Diagnostic value of echocardiographic indices and cardiac biomarkers in dogs with chronic mitral valve insufficiency

Abstract

Because all dogs having heart diseases are not in symptomatic heart failure stage, it is important to determine the stage of heart failure in dogs with heart diseases. Therefore, this study evaluated the diagnostic value of several echocardiographic parameters and cardiac biomarkers for differentiating dogs with heart disease from healthy dogs and dogs with symptomatic heart failure from dogs with asymptomatic heart failure. The study population consisted of 51 dogs having chronic mitral valvular insufficiency (CMVI) with varying degrees of heart failure and 18 healthy control dogs. Several echocardiographic parameters and cardiac biomarkers were evaluated to achieve the study aims. The study found that there were significant differences in indexed left atrial diameter (iLA), left atrial to aorta ratio (LA/Ao), left ventricular diastolic dimension to aorta ratio (LVIDd/Ao), transmitral E-peak (E-peak), septal E/Ea ratio (sE/Ea), parietal E/Ea ratio (pE/Ea) and N-terminal probrain natriuretic peptide (NT-proBNP) between the control dogs and the CMVI dogs (P<0.05), and also between the asymptomatic dogs and the symptomatic dogs (P<0.05). The cut-off values for indicating heart disease in this study population were iLA >11.9 mm, LA:Ao >1.32, LVIDd/Ao >1.91, E-peak >80 cm/sec, sE/Ea >7.0, pE/Ea >6.9, and NT-proBNP >980 pmol/L, while the cut-off values for indicating heart failure were iLA >12.7 mm, LA:Ao >1.58, LVIDd/Ao >2.08, E-peak >90 cm/sec, sE/Ea >9.0, pE/Ea >8.9, and NT-proBNP >1200 pmol/L. This study found that iLA, LA/Ao, E-peak, E/Ea and NT-proBNP were the most reliable and consistent markers for detecting heart disease and differentiating symptomatic heart failure dogs from asymptomatic dogs with CMVI.