Background: Cardiogenic shock is associated with high mortality. In refractory shock, it is unclear if mechanical circulatory support (MCS) devices improve survival. We conducted a systematic review and network meta-analysis to determine the impact of using various MCS devices in this population.

Methods: We searched four databases through 1 March 2023 for eligible randomised controlled trials (RCTs) and propensity-score matched studies (PSMs). We conducted frequentist network meta-analysis, investigating mortality as the primary outcome. We assessed risk of bias using the Cochrane risk of bias 2.0 tool or Newcastle Ottawa Scale, and evaluated certainty in pooled estimates using the GRADE approach. As a sensitivity analysis, we reconstructed survival data from published survival curves, and conducted one-stage unadjusted IPD meta-analysis using a stratified Cox model.

Results: We included 36 studies (48,297 patients), most reporting on patients with Society for Cardiovascular Angiography and Intervention shock stage (SCAI) C-E cardiogenic shock. Compared with no MCS, extracorporeal membrane oxygenation (ECMO) with intra-aortic balloon pump (ECMO-IABP; odds ratio [OR]: 0.60, 95%- confidence interval (CI): 0.37-0.98, moderate certainty) may be associated with lower mortality. There were no important differences in mortality using ECMO alone, microaxial ventricular assist device (mVAD) alone, IABP alone, centrifugal VAD alone, ECMO-mVAD, or mVAD-IABP (all very low certainty). One-stage IPD meta-analysis found only ECMO-IABP was associated with lower mortality (HR: 0.54, 95%-CI: 0.44-0.66).

Conclusions: In patients with cardiogenic shock, ECMO-IABP may reduce mortality. Nonetheless, results for other MCS devices are based on very low to low certainty and require further confirmation from RCTs.