PDE5A and pulmonary arterial hypertension: Since the first description of the favorable effects of PDE5 inhibitors in pulmonary arterial hypertension [7], the positive effects of PDE5 inhibition on cardiac remodeling and secondary pulmonary hypertension have raised the possibility that chronic PDE5 inhibition offers a potential adjunct to the current pharmacological management of chronic SHF [10,22,24].