The past few years have witnessed a resurgence of interest in the possibility that infectious processes may contribute to arterial diseases, including atherosclerosis and restenosis after arterial intervention. The recent recognition that Helicobacter pylori contributes to peptic ulcers illustrates how a disease previously believed to result primarily from excessive gastric acid production often involves a microbial pathogen. Although hypercholesterolemia clearly predisposes to development of coronary heart disease, many patients with arterial pathology have serum cholesterol levels within or below the average range. Coronary heart disease frequently affects individuals who lack other traditional risk factors as well. These findings suggest that heretofore unrecognized risk factors may also contribute to the pathogenesis of coronary heart disease.

At a recent Special Emphasis Panel convened by the National Heart, Lung, and Blood Institute, a number of experts reviewed the evidence for links between infectious processes and atherosclerosis and restenosis. This report will summarize and examine critically the evidence for involvement of infectious agents in arterial diseases based on the deliberations of this expert panel. It will also highlight some of the unanswered questions in this area that may warrant further investigation.