Association of Episodic Physical and Sexual Activity With Triggering of Acute Cardiac Events: Systematic Review and Meta-Analysis

Study Questions:

Is there an effect of episodic physical and sexual activity on acute cardiac events using data from case-crossover studies?


Two reviewers extracted descriptive and quantitative information from each study. Summary relative risks (RRs) were calculated using random-effects meta-analysis and absolute event rates based on US data for the incidence of myocardial infarction (MI) and sudden cardiac death (SCD). The Fisher p value synthesis method was used to test whether habitual physical activity levels modify the triggering effect and meta-regression to quantify the interaction between habitual levels of physical activity and the triggering effect.


The authors found 10 studies investigating episodic physical activity, three studies investigating sexual activity, and one study investigating both exposures. The outcomes of interest were MI (10 studies), acute coronary syndrome (one study), and SCD (three studies). Episodic physical and sexual activity were associated with an increase in the risk of MI (relative risk [RR], 3.45; 95% confidence interval [CI], 2.33-5.13, and RR, 2.70; 95% CI, 1.48-4.91, respectively). Episodic physical activity was associated with SCD (RR, 4.98; 95% CI, 1.47-16.91). The effect of triggers on the absolute rate of events was limited because exposure to physical and sexual activity is infrequent and their effect is transient; the absolute risk increase associated with 1 hour of additional physical or sexual activity per week was estimated at 2-3 per 10,000 person-years for MI and 1 per 10,000 person-years for SCD. Habitual activity levels significantly affected the association of episodic physical activity and MI (p < 0.001), episodic physical activity and SCD (p < 0.001), and sexual activity and MI (p = 0.04); in all cases, individuals with lower habitual activity levels had an increased RR for the triggering effect. For every additional time per week an individual was habitually exposed to physical activity, the RR for MI decreased by approximately 45%, and the RR for SCD decreased by 30%.


Acute cardiac events were significantly associated with episodic physical and sexual activity; this association was attenuated among persons with high levels of habitual physical activity.


It is well known that regular physical activity reduces an individual’s absolute risk of MI and SCD 30%, particularly for MIs and SCD occurring during strenuous activity. The authors were not able to determine whether habitual sexual activity reduces the MI and SCD rate during episodic or habitual physical activity.

Clinical Topics: Acute Coronary Syndromes

Keywords: Myocardial Infarction, Acute Coronary Syndrome, Cardiovascular Diseases, Motor Activity

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