Prognostic implications of complications during VA-ECMO for cardiogenic shock

PURPOSE: Veno-arterial extracorporeal oxygenation (VA-ECMO) provides comprehensive cardiopulmonary support in patients with cardiogenic shock (CS), but may result in complications. While complications rates are known, their impact on risk of death remains largely unknown. METHODS: Using the Extracorporeal Life Support Organization (ELSO) Registry to identify adults with a diagnosis of CS treated with VA-ECMO (2017-2024), we analyzed the association between timing and type of complication and in-hospital mortality using three methodologies: 1) Cox proportional hazards analysis, treating complications as time-dependent covariates; 2) Multi-State Model (MSM) analysis, treating complications as transient states and estimating the differential mortality rate from each of these states; and 3) landmark Kaplan Meier survival analysis, estimating conditional survival curves, given survival to 3 weeks, based on count and timing of complications. RESULTS: Among 22,547 patients (31.7% female), 12,094 (54%) died during index hospitalization. More non-survivors experienced complications than survivors (74% vs 54%), with all sub-types occurring more frequently. Neurologic complications increased the hazard of mortality by 3.6 (95% C.I 3.4 - 3.8). MSM analysis indicated that the absolute 30-day risk of mortality was greater if a patient had a complication, increasing from 48.6% (0 complications) to 93.1% with a neurologic complication. Landmark survival analysis demonstrated that patients without complications within the first 3 weeks had the highest conditional survival. CONCLUSION: Complications on VA-ECMO have a significant and cumulative effect on in-hospital mortality, with a higher number associated with increased risk of death. Neurologic and pulmonary complications were associated with the greatest mortality risk.