the safety issues really concern me because being alive and compromised is a debate that is almost unresolvable. As Joanne mentioned, if we just saw a directional change that show that the adverse events were declining and the stroke issues were getting better, that would affect the balance so I won't commit right now but I think the bar of probable benefit based simply on the numbers I just used, in my judgment, is met. I'm still unresolved on six.
DR. MAISEL: Rick.
DR. PAGE: I agree with Clyde but I also look at the probable term a bit differently. One week of chemotherapy I don't think any of us tell the patient they are probably going to be cured. We can't even say they will probably get better but we are dealing with a terminal illness where we have the chance of making them better and making them significantly better.
I think this probably does offer the patient that chance so I think the potential for benefit is there but our charge is to discuss the risks. In terms of the risk I do not think the risk they are exposed to is unreasonable given the severity of their illness so I would say that indeed the benefit outweighs the risk.
DR. MAISEL: Gene.
DR. BLACKSTONE: I believe based on not only this experience but other experiences with devices because remember for this discussion we can base it on other than the data that we are seeing. I think there is 100 percent chance that people on this device will experience some safety issue and I believe many patients will receive some benefits so I am not so troubled.
I think every patient will experience an adverse response. I think many patients will receive some benefit so I believe there is a positive benefit from this device compared to the general device literature, not just these 14 patients.
DR. MAISEL: George.
DR. VETROVEC: A lot of it comes down to how you define probable. I suspect most people who buy lottery tickets buy them recognizing that they have a lower chance of success than you do with this device and they are at risk of dying. I favor the probable category as benefit because I think they have nothing to be offered to them at that point with less than 30 days. I think going forward they have at least some chance of being better.
DR. MAISEL: Norm.
DR. KATO: To the question at hand, I would vote no. I believe that the probable benefits are less than the potential risks.
DR. MAISEL: Judah.
DR. WEINBERGER: I think I strongly agree with what Dr. Page said. I think that the end of life model that we've inherited from the consideration of cancer patients strongly dictates that we do not demand a 51 percent of the population benefit. As long as there is a measurable benefit to some fraction of the population we offer the therapy to them. Somebody has terminal lung cancer and there's a drug with a 10 percent response rate, they get the drug. In this particular case what we've got to do is to assess whether the alternative of getting the drug is worse than the alternative of not getting the drug.
The alternative of getting this particular drug, which happens to be a device, is a 75 percent chance of a stroke. Well, if the other alternative is 100 chance of death, the way I see it, I think that is a risk that the patient can decide to take. I think the patient should be offered that choice. I'm strongly in favor of saying that the benefits outweigh the risks of this device.
DR. MAISEL: Jeff.
DR. BORER: I won't restate my reasons because you just heard them three times from Rick and George and Judah, but I believe the probable benefit outweighs, as Gene said, the certain risk. I believe the benefit outweighs the risk and, like John, I think that we need to obtain additional information.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Listening to everybody I kind of go this way and that way and this way and that way. Maybe everyone else is, too. Benefit. It's very hard when you think about benefit here and for me to wrap myself around that. I mean, frankly, as a pediatric ICU doc survival to 30 days in my mind if that's all I get is a failure. It may be just a different perspective I have.
Trying to judge survival to 30 days versus, say, survival to hospital discharge, even if you decide that it happened twice in the hotel across the street, depending on what hotel, could well qualify as a good option. It's difficult to say. Not many people survived the hospital discharge. Many people got out to 30 days.
What we're lacking is really information about the quality of that experience in between point A and point B to make any meaningful judgment about the impact of this device on what is, frankly, an experience of dying that is taken from being a two-week experience and turning it anywhere from a less than two week, in two cases, to a 500 day experience. That's why I found myself having a difficult time judging benefit. Now, I'll hopefully wrap this up in a meaningful way but then the question is who should be the judge of that I think is an important question. The comment that Dr. Weinberger made about the family being a judge of it I think is true.
Then the question is what information do you provide them that would help them make that assessment and is this at the point where you, in fact, can take that experience and somehow capture it in a way that can be meaningfully communicated so that they are making an informed choice as opposed to "we don't want to die" choice which everyone will make. I find myself conflicted precisely as I go back and forth around that choice. If I was pushed, and I gather I will be later, I would say I think they have met the possible and feasible. I'm still uncertain about the probable just on the generalizability issue.
Reasonableness is judged against the risks and the notion of suffering a stroke and then living another 30 or 40 days in the hospital doesn't strike me as a sufficient benefit but I'll listen to what other people have to say.
DR. MAISEL: Okay. Thank you very much for all those thoughtful comments. I will weigh in as well which is I am troubled by the safety issues more than anything at this point which we have discussed at length. Why don't we move on to labeling.
MS. WOOD: With regards to the indications for use, labeling and clinical experience, please comment on the following. Do the indications for use adequately define the patient population studied and/or which the device will be marketed.
DR. MAISEL: Why don't you keep going.
MS. WOOD: Are there any additional warnings, precautions, or contraindications that you think should be included in the labeling to assist practitioners in determining the need for biventricular support? Should there be standardized criteria for adequately defining nontransplant candidates?
DR. MAISEL: So we've discussed a lot of these issues at length. The indications for use we discussed at length earlier. I don't think we need to comment specifically on that. The comment regarding transplant or nontransplant, there are transplant centers throughout this country whose job it is to do that. I don't know that we need to have this panel interviewed with that aspect of care.
Regarding additional warnings, precautions, or contraindications, you know, obviously there are issues related to anticoagulation but I don't know that we have any specific warnings or precautions that weren't already listed. Could I hear from other panel members? Sharon.
DR. NORMAND: When I read the material I did have one question. At one point on page 12 of 44 there's an altitude restriction that was 2,500. And then in the patient indication it says 2,000. I just don't know if that was a little fudge factor to protect that amount but there is a discrepancy between the 2,500 and 2,000.
DR. MAISEL: So we would need to resolve the altitude issue which certainly could go into the labeling. Does the sponsor just want to in one word give us the answer? Is it 2,000 or 2,400 for the altitude restriction? 2,500? Is that what you said?
DR. MAISEL: Okay. So 2,500 sounds like the number there. Certainly as has been brought up, I think the patient manual was nonexistent to my eye. I think that is an extremely important aspect of this and is going to need a lot of thoughtful work. Probably a video would be helpful.
Things such as educating patients and their families is going to be a critical component of any of this and that would fall under labeling. Support groups, all of those sorts of things, letting patients, or potential patients and family members talk to both the good and the bad outcome people. Not just the representatives of the best outcomes but a true distribution of what people have experienced would be critically important as well.
Are there any other labeling comments? Yes, Gene.
DR. BLACKSTONE: Yes. I noticed under 7(a) of the indications that if you look at the current indications on page 1 of 20 there is no use of the various scores for this indication which I think is appropriate because I think none of those are validated, should be used.
DR. MAISEL: Certainly we agree with the very low chance of survival at 30 days and we are open to other potential means for assessing that?
DR. BLACKSTONE: I would say the use of any scores to determine that we don't have enough data to use those tools. I think the clinical judgment of the survivability probably, which is not stated, by the way, in the indications.
DR. MAISEL: Bram, did you have a comment?
DR. ZUCKERMAN: Yeah. Could I ask the panel members to go back to the labeling page 11 of 44 to pick up on Dr. Blackstone's point. Dr. Nelson has temporarily left but he asked a critical question previously. Many panel members today have wanted to expand the box of the indications for use.
Dr. Nelson asked is there a way to perhaps make the IFU more narrow to give a better risk benefit profile or just describe who this device is really intended for. Certainly Dr. Blackstone has indicated that the degree of sickness should be better elucidated in this statement. Dr. Borer, would you add anything regarding description of biventricular failure or any other statements?
DR. BORER: Well, I would. I don't know that it's good to take the time of going into very great detail but I would do two things. I would add some specific statement of criteria that need to be met, or at least need to be described if not met, regarding the evidence of biventricular failure and, of course, again, the issue of the scoring system that Dr. Blackstone referred to.
It's not validated but there should be certain criteria that at least are defined and evaluated in order that any future evaluation of this device can be performed in a way that would be more meaningful to everybody than what we have been grappling with here today.
DR. MAISEL: Certainly the indication statement should include something about high mortality. A patient not expected to live, unlikely to live 30 days due to heart failure.
DR. BORER: Oh, sure.
DR. MAISEL: John.
DR. SOMBERG: Bram, I think the HUD is appropriate at this point. I don't think we have data to say that narrowing it would improve things. We have no way to identify who was going to really have a horrendous early adverse event. What I would say is that I did hear that there are a number of other conditions that would be appropriate for this device and the sponsor had listed them, one of which was discussed as a possible massive MI, etc.
