Hemodynamic and Exercise Effects of Phosphodiesterase 5 Inhibitors

Phosphodiesterase 5 (PDE5) inhibitors have modest nitrate-like hemodynamic effects, lowering wedge pressure, pulmonary artery pressure, and systolic and diastolic arterial pressure. At rest, decreases in arterial pressure averaging 9/8 mm Hg may increase to 12/5 mm Hg as a result of the vasodilatory response, but no clinical adverse effects have been reported. On the background of increased vasoconstriction related to elevation of angiotensin II, a greater decrease may occur and be relevant to cardiovascular therapy, particularly if angiotensin II antagonists are coprescribed. Exercise studies in patients with ischemia identified no adverse event potential for sildenafil, vardenafil, and tadalafil. Another study showed sildenafil had an anti-ischemic effect, increasing time to limiting angina. Evidence supports the safety of these agents in patients with chronic stable coronary artery disease (CAD). With accumulating evidence of benefits on endothelial function and clinical improvements in pulmonary hypertension and heart failure, the hemodynamic and exercise effects of PDE5 inhibitors suggest an important therapeutic cardiovascular role, reinforcing their safety in the patient with CAD and erectile dysfunction.