D'Andria Ursoleo, Jacopo

Pulmonary embolism (PE) is a leading cause of cardiovascular morbidity and mortality. Systemic thrombolysis is recommended for high-risk PE, but risk of major bleeding limits its use despite its efficacy. While mechanical thrombectomy (MT) has emerged as an alternative reperfusion strategy, real-world safety data remains limited. The objective of this single-center retrospective observational cohort study was to characterize the safety profile and procedural complications of MT. Methods Adult patients with intermediate-risk and high-risk PE who underwent MT at a quaternary academic medical center between January 1, 2017, and December 31, 2024, were included. Demographic, clinical, laboratory, imaging, procedural, outcome, and mortality data were collected. Major adverse events and bleeding were defined according to established criteria. Results From a total of 103 screened patients, 65 were included. Of these, 22 (34%) were classified as high-risk and 43 (66%) as intermediate-risk. Baseline demographics were similar between groups. High-risk patients demonstrated greater clinical disease severity, with higher mean Pulmonary Embolism Severity Index (PESI) scores (188.5 vs 122.4). Clinical deterioration prior to MT occurred in 35% of intermediate-risk patients. Extracorporeal membrane oxygenation (ECMO) consultation rate (32% vs 7%), peri-procedural ECMO use (18% vs 2.3%), major bleeding (27% vs 4.7%), and in-hospital mortality (36% vs 11.6%) were higher in the high-risk group. Thrombus removal was achieved in 77% and 88% of high- and intermediate-risk patients, respectively. High-risk patients had longer ICU (mean 4 vs 1.3 days) and hospital stays (mean 21.5 vs 6.4 days), higher thirty-day mortality (36% vs 14%), and lower 90-day survival (59% vs 79%). Conclusions MT achieved high rates of thrombus removal in both groups. In this retrospective cohort, high-risk patients had greater baseline clinical severity and was associated with higher bleeding rates, greater resource utilization, including ECMO consultation and peri-procedural use, prolonged ICU and hospital stays, as well as increased mortality.

Empirical evidence suggests direct thrombin inhibitors (DTIs) produce more favorable hemostatic outcomes than heparin in patients supported by extracorporeal membrane oxygenation (ECMO), yet the exact mechanisms responsible are unknown. We systematically searched databases and registers for studies comparing DTIs to heparin in humans receiving ECMO. A total of 28 studies were identified, most of which (n = 25) used bivalirudin, while the rest (n = 3) used argatroban. In random-effects meta-analysis, DTIs achieved the therapeutic anticoagulation range faster (mean difference = −6.96 hours, 95% confidence interval [CI] = −11.98 to −1.95, p = 0.006) and maintained the therapeutic range for a greater proportion of time (mean difference = 18.6%, 95% CI = 8.78–28.42, p < 0.001) than heparin. Subgroup analysis revealed these effects were similarly significant in adult patients and when bivalirudin was the DTI; however, they were not significant in pediatric patients or when argatroban was the DTI. Sensitivity analysis confirmed robustness of the primary findings in only low-risk of bias studies and in only studies published as full papers. In summary, DTIs—specifically bivalirudin—were associated with faster time to therapeutic anticoagulation and maintained the goal range for a greater percentage of time than heparin during ECMO support.