How Aspirin Protects Against Heart Attacks.

Why does simple aspirin use protect some people from heart attacks? Researchers at Ohio State University, Columbus, have traced the mechanism back to a specific genetic factor present on the surface of clotting cells called platelets. The discovery could help to determine which people at risk for heart attacks and coronary disease might benefit from daily doses of aspirin and who might need other non-aspirin drugs to gain the same effect.

Earlier studies have shown that about 25-50% of the population can reduce their risk of a heart attack if they take daily doses of aspirin. Until now, though, researchers didn't understand why this beneficial effect occurred or why aspirin's benefit was limited to less than half of patients. The new research suggests that aspirin specifically may target patients who display an altered gene, called the [P1.sup.A2] polymorphism, which impacts upon the protective action of aspirin.

Generally speaking, genes are changed by one of two mechanisms--mutations and polymorphisms. Mutations tend to occur in a small portion of the population and are the genetic changes most often closely linked to diseases because they alter the function of the protein product, the blueprint of which has been disrupted by the mutation. Polymorphisms, on the other hand, are gene changes that do not grossly alter the function of the gene product, but, instead, provide alternative templates for the making of certain proteins. These polymorphisms are much more common in the population and can represent improvements in the genetic makeup of species over time.

Glen Cooke, a...