Researchers have been working to solve this problem with scanners that provide pictures of the arterial wall itself, but it’s a tricky task. Normal cardiac artery walls are about a millimeter thick. Coronary arteries move with every beat of the heart, 70 times a minute. It’s tough to get a clear image of something so small in constant motion.

Difficult, but not impossible. As I walk through the basement of the Cleveland Clinic, I pass a room containing a large, blue, plastic doughnut as tall as I am, with a woman’s legs sticking out of the middle. The doughnut is a computed tomography (CT) scanner, a kind of three-dimensional x-ray machine that’s also used for imaging tumors. The scanner, aided by medications that reduce a patient’s heart rate and an injectable dye that highlights the arteries, can produce startlingly clear pictures.

Scrolling through images on his computer monitor, Mario Garcia, the clinic’s director of cardiac imaging, retrieves one that looks like a black-and-white landscape photographed from a plane, with a single, large river running through it. As Garcia zooms in on the river, a series of white lumps appears on the bank—hard plaques bright with calcium. But there is also a tiny black smudge. “That’s the type we believe causes a heart attack,” he says with satisfaction, pointing to the smudge of soft plaque. “It’s a rare opportunity to see that.”

As compelling as the CT scan is, it’s still an imperfect tool for predicting heart disease. It’s expensive, for one, and the dose of radiation from the x-rays makes it ill suited for use in healthy-patient annual exams. And although it sees arterial plaques, even soft plaques inside arterial walls, it can’t reveal whether those plaques are likely to crack and cause a heart attack.

Until there are tests, genetic or otherwise, that give a clearer measure of risk, everyone would be advised to exercise, watch their diet, and take statins for elevated cholesterol—the same advice doctors gave when the clogged-pipes model of heart disease reigned unchallenged.

At the Cleveland Clinic, cardiologist Stephen Nissen has conducted several studies on statins such as Lipitor, which reduce the amount of LDL (“bad” low-density lipoprotein) cholesterol made by the liver. Nissen is an advocate of lowering cholesterol by any means necessary. Does he take a statin? “You bet!” he says. “I have no intention of dying of the disease I treat.” His LDL level is a paltry 51. Of eight cardiologists I spoke with, all but one were taking the medication. (Some studies now seem to show that lowering even normal cholesterol levels has a protective effect.) HDL (“good” high-density lipoprotein) cholesterol is another story. Nissen calls it the “arterial-wall garbage barge” because of its ability to remove cholesterol from clogged arteries. Not all HDL can do this; some is dysfunctional. But tests have shown that raising the HDL level in genetically engineered lab mice can shrink their arterial plaques.