Inclusion Criteria:  Positive serology for Chagas; Age > 18 years old; New York Heart Association (NYHA) heart failure and functional class II, III or IV; Left ventricular ejection fraction <40% at least in the last 3 months; Patients using a beta-blocker with stable dose (last 4 weeks) and optimized; Patients using ACEI or ARB with a stable dose (last 4 weeks) and optimized.  Exclusion Criteria:  Participants who do not agree to participate in the study Participants who do not want to receive sacubitril/ valsartan medication; Patients with symptomatic hypotension; Patients with systolic blood pressure (SBP) lower than 95 mmHg on randomization; Patients with creatinine clearance (ClCr) less than 30 mL/min; Patients with serum potassium > 5.2 mmol/L; Patients with a history of angioedema or who experienced severe side effects with ACE inhibitors.