Study to Evaluate the Safety and Tolerability of AMG 986 in Healthy Volunteers and Heart Failure Patients

This study is a randomized, placebo-controlled, double-blind, single day ascending dose (SDAD) study (Part A), a multiple daily ascending dose (MDAD) study (Part B), in healthy adults, and a MDAD study (Part C) in heart failure patients. In Parts A and B of the study, healthy volunteers will receive AMG 986 by continuous IV infusion or by oral administration in a fasted state. IV Infusions will be divided into an initial loading dose (LD) for the first hour followed immediately by a maintenance dose (MD). In Part C of the study, patients with heart failure and either reduced (HFrEF) or preserved (HFpEF) ejection fraction will receive MDAD of AMG 986 or matching placebo once daily by oral administration for 21 days.