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 randomised 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 vs. 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-analysed using the random effects method. RESULTS: Five propensity score matched/adjusted studies comparing short-term survival following treatment with Impella vs. VA ECMO were included. A statistically significant difference in in-hospital/30-day mortality was detected between patients treated with Impella (39.6%) vs. VA ECMO (53.8%) (odds ratio [OR] 95% confidence interval [95% CI]: 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 = 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.