Impact of first-line sildenafil monotreatment for pulmonary arterial hypertension

Background: Sildenafil has been demonstrated as effective for the treatment of pulmonary arterial hypertension (PAH). The purpose of this study was to investigate the occurrence of clinical events after sildenafil monotreatment as a first-line therapy in patients with PAH over a long-term observation period. Methods and Results: Sildenafil was administered as a first-line drug to 46 patients with PAH (including 24 patients with idiopathic PAH) during 2003-2010. We investigated subsequent clinical events such as the addition of epoprostenol, hospitalization for right-side heart failure, and death. All the hemodynamic parameters and the 6-min walk distance improved significantly in the enrolled patients as a whole receiving sildenafil treatment; 15 (33%) of the 46 patients required the addition of epoprostenol during follow-up. Kaplan-Meier analysis demonstrated that more than 60% of the patients receiving first-line sildenafil treatment did not require the addition of epoprostenol for a 5-year period. Furthermore, the 5-year survival rate after first-line sildenafil treatment was 81%. Finally, more than 75% of the enrolled patients did not reach the composite endpoint of hospitalization for right-side heart failure and death for a 5-year period. Conclusions: This study describes the long-term outcome of patients with PAH receiving sildenafil monotreatment as a first-line therapy and suggests that it is a promising therapeutic strategy.