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Yamaha designed and manufactured to be a Disklavier piano
Unlike the after-market retrofit systems available for installation into pre-existing pianos, this instrument was designed and manufactured to be a Disklavier piano. The structure and integrity of the piano has not been compromised, in order to incorpora...
Yamaha designed and manufactured to be a Disklavier piano
Unlike the after-market retrofit systems available for installation into pre-existing pianos, this instrument was designed and manufactured to be a Disklavier piano. The structure and integrity of the piano has not been compromised, in order to incorporate the Disklavier record/playback systems. Rigid quality control standards are maintained by having all work performed by hightly skilled factory craftsmen, using components manufactured by Yamaha.
U/L listed
This Disklavier piano is Underwriters Laboratories (U/L) listed. The customer can rest assured that the product is completely safe, when used in a normal and customary manner, regardless of location.
Touch and sound of a real acoustic piano
Using floppy disks as a recording medium, this digital device plays a high-quality acoustic piano during playback, ensuring that tonal irregularities, noise and distortion typically found in audio recordings of a piano, are completely avoided. The owner enjoys hearing the beauty of "true" sound from a high-quality acoustic piano, instead of a "recording" of one.
Optical sensors
Fast and accurate optical sensors ensure that every nuance of even the most demanding performance is recorded, providing faithful playback - time and time again.
Song playback
Can be repeated, randomized between two specified points, or started from a specified point in the song.
A selection of favorite songs
On a disk can be compiled into a sequence program.
Auto Disk Play
For timer-controlled playback.
Built-in metronome
For practice playing and recording.
Edit Mode
The following note parameters can be changed in Note Edit mode: pitch, velocity, length, and timing. Missed notes can be inserted in a song while in Insert mode. Punch-in/punch out recording.
MIDI functions
This instrument has a wide range of MIDI functions that allow recording and playback with an external MIDI sequencer, and Ensemble song composition using external tone generators, synthesizers, etc.
Seasoned for Destination
Yamaha specifically seasons this piano for the U.S. market. The tuning stability, finish and overall musical integrity are enhanced over the long life expected of a fine piano.
Permanent Crown Solid Soundboard
Yamaha utilizes a process that creates a permanent crown in the soundboard at the same time mimimizes soundboard cracking. The customer can feel confident that not only will the piano last for years, but the beautiful sound of a Yamaha piano will last a lifetime.
Solid Spruce Soundboard
At the Yamaha lumber mill and wood processing facility, the finest spruce is quarter sawn; and less than 10% of the total is selected and reserved for Yamaha piano soundboards. Solid spruce, rather than laminated spruce or poplar, is the choice in all fine pianos for the best amplification of sound, best tone and sustain.
Full Length Ribs
Yamaha reinforces the crown in its soundboards by using ribs that continue to the edge of the soundboard, and are glued into the notched liner (or inner rim on the grand piano). Reinforcing the crown ensures that the tone quality will remain for years and years and improves tuning stability.
V-Pro Plate
Yamaha uses V-PRo (Vacuum Shield Mold Process) in casting iron frame (plate). V-Pro plates are stonger and visually more appealing, critical dimensions are produced more accurately than before.
Extruded Aluminum Action Rails
Yamaha engineering developed a unique Extruded Aluminum Alloy Action Rail (bearing a Yamaha patent) that is one of the best innovations for improving a piano action in the last 100 years. The usual fluctuations in wood rails that effect touch, caused by periodic weather changes, are eliminated allowing stable, long-lasting action regulation.
Balanced Action
Each key of a Yamaha piano is individually tested and measured for the corrections needed to obtain uniform "down weight" pressure. Yamaha actions play correctly and uniformly. This balancing helps ensure a lifetime of superior touch and control across the keyboard.
Uniform Key Travel
Yamaha designs all grand and vertical pianos to have the same key travel. Regardless of size, type or model of Yamaha piano, the keyboards will always feel the same.
Spruce keys
Yamaha uses Spruce for the keys on all models of pianos. Spruce is very light and possesses a very high ratio of strength to weight. It is ideal for key construction, even though its cost is greater than either sugar pine or bass wood. Yamaha keyboards respond quickly, providing fast repetition for the most intricate piece of music. Yamaha keyboards withstand heavy use over years of fortissimo passages.
Yamaha Servicebond™ Assurance Program
The Yamaha Servicebond Assurance Program is a service that is provided to the customer, without additional charge, 3-8 months after delivery of their piano. This service is a thorough check up and adjustment procedure to "rejuvenate" a piano after initial play-in and acclimation of the piano to its new environment. It takes the form of a "service policy" that assures the piano will start its life in the home correctly, and after six months or so of settling and becoming acclimatized, will receive the benefit of a service visit to return it to the conditions specified by the manufacturer.
|Remote Control
|Pre-Recorded Pianosoft Sample Disk
|Blank 3.5" 2DD Floppy Disk
|Getting Started and Playback Manual
|Advanced Operations Manual
|How To Care For Your Yamaha Piano Guide
|Tone Generator for the Disklavier. Click here for more information KMU50
|PianoSoft Collection
|An extensive collection of pre-recorded music (3 1/2" diskette) featuring a wide variety of music categories and well-known performers are now available for the Disklavier. Visit Hal Leonard Publishing Please select "PRODUCT SEARCH" on the Hal Leonard ONLINE homepage and enter "pianosoft" in the search field. This software is available from your local authorized Yamaha dealer or by calling Music Dispatch at 1-800-637-2852
Audio & Video
|Depth (Length)
|5' 8" (173 cm)
|40 inches (101cm)
|59 inches (149 cm)
|Net Weight
|715 lbs (325 kg)
|Soundboard Dimension
|1860 square inches
|Speaking Length of #1 bass string
|49.8 inches
|# of backposts
|White Keys
|Acrylic Resin
|Black Keys
|Phenolic Resin
|Duplex Scaling
|Middle Pedal Function
|Soft-Close Fallboard
|Control Unit/ Dimensions
|17-1/8" x 2-5/8" x 8-1/2" (435 x 68 x 217 mm)
|Control Unit/ Weight
|5 lbs. (2.3 kg)
|Control Unit/ Switches
|Power on/off
|Control Unit/ Buttons
|Song Select Rev/ Fwd, Play/ Pause, Stop, Part Select , L/R, Record, Volume, Transpose, Tempo, Repeat, -/NO, 0, +/YES, <> Cursor, Enter, Disk, Metronome, Function/ Edit
|Control Unit/ Controls
|Rotary dial with ring of LED indicators
|Control Unit/ LCD
|24 character, 2 line
|Control Unit/ Song Number Indicator
|7 segment, 2 digit display
|Sensor System/ Key Sensor
|88 key, speed sensing, single-beam optical sensors, Dual key hammer locations, 16 note polyphonic
|Sensor System/ Pedal Sensor
|Sustain- Continuous (half pedal), Sostenuto, Soft (Shift) - Continuous (half pedal)
|Key Drive
|Self-calibrating, long stroke, key-end solenoids
|Pedal Drive
|Trapwork integrated solenoids, Sustain- Continuous (half pedal), Soft/Shift- Continuous (half pedal)
|Song Storage/ Media
|3.5" 2DD floppy disk
|Song Storage/ Capacity
|Max 60 songs (depends on song file size)
|Song Storage/ Disk Capacity
|Song Storage/ Song File Format
|E-SEQ (read and write) Standard MIDI File Type 0 (read only)
|Remote Control/ Buttons
|Record, Part Select, L/R, 0 ~ 9 keypad, Search, Repeat, A-B, Transpose -/0/+, Tempo -/0/+, Rev/ Fwd, Volume -/+, Song Select Rev/ Fwd, Play, Pause, Stop
|Metronome/ bpm
|40 ~ 230
|Metronome/ Time Signature
|1/4, 2/4, 3/4, 4/4, 5/4, 6/4, 7/4, 8/4, 9/4
|Metronome/ Beep
|11 steps: 0 ~ -10
|+/- 24 semitones (2 octaves) in 1 semitone steps
|-50% ~ +20% in 1% steps
|Titles/ Song
|Up to 32 characters
|Titles/ Disk
|Up to 64 characters
|Connections/ MIDI
|MIDI In/ MIDI Out
|Connections/ Foot Controller
|Foot Cntrl
|Power Supply/ Power Requirement
|Local AC voltage
|Power Supply/ Ambient temperature
|5 ~ 40 deg. C (41 ~ 104 deg. F)
Optional Accessories
Songs are played back at the wrong tempo or in the wrong key.
Disklavier / Silent Piano / Hybrid Piano – Removing "Ghost" Files from USB Thumb Drives Using a Mac / Apple Computer
Disklavier, Silent Piano and Hybrid Piano: Removing "Ghost" Files from USB Thumb Drives Using a Mac / Apple Computer


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BabyGirl04's Blog
Sun, Dec 23, 2012 at 2:13 AM
ugh i cant sleep im so board ugh... idk what to do!
Sat, Dec 22, 2012 at 11:18 AM
Finally got an instagram..
I got one finally follow me please.. @__auri__ortiz I will follow back!!
Sat, Nov 24, 2012 at 12:14 PM
Nicki MInaj and Cassie Dating.?
so there have been LOTS of rumors bout Cassie and Nicki dating are they cuz if they are omg that is sooooooooooooooooooooo CUTE
Thu, Aug 9, 2012 at 8:31 AM
I'm so happy school is like 4 days away!!! I just wanna go back already! I wanna see my crush soooo bad when i see her I wanna run up to her and give her the biggest hug in the world!!!!!
Fri, Aug 3, 2012 at 9:08 AM
So I wanted to me as my profile picture but i can't :((( it's cuz my dads all woried bout me or something but :( I wish I could
Thu, Jul 5, 2012 at 8:13 AM
Late 4th of July
Sorry barbs and ken barbs but I was laate I still love you and hope u had a greta 4th of July!!!
Mon, Jun 18, 2012 at 10:31 AM
Hey barbs and ken barbs, I'm not sure if your into thos type of stuff but if you are or what to see for your self go to www.emazinglights.com were you can get rave stuff, use this code to get a free gift and a discount with whatever you buy.! The code is Emp2563 (you must enter it as it is typed) thanks for helping emazing light out and keep team minaj strong.! Iloveyou barbs and ken barbs.!
