RESUMEN
BACKGROUND: Timely percutaneous coronary intervention (PCI) improves prognosis in ST-elevation myocardial infarction (STEMI). However, recent reports indicate that patients with STEMI who present during non-regular working hours (off-hours) have a worse prognosis. The aim of this study was to compare outcome between patients with STEMI who underwent primary PCI during off-hours and regular hours. METHODS: We retrieved data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) for all patients who underwent primary PCI in Region Västra Götaland due to STEMI between January 2004 and May 2013. We modeled unadjusted and adjusted Cox proportional-hazards regression and logistic regression models for the outcomes death, cardiogenic shock, stent thrombosis and in-stent restenosis. A propensity score-adjusted Cox proportional-hazards model, which adjusted for traditional cardiovascular risk factors was predefined as the primary statistical model. Death at any time during the study period was pre-specified as primary end-point. RESULTS: During the study period 4.611 (65%) patients underwent primary PCI due to STEMI during off-hours and 2,525 (35%) during regular hours. The risk of dying was similar among the groups for the primary endpoint death at any time during the study period (HR 1.00, 95% CI 0.89-1.12, P = 0.991) and for secondary end-point death within 30 days (HR 1.03; 95% CI 0.85-1.25, P = 0.735). The risks of developing cardiogenic shock, stent thrombosis, or in-stent restenosis were similar between the groups. CONCLUSIONS: In our region, short- and long-term prognosis for patients with STEMI who undergo primary PCI is similar for patients presenting during off-hours and regular hours.