Rationale and design of a randomized, sham-controlled, clinical trial for evaluation of the Edwards APTURE transcatheter shunt system (ALT-FLOW II)
Year: 2026
Type: article
Study design: Study Protocol
Abstract: AIMS: Heart failure (HF) with preserved (HFpEF) and mildly reduced (HFmrEF) ejection fraction are prevalent, yet frequently underdiagnosed syndromes associated with high morbidity and mortality, impaired quality of life, and escalating healthcare expenditures. Although guideline-directed medications like SGLT2 inhibitors have been shown to reduce the risk of hospitalization and cardiovascular death, their use remains limited and substantial residual risk persists. This trial aims to evaluate the safety and performance of a novel left-atrium-to-coronary-sinus shunt (Edwards APTURE transcatheter shunt system) in HFpEF and HFmrEF patients. METHODS: ALT-FLOW II is a prospective multi-centre, randomized, sham-controlled, double-blinded (patient and assessor) trial. Approximately 100 symptomatic HF patients aged ≥18 years with left ventricular ejection fraction >40% and exercise pulmonary capillary wedge pressure (PCWP) ≥25 mm Hg with a PCWP to right atrial pressure gradient ≥8 mm Hg will be randomized 1:1 to the APTURE shunt vs sham control. Key exclusion criteria include severe HF, significant valvular disease, and more than mild right ventricular dysfunction. The primary endpoints are the safety of the APTURE device at 30 days and change in workload-corrected PCWP normalized to bodyweight at 6 months. Secondary endpoints include changes in patient-reported outcomes, and hemodynamic and echocardiographic parameters through 5 years. The trial will also explore the impact of the device on short-term cardiac remodelling and intra-cardiac flow patterns using multi-modality imaging. CONCLUSIONS: The ALT-FLOW II trial will evaluate the safety and performance of the APTURE system in symptomatic HFpEF and HFmrEF patients with elevated left atrial pressure.
DOI: 10.1093/ejhf/xuaf016
Institutions: Christ Hospital, Medical University of South Carolina, Vanderbilt University Medical Center, Main Line Health, Oregon Health & Science University, University Medical Center of the Johannes Gutenberg University Mainz, Mayo Clinic, Massachusetts General Hospital, Baim Institute for Clinical Research, Allina Health, Minneapolis Heart Institute Foundation, Montefiore Medical Center, Montefiore Health System, San Francisco VA Medical Center, University of San Francisco, The Ohio State University, Universitätsklinikum des Saarlandes, Saarland University, University of Bern, University Hospital of Bern, University of Mississippi, Baylor Scott & White Research Institute, Weill Cornell Medicine
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $5,300
Funder: Edwards Lifesciences
OpenAlex ID: W7119501522