Thu, Jan 26, 2012 at 11:56 AM
hey guys I hope ur having a good day but im sick ugh! I hate well i hope everyone has a good day i love u!!!!!!!!!!
Sat, Jan 14, 2012 at 6:46 PM
Hey guys what i do!? How are u let me know haha! If my barbz and ken barbz are wondering why i havnt been on here in a while its because I dont have internet at my house so sorry if I dont get back but I love u guys!
Sun, Jan 1, 2012 at 1:15 AM
Nicki Minaj Killed it Tonight!
Nicki minaj did really great with this new year's performance! The song turn me on! Was so great her outfit the best! Her hair pretty! For roman in moscow she made it the best night ever! Nicki I love you!!!

subset: commoncrawl


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RSS Feeds
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Popular Stanford feeds
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Many Stanford websites offer RSS feeds of their content. Click on the RSS icon on any Stanford web page to access the RSS feed.


text: Volunteer anglers are being sought to survey remote ponds and lakes around Maine in search of brook trout. The brook trout pond survey project is a collaborative effort of Trout Unlimited, the Maine Department of Inland Fisheries and Wildlife and Maine Audubon to gather data on ponds in remote areas of northern, western and eastern Maine that are potentially inhabited by trout. The program is now in its third year and aims to identity previously undocumented wild brook trout populations. So far, volunteers have surveyed 161 ponds out of more than 400 that have been identified for the project. Of those, trout have been found in 35 of them. More information and survey forms can be found at www.tumaine.org/brooktrout.htm.


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Divide and conquer space that's not used to its fullest potential with our pantry organizers. First, make sure all of the space on walls and doors is maximized with our space-saving solutions. Shelf organizers help save space and increase the visibility of your pantry shelves.
categoryKitchen Back to Kitchen Pantry Organizers
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35th Glacier Glide race in Whitefish
WHITEFISH, Mont. - No matter the outcome, racers finished the Glacier Glide Nordic Ski race Sunday with a feeling of accomplishment.
"My goal was just to come out and have a good race and have some fun at a nice local race," said Ruben Castren.
"My goal was to have fun and just got out there and do the best I could do, and that's what I did. And I just kept up with the front pack and stayed right in there," said Sylas Schutt.
"I just wanted to do it to do it and see what I could do," said Keelan Gorman.
Ruben tells NBC Montana that he learned to ski when he learned to walk, and he's looking forward to some big events coming up for Nordic skiing.
"There's Junior Nationals in Stowe Vermont in first week of March. Which there's qualifiers, you have to qualify to go to that. Our first qualifier was last weekend. So yeah, hopefully I will be going to that in March."
The winner of the 9k and a top five finisher of the 18k says the key to success is being able to relax.
"Try to stay calm and ski," said Gorman.
"I don't know. Relax, don't really think about it much. Don't want to psyche myself out," said Schutt.
Robin is the event organizer for the Glacier Glide. She also coaches the kids and explains why it's worth it.
"It's so fun to see kids their first time on skies and you know see them improve, see them get excited about skiing and playing games. Just having fun with them out there," said Robin Brooks.
Her sister is Holly Brooks, who earned her spot on the Olympic team for Nordic skiing in Sochi this year.
Robin also has a long history with Nordic skiing and racing.
"I've been skiing my whole life. My parents put me on skies when I was two years old. My dad coached me all the way through high school and I raced in college."
This year was the 35th glacier glide race. The racers were satisfied and the crowd was very supportive.
More Stories
- Copyright ©2016 by KECI, KCFW, KTVM. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
- Greg Gianforte keeps low profile, Montana votes
- US Census estimates show Bozeman population growth
- Contamination in Montana park; highest in kids' sandbox
- Spotty showers, cooler temperatures


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In my spare time, I like to check out scouting reports and thoughtful analysis on the players that our divisional rivals draft.
Today, let's take a look at RG3.
After reading this, I think it's very possible we will see RG3 bail on the Redskins after his rookie contract and possibly play for someone like the 49ers when they finally decide that Alex Smith is in fact not a franchise QB.


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Discussion in 'Pistons and NBA' started by DeetroitDynasty-e, Jun 5, 2007.
The difference is that CB has about 75K on him and he's a Mercedes.
its still the same if the engine blows.
I guess he's a Mercedes with 5 different owners though... and some time in Minnesota, which can really hurt the resale value.
LOL. I guess it's OK as long as I have the maintenance records and a CarFax report.
I didn't know Steve Blake was a FA. Don't get duped, steveblake is a very good penetrating guard, good defense and can shoot the three pointer with pin point accuracy. I watched this guy while at MD, with the Wizards, Portland and Denver, he is an above average passer with good court vision. Litle Earl- he is fast, accurate and can penetrate better than most guards twice his size. I would definitely like this pickup. He torched the pistons and everyone else throughout the league.
I had Steve Blake on my radar screen too. Solid ball handler and passer. Pure point guard.
And very affordable...
I had Blake on my fantasy team and I was quite contend with the stats he had put up- he can shoot the ball pretty good and is decent at assists if given the minutes. Joe D could get him, draft a decent big at #15 and the best player available at #27.
I like Earl Boykins, he plays with heart. When our guys start playing lazy and low energy, he could spark them, he's 31 though, nothing long-term... I do see the league favoring small guards, a la Gibson, Tony Parker and the like.
Whose the most NBA-ready Center-like player in the draft? A guy to backup Rasheed
Are you sure that's your question? Answer: Greg Oden
Haha, good answer... a guy who could potentially fall to us at 15... somebody we dont have to develop... like Oden, but not him, i think he'll go top 10 lol
Jason Smith, Tiago Splitter, Sean Williams. There really is no one you don't have to develop outside of the top 5. Sean is reported as a potential lottery pick but got kicked out for some misdemeanor. questions abound over his character.
I'd take the risk on him at #27, 5.0bpg sits nicely with me.
hells yeah. we're on the cusp of blowing the team up. go for broke on this draft and see if it pans out. if it doesn't I don't know how adding some fringe guy is going to carry this team over the top.
I like that 5 bpg... really i think the direction the league is going, we need a smart, defensive, agile center. Otherwise we'll have a big, constantly in foul trouble, bench-man.
So PG at 15 and C at 27. Sounds right to me. Their is no big man that is good enough to be the 15th pick from what I see (Except for the lottery picks Oden, Durant etc.) Noah has dropped, but he should be top 10 still.
on sean williams
If things don't work out for Chauncey here, Marcus Camby. Pursue Camby. He's not young but he's actually coming off a good year, plus he's that stopper we need in the post.
S $ T Billups..send him to Denver for Camby and Blake or Nene and Blake and JR Smith
Separate names with a comma.


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Hey....great pictures. Just been thinking about all of you. Looks like your trip has been fantastic.
Are you ready to come home yet?
Keep enjoying. Hope to see you soon.
Trip Start Dec 15, 2009
92Trip End Aug 27, 2010
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Where I stayed
An early check-out meant that we were on our way in good time and so had a leisurely drive from Germany into Denmark, stopping just short of the border for a picnic lunch and a nice cold German beer
It was easy enough to find the bed and breakfast and we were very pleased with what we found; the lower part of a lovely house, with bedroom, bathroom, full kitchen and living room complete with ping pong table. Legoland had been on our list of things to see and do in Denmark, but having seen our accommodation, checked the Legoland entry fees, consulted our upcoming itinerary (and considering that the kids went to Legoland in England with Grandma and Grampy last summer) we decided to pass and spend a couple of quiet leisurely days exploring the area around Vejle and generally taking it easy
Unfortunately the first B&B wasn't available for all three nights and so for the second night we had agreed to move our stuff to the apartment of some friends of the B&B owner. The apartment itself wasn't quite as nice as the first B&B, but it was set on the most amazing property with big open areas, a fruit orchard, a small lake and extensive woodlands with numerous walking trails. The kids had a blast playing in the garden, kicking a football around and "rescuing" frogs and so we managed to while away the best part of the day (something we should probably have done more of throughout the trip). We decided mid-afternoon to drive into the town centre to do a little shopping and go for a swim at the local pool, only to discover that everything in Vejle closes at 4pm on a Saturday and so we bought some groceries and returned to the apartment for the evening!
Sunday was our reason for being in Denmark and having spent another lazy day hanging out and moving back to the first B&B it was "show time". The easiest way to get in and out of Horsens from Vejle is by train and so to avoid the traffic jams after the concert we bought a return ticket and made our way, albeit slowly, to the stadium. The lengthy stroll from the train station to the arena took us through the town centre and backstreets, but was an enjoyable walk soaking up the festival-like atmosphere and enjoying the craic
Horsens promised to be the smallest venue on the tour, but the stadium had been expanded for the concert and the standing area was much larger than expected. This would be the first time the kids had been in the standing area for a concert and so we'd planned to be there in good time to get a good spot where they wouldn't get bumped around too much. It seems that about ten thousand Danes had the same idea and by the time Snow Patrol (the Northern Irish support act and another favourite band of ours) hit the stage the standing area was crammed. Snow Patrol were great, witty, and very much on form despite it being their first gig in quite a while (I guess their summer tour was cancelled too).
By the time U2 arrived on stage, Derek had made some new friends who were quite intrigued by our story and the kid's presence at the concert (we didn't spot one other child there the whole time)
A great time was had by all and the concert was a fitting finale for the unofficial end of our travels.
SPOILER ALERT… In case you hadn't noticed the curious nomenclature or this is one of the first entries you've looked at, here's the skinny. As a bit of fun, the name of this blog "Moody 360" takes inspiration from the banner U2 have designated for their World tour "U2 360" and for extra interest and challenge, every blog entry (other than this one) has been given the title of a U2 song (or Album)… we've had some great times trying to make certain titles work and are still trying to figure out how we can use "Alex descends into Hell for a Bottle of Milk" somewhere! Our encore will be almost two more weeks on the road visiting family and friends and having fun, stay posted we're not quite finished yet……


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- Home
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Topic Title
- Comparative Effectiveness of Percutaneous Coronary Interventions and Coronary Artery Bypass Grafting for Coronary Artery Disease
Full Report
- Research Review Oct. 15, 2007
Related Products for this Topic
- Surveillance Report Jun. 25, 2013
Related Topics
Executive Summary – Oct. 15, 2007
Comparative Effectiveness of Percutaneous Coronary Interventions and Coronary Artery Bypass Grafting for Coronary Artery Disease
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Archived: This report was assessed in May 2013 and some conclusions were considered out of date. Findings may be used for research purposes, but should not be considered current.
