Percutaneous endocardial alginate–hydrogel injection in the treatment of heart failure: First‐in‐human study

Abstract Aims Despite the potential of alginate hydrogel intramyocardial injections in the treatment of heart failure (HF), minimally invasive implantation techniques remain scarce. This study evaluated the safety and feasibility of percutaneous transcatheter endocardial alginate hydrogel injection (TEAi), facilitated by novel implants and a dedicated catheter‐based device, in patients with HF with reduced ejection fraction (HFrEF). Methods and Results This first‐in‐human study enrolled HFrEF patients [New York Heart Association (NYHA) Class III–IV and left ventricular ejection fraction (LVEF) ≤35%]. The primary endpoint was the incidence of procedure‐ or device‐related serious adverse events (SADEs) at 30 days. Secondary endpoints included the device success rate, HF hospitalization at 6 months, and change from baseline to 6 months post‐procedure in the following parameters: LVEF as assessed by MRI; NYHA functional class; 6 min walk test distance (6MWT); the quality of life assessed by the Kansas City Cardiomyopathy Heart Failure Questionnaire (KCCQ); and serum N‐terminal prohormone of B‐type natriuretic peptide (NT‐proBNP) level. Pre‐ and post‐procedural biomechanical analysis was also evaluated. Ten patients successfully underwent TEAi with no SADEs at 30 days. There was one death and two HF hospitalizations at 6 months. At 6 months, LVEF improved from 17.7% ± 3.8% to 24.9% ± 11.2% ( P = 0.021), end‐systolic volume decreased from 297.5 ± 67.9 mL to 264.8 ± 101.4 mL ( P = 0.029), and KCCQ scores increased from 49.7 ± 3.9 to 79.0 ± 8.07 ( P = 0.008). No statistically significant changes were observed in end‐diastolic volume, NT‐proBNP and 6MWT at six months compared with the baseline. Biomechanical analysis revealed a reduction in peak left ventricular end‐diastolic wall stress (6.5 ± 1.1 kPa vs. 5.9 ± 1.3 kPa, P = 0.043). Conclusions TEAi is feasible and safe for the treatment of HFrEF, warranting further randomized, efficacy clinical trials.