Rapamycin Treatment in Preclinical Canine Dilated Cardiomyopathy: Results and Insights of The REPAIR Study

Presentation Description / Summary: Dilated cardiomyopathy (DCM) is a primary disease of the myocardium seen in several species, including dogs and humans. It is characterized by progressive ventricular dilation and loss of myocardial contractility. Once DCM progresses to the clinical stage, signs of congestive heart failure are typically seen, with or without cardiac arrhythmias. Rapamycin, also known as sirolimus, is a naturally occurring compound that is a specific inhibitor of the mammalian target of rapamycin (mTOR) cellular pathway. Selective inhibition of mTOR has been shown to provide therapeutic benefit in models of various cardiac disorders, including DCM. Rapamycin treatment has also been shown to reverse age-related declines in cardiac function in both laboratory animals and in client-owned dogs, without significant adverse effects. The REPAIR Study was an open-label longitudinal pilot study to evaluate the efficacy and safety of a novel rapamycin formulation in client-owned dogs with preclinical DCM. Enrolled dogs were monitored throughout a 180-day treatment period. Experimental units consisted of individual dogs, and treatment success was evaluated based on improvements in quality-of-life assessments and echocardiographic measurements. This presentation will discuss the results of The REPAIR Study, including background on the use of rapamycin in veterinary cardiology, specific echocardiographic, Holter, and quality of life results in our multi-center study, pitfalls, case enrollment, and finally future directions for evaluating the use of rapamycin in preclinical canine DCM.