Diagnose an Imminent Heart Attack
BILL HEMMER, CNN ANCHOR: We want to get to this medical story right now, and an interesting one, too. More than a million people have heart attacks every year. Nearly half of them die. But now a simple test could be on the way that could help doctors diagnose an imminent heart attack and take steps to prevent it. Details of the new research in the latest issue of the "New England Journal of Medicine" and Dr. Eric Topol of the Cleveland Clinic is one of the authors of that study. He's with us now live in Cleveland, Ohio. Nice to have you, doctor. Good morning to you.</s>DR. ERIC TOPOL, CLEVELAND CLINIC: Good morning, Bill.</s>HEMMER: Part of this process is trying to identify who is an at risk patient. How are you defining that, at risk?</s>TOPOL: Well, the really exciting thing in this field is that we now know the process is inflammation of the artery wall. And so we can use proteins that are indicators of this inflammation process. One of these comes from the white cells and it's called myeloperoxidase and it's been greatly illuminating.</s>HEMMER: Back to the question about at risk, though. How do you know who is and who isn't?</s>TOPOL: OK, so if we can find a patient who has active inflammation, that is, in this case, the white cells are angry and releasing myeloperoxidase, they are at risk for having a crack in the artery wall, developing a heart attack or having sudden death.</s>HEMMER: The current tests you're using today, what do they miss that this one picks up then?</s>TOPOL: Right...</s>HEMMER: Is it that crack in the wall?</s>TOPOL: That's right. The test that's used conventionally is called troponin, which is just a protein that measures whether there's been death of heart cell, muscle cell tissue. We don't have -- we haven't had a test that's been used in the emergency room for patients with chest pain that will tell us whether, very quickly, whether the patient has active inflammation of the artery wall. So this is a whole different slice, a way into the process, a way to zoom in on what's going on in the heart arteries.</s>HEMMER: Based on the studies you've done so far, how much more accurate is it than the tests that have been used?</s>TOPOL: Well, it's quite a bit. That is, compared to patients who have troponin or any other test that we conventionally use today, it's fourfold, a 400 percent increase in risk for those patients who have a high myeloperoxidase protein level. So it's a big deal in terms of how much we can discriminate risk of patients.</s>HEMMER: So back to this at risk definition, then. You have to have the condition, or a part of it, anyway, in order for it to show up on this test. If it shows up, then, what's the recommendation for treating it?</s>TOPOL: Well, what we can say is that patients who otherwise would have been dismissed from emergency rooms or would have been thought to be at low risk, now we have a way to really tell whether these patients might go on and have trouble. So these patients would be admitted and be under much more aggressive preventive strategies so that they won't go on and have a heart attack or have any other bad outcome. And that includes a host of medications and, of course, ultimately recommendations for improved lifestyle, a whole strategy.</s>HEMMER: And, doctor, does this explain, then, how someone can go in for a test and be given a clean bill of health then two weeks later be met with drastic consequences?</s>TOPOL: Exactly. When we did a stress test, that only tells us whether there's a narrowing in the coronary artery, a limitation of blood supply. But now we have these protein tests that will tell us whether or not there is a crack imminent in the artery wall, and that's the sudden, proximate cause of the problem. So, yes, that explains the gap very much.</s>HEMMER: When would this be available, doctor?</s>TOPOL: Within the next year.</s>HEMMER: Within the next year? And would it be available at anyone who would go in for even a routine doctor's appointment?</s>TOPOL: That's a great point. Right now it's going to be for certain in emergency room, hospital settings. And the next chapter of this whole story will be whether this protein and others will be useful in the outpatient setting in healthy people.</s>HEMMER: Doctor, thanks. Don't want to go too far yet, but would you call this revolutionary?</s>TOPOL: It's part of the revolution that's going on as far as using proteins to delineate risk and change therapy for patients with heart disease.</s>HEMMER: Dr. Eric Topol, thanks, at the Cleveland Clinic in Cleveland, Ohio.</s>TOPOL: Thanks, Bill.