Opening blocked coronary arteries: New questions about the old answer

The facts are so familiar (and so depressing) that they hardly need repetition. Heart disease is the leading cause of death in the United States. Despite all the marvelous advances in diagnosis and treatment, it's held that dubious distinction every year since the 1918 influenza pandemic. In most cases, the culprit is coronary artery disease, which is responsible for the heart attack that strikes an American every 26 seconds the year round. In all, about 650,000 Americans will die from coronary artery disease this year.

While these facts have not changed substantially, the scientific understanding of heart disease has evolved. The disease is caused by cholesterol-laden blockages (plaques) in the arteries that carry oxygen-rich blood to the heart muscle. It seemed obvious that big plaques, which produce the most narrowing, would be the most hazardous. Research has challenged that view, but aggressive treatment is often aimed at clearing the most tightly blocked arteries. Remarkable technical advances have made these treatments routine, but studies show that not all patients benefit equally.