MECHANICAL thrombectomy significantly improved right ventricular function compared with anticoagulation alone in patients with intermediate-high risk pulmonary embolism, according to results from the randomised STORM-PE trial.
Unmet Need in Intermediate-High Risk Pulmonary Embolism
Patients with pulmonary embolism often experience acute right ventricular pressure overload, placing them at risk of early haemodynamic deterioration and death. Those classified as intermediate-high risk pulmonary embolism are normotensive but have evidence of right ventricular dysfunction and myocardial injury. Reperfusion strategies aim to rapidly relieve obstruction and restore cardiopulmonary stability. STORM-PE, a prospective international randomised controlled trial, is the first study to compare anticoagulation alone with anticoagulation plus mechanical thrombectomy using computer-assisted vacuum thrombectomy. The trial enrolled adults with acute symptom onset of 14 days or fewer, a right ventricular to left ventricular diameter ratio of at least 1.0 on computed tomographic pulmonary angiography, and elevated cardiac biomarkers.
Trial Design and Primary Endpoint
STORM-PE randomised 100 patients across 22 sites in a 1:1 ratio to computer-assisted vacuum thrombectomy with anticoagulation or anticoagulation alone. The primary endpoint assessed the change in right ventricular to left ventricular ratio at 48 hours, measured by a blinded independent imaging core laboratory. Baseline characteristics were comparable between treatment arms. At 48 hours, the mean reduction in right ventricular to left ventricular ratio was greater in the mechanical thrombectomy group than in the anticoagulation group: 0.52±0.37 versus 0.24±0.40, with a between-group difference of 0.27 (95% CI: 0.12–0.43; p<0.001). Measures of pulmonary artery obstruction, including refined modified and modified Miller scores, also showed significantly greater improvement following mechanical thrombectomy.
Safety and Clinical Implications
Early normalisation of vital signs within 48 hours occurred more frequently in patients treated with mechanical thrombectomy. Major adverse events within 7 days were similar between groups: 4.3% with mechanical thrombectomy versus 7.5% with anticoagulation alone; p=0.681. Two pulmonary embolism related deaths occurred in the mechanical thrombectomy arm. Overall, the findings demonstrate that mechanical thrombectomy achieved superior early reduction in right ventricular strain with comparable short-term safety. These data support further evaluation of mechanical thrombectomy as a reperfusion option for selected patients with intermediate-high risk pulmonary embolism.
Reference
Lookstein RA et al. Randomized controlled trial of mechanical thrombectomy with anticoagulation versus anticoagulation alone for acute intermediate-high risk pulmonary embolism: primary outcomes from the STORM-PE trial. Circulation. 2026;153(1):21-34.
