An international clinical trial involving the drug pimobendan showed such positive results in canine heart patients that the researchers ended their work early, Texas A&M University reported Tuesday. The full study, which is sponsored by Boehringer Ingelheim Vetmedica, the maker of Vetmedin (pimobendan) chewable tablets, is expected to be published later. The research team, which included Texas A&M associate professor Sonya Gordon, DVM, Dipl. ACVIM, conducted what the university called the largest clinical study ever involving dogs suffering from myxomatous mitral valve disease (MMVD). A group of 360 canine patients was randomly split between those given pimobendan or a placebo in a double-blind study. Sixteen of the dogs were managed at Texas A&M, while the others were seen at 35 other trial centers in the United States and abroad. Pimobendan was found to delay the onset of clinical signs of congestive heart failure in dogs with increased heart size secondary to preclinical MMVD. “A midstudy analysis in mid-February 2015 indicated that pimobendan is clearly beneficial and did not raise any concern over the administration of pimobendan,” Texas A&M stated. “Based on these results the interim analysis committee recommended that the study be stopped and the lead investigators … ended the study March 1.” Besides Dr. Gordon, the lead investigators included Adrian Boswood, VetMB, MRCVS, of the Royal Veterinary College in England and Jens Häggström, DVM, Ph.D., Dipl. ECVIM, of the Swedish University of Agricultural Sciences. MMVD is the leading cause of heart disease and heart failure in dogs, according to Texas A&M. “The results of this clinical trial have the potential to change the way the most common cause of heart disease and heart failure in the dog is managed on a day-to-day basis by veterinarians around the world,” Gordon said. Vetmedin (pimobendan) is currently indicated for the management of signs of congestive heart failure in dogs due to atrioventricular valvular insufficiency (AVVI) or dilated cardiomyopathy (DCM). The drug should not be given in cases of hypertrophic cardiomyopathy or aortic stenosis, Boehringer Ingelheim noted.
