Impact of Center Volume on Outcomes in Myocardial Infarction Complicated by Cardiogenic Shock: A CULPRIT-SHOCK Substudy.

Background Little is known about the impact of center volume on outcomes in acute myocardial infarction complicated by cardiogenic shock. The aim of this study was to investigate the association between center volume, treatment strategies, and subsequent outcome in patients with acute myocardial infarction complicated by cardiogenic shock. Methods and Results In this subanalysis of the randomized CULPRIT-SHOCK (Culprit Lesion Only PCI Versus Multivessel PCI in Cardiogenic Shock) trial, study sites were categorized based on the annual volume of acute myocardial infarction complicated by cardiogenic shock into low-/intermediate-/high-volume centers (<50; 50-100; and >100 cases/y). Subjects from the study/compulsory registry with available volume data were included. Baseline/procedural characteristics, overall treatment, and 1-year all-cause mortality were compared across categories. n=1032 patients were included in this study (537 treated at low-volume, 240 at intermediate-volume, and 255 at high-volume centers). Baseline risk profile of patients across the volume categories was similar, although high-volume centers included a larger number of older patients. Low-/intermediate-volume centers had more resuscitated patients (57.5%/58.8% versus 42.2%; P<0.01), and more patients on mechanical ventilation in comparison to high-volume centers. There were no differences in reperfusion success despite considerable differences in adjunctive pharmacological/device therapies. There was no difference in 1-year all-cause mortality across volume categories (51.1% versus 56.5% versus 54.4%; P=0.34). Conclusions In this study of patients with acute myocardial infarction complicated by cardiogenic shock, considerable differences in adjunctive medical and mechanical support therapies were observed. However, we could not detect an impact of center volume on reperfusion success or mortality.