Infections, atherosclerosis, and coronary heart disease

There is growing evidence that the immune response is involved in atherosclerosis. Studies done over the past several years have shown an association between markers of inflammation and coronary atherosclerosis with an exacerbation of the inflammatory process during acute myocardial ischemia. Overall, these data have greatly renewed interest in the infectious theory of atherosclerosis and coronary heart disease. Search of bibliographic databases (from January 1991 through December 1999) and manual scanning of both peer-reviewed publications and other documents were used to identify pertinent literature. Infections and coronary heart disease were indexed as key words. A large number of studies have reported an association of human coronary heart disease and certain persistent bacterial and viral infections. The association between Chlamydia pneumoniae and coronary heart disease appears quite significant although the sequence of infection and disease is uncertain. The association between Helicobacter pylori and coronary heart disease may be accounted for by residual confounding from classic risk factors. Preliminary findings indicate that this association could be due to a higher prevalence of more virulent Helicobacter strains. Infection with Cytomegalovirus appears to be associated with a greater risk of restenosis after angioplasty rather than primary atherosclerosis. Early trials of appropriate antibiotic therapy in subjects with recent acute myocardial infarction have been encouraging. A causal relationship between infections and coronary heart disease is still elusive. Improved studies involving prospective collection of data are required to demonstrate such an association with potential implications for public health worldwide.