The PRIME-HF study is a multi-center, patient-level, randomized, open-label study of approximately 450 patients with reduced (left ventricular ejection fraction) LVEF of ≤ 35% and heart-rate ≥70 beats per minute (bpm) who are being discharged from the hospital following stabilization from acute heart failure (HF)(primary or secondary) and will be randomized to a treatment strategy of predischarge initiation of ivabradine or usual care.