Impact of complications on survival outcomes in different temporary mechanical circulatory support techniques: A large retrospective cohort study of cardiac surgical and nonsurgical patients.

Background: Temporary mechanical circulatory support (tMCS) has become a standard treatment in cardiogenic shock but is associated with high complication rates. This study analyzes common complications associated with modern tMCS devices and their impact on mortality depending on the tMCS approach.

Methods: We conducted a retrospective single-center analysis of patients with all-cause cardiogenic shock treated with veno-arterial extracorporeal life support, microaxial flow pump, and a combination of both (ECMELLA). The primary outcome was the impact of cumulative complications on mortality, evaluated separately for nonsurgical (non-PCCS) and cardiac surgical (PCCS) patients. Secondary outcomes included the impact of complications on mortality stratified by tMCS type and rates of bleeding, the need for renal replacement therapy (RRT), hemolysis, neurological complications, bloodstream infections, and ischemic limb complications.

Results: We included 493 patients, totaling 4,881 days on tMCS support. Non-PCCS patients with 1 complication had a hazard ratio (HR) of 1.92 (95% confidence interval [CI]: 1.22, 3.00, p = 0.004) for mortality and 3.73 (95% CI: 2.48, 5.60, p < 0.001) for 2 or more complications compared to those without complications. In PCCS patients, 1 complication was associated with an HR of 2.22 (95% CI: 1.29, 3.81, p = 0.004) and 3.44 (95% CI: 2.04, 5.78, p < 0.001) for 2 or more complications. The most common complications in both non-PCCS and PCCS patients were bleeding (33% and 60%), need for RRT (31% and 43%), and severe hemolysis (26% and 35%).

Conclusion: Complications among tMCS-treated patients are common and clearly associated with an elevated mortality risk.