Short Term Echocardiographic and Clinical Effects of Ramipril on Dogs with Asymptomatic Degenerative Mitral Valve Disease

Angiotensin converting enzyme (ACE) inhibitors have beneficial effects on degenerative mitral valve disease (DMVD) dogs with stages C and D (ACVIM classification) and on dogs with congestive heart failure. However, ACE inhibitors’ effects on stage B2 or asymptomatic DMVD dogs have still been uncertain. Ramipril is an ACE inhibitor that has lipophilic effects and can suppress ACE in cardiac tissue effectively. We hypothesized that ramipril had beneficial effects on dogs with naturally occurring DMVD in stage B2. Twenty dogs with stage B2 DMVD, weighing between 3-12 kg and being older than 6 years, were recruited into the study. The dogs were single blinded randomized and divided into 2 groups. Owners made decisions whether or not to supplement their dogs with ramipril. Dogs in the ramipril group (n = 10) received ramipril once a day at dose of 0.22 mg/kg PO. The control group (n = 10) did not receive any drugs for 91 days. Complete physical examination, electrocardiography and echocardiography were performed on days 0, 28, 56 and 91. Echocardiographic examination was used to determine cardiac sizes and structural changes. Independent t-test was performed to compare differences between dogs in ramipril and control groups. Repeated ANOVA was used to compare differences within groups between days 0, 28, 56 and 91. P < 0.05 was considered statistically significant. Cardiac chamber size, systolic function and severity of mitral regurgitation were not significantly different between the 2 groups throughout the study period. In conclusion, ramipril did not affect cardiac size, severity of mitral regurgitation and systolic function in 91-day study period.