Sex and myocardial infarction: an epidemiologic perspective

The relation between sexual activity and acute myocardial infarction (MI) risk is one of great interest to people at risk for MI and their physicians. However, understanding this relation requires an appreciation of the complex interplay among relative, attributable, and absolute risk. Because there is an underlying risk of MI in the population, the risk of MI after sexual activity must be compared with this underlying baseline risk. The estimated relative risk of MI after sexual activity is approximately 2.5 during the 2-hour period after sex, indicating a 2.5-fold increase in risk over baseline. However, because the baseline risk during any 2-hour period is very low, the absolute increase in risk (the risk from sexual activity minus the baseline risk), is extremely small (e.g., 0.01% over a year for low-risk individuals engaging in weekly sexual activity and 0.1% for higher-risk individuals). In addition, the attributable risk (the percentage of MIs due to sexual activity) is <1%. Thus, any individual's risk of MI during sexual activity is low. Nonetheless, factors that may decrease the risk of MI after sexual activity are important to explore, and include regular exercise and perhaps medication use, such as aspirin and beta blockers. Although there may be a long-term cardiovascular and mortality benefit to regular sexual activity, current data supporting this theory are limited. This article describes the relation between sexual activity and acute MI with respect to the complex interplay among relative, attributable, and absolute risk. Limitations of studies examining the potential long-term benefits of regular sexual activity are also discussed.