This is about half the risk for those with known coronary disease. But the risk of a cardiovascular event rose by 50 percent in patients with cerebrovascular disease or peripheral artery disease alone, compared with patients who only had coronary disease.

And the risk of a cardiovascular event more than doubled when patients with only known coronary disease were compared to those with the combination of coronary, cerebrovascular, and peripheral artery disease (3.1 percent compared with 7.4 percent). These findings are particularly troubling because most of the study's patients were already being treated with statins, antihypertensive medications, and/or aspirin.

The study demonstrates the widespread distribution of atherosclerosis in the body and highlights the cumulative increase in risk when the disease is found at multiple sites. One of the study authors stated that doctors "should now view patients not as walking coronaries or walking peripheral arteries, but really patients who have global atherothrombosis (atherosclerosis affecting arteries throughout the body)."

The take-home message for patients is that they should make sure their doctors look beyond the heart and the traditional risk factors to determine cardiovascular risk. Examinations should also evaluate the status of the carotid arteries in the neck and the peripheral arteries in the legs.