ROBERT SIEGEL, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel.
MELISSA BLOCK, HOST:
I'm Melissa Block.
And we begin this hour with confusion. Last week, we reported on new guidelines for treating cholesterol. Well, those guidelines were sharply challenged today at a meeting of heart specialists in Dallas. At the center of the controversy is a risk calculator released last week by the American Heart Association and the American College of Cardiology. Critics charge the calculator grossly overestimates some people's risk of a heart attack or stroke. If true, that could lead to millions of people getting cholesterol-lowering drugs who don't need them. NPR's Richard Knox sorts out the controversy.
RICHARD KNOX, BYLINE: The launch of big, new medical treatment guidelines is not a good time for confusion. That's because if guidelines are going to work, they have to persuade, says Dr. Steven Nissen of the Cleveland Clinic.
DR. STEVEN NISSEN: We need the public's support here. You know, doctors can write prescriptions for drugs but patients have to want to take them. And what I fear is at risk here is confusion that prevents people who would benefit from getting the drugs and may lead to the wrong people getting these drugs.
KNOX: The new guidelines are aimed at preventing a first heart attack or stroke in millions of Americans. Because this affects so many people, Nissen says, the experts have got to get it right. But when Dr. Paul Ridker saw the new cholesterol guidelines last Tuesday, he was troubled. He'd had an advanced peek many months before. Back then, he advised the guideline writers that a new calculator to predict people's risk of heart attack and stroke might overestimate that risk because it relied on old data. But when it came out, the formula hadn't changed, so Ricker and Harvard statistician Nancy Cook tested the new risk calculator using more current data from three big studies.
DR. PAUL RIDKER: We found that it overestimated risk by a substantial amount. On average, it was between 75 and 150 percent, so a rough doubling. And that's a substantial overestimation.
KNOX: Ridker's an expert on cardiovascular risk at Brigham and Women's Hospital in Boston. He says it's not such a big deal if a formula overestimates the risk of somebody whose chances of a heart attack and stroke are high because they'll probably get cholesterol-lowering drugs anyway. But it's a different story if somebody's risk is low and the calculator is overestimating that risk.
RIDKER: If a person's true risk is 3 or 4 percent and you wouldn't treat but now it increases to 8 or 9 percent and you would, it raises the possibility that we might not be getting the rights drugs to the right patient at the right time.
KNOX: Which is the whole point of the guidelines. Today, the guideline writers strongly defended their work at a press conference in Dallas, where the heart association is holding its big yearly meeting.
DR. DONALD LLOYD-JONES: The truth is the risk equations work exactly as we asked them to do. There's nothing wrong with these equations.
KNOX: That's Dr. Donald Lloyd-Jones, who led a panel that developed the new risk calculator. He argues that Ridker and Cook's analysis actually underestimates the risk because it used people who are much healthier than the average American. Lloyd-Jones says his panel based the new formula on people more broadly representative of the U.S. population, including African-Americans and those at risk for stroke. Ridker says he supports 95 percent of the new guidelines but he'd like to see their implementation delayed until scientists can figure out the problem.
RIDKER: I think when you see a signal like that, when the data don't quite make sense, the most responsible thing to do is stop and sit tight and try to figure out what are the issues that are out there.
KNOX: At the moment, that doesn't appear likely. Heart association president Mariell Jessup said at today's press conference that it's going ahead with the calculator and guidelines as is.
DR. MARIELL JESSUP: We are implementing this approach to the prevention of cardiovascular disease. We think we've done our due diligence. We have faith and trust in these investigators. And ultimately, as with all guidelines, the implementation is at the level of the patient and the practitioner.
KNOX: So the heart association and the College of Cardiology will have to convince all those patients and doctors that their guidelines are trustworthy. Richard Knox, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.