Effect of Angiotensin Receptor/Neprilysin Inhibitors on Transthyretin Cardiac Amyloidosis and Heart Failure with Reduced Ejection Fraction

Transthyretin cardiac amyloidosis (ATTR) has emerged as a prevalent and underdiagnosed cause of heart failure (HF), affecting patients both with preserved left ventricular ejection fraction (LVEF) and with systolic dysfunction. It remains unclear whether this population benefits from standard treatments for HF with reduced LVEF or whether treatment with renin-angiotensin system inhibitors and neprilysin might even be harmful in ATTR. The investigators plan to conduct a prospective, randomized, multicenter, open-label clinical trial to evaluate the safety and efficacy of Sacubitril/Valsartan (Sac/Vals), as recommended in current HF guidelines, versus no treatment in patients with ATTR and heart failure with reduced ejection fraction (HFrEF), including those with LVEF ≤40%. Approximately 114 patients from four Spanish centers will be randomized 1:1 to receive Sac/Vals treatment (up to the maximum tolerated dose) or to not initiate the drug, with stratification by center and tafamidis treatment. It has been included a run-in period with a low dose of Sac/Vals to assess tolerance prior to randomization. Patients will have scheduled follow-up visits at 3, 6, and 12 months, during which clinical, functional, analytical, electrocardiographic, and echocardiographic variables will be evaluated. The primary objective is to determine the impact of Sac/Vals treatment on systolic function in patients with ATTR and HFrEF by assessing the change in LVEF on echocardiogram at 12 months. Improvement in LVEF will be defined as an increase of ≥5% from the baseline echocardiogram to the 12-month follow-up.