Impact of lunar phase on the incidence of cardiac events

Objectives: Popular opinion holds that the phase of the moon influences human behavior, and several reports substantiate this claim; however, reports of correlation between the lunar cycle and cardiac events remain controversial. The purpose of the present study was to determine whether a relationship exists between lunar cycle and the occurrence of acute cardiac events. Methods: A retrospective review of cardiac events, including ST-elevated myocardial infarction (STEMI), non-ST elevated myocardial infarction (NSTEMI), and unstable angina, over a 5year period was performed. The dates of cardiac events were recorded and merged with the four phases of the lunar cycle (new moon, first quarter, full moon, and last quarter). Results: A total of 4751 cardiac events (578 STEMI, 1446 NSTEMI, 2727 unstable angina) occurred during the 5-year study period in 3935 unique patients. Cardiac events occurred equivalently during various phases of the lunar cycle. Conclusions: Despite popular opinion, our evidence suggests that the lunar cycle has no effect on the occurrence of acute coronary syndromes.