STORM‑PE: First Randomized Trial of Mechanical Thrombectomy + Anticoagulation vs Anticoagulation Alone

Background & Rationale

• Patients with intermediate‑high‑risk PE (normotensive but with right ventricular (RV) strain and elevated biomarkers) have uncertain optimal management—balancing risks and benefits of intervening beyond anticoagulation.

• Prior studies of catheter‑directed thrombolysis or mechanical thrombectomy were mostly single‑arm or compared against other interventions, not vs anticoagulation alone.

• STORM‑PE was designed to finally fill that gap with a head‑to‑head randomized comparison.

  
  

Study Design

• Type: Prospective, multicenter, randomized controlled trial.

• Participants: 100 patients with intermediate‑high‑risk acute PE (RV/LV ratio ≥1.0 on CT and elevated troponin/BNP).

• Interventions:

  • CAVT + Anticoagulation: Computer‑assisted vacuum thrombectomy (Penumbra Lightning Flash™) plus standard anticoagulation.

  • Anticoagulation Alone: Standard systemic anticoagulant therapy.

• Primary Endpoint: Change in RV/LV ratio on CT at 48 hours—a surrogate for right heart strain relief.

• Secondary Metrics: Major adverse events, early physiologic changes, functional outcomes (e.g., 6‑minute walk distance), quality of life scores, 90‑day outcomes.

  
  

Key Findings

Right Heart Function & Physiology

• RV/LV Ratio Reduction (48 hrs): Significantly greater with mechanical thrombectomy + anticoagulation vs anticoagulation alone (mean ~0.52 vs ~0.24; p<0.001).

  Proportion Achieving RV/LV Normalization: Much higher in the thrombectomy group (~39% vs ~13%).

  
  

Early Clinical & Physiologic Improvements

• Patients treated with thrombectomy had more robust physiologic recovery at 48 hours:

  • Lower heart rates and less tachycardia.

  • Reduced supplemental oxygen needs.

  • Lower NEWS2 scores predicting clinical deterioration.

    
    

Functional Outcomes

• In reported analyses, thrombectomy patients walked significantly farther at 90 days (e.g., ~472 m vs ~376 m; p = 0.019) and came closer to predicted walk distances, suggesting real functional benefit.

  
  

Safety

• No statistically significant increase in major adverse events or major bleeding with thrombectomy vs anticoagulation alone in the early follow‑up period.

  
  

What This Means Clinically

1. Confirmed physiologic benefit with thrombectomy

• STORM‑PE is the first randomized evidence that mechanical thrombectomy significantly improves right ventricular strain relative to anticoagulation alone in intermediate‑high‑risk PE.

2. Safety profile is reassuring

• No signal of excess procedural major bleeding or adverse events, at least in the short–mid‑term.

3. Mortality and long‑term outcomes still undefined

• The trial was not powered for mortality, long‑term survival, or major clinical endpoints such as recurrent PE or quality of life beyond surrogate and functional measures.

4. May influence guideline evolution

• These results provide level‑1 support for a more aggressive early intervention strategy in select intermediate‑high‑risk PE patients, potentially reshaping clinical pathways where thrombectomy is available.

How STORM‑PE Compares to Prior Studies

• Prior RCTs (e.g., PEERLESS) generally compared one invasive intervention to another (e.g., mechanical thrombectomy vs catheter‑directed thrombolysis), not against anticoagulation alone.

• Some single‑arm or registry studies showed physiologic improvements but were limited by design. STORM‑PE now fills the evidence gap by directly comparing to standard care.

Interpretation & Practical Takeaway

• For intermediate‑high risk PE (with imaging and biomarker evidence of right strain), STORM‑PE shows mechanical thrombectomy can rapidly and safely reduce right heart strain and improve early functional recovery compared with anticoagulation alone.

• However, it does not yet prove a mortality benefit or definitive long‑term superiority in all patient‑centered outcomes.

• Treatment decisions should still be individualized, weighing patient comorbidities, bleeding risk, availability of expertise and devices, and clinical trajectory.

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References

1. Lookstein RA, Konstantinides SV, Weinberg I, Dohad SY, Rosol Z, Kopeć G, Moriarty JM, Parikh SA, Holden A, Channick RN, McDonald B, Nagarsheth KH, Yamada K, Rosovsky RP; STORM-PE Trial Investigators. 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. 2025 Nov 3. doi: 10.1161/CIRCULATIONAHA.125.077232. Epub ahead of print. PMID: 41183181.