Effects of Carvedilol Treatment in Dogs with Chronic Mitral Valvular Disease

Background: Stimulation of the sympathetic nervous system occurs during the development of heart failure in dogs with chronic mitral valvular disease (CMVD). Hypothesis: The use of beta-blockers to modulate the activation of the sympathetic nervous system would be useful in dogs with CMVD. Animals: Group A included 13 dogs who received the conventional treatment (digoxin, benazepril, a reduced sodium diet, and codeine, and a diuretic when indicated), and group B included 12 dogs who received the protocol above plus carvedilol (0.3 mg/kg q12h). Methods: Blinded, placebo, controlled study. Results: The main echodopplercardiographic variables, heart rate, biochemical data, functional classification (FC) (New York Heart Association) and quality of life score (functional evaluation of cardiac health questionnaire) were assessed at baseline (TO) and after 3 months (T1). Only group B showed improvement in score of quality of life (13.8 ± 8.8 versus 6.0 ± 6.3; P < .001), in FC (2.4 ± 0.9 versus 1.8 ± 0.7; P = .032) and a reduction in systolic blood pressure (151.2 ± 18.3 versus 124.5 ± 23.4; P = .021). Two deaths from group A and 1 from B were related to CMVD. Conclusion: The studied dose of carvedilol in this group did not improve the sympathetic activation and echocardiographic variables over 3 months of chronic oral treatment. However, the results suggested a beneficial effect on the quality of life score, functional classification, and a reduction on systolic blood pressure.