Table of Contents
Atherosclerosis develops in a patchy, discontinuous fashion within coronary arteries. Therefore, it is possible to treat the discrete areas of obstruction that most impede coronary blood flow to the myocardium. The mechanical approaches to coronary revascularization fall broadly into two categories: coronary artery bypass grafting surgery (CABG) and catheter-based percutaneous coronary interventions (PCI). Together, these coronary revascularization methods are among the most common major medical procedures performed in North America and Europe.
Coronary bypass surgery and coronary angioplasty (with or without stents) are alternative approaches to mechanical coronary revascularization, so their comparative effectiveness in terms of patient outcomes has been of great interest. The comparative effectiveness of bypass surgery and angioplasty is an open question primarily for those patients for whom either procedure would be technically feasible and whose coronary disease is neither too limited nor too extensive.
CABG is generally preferred for patients with left main coronary artery disease or severe triple-vessel disease with reduced left ventricular function because it has been previously shown in randomized trials to improve survival compared with medical therapy. In contrast, PCI is generally preferred for patients with most forms of single-vessel disease when symptoms warrant coronary revascularization, in light of its lower procedural risk and the evidence that PCI reduces angina and myocardial ischemia in this subset of patients.
The choice between PCI and CABG is most relevant for patients whose coronary artery disease (CAD) lies in between these extremes, namely patients with single-vessel disease of the proximal left anterior descending artery (LAD), most forms of double-vessel CAD, and less extensive forms of triple-vessel CAD. Most randomized controlled clinical trials (RCTs) of angioplasty and surgery have been conducted in this middle segment of the patient population with CAD.
The purpose of this report is to evaluate the evidence for the comparative effectiveness of PCI and CABG in this population of patients with CAD. Specifically, the report addresses the following key questions:
Key Question 1a. In patients with ischemic heart disease and angiographically proven single or multi-vessel disease, what is the effectiveness of PCI compared with CABG in reducing the occurrence of adverse objective outcomes and improving subjective outcomes?
Key Question 1b. Over what period of time are the comparative benefits of PCI and CABG sustained?
Key Question 2. Is there evidence that the comparative effectiveness of PCI and CABG varies based on:
- Age, sex, race, or other demographic risk factors?
- Coronary disease risk factors, diabetes, or other comorbid disease?
- Angiographic-specific factors including, but not limited to, the number of diseased vessels amenable to bypass or stenting, vessel territory of stenoses (e.g., left main or anterior descending coronary arteries, right coronary artery, circumflex coronary artery), diffuse vs. focal stenoses, left ventricular function, or prior revascularization procedures?
- CABG-specific factors including, but not limited to, cardiopulmonary bypass mode (normothermic vs. hypothermic), type of cardioplegia used (blood vs. crystalloid), or use of saphenous vein grafts, single or bilateral internal mammary artery grafts, or other types of bypass grafts?
- Clinical presentation (e.g., stable angina or unstable angina based on New York Heart Association functional class I-IV, acute coronary syndrome, cardiogenic shock, acute myocardial infarction with or without ST elevation, or silent ischemia)?
- Adjunctive medical therapies, such as short-term intravenous or oral antiplatelet drugs, or long-term use of oral antiplatelet drugs?
- Process characteristics such as provider volume, hospital volume, and setting (e.g., academic vs. community)?
- Prior PCI or CABG revascularization procedures?
We identified 23 RCTs of PCI vs. CABG that enrolled a total of 9,963 patients. (Descriptions and full names of RCTs are shown in Tables A and B.) The early studies (patient entry 1987-1993) principally used balloon angioplasty as the PCI technique, and the recent studies (1994-2002) principally used stents as the PCI technique. Only one small trial of PCI vs. CABG used drug-eluting stents (Seoul-Hong). The demographic characteristics and cardiac risk factor profiles of trial participants were typical of patients with coronary disease, although only 27 percent of trial patients were women and few trials included patients age 75 and over. Patients with either left main disease, single-vessel disease other than in the proximal LAD, prior CABG, or poor left ventricular function were generally excluded. Among PCI-assigned patients, use of stents and adjunctive medical therapy (e.g., dual antiplatelet therapy) was common in the recent studies but not in the earlier trials conducted when balloon angioplasty was standard. Arterial grafting with the left internal mammary artery was frequently employed in CABG-assigned patients, especially in more recent trials. The quality of most trials was high; all but two trials included randomization methods that were sound and clearly explained, their dropout rates were low, and they performed intention-to-treat analyses.
To assess the extent to which the RCT results are generalizable to the wider population of patients presenting with CAD, we evaluated the results of 96 articles reporting on patients who received either PCI or CABG and were followed in 10 large registries. Overall the quality of the observational studies was high because each enrolled large numbers of subjects who had good followup and adequate descriptions of most key subject characteristics. Among the registries, patients with single-vessel disease were more likely to be selected for PCI, whereas patients with left main or extensive triple-vessel disease or total coronary occlusions were more likely to be selected for CABG.
Short-term/procedural outcomes
For consistency, throughout this document, we present results in the positive frame (e.g., survival rather than mortality, freedom from strokes rather than strokes). We present PCI-CABG survival differences and PCI-CABG differences in freedom from myocardial infarction (MI), stroke, angina, and repeat revascularization such that positive numbers favor PCI and negative numbers favor CABG. Similarly, we present PCI/CABG odds ratios such that ratios greater than 1.0 favor PCI and ratios less than 1.0 favor CABG. In this section, we present the short-term/procedural outcomes which were reported either as "in hospital," "procedural," or "within 30 days" of the procedure. Results were statistically homogeneous unless otherwise noted.
Procedural survival. In randomized trials, procedural survival was high for both procedures and did not differ significantly: PCI-CABG procedural survival difference was 0.1 percent (95-percent confidence interval (CI): -0.3 to +0.6 percent) and PCI/CABG odds ratio for survival of 1.4 (CI: 0.98 to 1.97). There were no significant differences in procedural survival when trials were subdivided into balloon-era and stent-era studies or into single-vessel-disease and multi-vessel-disease patient populations.
In large registries, procedural survival has increased significantly over time. Short-term procedural survival after PCI generally exceeded that of CABG in both earlier and more recent time intervals, however, even after controlling for differences in clinical characteristics.
Freedom from procedural strokes. Freedom from procedural stroke (reported by 16 randomized trials) was significantly higher after PCI than after CABG: PCI-CABG difference in freedom from procedural stroke of 0.6 percent (CI: 0.2 to 1.0 percent, p=0.002) and PCI/CABG odds ratio for freedom from procedural stroke 1.96 (CI: 1.16, 3.3, p=0.01).
Freedom from procedural myocardial infarctions. Freedom from procedural MI was not assessed in a consistent fashion across trials of PCI and CABG, and there was significant heterogeneity in this outcome among the randomized trials. The pooled PCI-CABG difference in freedom from procedural MI was small and not statistically significant.
Long-term outcomes
Survival. Long-term survival across all randomized trials between 1 and 5 years of followup was similar in CABG-assigned and PCI-assigned patients, with less than 1-percent absolute PCI-CABG survival difference at each time point. (PCI/CABG odds ratios ranged from 0.94 to 1.13.) None of the differences was statistically significant.
The long-term survival difference between PCI and CABG was significantly different in the older trials that relied on balloon angioplasty, but not in the more recent trials that employed coronary stents. The 5-year survival was higher after CABG in balloon-era trials (PCI-CABG survival difference -2.1 percent, CI: -4.1 to -0.1 percent, p=0.04), whereas 5-year survival did not differ between the procedures in stent-era trials (PCI-CABG survival difference 1.1 percent, CI: -1.4 to +3.7 percent). Stent-era trials included more patients with single-vessel disease, however, and had shorter followup than balloon-era trials.
In large clinical registries, comparative survival after PCI or CABG varied significantly according to the extent of coronary disease. Survival was significantly better after PCI in patients with single-vessel disease that did not involve the proximal LAD, and survival was significantly better after CABG in patients with extensive triple-vessel or left main disease. In analyses from large clinical registries of patients with middle spectrum CAD severity, there was no difference in survival after PCI or CABG.
Freedom from angina. Freedom from angina was significantly greater after CABG than after PCI in randomized trials between 1 and 5 years post-procedure. (PCI-CABG difference in freedom from angina ranged from -5.0 percent to -8.0 percent; PCI/CABG odds ratio ranged from 0.50 to 0.66, p<0.0001 at 1, 3, and 5 years.)
Freedom from repeat revascularization. Freedom from repeat coronary revascularization was significantly greater after CABG than after PCI. (PCI-CABG difference in freedom from repeat revascularization ranged from -23 to -33 percent, PCI/CABG odds ratios ranged from 0.11 to 0.13; p <0.0001 at 1 and 5 years.) The gap between PCI and CABG in repeat revascularization procedures narrowed in more recent trials that used coronary stents. Nevertheless, patients undergoing PCI with stents required repeat procedures significantly more often than patients undergoing CABG.
Freedom from myocardial infarction. The PCI-CABG difference in freedom from MI was small, less than 1 percent (PCI/CABG odds ratios ranged from 0.87 to 0.92), between 1 and 5 years after the procedure and did not achieve statistical significance at any time point.
Quality of life. Eleven randomized trials reported quality-of-life data using a variety of different measures. In general, quality-of-life scores improved to a significantly greater extent after CABG than after PCI between 6 months and 3 years of followup but equalized thereafter. The degree of improvement in quality of life was correlated with relief of angina.
Cost. The methods of cost determination varied among trials and countries, yet 9 of the 10 RCTs found that the initially lower cost among PCI-assigned patients narrowed substantially over followup. In medium- to long-term followup, PCI-assigned patients had only modestly lower costs (roughly 5 percent) than CABG-assigned patients. This pattern of progressively narrowing cost differences was evident both in trials employing balloon angioplasty and in trials using coronary stents.
