Background: Sildenafil inhibits phosphodiesterase-5, enhancing cyclic guanosine monophosphate- mediated relaxation of pulmonary vasculature and is effective in treating patients with pulmonary arterial hypertension (PAH).
Methods: Patients with PAH (n = 278) received oral sildenafil (20, 40, or 80 mg three times daily) in a 12-week, double-blind, placebo-controlled study and an open-label extension. Health-related quality of life (HRQoL) was recorded by patients using the Medical Outcomes Study 36-item short form (SF-36) and EuroQol 5D (EQ-5D) questionnaires at baseline and after 12 and 24 weeks of therapy. Data are presented for patients who received sildenafil for up to 24 weeks.
Results: Sildenafil-treated patients, compared with placebo-treated patients, exhibited significant improvement in exercise capacity at week 12 (p < 0.001). Increases from baseline to week 12 were observed in all SF-36 domains for sildenafil-treated patients, with statistically significant improvements, compared with placebo-treated control subjects, in physical functioning (p < 0.001), general health (p < 0.001), and vitality (p < 0.05). Statistically significant improvements were also observed for the EQ-5D current health status (p < 0.01) and utility index (p < 0.01). These benefits were maintained for 24 weeks. Treatment groups were pooled for analyses as the results for the 6-min walk distance, SF-36, and EQ-5D were not dose dependent.
Conclusions: Sildenafil improves HRQoL of PAH patients. These improvements appear to be maintained for at least 24 weeks. The effects are strongest in domains addressing the physical impact of health on daily activities and patients’ overall perception of health.