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Controversy, confusion over new cardiovascular-risk guidelines

Cardiologist Dr. Paul Ridker and biostatistician Nancy Cook, both of Harvard, say the risk-assessment calculator in the new guidelines is seriously flawed.

Statins are among the safest prescription drugs available, but they do have adverse side effects in some patients.
REUTERS/Jeff Zelevansky

The controversy over the new cardiovascular-disease treatment guidelines released last week by the American Heart Association (AHA) and the American College of Cardiology (ACC) heated up considerably over the weekend.

As Gina Kolata reported Monday in the New York Times, heart-disease experts from those two organizations held an emergency session Saturday night during the AHA’s annual meeting. They had been notified on Friday by two Harvard Medical School professors, cardiologist Dr. Paul Ridker and biostatistician Nancy Cook, that the risk-assessment calculator in the new guidelines was seriously flawed.

Ridker and Cook had tested the calculator, which takes into account such factors as age, gender, race, blood pressure and cholesterol levels, on 100,000 health participants in three large long-running studies (the Women’s Health Study, the Women’s Health Initiative, and the Physician’s Health Study) and found it overstates the risk of heart disease by 75 to 150 percent.

“A man whose risk was 4 percent, for example, might show up as having an 8 percent risk,” Kolata writes. “With a 4 percent risk, he would not warrant treatment — the guidelines [say that] treatment is advised for those with at least a 7.5 percent risk and that treatment can be considered for those whose risk is 5 percent.”

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Ridker and Cook detailed their criticisms of the new guidelines in a commentary published online today in the journal Lancet.

“[I]t is possible that as many as 40 to 50 percent of the 333 million middle-aged Americans targeted by the new ACC/AHA guidelines for statin therapy do not actually have risk thresholds exceeding the 7.5 percent level suggested for treatment,” the two Harvard professors wrote in a draft version of the commentary obtained by MinnPost on Monday.

“It’s stunning,” former ACC president Dr. Steve Nissen told Kolata. “We need a pause to further evaluate this approach before it is implemented on a widespread basis.”

No plans to delay

However, in a hastily called press conference on Monday, AHA and ACC officials declared that there would be no delay in implementing the new guidelines.

The officials discounted Ridker and Cook’s findings, claiming that the two professors had tested the new guidelines’ calculator on populations that were healthier than the general American public.

In an interview with the Boston Globe, Cook said such a concern is valid. But she also noted, writes Globe reporter Deborah Kotz, that “one of the studies that she and Ridker analyzed was broadly representative of the general population and not any healthier — and yet the risk calculator didn’t work well for this group either.”

The officials at the press conference did acknowledge that the calculator will undoubtedly require some modification in the coming years as more is learned about cardiovascular risk factors. In the meantime, though, they are advising doctors to start using it with their patients.

“We think we’ve done our due diligence,” said AHA president Dr. Mariell Jessup. “We have faith and trust in the people who developed the guidelines.”

Conflicts of interest

But, as two other critics of the new guidelines noted in an editorial published last Thursday in the New York Times, financial conflicts of interest by the AHA, the ACC and some of the authors of the guidelines undermine that trust.

“The process by which these latest guidelines were developed gives rise to further skepticism,” wrote Dr. Rita Redberg, a cardiologist at the University of California, San Francisco Medical Center and the editor of JAMA Internal Medicine, and Dr. John Abramson, a lecturer at Harvard Medical School. “The group that wrote the recommendations was not sufficiently free of conflicts of interest; several of the experts on the panel have recent or current financial ties to drug makers. In addition, both the American Heart Association and the American College of Cardiology, while nonprofit entities, are heavily supported by drug companies.”

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And Ridker has his own conflict of interest.

“Ridker receives royalties as co-holder of patents on a diagnostic test for C Reactive Protein (CRP), a marker for inflammation that could be tied to increased risk for heart disease,” reported Randsell Pierson and Bill Berkrot of Reuters on Monday.

One of the authors of the new guidelines, Dr. David Goff, dean of the Colorado School of Public Health, told the Reuters reporters that Ridker had suggested in his review of the proposed guidelines last year that CRP testing be included in the risk assessment calculations.

That suggestion was rejected.

Weighing the risks and benefits

What should patients do in the wake of all this controversy, confusion and conflicts of interest? The editors of the New York Times published on Tuesday what seems to be some wise advice:

Statins are among the safest prescription drugs available, but they do have adverse side effects in some patients, including muscle pain and muscle damage; an increased risk of diabetes, especially in women; memory loss and confusion; cataracts; and, rarely, kidney or liver damage.

For patients who clearly need treatment, the benefits of statins will almost always outweigh the risks. But healthier patients will need to make a judgment, in consultation with their doctors, on whether these risks are worth taking without evidence they will benefit. They should probably wait until the heart organizations reassess their risk calculator, the possible flaws in it, and how best to fix them.