Comparative effectiveness by patient demographics
In contrast to the fairly robust evidence concerning overall clinical outcomes, there was much less evidence from randomized trials to gauge whether the comparative effectiveness of CABG and PCI varies according to patient or provider characteristics. Most clinical trials have not reported outcomes in key subgroups, and most have reported only survival, not other outcomes. The most extensively examined subgroup (patients with diabetes) was reported by only 7 of 23 randomized trials. Furthermore, the selection of patients and providers to participate in trials narrowed the range of clinical characteristics and reduced the statistical power to detect variations. For example, most patients in RCTs had preserved left ventricular function, so variations in the efficacy of PCI and CABG according to ventricular function would be difficult to detect. Nevertheless, some conclusions can be drawn from the evidence provided by randomized trials and large registries.
Age. Older patients had more procedural complications from both PCI and CABG, especially stroke. Patients aged 65 years and older had lower long-term survival compared with younger patients. The survival difference between PCI and CABG at 7 years in the BARI trial did not significantly favor CABG in the older patients (-4.7 percent PCI-CABG survival difference) to a greater extent than in the younger patients (-2.8 percent PCI-CABG survival difference). Older patients had more freedom from angina, however, and more freedom from repeat revascularization procedures. The randomized trials enrolled very few patients 75 years of age and over, so conclusions about the comparative effectiveness of PCI and CABG cannot be made for very old patients.
Gender. Roughly 27 percent of the patients in randomized trials were women, and their outcomes were similar to those among men in the trials that examined outcomes by gender. In the BARI trial, women had lower overall survival than men with each procedure, but the PCI-CABG survival difference in women was similar to that in men. In the pooled data from four stent-era trials (ARTS, ERACI-II, MASS-II, SoS), women had clinical outcomes relatively similar to those of men.
Race. Outcomes after PCI and CABG according to race were analyzed only by the BARI trial and registry, which found African-American patients had significantly lower overall survival, irrespective of treatment with PCI or CABG.
Comparative effectiveness by comorbidities
Diabetes. Survival at 1 and 5 years in patients with diabetes was reported by six trials (Figure A). The BARI trial reported a significant survival advantage for patients with diabetes assigned to CABG: 5-year survival of 80 percent with CABG vs. 65 percent with PCI. None of the other trials found as dramatic a difference in survival between patients with and without diabetes. In the EAST trial, for example, the 59 patients with treated diabetes had slightly better survival in the PCI arm at 3 years, equivalent survival at 5 years, and slightly better survival in the CABG arm at 8 years. Among the 62 patients with diabetes in the RITA trial, however, only 2 of the 29 PCI patients died, compared with 8 of the 33 CABG patients. Overall, the survival difference between PCI and CABG was not significantly different among patients with diabetes (Figure A); the pooled PCI-CABG survival difference was -0.8 percent at 5 years, but the confidence limits were very wide, from -8.3 to +6.6 percent (PCI/CABG odds ratio 0.87; CI: 0.51 to 1.49).
Obesity. In general, obesity was not consistently associated with significant differences in comparative effectiveness of PCI and CABG in the two trials that reported outcomes by body mass index. Overall rates of survival, freedom from MI, and freedom from stroke were not affected by body mass index in the ARTS trial. Survival in the BARI trial was decreased in patients with either a very low (<20) or a very high (³35) body mass index.
Other comorbidities. Outcomes according to hypertension, tobacco use, renal dysfunction, and vascular disease were not generally reported by randomized trials.
Comparative effectiveness by angiographic factors
Extent of disease. There was no significant difference in the comparative survival benefit when randomized trials were subdivided into those enrolling patients with single-vessel proximal LAD disease and those enrolling patients with multi-vessel disease (Figure B). In the RITA trial, the survival difference between PCI and CABG was comparable in patients with single-vessel disease and multi-vessel disease (mostly two-vessel disease).
In the randomized trials that enrolled patients with multi-vessel disease, the survival difference between CABG and PCI was greater among patients with three-vessel disease than among patients with two-vessel disease but did not achieve statistical significance. The randomized trials generally excluded patients with extensive coronary disease. Accordingly, comparative efficacy of CABG and PCI according to variations in coronary anatomy could not be fully tested.
In large clinical registries, comparative survival after PCI or CABG varied significantly with the extent of coronary disease, with better survival after PCI in patients with the least extensive coronary disease and better survival after CABG in patients with the most extensive disease.
Left ventricular function. Most trials comparing PCI and CABG randomized patients with relatively preserved left ventricular function and a low prevalence of heart failure. The limited range of ejection fractions within the trials precludes a stringent test of whether the comparative effectiveness of PCI and CABG varies according to left ventricular function. Only the BARI and AWESOME trials reported specific analyses: they found no significant differences in the comparative efficacy of PCI and CABG according to the level of left ventricular function.
Comparative effectiveness by CABG-specific factors
Use of minimally invasive techniques. "Minimally invasive" surgery, which is performed through a small throracotomy incision on a beating heart, was compared with PCI in eight small randomized trials. These trials enrolled patients with single-vessel proximal LAD disease (predominantly or exclusively) and generally used PCI with stents as the comparator. These trials showed no significant differences in survival between PCI and CABG over a relatively short followup period.
Use of internal mammary arteries. Standard CABG was used in all trials that enrolled patients with multi-vessel disease, with variable use of left internal mammary grafting, ranging from a low of 37 percent in the early GABI study to over 90 percent in the more recent ARTS, MASS-II, and SoS studies. In a meta-regression, the 1-year survival advantage for CABG vs. PCI increased along with the proportion of internal mammary artery grafts used, but this trend was not statistically significant and not evident at 5 years.
Comparative effectiveness by clinical presentation
Three randomized trials (ARTS, BARI, and SoS) examined the outcomes of patients according to their clinical presentation. Comparative survival after PCI and CABG was not consistently different between patients with stable or unstable angina. The randomized trials generally excluded patients with acute myocardial infarction, severe congestive heart failure, or cardiogenic shock, so no conclusions about the comparative efficacy of PCI and CABG can be drawn for these patient subgroups.
Comparative effectiveness and use of adjunctive medical therapies
The RCTs did not report comparative effectiveness data based on the use of adjunctive medical therapy for PCI or CABG. It is uncertain whether patients who have undergone CABG are as likely as patients who have undergone PCI to comply with recommendations for long-term use of aspirin, beta-blockers, angiotensin-converting enzyme inhibitors, and statins. There is relatively little evidence on this question from randomized trials; however, the Duke Database, a large observational registry of patients receiving both procedures, reports relatively similar use of evidence-based therapies after PCI and CABG.
Comparative effectiveness and volume-outcome relationship
There was considerable evidence that procedural outcomes of both CABG and PCI were significantly worse in low-volume hospitals and with low-volume operators. This relationship remained significant for PCI, even as procedural risk has been reduced by the availability of coronary stents and adjunctive therapy. While none of these studies were randomized and causality is uncertain, these findings are consistent with a large body of literature demonstrating a relationship between the volume of patients treated and short-term survival for a wide variety of procedures. The magnitude of association of procedural outcomes with volume of PCI and CABG may be only modest, however, at least among sufficiently experienced centers and operators.
Comparative effectiveness and prior revascularization
Most randomized trials excluded patients with prior CABG, but one randomized trial and several clinical registries have compared PCI with re-do CABG in patients with a prior CABG. In the AWESOME trial, 142 patients with prior CABG were randomized to either re-do CABG (75 patients) or PCI (67 patients). While procedural survival was significantly lower in the patients assigned to CABG (92 vs. 100 percent), 3-year survival did not differ significantly. A similar pattern has been reported by large clinical registry studies from Cleveland, Emory, and Kansas City: procedural mortality was higher for re-do CABG than for PCI, but survival at 5 to 6 years of followup did not differ significantly.
Remaining Issues
This comprehensive review of the comparative effectiveness of PCI and CABG identified numerous gaps in evidence that would be suitable for future research. The paucity of published analyses of PCI and CABG outcomes according to patient characteristics strongly suggests the value of a collaborative pooling of individual patient-level data from the randomized trials to (a) enhance statistical power to identify subgroup effects and (b) reduce publication bias by including data from all trials. A collaboration of four stent trials (ARTS, ERACI-II, MASS-II, and SoS) has pooled 1-year outcomes and provided useful short-term analysis in key subgroups. The planned extension of this collaborative pooling to include 5-year followup data should be very informative.
A more extensive collaborative study to pool individual patient data from both balloon-era and stent-era trials would provide additional advantages. First, the number of patients and outcome events would be greatly increased, thereby improving statistical power even further in patient subgroups. Second, more direct assessments of the impact of stents on the comparative effectiveness of PCI and CABG would be feasible, as well as assessment of whether relative efficacy changes over extended followup.
Further research on the association of procedure volume with outcome should examine additional outcome measures, both short term (e.g., nonfatal myocardial infarction, completeness of revascularization) and long term (e.g., survival, angina relief, freedom from repeat procedures), preferably in large patient cohorts using contemporaneous CABG and PCI and applying the same analytic methods. Development of evidence-based process measures for PCI and CABG would facilitate efforts to improve quality of care and might provide better performance measures than procedure volume. However, research is required to understand the relative ability of structural measures (e.g., volume) and process measures to predict institutions or physicians with low-quality CABG and PCI outcomes.
Further clinical trials are also needed to assess whether the availability of drug-coated stents has affected the comparative efficacy of PCI and CABG. Such trials are particularly warranted, as pooled studies suggest that rates of survival and MI are not different between bare metal stents and drug-coated stents over medium-term followup. Recent safety concerns about drug-coated stents emphasize the need for extended followup and trials large enough to detect clinically meaningful differences in outcomes. Furthermore, the procedural risk of CABG in large registries has also declined progressively over time, indicating that both CABG and PCI methods continue to evolve. Several trials to compare contemporary CABG with PCI using drug-coated stents, including the large FREEDOM (NCT 00086540) and SYNTAX trials (NCT 00114972), are currently underway and should be complete in 2012.1
1 NCT numbers are National Clinical Trial numbers, which the National Institues of Health assigns to trials for tracking purposes.
