Bill Clinton's Big Test

"I really think it probably saved my life," Bill Clinton told Larry King, speaking not about the bypass operation he had last week but about the test — an angiogram — that first showed that the arteries feeding blood to his heart were dangerously blocked. "If people have a family history there, and high cholesterol and high blood pressure," Clinton said, "they ought to consider the angiogram."

Good advice? Yes and no. An angiogram is the gold standard of heart tests, and in Clinton's case it picked up a problem that all his previous stress tests and electrocardiograms had missed. But an angiogram is not something to be taken lightly. It involves injecting a dye directly into the blood vessels of your heart through a catheter that has been threaded into your chest from an artery in your groin. By taking X-ray images of the dye, doctors can get a pretty clear picture of where blood is flowing freely and where there are constrictions.

But angiograms are not risk free. In about one case out of 1,000, according to Dr. Richard Stein, associate chairman of medicine at Beth Israel Medical Center in New York City, there are complications — including, in rare cases, strokes. For patients who have never had any symptoms (such as the chest pains and shortness of breath that Clinton experienced) and whose stress tests are normal, the risks outweigh the benefits, says Stein.

That's why there has been so much attention given lately to a noninvasive test called electron beam computed tomography (EBCT). It uses a burst of X rays to show how much calcium has been deposited in the coronary arteries — a good measure of how much plaque has accumulated there. In a study published in the Journal of the American College of Cardiology, more than half of 1,119 patients who passed their stress tests had high calcium scores in subsequent EBCTs, suggesting significant hardening of the arteries.

An EBCT is not the end of the story. If you get a high calcium count, you will still need an angiogram so your doctor can tell precisely where your arteries are blocked. But EBCTs are spotting a lot of hidden heart disease. Although some insurance companies are reluctant to pay for this new test, its use is growing rapidly, and it may eventually become part of the standard heart work-up.

Sanjay Gupta is a neurosurgeon and CNN medical correspondent