Differential Prognostic Implications of Vasoactive Inotropic Score for Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock According to Use of Mechanical Circulatory Support*

Abstract

OBJECTIVES: To identify whether the prognostic implications of Vasoactive Inotropic Score according to use of mechanical circulatory support differ in the treatment of acute myocardial infarction complicated by cardiogenic shock. DESIGN: A multicenter retrospective and prospective observational cohort study. SETTING/PATIENT: The REtrospective and prospective observational Study to investigate Clinical oUtcomes and Efficacy registry includes 1,247 patients with cardiogenic shock from 12 centers in Korea. A total of 836 patients with acute myocardial infarction complicated by cardiogenic shock were finally selected, and the study population was stratified by quartiles of Vasoactive Inotropic Score (< 10, 10-30, 30-90, and > 90) for the present study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Primary endpoint was in-hospital mortality and secondary endpoint was follow-up mortality. Among the study population, 326 patients (39.0%) received medical treatment alone, 218 (26.1%) received intra-aortic balloon pump, and 292 (34.9%) received extracorporeal membrane oxygenation. In-hospital mortality occurred in 305 patients (36.5%) and was significantly higher in patients with higher Vasoactive Inotropic Score (15.6%, 20.8%, 40.2%, and 67.3%, for < 10, 10-30, 30-90, and > 90; p < 0.001). Vasoactive Inotropic Score showed better ability to predict in-hospital mortality in acute myocardial infarction patients with cardiogenic shock who received medical treatment alone (area under the curve: 0.797; 95% CI, 0.728-0.865) than in those who received intra-aortic balloon pump (area under the curve, 0.704; 95% CI, 0.625-0.783) or extracorporeal membrane oxygenation (area under the curve, 0.644; 95% CI, 0.580-0.709). The best cutoff value of Vasoactive Inotropic Score for the prediction of in-hospital mortality also differed according to the use of mechanical circulatory support (16.5, 40.1, and 84.0 for medical treatment alone, intra-aortic balloon pump, and extracorporeal membrane oxygenation, respectively). There was a significant interaction between Vasoactive Inotropic Score as a continuous value and the use of mechanical circulatory support including intra-aortic balloon pump (interaction-p = 0.006) and extracorporeal membrane oxygenation (interaction-p < 0.001) for all-cause mortality during follow-up. CONCLUSIONS: High Vasoactive Inotropic Score was associated with significantly higher in-hospital and follow-up mortality in patients with acute myocardial infarction complicated by cardiogenic shock. The predictive value of Vasoactive Inotropic Score for mortality was significantly higher in acute myocardial infarction patients with cardiogenic shock treated by medical treatment alone than in those treated by mechanical circulatory support such as intra-aortic balloon pump or extracorporeal membrane oxygenation.