Full Report
This executive summary is part of the following document: Bravata DM, McDonald KM, Gienger AL, Sundaram V, Perez MV, Varghese R, Kapoor JR, Ardehali R, McKinnon MC, Stave CD, Owens DK, Hlatky MA. Comparative Effectiveness of Percutaneous Coronary Interventions and Coronary Artery Bypass Grafting for Coronary Artery Disease. Comparative Effectiveness Review No. 9. (Prepared by Stanford-UCSF Evidence-based Practice Center under Contract No. 290-02-0017.) Rockville, MD: Agency for Healthcare Research and Quality. October 2007.
For Print Copies
For print copies of Comparative Effectiveness of Percutaneous Coronary Interventions and Coronary Artery Bypass Grafting for Coronary Artery Disease: Executive Summary. No. 9 (AHRQ Pub. No. 08-EHC002-1), please call the AHRQ Publications Clearinghouse at 1-800-358-9295 or e-mail email@example.com.
Table A. Brief overview of reviewed randomized controlled trials
- Angioplasty versus Minimally Invasive Surgery Trial
- A small United Kingdom trial of 100 patients with single-vessel proximal LAD disease conducted 1999-2001. Reeves BC, Angelini GD, Bryan AJ, et al. A multi-centre randomised controlled trial of minimally invasive direct coronary bypass grafting versus percutaneous transluminal coronary angioplasty with stenting for proximal stenosis of the left anterior descending coronary artery. Health Technol Assess 2004 Apr;8(16):1-43.
- Arterial Revascularization Therapies Study
- A large European trial of 1,205 patients with MVD that used bare metal stents. One of four trials that participated in the pooling project of stent trials.
- Serruys PW, Unger F, Sousa JE, et al. Comparison of coronary-artery bypass surgery and stenting for the treatment of multivessel disease. N Engl J Med 2001 Apr 12;344(15):1117-24.
- Angina With Extremely Serious Operative Mortality Evaluation
- A medium-sized U.S Department of Veterans Affairs trial of 454 patients with medically refractory angina, high procedural risk, and single- or multi-vessel disease.
- Morrison DA, Sethi G, Sacks J, et al. Percutaneous coronary intervention versus coronary artery bypass graft surgery for patients with medically refractory myocardial ischemia and risk factors for adverse outcomes with bypass: a multicenter, randomized trial. Investigators of the Department of Veterans Affairs Cooperative Study #385, the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME). J Am Coll Cardiol 2001 Jul;38(1):143-9.
- Bypass Angioplasty Revascularization Investigation
- Large U.S.-Canadian trial of 1,829 patients that used balloon angioplasty and reported extensively on outcomes in patient subgroups. Extended followup to 10 years has been reported.
- The Bypass Angioplasty Revascularization Investigation (BARI) Investigators. Comparison of coronary bypass surgery with angioplasty in patients with multivessel disease. N Engl J Med 1996 Jul 25;335(4):217-25.
- Coronary Angioplasty versus Bypass Revascularisation Investigation
- Large European trial of 1,054 patients with MVD that used balloon angioplasty and had limited followup.
- CABRI Trial Participants. First-year results of CABRI (Coronary Angioplasty versus Bypass Revascularisation Investigation). Lancet 1995 Nov 4;346(8984):1179-84.
- Emory Angioplasty versus Surgery Trial
- A medium-sized, single-center U.S. trial of 392 patients with MVD that used balloon angioplasty and reported extended followup to 8 years.
- King SB, 3rd, Lembo NJ, Weintraub WS, et al. A randomized trial comparing coronary angioplasty with coronary bypass surgery. Emory Angioplasty versus Surgery Trial (EAST). N Engl J Med 1994 Oct 20;331(16):1044-50.
- Argentine Randomized Trial of PTCA versus CABG in Multi-Vessel Disease
- A small Argentine trial of 127 patients with MVD that used balloon angioplasty and had limited followup.
- Rodriguez A, Boullon F, Perez-Balino N, et al. for ERACI Group. Argentine randomized trial of percutaneous transluminal coronary angioplasty versus coronary artery bypass surgery in multivessel disease (ERACI): in-hospital results and 1-year follow-up. J Am Coll Cardiol 1993;22(4):1060-7.
- Second Argentine Randomized Trial of PTCA versus CABG in Multi-Vessel Disease
- A medium-sized trial of 450 patients with MVD conducted by the same Argentine group that organized ERACI-I. The trial used bare metal stents and was one of four trials that participated in the primary data pooling project.
- Rodriguez A, Bernardi V, Navia J, et al. for ERACI II Investigators. Argentine Randomized Study: Coronary Angioplasty with Stenting versus Coronary Bypass Surgery in Patients with Multiple-Vessel Disease (ERACI II): 30-day and one-year follow-up results. J Am Coll Cardiol 2001 Jan;37(1):51-8.
- German Angioplasty Bypass Surgery Investigation
- A medium-sized German trial of 359 patients with MVD that used balloon angioplasty and has reported the longest followup of any PCI-CABG trial (13 years).
- Hamm CW, Reimers J, Ischinger T, et al. A randomized study of coronary angioplasty compared with bypass surgery in patients with symptomatic multivessel coronary disease. German Angioplasty Bypass Surgery Investigation (GABI). N Engl J Med 1994 Oct 20;331(16):1037-43.
- Groningen
- A small, single-center Dutch study of 100 patients with single-vessel proximal LAD disease randomized to either stent implantation or minimally invasive bypass surgery.
- Drenth DJ, Veeger NJGM, Winter JB, et al. A prospective randomized trial comparing stenting with off-pump coronary surgery for high-grade stenosis in the proximal left anterior descending coronary artery: three-year follow-up. J Am Coll Cardiol 2002 Dec 4;40(11):1955-60.
- Lausanne
- A small, single-center Swiss trial of 134 patients with single-vessel proximal LAD disease that used balloon angioplasty.
- Goy JJ, Eeckhout E, Burnand B, et al. Coronary angioplasty versus left internal mammary artery grafting for isolated proximal left anterior descending artery stenosis. Lancet 1994;343(8911):1449-53.
- Leipzig
- A small, single-center German study of 220 patients with single-vessel proximal LAD disease that compared bare-metal stents with minimally invasive CABG.
- Diegeler A, Thiele H, Falk V, et al. Comparison of stenting with minimally invasive bypass surgery for stenosis of the left anterior descending coronary artery. N Engl J Med 2002 Aug 22;347(8):561-6.
- Medicine, Angioplasty, or Surgery Study
- A small, single-center Brazilian trial that used three treatment options for patients with single-vessel proximal LAD disease. (Only outcomes in patients assigned to PCI or CABG were used in this report.)
- Hueb WA, Bellotti G, de Oliveira SA, et al. The Medicine, Angioplasty, or Surgery Study (MASS): a prospective, randomized trial of medical therapy, balloon angioplasty or bypass surgery for single proximal left anterior descending artery stenoses. J Am Coll Cardiol 1995;26(7):1600-5.
- Second Medicine, Angioplasty, or Surgery Study
- A medium-sized Brazilian trial of 408 patients with MVD conducted by the same investigators as the MASS-I trial. This study used bare-metal stents and was one of four trials that contributed to the primary data pooling project for stent trials.
- Hueb W, Soares PR, Gersh BJ, et al. The Medicine, Angioplasty, or Surgery Study (MASS-II): a randomized, controlled clinical trial of three therapeutic strategies for multivessel coronary artery disease: one-year results. J Am Coll Cardiol 2004 May 19;43(10):1743-51.
- Myoprotect I
- A small, single-center German trial of 44 high-risk patients with left main or left main equivalent disease randomized to PCI supported by retroinfusion of the anterior cardiac vein or to bypass surgery.
- Pohl T, Giehrl W, Reichart B, et al. Retroinfusion-supported stenting in high-risk patients for percutaneous intervention and bypass surgery: results of the prospective randomized Myoprotect I study. Catheter Cardiovasc Interv 2004;62(3):323-30.
- Octostent
- A medium-sized Dutch trial of 280 patients with single-vessel or multi-vessel disease comparing coronary stents with off-pump bypass surgery.
- Eefting F, Nathoe H, van Dijk D, et al. Randomized comparison between stenting and off-pump bypass surgery in patients referred for angioplasty. Circulation 2003 Dec 9;108(23):2870-6.
- Poland
- A small, single-center Polish trial of 100 patients with single-vessel proximal LAD disease, comparing coronary stenting with minimally invasive direct coronary bypass grafting.
- Cisowski M, Drzewiecki J, Drzewiecka-Gerber A, et al. Primary stenting versus MIDCAB: preliminary report �� comparison of two methods of revascularization in single left anterior descending coronary artery stenosis. Ann Thorac Surg 2002;74(4):S1334-9.
- Randomised Intervention Treatment of Angina
- A large United Kingdom trial of 1,011 patients with single-vessel or multi-vessel disease comparing balloon angioplasty with bypass surgery.
- Henderson RA, Pocock SJ, Sharp SJ, et al. Long-term results of RITA-1 trial: clinical and cost comparisons of coronary angioplasty and coronary-artery bypass grafting. Randomised Intervention Treatment of Angina. Lancet 1998 Oct 31;352(9138):1419-25.
- Seoul-Hong
- A small, single-center Korean trial of 189 patients with proximal LAD disease comparing treatment with DES to MIDCAB.
- Hong SJ, Lim D-S, Seo HS, et al. Percutaneous coronary intervention with drug-eluting stent implantation vs. minimally invasive direct coronary artery bypass (MIDCAB) in patients with left anterior descending coronary artery stenosis. Catheter Cardiovasc Interv 2005 Jan;64(1):75-81.
- Seoul-Kim
- A small, single-center Korean trial of 100 patients with proximal LAD disease comparing treatment with BMS to MIDCAB.
- Kim JW, Lim DS, Sun K, et al. Stenting or MIDCAB using ministernotomy for revascularization of proximal left anterior descending artery? Int J Cardiol 2005 Mar 30;99(3):437-41.
- Stenting versus Internal Mammary Artery study
- A small European trial of 123 patients with isolated proximal LAD disease comparing coronary stenting with MIDCAB.
