Drugs Cut Rate of 2nd Heart Attack, Study Says
The new generation of cholesterol-lowering drugs can dramatically reduce the risk of a second heart attack even among individuals who have normal cholesterol levels, a finding that could extend use of the drugs to as many as 5 million additional people, researchers said Tuesday.
The new family of drugs, called statins, has previously been shown to provide dramatic reductions in the risk of heart disease among people with high cholesterol, regardless of whether they have had a heart attack.
The new results, presented at the annual meeting of the American College of Cardiology in Orlando, Fla., indicate that virtually everyone who has had a heart attack--irrespective of their cholesterol levels--can benefit from the drugs.
The study “is likely to change the practice of medicine because it documents, for the first time, a benefit of treatment with pravastatin in post-heart attack patients without an elevated cholesterol level,” said Dr. Eugene Braunwald of Harvard’s Brigham and Women’s Hospital. “And these are the patients most frequently encountered in clinical practice.”
The results “have enormous implications for the situation in the United States,” where 70% of the 7 million heart attack survivors have normal cholesterol levels, said Dr. Terje R. Pederson of Aker Hospital in Oslo, who headed a large study of the related drug simvastatin. “This is the final proof of the cholesterol hypothesis--that you should lower your cholesterol if you are at high risk of heart disease.”
Braunwald and his colleagues studied 4,159 people who had suffered a heart attack, but whose average cholesterol was 209 milligrams per deciliter of blood, about the U.S. average.
Overall, use of the drug pravastatin reduced the incidence of second heart attacks 24%. For women, the results were more impressive--a 45% reduction in risk.
The results were so impressive that physicians might even consider using the drug in people with normal cholesterol levels who have not had a heart attack, especially if they have other risk factors for heart disease, such as smoking or diabetes, said Dr. Syd Smith of the University of North Carolina in Chapel Hill, acting president of the American Heart Assn.
More than 12 million people in the United States have heart disease, according to the National Institutes of Health. The new research suggests that the vast majority could benefit from one of the four statins now sold in this country, Braunwald said. Heart disease is the leading cause of death in the United States, killing more than 923,000 people each year.
The five-year “Cholesterol and Recurrent Events” trial was conducted at 80 centers in the United States and Canada. The participants were 24 to 75 years of age and had suffered a heart attack in the previous two years. Half received a placebo and half pravastatin, which carries the trade name Pravachol.
The statins, which have come into use during the last decade, block synthesis of cholesterol in the liver.
In addition to the reduction in heart attacks and death, the drug also reduced other coronary incidents. Those who received pravastatin were 26% less likely to need coronary bypass surgery and 22% less likely to need angioplasty. Benefits were apparent in all subgroups studied, including smokers and people with hypertension and diabetes.
“We were very excited about the benefits to women,” said Dr. Frank M. Sacks of Brigham and Women’s, one of the principal investigators. He noted that for every 1,000 women treated, the drug prevented 248 cardiovascular events, such as heart attack. “It shows that there is no question that women can be benefited.”
One concern, however, was that there were 12 cases of breast cancer among women who received pravastatin, compared to only one among those who received the placebo. Sacks said the team will reexamine the women who suffered breast cancer to try to explain this finding before the results are published.
But he suspects that the higher incidence of breast cancer is a statistical mistake. “We’re not discounting it, but we feel that since it comes . . . with absolutely no evidence from animal work or other human studies, it’s quite possible that it is an anomaly based on small numbers and multiple statistical testing,” he said.
