Author`s Reply.

To the Editor,

We thank the author(s) for their constructive comments on our study entitled “Heart rate recovery, cardiac rehabilitation, and erectile dysfunction in males with ischemic heart disease” published in the Anatolian Journal of Cardiology 2016; 16: 256-63 (1). In our study, we aimed to assess the relationship between heart rate recovery and the severity of erectile dysfunction (ED) in patients with ischemic heart disease and ED who have undergone cardiac rehabilitation. In addition, we assessed the impact of pharmacotherapy on the severity of ED among others. We are glad to learn that pharmacotherapy of ED and concomitant diseases are interesting because this can improve the overall quality of life in patients with many coexisting disorders.

Indeed nebivolol has unique properties when compared with previous generation beta-blockers. Nebivolol is approximately 3.5 times more cardio selective than bisoprolol, which reduces the risk of side effects typical for other beta-blockers (2). Another advantage of nebivolol is its vasodilator effect due to the increase of endogenous nitric oxide release by the endothelial cells, which leads us to hypothesize about the potentially antiatherogenic effect of this drug and creates the premise that nebivolol could also be beneficial in patients with ischemic heart disease (3); however, at present, it is not approved for the treatment of ischemic heart disease without coexisting arterial hypertension or heart failure (4).

In the erection mechanisms, endothelium-dependent relaxation of the penile arteries is crucial because rapid increase of their capacity up to 80% allows for bringing sufficient volume of blood to initiate the corporal veno-occlusive mechanism and maintain erection (5). The unique effect of nebivolol on the endothelium improves vessel relaxation, and in contrast to other beta-adrenergic blocking agents, nebivolol does not impair sexual function. In males with hypertension and coronary artery disease invasively treated, nebivolol had a protective effect on sexual function (2, 6).

In our study, beta-blockers were taken by 84 (94.38%) patients. Their use had no significant influence on the initial IIEF-5 (EQ1) score, as well as their change (∆ EQ) caused by cardiac training (1). We agree that the comparison of nebivolol with other beta-blockers could bring additional information, but the small percentage of patients on nebivolol vs. bisoprolol, metoprolol, and carvedilol would not guarantee reliable results. At the time of the study, patients used to choose other drugs because of economic reasons. This situation has changed as the introduction of generics improved the availability of nebivolol for more male patients than before and allowed them to benefit from the unique properties of this drug in terms of sexual function.