- Goy JJ, Kaufmann U, Goy-Eggenberger D, et al. A prospective randomized trial comparing stenting to internal mammary artery grafting for proximal, isolated de novo left anterior coronary artery stenosis: the SIMA trial. Mayo Clin Proc 2000;75(11):1116-23.
- SoS
- Stent or Surgery
- A large European-Canadian trial of 988 patients with MVD comparing coronary stenting with CABG. One of four trials that contributed to the individual data pooling project for stent trials.
- SoS Investigators. Coronary artery bypass surgery versus percutaneous coronary intervention with stent implantation in patients with multivessel coronary artery disease (the Stent or Surgery trial): a randomised controlled trial. Lancet 2002 Sep 28;360(9338):965-70.
- Toulouse
- A small, single-center French study of 152 patients with single-vessel proximal LAD disease comparing balloon angioplasty with bypass surgery.
- Carrie D, Elbaz M, Puel J, et al. Five-year outcome after coronary angioplasty versus bypass surgery in multivessel coronary artery disease: results from the French Monocentric Study. Circulation 1997;96(9 Suppl):II-1-6.
a Strength of evidence was based on predefined criteria, as defined by the GRADE methodology.
Abbreviations: CABG=coronary artery bypass grafting; CI=confidence interval; MI=myocardial infarction; PCI=percutaneous coronary intervention; RCT=randomized controlled trial.
Abbreviations: BMS=bare-metal stent; CABG=coronary artery bypass grafting; DES=drug-eluting stent; LAD=left anterior descending artery; MIDCAB=minimally invasive direct coronary artery bypass grafting; PCI=percutaneous coronary intervention; PTCA=percutaneous transluminal coronary angioplasty.
|Key Question
|Strength of evidencea
|Summary, conclusions, and comments
|Key Question 1a. Comparative effectiveness objective outcomes and subjective outcomes: Short-term outcomes
|Procedural survival
|Freedom from procedural stroke
|Freedom from procedural MI
|Key Question 1a. Comparative effectiveness objective outcomes and subjective outcomes: Long-term outcomes
|Freedom from angina
|Freedom from repeat revascularization
|Freedom from myocardial infarction
|Quality of life
|Key Question 1b. Sustainability of comparative effectiveness
|Freedom from angina
|Key Question 2a. Comparative effectiveness by demographic factors
|Key Question 2b. Comparative effectiveness by comorbidities
|Other comorbidities
|Key Question 2c. Comparative effectiveness by angiographic factors
|Extent of disease
|Left ventricular function
|Use of stents
|Key Question 2d. Comparative effectiveness by CABG-specific factors
|Use of minimally invasive techniques
|Use of mammary arteries
|Key Question 2e. Comparative effectiveness by clinical presentation
|Clinical presentation
|Key Question 2f. Comparative effectiveness by adjunctive therapies
|Adjunctive therapies
|Key Question 2g. Comparative effectiveness by process characteristics
|Process characteristics
|Key Question 2h. Comparative effectiveness by prior revascularization
|Prior revascularization
Figure A. Comparison of survival among patients with and without diabetes at 5 years
Figure B. Comparison of single (SVD) with multi-vessel (MVD) survival at 1 and 5 years


text:
Spam mutates, and the Internet community mounts an immune response
Brian Hayes
The techniques used to combat spam are much better known than the methods of spam senders, for the simple reason that authors of spam-fighting tools publish in the open literature. The antispam measures are quite diverse (which is surely a virtue). There are blacklists and whitelists and even graylists, and various schemes to authenticate senders. There have also been many proposals for legal or economic remedies, or changes to network protocols. But the most widespread tactic for thwarting spam is filtering—analyzing the content of individual messages in an effort to distinguish unwanted from wanted messages. Insiders call them spams and hams.
When procmail rule sets became too unwieldy, attention turned to filters based on ideas from computational learning theory. Underlying this approach is the insight that people can tell at a glance whether a message is spam or ham, but they cannot always articulate the reasons behind their judgment or give clear criteria that can be applied to future messages. Thus an efficient division of labor is to let the human reader serve as final arbiter of what is spam and what is ham, while letting the program discern which features of messages are most useful in defining the two categories. Interestingly, the features identified by the software are often ones that human readers don't notice at all.
Initially, a filter program can be trained on a corpus of pre-classified messages. Thereafter, training continues as the human user corrects any errors of classification.
The first experiments with trainable spam filters were reported in the late 1990s. Patrick Pantel and Dekang Lin of the University of Manitoba built a program called SpamCop, and another project based on similar principles was undertaken by Mehran Sahami of Stanford University and Susan Dumais, David Heckerman and Eric Horvitz of Microsoft Research. The idea attracted a lot more attention four years later when it was rediscovered by Paul Graham, an independent writer and programmer, who issued a manifesto titled "A Plan for Spam." Since then, dozens of commercial products and open-source programs have come into use.
The buzzword associated with these projects is Bayesian, after the 18th-century cleric and mathematician Thomas Bayes; in some cases it is further qualified as naive Bayesian. The nature of the e-mail is inferred from a statistical weighing of various features. In this context a feature might be anything from the presence of the word "Viagra" to the number of exclamation points in a message. Given a set of preclassified messages, it is straightforward to tabulate the frequency of each such feature in each class and thus to calculate the probability that a feature will appear in a spam or ham message. Bayes's theorem offers a mathematical armature for making the inverse calculation: Given the presence or absence of certain features in a message, determine the probability that the message is either spam or ham. The naive variant makes the simplifying assumption that all the features are independent.
A filtering program starts by breaking a message down into a sequence of tokens, which could be words or numbers or perhaps special entities such as components of e-mail addresses. During the training phase, each token is entered into a database and assigned a "spamminess" score. In the simplest case the spamminess could just be the token's frequency in spam messages divided by its frequency in all messages, but in practice various minor adjustments are made.
When the filter is applied to a newly arrived e-mail, each token from the message is looked up in the database. The spamminess scores of these tokens make a prediction about the status of the new message. But the predictions may be contradictory. How do you choose which ones to believe, and how do you combine them to reach a decision? Some of the early filtering programs included information from all the tokens, but later authors found that accuracy improved when the program considered only those tokens with the most extreme spamminess scores (close to 0 or close to 1). As for how to combine the values, Graham adopted the formula
where a and b are the spamminess predictions of two tokens. (The formula can readily be extended to an arbitrary number of tokens.) This is not quite the formula suggested by the Reverend Bayes; Graham neglects to adjust for differences in the overall probability of spam and ham. Nevertheless, the filter performs remarkably well.
In a way, what's most impressive about this technique is how crude and superficial is it—and yet it works. There is no attempt to divine the meaning of the message. The filter's judgment is based on weighing a multitude of tiny features, like the minutiae of fingerprints. The basic technology of Bayesian text classification was first developed for more general tasks, such as the automated filing, sorting and indexing of documents. Spam filtering is just a special case of this method, but an unusually difficult one, if only because it's an adversarial process: There's someone out there trying to fool the filter.
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A person who enjoys fowl language, or the use of vulgar words such as cunt or cock. Also these people prefer using there last name rather then the first, because it is less pleasing.
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by Anthony April 28, 2004
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Jefferson City Public Schools must pay more to insure substitute teachers
Under the Affordable Care Act, the district must find $150,000 to insure teachers
JEFFERSON CITY, Mo. - Jefferson City Public Schools announced during Monday night's board meeting it would have to find additional money to insure some of its teachers.
In a story ABC 17 News first reported on Tuesday, the district will have to come up with approximately $150,000 to insure substitute teachers under the Affordable Care Act. District officials say they knew this would happen, but did not know how much it would cost.
The district will have to pay approximately $6,000 per substitute unless JCPS caps their hours below 28 hours per week, which is something district officials say they will not do. Under the Affordable Care Act, the district must provide benefits to anyone who works more than 28 hours a week.
"It would be strange to say, 'you can work Monday through Thursday, but we're going to bring in another sub every Friday,'" said Jason Hoffman with JCPS. "It's just not the best way educationally."
If the district does not comply with the law, it could face millions of dollars in fines from the federal government. Officials say they will not do that. Rather, they will pay the $150,000 or hire a contractor.
"Just putting it into perspective, it's about three teachers," said Hoffman. "A beginning teacher makes about $35,000 and with benefits, we pay about $50,000."
As for which option is best, that's something the board will decide in January.
"Our analysis has come up with, is that it's about a wash to continue doing it on our own or pay that extra benefit or to contract it out to Kelly Services, and then it comes down to quality," said Hoffman.
Several Missouri cities, including Springfield, Columbia and Hallsville, all use the contractor Kelly Services, which comes recommended.


text:
Keith Nolan:
Deaf in the military
Keith Nolan always wanted to join the United States military. The challenge: He is Deaf, which is an automatic disqualification according to military rules. In this talk, he describes his fight to fight for his country. (In American Sign Language, with real-time translation.)
Similar topics
- TEDx
- Disability
- Global issues
- Military
This talk was presented to a local audience at TEDxIslay, an independent event. TED editors featured it among our selections on the home page.
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If you are into chick lit you're going to absolutely love Jill Mansell's Don't Want to Miss a Thing. It has it all - the handsome man-about- town who suddenly finds himself in sole charge of an 8-month-old girl, a small country town, cute girl next door, a husband playing away, a tall dark stranger looking for love, a teenage girl with a bad-boy boyfriend, gossiping villagers and much more.
All the ingredients for a good old-fashioned love story ... or two. Don't Miss A Thing is an entertaining light-hearted read that leaves readers smiling for days to come.
The British author is famous for her many chick-lit books, which have sold more than five million copies.
I asked her some questions.
What's the secret to great chick lit?
I don't really know what the secret to great chick lit is, but my aim is always to create characters I love and care about, because engaging with the reader is so important to me.
A book can be brilliantly plotted and perfectly written, but if I don't care what happens to the people I'm reading about why would I want to read to the end? If I'm not bothered about them, I'll give up.
Do you mind your books being referred to as chick lit?
I don't mind because I'm used to it by now. I prefer romantic comedy as the description of my genre, but even that isn't ideal - dramatic and serious events happen in my novels, along with the comedy.
