RecentRCT

PEERLESS

Large-Bore Mechanical Thrombectomy Versus Catheter-Directed Thrombolysis in the Management of Intermediate-Risk Pulmonary Embolism: Primary Results of the PEERLESS Randomized Controlled Trial

Circulation, 2025 · Multicenter randomized controlled trial (n=550)

Clinical question

In intermediate-risk acute PE selected for intervention, how does large-bore mechanical thrombectomy compare with catheter-directed thrombolysis?

Population: Adults with intermediate-risk acute pulmonary embolism selected for catheter-based intervention
Intervention: Large-bore mechanical thrombectomy
Comparator: Catheter-directed thrombolysis
Primary outcome: Hierarchical composite of all-cause mortality, intracranial hemorrhage, major bleeding, clinical deterioration/bailout, and postprocedural ICU utilization through discharge or 7 days
Result: The hierarchical primary endpoint favored large-bore thrombectomy (win ratio 5.01, 95% CI 3.68–6.97; P<0.001), driven mainly by less clinical deterioration/bailout and less ICU utilization. Mortality, intracranial hemorrhage, and major bleeding were not significantly different; 30-day mortality was 0.4% versus 0.8%. (Win ratio 5.01 (95% CI 3.68–6.97), P<0.001)

What the trial found

Among intervention-selected intermediate-risk PE patients, large-bore thrombectomy improved the prespecified hierarchical composite compared with catheter-directed thrombolysis, largely through less deterioration/bailout and ICU use rather than a demonstrated mortality advantage.

Current guideline position

The 2026 U.S. PE guideline uses clinical category, deterioration, bleeding risk, anatomy, local expertise, and patient preference to select advanced therapies rather than declaring one catheter strategy universally superior.

Clinical interpretation

PEERLESS supports large-bore thrombectomy as an effective catheter-based option in appropriately selected intermediate-risk PE, but it does not establish a mortality benefit or justify routine intervention for all stable intermediate-risk PE.

Limitations

Open-label procedural trial in patients already selected for intervention.
The hierarchical primary endpoint was strongly influenced by deterioration/bailout and ICU-utilization components.
The trial was not powered to demonstrate a mortality difference.

Moderate certainty

Clinical Context & Relevant Topics (1)

Disease Reference

Acute Pulmonary Embolism

Pulmonary vascular occlusion, acute RV pressure overload, ESC/AHA risk stratification, systemic thrombolysis, catheter-directed therapies, and hemodynamic support.

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