Data from the PEERLESS registry cohort suggests that large-bore mechanical thrombectomy (LBMT) is safe and effective for intermediate-risk pulmonary embolism (PE) patients unable to receive thrombolytics. According to the new findings, there were no in-hospital deaths or intracranial hemorrhage events through discharge or seven days post-procedure. Additionally, the major bleeding rate was around 4%, which is comparable to findings observed in randomized patients. “These results substantiate the safety and effectiveness of LBMT for intermediate-risk PE in patients with a high risk of bleeding," said Stefan Stortecky, MD, Senior Consultant of Interventional Cardiology at the Swiss Cardiovascular Center, Bern, Switzerland. Treatment option Presented for the first time, these results may offer another solution for patients who have limited treatment options. Up to one in three PE patients are ineligible for thrombolytics due to bleeding risks and other contraindications. The PEERLESS trial previously demonstrated that LBMT was superior to catheter-directed thrombolysis (CDT) for treating intermediate-risk PE. Presenting at Cardiovascular Research Technologies (CRT) 2025, Dr. Stortecky said that, despite the registry cohort’s significant medical histories and higher baseline risk, LBMT was performed successfully without increased mortality or major complications. Concluding thoughts Further findings from the cohort, consisting of 142 patients, revealed the hemodynamic improvements observed with LBMT with a mean pulmonary artery pressure reduction of 6.6 mmHg (20.5%) and a mean right ventricle/left ventricle (RV/LV) ratio reduction of 0.38 (26.1%). Additionally, 62.5% of patients demonstrated normal or mildly reduced right ventricular function at 24 hours post-procedure. "Despite these findings, LBMT was performed in the registry cohort with no in-hospital mortality or intracranial hemorrhage events, a major bleeding rate equivalent to that observed in randomized patients, and the same degree of improvement in clinical and imaging outcomes," Dr. Stortecky concluded during Tuesday’s Late-Breaking Clinical Trials session. Investigative approach The prospective PEERLESS registry cohort enrolled 142 patients across 37 sites in the United States, Germany and Switzerland. The mean age of patients was approximately 63 years, and the cohort included both male and female patients. Specific sex distribution data were not disclosed. Patients underwent LBMT using the FlowTriever System (Inari Medical), a catheter-based device designed to remove large clots without the need for thrombolytics. The primary safety endpoint was defined as in-hospital mortality, intracranial hemorrhage (ICH) and major bleeding events through discharge or seven days post-procedure. Image Credit: Bailey G. Salimes Image Caption: Stefan Stortecky, MD, presents during a Late-Breaking Clinical Trial session at Cardiovascular Research Technologies (CRT) 2025 on Tuesday.