Only half of the people at moderate or high risk for heart disease are getting the recommended cholesterol-lowering drugs that can reduce their risk of a heart attack or death, according to a new study.

Researchers say although the use of the most popular class of cholesterol-lowering drugs known as statins has exploded in recent years, the findings show that doctors need to be more aggressive about prescribing the drugs to those who could benefit from them most.

Based on national surveys, the study showed that statins were prescribed about half the time during doctor's office visits for people at high risk and 44 percent of the time for people at moderate risk for heart disease.

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People at high risk for heart disease were those with high cholesterol levels and evidence of heart disease, stroke, or diabetes. Moderate-risk patients had high cholesterol and two or more heart disease risk factors, such as obesity, high blood pressure, and cigarette smoking.

In addition, the study showed that less than half of those at risk for heart disease received counseling from their doctors on how they might lower their risk through diet, exercise, or quitting smoking.

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Trends in Treating Heart Disease

Statins were introduced 17 years ago and reduce the level of cholesterol produced by the liver while improving the liver's ability to remove the so-called "bad" LDL cholesterol from the blood.

Although statins are now the most commonly prescribed class of drugs, researchers say this is the first study to examine statin use in a large national sample based on their level of heart disease risk.

Using information from two national databases that tracked outpatient visits to hospitals and doctors' offices from 1992 and 2002, researchers looked at what type of medications were prescribed or continued during those visits. Then they matched that information to the patient's level of heart disease risk.

The results showed statin use rose from 14 percent in 1992 to 50 percent in 2002 among those at high risk for heart disease and from 9 percent to 44 percent among those at moderate risk.

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"It's disconcerting that the magnitude of the increase is much smaller than expected," says researcher Jun Ma, MD, PhD, research associate at the Stanford Prevention Research Center, in a news release. "The rate of use falls significantly short of the latest recommendations."

Researchers also found certain groups were less likely to be prescribed a statin despite their heart disease risk, including: younger patients, women, African-Americans, and people cared for by physicians who were not cardiologists.

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Overuse vs. Underuse

Researchers say statins aren't appropriate for everyone and the risks of these or any other drugs have to be weighed against the benefits. In this case, people at high risk for heart disease have the most gain from statins to lower their cholesterol and reduce their risk.

Although recent headlines have been dominated by drugs that may have been overused by people who had little to gain from them, researchers say this is different.

"You have to look at drug therapy on a case-by-case basis. We have many situations where drugs are misused or overused," says Ma. "In this particular case, although we did observe some inappropriate use of statins in low-risk patients, the predominant problem appears to be underuse in higher-risk patients."

The study, which appears in the May 31 issue of the Public Library of Science, was funded by an unrestricted grant from Merck Co., which manufactures statins, and the Agency for Healthcare Research and Quality. Merck is a WebMD sponsor.

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By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCES: Ma, J. PLoS Medicine, May 2005; vol 2. News release, PLoS Medicin