My feeling on the panel would be that should not be done through the HDE and that should be done through a separate. Those are a different population. They are not chronically ill so, therefore, in many instances they do better but I think you should study them and you should study them in a separate population. I understand why you would want to do that but that could be a nice control study.
You could get PMA and it could be done in a small population and it wouldn't necessarily be the same as this terribly sick population that you're talking about here. I would not mix apples and oranges and pears and strawberries and all that because you're going to really get a mixed up smoothy.
DR. MAISEL: Yes, Tom.
DR. FERGUSON: Briefly under 2.1 I just have a little problem with the English there. They say an indication for use is those that are not in biventricular failure and not treatable by LVAD destination therapy.
I think that should be reworded because I don't any patient in biventricular failure should be treated with the LVAD. You see the point? This makes it sound like those that can be treated by LVAD can be treated that way. A small point. See what I'm saying?
DR. MAISEL: Rick.
DR. PAGE: I remain concerned about the risk of a stroke which is greatly increased if the anticoagulation is discontinued. Somewhere in here we should put in terms of contraindications any concern or history of bleeding that might preclude intensive anticoagulation and we might get out of this vicious cycle.
DR. MAISEL: We could add the opposite to that as well. Any patient with coagulopathy or the potential for clotting as well. Okay. Any other indications or comments? Yes.
DR. ZUCKERMAN: If I could just try to summarize. Although we don't want to go into great detail writing the IFU right now or draft, there is a precedent with our LVAD destination therapy IFU where we better described the patient population actually studied including the degree of sickness and any significant comorbidity. Also just describe the trial in a clinical section which is not in the IFU right now. Is that appropriate for people in general?
DR. MAISEL: I think that would be fine. Anyone disagree? Okay. Why don't we move on to the training, Geretta.
MS. WOOD: Please comment on the adequacy of the proposed physician training plan as described in the panel package, page 29, section 10, instructions for use. Are there additional recommendations that should be included in the proposed physician training plan or to a transplant cardiologist on the selection of patients?
DR. MAISEL: Does someone want to tackle the training issue? Maybe one of our surgeons. Gene, Norm, Tom?
DR. SOMBERG: I'm not a surgeon but I would say wasn't it felt that this was a little sketchy and that maybe a little bit more information and a more detailed manual would be appropriate for such a complex issue?
DR. MAISEL: The one comment I would have is that there is no mention of actually observing or performing surgery in a human. There were comments about animals but it would seem prudent to have the surgeon if not directly observe -- I mean, I think they should directly observe a procedure in a human.
DR. KRUCOFF: Just one other thing. Obviously you guys have skills from this sort of thoracic modeling virtual presentation and using virtual tools and training would be another way potentially of advancing some of the human side without necessarily going through a human being.
MS. MOTTLE: Sounds like the echo training is critical, too. That may have been mentioned but I missed it.
DR. MAISEL: Yes, Jeff.
DR. BORER: Bill, I just want to second what Mitch has said because while I think it would be wonderful for all the people who might be trained to do this, to observe a procedure being done, my understanding is that there have been 14 of them done in the last four years and that makes it relatively unlikely that any number of people will be able to do this, will be able to observe a procedure in the foreseeable future.
I think having some additional virtual training would be helpful. It's important, I think, to remember that the people who would be trained I would expect would all be transplant surgeons. It's not as if the concepts involved here would be foreign to them.
DR. MAISEL: That being said, this is not an emergent procedure. I don't think it's unrealistic to ask that a surgeon observe a case. They are not going to roll it out to dozens and dozens of centers. Their plan is for 10 centers and I think it would be reasonable to ask them to observe a case. Do other people disagree with that?
DR. SOMBERG: I'm not sure it's needed to observe or whether one of the surgeons whose had experience, in fact, there are two teams that are very experienced, would maybe help a very experienced transplant or LVAD surgeon with his first approach. I think either way you might be -- I know what you're getting at but there are a number of ways to pass on the expertise that has been learned.
DR. MAISEL: Can the surgeons weigh in? I'll call on you if you don't. Tom, what do you think?
DR. FERGUSON: Well, I'm not -- I'm stuttering because I'm unclear as to what the problem is here. Somebody has to mentor the people before they put one of these in and whether you do it at the home base or whether he goes, whether Dr. Gray goes to their place, is that the issue?
DR. MAISEL: Well, the question is whether doing it, mentoring just by classroom experience and laboratory animal experience is adequate or whether --
DR. FERGUSON: No.
DR. MAISEL: -- there needs to be
actual --
DR. FERGUSON: I'm sorry. I misunderstood. That would be totally inadequate in my view. I think there has to be some one-on-one contact in the live operating.
DR. MAISEL: Gene.
DR. KATO: Agree.
DR. MAISEL: Okay. Post-market approval study.
MS. WOOD: Please comment on the proposed plan for post-market data collections submitted by the sponsor, page 67 in the clinical summary. In addition to survival and serious adverse events should data on quality of life or functional status be collected using formal instruments? If so, which instruments would be appropriate?
DR. MAISEL: Well, I think this is one of the easier questions we've had. Undoubtedly there needs to be some post-market data collection on every patient that receives this device in the short-term and really in the long-term. It won't have to be that long probably. Quality of life data is critical to understanding how patients and families are responding to this.
I would not just stop with looking at how patients are dealing with this issue. With regard to which formal instrument should be used, there are certainly well-validated heart failure instruments, I think, any number of which might be acceptable or you could develop your own.
Mitch, do you have any comments?
DR. KRUCOFF: Yes, just two quick points. One, the proposal to follow 20 patients and understanding that 14 patients accrued over four years, I would say why cap it? This is such an important area, complex device. Other things are likely to change over time.
I think this should be an ongoing permanent registration and would encourage the company to leverage something like the STS database or part of a professional society's ongoing longitudinal data collection system so you don't have to bear the full brunt of it. I would thorough encourage the registration of all patients who require this therapy and obviously including quality of life.
DR. MAISEL: I would also comment that on the last page of the sponsor's presentation they said, "This will meet the final phase of the national mission started 41 years ago." I would view this as the beginning rather than the end. I know there's a lot of people who have been working on this for a long time but as a panel member and a physician who takes care of heart failure patients, I would like to see this advance to a PMA someday. This might be the perfect opportunity which is to collect the data you would need to reach that bar in your post-market study.
DR. NORMAND: Yes. I have a comment about the table of adverse event rates in the sponsor's packet about their post-approval study. There may be some typographical errors but the event rates they propose in table 1 that are acceptable are actually higher than the ones that are in the study that we saw. For example, you have TIA listed as .19 but in the study it's .09. You've got respiratory to be .42 but in the study it's .38. You've got to fix those numbers up.
DR. MAISEL: Okay. So clearly the acceptable safety can not be worse than what we have seen in the clinical trial and hopefully with time will get better. Any other post-market comments?
Yes, Gene.
DR. BLACKSTONE: Where I disagree with you, Sharon, is that what we have heard today is there appears to be high early risk that then proceed over time which means the hazard rate is not constant which that table reflects. I think there needs to be far better statistics, Nelson methods or whatever, to look at these event rates.
Then I was about to say the same thing as Mitch said, and that is that the NIH, or whoever, has finally funded, I believe, Alabama for the LVAD registry and maybe this is something that should be tacked on to that registry. At least I heard yesterday that funding had been consummated for that.
DR. MAISEL: Okay. Bram.
DR. ZUCKERMAN: Before getting into the statistical aspects, can we just review what the goals of this registry are? One is just to show the generalizability to other sites, work on the anticoagulation protocol. Also follow these patients out to end of life to look for rare, serious, adverse events. Is that correct or are there other goals?
DR. KRUCOFF: Quality of life projectories.
DR. ZUCKERMAN: Okay.
DR. MAISEL: John.
DR. SOMBERG: I think the major goal in my mind would be to see what the frequency of serious adverse events is. We have a clinical trial and while Dr. Normand is optimistic that we'll see less side effects, we could, as usual, see more side effects when it becomes more generalizable.
I think FDA is going to have to provide considerable surveillance here and there will have to be some discussion about if things progress and there actually are more serious side effects, more CVAs, more bleeding, and no measure of quality of life. There comes a point where things may have to be reassessed.
DR. NORMAND: If I could just clarify. I didn't say that I would see less side effects. I said that the limit they put in was larger than actually seen in the study.
DR. SOMBERG: I stand corrected. When I said that I was sort of tongue in cheek. I apologize.
PARTICIPANT: In that respect, to get a very important continuing dataset the quality of the data needs to be very high in this post-approval study. Hence, I would like to hear some comment on whether there should be an independent neurologist at each site and, two, whether an independent clinical events committee overseeing this type of study would be helpful.
