Prognostic implications of level-of-care at tertiary heart centers compared with other hospitals after resuscitation from out-of-hospital cardiac arrest

Abstract

Background - Studies have found higher survival rates after out-of-hospital cardiac arrest and admission to tertiary heart centers. The aim was to examine the level-of-care at tertiary centers compared with nontertiary hospitals and the association with outcome after out-of-hospital cardiac arrest. Methods and Results - Consecutive out-of-hospital cardiac arrest patients (n=1078) without ST-segment-elevation myocardial infarction admitted to tertiary centers (54%) and nontertiary hospitals (46%) were included (2002-2011). Patient charts were reviewed focusing on level-of-care and comorbidity. Survival to discharge differed significantly with 45% versus 24% of patients discharged alive (P<0.001), and after adjustment for prognostic factors admissions to tertiary centers were still associated with lower 30-day mortality (hazard ratio, 0.78 [0.64-0.96; P=0.02]), independent of comorbidity. The adjusted odds of predefined markers of level-of-care were higher in tertiary centers: admission to intensive care unit (odds ratio [OR], 1.8 [95% confidence interval, 1.2-2.5]), temporary pacemaker (OR, 6.4 [2.2-19]), vasoactive agents (OR, 1.5 [1.1-2.1]), acute (<24 hours) and late coronary angiography (OR, 10 [5.3-22] and 3.8 [2.5-5.7]), neurophysiological examination (OR, 1.8 [1.3-2.6]), and brain computed tomography (OR, 1.9 [1.4-2.6]), whereas no difference in therapeutic hypothermia was noted. Patients at tertiary centers were more often consulted by a cardiologist (OR, 8.6 [5.0-15]), had an echocardiography (OR, 2.8 [2.1-3.7]), and survivors more often had implantable cardioverter defibrillator's implanted (OR, 2.1 [1.2-3.6]). Conclusions - Admissions to tertiary centers were associated with significantly higher survival after out-of-hospital cardiac arrest in patients without ST-segment-elevation myocardial infarction in the Copenhagen area even after adjustment for prognostic factors including comorbidity. Level-of-care seems higher in tertiary centers both in the early phase, during the intensive care unit admission, and in the workup before discharge. The varying level-of-care may contribute to the survival difference; however, differences in comorbidity do not seem to matter significantly.