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 standard
therapy 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; atrial
fibrillation-≥ 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 days
prior to randomization

- Left ventricular ejection fraction (LVEF) of <45% assessed within 12 months prior to
randomization by any method

- If female, is not of reproductive potential or agrees to avoid becoming pregnant while
receiving study drug and for 14 days after the last dose of study drug by complying
with one of the following: practice abstinence from heterosexual activity or use (or
have her partner use) acceptable contraception during heterosexual activity.

Exclusion Criteria:

- Clinically unstable at the time of randomization as defined by either the
administration of any IV treatment within 24 hours prior to randomization, and/or
systolic blood pressure (SBP) <100 mmHg or symptomatic hypotension

- Current or anticipated use of long-acting nitrates or nitric oxide (NO) donors
including isosorbide dinitrate, isosorbide 5-mononitrate, pentaerythritol
tetranitrate, nicorandil or transdermal nitroglycerin (NTG) patch, and molsidomine

- Current or anticipated use of phosphodiesterase type 5 (PDE5) inhibitors such as
vardenafil, tadalafil, and sildenafil

- Current use or anticipated use of a soluble guanylate cyclase (sGC) stimulator such as
riociguat

- Known allergy or sensitivity to any sGC stimulator

- Awaiting heart transplantation (United Network for Organ Sharing Class 1A / 1B or
equivalent), receiving continuous IV infusion of an inotrope, or has/anticipates
receiving an implanted ventricular assist device

- Primary valvular heart disease requiring surgery or intervention, or is within 3
months 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 coronary
revascularization (coronary artery bypass grafting [CABG] or percutaneous coronary
intervention [PCI]) within 60 days, or indication for coronary revascularization at
time 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 another
investigational product ≤30 days prior to randomization or plans to participate in any
other 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 is
involved with this study

- Interstitial Lung Disease

- Is pregnant or breastfeeding or plans to become pregnant or to breastfeed during the
course of the study