There has been a lot of discussion today questioning the judgment of the site investigator versus the data that we have two or three years later in a panel pack. Would an independent clinical events committee reviewing data at the time of these procedures and subsequent be helpful in clarifying these key data elements.
DR. MAISEL: Gene.
DR. BLACKSTONE: I would suggest the WPNS, which does not require a neurologist but requires certification through Dr. Merkin, and has been widely used in cardiac surgery studies of neurologic events. It's a qualitative score in multiple domains of neurologic function that train nurses, for example, to learn how. I think that would be a valuable adjunct for the neurological part.
DR. MAISEL: Mitch.
DR. KRUCOFF: I think it might be worth just based on the questions, Bram, taking a half step back and saying what is the likelihood of this being executed on a post-market study or registry, the level of quality to really understand what's going on with the device or what is the likelihood of not being able to maintain the quality edges to the data itself or the burden associated with that in the post-market compared to gathering some of that information before market approval.
DR. ZUCKERMAN: Well, let me give you a point to compare against. If this were an LVAD being approved for LVAD destination therapy, the elements that I just mentioned would be included in that type of post-approval study. So is there any reason to expect less with a total artificial heart post-approval study?
DR. MAISEL: George.
DR. VETROVEC: I guess the other question that was brought up to you, Bram, is how often or how does the agency look at this information as it comes in? I guess there's been so much concern about the safety issues here and we are all assuming, hoping that the event rates are going to drop but there have been some people who were skeptical and thought they could go up. How quickly are you going to sense that if that is happening?
DR. ZUCKERMAN: Well, the answer in general is extremely carefully. As you have heard today, the route for device development many times is very different from drug development in that there is an iterative process that needs to be followed carefully.
Hence, the post-approval part of the development of these devices is assuming even greater importance. I would expect that devices of this type would undergo a lot of scrutiny including perhaps coming back to an advisory panel like this if we did see the signals that you are worrying about, George.
DR. MAISEL: Jeff.
DR. BORER: Yes. When you gave your list, Bram, there were two elements that I didn't hear. Maybe I just missed it and John sort of skimmed over it but it was implicit in his answer. I believe that what Gene said is absolutely right. There will be 100 percent incidence of SAEs. There will.
Just capturing the adverse events I don't think is going to be good enough. There does need to be -- this is what I didn't hear you say -- there does need to be an outcome variable other than survival and I think it has to be quality of life and I think there has to be a valid way of measuring that.
In addition to measuring that on the outcome side, there has to be a way of measuring it on the income side, on the entry side, as well as certain other characteristics so that at the end of the day you know as well as you believe you need to know, and we have defined some of the ways we think one should want to know, exactly who the patients were who received these devices.
Maybe that's implicit in the registry that you're talking about and I'm not familiar with the details of the LVAD registry so I don't know what goes in at the entry side but I think there does need to be a series of well-defined characteristics recorded at entry and there needs to be a benefit outcome variable as well as a detriment to outcome variable measure.
DR. MAISEL: John.
DR. SOMBERG: I second the instrument necessity. I don't see a necessity for independent monitoring board. I think the sponsor have been very forthcoming with work here and they are very interested in investigator sites so I think that combined with the FDA may just add another component that doesn't necessarily improve things.
I don't think anyone would object if the FDA thought that was necessary. But it's really important to know the direction of this because there's a lot of people that are sitting on the fence, including myself, and given the severity of the situation we're giving the benefit of the doubt which is not usually the case with the panel, I might say. It's real important to see how things go for the benefit of those who are going to be offered this in the years to come.
DR. MAISEL: Sharon.
DR. NORMAND: We've had recent experience with measurement of quality of life not done by an independent evaluator so I think that's key, especially patients implanted with the device it would be really important to get an independent evaluator of those endpoints both pre and multiple post.
DR. MAISEL: Okay. I think at this point we will conclude our discussion on the questions and move onto the open public hearing session this afternoon. Is there anyone in the audience who wishes to approach and address the panel? Yes.
DR. JARVIK: Hello. I'm Dr. Jarvik. I'm sorry I wasn't able to get here on time this morning. First my plane was canceled last night, and then the locomotive on the train broke, and then the taxi was stopped by the police.
Mr. Chairman, FDA staff, panel members and guests, I have closely followed the AbioCor from its inception decades ago. I have read the AbioCor literature and I have visited some AbioCor patients. The briefing documents for this meeting contain some major discrepancies between the documents prepared by Abiomed and those prepared by the agency.
The documents do not give the orphan division of the FDA specific definition of the subset heart failure patients to whom the humanitarian use designation applies so it's difficult for you to understand that group and it must be a specific subset that I believe has not been clearly defined.
The clinical summary given by Abiomed is very misleading because critical information is omitted. For example, the clinical summary states, "As with all mechanical support devices complications included neurologic events." But Abiomed did not say in that clinical summary that 75 percent of the patients who survived surgery had strokes with a mortality of 50 percent, far higher than with any other implantable blood pump.
AbioCor results are just not comparable with all other mechanical support devices as the clinical summary implies. Abiomed's clinical summary continues, "In contrast to other mechanical cardiac support devices, device related infection was nonexistent due primarily to its full implantability eliminating the special attention needed for exit site care and the risk of infection."
The risks of infection are certainly not eliminated. Two patients died of sepsis and serious infections occurred in every patient except the two who died at surgery. Given other problems related to the size and extensiveness of the surgical trauma in these patients, it is probable that the device was indirectly involved in some of these infections.
Also, Abiomed did not report the extensive length of time that patients were respirator dependent which was months which caused a major reduction in the patient's quality of life. When you add up the time following stroke, you should also look at the time that they were on the respirator and they were sedated.
Abiomed did not report the frequent occurrence of malignant pulmonary hypertension as an adverse event, yet this often occurred with pulmonary artery pressures in excess of 100 millimeters of mercury. I saw this in two patients up to 110 millimeters of mercury.
Many important engineering questions are not addressed at all such as whether alternate pumping contributes to lung damage or whether the high stress of excessive right-sided pressures accelerates device failure. Additionally, Abiomed did not report the occurrence of a major air embolism in one patient who died at surgery. Could patient No. 9, who survived 53 days and never regained consciousness following surgery, also have suffered an air embolism?
Contemporary regulatory principles state that a device is safe when its benefits outweigh its risks. One way to think about risk benefit analysis is to consider not only what makes a device safe but also what makes it unsafe. A device is unsafe when it does more harm than good.
Remember years ago when some physicians first administered new drugs and vaccines to themselves to avoid endangering their patients? Remember the ethical imperative originated by Hippocrates that the physician do no harm? The AbioCor is used in the sickest patients who are weak beyond measure, unable to understand the suffering they will face, and terribly vulnerable.
Informed consent by these desperate dying people is simply not possible. The AbioCor is the largest, heaviest, most complex, most maximally invasive cardiovascular implant ever developed. It impinges on the lungs, liver, stomach, and colon. Implantation requires extensive trauma and exposure to a high surface area of foreign materials which together causes a whole-body inflammatory response with numerous detrimental effects including a severe respiratory distress syndrome.
The AbioCor has much higher rates of death at surgery and death due to mechanical failure than the CarioWest Heartmate or Novacore. All of the patients have suffered with the AbioCor with no benefit for some and scant benefit for the others with the exception of one patient, Mr. Cristerson.
Two weeks ago following a presentation about the AbioCor at the annual ASIO meeting in Washington I asked the audience members to raise their hands if they would consent to have the AbioCor implanted in their own body if it were their only chance of survival.
The room was filled with over 100 experts and circulatory support devices. How many hands would you think went up? Most of them? The answer is one. Only one person raised their hand, a leading advocate of the AbioCor. Dr. Frazier, my long-time friend, dear friend, and colleague, objected to the question. "None of us are actually dying of heart failure," he said, "so we don't know whether we would accept it."
DR. MAISEL: Dr. Jarvik, if I could ask you to conclude your remarks in the next minute or so, please.
DR. JARVIK: Yeah, just a half a page, please. "Yes, dying people do accept it when physicians they trust recommend it." Those of us who are well-informed experts understand that the AbioCor recipients face an extreme ordeal with great suffering. We don't want it for ourselves so how can we recommend it to the patients?
In the course of deterioration from heart failure there will always be a time when it is too late no matter what we do. Knowing this we should intervene sooner or not at all. One minute, please. But we should use much smaller lesson base of artificial hearts, predominately VADs for late class 3 and early class 4 heart failure --
MS. WOOD: I'm sorry, sir. I'm going to have to ask you to wind up. You failed to mention your conflicts of interest before you began speaking.
DR. JARVIK: I'm sorry, ma'am. I have no conflicts of interest. I have no ownership of any company. May I just finish this one last statement? Ask yourselves the critical question. Does the AbioCor do more harm than good?
