IMPELLA COMPARED TO VENOARTERIAL EXTRACORPOREAL MEMBRANE OXYGENATION IN CARDIOGENIC SHOCK: A SYSTEMATIC REVIEW AND META-ANALYSIS OF PROPENSITY SCORE-MATCHED STUDIES.

Background: Veno-arterial extracorporeal membrane oxygenation (VA ECMO) and Impella, a transluminal microaxial ventricular assist device, are well-established in the management of cardiogenic shock. No randomized controlled trials (RCTs) directly compare Impella versus VA ECMO to inform their safety and efficacy in cardiogenic shock. Purpose: This study aims to conduct a systematic review and meta-analysis of propensity score-matched/adjusted studies to compare the clinical outcomes of Impella versus VA ECMO in cardiogenic shock patients. Methods: A systematic review was undertaken to identify comparative studies of Impella and VA ECMO in cardiogenic shock, which in the absence of RCTs, was limited to observational trials with propensity-matched or adjusted outcomes to account for important confounding factors between populations. In-hospital/30-day survival and bleeding events requiring transfusion were meta-analyzed using the random effects method. Results: Five propensity score-matched/adjusted studies comparing short-term survival following treatment with Impella versus VA ECMO were included. A statistically significant difference in in-hospital/30-day mortality was detected between patients treated with Impella (39.6%) versus VA ECMO (53.8%) (odds ratio [95% confidence interval]: 0.57 [0.44, 0.74]; P < 0.0001). Impella was associated with significantly fewer bleeding events requiring transfusion compared with VA ECMO (19.9% vs. 28.8%, respectively) (OR [95% confidence interval]: 0.61 [0.46, 0.80]; P = 0.0004). Conclusion: In the absence of RCTs, this meta-analysis of propensity matched/adjusted observational trials represents the highest level of evidence available to date. Impella was associated with improved short-term survival and decreased bleeding events compared to VA ECMO in patients with cardiogenic shock.