Neurological outcomes and reperfusion strategies in out-of-hospital cardiac arrest patients due to pulmonary embolism who underwent venoarterial extracorporeal membrane oxygenation: A post-hoc analysis of a multicenter retrospective cohort study.

INTRODUCTION:This study aimed to evaluate the effect of different reperfusion strategies on neurological outcomes in patients with pulmonary embolism who received venoarterial extracorporeal membrane oxygenation (VA-ECMO) for out-of-hospital cardiac arrest (OHCA). METHODS:This was a post-hoc analysis of a multicenter retrospective cohort study conducted in 36 institutions in Japan over six years. We included patients who underwent VA-ECMO and were diagnosed with pulmonary embolism caused by OHCA. Neurological outcomes were evaluated on the basis of the cerebral performance category at hospital discharge. We also assessed the association between reperfusion strategies and successful separation from ECMO. RESULTS:Among the 78 included patients, approximately half were successfully weaned from ECMO. Hospital mortality and favorable neurological outcomes at hospital discharge were 60.3% and 17.9%, respectively. Thirty-one patients (39.7%) underwent reperfusion strategies after ECMO, including 13 who received systemic thrombolytic therapy and 18 who underwent mechanical reperfusion strategy. After adjusting for prespecified covariates using the competing risk model, reperfusion strategies increased ECMO separation rate (systemic thrombolytic therapy: subdistribution hazard ratio [sHR] 2.24, 95% confidence interval [CI] 1.21-4.17, P = 0.011; mechanical reperfusion strategy: sHR 1.70, 95% CI 0.86-3.41, P = 0.129) compared with anticoagulation therapy alone, whereas higher cardiac Sequential Organ Failure Assessment score decreased ECMO separation rate (sHR 0.81, 95% CI 0.67-0.97, P = 0.020). CONCLUSIONS:Favorable neurological outcomes were observed in less than 20% of patients with OHCA due to pulmonary embolism undergoing ECMO. Reperfusion strategies may be associated with shorter ECMO durations in these patients. CLINICAL TRIAL REGISTRATION:https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000041577 (unique identifier: UMIN000036490).