Abstract 2737: 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 phosphodies-terase 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. Optimal medical treatment with ACE-inhibitors and beta-blockers was achieved prior to study initiation. The Minnesota Living with Heart Failure Questionnaire (MLWHFQ) assessed quality of life. Peak oxygen consumption (VO2) and the minute ventilation-carbon dioxide production (VE/VCO2) slope were assessed via cardiopulmonary exercise testing. Parametric statistics compared ratio level data while non-parametric statistics compared ordinal level data.
Results: No adverse effects were reported throughout the study period. Key findings are listed in table⇓. Differences in baseline variables were not significantly different between the two groups. Quality of life and exercise testing variables were significantly improved in the sildenafil group by three months and maintained at six month assessment. Differences in exercise testing variables were not significantly different in the placebo group.
Conclusions: This study provides the first evidence that, in optimally treated stable HF patients, long-term therapy with sildenafil is safe and promotes a significant improvement in gas exchange, exercise performance and quality of life. These findings support further assessment of PDE5 inhibition in the HF population.