Time of admission, quality of PCI care, and outcome of patients with ST-elevation myocardial infarction

Our study aimed to analyse the hospital mortality of patients admitted in- and off-regular working hours with ST-elevation myocardial infarction (STEMI) within the special logistical setting of the urban area of the city of Berlin. There is a debate whether patients with acute myocardial infarction admitted to hospital outside regular working hours experience higher mortality rates than those admitted within regular working hours. This study analyses data from the Berlin Myocardial Infarction Registry and comprises 2,131 patients with STEMI and treated with percutaneous coronary intervention (PCI) in 2004-2007. Data of patients admitted during in- and off-regular working hours were compared. There was significant difference in door-to-balloon time (median in-hours: 79 min; median off-hours: 90 min, p < 0.001) and in hospital mortality (in-hours: 4.3%; off-hours: 6.8%, p = 0.020) between STEMI patients admitted in- and off-hours for treatment with PCI. After adjustment, admission off-hours remained an independent predictor for in-hospital death for patients (OR = 2.50; 95% CI 1.38-4.56). In patients with primary care from physician-escorted Emergency Medical Services (EMS), door-to-balloon time was reduced by 10 min for in-hours as well as off-hours patients. The difference in hospital mortality between off-hour and in-hour admission was reduced to a non-significant OR = 1.61 (95% CI 0.79-3.27). In conclusion, patients admitted off-hours experienced longer door-to-balloon times and higher hospital mortality than did those admitted in-hours. The differences observed between patients admitted in-hours and off-hours were reduced through physician-escorted EMS reflecting the influence of optimized STEMI care.