Exercise Capacity Study of LCZ696 vs. Enalapril in Patients With Chronic Heart Failure and Reduced Ejection Fraction.

Inclusion Criteria: * Patients with a diagnosis of chronic heart failure (NYHA class III) and reduced ejection fraction (LVEF ≤ 40%) * Reduced ability to exercise, evidenced by VO2peak ≤ 18 ml/min per kg * Patients had to be on an ACEI or an ARB at a stable dose of at least enalapril 10 mg/d or equivalent for at least 4 weeks prior to the screening visit and until randomization visit. Exclusion Criteria: * History of hypersensitivity or allergy to any of the study drugs, drugs of similar chemical classes, ACEIs, ARBs, or NEP inhibitors as well as known or suspected contraindications to the study drugs * Previous history of intolerance to recommended target doses of ACEIs or ARBs * Known history of angioedema * Requirement of treatment with both ACEIs and ARBs * Current acute decompensated HF (exacerbation of chronic HF manifested by signs and symptoms that may require intravenous therapy) * Symptomatic hypotension * Impaired renal function * Pregnant or nursing (lactating) women