Background: Mass media deliver pertinacious rumours that lunar phases influence the progress and long-term results in several medical procedures. Peer reviewed studies support this, e.g. in myocardial infarction, others do not.
Methods: We looked retrospectively at the dates of cardiac arrests (CA; n=368) of cardiac origin and of acute myocardial infarctions (AMI) with consecutive thrombolytic therapy or acute PTCA (n=872) and at the lunar phases at the corresponding dates. Medical data had been collected prospectively on the patient's admission. The lunar phases were defined as full moon+/-1 day, new moon+/-1 day and the days in between as waning and waxing moon. The incidence of these cardiac events at each phase was calculated as days with a case divided by the total number of days of the specific moon phase in the observation period (1992-1998). Wilcoxon Rank Test was used for statistical analysis.
Results: AMI and CA occurred on equal percentages of days within each lunar phase: AMI on 35% of all days with new moon, on 38% of full moon days, on 39% waning, and on 41% of the waxing moon days; CA on 19, 17, 16 and 16% of all days of the respective lunar phase. This difference was not significant.
Conclusion: Lunar phases do not appear to correlate with acute coronary events leading to myocardial infarction or sudden cardiac death.