Introduction: The role of extracorporeal membrane oxygenation (ECMO) in high-risk pulmonary embolism (PE) is contentious, complicated by profound selection bias and the competing risk of early death. We sought to analyze national outcomes, with a specific focus on the clinically distinct subgroup of patients with PE-related cardiac arrest. Methods: We conducted a retrospective study of the Nationwide Inpatient Sample (2016-2022) identifying adults with high-risk PE (PE with shock or cardiac arrest). A 1-to-1 propensity score matching analysis was performed, comparing patients who received ECMO for PE-related cardiac arrest to matched controls who did not. The primary outcome was in-hospital mortality. Secondary analyses explored outcomes in non-arrest, high-risk PE patients, acknowledging the inherent limitations of comparing against a “no-ECMO, no-reperfusion” control group susceptible to survivor bias. We utilized Grammarly for editing purposes. Results: Of 488,384 high-risk PE hospitalizations, 1,260 (0.3%) received ECMO. In the primary analysis of patients with cardiac arrest, propensity score matching created a well-balanced cohort. ECMO use in this subgroup was associated with a significant reduction in in-hospital mortality (Adjusted Odds Ratio aOR 0.62; 95% CI, 0.47-0.83). In secondary analyses of non-arrest patients, comparing ECMO-based strategies to a “no-ECMO, no-reperfusion” control group yielded an association of ECMO alone with increased mortality (aOR 1.46; 95% CI, 1.19-1.78). Conclusions: In this large national analysis, the association of ECMO with survival in high-risk PE is critically dependent on the clinical context. While broad comparisons are confounded by patient selection and early mortality, ECMO use in the specific setting of PE-related cardiac arrest is strongly associated with a survival benefit. This finding supports the expanding role of E-CPR as a rescue strategy for the most critically ill PE patients.
Amalraj et al. (Sun,) studied this question.