Long-term effect of inhibition of the angiotensin-converting enzyme (ACE) on cavernosal perfusion in men with atherosclerotic erectile dysfunction: a pilot study.

Introduction: Impaired perfusion of the corpora cavernosa is considered an important causal factor of erectile dysfunction (ED) in the aging male with atherosclerosis. Aim. On the basis of this notion, we hypothesized that inhibition of angiotensin-converting enzyme (ACE) may have a structural beneficial effect on cavernosal perfusion and subsequently on erectile function in men with impaired cavernosal perfusion.

Methods: A total of 59 men with atherosclerotic ED (mean age, 60.0 +/- 6.8 years) and impaired cavernosal perfusion, as demonstrated with penile-pharmaco duplex ultrasonography, were randomized between an ACE inhibitor and placebo treatment arm. The minimum period of intervention was 26 weeks (26-46 weeks). The goal of the study was to demonstrate an improvement of (i) cavernosal arterial perfusion demonstrated by a decrease of blood flow velocity waveform; and (ii) erectile function in the erection domain of the International Index of Erectile Function.

Results: Cavernosal perfusion improved significantly (paired samples t-test, P < 0.05) in both study arms, but the improvement did not differ significantly (anova, P > 0.05) between both arms. The number of sexually active men increased, and the severity of ED decreased in both groups.

Conclusion: Although a persisting improvement of cavernosal perfusion by at least a 6 month-administration of an ACE inhibitor in men with advanced atherosclerotic ED could not be demonstrated in this pilot study, the beneficial effect on cavernosal perfusion, sexual activity, and erectile function in all participants of this study is remarkable. This pilot study warrants a follow-up study in sexually more active men with ED and less advanced atherosclerosis to show that ACE inhibition may result in persisting improvement of cavernosal perfusion.