Basically I write a feel-good version of real life, with all that entails. Also, my characters are of all ages, which tends not to happen in chick lit. I wouldn't want a 70-something lady to think she might not want to read my books because they're all about young people - they're not. And writing about older characters is one of my favourite things to do. My readers ages range from 15 to 95 and I like it that way. There's something for everyone in my books.
Tell us about a typical day when you are in the middle of writing a book?
I recently commissioned an artist (Rose Popay) to paint me writing my books, so here's my typical day - you can see exactly where I sit in our living room, on the sofa with my fountain pen and writing pads, with my timeline next to me - it's a long strip of paper covered in multicoloured sticky Post-it notes describing details of the plot to keep me from straying from the story. That's my daughter sitting at the table behind me - Lydia types up my handwritten pages and gleefully corrects any mistakes I make.
I generally write from nine until five and always have the TV on while I'm working, to keep me entertained and stop the room being too quiet.
I aim to produce 1000 words a day, but that can vary a lot. The last part of the book is the easiest - it feels like skiing downhill, because I know the characters well by that stage and want to see them have their (almost-always) happy endings.
Oh yes, that is a bear standing in the fireplace. Don't worry, he's not real.
Do deadlines have a huge impact on your writing?
I write one novel a year, so just have the one major deadline. If I don't get the book finished I know it creates difficulties for the publishers, so I try really hard to stick to it. Otherwise they might decide to take on a more reliable author and I'd hate that to happen.
When you begin a novel, how far in do you get before you know if it's going to work?
I'm very lucky in that I've never had to delete anything major. I have some writer friends who have done this and I shiver on their behalf - it must be so traumatic to realise your book isn't working and it needs to be chopped.
On occasions I've got a bit stuck and wondered what on earth is going to happen next, but the joy of writing fiction is that you are in charge and you can make anything happen.
You're the queen of your own world and you can make your characters do whatever you like.
How did you become a writer?I was working as a clinical neurophysiology technologist in a hospital when I happened to read a magazine that had been left in the patients' waiting room. Inside was a feature about ordinary unwealthy women like me who had become hugely wealthy bestselling novelists. It was one of those life-changing moments - I suddenly wondered if I could do the same.
So I signed up to join a local evening class in creative writing and began my apprenticeship, writing humorous articles about my own life and selling them to magazines.
I tried to write Harlequin/Mills and Boon-style romance novels, but they were rejected by the publishers because there was too much humour in them.
Try as I might I couldn't seem to leave the humour out, so I switched to romantic comedy instead - and it worked. Many years later, Don't Want to Miss a Thing is my 24th novel.
What's the best thing about being a famous author?
Without a doubt it's hearing from people who tell me that reading my books has got them through hard times.
A teenager who is being badly bullied at school and treats my books as her friends ... or a mother nursing her daughter through a terrible illness ... or a widow who thought she would never smile again after her husband died.
I've had so many lovely messages from people in such situations who have been cheered up by my books and that is the very best reward of all.
And the worst?
Okay, this isn't really the worst thing, but it gave me a clue as to the extent of the power I can sometimes have.
I know that women have changed their lives as a result of reading my books and feeling empowered enough to leave their horrible partners - this is a good thing.
But I did see one woman writing on a blog that she'd moved from a city to a lovely little village in the Cotswolds purely because my books always made it sound so brilliant. Except she'd arrived there to discover there were no handsome men, it was really boring and she was hating every minute.
What's next for you?
As long as I can do it I'll carry on writing. I'm rubbish at anything else.
We have a copy of Jill Mansell's Don't Want to Miss a Thing to give away. Send your name and contact details to firstname.lastname@example.com by March 7.


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|Project Name:
|Access for Young Women
|Project Contact:
|Susan Matloff-Nieves, (718) 592-5757
|Mailing Address:
|Queens Community House
Youth Services
108-25 62nd Drive
Forest Hills, NY 11375
Queens Community House (QCH) is a not-for-profit settlement house serving the Borough (County) of Queens in New York City. We are requesting a grant for our model gender equity program, Access for Young Women (AFYW). AFYW will enable 60 secondary school low-income immigrant young women, who are at risk for non-completion of high school, to achieve proficiency in mathematics and science as measured by the New York State Regents' Examinations. The participants and comparison group will be students at a small alternative high school founded this year by QCH for students who are at least a year behind in high school credit accumulation and from a large high school where we conduct supportive services to students at risk of dropping out due to attendance. AFYW will engage the young women as leaders and advocates for gender equity, while providing academic and social supports.The year-round program will operate at the schools. The young women will:
- Conduct research on gender equity and education issues;
- Address stress and social barriers to women's achievement;
- Apply mathematical and scientific principles to real-life problems;
- Explore careers and college programs with particular emphasis on math and science;
- Study math and science content with teachers and tutors during after school hours;
- Address underlying causes of bias and inequity in education through presentations and other public events, including a full-day conference on gender equity and education issues;
- Work with female role models and mentors that are representative of their racial and ethnic background and immigrant status;
- Maintain a web page with information for other young women; and
- Work collaboratively with other youth-focused organization doing gender-based and equity work in New York City.
- Increased understanding of gender bias and gender equity among participants;
- Proficiency in NYS Performance Standard #7 for Mathematics, Science and Technology (MST): applying the knowledge and thinking skills of MST to address real-life problems and make informed decisions;
- Disseminate information about gender bias in education and careers and obstacles to science and mathematics achievement to a broad audience;
- Share information and resources on gender equity programming and strategies for promoting girls' proficiency in mathematics and science; and
- Promote proficiency of low-income immigrant youth women who are at risk of high school non-completion in mathematics and science.


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Henry Cardwell.. Most of my covers are made of Advantec. I use them as a migratory top, and as feeder tops. I only use an outer/telescoping cover in late Winter or if Summer is very hot, just for insulation.
Different manufacturers make their equipment to different specifications. There is variation between length and depth between different companies. For instance, Some companies have the bee space at the top, others at the bottom, so depth can vary as much as 1/8 to 1/2 inch. It is good to have all your equipment the same, otherwise, you will get bridge comb, and, propolis buildup between top bars and bottom of frames. Kelly uses 9 7/8 for depth, while some companies use 9 5/8. The rabbet cut on the front and rear is also different between companies. Normally not a big problem, and it depends if the wood shrinks any after they cut the components.
There are no stupid questions if you do not know the answer. Don't ever feel embarrased to ask a question.
As for squaring the boxes. Nail or staple gun the two ends, or the two sides, (whichever way you assemble your boxes) then use a regular carpenter square to square the box by placing pressure on the side/end that is out of square, then nail or staple the other side/end. I find it easier to square after one haft is nailed rather than trying to square before nailing.
I can't think of any reason to be concerned with the equipment you currently have in use. If they are slightly off from kelly boxes, no big deal. They will still work. At worst, just a little bridge comb or propolis.
Hope this is helpful. If not, contact me at email@example.com and I will try to help you.


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A historical "document" isn't always a writing sample
Pat Shipman
The trick about studying the past is figuring out where relevant documents might be stored. I use "documents" in the broadest sense, because documents are not only written objects but also physical ones. The documents of anthropology are usually tools, ceramics, signs of buildings like walls or postholes, human remains, traces of DNA, cut or burned animal bones—tangible debris that has survived the ages. Instead of leafing through dusty archives, anthropologists dig trenches, sifting dirt for clues that humans once were there.
Looking for very early traces of human settlement in a region is difficult, whether the region is a huge continent, a small island, or in between. In most cases, the number of initial settlers was small and their remains and artifacts scarce. If there is a distinctive and common item that can be traced unquestionably to human presence—a new kind of document—then interpreting the archaeological record becomes a lot easier.
The archaeology of Remote Oceania is a perfect example of document discovery. The timeframe of human arrival in the western area (the region of Fiji, Tonga and Samoa) is reasonably clear because of the distinctive Lapita ceramics that are found in archaeological sites dating from about 950 B.C. in Fiji, Tonga and Samoa. But over time the people who had so thoughtfully littered the western islands with bits of Lapita ceramics when they first arrived made fewer and fewer ceramics. By the time people left the western region to migrate into eastern Polynesia (including New Zealand, Hawaii, the Marquesas, Rapa Nui or Easter Island and Tahiti), they had stopped making pots entirely. Thus, dating the second, eastern part of the colonization of Remote Oceania is difficult.
When humans arrived in East Polynesia is particularly significant because so many of the islands of Oceania had experienced ecological catastrophes by the time of European arrival. For example, the deforestation of Rapa Nui has become an icon of human folly and ecocide, despite recent challenges to this idea. What pattern of settlement and catastrophe prevailed in the entire region?
The archaeological and ecological record spanning human arrival in East Polynesia is most detailed and densest in New Zealand. At A.D. 1285 to 1300, Wairau Bar on South Island is the oldest well-dated archaeological site in New Zealand. On that site Maori butchered more than 8,000 moas and consumed more than 2,000 moa eggs; in upper layers, there are huge numbers of seal bones, too. There are postholes from buildings, cutmarked moa bones and broken eggshells, stone tools, and burials of 37 individuals whose graves included such items as perforated moa eggs, real and imitation whale teeth, necklace reels, shark teeth, bird bone tubes and adzes. Moa eggshells placed as grave goods in human burials were dated by the radiocarbon method. Because of Wairau Bar, A.D. 1300 can be used as a dividing line between the time periods before and after proven human arrival.
About 1000 B.C.—before human arrival—85 to 90 percent of the New Zealand landscape was forested. After A.D. 1300, pollen from tall trees declined precipitously, and by 1840 about 70 percent of the forest had been replaced by bracken ferns and grasses. Starch from the bracken root is a major part of traditional Maori diet. Bracken was not planted, but was maintained and encouraged by frequent burning to remove competing woody plants. Not surprisingly, after A.D. 1300, the frequency of charcoal-bearing layers increased dramatically, in some places by an order of magnitude. Charcoal and bracken spores documents the chronology of human settlement in this region.
