Large-Bore Mechanical Thrombectomy Versus Catheter-Directed Thrombolysis in the Management of Intermediate-Risk Pulmonary Embolism: Primary Results of the PEERLESS Randomized Controlled Trial
Authors: Jaber Wissam A. , Gonsalves Carin F. , Stortecky Stefan , Horr Samuel , Pappas Orestis , Gandhi Ripal T. , Pereira Keith , Giri Jay , Khandhar Sameer J. , Ammar Khawaja Afzal , Lasorda David M. , Stegman Brian , Busch Lucas , Dexter David J. , Azene Ezana M. , Daga Nikhil , Elmasri Fakhir , Kunavarapu Chandra R. , Rea Mark E. , Rossi Joseph S. , Campbell Joseph , Lindquist Jonathan , Raskin Adam , Smith Jason C. , Tamlyn Thomas M. , Hernandez Gabriel A. , Rali Parth , Schmidt Torrey R. , Bruckel Jeffrey T. , Camacho Juan C. , Li Jun , Selim Samy , Toma Catalin , Basra Sukhdeep Singh , Bergmark Brian A. , Khalsa Bhavraj , Zlotnick David M. , Castle Jordan , O’Connor David J. , Gibson C. Michael ,   for the PEERLESS Committees and Investigators*
Published: October 2024

BACKGROUND:
There are a lack of randomized controlled trial data comparing outcomes of different catheter-based interventions for intermediate-risk pulmonary embolism.

METHODS:
PEERLESS is a prospective, multicenter, randomized controlled trial that enrolled 550 patients with intermediate-risk pulmonary embolism with right ventricular dilatation and additional clinical risk factors randomized 1:1 to treatment with large-bore mechanical thrombectomy (LBMT) or catheter-directed thrombolysis (CDT). The primary end point was a hierarchal win ratio composite of the following (assessed at the sooner of hospital discharge or 7 days after the procedure): (1) all-cause mortality, (2) intracranial hemorrhage, (3) major bleeding, (4) clinical deterioration and/or escalation to bailout, and (5) postprocedural intensive care unit admission and length of stay. Assessments at the 24-hour visit included respiratory rate, modified Medical Research Council dyspnea score, New York Heart Association classification, right ventricle/left ventricle ratio reduction, and right ventricular function. End points through 30 days included total hospital stay, all-cause readmission, and all-cause mortality.

RESULTS:

The primary end point occurred significantly less frequently with LBMT compared with CDT (win ratio, 5.01 [95% CI, 3.68–6.97];
P
<0.001). There were significantly fewer episodes of clinical deterioration and/or bailout (1.8% versus 5.4%;
P
=0.04) with LBMT compared with CDT and less postprocedural intensive care unit use (
P
<0.001), including admissions (41.6% versus 98.6%) and stays >24 hours (19.3% versus 64.5%). There were no significant differences in mortality, intracranial hemorrhage, or major bleeding between strategies or in a secondary win ratio end point including the first 4 components (win ratio, 1.34 [95% CI, 0.78–2.35];
P
=0.30). At the 24-hour visit, respiratory rate was lower for patients treated with LBMT (18.3±3.3 versus 20.1±5.1;
P
<0.001), and fewer had moderate to severe modified Medical Research Council dyspnea scores (13.5% versus 26.4%;
P
<0.001), New York Heart Association classifications (16.3% versus 27.4%;
P
=0.002), and right ventricular dysfunction (42.1% versus 57.9%;
P
=0.004). Right ventricle/left ventricle ratio reduction was similar (0.32±0.24 versus 0.30±0.26;
P
=0.55). Patients treated with LBMT had shorter total hospital stays (4.5±2.8 overnights versus 5.3±3.9 overnights;
P
=0.002) and fewer all-cause readmissions (3.2% versus 7.9%;
P
=0.03), whereas 30-day mortality was similar (0.4% versus 0.8%;
P
=0.62).

CONCLUSIONS:
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.

REGISTRATION:

URL:
https://www.clinicaltrials.gov
; Unique identifier: NCT05111613.