Office Hours” versus “After Office Hours” presentation in ST-segment elevation myocardial infarction and its impact on door-to-balloon time and clinical outcome : findings from a single center registry

Aim: We evaluated the clinical characteristics, door-to-balloon (D2B) time and clinical outcomes of STEMI patients who presented during “office hours” and “after office hours in our single center registry. Method: From January 2009 to December 2014, 1661 STEMI patients (86% male, mean age 58+12 years) underwent PPCI at our center. We divided the patients into two groups according to time of presentation to emergency department. “After office hour PCI” was defined by intervention performed during weekdays from 6PM-8AM, weekends, and public holidays. Data were collected retrospectively on baseline clinical characteristics, symptom onset to reperfusion time, D2B time, angiographic findings, therapeutic modality and hospital course. Result: The majority (62%) of STEMI patients in our registry presented “after office hours”. For the “after office hours” group, there was a higher proportion of male patients (88% vs 83%, p=0.003). They also have a higher prevalence of hypertension, prior MI and prior PCI compared to “office hours” group. Patients in the “after office hours” group had a longer D2B time (mean 55+42 mins; median 56 mins) vs the “office hours” group (mean 47+41; median 45 mins) (p=0.0002). The proportion of patients achieving D2B time