Prospective multicentre single-arm study of an interatrial shunt in heart failure with reduced ejection fraction (SUSTAIN-HF): 1-year clinical and haemodynamic outcomes

BACKGROUND: Evidence for atrial shunt devices in heart failure with reduced ejection fraction (HFrEF) is limited. This study aimed to evaluate the 1-year clinical and haemodynamic outcomes associated with an atrial shunt device in this population. METHODS: In this prospective, multicentre, single-arm cohort study of an interatrial shunt in heart failure with reduced ejection fraction (SUSTAIN-HF), 120 symptomatic HFrEF patients (left ventricular ejection fraction; LVEF ≤40%) on guideline-directed medical therapy were enrolled across 16 centres in China. The intervention was implantation of the D-Shant atrial shunt device. Prespecified primary outcomes were the changes from baseline to 1 year in 6 min walk distance (6MWD) and New York Heart Association (NYHA) functional class. Secondary outcomes included quality of life (Kansas City Cardiomyopathy Questionnaire; KCCQ), echocardiographic parameters and adjudicated adverse events. RESULTS: Between October 2017 and December 2021, 120 patients were enrolled. At 1-year follow-up, implantation of the shunt device was associated with significant improvements in clinical outcomes. The mean 6MWD increased by 54.1 m (95% CI 45.9 to 62.3; p<0.0001), and the KCCQ overall score was improved by 16.5 points (95% CI 13.9 to 19.1; p<0.0001). The proportion of patients in NYHA class III/IV decreased from 95.0% to 22.9% (p<0.0001). The annualised rate of heart failure hospitalisation was reduced from 3.3 to 0.3 events per patient-year (p<0.0001). LVEF increased by 9.0% (95% CI 6.9% to 11.1%; p<0.0001). The primary safety endpoint, a composite of major adverse cardiac and device-related events at 1 year, occurred in 15.0% of patients, driven primarily by cardiovascular death. CONCLUSIONS: In this prospective cohort study of symptomatic HFrEF patients, treatment with the D-Shant atrial shunt device was associated with significant improvements in functional capacity, quality of life and rates of heart failure hospitalisation at 1 year. The single-arm design precludes definitive conclusions on treatment efficacy, underscoring the need for randomised, sham-controlled trials.