[Two-year follow-up of pulmonary arterial hypertension patients treated with sildenafil].

Background: The long-term effects of drugs developed for the control of pulmonary arterial hypertension (PAH) are little known, since multicenter studies usually last 12 to 16 weeks.

Objective: To evaluate the two-year outcome of PAH patients receiving monotherapy with sildenafil (a phosphodiesterase-5 inhibitor), with regard to their functional capacity.

Methods: Twenty four patients (ages between 8 and 54 years) with idiopathic PAH (IPAH, n = 9) or congenital heart disease-associated PAH (CHD-PAH, n = 15) were treated with sildenafil for two years, with daily oral doses ranging from 60 to 225 mg (tid). Physical capacity was assessed by the distance walked in the 6-minute walk test (DW6M) and by the degree of dyspnea at the end of the walk (Borg scale); peripheral oxygen saturation was also recorded (SpO(2)6M, pulse oximetry).

Results: In the 18 patients who completed the two-year follow-up, there was a progressive and sustained increase in DW6M, both in the IPAH group (from 239 +/- 160 m to 471 +/- 66 m, p = 0.0076) and in the CHD-PAH group (from 361 +/- 144 m to 445 +/- 96 m, p = 0.0031), with improvement of dyspnea at the end of the walk (p<0.05 for both groups). No decrease in SpO(2)6M was observed in the groups; in patients with CHD-PAH, in particular, SpO(2)6M went from 77 +/- 20% to 79 +/- 16% (p = 0.5248). Five deaths occurred (three in the IPAH group) and one patient was lost to follow-up during the study period.

Conclusion: In a two-year follow-up, sildenafil proved useful in the control of the functional status of PAH patients, with significant improvement in both groups considered.