MYH14 and hydrops fetalis: ATOMIC-HF: Acute Treatment With Omecamtiv Mecarbil to Increase Contractility in Acute Heart Failure; COSMIC-HF: Chronic Oral Study of Myosin Activation to Increase Contractility in Heart Failure; GALACTIC-HF: Global Approach to Lowering Adverse Cardiac Outcomes Through Improving Contractility in Heart Failure; METEORIC-HF: Multicenter Exercise Tolerance Evaluation of Omecamtiv Mecarbil Related to Increased Contractility in Heart Failure; HFrEF: heart failure with reduced ejection fraction; LVEF: left ventricular ejection fraction