PDE5A and Right ventricular hypertrophy: In PH, where endothelial PDE5 is expressed more abundantly than in healthylung,29,60 the vasodilatory effects of PDE5i (leading to reductions inpulmonary arterial pressure) are well-described.27,61, , –64 Furthermore, PDE5iattenuate vascular remodelling and right ventricular hypertrophy, as well asimproving functional status in PH.29,60,65,66