Sildenafil in US Heart Failure Patients (SilHF-US) (SilHF-US Trial)

This protocol describes a 2-arm randomized controlled pilot study assessing the tolerance, safety and efficacy of sildenafil compared to control. The hypothesis is that sildenafil will be well tolerated and efficacious in patients with chronic heart failure (NYHA class II and III) with evidence of systolic dysfunction (EF ≤40 %) and secondary pulmonary hypertension (SPAP \>40mmHg). Patients that satisfy the inclusion criteria will be randomized to sildenafil (40mg x 3) or placebo therapy for 6 months in a 2:1 blinded fashion. The placebo group will be compared to the active therapy group and analyzed for differences in the main study end-points Patient Global Assessment and 6-Minute Walk Test. The study will also assess safety, tolerability, symptoms and quality of life.