CLINICAL VALUE OF CARDIAC TROPONIN I (CTNI), CARDIAC TROPONIN T (CTNT), SERUM B‐TYPE NATRIURETIC PEPTIED (BNP) AND PRO‐BNP IN DOGS WITH CLASS IV CONGESTIVE HEART FAILURE DUE TO MITRAL REGURGITATION

Abstract

Introduction: Mitral valve disease (MVD) is the most common acquired heart disease in dogs. When it results in congestive heart failure (CHF), MVD becomes an important cause of morbidity and mortality in dogs. Markers for determining the severity of cardiac injury and the heart's response to therapy might provide valuable information regarding the overall prognosis early in the course of CHF. This information might also provide a means for identifying those dogs with MVD that are at risk for CHF and those that might benefit from specific therapeutic interventions. In this study, we propose to investigate markers of cardiac myocyte injury in dogs that present in advanced (or Class IV) CHF due to MVD. Cardiac troponin I (CTnI) and cardiac troponin T (CTnT) are markers specific for cardiac myocyte damage, and serum B‐type natriuretic peptide (BNP and pro‐BNP), for myocyte stretch. These markers have shown predictive value in human and veterinary medicine, however further investigation is required. It is our hypothesis that one or more of these markers will be elevated at presentation compared to established laboratory normal values.Methods: Fifteen dogs that presented with Class IV CHF due to MVD based on physical examination findings, thoracic radiographs, and cardiac ultrasound had a blood sample drawn to measure serum levels of CTnT, CTnI and BNP, and pro‐BNP at a commercial laboratory using immunoassays.Results: Our results show that 1 of 15 dogs had an elevated CTnT, 6 had an elevated CTnI, 0 had an elevated pro‐BNP, and 3 had and elevated BNP level above laboratory normal values.Conclusions: There was no consistent elevation of CTnI, CTnT, BNP or pro‐BNP in dogs with class IV CHF due to MR at time of presentation. Further studies need to be performed to evaluate these makers in dogs with CHF due to MR at varying intervals after admission to determine their potential benefits as markers of cardiac injury and response to therapy.