Science & Health
9:00 am
Tue November 19, 2013

Critics Warn Latest Cholesterol Guidelines Invite Overtreatment

Originally published on Tue November 19, 2013 3:15 pm

The launch of new treatment guidelines isn't a good time for confusion and controversy.

But that's precisely what's happening to a set of sweeping new guidelines aimed at slashing the U.S. rate of heart attacks and strokes — the first reboot of such advice in seven years.

If such guidelines are going to work, Dr. Steven Nissen points out, they have to convince.

"We need the public's support here," the Cleveland Clinic cardiologist says. "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."

The guidelines, promulgated by the American Heart Association and American College of Cardiology at the behest of the National Institutes of Health, are aimed at preventing a first heart attack or stroke in millions of Americans.

"Because this affects so many people, we have to get it right," Nissen says.

But when Dr. Paul Ridker saw the cholesterol guidelines last Tuesday evening, he was troubled.

Ridker, who directs the Center for Cardiovascular Disease Prevention at Brigham and Women's Hospital in Boston, had caught an advance peek at the document many months earlier. Back then he advised the team writing the guidelines that their proposed calculator to predict people's risk of heart attack and stroke might overestimate that risk because it relied on old data. His caution apparently fell on deaf ears, though, because when it came out, the formula hadn't changed.

So Ridker and Harvard colleague Nancy Cook tested the new risk calculator using more current data from three big studies.

"We found that it overestimated risk by a substantial amount," Ridker tells Shots. "On average, it was between 75 and 150 percent — so a rough doubling. And that's a substantial overestimation."

He thinks the reason is that the cardiovascular risk of U.S. adults has changed quite a lot over the past two decades and more. "Not only are rates of smoking lower, but people tend to exercise more and they're on better diets," Ridker says. "If you use a prediction model that uses older data, that might or might not tell you what's relevant now."

Ridker 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 — he will probably get cholesterol-lowering drugs in any case. But it's a different story if somebody's real risk is low and the calculator overestimates that risk.

"If a person's true risk is 3 or 4 percent and you wouldn't treat, but [the risk calculator] increases it to 8 or 9 percent and you would, it raises the possibility that we might not be getting the right drugs to the right patient at the right time," Ridker says.

On Monday, the guideline writers stoutly defended their work at a press conference in Dallas, where the Heart Association is holding its big annual scientific sessions.

"The truth is, the risk equations work exactly as we asked them to do," says Dr. Donald Lloyd-Jones of Northwestern University, who led a panel that developed the new risk calculator. "The question is: Are they the right populations? We selected populations that were representative of the U.S. in the mid-1990s."

He points out that estimating people's risk of heart attack or stroke 10 years into the future requires following them to see what happens to them, and they've got to be followed for at least 10 years. "I'd love to snap my fingers, take a population existing today and know what their outcomes are going to be in 10 years," Lloyd-Jones says. "But you just can't do that."

He argues that Ridker and Cook's analysis ­underestimates risk, because it used research subjects who were much healthier than the average American. The analysis mined data from the Nurses Health Study, the Women's Health Initiative and the Physicians Health Study.

For his part, Ridker stresses that he supports 95 percent of the new guidelines. But he'd like to see their implementation delayed until scientists can figure out how to deal with the problem of risk projection.

"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," Ridker says, as you continue to try to identify other factors you may not have taken into account.

At the moment, that doesn't appear likely. American Heart Association President Mariell Jessup said at Monday's media briefing that the organization will go ahead with the risk calculator and guidelines as is.

"We are implementing this approach to the prevention of cardiovascular disease," Jessup says. "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."

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

Transcript

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. Transcript provided by NPR, Copyright NPR.