Sex Differences in Risk Profile and Outcomes Following Aspiration Thrombectomy for Intermediate-Risk Pulmonary Embolism: Findings From the SYMPHONY-PE IDE Trial

Background Prior studies have shown that women with acute pulmonary embolism (PE) are less likely to receive definitive therapies and experience worse hospital outcomes than men. Whether women have different risk profiles or outcomes after aspiration thrombectomy remains unclear. Methods We evaluated sex-specific differences in patients with acute intermediate-risk PE treated with the Symphony Thrombectomy System in the prospective US Food and Drug Administration–approved SYMPHONY-PE investigational device exemption trialStandardized differences were compared with baseline characteristics. Efficacy outcomes included right ventricular-to-left ventricular (RV/LV) ratio, clot burden measured by the refined modified Miller index (rMMI), pulmonary artery pressure (PAP), and hospital length of stay (LOS). Results Women comprised 39% (43 of 109 patients) of the cohort and more frequently had elevated B-type natriuretic peptide (BNP)/N-terminal pro-BNP (74% vs 55%; P = .04) and troponin (79% vs 29%; P < .01 ) and higher median composite pulmonary embolism shock (CPES) scores (5 vs 4; P < .01), despite similar simplified Pulmonary Embolism Severity Index (sPESI) scores. Baseline RV/LV ratio and thrombus burden were similar. rMMI reduction was similar, but women had a lower 48-hour RV/LV ratio (1.03 ± 0.15 vs 1.14 ± 0.26; P = .006), which persisted after multivariable adjustment, and greater reductions in mean PAP (28% ± 14% vs 19% ± 24%; P = .02) and diastolic PAP (5.9 ± 5.0 vs 3.3 ± 5.9 mm Hg; P = .02). Safety events were rare, with no 30-day deaths. Postprocedural LOS (3 [2-4] days in both groups) and discharge home (98% vs 98%) were similar. Conclusions Despite similar sPESI scores, women had a higher risk profile than men according to CPES scores and clinical biomarkers. Following aspiration thrombectomy, women had comparable clot burden reduction, lower 48-hour RV/LV ratio, and similar LOS and safety outcomes. Large-bore 24F catheters were used in the majority of cases for both sexes, with no significant differences in the rates of bleeding complications. These findings highlight potential sex differences in PE risk profile warranting further investigation to inform treatment selection.