Alacepril is an ACE-inhibitor (ACE-I) which has unique properties including excellent vascular wall penetration, peripheral sympathetic nerve suppressive effect, and negative chronotropic effect. It is also suggested to have a superior cough suppressive effect in comparison to other ACE-Is. The purpose of this study was to evaluate whether switching to alacepril from other ACE-Is will alleviate the clinical symptoms of congestive heart failure (CHF) caused by mitral regurgitation (MR) including coughing which could not be adequately controlled by the previously used ACE-I.

Clinical trial involving 73 client-owned dogs with MR that had been treated with ACE-Is other than alacepril was conducted for over a period of one month. Clinical examination was performed before and 4 weeks after the switch to alacepril. General clinical conditions, such as vigor, activeness, appetite and frequency of cough, were scored. Heart rate and body weight were also recorded.

Overall clinical condition suggested an overall symptomatic improvement. Individually, vigor, activeness and frequency of cough showed the greatest improvement with p < 0.0001, whereas appetite showed moderate improvement with p = 0.0055. Body weight and heart rate resulted in significant reduction with p = 0.0073 and p < 0.0001, respectively.

Under the condition of this study, switching to alacepril from other ACE-Is has shown to reduce the heart rate, and also to improve the symptoms of CHF, especially the frequency of cough. Alacepril may be useful in clinical cases of MR with cough that is difficult to control.