Sildenafil in Patients with Severe Group 3 Pulmonary Hypertension

Background: Patients with pulmonary hypertension (PH) in respiratory disease (group 3 PH) have adverse outcomes. Some studies suggest that patients with more severe PH (mPAP≥35mmHg) benefit from sildenafil use. Aims: To assess short term outcomes following sildenafil use in patients with severe group 3 PH. Methods: Patients from the Royal Brompton Hospital were assessed at baseline and 3-6 month follow-up using right heart catheterisation (RHC), echocardiography, brain natriuretic peptide (BNP), 6-minute walk test (6MW) and a PH-specific quality of life score (EmPHasis-10, E10). Other contributing factors to PH were excluded. Sildenafil was initiated at 12.5-25mg TDS. Data are mean±SD or median (IQR). Results: Patients (n=18) were 50% male, 63.5±11.3 years with ILD (n=8), combined pulmonary fibrosis and emphysema (n=3), COPD (n=4) and sleep disorders (n=3), had FEV1 64.3±30.9%, FVC 73.8±33.4%, FEV/FVC 71.7±16.9%, TLCO 22.4±6.4% and KCO 47.5±33.8% predicted. RHC showed mPAP 47.4±11.0mmHg, PCWP 9±4mmHg and PVR 10.7±5.1 Wood units. 3/18 did not tolerate sildenafil (hypotension, no benefit, unmasking of diastolic dysfunction). At 3-6 months, BNP fell from 699±646 to 451±450, p=0.02, E10 improved from 37±10 to 29±12, p=0.002. WHO functional class improved, p=0.054 (Figure A-D). Conclusion: Sildenafil was well tolerated in patients with severe group 3 PH, with improved WHO FC, BNP and quality of life, and a good safety signal. Larger studies are warranted.