Clinical efficacy of direct or indirect left ventricular unloading during venoarterial extracorporeal membrane oxygenation for primary cardiogenic shock

Objective: Left ventricular (LV) distention is a feared complication in patients receiving venoarterial (VA) extracorporeal membrane oxygenation (ECMO). LV unloading can be achieved indirectly with intra-aortic balloon pump (IABP) or directly with an Impella device (Abiomed, Danvers, Mass). We sought to assess the clinical and hemodynamic effects of IABP and Impella devices on patients supported with VA ECMO.

Methods: We conducted a retrospective review of VA ECMO patients at our institution from January 2015 to June 2020. Patients were categorized as either ECMO alone or ECMO with LV unloading. LV unloading was characterized as either ECMO with IABP or ECMO with Impella. We recorded baseline characteristics, survival, complications, and hemodynamic changes associated with device initiation.

Results: During the study, 143 patients received ECMO alone whereas 140 received ECMO with LV unloading (68 ECMO with IABP, 72 ECMO with Impella). ECMO with Impella patients had a higher incidence of bleeding events compared with ECMO alone or ECMO with IABP (52.8% vs 37.1% vs 17.7%; P < .0001). Compared with ECMO alone, ECMO with IABP patients had better survival at 180 days (log rank P = .005) whereas survival in ECMO with Impella patients was not different (log rank P = .66). In a multivariable Cox hazard analysis, age (hazard ratio [HR], 1.02; 95% confidence interval [CI], 1.00-1.03; P = .015), male sex (HR, 0.54; 95% CI, 0.38-0.80; P = .002), baseline lactate (HR, 1.06; 95% CI, 1.02-1.11; P = .004), baseline creatinine (HR, 1.06; 95% CI, 1.00-1.11; P = .032), need for extracorporeal membrane oxygenation-cardiopulmonary resuscitation (HR, 2.09; 95% CI, 1.40-3.39; P = .001), and presence of pre-ECMO IABP (HR, 0.45; 95% CI, 0.25-0.83; P = .010) were associated with reduced mortality. There was no significant difference in hemodynamic changes in the ECMO with IABP versus ECMO with Impella cohorts.

Conclusions: Concomitant support with IABP might help reduce morbidity and improve 180-day survival in patients receiving VA ECMO for cardiogenic shock.