Impella to unload the left ventricle in patients undergoing venoarterial extracorporeal membrane oxygenation for cardiogenic shock: A systematic review and meta-analysis

Background and Aim Impella is frequently used to unload the left ventricle in patients with cardiogenic shock on venoarterial extracorporeal membrane oxygenation (VA-ECMO). There is limited data regarding the use of this strategy. This study aims to evaluate the safety and efficacy of the said strategy. Methods A systematic search for studies comparing Impella plus VA-ECMO (ECVAD) vs VA-ECMO alone was performed using Pubmed, Cochrane Library, and Scopus. Studies meeting inclusion criteria were then used to perform a meta-analysis. Results Three studies involving 448 patients were included in the final analysis. In total, 117 (26%) patients were female, mean age was 57 years. VA-ECMO was placed in 355 out of 448 (79%) patients, while ECVAD was placed in 93 out of 448 (21%). Death occurred in 49 out of 93 (52.6%) patients on ECVAD and 226 out of 355 (63.6%) on ECMO, relative risk (RR): 0.76, confidence interval (CI), 95% (0.62-0.94) P = .01. Hemolysis was present in 46 (49.4%) patients in the ECVAD vs 67 (18%) in the ECMO group, RR: 2.64, CI, 95% (1.97-3.55) P < .01. Bleeding was present in 42 (45.2.%) patients in the ECVAD group and 135 (38%) in the ECMO group, RR: 1.25, CI, 95% (0.95-1.63) P = .11. CVVHD was used on 31 (33.3%) patients in the ECVAD group while 89 (25%) in the ECMO group, RR 1.35, CI, 95% (0.95-1.91) P = .10. Conclusion This study suggests that the use of Impella as an unloading strategy in patients with VA-ECMO decreased mortality, increased rate of hemolysis, neutral bleeding risk, and similar rates of acute kidney injury requiring CVVHD.