Left Atrial-to-Coronary Sinus Shunting in Heart Failure With Mildly Reduced or Preserved Ejection Fraction: The ALT-FLOW Trial (Early Feasibility Study) 2-Year Results.

Background: The ALT-FLOW trial EFS (Early Feasibility Study) evaluated safety, hemodynamics and outcomes for the APTURE system in patients with HF and mildly reduced or preserved ejection fraction.

Objectives: In this study, the authors sought to examine the 2-year health status, functional capacity, and outcomes of ALT-FLOW EFS.

Methods: Device safety, performance, patency, hemodynamics, echocardiographic parameters, and outcomes were assessed in patients with LVEF >40% (n = 95); NYHA functional class, Kansas City Cardiomyopathy Questionnaire (KCCQ) Clinical Summary Score (CSS), Total Symptom Score (TSS), and Overall Summary Score (OSS), 6-minute walk distance, and the ratio of pulmonary capillary wedge pressure at peak exercise to workload normalized to body weight (PCWL) were evaluated.

Results: Major adverse cardiac, cerebral, and renal events and reintervention through 30 days occurred in 2.8% of patients. All implanted shunts were patent for up to 5 years. The mean PCWL decreased from 131 ± 74 mm Hg/W/kg at baseline to 76 ± 57 mm Hg/W/kg after 6 months (P < 0.0001). After 2 years, NYHA functional class improvement was reported in 51/62 patients (82.3%). Mean KCCQ CSS, TSS, and OSS at baseline were 45 ± 17, 46 ± 19, and 38 ± 18 points, respectively, and improved at 2 years by 25 ± 20, 26 ± 23, and 31 ± 23 points, respectively. The reduction in PCWL and improvement in NYHA functional class and KCCQ scores were consistent in patients with or without pulmonary vascular disease. No detrimental changes in right or left ventricular function were observed.

Conclusions: In patients with HF and LVEF >40%, the APTURE shunt confirmed an acceptable safety profile with improvements in HF symptoms, quality of life, and functional capacity without negatively affecting right and left heart function after 2 years, regardless of pulmonary vascular disease. (Exploratory Study of the Edwards APTURE Transcatheter Shunt System [ALT-FLOW Canada]; NCT04000607; Early Feasibility Study-Edwards APTURE Transcatheter Shunt System [ALT-FLOW US]; NCT03523416).