FLASH Registry Assesses Inari’s FlowTriever Mechanical Thrombectomy System for Acute PE

September 18, 2022—Clinical outcomes were presented for the complete nationwide cohort of FLASH, the FlowTriever All-Comer Registry for Patient Safety and Hemodynamics. The FLASH registry is a prospective interventional study of acute pulmonary embolism (PE) patients who received mechanical thrombectomy with the FlowTriever system (Inari Medical, Inc.), which extracts PE thrombus by aspiration and/or mechanical modes without the need for thrombolytics.

Findings from the FLASH registry were reported at TCT 2022, the 34th annual Transcatheter Cardiovascular Therapeutics scientific symposium of the Cardiovascular Research Foundation held September 16-19 in Boston, Massachusetts. The study was simultaneously published online by Catalin Toma, MD, et al in EuroIntervention.

Dr. Toma commented in the TCT press release, “Data from the largest prospective interventional PE study population confirms the safety of the FlowTriever mechanical thrombectomy system. In addition, patients had rapid hemodynamic improvement with the procedure which continued through 6 months of follow up. Ongoing randomized trials including PEERLESS will provide important insights regarding the device’s safety and effectiveness compared to other treatments.” Dr. Toma is Assistant Professor of Medicine, University of Pittsburgh School of Medicine, and Director of Interventional Cardiology, UPMC Heart and Vascular Institute in Pittsburgh, Pennsylvania.

According to the TCT press release, the primary endpoint of the study was a composite of major adverse events (MAE) that included device-related mortality or major bleeding within 48 hours of the procedure, and intraprocedural device- or procedure-related adverse events. The investigators enrolled a total of 800 patients at 50 sites in the United States.

As summarized by TCT, at 48 hours postprocedure, MAEs occurred in 14 (1.8%) patients: two (0.3%) with procedure-related MAEs deemed unrelated to the device; one (0.1%) with a procedure-related MAE of unknown relation to the device; and 11 with major bleeding events (1.4% with no intracranial hemorrhages).

There were no device-related deaths. All-cause mortality was 0.3% at 48-hour follow-up; 0.8% at 30-day follow-up; and 5.0% at 6-month follow-up. Follow-up is ongoing.

TCT also noted that the investigators observed significant on-table hemodynamic improvement at the end of the procedure among patients in whom it was assessed.

• Mean pulmonary arterial pressure decreased from 32.6 mm Hg to 24.9 mm Hg (23.0% for paired assessments; P < .0001).
• Total pulmonary vascular resistance decreased from 6.65 mm Hg to 4.99 mm Hg-min/L (20.1% for paired assessments; P < .0001).
• Cardiac index (CI) increased from 1.64 L/min/m² to 1.93 L/min/m² (18.9% for paired assessments; P < .0001) among patients with depressed CI (< 2.0 L/min/m²) at baseline.