A Study of Ivabradine in African-American/ Black Subjects With Heart Failure and Left Ventricular Systolic Dysfunction.

Inclusion Criteria: * Subject has provided informed consent/assent prior to initiation of any study specific activities/ procedures * Male or female subject ≥ 18 years of age, describing self as African American/Black * Must have a diagnosis of heart failure (HF) confirmed by medical records, be in stable condition, and treated with stable optimal pharmacological therapy as per their personal physician's care. * Left ventricular ejection fraction (LVEF) ≤ 35% confirmed by investigator * New York Heart Association (NYHA) class II to IV assessed at the time of screening * Electrocardiogram (ECG) documentation at the time of screening of sinus rhythm with resting heart rate (HR) ≥ 70 bpm by local ECG reading * Must be able to complete a 6-minute walk test (6MWT) and wear an accelerometer Exclusion Criteria: * Recent myocardial infarction (≤ 2 months) or stroke (≤ 1 month) prior to enrollment * If the subject received within 3 months before or is scheduled to receive within 42 days after enrollment any of the following: revascularization, ventricular assist device, continuous or intermittent inotropic therapy, hospice care, major organ transplant, or is receiving renal replacement therapy by dialysis * If the subject received implantation of a cardioverter defibrillator or cardiac resynchronization therapy within 42 days before or is scheduled to receive implantation of a cardioverter defibrillator or cardiac resynchronization therapy within 42 days after enrollment * Severe p…