Optimal reperfusion strategy in acute high-risk pulmonary embolism requiring extracorporeal membrane oxygenation support: a systematic review and meta-analysis

Background and objectives: The optimal pulmonary revascularization strategy in high-risk pulmonary embolism (PE) requiring implantation of extra corporeal membrane oxygenation (ECMO) remains controversial. We conducted a systematic review and meta-analysis of evidence comparing mechanical embolectomy and other strategies, including systemic, catheter-directed thrombolysis, or ECMO as stand-alone therapy, with regard to mortality and bleeding outcomes. Methods and results: We identified 835 studies, 17 of which were included, comprising 327 PE patients. Overall, 32.4% were treated with mechanical pulmonary reperfusion, (of whom 85.9% had surgical embolectomy), while 67.61% received other strategies. The mortality rate was 26.4% in the mechanical reperfusion group, and 42.8% in the other strategy group. The pooled OR for mortality with mechanical reperfusion was 0.43 (95%CI, 0.23-0.997); p = 0.009; I² = 35.2%) versus other reperfusion strategies; and 0.36 (95% CI, 0.18-0.73; p = 0.009; I² = 32.9%) for surgical embolectomy vs thrombolysis. The rate of bleeding in patients under ECMO was 24.5% in the mechanical reperfusion group and 19.6% in the other reperfusion group (OR, 1.26; 95% CI, 0.54-2.92; I², 7.7%). The meta-regression model did not identify any relationship between the covariates “more than one pulmonary reperfusion therapy”, “ECMO implantation before pulmonary reperfusion therapy”, clinical presentation of PE, or cancer-associated PE, and the associated outcomes. Conclusions: The results of the present meta-analysis and meta-regression suggest that mechanical reperfusion, notably by surgical embolectomy, may yield favorable results regardless of the timing of ECMO implantation in the reperfusion timeline, independent of thrombolysis administration or cardiac arrest presentation.