A Study of Vericiguat (MK-1242) in Participants With Chronic Heart Failure With Reduced Ejection Fraction (HFrEF) (MK-1242-035)

Inclusion Criteria: * History of chronic HF \[New York Heart Association (NYHA) Class II to IV\] on guideline-directed medical therapy for heart failure (GDMT) with no HF hospitalization within 6 months or outpatient IV diuretic use within 3 months before randomization. * Left ventricular ejection fraction (LVEF) of ≤40%, assessed within 12 months before randomization by any imaging method. * Elevated N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. * A female participant is eligible to participate if she is not pregnant or breastfeeding, is not a woman of childbearing potential (WOCBP), or is a WOCBP and agrees to follow contraceptive guidance during the study intervention period and for at least 1 month after the last dose of study intervention. Exclusion Criteria: * Has SBP \<100 mm Hg or symptomatic hypotension. * Awaiting heart transplantation, is receiving continuous IV infusion of an inotrope, or has or anticipates receiving an implanted ventricular assist device. * Amyloidosis or sarcoidosis. * Primary valvular heart disease requiring surgical procedure or intervention or has undergone a valvular surgical procedure or intervention within 3 months before randomization. * Hypertrophic cardiomyopathy. * Acute myocarditis or Takotsubo cardiomyopathy. * History of heart transplant. * Tachycardia-induced cardiomyopathy and/or uncontrolled tachyarrhythmia. * Acute coronary syndrome, or undergone coronary artery bypass grafting (CABG) or percutaneous coronary i…