Efficacy of sildenafil as a rescue therapy for patients with severe pulmonary arterial hypertension and given long-term treatment with prostanoids: 2-year experience

Background: Both prostanoids and sildenatil are effective treatments for severe pulmonary arterial hypertension (PAH). The combined use of these drugs to maximize the clinical benefit is an emerging treatment option. This study describes a 2-year experience with adjunct sildenafil as a rescue therapy for patients with severe PAH treated long term with prostanoids and who showed clinical deterioration or onset of heart failure. Methods: Twenty patients (11 men, 9 women; mean age 42 +/- 11 years) with severe PAH, who showed clinical or functional worsening despite ongoing treatment with prostanoids (8 subcutaneous, 7 intravenous, 5 inhaled), were started on adjunct oral sildenafil. New York Heart Association (NYHA) functional class, 6-minute walking test, signs of right ventricular failure and echocardiography were assessed before and after 1 and 2 years of combined therapy. Results: There was a significant improvement of NYfIA functional class and signs of right heart failure after 1- and 2-year follow-up. Patients showed a mean increase in 6-minute walking distance of 79 m and 105 m after 1 and 2 years of adjunct sildenafil, respectively. Two patients died during follow-up. The echocardiographic parameters showed a significant reduction of right ventricular end-diastolic diameter and left ventricular diastolic eccentricity index. No serious side effects related to sildenafil were observed. Conclusions: Adjunct sildenafil to long-term prostacyclin therapy in patients with severe PAH provided sustained clinical stabilization and an improved clinical situation, exercise capacity and echocardiographic parameters of right ventricular function. The beneficial effects were strong and lasted > 24 months.