Clinical outcomes of the intra-aortic balloon pump for resuscitated patients with acute myocardial infarction complicated by cardiac arrest

Background: The aim of this study was to investigate the clinical effects of intra-aortic balloon pump (IABP) in patients who received cardiopulmonary resuscitation (CPR) before procedure. Methods and results: Between November 2005 and April 2014, 49,542 patients were enrolled in a prospective cohort study for acute myocardial infarction (AMI) in Korea (KAMIR). CPR was performed in 1700 patients with cardiac arrest. Patients were excluded from the study if they had not undergone a coronary angiogram, if extracorporeal membrane oxygenation or thrombolysis was performed, and if mechanical complications presented. The primary end point was 1-month all-cause mortality. A total of 883 patients in the IABP group and 476 in the control group were included. During the 1-month follow-up, all-cause death occurred in 749 patients (55.1%). The IABP group was predominantly male and had a higher prevalence of ST-segment elevation MI and a higher risk of coronary lesions including left main disease and three-vessel disease. Glycoprotein IIb/IIIa inhibitor was administered less in the non-IABP group. In the total population, the IABP group had worse outcomes in terms of mortality rates after multivariate analysis [hazard ratio (HR) 1.22, 95% confidence interval (CI) 1.02-1.47, p = 0.034] without increasing the incidence of recurrent MI, stroke, and major bleeding. After propensity matching with a pair of 452 patients, no significant differences were observed in baseline characteristics or clinical outcomes (HR 1.21, 95% CI 0.93-1.57, p = 0.158). Conclusion: The use of IABP did not show clinical benefits in patients with AMI complicated by severe cardiogenic shock after propensity matching analysis.