In the entire field of mechanical circulatory support that has been my career for the past 34 years, I have never witnessed a more clear example of a device that harms the people it intends to help. In my judgment as a medical scientists and as an individual sensitive to my fellow men and women, the AbioCor is unsafe.
DR. MAISEL: Thank you, Dr. Jarvik. Are there any other people in the audience who wish to approach? Yes.
DR. BALTON: I'm Dr. Tim Balton from National Heart, Lung, and Blood Institute. I just wanted to bring up to your recognition, if you don't know already, the NHLVI partnering with the Centers for Medicare and Medicaid Services and the FDA recently awarded a contract to the University of Alabama Birmingham and Dr. Jim Kirkland for a mechanical circulatory support registry.
That is one that is actually following on the heels of the ISHLT registry. There is the potential to use that registry just as discussed here just a few minutes ago for this device. I just want to point that out that there is a tool that is potentially able to be used for that and in the initial phases of designing the datasets for that so there is the potential. I just wanted to make you aware of that.
DR. MAISEL: Thank you very much. Are there any other members of the audience that wish to address the panel? Seeing none, we will close the open public hearing for this afternoon.
Dr. Zuckerman, does the FDA have any additional comments?
DR. ZUCKERMAN: No.
DR. MAISEL: Thank you. Does the sponsor have any additional comments that they would like to make before the vote? Not at this time. Mr. Morton, do you have any comments before we vote?
MR. MORTON: Not at this time, no.
DR. MAISEL: Our consumer rep.
MS. MOTTLE: Thank you. They've been addressed.
DR. MAISEL: Thank you. Geretta, will you please read the voting options.
MS. WOOD: The medical device amendments to the Federal Food Drug and Cosmetic Act amended by the Safe Medical Devices Act of 1990 allows the Food and Drug Administration to obtain a recommendation from an expert advisory panel on designated medical device, humanitarian device exemptions, HDEs that are filed with the agency.
Safety for an HDE is defined as reasonable assurance that the device does not expose patients to unreasonable risk of illness or injury and the probable benefit to health outweighs the risk of injury or illness from its use taking into account the probable risks and benefits of currently available treatments.
Your recommendation for the vote are as follows: Approval if there are no conditions attached. Approvable with conditions. The panel states that the FDA be found approvable subject to specified conditions such as physician or patient education, labeling changes or further analysis of existing data. Prior to voting all of the conditions should be discussed by the panel.
Not approvable. The panel may recommend that the HDE is not approvable if the device exposes patients to unreasonable risk of illness or injury or the probable benefit does not outweigh the risk of injury or illness from its use taking into account the probable risks and benefits of currently available treatments.
DR. MAISEL: So at this point I would like to entertain motions from the panel. Dr. Somberg.
DR. SOMBERG: I move for conditional approval, conditional being the maintenance of post-approval registry of the sorts we have --
DR. MAISEL: First we'll just do approvable, approvable with conditions, or not approvable.
DR. SOMBERG: I move for a motion to approve with conditions.
DR. MAISEL: Do we have a second?
DR. FERGUSON: Second.
DR. MAISEL: Dr. Ferguson seconded. Now we will take conditions one at a time and we will vote on each condition. Dr. Somberg, do you want to go first?
DR. SOMBERG: First, my proposal would be to have a registry as we had outlined in our discussions of the entry, at least of the first 100 patients that have this device implanted. Second, that there be in discussions with FDA a protocol for dealing with the bleeding thrombosis issues.
DR. MAISEL: Okay. We'll take one at a time. Your first condition is 100-patient registry that would include many of the items that we've discussed before. Does anyone -- that is the condition on the table that we will vote upon.
The description of the condition is a 100-patient registry that would include the items that we have previously discussed such as neurologic events, quality of life issues, all of those things that we have previously discussed. Is there a second for that condition? Dr. Vetrovec seconds the condition. Now we will vote on that condition.
DR. BLACKSTONE: Could we have discussion on that?
DR. MAISEL: Okay, yes. Absolutely. Discussion on that condition. Gene.
DR. BLACKSTONE: I disagree with the 100. I think it should be the same as we have just heard from the NIH for dissemination therapy and not limited to the 100.
DR. MAISEL: Okay. So comments about -- Jeff?
DR. BORER: I agree with Gene. I don't see any reason to limit it to 100. I think that we have so few data that it ought to be open-ended.
DR. MAISEL: John.
DR. SOMBERG: Just point of clarification. I'll be glad to modify it. I thought we needed some sort of limit. You're saying with the destination LVAD therapy there was no limit? Is that what I'm hearing?
DR. MAISEL: Maybe we could get clarification from the FDA. Do we need to set a patient limit or can we say all patients need to be in a registry?
DR. ZUCKERMAN: Okay. Generally we design post-approval registries to answer specific questions or to get a feel for safety events or long-term therapy. The post-approval, say, LVAD destination therapy registries would be hypothesis driven coming up with a sample size.
Two, I would remind the panel that although we just heard about a very interesting registry being developed, the sponsor is not obliged to necessarily choose that registry over any existing ones. The real point is that the sponsor and FDA need direction regarding the aims of the registry and just general size but specific numbers aren't going to be that helpful to the agency or sponsor at this point.
DR. MAISEL: So we have obviously spent a lot of time talking about the registry and what it would entail. Dr. Somberg, would you like to retract your motion and try again?
DR. SOMBERG: I'm being pushed in many directions. Some people want things forever, others want no guidance, and some people just put out a single thing. The rationale for why I chose that is I think I would like to see at least a couple of times more than the initial experience. If you could give some direction to where the changes in surrounding therapeutics might aid the situation. You're not going to see that with another 20 which was the sponsor suggestion.
I don't think, you know, if you put -- someone made a derogatory comment to my left that would be 40 years with the 100 so I don't think we're going to wait 40 years to find an answer hopefully. Bram, I'm open to your guidance but I think it should be a substantial number of patients and I would just leave it at that.
DR. MAISEL: Other people who think 100 is -- I guess we're not debating now but other comments from the panel or do you just want to vote on this?
DR. KRUCOFF: I just think we ought to step back and look at the road we're going down because, again, this is not a PMA with data that we are thinking about following up in post-market. This is a clinical experience with 14 patients that we're essentially relying entirely on the post-market registry to sort out, in my opinion, some very complex issues of safety and effectiveness, length of life and quality of life, etc., etc.
I just want to air the perspective, at least, that this is not one set of data that we thought about thoroughly that we are going to follow up in the post-market. This is an HUD with a clinical experience in 14 people that we are talking about entirely relying on the post-market registration to sort out.
DR. MAISEL: John, are you still comfortable with your motion as it is on the table?
DR. SOMBERG: I guess so.
DR. MAISEL: So why don't we vote on this as it is and we'll move on after that. The current amendment on the table is for 100-patient registry with all the factors that we have previously spoken about, neurologic outcome, quality of life, etc. We'll go around the table and vote for this motion or against. Understanding that if we vote against, we can try again.
DR. KRUCOFF: Abstain.
DR. MAISEL: Sharon.
DR. NORMAND: Abstain.
DR. MAISEL: Chris.
DR. WHITE: Abstain.
DR. MAISEL: John.
DR. SOMBERG: For.
DR. MAISEL: Joanne.
DR. LINDENFELD: Against.
DR. MAISEL: Tom.
DR. FERGUSON: For.
DR. MAISEL: Clyde.
DR. YANCY: Against.
DR. MAISEL: Rick.
DR. PAGE: For.
DR. MAISEL: Gene.
DR. BLACKSTONE: Against.
DR. MAISEL: George.
DR. VETROVEC: For.
DR. MAISEL: Norm.
DR. KATO: Against.
DR. MAISEL: Judah.
DR. WEINBERGER: Against.
DR. MAISEL: Jeff.
DR. BORER: Against because I don't want the number but otherwise I would be happy.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Abstain.
DR. MAISEL: So we have six votes against and four votes for so that motion does not pass. Could I entertain another motion? Dr. Blackstone.
DR. BLACKSTONE: Same without the number restriction.
DR. MAISEL: Any other comments?
DR. WEINBERGER: I think that we can envisage a time where stable therapy might be achieved. If we can envision a time where the adverse event rates fall to some acceptable number, we wouldn't need to mandate a continued registry at that point.
If there is a way of envisioning something of the sort, just to throw something out, less than a 10 percent six-month stroke rate, something to say if you can achieve that over 50 patients or over 25 patients, you are absolved from going on with the registry.
DR. MAISEL: Can I ask a point? Bram, if we were to approve a registry, does the FDA have the discretion to end the registry at some point in the future if they decide that the information is no longer needed or valuable?
DR. ZUCKERMAN: Yes.
DR. MAISEL: Okay. So do I hear a second for Dr. Blackstone's motion?
