Ultrasound-assisted catheter-directed thrombolysis versus anticoagulation alone in intermediate–high risk pulmonary embolism

Background Ultrasound-assisted catheter-directed thrombolysis (USAT) may enhance right ventricular recovery in intermediate–high-risk pulmonary embolism, but evidence is limited. We compared the safety, efficacy, and net benefit of USAT versus standard anticoagulation. Methods We analyzed a propensity-matched prospective cohort of 432 intermediate-high-risk patients (216 USAT vs 216 anticoagulation) from the Italian USAT-HI and OPTIRAPE registries. Outcomes included all- cause, cardiovascular (CV) and PE-related mortality, major bleedings, and a composite net clinical benefit (NCB), with a day-7 landmark analysis distinguishing early (0–7 days) from late (8–30 days) events. Time-to-event analyses used Kaplan–Meier estimates and Cox regression with Hazard ratios (HRs) and relative 95% confidence intervals (CIs). Results Baseline demographics (mean age 64 ± 12 years; 48% female) and comorbidities were balanced between cohorts. USAT was associated with lower all-cause (7.4% vs 13.9%; HR 0.52, 95% CI 0.28–0.85; p=0.01), cardiovascular (3.2% vs 8.3%; HR 0.39; p<0.001), and PE-related mortality (2.3% vs 6.5%; HR 0.34; p=0.02) compared with anticoagulation. Major bleeding was similar (2.7% vs 1.9%; p=0.56). USAT significantly improved net clinical benefit (13.4% vs 25.9%; HR 0.48, 95% CI 0.30–0.75; p=0.001), mainly driven by reductions in early mortality and clinical deterioration. Landmark analysis indicated that benefits were largely confined to the first 7 days, with favourable but non-significant effects during days 8–30. Conclusions In intermediate–high-risk PE, USAT appears to confer an early survival benefit, improved net clinical outcomes, and a safety profile comparable to standard anticoagulation, supporting its role in rapid right ventricular recovery and early clinical stabilization.