A novel trigger for acute coronary syndromes: the effect of lunar cycles on the incidence and in-hospital prognosis of acute coronary syndromes--a 3-year retrospective study.

Circadian variations in the incidence of hypertension and coronary events are well known with early morning surges. Effect of lunar cycles on various medical illnesses like seizures and psychiatric disturbances are documented. However, the effect of lunar cycles on coronary events has been sparsely documented. The authors studied the incidence of acute coronary events and admission patterns in the departments of emergency medicine and cardiology. Inclusion criteria included unstable angina, non-ST elevation myocardial infarction (MI) and ST elevation MI. Exclusion criteria included chest pain syndromes which were subsequently deemed non-cardiac by invasive or non-invasive investigations. Data from 1999 to 2001 were analysed. Admissions on full moon days were compared with those on new moon days. There were 30 full moon days and 30 new moon days and 223 admissions on full moon days and 266 on new moon days. This difference was statistically significant [p = .005]. Sixty-seven per cent were males and the rest were females. Subgroup analysis of mortality, postinfarction angina, effect on diabetics and hypertensives were done which showed an increased trend in new moon days. It is concluded that there is increased incidence of acute coronary events associated with new moon days.