DR. FERGUSON: Second.
DR. MAISEL: Dr. Ferguson. Any further discussion on this motion? Let's vote on this motion for a registry for all patients with the items we've discussed previously.
Dr. Krucoff.
DR. KRUCOFF: Abstain.
DR. MAISEL: Dr. Normand.
DR. NORMAND: Abstain.
DR. MAISEL: Dr. White.
DR. WHITE: Abstain.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: For.
DR. MAISEL: Dr. Lindenfeld.
DR. LINDENFELD: For.
DR. MAISEL: Dr. Ferguson.
DR. FERGUSON: For.
DR. MAISEL: Dr. Yancy.
DR. YANCY: Abstain.
DR. MAISEL: Dr. Page.
DR. PAGE: For.
DR. MAISEL: Dr. Blackstone.
DR. BLACKSTONE: For.
DR. VETROVEC: For.
DR. MAISEL: Dr. Kato.
DR. KATO: For.
DR. MAISEL: Dr. Borer.
DR. BORER: For.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Abstain.
DR. MAISEL: So we have eight votes for and six abstentions. This is just for the registry so that motion passes. Can I entertain another motion for an amendment or condition? Dr. Borer?
DR. BORER: I think that was the second one that John presented about --
DR. SOMBERG: You can say it, Jeff.
DR. BORER: -- about a protocol for anticoagulation.
DR. MAISEL: Can you be more specific?
DR. BORER: I have a different one but the first was what John suggested that there should be a specific protocol devised for this registry when it begins that would define the anticoagulation regimen that should be used.
DR. MAISEL: That's a little varied, I think. I mean --
DR. BORER: I better let John give it.
DR. MAISEL: All right. Why don't we try Dr. Somberg. Why don't you speak for yourself.
DR. SOMBERG: I'm not sure I can be more specific but what I would suggest is there has to be developed a protocol by the sponsor in conjunction with the FDA to deal with the bleeding thrombosis issues. This protocol should try to address the standardized way to mitigate these adverse events.
DR. MAISEL: Do we want to tie that protocol into the indications for use statement at all? Meaning that do you think there should be -- that protocol should be specifically in the instructions for use?
DR. SOMBERG: Absolutely. I think it should be strongly suggested that those who use the device follow the protocol and provide information to the registry so there can be some modification of approach if need be.
DR. MAISEL: So I will try to restate the motion and you can tell me if that is accurate. There should be a specific anticoagulation protocol detail outlined by the sponsor that should be part of the registry. Is that what you're suggesting?
DR. SOMBERG: It's part of the indications for the use of this device and it should deal specifically with the problems of bleeding and thrombosis. It doesn't necessarily have to be anticoagulation.
It may be how much bleeding would be tolerated before one stops anticoagulation, the duration of periods for stopping anticoagulation, etc., because each instance has a risk benefit ratio and we'll see no improvement, as I said before, if everybody goes off and does his own procedure.
DR. MAISEL: I guess I'm not clear on how we would make a judgment about whether this condition is being followed. Are you simply saying that there should be very specific anticoagulation guidelines?
DR. SOMBERG: Yes. I'm saying there should be specific guidelines. Obviously you can't enforce this but you can strongly suggest this. I don't think there is any objection from the sponsor or the developers or the sites that would be using this to try to work in concert. If they worked in sort of an informal basis now, they probably wouldn't mind working in a more formal basis to have a protocol to guide people.
DR. MAISEL: So the motion on the table is that there be specific anticoagulation guidelines included in the instructions for use. Do I hear a second of the motion?
DR. SOMBERG: That went over like a lead balloon.
DR. MAISEL: Seeing no second, why don't we entertain other conditions. Dr. Borer.
DR. BORER: I'll need a little help here to know whether this is a reasonable condition for approvability but since the label for this device presumably can be refined many times over time as more data become available. I think it's important for the FDA to have available to it all the data that it now can have which include the data that I mentioned before about the 14 patients.
That is hemodynamic measures that weren't presented, the evidence that was employed to identify patients as having biventricular failure, whatever that evidence is, clinical judgment, whatever. We need to know that and that we need to attempt to obtain and that information I believe can be obtained from patients' charts, at least in part.
To the extent that we can we attempt to obtain, although it's post hoc now, some information about outcome that would be related to quality of life. It would be very hard to do except by interviewing families. Obviously a long time has passed but I think it should be mandated that the FDA could and should obtain those data.
DR. MAISEL: Can you try to restate that condition in one sentence?
DR. BORER: Yes. As a condition of approvability or of approval I believe that the FDA should mandate that the sponsor provide all available data including those in patient charts that would provide a fuller characterization of the hemodynamic status and basis for inclusion in this trial. And, in addition, any available data related to outcome in terms of quality of life.
DR. MAISEL: Do you mean relative to the 14 patients we've seen?
DR. BORER: I'm sorry. Of course. Yes. I'm sorry. Yes. Relative to the 14 patients we've seen.
DR. MAISEL: Mr. Morton.
MR. MORTON: I certainly understand your interest, Dr. Borer. I think everyone supports that. I just point out this seems to be a precedent that we would be setting as a condition of approval and perhaps as a recommendation to the agency it might be more appropriate.
DR. BORER: I would accept that if that's the way the --
MR. MORTON: Let me try to rephrase Dr. Borer's concern. I think what he is asking for is perhaps in the IFU we have a clinical trial section that adequately describes the clinical trial results. That is a standard part of our IFU. It's not in it right now. It is especially important in this type of situation, if I read Dr. Borer correctly, in that this is a document where we try to be as objective as possible for describing the risk benefit profile of this device. Is that what you are looking for?
DR. BORER: That is exactly what I'm looking for. What I'm grappling with here, if I can just clarify a little bit, is I'm perceiving a distinction between an HDE and a PMA in that admittedly, and acceptably, we don't have nearly as much information for an HDE as we would for a PMA. I'm attempting to develop a mechanism to maximize the information that goes into the directions for use for this device as it comes out now under an HDE. That information probably would have been required for a PMA. That's my problem and I don't know how to verbalize it properly but I think you just did.
DR. MAISEL: So the motion on the table is that the sponsor be required to submit additional information on these 14 patients regarding hemodynamics and quality of life measures. We are not certain that they even have that but is there anyone else who seconds that motion?
DR. PAGE: Second.
DR. MAISEL: So Rick has seconded the motion. Any further discussion? Mitch.
DR. KRUCOFF: Jeff, for 14 patients? You want to go back to the charts on all these people?
DR. BORER: It's all we got.
DR. MAISEL: So we will vote on this motion to require the sponsor to provide additional data on the 14 patients including hemodynamic and quality of life measures, if they have them. Dr. Krucoff.
DR. KRUCOFF: Against.
DR. MAISEL: Sharon.
DR. NORMAND: Abstain.
DR. MAISEL: Chris.
DR. WHITE: Against.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: Against.
DR. MAISEL: Dr. Lindenfeld.
DR. LINDENFELD: Abstain.
DR. MAISEL: Dr. Ferguson.
DR. FERGUSON: Against.
DR. MAISEL: Dr. Yancy.
DR. YANCY: Against.
DR. MAISEL: Dr. Page.
DR. PAGE: For.
DR. MAISEL: Dr. Blackstone.
DR. BLACKSTONE: Against.
DR. MAISEL: Dr. Vetrovec.
DR. VETROVEC: Against.
DR. MAISEL: Dr. Kato.
DR. KATO: Against.
DR. MAISEL: Dr. Weinberger.
DR. WEINBERGER: Against.
DR. MAISEL: Dr. Borer.
DR. BORER: For.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Abstain.
DR. MAISEL: So we have 10 against, two for, and three abstentions so that condition does not pass. I will remind the panel that we talked about a number of other issues related to teaching, indication statements, etc. We will entertain additional conditions if there are any.
Any conditions related to who or where these devices can be implanted? Seeing none, any further discussion? We will vote. So the motion is for approvable with conditions. We've voted for one condition which is a registry of all patients including the parameters we have discussed earlier including neurologic outcome, mortality, and quality of life measures. We will now vote.
Dr. Krucoff.
DR. KRUCOFF: Against.
DR. MAISEL: Dr. Normand.
DR. NORMAND: Abstain.
DR. MAISEL: Dr. White.
DR. WHITE: Against.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: Come back to me, please.
DR. MAISEL: We're going in order and we need your vote.
PARTICIPANT: It's your motion.
DR. SOMBERG: Truthfully it's my motion without the part about the therapeutic protocol so I'm going to vote against.
DR. MAISEL: Dr. Lindenfeld.
DR. LINDENFELD: Against.
DR. MAISEL: Dr. Ferguson.
DR. FERGUSON: For.
DR. MAISEL: Dr. Yancy.
DR. YANCY: Against.
