PDE5A and pulmonary arterial hypertension: Current PAH-targeted agents (phosphodiesterase type-5 (PDE-5) inhibitors, endothelin receptor antagonists, guanylate cyclase stimulators, prostacyclin analogues, and prostacyclin receptor agonists), either by monotherapy or combination therapies, can partially improve patients’ symptoms and haemodynamics by dilating pulmonary vessels.