ALT FLOW: APTURE Transcatheter Shunt System Found Safe in Symptomatic HF Patients

Left atrial to coronary sinus shunting using the APTURE transcatheter shunt system was found to be safe in patients with symptomatic heart failure (HF), resulting in reduction in pulmonary capillary wedge pressure (PCWP) as well as improvement in HF symptoms and quality of life, according to findings from the ALT FLOW Early Feasibility Study, a single-arm, late-breaking clinical trial presented at THT 2023 and simultaneously published in JACC: Cardiovascular Interventions.

Benjamin Hibbert, MD, PhD, et al., enrolled 87 patients from 18 centers with symptomatic HF and PCWP >15 mm Hg at rest or 25 mm Hg during exercise (mean age 71, 53% male) to undergo attempted APTURE shunt implantation. Of the participants, 90% were considered NYHA class III, and the baseline mean left ventricular ejection fraction was 59%.

The device was successful in 90% of patients, indicating no device occlusions or associated adverse events occurring following implantation. The primary safety outcome, defined as a composite of major adverse cardiac, cerebrovascular or renal events and reintervention for study device-related complications at 30 days, was observed in 2.3% of patients.

At six-month follow-up, 68% of patients saw an improvement in health status, achieving NYHA Class I-II and a 23-point improvement (95% CI,17 to 29; p<0.0001) in the Kansas City Cardiomyopathy Questionnaire score. Participants also showed an improvement in 20-watt exercise PCWP, which was –7 mm Hg lower (95% CI –11 to –4; p<0.0001).

Researchers noted a "low but important" rate of safety events, coming from two device embolizations, along with a "less-than-optimal" success rate of 90%, adding that this study represents a first-in-human experience, resulting in "pioneering learning curves."

They identified small sample size and lack of a control group as limitations, and based on the results of this initial investigation, a more definitive trial is being planned with a sham-control arm and randomization.

"It is noteworthy that the one and six-month outcome improvements in the objective measure of PCWP were concordant with the subjective patient-reported improvements in [Kansas City Cardiomyopathy Questionnaire] scores, and without evidence of increased strain on the [right ventricle] or pulmonary vasculature as assessed by hemodynamics and echocardiology," the study authors write.

Clinical Topics: Heart Failure and Cardiomyopathies, Acute Heart Failure

Keywords: Stroke Volume, Ventricular Function, Left, Quality of Life, Feasibility Studies, Sample Size, Follow-Up Studies, Kansas, Random Allocation, Heart Failure, Hemodynamics, Cardiomyopathies, Surveys and Questionnaires

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