For patients with intermediate-high risk pulmonary embolism (PE), a new trial suggests that mechanical thrombectomy plus anticoagulation is superior to anticoagulation alone in improving right ventricular (RV) function, with a comparable safety profile. The primary results from the STORM-PE trial show that computer-assisted vacuum thrombectomy (CAVT) led to a significantly greater reduction in the RV to left ventricular (LV) diameter ratio at 48 hours.¹

Mechanism of Action

CAVT is an endovascular therapy that utilises a microprocessor-driven algorithm designed to aspirate thrombus from the pulmonary arteries while minimising blood loss. The aim is to rapidly relieve acute RV pressure overload and normalise haemodynamics in patients with PE.²

Methodology

The STORM-PE trial was an international, multicentre, randomised controlled trial that enrolled 100 patients across 22 sites. Eligible participants were normotensive adults with acute (symptoms ≤14 days) intermediate-high risk PE, confirmed by a RV/LV ratio ≥1.0 on computed tomographic pulmonary angiography (CTPA) and elevated cardiac biomarkers.

Patients were randomised 1:1 to receive either CAVT with anticoagulation (n=47) or anticoagulation alone (n=53). The primary endpoint was the change in RV/LV ratio at 48 hours. The main secondary endpoint was a composite of major adverse events (MAEs) within 7 days, including clinical deterioration requiring rescue therapy, PE-related mortality, symptomatic recurrent PE, and major bleeding.

Results/Top Line Results/Findings

The trial met its primary endpoint. At 48 hours, the mean reduction in RV/LV ratio was significantly greater in the CAVT group compared to the anticoagulation-alone group (0.52 vs 0.24, respectively; difference of 0.27; p<0.001).¹ Patients treated with CAVT also experienced more frequent normalisation of vital signs within 48 hours and a greater reduction in pulmonary artery obstruction, as measured by modified Miller scores (p<0.001).

The rate of the composite secondary safety endpoint at 7 days was not significantly different between the groups (4.3% for CAVT vs 7.5% for anticoagulation; p=0.681). There were two PE-related deaths in the CAVT arm, which were adjudicated as not being related to the device or procedure. Major bleeding occurred in one patient in each arm.

In Practice/Interpretation/Take-Home Messages

These findings suggest that for patients with intermediate-high risk PE, the addition of CAVT to standard anticoagulation can lead to more rapid improvement in RV strain. According to the investigators, “CAVT was superior to anticoagulation alone in reducing RV/LV ratio within 48 hours in patients with intermediate-high risk PE, accompanied by earlier normalisation of vital signs and major adverse event rates comparable to those for anticoagulation.”¹

Next Steps/Information About the Trial

While STORM-PE provides important data, the trial was not powered for clinical outcomes beyond the surrogate endpoint of RV/LV ratio. The authors note that ongoing randomised trials will further clarify the long-term risks and benefits of mechanical thrombectomy in this patient population.

This study was funded by Penumbra, Inc.

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References

1. Lookstein RA, Konstantinides SV, Weinberg I, 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. https://doi.org/10.1161/CIRCULATIONAHA.125.077232.

2. Konstantinides SV, Meyer G. The 2019 ESC guidelines on the diagnosis and management of acute pulmonary embolism. Eur Heart J. 2019;40:3453–3455. https://doi.org/10.1093/eurheartj/ehz726.