PDE5A and pulmonary arterial hypertension: The most purchased PAH-specific drug for PAH was PDE5-inhibitor (PDE5i, N = 167 (74 %)), followed by endothelin receptor antagonists (ERA, N = 114 (50 %)); only a small proportion of patients purchased prostacyclin analogues (PCA, N = 17 (7 %) or prostacyclin receptor agonists (PRA, n=<5) 1 year after diagnosis.