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

Inclusion Criteria: * Patients ≥ 18 years of age of both sexes. * Patients diagnosed with ATTR cardiac amyloidosis as indicated in guidelines, both in its hereditary form (ATTRv) or wild-type form (ATTRwt). * Patients initially evaluated or under follow-up in Cardiomyopathy/Heart Failure/Amyloidosis Units at participating centers. * Heart failure and reduced ejection fraction: LVEF ≤40%, in functional class I, II, or III according to the New York Heart Association (NYHA). Exclusion Criteria: * NYHA Functional Class IV. * Stage 4 and 5 chronic kidney disease (creatinine clearance by CKD-EPI \<30 mL/min/1.73m²). * Hyperkalemia (blood potassium levels \> 5.4 mmol/L). * Hypotension defined as systolic blood pressure (SBP) \<100 mmHg on two consecutive measurements. * Treatment with ACE inhibitors, ARBs, or sacubitril/valsartan at the time of enrollment. * History of angioedema or hypersensitivity to ACE inhibitors or ARBs. * Treatment with TTR gene silencers or diflunisal. * Participation in another clinical trial. * Pregnancy, breastfeeding, or fertile women unwilling to use adequate contraception throughout the study duration. * Any condition that, in the investigator's opinion, compromises participation in the study.