Drugs called statins are already standard medicine for people recovering from heart attacks. But the study suggests newer, more potent varieties work best for these high-risk patients.
"The message for these people going home from the hospital is they should be on a high-intensity regimen," said Dr. Christopher Cannon of Boston's Brigham and Women's Hospital. "For everyone else, treating cholesterol and getting it down is very important."
The much-anticipated study helps answer one of the most discussed questions in cardiology: How low should cholesterol go? For those getting over recent heart attacks, at least, the answer appears to be very low indeed.
Those who did best in this study saw their levels of LDL, the bad cholesterol, plunge in half to an average of just 62. The goal in current federal guidelines is to get LDL below 100.
The study was to be presented Monday in New Orleans at the annual scientific meeting of the American College of Cardiology. It also will be published in Thursday's issue of the New England Journal of Medicine.
The latest work reinforces the conclusion of another head-to-head comparison of statin drugs released last November. In that study, doctors found the more intensive treatment resulted in less artery clogging. The new report is considered even more persuasive because it looks for differences in the risk of death and other clearly measurable misfortunes of heart patients.
Both studies compared 40 milligrams daily of Pravachol to 80 milligrams of Lipitor, the highest approved doses of both drugs when the research started. Pravachol is an older statin made by Bristol-Myers Squibb, while the newer and more potent Lipitor is made by Pfizer. Last fall's study was financed by Pfizer, and this one was paid for by Bristol-Myers Squibb. Lipitor came out on top in both comparisons.
In Cannon's study, 4,162 patients with new heart attacks or severe chest pain were randomly assigned to the two drugs. After two years of follow up, 26 percent getting the weaker Pravachol had died or experienced a variety of other ill events, including new heart attacks, bypass surgery, rehospitalization for chest pain or strokes. The same happened in 22 percent on Lipitor.
LDL levels of those taking Pravachol fell to 95, which is considered successful treatment under the government guidelines drawn up several years ago.
Dr. Thomas Pearson, head of preventive medicine at of the University of Rochester, helped write those guidelines. "The goal of less than 100 was an approximation using some very early data," he said. "It was the best guess at that moment. It may need some improvement. Now we are getting the science, and that's really exciting."
In a journal editorial, Dr. Eric Topol of the Cleveland Clinic called the latest finding "a major surprise," in part because the superiority of the stronger statin became obvious within a month of the start of treatment.
Topol said 36 million Americans should be on statins, although only a third that many actually are. Nevertheless, statins are the biggest selling category of prescription drugs at $12.5 billion in the United States each year.
Other studies in the works should help settle whether people with less serious heart disease benefit from the more aggressive cholesterol lowering possible with the newer statins. The more powerful drugs carry a slightly higher risk of side effects and are more expensive. Topol noted that the dose of Pravachol used in the study costs about $900 a year, while Lipitor costs $1,400.
Dr. Andrew Bodnar, head of medical affairs at Bristol-Myers Squibb, said until more studies are done, "doctors should reserve judgment about the general coronary disease population." He noted abnormal liver enzymes were more common in patients on Lipitor in the latest study and said Pravachol "has an unsurpassed safety record."
By Daniel Q. Haney