Chronic sildenafil therapy improves quality of life, exercise oxygen uptake and ventilation efficiency in stable heart failure patients

Background: We previously demonstrated that NO pathway overexpression by phosphodiesterase 5 (PDE5) inhibition with sildenafil acutely improves gas exchange and exercise performance in heart failure patients (HF). This study assesses the impact of chronic sildenafil therapy on gas exchange, exercise performance and quality of life in patients with stable HF. Methods: According to a double-blind, placebo-controlled design, 22 stable HF patients (NYHA Class II-III) with systolic dysfunction (average left ventricular ejection fraction: 36 ± 4 %) were randomly assigned (1:1) to receive placebo or sildenafil (25 mg, 3 times/day) for six months.