A Study of Vericiguat in Participants With Heart Failure With Reduced Ejection Fraction (HFrEF) (MK-1242-001)

Inclusion Criteria:

• History of chronic HF (New York Heart Association [NYHA] Class II-IV) on standardtherapy before qualifying HF decompensation
• Previous HF hospitalization within 6 months prior to randomization or intravenous (IV)diuretic treatment for HF (without hospitalization) within 3 months.
• Brain natriuretic peptide (BNP) levels: sinus rhythm-≥ 300 pg/mL; atrialfibrillation-≥ 500 pg/mL and N-terminal pro-Brain Natriuretic Peptide (NT-proBNP)levels: sinus rhythm- ≥ 1000 pg/mL; atrial fibrillation - ≥ 1600 pg/mL within 30 daysprior to randomization
• Left ventricular ejection fraction (LVEF) of <45% assessed within 12 months prior torandomization by any method
• If female, is not of reproductive potential or agrees to avoid becoming pregnant whilereceiving study drug and for 14 days after the last dose of study drug by complyingwith one of the following: practice abstinence from heterosexual activity or use (orhave her partner use) acceptable contraception during heterosexual activity.

Exclusion Criteria:

• Clinically unstable at the time of randomization as defined by either theadministration of any IV treatment within 24 hours prior to randomization, and/orsystolic blood pressure (SBP) <100 mmHg or symptomatic hypotension
• Current or anticipated use of long-acting nitrates or nitric oxide (NO) donorsincluding isosorbide dinitrate, isosorbide 5-mononitrate, pentaerythritoltetranitrate, nicorandil or transdermal nitroglycerin (NTG) patch, and molsidomine
• Current or anticipated use of phosphodiesterase type 5 (PDE5) inhibitors such asvardenafil, tadalafil, and sildenafil
• Current use or anticipated use of a soluble guanylate cyclase (sGC) stimulator such asriociguat
• Known allergy or sensitivity to any sGC stimulator
• Awaiting heart transplantation (United Network for Organ Sharing Class 1A / 1B orequivalent), receiving continuous IV infusion of an inotrope, or has/anticipatesreceiving an implanted ventricular assist device
• Primary valvular heart disease requiring surgery or intervention, or is within 3months after valvular surgery or intervention
• Hypertrophic obstructive cardiomyopathy
• Acute myocarditis, amyloidosis, sarcoidosis, Takotsubo cardiomyopathy
• Post-heart transplant cardiomyopathy
• Tachycardia-induced cardiomyopathy and/or uncontrolled tachyarrhythmia
• Acute coronary syndrome (unstable angina, non-ST elevation myocardial infarction [NSTEMI], or ST elevation myocardial infarction [(STEMI]) or coronaryrevascularization (coronary artery bypass grafting [CABG] or percutaneous coronaryintervention [PCI]) within 60 days, or indication for coronary revascularization attime of randomization
• Symptomatic carotid stenosis, transient ischemic attack (TIA) or stroke within 60 days
• Complex congenital heart disease
• Active endocarditis or constrictive pericarditis
• Estimated glomerular filtration rate (eGFR) <15 mL/min/1.73 m2 or chronic dialysis
• Severe hepatic insufficiency such as with hepatic encephalopathy
• Malignancy or other non-cardiac condition limiting life expectancy to <3 years
• Require continuous home oxygen for severe pulmonary disease
• Current alcohol and/or drug abuse
• Participated in another interventional clinical study and treatment with anotherinvestigational product ≤30 days prior to randomization or plans to participate in anyother trial/investigation during the duration of this study
• Mental or legal incapacitation and is unable to provide informed consent
• Immediate family member (e.g., spouse, parent/legal guardian, sibling or child) who isinvolved with this study
• Interstitial Lung Disease
• Is pregnant or breastfeeding or plans to become pregnant or to breastfeed during thecourse of the study