A Study Evaluating Biomarkers in Participants With Heart Failure (MK-0000-344)

Inclusion Criteria:

• female of reproductive potential must demonstrate non-pregnant state, and agree to use two acceptable methods of birth control
• postmenopausal or surgically sterile female
• have a Body Mass Index (BMI) >= 18 and =< 35 kg/m^2, inclusive
• healthy participants are in general good health
• participants with HF have no untreated, significant health issue from other co-morbidities, e.g. uncontrolled hypertension
• is willing to undergo echocardiography, CMR, and other study assessments
• participants with HF have a diagnosis of cardiomyopathy, and slight to moderate limitation of physical activity, but are comfortable at rest
• participants with HF are on a stable medical therapy for HF for two weeks prior to start of Part 1
• participants with HF are on a stable diuretic regimen of >= 40 mg/day furosemide or >= 10 mg/day torsemide for at least 2 weeks prior to start of Part 1

Exclusion Criteria:

• has any clinically significant, uncontrolled renal, endocrine (except Type II Diabetes), neurological, hepatic, immunological or inflammatory disease
• has a history of cancer (malignancy)
• had major surgery or donated/lost approximately 500 mL of blood within 4 weeks prior to screening
• participated in another investigational trial within 4 weeks prior to screening
• excepting permitted medications, uses prescription, or non-prescription drugs or herbal remedies 2 weeks prior to enrollment until completion of trial
• takes medications that affect BNP levels within 30 days prior to screening
• undergoes high-intensity physical exercise from 1 week prior to pretrial visit until completion of trial
• has implanted or embedded metal objects in body that in response to a magnetic field could cause injury
• suffers from claustrophobia making them unable to undergo CMR scanning
• consumes alcohol for 7 days prior to screening until completion of study
• consumes excessive amounts of caffeinated beverages
• uses cannabis regularly, or any illicit drugs, or has a history of drug (including alcohol) abuse within prior 12 months