Early mechanical reperfusion in high-risk pulmonary embolism supported by V-A ECMO: a multicenter international cohort study

Objectives: To explore how early mechanical reperfusion impacts outcomes in high-risk pulmonary embolism (PE) patients supported by veno-arterial extracorporeal membrane oxygenation (V-A ECMO). Methods: This retrospective international study included adult patients treated with V-A ECMO for high-risk PE at 39 ECMO centers (2014-2024). Early mechanical reperfusion was defined as catheter-directed therapy or surgical embolectomy within 48 hours of ECMO initiation. Patients dying within 12 hours or receiving delayed reperfusion were excluded. The primary outcome was 90-day mortality, assessed using propensity-matched groups. Measurements and main results: Among 492 patients on V-A ECMO (median age 53), 69% had cardiac arrest, and 28% received early mechanical reperfusion. After propensity matching, 137 patients were compared in each group. Ninety-day mortality was 32% with early mechanical reperfusion on ECMO versus 39% with ECMO stand-alone (HR 0.68; 95% CI, 0.45-1.03; p = 0.07). Overall, ECMO duration and weaning rates were similar; however, early mechanical reperfusion improved ECMO weaning in patients without prior thrombolysis (sHR 1.56; 95% CI, 1.03-2.36; p = 0.04). Bleeding occurred in 50% of patients, with no significant difference between groups. Conclusion: In this large international cohort of patients with high-risk PE on V-A ECMO, early mechanical reperfusion therapy was not associated with a reduction in 90-day mortality or ECMO duration. These findings may support a stepwise, individualized approach favoring initial ECMO stand-alone support, although a certain clinical benefit from early mechanical reperfusion in selected patients cannot be excluded.