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 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."