Conflicting results exist on the outcome of off hours PCI in ST elevation myocardial infarction (STEMI). However, there were only a few studies that have focused on the clinical characteristics and outcomes of off hours PCI in STEMI. So, we studied th...
Conflicting results exist on the outcome of off hours PCI in ST elevation myocardial infarction (STEMI). However, there were only a few studies that have focused on the clinical characteristics and outcomes of off hours PCI in STEMI. So, we studied the clinical characteristics and hospital mortality in STEMI patients treated with primary PCI during regular hours (weekdays 9:00 AM to 6:00 PM) versus off hours Weekdays 6:01 PM to 8:59 AM, weekends, and holidays) in Korea Acute Myocardial Infarction Registry. We analyzed in hospital and one year mortality among 5,665 consecutive ST segment elevation myocardial infarction patients treated with primary PCI between November 2005 to January 2008. Total 2,848 (50.2%) patients were treated during off hours. Baseline finding were similar, although regular hours patients were older. Median symptom to balloon time (304 min, IQR 175 to 750 vs. 270 min, IQR 145 to 551, p=0.001) were longer for regular hours primary PCI. Median door to balloon time (71min, IQR: 48 to 132 vs. 59 min, IQR 39 to 110 min, p=0.001) were longer for off hours pPCI. Also, Cardiac enzyme such as Max CK-MB (212.1±299.3 vs 194.7±303.4, p=0.031) and max TnI (72.6±239.5 vs. 58.9±94.4, p=0.013) were increased in off hours pPCI. However, unadjusted in hospital (6.0% off hours vs. 6.0% regular hours, p=0.946) and one year cardiac mortality (11.3% off hours vs. 11.7% regular hours, p=0.661) were comparable. In multivariate analysis, off hours primary PCI did not predict an adverse outcome. In conclusion, when primary PCI was performed within an appropriate reperfusion strategy, the clinical effectiveness of either off hours or regular hours pPCI is comparable.