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:
  1. a hospitalization for the primary reason of decompensated HF within the 12 months prior to screening; OR
  2. 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