Phosphodiesterase Type 5 Inhibition With Tadalafil Changes Outcomes in Heart Failure

Inclusion Criteria: * Male or female age 21 years or older. * NYHA Class II-IV HF with LVSD (most recent LVEF \< 0.40). * At high risk of future clinical instability, indicated by EITHER: a hospitalization for the primary reason of decompensated HF within the 12 months prior to screening; OR a plasma B-type Natriuretic Peptide (BNP) level ≥ 300 pg/ml or N-terminal prohormone of brain natriuretic peptide (NT-proBNP) ≥1800pg/ml measured during a period of clinical stability in the 3 months prior to screening. * Documented secondary PH within the last 6 months * Medication and device treatment according to current American Heart Association/American College of Cardiology (AHA/ACC) guidelines. * Stable medical therapy for 30 days prior to randomization * African-American patients intolerant of or otherwise unable or unwilling to utilize isosorbide dinitrate/hydralazine therapy will be included. * Willingness to comply with protocol, attend follow-up appointments, complete all study assessments and provide written informed consent. Exclusion Criteria: * Concurrent or anticipated nitrate use for any reason, or nitrate use within the 14 days prior to screening through the day of randomization. * Known allergy, hypersensitivity (anaphylaxis), or adverse reaction to tadalafil or other Phosphodiesterase Type 5 (PDE5) inhibitor * Erectile dysfunction treated with a PDE5 inhibitor. * Severe renal dysfunction defined as an estimated glomerular filtration rate (GFR) \< 30 ml/min/1.73 m\^2 or requiring chronic dialysis * Current use of alpha antagonists (except carvedilol or tamsulosin) or use of cytochrome P450 3A4 inhibitors (ketoconazole, itraconazole, erythromycin, or cimetidine). Patients who have used a protease inhibitor that is a P450 3A4 inhibitor for longer than one week can be enrolled. * Pulmonary arterial hypertension (World Health Organization (WHO) Group I, III-V) for which PDE5 inhibitor therapy may be indicated * Severe pulmonary disease requiring home oxygen therapy * Comorbidities including clinically significant valvular stenosis (aortic valve area \< 0.8 cm\^2 or a mitral valve area \<1.0 cm\^2), uncontrolled hypertension (systolic blood pressure ≥180 mmHg or diastolic blood pressure ≥100 mmHg) or hypotension (systolic blood pressure \<85 mmHg) * Chronic intravenous inotrope therapy * Non-arteritic anterior ischemic optic neuropathy (NAION) * ST elevation MI (STEMI) within 90 days prior to screening * Coronary Artery Bypass Grafting (CABG) or mitral valve surgery, initiation of cardiac resynchronization (CRT) or initiation of β-blocker therapy within the 6 months prior to screening * Infiltrative or inflammatory myocardial disease (e.g. amyloid, sarcoid) * Heart transplant recipient * United Network Organ Sharing (UNOS) status 1A or 1B * Mechanical circulatory support (MCS) use or planned MCS use at time of consent * Active malignancy (except non-melanoma skin cancer) requiring therapy other than observation. * Severe non-cardiac illness resulting in life expectancy judged less than three years * Known chronic hepatic disease defined as aspartate aminotransferase (AST) and alanine transaminase (ALT) levels \> 3.0 times the upper limit of normal * Inability to walk even a few steps due to non-cardiac (e.g. orthopedic) reasons * Participation in any clinical trial within the last 30 days (with exception of observational study) * Previous randomization in PITCH-HF