Large-Bore Mechanical Thrombectomy Versus Catheter-Directed Thrombolysis
PEERLESS trial design and results
Design
Randomised controlled trial with a hierarchical win-ratio primary endpoint
Treatment
Large-bore mechanical thrombectomy
Control
Catheter-directed thrombolysis
Population
Patients with intermediate-risk pulmonary embolism
Follow-up
In-hospital and 30 days
Primary endpoint
Hierarchical composite of mortality, intracranial haemorrhage, major bleeding, clinical deterioration or bailout, and intensive care use, analysed as a win ratio
Result
Win ratio 5.01 (95% CI 3.68 to 6.97, p<0.001) favouring thrombectomy. Clinical deterioration or bailout occurred in 1.8% versus 5.4% (p=0.04). Postprocedural intensive care admission 41.6% versus 98.6%, and stays over 24 hours 19.3% versus 64.5% (p<0.001). No significant difference in mortality, intracranial haemorrhage or major bleeding.
Secondary endpoints
Mortality, intracranial haemorrhage, major bleeding, intensive care use
PEERLESS met its primary end point in favor of LBMT compared with CDT in treatment of intermediate-risk pulmonary embolism. LBMT had lower rates of clinical deterioration and/or bailout and postprocedural intensive care unit use compared with CDT, with no difference in mortality or bleeding.
The trial authors, in the published abstract
How it has aged
Read the win ratio carefully: the 5.01 is impressive but the components doing the work are intensive care use and bailout, not death or bleeding. It is a real argument about resource use and deterioration, and it is not evidence that either catheter approach saves lives — a question PEITHO leaves open for this population.
Publications
Large-Bore Mechanical Thrombectomy Versus Catheter-Directed Thrombolysis in the Management of Intermediate-Risk Pulmonary Embolism: Primary Results of the PEERLESS Randomized Controlled Trial
Jaber WA, Gonsalves CF, Stortecky S, et al. 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 Feb 4;151(5):260-273.
Win ratio 5.01 favouring mechanical thrombectomy
Postprocedural ICU admission fell from 98.6% to 41.6%
No difference in mortality, intracranial haemorrhage or major bleeding