Carvedilol in dogs with dilated cardiomyopathy.
BACKGROUND
Dilated cardiomyopathy (DCM) is characterized by reduced systolic function, heightened sympathetic tone, and high morbidity and mortality. Little is known regarding the safety and efficacy of beta-blocker treatment in dogs with DCM.


OBJECTIVE
Carvedilol improves echocardiographic and neurohormonal variables in dogs with DCM over a 4-month treatment period.


METHODS
Prospective, placebo-controlled, double-blinded randomized study. Dogs with DCM underwent echocardiography, ECG, thoracic radiographs, and neurohormonal profiling, followed by titration onto carvedilol (0.3 mg/kg q12h) or placebo over a 4-week period and subsequently received 3 months of therapy. Primary study endpoints included left ventricular volume and function.


RESULTS
Sixteen dogs received carvedilol and 7 received placebo. At study end, 13 carvedilol dogs and 5 placebo dogs were alive. There was no difference in the mean percentage change in left ventricular volume at end-diastole (LVVd), left ventricular end-systolic volume (LVVs), and ejection fraction (EF) between treatment groups, suggesting that both groups experienced similar amounts of disease progression. Carvedilol treatment did not result in significant changes in neurohormonal activation, radiographic heart size, heart rate, or owner perceived quality-of-life. Baseline B-type natriuretic peptide (BNP) predicted dogs in the carvedilol-treated group that maintained or improved their EF over the study duration.


CONCLUSIONS
Carvedilol administration did not improve echocardiographic or neurohormonal indicators of heart function. The lack of effect may be related to severity of disease, carvedilol dose, or brevity of follow-up time. Statistical power of the present study was adversely affected by a high fatality rate in study dogs and small sample size.
Oyama
Mark A
MA
Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL, USA. maoyama@vet.upenn.edu
Sisson
D David
DD
Prosek
Robert
R
Bulmer
Barret J
BJ
Luethy
Mike W
MW
Fuentes
Virginia Luis
VL
D000818:Animals; D002227:Carbazoles / Q000627:therapeutic use*; D002311:Cardiomyopathy, Dilated / Q000188:drug therapy / Q000662:veterinary*; D000077261:Carvedilol; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D011412:Propanolamines / Q000627:therapeutic use*; D014665:Vasodilator Agents / Q000627:therapeutic use*
D002227:Carbazoles; D011412:Propanolamines; D014665:Vasodilator Agents; D000077261:Carvedilol