STORM-PE Trial Shows Mechanical Thrombectomy Superior to Anticoagulation Alone for Pulmonary Embolism
Key Insights
The STORM-PE randomized controlled trial demonstrated that computer-assisted vacuum thrombectomy (search) (CAVT) plus anticoagulation (search) significantly reduced right heart strain compared to anticoagulation alone in intermediate-high risk pulmonary embolism (search) patients.
Patients receiving CAVT showed 2.7 times greater thrombus burden reduction, improved physiological recovery with lower heart rates, and 2.2 times greater likelihood of functional status recovery.
The trial enrolled 100 patients across 22 international sites and represents the first randomized study comparing mechanical thrombectomy to standard anticoagulation (search) therapy for pulmonary embolism (search).
The landmark STORM-PE randomized controlled trial has demonstrated that computer-assisted vacuum thrombectomy (search) (CAVT) combined with anticoagulation (search) significantly outperforms anticoagulation alone in treating patients with acute intermediate-high risk pulmonary embolism (search) (PE). The results, presented at the VIVA 2025 Conference and published in Circulation, mark a potential paradigm shift in PE treatment.
Superior Clinical Outcomes with Mechanical Intervention
The 22-site international trial enrolled 100 patients with acute intermediate-high risk PE and found that those treated with CAVT plus anticoagulation (search) achieved a significantly greater reduction in right heart strain. The primary endpoint showed a mean RV/LV ratio (search) reduction of 0.52 with CAVT compared to 0.24 with anticoagulation alone (P < 0.001), representing a 29.7% versus 13.1% relative reduction.
"The latest STORM-PE findings demonstrate substantial improvements in both clinical and functional outcomes, with a significantly higher proportion of patients treated with CAVT plus anticoagulation (search) returning to normalization within 48 hours compared to anticoagulation alone—a remarkable result," said Dr. Rachel Rosovsky, co-global principal investigator and hematologist at Massachusetts General Hospital.
Enhanced Thrombus Clearance and Physiological Recovery
Patients receiving CAVT demonstrated markedly superior thrombus burden reduction, with a 2.7 times larger decrease in refined modified Miller score (42.1% vs. 15.6% relative reduction; P < 0.001). The intervention also produced significant early physiological improvements at 48 hours, including lower heart rates (80.0 bpm vs 86.4 bpm; P = 0.022), reduced tachycardia rates (2.2% vs 20%; P = 0.008), and decreased supplemental oxygen requirements (0.5 L/min vs 1.4 L/min; P = 0.027).
The NEWS2 risk score for clinical deterioration was also significantly lower in the CAVT group (1.8 vs. 2.7; P = 0.034), indicating better overall clinical stability.
Functional Recovery Advantages
Beyond immediate clinical improvements, CAVT patients showed superior functional recovery outcomes. They demonstrated a 2.2 times greater likelihood of progressing toward recovery of functional status based on post-venous thromboembolism (search) functional status scores from pre-PE event to discharge (P = 0.032).
At 90 days, CAVT patients walked significantly longer distances during six-minute walk tests (472m vs 376m; P = 0.019) and achieved near-normalization, walking 94% of their predicted distance compared to 75% in the anticoagulation (search)-only group (P = 0.022).
Comparable Safety Profile
Safety analysis through 90 days revealed comparable rates between treatment groups, with major adverse events occurring in 4.3% of CAVT patients versus 7.5% of anticoagulation (search) patients within 7 days. The trial reported no device-related mortality, no additional PE-related mortality beyond 7 days, and no difference in symptomatic PE recurrence.
Technical success with CAVT was 100%, with a median thrombectomy time of 25 minutes and median procedure time of 56 minutes. No device- or procedure-related transfusions or access-site complications occurred.
Clinical Significance and Future Impact
"This is a foundational trial that will significantly advance PE care, allowing these advanced therapies to be offered to more patients, improving patient outcomes, and potentially leading to the inclusion in future treatment guidelines," said Dr. Robert Lookstein, co-global principal investigator and professor at Icahn School of Medicine at Mount Sinai.
The study utilized Penumbra's Lightning Flash (search) system with CAVT technology, which became commercially available in 2023. Dr. Kenneth Rosenfield of Massachusetts General Hospital, serving as discussant, noted that despite the relatively small sample size of 100 patients, "the results are highly significant, demonstrating the enormous impact of this therapy."
Addressing Unmet Medical Need
Pulmonary embolism (search) represents a significant healthcare burden, with an estimated 900,000 cases of venous thromboembolism (search) occurring annually in the United States. PE is the third leading cause of cardiovascular death after heart attack and stroke, highlighting the critical need for improved treatment options.
The STORM-PE trial represents the first randomized study to compare mechanical thrombectomy with the current standard of care, providing the strongest evidence to date for advanced intervention in intermediate-high risk PE patients. The RV/LV ratio (search) endpoint, while a surrogate measure, has been previously linked to prognosis, with ratios ≥ 1.0 associated with more than twofold increased risk of early death.