The ALT FLOW early feasibility study 3-year results assessing left atrial to coronary sinus shunting in HFpEF

Left atrial-to-coronary sinus (LA-to-CS) shunting through the APTURE transcatheter shunt system aims to unload the LA while preserving the interatrial septum. This article aims to examine the 3-year health status, functional capacity, and clinical outcomes of the ALT-FLOW Early Feasibility Study (EFS).

Device safety, patency, and echocardiographic parameters, but also symptoms, health status, and exercise capacity were assessed in patients with left ventricular ejection fraction (LVEF) > 40% (n & 95). Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) score predicted 3-year all-cause mortality was compared with observed mortality assessed by Kaplan-Meier analysis using adjudicated events. Predicted and observed HF hospitalization (HFH)-free survival rates were also compared.

At 3 years, the safety profile remained stable with no new safety signals, and all implanted shunts remained patent. 76.3% of patients improved by at least one NYHA class, and mean KCCQ Overall Summary Scores increased by 25 points from baseline (P < .0001). The 6-min walk distance improved by an average of 39 m (P & .002). These benefits were consistent regardless of baseline pulmonary vascular resistance (PVR). Right heart echocardiographic parameters after 3 years were stable, though a reduction in TAPSE was observed, primarily in the high PVR subgroup. The observed 3-year survival was significantly higher than the MAGGIC-predicted survival (84.4% vs 70.2, respectively; P & .009), as well as the HFH-free survival (68.0% vs 24.0%, respectively; P < 0001).

In patients with HF and LVEF >40%, the APTURE LA-to-CS shunting confirmed an acceptable safety profile with stable right heart parameters and sustained improvements in symptoms, quality of life, and functional capacity at 3 years. Observed survival and HFH were superior to MAGGIC predictions.