The Inorganic Nitrate and eXercise Performance in Heart Failure (iNIX-HF)

Inclusion Criteria To participate in this study, a patient must meet all of the criteria listed below: * Males and females aged greater than or equal to 18y and less than 80y at time of consent * Diagnosis of heart failure with reduced ejection fraction * New York Heart Association (NYHA) Class II-III at Visit 1 * Ejection fraction less than 45%, as evaluated through transthoracic echocardiography at Visit 1 * Stable medical therapy, defined by no addition or removal (or change of more than 100 percent) of the following for 60 days prior to Visit 1: beta-adrenergic blockade and angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blocker (ARB or aldosterone antagonists) or ARNI (ARB + sacubitril) * Ability and willingness to sign an IRB approved written informed consent form; legally authorized representatives are not allowed in this study Exclusion Criteria To participate in this study, a patient must not meet any of the criteria listed below: * Vulnerable populations as defined by the U.S. Department of Health and Human Services; prisoners and children will be excluded from this study * Pharmacologic, organic nitrate therapy within 3 months prior to Visit 1 * Major orthopedic, psychiatric, neurological, or other conditions that would hinder the ability to complete the exercise tests at the time of Visit 1 * Estimated glomerular filtration rate less than 45 mL/min/1.73m2 on screening clinical laboratories measured at Visit 1 * Systolic blood pressure l…