Lowering cholesterol far beyond the levels recommended by most doctors can substantially reduce heart patients' risk of suffering or dying of a heart attack, a study has found.
The study's results, cardiologists say, will greatly change how doctors treat patients with heart disease and will provide the impetus to re-evaluate how low cholesterol levels should be, even for people without heart problems.
The study compared high doses of one of the most powerful cholesterol-lowering drugs, Lipitor, made by Pfizer Inc., with a less potent drug, Pravachol, made by Bristol-Myers Squibb, which sponsored the trial. The patients taking Lipitor were significantly less likely to have heart attacks or to require bypass surgery or angioplasty, the study found.
Both drugs are statins, a class of medications that block a cholesterol-synthesizing enzyme and are often prescribed for patients with heart problems.
"This is really a big deal," Dr. David Waters, a professor of medicine at the University of California at San Francisco, said of the findings.
"We have in our hands the power to reduce the risk of heart disease by a lot," said Waters, who had no role in the research. "It's very exciting."
National guidelines call for levels of low-density lipoprotein cholesterol, the kind that carries cholesterol to arteries, to be below 100 milligrams per deciliter in high-risk patients. But the two-year study, of 4,162 patients hospitalized for a sudden attack of chest pain from heart disease, asked whether reducing cholesterol levels far below 100 milligrams would be beneficial. It found that the answer was yes.
The study, by researchers at Harvard Medical School, will be published in the April 8 issue of the New England Journal of Medicine, which released the findings now because they were presented in New Orleans on Monday at meetings of the American College of Cardiology.
Patients in the study were randomly assigned to take Lipitor at 80 milligrams a day, the maximum dose, or Pravachol at 40 milligrams, the highest dose when the study began. The patients' cholesterol fell within the levels specified by the national guidelines. (Although Pravachol is now available in an 80-milligram dose, experts say doubling the dosage does not make much difference in its ability to reduce LDL levels.)
When the study began, the patients' cholesterol was no higher than the level specified by the national guidelines. But those who began taking Lipitor eventually had a median LDL level far below that — 62, compared with 95 among those who took Pravachol.
Within a month, the Lipitor patients started doing better than those taking Pravachol in terms of lower rates of heart attacks, bypass surgery, angioplasty and death.