Full results from the ENGULF pivotal study of the Hēlo thrombectomy system (Endovascular Engineering) in acute intermediate risk pulmonary embolism (PE) patients demonstrated a 0.95% major adverse event rate (MAE) at 48 hours and 25.1% reduction in right-to-left ventricular (RV/LV) ratio, meeting both its primary safety and efficacy endpoints “by a wide margin”, investigators reveal.
Data from the prospective, single-arm, multicentre investigational device exemption (IDE) study were presented by Andrew Klein (Piedmont Hospital, Atlanta, USA), an ENGULF co-principal investigator, this morning during the 2025 Vascular Interventional Advances (VIVA) conference (November 2–5; Las Vegas, USA).
ENGULF was conducted at 19 leading U.S. centers and enrolled 105 patients in the intention-to-treat population, with a median of two cases carried out per operator. The study demonstrated that the Hēlo system offers a single-pass procedure and has workflow integrated blood-return capabilities, Klein told VIVA 2025. Secondary endpoints showed substantial clinical benefit, he said, with a 16.6% reduction in systolic pulmonary artery pressure, a 16.9% reduction in mean pulmonary artery pressure, and a 16.2% reduction in Modified Miller score. The introduction of a blood return system during the trial reduced median blood loss from 340mL to 10mL.
There was no major bleeding, pulmonary vascular injury or cardiac injury at 48 hours, Klein added. At 30 days, all-cause mortality was 2.85%, device-related serious adverse events was 2.85%, and symptomatic PE recurrence was 3.80%.
There were “zero device-related haemodynamic deteriorations or death”, he said.
The Hēlo system represents a breakthrough in clot removal technology, featuring a unique combination of a 24Fr clot engagement zone and 15Fr heart crossing profile that integrates aspiration with advanced clot remodeling, according to Klein.