DR. MAISEL: Dr. Page.
DR. PAGE: Can you clarify what we're voting on here?
DR. MAISEL: We're voting on the motion for approvable with conditions with one condition, the registry that we have discussed.
DR. PAGE: For.
DR. MAISEL: Dr. Blackstone.
DR. BLACKSTONE: For.
DR. MAISEL: Dr. Vetrovec.
DR. VETROVEC: For.
DR. MAISEL: Dr. Kato.
DR. KATO: Against.
DR. MAISEL: Dr. Weinberger.
DR. WEINBERGER: For.
DR. MAISEL: Dr. Borer.
DR. BORER: For.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Against.
DR. MAISEL: So we have seven against, six for, and one abstention. The motion does not pass. I will entertain other motions. Does someone want to make a motion for approvable, approvable with conditions, or not approvable? Dr. White.
DR. WHITE: I'll make the motion that this is not approvable.
DR. MAISEL: Do I have a second?
DR. KRUCOFF: Second.
DR. MAISEL: Dr. Krucoff seconds. Any discussion? We will vote. The motion is for not approvable.
Dr. Krucoff.
DR. KRUCOFF: For.
DR. MAISEL: Dr. Normand.
DR. NORMAND: Abstain.
DR. MAISEL: Dr. White.
DR. WHITE: For.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: Against.
DR. MAISEL: Dr. Lindenfeld.
DR. LINDENFELD: For.
DR. MAISEL: Dr. Ferguson.
DR. FERGUSON: Against.
DR. MAISEL: Dr. Yancy.
DR. YANCY: For.
DR. MAISEL: Dr. Page.
DR. PAGE: Against.
DR. MAISEL: Dr. Blackstone.
DR. BLACKSTONE: Against.
DR. MAISEL: Dr. Vetrovec.
DR. VETROVEC: Against.
DR. MAISEL: Dr. Kato.
DR. KATO: For.
DR. MAISEL: Dr. Weinberger.
DR. WEINBERGER: Against.
DR. MAISEL: Dr. Borer.
DR. BORER: Against.
DR. MAISEL: Dr. Nelson.
DR. NELSON: For.
DR. MAISEL: So, once again, seven against and six for. That motion does not pass.
DR. SOMBERG: Mr. Chair.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: I would like to remove for approval with the first approved condition for therapeutic protocol.
DR. MAISEL: Let's take those one at a time. Mitch, do you have a comment?
DR. KRUCOFF: I'm sorry. I'm not sure where we are.
DR. MAISEL: The motion on the table is for approvable with conditions. Is there a second?
DR. FERGUSON: What's different about that?
DR. MAISEL: Well, our conditions are going to need to be different because it appears that more people want approvable with conditions than not.
MS. WOOD: Right now we're voting just on approvable with conditions and then we'll present each condition separately as we usually do for a second and a vote.
DR. VETROVEC: Second.
DR. MAISEL: So Dr. Vetrovec has seconded so we have approvable with conditions and the floor is open for conditions.
DR. VETROVEC: Bram, this is a question of procedure. Can the panel recommend under this condition that rather than being full approval that there be some 100-patient study or something like that with certain specified data as an interim look before making a final decision? Is that a possibility?
DR. ZUCKERMAN: No, that's not a helpful approach because there is a bar that needs to be reached for assessing approvability of the HDE. What the panel has asked today is has the bar been reached or not.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Just as a point of discussion, it strikes me that there are some people who think it's not approvable regardless of conditions. There are some who think it's approvable with conditions but switched back and forth depending on the condition. I'm just wondering if there is any parliamentary process that you might imagine where we could get some clarity on that instead of bouncing back and forth between these motions for the rest of the evening.
DR. MAISEL: Right. So it's apparent that there are not enough votes of not approvable to carry it so approvable with conditions, and someone who voted against the first approvable with conditions needs to tell us the condition that they require in order for it to be approvable with conditions.
DR. SOMBERG: I'll be glad to do that.
DR. MAISEL: But you didn't vote against the first one so it's someone else here who voted against the first approvable with conditions who needs to tell us what condition they want.
DR. SOMBERG: I did vote against it. I'm the one who voted against and I feel morally -- the first time I voted against it.
DR. MAISEL: Okay. So what is the
other --
DR. SOMBERG: I feel very much concerned that if we do not have a unified approach to dealing with the bleeding antithrombotic issues, we will not progress from where we are. I would ask one of the other people who was interested in this area to please accept my need and bring me along so it's done in a parliamentary procedure.
DR. MAISEL: Dr. Weinberger.
DR. WEINBERGER: I think that what you're reacting to is the obvious lack of clarity about how to proceed with anticoagulation. The sponsor doesn't know the answer to this either. I think what you're looking for rather is that all the centers agree up front to anticoagulate in the same fashion with periodic meetings to unify the anticoagulation protocol. Can we mandate such a structure?
DR. ZUCKERMAN: Yes. Dr. Somberg, do you mean to imply in a post-approval study that be part of the protocol?
DR. SOMBERG: Yes.
DR. ZUCKERMAN: And in the IFU just per usual procedure, the anticoagulation that was utilized for these 14 patients will be described. That's the best that can be done.
DR. SOMBERG: I think we can prescribe, and you can tell me if you think I'm regulatorily incorrect but I think we can prescribe that we ask that the sponsor and the FDA meet and try to develop a protocol that people would follow and that would be modified as information comes in which may improve the approach. That's what I would request. The reason for that is if each group takes a separate approach, there will be no forward motion from where we are today.
DR. MAISEL: Can I ask the panel members to please stay in the room? We're in the middle of voting and it will make it very difficult to close the deal on this if there are people that are not here. Would the panel prefer to take a quick break and come back? We have people who are catching flights. I think we're close so, Dr. Zuckerman, did you have something to say?
DR. ZUCKERMAN: Dr. Somberg, so your condition is that in the post-approval study a main goal will be to develop a uniform anticoagulation protocol that will be investigated.
DR. SOMBERG: Develop a uniform anticoagulation protocol that will be applied to the patients assessed to this HDE and then that will permit people to go ahead and evaluate that approach and that approach may be changed over time.
If each one uses a different approach, we will not get any meaningful information on that and I think that is one of the major drawbacks of this particular program we've been talking about. I don't think -- well, anyway, no more editorializing. That's what I want.
DR. MAISEL: Do we have other people who can comment on the anticoagulation issue or condition?
Mr. Morton.
MR. MORTON: Just that I'm a bit confused. As practicing physicians you've got far more experience with this than I. But having done labeling for many devices that require anticoagulation, it's has not been the practice to establish a protocol in the IFU that goes out to multiple centers. It just has not been done. To set some ranges and some expectations and to provide experience that has worked has seemed to be effective. I don't know if I'm missing the point here.
DR. MAISEL: That being said, there have been occasions where the panel has felt very strongly about anticoagulation, the stent population being one of them where we have included in the IFU very specific instructions regarding the type of medications we would expect people on. I agree that I don't recall dose specifics but we certainly have made conditions regarding anticoagulation.
DR. ZUCKERMAN: Okay, but I'm unclear here. I think there are two different issues. Per routine the agency will describe the anticoagulation strategy that was used in these first 14 patients in the IFU without a condition of approval. I thought what Dr. Somberg was asking for was to specifically develop in a post-approval study an anticoagulation strategy that could be developed and investigated along the lines that he just suggested. Is that correct?
DR. SOMBERG: That is correct and the reason for that is that this is different than what we are talking about and what your experience is for PMA where we have a database and we can have a recommendation. Dr. Zuckerman asked me what should be the protocol. At this point I don't really know.
I think we have to bring in, and maybe the sponsor would do that with the FDA, bring in some thrombosis anticoagulant experts to say, "This is what has been done so far and this is what we could do and this is what we are going to recommend to do in the first 20 patients," or something like that, and you would get some feedback on it. That might be what you write into the permanent recommendation. Right now, as I said, we're on the cusp and we have to help this thing along a little bit.
DR. MAISEL: Does the sponsor want to clarify something? I was told that it's okay for you to speak. It's very unusual.
DR. DOWLING: Just a brief adjustment maybe in the recommendation would be that the sponsor working with the investigators and groups of hematologists to form an anticoagulation committee to develop protocols, move forward and follow the patients at different centers to make sure that there is a uniform approach.
DR. MAISEL: Okay. Dr. Somberg, could you please restate your condition?
DR. SOMBERG: I wish I had a staff here of maybe under the Commission for Legal Affairs. I propose that one condition be that the sponsor meet with the FDA to establish a committee consistent with the sponsor and investigators and other consultants in appropriate fields to develop a unified protocol for anticoagulation and to --
DR. MAISEL: Stop there.
DR. SOMBERG: -- evaluated within the post-marketing study.
