STEMI mortality decreased drastically during the last decades, and out-of-hospital sudden cardiac arrest (SCA) has become its main cause of death. The risk of SCA according to the month of STEMI occurrence has not been assessed. Hypothesis: The risk of SCA varies according to the month of STEMI occurrence.
Methods:
Data were taken from a prospective pre-hospital study (e-MUST study) on STEMI patients managed by emergency medical services in Paris and its suburbs between January 2006 and December 2010. In this area, emergency calls are routed to the closest dispatch center and regulated by physicians who send an ambulance with a physician on board in case of suspected acute myocardial infarction. Pre-hospital EKGs are obtained for all patients and those presenting STEMI are included in the study. We assessed and compared the rate of SCA according to the month of STEMI occurrence.
Results:
Among the 8112 STEMI patients enrolled (mean age (SD) 61.6years (14.3), 78% males), 452 patients (5.6%) developed out-of-hospital SCA. We observed significant temporal changes in the rate of SCA per STEMI over the year. The peak rate of SCA per STEMI occurred in June (8.7%), while the lowest rate was in December (3.45%) (Figure). Conclusions: The risk of SCA varies significantly according to the month of STEMI occurrence, with STEMI occurring in June being at the highest risk for SCA while those occurring in December have the lowest risk. A better understanding of the pathophysiological mechanisms of this difference is needed to eventually reduce the risk of out-of-hospital SCA after STEMI diagnosis.
Autonomic control of ventricular tachycardia: Direct effects of beta-adrenergic blockade in 24 hour old canine myocardial infarction