Prospective study of herpes simplex virus, cytomegalovirus, and the risk of future myocardial infarction and stroke

Background-It has been hypothesized that infection with either herpes simpl ex virus (HSV) or cytomegalovirus (CMV) is associated with atherogenesis. H owever, prospective data relating evidence of prior exposure to these agent s with risks of future myocardial infarction (MI) and stroke are sparse. Methods and Results-In a prospective, nested case-control study of apparent ly healthy men, the baseline prevalence of antibodies directed against HSV or CMV was similar among 643 men who subsequently developed a first MI or t hromboembolic stroke and among 643 age- and smoking-matched men who remaine d free of reported vascular disease over a 12-year follow-up period. Specif ically, the relative risks for future MI and stroke were 0.94 (95% CI, 0.7 to 1.2) for HSV seropositivity and 0.72 (95% CI, 0.6 to 0.9) for CMV seropo sitivity, after adjustment for other cardiovascular risk factors. These fin dings were not materially altered in comparisons of early versus late event s or in analyses stratified by smoking status. There was no evidence of ass ociation between HSV or CMV antibodies and plasma concentration of C-reacti ve protein, a marker of inflammation that predicts Vascular risk in this co hort. Conclusions-Among apparently healthy middle-aged men, IgG antibodies direct ed against HSV or CMV do not appear to be a marker for increased atherothro mbotic risk. The observed possible inverse relationship of CMV with MI and stroke was unexpected and may well be due to chance, because the direction of association is not compatible with the a priori hypothesis based on prop osed biological mechanisms or previous cross-sectional and retrospective da ta.