New strategy of higher doses of statins works to reduce LDL cholesterol and risks of strokes and heart attacks. Although some patients developed liver problems that forced them to stop taking the medication, the researchers said, the benefits of the treatment outweighed the risks. But the researchers said more study was needed to establish its safety.
The study was financed by Pfizer, which makes atorvastatin under the brand name Lipitor, one of six statin drugs that have proved effective in reducing low density lipoprotein, or L.D.L., the bad cholesterol.
A previous study found that giving high-dose statins to lower L.D.L. below 100 milligrams per deciliter had helped people who had recently suffered a heart attack.
The new study involved people who had clogged heart arteries that occasionally caused chest pain but were in no immediate danger of a heart attack. Up to 13 million Americans are in that category.
About 10,000 people in 14 countries took Lipitor in either large or small doses. Those taking 10 milligrams a day brought their L.D.L. levels to an average of 101 milligrams per deciliter. But those taking 80 milligrams attained an average of 77.
After nearly five years, 10.9 percent of those on the low dose had died or suffered a stroke, heart attack or other major problem. For those on the high dose, the figure was 8.7 percent. That means patients on high doses had a 22 percent relative reduction in risk.
But the reduced risk of heart attack and stroke from the higher dose did not translate into a lower risk of death over all, because many more people died from other factors on the higher dose. Over all, 284 patients taking 80 milligrams died, compared with 282 patients taking 10 milligrams.
About 1.2 percent of the patients developed signs of liver inflammation on the high dose, compared with 0.2 percent in the other group. That was in line with other studies that tested high doses of statins.
Usually the inflammation clears up when people are taken off the drug, but patients need to be aggressively tested and monitored, said Dr. Sidney C. Smith, an American Heart Association spokesman who is a cardiologist at the University of North Carolina.
In an editorial in the medical journal, Dr. Bertram Pitt of the University of Michigan School of Medicine said it was not known whether aggressively lowering L.D.L. was the best strategy for cutting the risk of heart attacks or, if so, whether high-dose statins were the best way to do that. The tactic needs to be compared with other approaches, like raising high density lipoprotein, or H.D.L., the so-called good cholesterol, or by adding other drugs to conventional doses of statins.
"We need further reassurance as to the safety of this approach before we can advocate a major shift in our current goals for L.D.L. cholesterol in patients with stable" coronary heart disease, he wrote. Dr. Smith said two studies now under way should provide more information within a year.
The findings were presented at a meeting of the American College of Cardiology. They were also published online by The New England Journal of Medicine and will be in its April 7 issue.