[Cardio-vascular effects of sildenafil: new data].

Sildenafil is an inhibitor of phosphodiesterase 5, which has important vasodilatory properties. Though sildenafil provokes a decrease in systemic arterial pressure, its safety has been confirmed in large series of patients on several kinds of anti-hypertensive therapy. Likewise, post-marketing surveys, in the US or United Kingdom, have recorded a number of cardio-vascular deaths following sildenafil administration which was lower than expected, provided the contra-indication with the concomitant use of nitrates is observed. In patients with known or suspected coronary artery disease, sildenafil does not modify the tolerance or results of echocardiographic exercise testing. However, sildenafil does increase coronary flow reserve, both in narrowed or normal coronary arteries, with no sign of a "steal" phenomenon. Because of its capacity to retard the degradation of cGMP, by the inhibition of phosphodiesterase 5, the effect of sildenafil in primary pulmonary hypertension has been evaluated in several studies: acutely, sildenafil decreases pulmonary artery pressure, either alone or in combination with inhaled iloprost or NO. On the same line, sildenafil decreases hypoxia-induced pulmonary hypertension in normal volunteers. These findings, together with reports of long-term improvement in symptoms and levels of pulmonary artery pressure in patients with primary pulmonary hypertension, will warrant further trials to document its potential role in this otherwise severe disease.