DR. MAISEL: Okay. Do I have a second for that?
DR. BORER: Second.
DR. MAISEL: Dr. Borer. We have a condition on the table of a sponsor and FDA organized committee to try to unify the anticoagulation recommendations and make it part of the post-market study. Any discussion? So we will vote on this condition. We're not voting on the whole thing yet. Just this condition.
Dr. Krucoff.
DR. KRUCOFF: Do we have a post-market study?
DR. MAISEL: Not yet but we can add another condition.
Dr. Krucoff, we are voting now only on this condition.
DR. KRUCOFF: Abstain.
DR. MAISEL: Dr. Normand.
DR. NORMAND: Abstain.
DR. MAISEL: Dr. White.
DR. WHITE: Abstain.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: For.
DR. MAISEL: Dr. Lindenfeld.
DR. LINDENFELD: Abstain.
DR. MAISEL: Dr. Ferguson.
DR. FERGUSON: For.
DR. MAISEL: Dr. Yancy.
DR. YANCY: Abstain.
DR. MAISEL: Dr. Page.
DR. PAGE: For.
DR. MAISEL: Gene.
DR. BLACKSTONE: For.
DR. MAISEL: George.
DR. VETROVEC: For.
DR. MAISEL: Dr. Kato.
DR. KATO: Abstain.
DR. MAISEL: Dr. Weinberger.
DR. WEINBERGER: For.
DR. MAISEL: Dr. Borer.
DR. BORER: For.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Abstain.
DR. MAISEL: We have seven for and seven abstentions so that motion passes. We'll entertain other conditions such as a registry.
DR. SOMBERG: So move.
DR. MAISEL: Please state your condition.
DR. SOMBERG: That a registry be established to follow the patient's post-approval.
DR. MAISEL: Do I have a second for the registry condition as described previously?
DR. BLACKSTONE: Second.
DR. MAISEL: Dr. Blackstone seconds. Any discussion on the registry? Let's vote.
Dr. Krucoff.
DR. KRUCOFF: Abstain.
DR. MAISEL: Dr. Normand.
DR. NORMAND: Abstain.
DR. MAISEL: Dr. White.
DR. WHITE: Abstain.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: For.
DR. MAISEL: Dr. Lindenfeld.
DR. LINDENFELD: Abstain.
DR. MAISEL: Dr. Ferguson.
DR. FERGUSON: For.
DR. MAISEL: Dr. Yancy.
DR. YANCY: Abstain.
DR. MAISEL: Dr. Page.
DR. PAGE: For.
DR. MAISEL: Dr. Blackstone.
DR. BLACKSTONE: For.
DR. MAISEL: Dr. Vetrovec.
DR. VETROVEC: For.
DR. MAISEL: Dr. Kato.
DR. KATO: Abstain.
DR. MAISEL: Dr. Weinberger.
DR. WEINBERGER: For.
DR. MAISEL: Dr. Borer.
DR. BORER: For.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Abstain.
DR. MAISEL: We have seven for and seven abstentions. That motion passes. Any other conditions? Any other discussion?
DR. SOMBERG: Call the question.
DR. MAISEL: We will now vote on this motion which is a motion for approvable with conditions. Condition 1 is a sponsor and FDA organized committee to unify anticoagulation recommendations and make part of the post-market study. Condition 2 is a registry of all patients that will collect details on the issues we discussed such as mortality and neurologic outcomes and quality of life. That's the motion on the table. We will now vote.
Dr. Krucoff.
DR. KRUCOFF: Against.
DR. MAISEL: Dr. Normand.
DR. NORMAND: Against.
DR. MAISEL: Dr. White.
DR. WHITE: Against.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: For.
DR. MAISEL: Dr. Lindenfeld.
DR. LINDENFELD: Against.
DR. MAISEL: Dr. Ferguson.
DR. FERGUSON: For.
DR. MAISEL: Dr. Yancy.
DR. YANCY: Against.
DR. MAISEL: Dr. Page.
DR. PAGE: For.
DR. MAISEL: Dr. Blackstone.
DR. BLACKSTONE: For.
DR. MAISEL: Dr. Vetrovec.
DR. VETROVEC: For.
DR. MAISEL: Dr. Kato.
DR. KATO: Against.
DR. MAISEL: Dr. Weinberger.
DR. WEINBERGER: For.
DR. MAISEL: Dr. Borer.
DR. BORER: For.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Against.
DR. MAISEL: That is seven, seven. I will vote against this motion as well so it is eight, seven against this motion. The table is clean again.
Dr. Norman, I don't mean to put you on the spot but --
DR. NORMAND: You certainly are.
DR. MAISEL: But you were abstained until this last motion. Can you tell us your thoughts at this point?
DR. NORMAND: I really didn't like the anticoagulant committee idea.
DR. MAISEL: Talk into the microphone.
DR. NORMAND: I didn't like the idea of the committee mostly.
DR. MAISEL: Okay. Is there a motion that you can imagine that you would feel comfortable voting for?
DR. NORMAND: No.
DR. MAISEL: Okay. So I will entertain a motion. At this point I have many people who are asking to take a brief break so we will take a five-minute recess and reconvene.
(Whereupon, at 4:40 p.m. off the record until 4:47 p.m.)
DR. MAISEL: So we've had a lot of discussion. At this point I've had a suggestion which I think is a good one which is that we should vote on whether or not we feel that the submission meets the HDE standard meaning that the device does not expose patients to unreasonable risk of illness or injury and that the probable benefit to health outweighs the risk of injury or illness from its use taking into account the probable risks and benefits of currently available treatments.
Once again, what I would like to do is have a little bit of discussion of there is any, but we don't have to, and then we will vote on whether or not this packet and the presentations today meet the HDE standard, that the device does not expose patients to unreasonable risk of illness or injury and the probable benefit to health outweighs the risk of injury or illness from its use taking into account the probable risk of benefits of currently available treatments.
DR. KRUCOFF: Isn't that what we've been voting on?
DR. MAISEL: What I'm trying to do is clear the bar of HDE recognizing that there are other issues that many of the panel members have that we can't completely agree upon but we have certainly expressed our opinion to the FDA regarding those issues.
MS. WOOD: What Dr. Maisel is trying to say is anyone willing to make a motion that this HDE meets this criteria.
DR. MAISEL: Dr. Somberg has moved. Is there a second?
DR. BORER: Second.
DR. MAISEL: Dr. Borer. So we will vote on whether or not this packet meets the HDE criteria understanding that there are other issues that we have that we have already expressed. Does everyone understand what we're voting on?
DR. KRUCOFF: No.
DR. MAISEL: Dr. Krucoff.
DR. KRUCOFF: I'm sorry. Is this in lieu of approval with conditions or not approvable?
DR. MAISEL: Yes. Yes, it is. This was guidance provided to me by FDA that this would be an acceptable alternative as the panel has had trouble reaching a conclusion.
DR. KRUCOFF: I'm just trying to understand, not to argue. Really what this sounds to me like then is we are running approval versus not approvable.
DR. MAISEL: But we are not voting approvable because we are not saying that there aren't any -- approvable implies there are no conditions. This implies that we are getting a formal vote on whether the panel thinks that we cleared the HDE hurdle but there may be conditions that we cannot agree on. Is everyone clear on what we're voting on?
DR. FERGUSON: Say that again? The HDE hurdle has been overcome with this vote?
DR. MAISEL: We are going to vote on whether or not this submission clears the HDE hurdle recognizing that there may be some conditions that need to be applied to that.
DR. FERGUSON: Thank you. That's helpful. So we are really putting approvable and approvable with conditions versus not approvable.
DR. MAISEL: Yes. So, once again, if you pull out the statement from earlier this morning, you can have that in front of you. I will repeat it one more time and then we will vote. We are voting on does this device -- let me clear the -- is it acceptable as an HDE meaning that the device does not expose patients to unreasonable risk of illness or injury and the probable benefit to health outweighs the risk of injury or illness from its use taking into account the probably risk and benefits of currently available treatments.
Dr. Krucoff.
DR. KRUCOFF: So, again --
DR. MAISEL: Oh, I'm sorry. It has been seconded and we are voting now.
DR. KRUCOFF: Okay. So the move is that this is yes?
DR. MAISEL: The motion is that you are either for this being an HDE or against.
DR. KRUCOFF: Again.
DR. MAISEL: Dr. Normand.
DR. NORMAND: Abstain.
DR. MAISEL: Dr. White.
DR. WHITE: Against.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: For.
DR. MAISEL: Dr. Lindenfeld.
DR. LINDENFELD: Against.
DR. MAISEL: Dr. Ferguson.
DR. FERGUSON: For.
DR. MAISEL: Dr. Yancy.
DR. YANCY: Against.
DR. MAISEL: Dr. Page.
