Early mechanical reperfusion in high-risk pulmonary embolism supported by venoarterial extracorporeal membrane oxygenation: a multicenter international cohort study

OBJECTIVES: To explore how early mechanical reperfusion impacts outcomes in high-risk pulmonary embolism (PE) patients supported by venoarterial extracorporeal membrane oxygenation (VA-ECMO). METHODS: This retrospective international study included adult patients treated with VA-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 VA-ECMO (median age, 53 years), 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 = .07). Overall, ECMO duration and weaning rates were similar; however, early mechanical reperfusion improved ECMO weaning in patients without prior thrombolysis (subdistribution HR, 1.56 [95% CI, 1.03-2.36]; P = .04). Bleeding occurred in 50% of patients, with no significant difference between groups. CONCLUSIONS: In this large international cohort of patients with high-risk PE on VA-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.