A periprocedural myocardial infarction, defined as the advent of new Q-waves or a creatine kinase-MB elevation >83 normal has been previously validated as predictive of subsequent mortality. We examined the effects of using this clinically relevant definition of periprocedural myocardial infarction instead of the original protocol definition on outcomes in the recent PROTECT II [A Prospective, Multi-center, Randomized Controlled Trial of the IMPELLA RECOVER LP 2.5 System Versus Intra Aortic Balloon Pump (IABP) in Patients Undergoing Non Emergent High Risk PCI] trial. In this trial, patients who were undergoing high-risk percutaneous coronary intervention (PCI) were randomized to either an intraaortic balloon pump (IABP, n[211) or a left ventricular assist device (Impella, n[216). All eligible patients per study protocol were included in the analysis. Patient outcomes were compared up to 90 days, the longest available follow-up, on the composite end points of major adverse events (MAE) and major adverse cardiac and cerebral events (MACCE [ death, stroke, myocardial infarction, and repeat revascularization). At 90 days, the rates of both composite end points were lower in the Impella group compared with the IABP group (MAE, 37% vs 49%, p [ 0.014 respectively; MACCE, 22% vs 31%, p [ 0.034 respectively). There were no differences in death or large myocardial infarction between the 2 arms. By multivariable analysis, treatment with Impella as opposed to IABP was an independent predictor for freedom from MAE (odds ratio[0.75 [95% confidence interval 0.61 to 0.92], p[0.007) andMACCE (odds ratio[0.76 [95% confidence interval 0.61 to 0.96], p[0.020) at 90 days postprocedure. In conclusion, hemodynamic support with Impella compared with IABP during high-risk PCI in the PROTECT-II trial resulted in improved event-free survival at 3-month follow-up; this finding was further supported by multivariate analyses.
Trial registration: ClinicalTrials.gov NCT00562016.