Meta-analysis of the morning excess of acute myocardial infarction and sudden cardiac death

Although acute cardiovascular events occur throughout the day, it has been shown that acute myocardial infarction (AMI), sudden cardiac death (SCD), silent ischemia, and stroke have a circadian pattern of occurrence with a peak in the morning hours.(1-6) However, the proportion of morning events that are in excess of those expected and, more importantly, the proportion of all events that are attributable to the morning excess in the population at large remains unknown. We performed a meta-analysis of published reports related to circadian variation in AMI and SCD to define the proportion of events that are attributable to the morning excess.