Mechanical Thrombectomy Versus Anticoagulation in Intermediate-Risk Pulmonary Embolism: A Risk-Stratified, Propensity Score-Matched Analysis.

OBJECTIVES

To compare 1-year all-cause mortality and long-term cardiopulmonary outcomes in intermediate-risk pulmonary embolism (PE) treated with mechanical thrombectomy (MT) versus anticoagulation (AC).

BACKGROUND

Whether MT confers a survival advantage-and whether this benefit differs across intermediate risk PE subgroups remains unknown.

METHODS

Retrospective, 1:1 propensity score-matched cohort study using the TriNetX Analytics Network (2010-2026). Adults with acute PE were stratified into low-intermediate (corresponding to AHA/ACC PE Category C1-C2 in the 2026 AHA/ACC PE Guideline) and high-intermediate (corresponding to AHA/ACC PE Category C3) risk subgroups. The primary endpoint was all-cause mortality at 365 days. Secondary endpoints included new-onset pulmonary hypertension, right heart failure, acute respiratory failure, and bleeding. IRB waiver was applicable per HIPAA de-identification standards.

RESULTS

After matching, 2717 patients per arm were included in the low-intermediate risk cohort and 1150 per arm in the high-intermediate risk cohort. MT was associated with lower 1-year all-cause mortality in both subgroups: low-intermediate risk (11.0% vs. 17.8%; HR 0.642 [95% CI 0.556-0.741]; p < 0.001) and high-intermediate risk (7.0% vs. 11.0%; HR 0.631 [95% CI 0.475-0.839]; p = 0.002). In low-intermediate risk PE, MT was associated with increased pulmonary hypertension (HR 1.578; p < 0.001) and right heart failure (HR 4.473; p < 0.001). In high-intermediate risk PE, MT reduced pulmonary hypertension (HR 0.764; p = 0.044) and bleeding (HR 0.744; p = 0.048).

CONCLUSIONS

MT was associated with reduced 1-year mortality compared with AC alone in intermediate-risk PE. The net clinical benefit is risk-profile dependent: MT appears favorable in high-intermediate risk (AHA/ACC Category C3-equivalent) PE, whereas in low-intermediate risk (AHA/ACC Category C1-C2-equivalent) PE the apparent survival advantage is offset by elevated rates of pulmonary hypertension and right heart failure. These findings are hypothesis-generating and require validation in adequately powered randomized controlled trials with pre-specified long-term mortality endpoints.