Infections and their role in atherosclerotic vascular disease.

BACKGROUND: Complications of atherosclerosis are the leading cause of mortality in developed countries, and infections may play a role in the pathogenesis. Numerous studies have addressed this issue in the past decade. TYPES OF STUDIES REVIEWED: The author examined peer-reviewed studies and reviews on the role of microbes or infections in atherosclerosis, cardiovascular disease and cerebrovascular disease. He included selected articles on epidemiology, pathology, in vitro experiments, animal models and clinical studies.
RESULTS: Cross-sectional and retrospective studies have shown an association between Chlamydia pneumoniae antibodies and cardiovascular disease, but prospective studies have not been as convincing. Studies on the association between cardiovascular disease and periodontal disease or loss of teeth have produced conflicting results. Cytomegalovirus infection is associated mainly with accelerated arteriosclerosis after cardiac transplantation. Infectious agents can induce biological mechanisms important for atherogenesis. Mice and rabbit studies have indicated that C. pneumoniae is capable of initiating or accelerating the progression of atherosclerosis. Limited studies on cytomegalovirus also suggest the ability to induce early changes of atherosclerosis in a rodent model. Preliminary clinical trials of treatment for C. pneumoniae infection suggest a possible short-term benefit, but larger randomized trials for longer periods are in progress. CONCLUSION AND CLINICAL IMPLICATIONS: Infectious agents may play an important role in atherogenesis, but currently the jury is not in. Further management of cardiovascular disease could change radically if this concept were proven.