DR. PAGE: For.
DR. MAISEL: Dr. Blackstone.
DR. BLACKSTONE: Against given the information we've been given.
DR. MAISEL: Dr. Vetrovec.
DR. VETROVEC: For.
DR. MAISEL: Dr. Kato.
DR. KATO: Against.
DR. MAISEL: Dr. Weinberger.
DR. WEINBERGER: For.
DR. MAISEL: Dr. Borer.
DR. BORER: For.
DR. MAISEL: Dr. Nelson.
DR. NELSON: Against.
DR. MAISEL: So we have seven against, six for, and one abstention. So the motion did not carry so let's turn around the motion if I can entertain a motion.
DR. ZUCKERMAN: We have the answer.
DR. MAISEL: Everyone says we're done. Dr. Zuckerman, do you have any other comments regarding what we have just discussed or do you need any other points of clarification from the panel?
DR. ZUCKERMAN: I think it would be helpful if you just go around the table asking people for their final assessment of why they voted and what the sponsor can do to get an application into approvable form.
DR. MAISEL: Dr. Krucoff.
DR. KRUCOFF: I voted against and not happily. I think it's obvious through the whole day how torn the need for a device in this space could be, but equally or more the assurance that we are not hurting more than we are helping and where length of life is not the only issue.
In fact, quality of life may be more important to these patients than length of life. Without those data, with as many moving targets and the hardware, the software, the anticoagulation, and zero quality of life data I can't say and I voted against because I don't think the 14 patients presented here convinced me.
DR. MAISEL: Dr. Normand.
DR. NORMAND: I voted the way I did because I don't think there is enough information here. Because we are talking about probable benefit, I didn't want to say let's vote against it. I really feel that it was very difficult and there's not enough information for me to go either way.
DR. MAISEL: Dr. White.
DR. WHITE: I vote against I think for the reasons that were articulated by Dr. Krucuff. I have concerns about the safety and I don't believe the probability of benefit has been demonstrated.
DR. MAISEL: Dr. Somberg.
DR. SOMBERG: I voted for. As I said, I think it is very problematic and is a very difficult area. I think the recommendation would be for the sponsor to go back and see if in that middle group of patients is there any way each chart can be evaluated and possibly shown that there was some quality of life benefit here.
I think it's more important to go forward and to find some mechanism to be able to (a) bear some of the cost and acquire more data to offer patients more quality of life whether it be post-marketing or a new study is going to be needed to really settle most of the issues. Since I did see a probable benefit there, I voted yes.
DR. MAISEL: Dr. Lindenfeld.
DR. LINDENFELD: I voted against because I saw that there are very real risks to this device that are ongoing and I didn't see any evidence that those risks were modified in anyway over the course of the study. I think that in a couple of patients who had the opportunity to have the device again, they turned it down.
They didn't feel it was worth another go at it which said to me they didn't think it was -- maybe they thought it was worth it the first time but it wouldn't be worth it a second time. I just think there are very real risks here and I haven't seen any data at all that we know how to modify those risks.
DR. MAISEL: Dr. Ferguson.
DR. FERGUSON: I voted for principally because I think that at 7:00 this morning we were given certain guidelines about HDEs and I guess I misinterpreted those badly because I frankly think that we are treating a lot of the data that has been presented like this is a PMA. That's all I'll say.
DR. MAISEL: Dr. Yancy.
DR. YANCY: I voted against with some angst. From a clinical perspective I think the bar was met for probable benefit and given the alternative, but from a regulatory perspective even with the definition of HUD, I don't think the bar for unreasonable risk was met. I hope that the sponsor can increase the denominator and I think the directives are clear, paying attention to stroke, bleeding, and quality of life.
DR. MAISEL: Dr. Page.
DR. PAGE: Like Dr. Yancy, I had angst but I nevertheless fall on the side of being in favor of this. I think it has risk that is undeniable but it's in a patient group that is so high risk to begin with that I think it also offers a probable cause that they may receive some benefit. We clearly all would be more comfortable with more data.
DR. MAISEL: Dr. Blackstone.
DR. BLACKSTONE: I, again, reflect the idea that it may be very beautiful engineering, beautiful software, and a lot of effort and time has been expended in that. Much less effort has been made in providing us the data that we need for making these decisions.
DR. MAISEL: Dr. Vetrovec.
DR. VETROVEC: Well, I have all the angst that everyone else has. On the other hand, it's a very high-risk population and I think going forward much will potentially improve. I think it's at that cusp to make the regulatory definition.
I do think one of the problems for us as a panel is that what we probably in our hearts would be much more comfortable with is being able to recommend that we get to see another 50 patients or some number and then make this decision but that wasn't an option and that is one of the difficulties of the question we were asked and I think what was reflected in the votes.
DR. MAISEL: Dr. Kato.
DR. KATO: I voted against. I felt that the adverse events were high in which case the risk was greater than the benefit. I think that going forward there was obviously enthusiasm by the sponsor to consider this device as a bridge to transplant. Perhaps that's where it should be reviewed on a going forward basis for that indication as a PMA.
DR. MAISEL: Dr. Weinberger.
DR. WEINBERGER: I voted for because I think the device has a clear level of promise. I think that clearly we don't know how to manage all the complications to minimize them given the fact that had this been approved it would be available to patients with an IRB approved protocol meaning they would have to consent and understand that this did not show benefit to anybody and did show complications.
I thought that was a level of disclosure that a patient who is dying could come to terms with. I think that it's unfortunate that we are not providing people who are clearly going to be dead with an opportunity basically to continue to provide data as to how to optimize the use of this device.
We have learned over the years for every single device that has been released how to optimize its use and we are not going to learn how to optimize the use of this device without being able to stick our nose forward a little bit.
DR. MAISEL: Dr. Borer.
DR. BORER: I voted for approvability with conditions. I gave my reasons again and again during the course of the day and I won't here. I think if that is not to happen, then the device is still under an ID and, therefore, the sponsors can still operate or undertake to allow operation on additional patients.
You asked what they could do. No. 1, I would do what I suggested earlier, go back and try to get the data. If that exist, try to characterize these patients so that the ambiguity about whether or not they fit into the characteristics of the inclusion criteria could be resolved to whatever extent it can be resolved, which I think might make people judge benefit a little bit differently than they did if they didn't think there was benefit.
I would attempt if it's possible in some way, and I don't want to suggest the ways now because that would take a little creative thinking and it's a little late, but I think it would be useful to attempt to get some information about quality of life changes, though obviously these data need to be obtained retrospectively and posthumously now.
No. 3, I would attempt to find additional patients who would meet inclusion criteria but I would try to tighten up prospectively the definition -- the operational definitions of the inclusion criteria so that everybody can know in some objective way who is included.
I would prospectively define the quality of life measures that I would choose to use to determine whether people did benefit in that way from any additional procedures. I would put the whole package together with all that information and bring it to the FDA again.
DR. MAISEL: Dr. Nelson.
DR. NELSON: I voted against and I would agree with everything that Dr. Borer mentioned about the analysis, the retrospective data set, and just to add to me it would have been helpful to feel that the optimism about going forward is demonstrated in at least a handful of patients. It's not clear to me that the number has to be as high as 50 but at least more than one.
DR. MAISEL: Thank you. I also might mention that the sponsor's plan for what they would do following device approval certainly could be performed under an IDE and expansion out to the other centers and demonstrating that you could perform this procedure safely in the other centers would be
Dr. Zuckerman, do you have any other comments?
DR. ZUCKERMAN: No. Those comments were quite helpful.
DR. MAISEL: Mr. Morton, do you have any comments?
MR. MORTON: As Dr. Zuckerman noted today, this will be my last meeting as the industry representative. It's been a privilege to serve on the panel and thank you very much.
DR. MAISEL: Thank you for your service.
Ms. Mottle, do you have any questions?
MS. MOTTLE: No.
DR. MAISEL: Does the sponsor have any comments they would like to make before we conclude?
MR. MINOGUE: Is this one?
DR. MAISEL: It should be on.
MR. MINOGUE: I just would like to thank the FDA for all their support from the last 20 years before I got here and since I've been here. I would like to thank the panel for an amazing day and a comprehensive review and just point out that all your concerns about control and anticoagulation and quality of care for the patients is 100 percent our intent. What we look at is to your comments, that in the end it gives another tool to the experts. As we see it moving forward, we always expected that your peers, the surgeons, the cardiologists, would always act in the best interest of the patients and that's why we defined it on a 10-center. We have some work to do. Again, I thank you for your time today.
DR. MAISEL: Thank you. Any other comments from the panel? This concludes the recommendations of the panel regarding the AbioCor Implantable Replacement Heart H040006. We are adjourned.
(Whereupon, at 5:04 p.m. the meeting was adjourned.)