Authors: Thomas Tu, Catalin Toma, Victor F. Tapson, Christopher Adams, Wissam A. Jaber, Mitchell Silver, Sameer Khandhar, Rohit Amin, Mitchell Weinberg, Tod Engelhardt, Monica Hunter, David Holmes, Glenn Hoots, Hussam Hamdalla, Robert L. Maholic, Scott M. Lilly, Kenneth Ouriel, Kenneth Rosenfield and for the FLARE Investigators
Summary: Objectives: The aim of this study was to evaluate the safety and effectiveness of percutaneous mechanical thrombectomy using the FlowTriever System (Inari Medical, Irvine, California) in a prospective trial of patients with acute intermediate-risk pulmonary embolism (PE).
Background: Catheter-directed thrombolysis has been shown to improve right ventricular (RV) function in patients with PE. However, catheter-directed thrombolysis increases bleeding risk and many patients with PE have relative and absolute contraindications to thrombolysis.
Methods: Patients with symptomatic, computed tomography–documented PE and RV/left ventricular (LV) ratios ≥0.9 were eligible for enrollment. The primary effectiveness endpoint was core laboratory–assessed change in RV/LV ratio. The primary safety endpoint comprised device-related death, major bleeding, treatment-related clinical deterioration, pulmonary vascular injury, or cardiac injury within 48 h of thrombectomy.
Results: From April 2016 to October 2017, 106 patients were treated with the FlowTriever System at 18 U.S. sites. Two patients (1.9%) received adjunctive thrombolytics and were analyzed separately. Mean procedural time was 94 min; mean intensive care unit stay was 1.5 days. Forty-three patients (41.3%) did not require any intensive care unit stay. At 48 h post-procedure, average RV/LV ratio reduction was 0.38 (25.1%; p < 0.0001). Four patients (3.8%) experienced 6 major adverse events, with 1 patient (1.0%) experiencing major bleeding. One patient (1.0%) died, of undiagnosed breast cancer, through 30-day follow-up.
Conclusions: Percutaneous mechanical thrombectomy with the FlowTriever System appears safe and effective in patients with acute intermediate-risk PE, with significant improvement in RV/LV ratio and minimal major bleeding. Potential advantages include immediate thrombus removal, absence of thrombolytic complications, and reduced need for post-procedural critical care.
Source: JACC: Cardiovascular Interventions; Volume 12, Issue 9, May 2019