STORM-PE Trial: Mechanical Thrombectomy Shows Superior Heart Function Recovery in Pulmonary Embolism
USA: Results from the pivotal STORM-PE randomized controlled trial, presented as a Late-Breaking Clinical Trial at TCT 2025, have provided the first head-to-head evidence comparing mechanical thrombectomy (MT) combined with anticoagulation (AC) against anticoagulation alone in patients with acute intermediate-high-risk pulmonary embolism (PE).
The findings highlight that computer-assisted vacuum thrombectomy (CAVT) offers meaningful improvements in right-heart function while maintaining a strong safety profile, marking a major advancement in the treatment of this serious condition.
Pulmonary embolism remains a major cause of cardiovascular mortality. While anticoagulation is the standard treatment, patients with intermediate-high-risk PE—characterized by right ventricular dysfunction and elevated biomarkers—remain vulnerable to clinical worsening. Mechanical thrombectomy offers a catheter-based option to remove clot burden without the bleeding risks of thrombolysis, but until now, randomized evidence comparing it with anticoagulation alone has been lacking.
The STORM-PE trial enrolled around 100 patients across multiple centers who were randomly assigned to receive either anticoagulation alone or anticoagulation in combination with CAVT using the Indigo Aspiration System with Lightning Flash technology. All imaging assessments were reviewed by an independent core laboratory blinded to treatment allocation.
The primary endpoint was the change in right-to-left ventricular (RV/LV) ratio at 48 hours, an established marker of right-heart strain and predictor of PE outcomes, while secondary endpoints included changes in pulmonary artery pressure, clinical deterioration, and major adverse events.
The trial led to the following findings:
- Patients treated with thrombectomy showed a significantly greater reduction in the RV/LV ratio at 48 hours compared with those receiving anticoagulation alone, indicating superior improvement in right ventricular function and pulmonary hemodynamics.
- The thrombectomy group also demonstrated a greater decrease in pulmonary artery pressure, highlighting the physiological advantage of effective clot removal.
- Despite improved efficacy, the safety profile remained comparable between the two groups, with no increase in major bleeding, device-related, or procedural complications among those undergoing thrombectomy.
- The study included 100 patients (mean age around 60 years; 46% women) who had acute PE symptoms for less than 14 days, imaging-confirmed thrombus in a main or lobar pulmonary artery, and elevated cardiac biomarkers.
- Median thrombectomy time was 25 minutes, and total procedure time averaged 56 minutes, demonstrating procedural efficiency.
- Technical success was achieved in all cases, with no device-related transfusions or access-site complications reported.
- Median hospital stays were short, and most patients achieved early clinical stability after the procedure.
- At 48 hours, the mean RV/LV ratio reduction was 0.52 with thrombectomy compared to 0.24 with anticoagulation alone.
- A higher proportion of patients achieved an RV/LV ratio decrease greater than 0.2 in the thrombectomy group (79.3%) than in the anticoagulation-only group (51.9%).
- The composite rate of major adverse events within seven days—including mortality, recurrent PE, and major bleeding—was low in both arms (4.3% vs 7.5%), with no procedure-related deaths reported.
Experts presenting the findings noted that these results support the growing role of mechanical thrombectomy as an early interventional strategy for intermediate-high-risk PE, providing rapid hemodynamic improvement without additional bleeding risk. By demonstrating both superior efficacy and comparable safety, the STORM-PE trial paves the way for mechanical thrombectomy to become an integral component of pulmonary embolism management, bridging the gap between standard anticoagulation and high-risk thrombolytic therapy.
Reference:
Lookstein R. Randomized controlled trial of mechanical thrombectomy with anticoagulation versus anticoagulation alone for acute intermediate-high risk pulmonary embolism: primary results from STORM-PE. Presented at: TCT 2025. October 26, 2025. San Francisco, CA.
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