Impact on mortality of direct admission versus interhospital transfer in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Abstract

INTRODUCTION In a primary percutaneous coronary intervention (PCI) program, interhospital transfer of patients with ST-elevation myocardial infarction (STEMI) can increase ischemic time, compared to patients who are admitted directly to a catheterization laboratory. OBJECTIVES To assess the impact of interhospital transfer in patients with STEMI undergoing primary PCI, in terms of time to reperfusion and one-year mortality. METHODS This was an observational, retrospective, longitudinal study of patients with STEMI admitted to Hospital de Braga between June 2011 and May 2016, who were treated successfully within 12 hours of symptom onset. A total of 1222 patients were included and divided into two groups according to admission to Hospital de Braga: direct or interhospital transfer. RESULTS In this study, 37.0% (n=452) of the population were admitted directly to Hospital de Braga and 63.0% (n=770) were transferred from other hospitals. Although timings (in min) until reperfusion were longer in interhospital transfer patients (symptom onset-first medical contact (median 76.5, IQR 40.3-150 vs. 91.0, IQR 50-180, p=0.002), first medical contact-reperfusion (median 87.5, IQR 69.0-114 vs. 145, IQR 115-199, p<0.001) and symptom onset-reperfusion (median 177, IQR 125-265 vs. 265, IQR 188-400, p<0.001)), one-year mortality did not differ significantly between the groups (53 [11.7%] vs. 71 [9.2%], p=0.193). In multivariate analysis, age, symptom onset-reperfusion time and especially Killip class IV at admission (HR 11.2, 95% CI 6.35-19.8, p<0.001) were the main independent predictors of one-year mortality. CONCLUSION Interhospital transfer of patients with STEMI increased the time before PCI. No differences were detected between groups in one-year mortality. This may be related to the fact that the direct admission group had twice as many patients in Killip class IV as the interhospital transfer group.