"Fern root or aruhe is not the only reason Maori favored open country," argue palynologists Matt McGlone and Janet Wilmshurst of Landcare Research in New Zealand, writing with anthropologist Helen Leach of the University of Otago in the New Zealand Journal of Archaeology in 2006. Traditionally, forest impeded the Maori ability to travel for hunting, gathering or trade. In 1844, the Reverend William Colenso wrote about an overland trip on North Island in which his Maori guides were "vociferating loudly their being privileged to see a koraha maori (indigenous fern-land, open country) again" after traveling for days in dense forest.
Human presence unmistakably altered the animal community of New Zealand too. After A.D. 1300, there was a 50 percent decline in bird species—the loss of about 40 species—that once bred on the New Zealand mainland. In addition, a bat, several species of frogs and numerous lizards became extinct. Remains of all but two of the extinct birds have been recovered from at least one archaeological site, showing they were still present when humans arrived. During the early occupation period, fur seals and sea lions also underwent a marked contraction of their range.
The extinction that causes me personally the greatest heartache was of 11 species of large flightless moas. Most of these birds were about the size of ostriches, but much heavier. The one I would really love to have seen is the wonderful Dinornis or "prodigious bird" named by English paleontologist Richard Owen in 1843. Its bones indicate that the top of its back was over 6 feet high and its weight was about 550 pounds. To have missed seeing such an extraordinary creature severely saddens me.
Probably the Maori felt, or feel, the same way. In 1870 Sir George Grey recorded a Maori saying, "Ka ngaro, I te ngaro, a te moa." This phrase translates as "to be lost as the moa is lost" and refers to a tragic and irreversible loss.
But with this remarkably well-documented record, why is it so difficult to date human arrival in New Zealand? Thereby hangs the tail (forgive the pun) of the kiore or Polynesian rat, Rattus exulans. Prior to human arrival, bats were the only indigenous mammals on New Zealand or the other islands of Remote Oceania. The kiore arrived in Polynesia with humans as a notorious and highly successful stowaway, like the Norwegian rat more familiar to Europeans and Americans.
In 1994, accelerator mass spectrometry (AMS) radiocarbon dating began at the Rafter Laboratory in New Zealand, making accurate dating of small bones possible. Richard Holdaway of Canterbury University and Atholl Anderson of Australian National University got the brilliant idea of using specimens of Polynesian rats as documents of human presence. Even if the founding colonies of humans were very small and slow to reproduce, the rats that came with humans were likely to have reproduced rapidly and spread quickly. Finding and dating rat bones should be much easier than finding human bones or other human traces. Their idea was to test the reliability of rat bone dates using archaeological specimens from sites of known radiocarbon age and then to extend the method to specimens from natural sites of unknown age.
Holdaway used rat bones, excavated from New Zealand sites that had been formed by laughing owls. These birds swallow their prey whole and, after digestion, sit on favorite roosts and cough up neat little packets of bones known as owl pellets. Based on gelatin extracted from these owl pellet bones, the rats were almost 2,200 years old, as Holdaway reported in 1996 in Nature. However, this meant that rats were present on New Zealand for at least 1,000 years before the earliest archaeological record of humans. Holdaway explained the discrepancy by hypothesizing that Maori had paid an early, transient visit to New Zealand—leaving rats—but did not settle there in numbers until about A.D. 1300.
The early rat dates implied that faunal and floral extinctions in New Zealand occurred in two stages. The first stage saw perhaps a drop in species abundance, but no extinctions: that was the "rats only" phase during which the rodents bred freely and ate plants, fruits, seeds, insects, lizards, snails, eggs and nestlings of ground-breeding birds. The second stage, about 1,000 years later, saw the founding of sizeable settlements of humans who hunted, fished and trapped with enthusiasm, triggering numerous extinctions. This interpretation is known as the traditional or "long chronology" of New Zealand.
Anderson addressed the dating issue by using material from an excavation he had led between 1988 and 1992 of the huge, stratified, moa-hunting middens at a site called Shag River Mouth. The remains of at least 6,000 moas show how skillful and systematic the moa hunters were. Anderson found a pattern of deliberate butchery, with moa heads and necks discarded in one pile, pelvises in another, complete ribcages in a third. The major bone of the thigh, the femur, carried big muscles and was usually intact but the big bone of the lower leg, the tibiotarsus, was smashed, for marrow or to obtain thick bone pieces for manufacturing tools. Sometimes a heap of bones was formed of only one species of moa, suggesting that Maori may have taken down an entire flock. Moas were roasted across small depressions or ovens, many of which were preserved intact.
In addition to moa remains and ovens, there were at least 43 hearths, 36 huts, many adzes and hafted blades, fish hooks, manufacturing tools, various ornaments and two intact moa eggs, one near a human burial. At the time of excavation, Anderson took nearly 50 samples for radiocarbon dating—samples of charcoal from hearths and moa ovens, bird bone, marine shell and moa eggshell—and the dates grouped tightly around A.D. 1350 to 1400.
In the face of this hard evidence that Maori had a very well-developed and effective moa-hunting adaptation between A.D. 1300 and 1400, Anderson was troubled by the early dates Holdaway had obtained for Polynesian rats.
"It just did not make sense to me," Anderson explains, "that people could have been in New Zealand for 1,000 years before they started killing moas and seals, making shell middens, flaking stone and so on. What were they doing instead? Holdaway's default position, that people had arrived and then left almost immediately, also looked improbable to me."
"To resolve the problem, I took six samples of rat bone from the same provenances as the other 50 dating samples from Shag River Mouth. The Rafter laboratory in New Zealand (which had dated Holdaway's rat bones) dated four of them between 180 B.C. and A.D. 700, but two samples that we sent to the lab in Oxford were dated to A.D. 1000–1200. Clearly something was wrong," he says. Anderson's paper suggesting that there were technical problems with dating rat bones was published in Archaeology in Oceania in 1996, at the same time as Holdaway's Nature paper reporting the early dates on rat bones.
This led Anderson and Wilmshurst to argue for the "short" chronology, which favors a more-recent peopling of eastern Polynesia that began about A.D. 900 and reached New Zealand around A.D. 1300.
As the debate proceeded, Anderson noticed that Holdaway's dates clustered according to the time at which the Rafter Laboratory had processed them. Thirty of the first 32 dates calculated by that laboratory fell between 200 B.C. and A.D. 800. Of the next 28 dates run by the same lab, 25 were from A.D. 900 or more recent. Anderson suggested that perhaps the Rafter laboratory had failed to remove contaminating, older carbon from the rat samples in pre-treatment or the rats had incorporated older carbon from their diet into their bones.
Like Anderson, Wilmshurst had found discrepancies between Holdaway's rat dates and the evidence from the sedimentary profiles she examined in the 1990s and early 2000s. In core after core—she has studied more than 150 now—she found a major change in the flora and in the frequency of charcoal-bearing levels dating to about A.D. 1300. The signature of human arrival seemed clear and matched the archaeological evidence.
In the face of skepticism, Holdaway continued to test rat bones, seeking further refinement of the long chronology hypothesis. None of the bones in his second round of testing were as old as those in the first.
In recent years, the short chronology has been strengthened by additional new dates indicating that all of East Polynesia except New Zealand—Hawaii, the Marquesas, Easter Island, the Society Islands—was colonized about A.D. 900, much later than the rat dates in New Zealand. These findings raised a new paradox. If New Zealand was colonized at 200 B.C. and the rest of East Polynesia was not settled until A.D. 900, then the Maori colonizers of New Zealand could not have brought East Polynesian culture to New Zealand when they settled there. However, Maori culture is indisputably part of East Polynesian culture.
Coming from separate perspectives, Wilmshurst and Anderson found themselves agreeing that if the date of Wairau Bar was an accurate document of a very early colonization of New Zealand by humans, then the early rat dates could not be correct. A new approach to testing the dating was needed.
In 2001 Wilmshurst recognized a new sort of document of human presence: woody seeds that had been gnawed by rats. She had found many such seeds in her botanical samples and could easily tell rat-gnawed seeds from those broken by birds. She and dating specialist Thomas Higham of the Oxford Radiocarbon Accelerator Unit tried to resolve the debate by using rat-gnawed seeds as proxies for rats. If rats had been present for more than 1,000 years earlier than the Wairau Bar site, there ought to be plenty of older rat-gnawed seeds. But they found none older than Wairau Bar in the two North Island sites.
Urged to look for evidence on South Island, Wilmshurst added Anderson and avian paleontologist Trevor Worthy from the University of Adelaide to her team for a three-year project that used a two-prong approach. First, they re-excavated Holdaway's oldest two sites—called Predator Cave and Earthquakes #1—to collect new rat bones for dating. They also re-examined bones, now in museums, that had been originally collected by Holdaway. Second, Wilmshurst and Higham collected and dated woody seeds from a further eight sites, some on South Island.
As the team reported in a 2008 paper in the Proceedings of the National Academy of Sciences, all of the rat bones they tested were more recent than A.D. 1280. The 48 gnawed seeds they dated were all more recent than A.D. 1250. Another 48 intact or bird-broken seeds ranged in age from about 2000 B.C. to about A.D. 1800. A volcanic ash from North Island, in which they found rat-gnawed seeds, provided an independent check as it was dated to A.D. 1314. Combining all of their data, Wilmshurst and her colleagues concluded that the earliest presence of rats in New Zealand was securely dated to about A.D. 1290 to 1380, a range closely matching the dates of the older archaeological sites and confirming the short chronology. Apparently, Polynesian rats took less than 80 years to spread through out North and South Islands—about the same time span recorded for the spread of the European rat, Rattus norvegicus, after its arrival.
With the short chronology established, the massive ecological impact that has been called the "dreadful syncopation" of human arrival, faunal extinction and deforestation is also validated. Within a few centuries of their arrival, the people of eastern Polynesia devastated the animals they found in their new habitat and cut down and burned much of the forested land.
And yet, as Anderson points out, from the point of view of the invading species, this was not a disaster but a triumph.
"The first duty of colonizers is to survive. That requires rapid population growth sustained by consuming the richest resources. Relentless slaughter of large flightless birds and breeding seals, and sustained burning of the forest to open up land for edible ferns and gardening was often the result, but without such environmental change people could hardly have inhabited Remote Oceania at all."
The same might be said of rats.
You can find this online at http://www.americanscientist.org/issues/num2/the-rats-tale/3
© 2016 Sigma Xi, The Scientific Research Society