Background: Studies have demonstrated that phosphodiesterase 5 (PDE5) inhibition is associated with right ventricle (RV) functional improvement in patients with primary pulmonary hypertension. This study aims to demonstrate the immediate impact of Sildenafil, a PDE5 inhibitor, on RV function, measured by cardiovascular magnetic resonance (CMR), in patients with heart failure (HF).
Methods: We conducted a randomized double-blind controlled trial.
Inclusion criteria: diagnosis of HF functional class I-III; left ventricle ejection fraction < 35%. Patients underwent CMR evaluation and were then equally randomly assigned to either 50 mg of Sildenafil or Placebo groups. One hour following drug administration, they were submitted to a second scan examination.
Results: 26 patients were recruited from a tertiary reference center in Brazil and 13 were allocated to each study group. The median age was 61.5 years (50-66.5 years). Except for the increase in RV fractional area change following the administration of sildenafil (Sildenafil [before vs. after]: 34.3 [25.2-43.6]% vs. 42.9 [28.5-46.7]%, p = 0.04; Placebo [before vs. after]: 28.1 [9.2-34.8]% vs. 29.2 [22.5-38.8]%, p = 0.86), there was no statistically significant change in parameters. There was no improvement in left ventricular parameters or in the fractional area change of the pulmonary artery.
Conclusion: This study demonstrated that a single dose of Sildenafil did not significantly improve RV function as measured by the CMR.
Trial registration: ClinicalTrials.gov NCT01936350.