01898-A: Enhancing Diagnosis and Treatment of Cardiomyopathy through Identification of Biological Markers of Disease

Project Summary

The development of blood-based cardiac biomarkers such as NT-proBNP has revolutionized the way in which we screen for certain types of heart disease. These markers may also aid in our understanding of the underlying causes of cardiac disease and improve our ability to offer prognostic and therapeutic recommendations for affected animals. NT-proBNP has been shown to be an effective tool in screening for Dobermans with dilated cardiomyopathy, and has been shown to predict the onset of heart failure in dogs with chronic mitral valvular disease. Elevated markers of inflammation have also been identified in the bloodstream of people with arrhythmogenic right ventricular cardiomyopathy (ARVC), implicating a possible role of systemic inflammation in the progression of the disease.

The purpose of this study was to measure NT-proBNP and various biomarkers of inflammation in the bloodstream of Boxers with ARVC and to correlate the levels of these markers with severity of arrhythmia on Holter monitor, striatin status, and various echocardiographic measurements. We hypothesized that Boxers with cardiomyopathy would have increased levels of NT-proBNP and inflammatory markers compared to healthy Boxers; and that these changes would be more profound in dogs with cardiac dilation. At this point in time we have completed enrollment and sample collection for the study and have enrolled 12 normal Boxers, 15 Boxers with arrhythmia and a normal echocardiogram, and 11 Boxers with echocardiographic evidence of cardiac dilation. The results of inflammatory marker analysis are still pending, however initial results indicate that NT-proBNP may be a reliable indicator of Boxers with cardiac dilation. If this is the case, then this non-invasive blood-based marker of cardiac function might replace the need for serial screening echocardiograms in asymptomatic Boxers. This could also allow for more widespread screening efforts of Boxers at dog shows and clinics without a cardiologist, and may improve our ability to offer a prognosis for individual dogs. The increased availability and affordability of screening efforts involving NT-proBNP measurement may allow us to more readily identify dogs at an earlier stage of cardiac dilation, allowing for these animals to be started on cardiac medications sooner and also to better inform breeding decisions. The results of this study are anticipated to improve our understanding of cardiomyopathy in the Boxer, and to open exciting new avenues for screening and possible treatment of affected dogs.

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