Table 1 Eligibility criteria

1. Able to provide written informed consent

1. FEV1 <80% of predicted value or FEV1/FVC <70% on spirometry at screening

2. Men and women ≥18 years old

2. Other valve diseases greater than mild stenosis and/or regurgitation

3. Established clinical diagnosis of chronic systolic heart failure with NYHA class II to IV symptoms currently

3. Neuromuscular, orthopedic, or other noncardiac conditions that prevent completion of a maximal exercise testing

4. Left ventricular ejection fraction ≤40%, as determined by echocardiography at the baseline echocardiographic examination

4. Infiltrative/ inflammatory myocardial or pericardial disease

5. Primary pulmonary arteriopathy

5. Have experienced at least one of the following criteria in the 12 months before study entry:

6. Current use of nitrate preparation therapy (will be deleted) or other PDE5 inhibitors (that is, sildenafil, vardenafil, tadalafil) or cytochrome P450 3A4 inhibitors (ketoconazole, itraconazole, erythromycin)

- Hospitalization for decompensated heart failure

- Acute treatment with intravenous loop diuretics or hemofiltration

7. Severe hypotension (SBP <90 mmHg or DBP <50 mmHg) or uncontrolled hypertension (SBP >180 mmHg or DBP >100 mmHg)

- Pulmonary artery systolic pressure ≥40 mmHg by echocardiography

8. Noncardiac illness with estimated life expectancy <1 year at the time of study entry, based on the judgment of the attending physician

6. Stable medical therapy for 1 month before study entry – no addition or removal or change in major class of medication dosage; that is, renin–angiotensin–aldosterone inhibitors, β-blockers

9. Known severe renal dysfunction (GFR <30 ml/minute/1.73 m² by MDRD equation)

10. Known severe liver disease (ALT or AST level >3 times the upper normal limit, alkaline phosphatase or total bilirubin >2 times the upper normal limit)

11. Actively involved in any physical training program for at least 6 months before study entry

12. Listed for heart transplantation