Graduate School Veterinarian Hokkaido University Sapporo, Hokkaido, Japan
Abstract: Background：Cardiac disease cause hepatic congestion and fibrosis, which increase liver stiffness (LS). LS can be estimated by 2D-Shear Wave Elastography (SWE), which measures shear wave speed (SWS), an index of viscoelasticity and dispersion slope (DS), an index of viscosity. In the liver, fibrosis elevates elasticity, while congestion or inflammation elevates viscosity.
Hypothesis/Objectives：To analyze SWE-measured LS in dogs with cardiac disease and to identify its determinants.
Animals：Sixty-five client-owned dogs with cardiac disease.
Methods：In this cross-sectional prospective study, SWS and DS were measured using 2D-SWE in all dogs along with the short to long diameter ratio of the caudal vena cava (CVC SD/LD), an index of congestion, and the left ventricular outflow tract velocity time integral (LVOT-VTI), an index of cardiac output by echocardiography. The discriminatory ability of these parameters for right heart failure (RHF) was compared using ROC analysis. The relation of SWS and DS to other echocardiographic indices was evaluated by multiple regression analysis.
Results：SWS, DS and CVC SD/LD were all significantly higher, while LVOT-VTI was significantly lower in the dogs with RHF. DS had the highest accuracy in discriminating RHF (AUC=0.998), followed by SWS (AUC=0.992). In multiple regression analysis, CVC SD/LD was the most related factor to the SWS and DS followed by LVOT-VTI.
Conclusions and clinical importance： Elevated SWS and DS in dogs with RHF reflects congestion and reduced cardiac output. 2D-SWE may be useful to predict the presence of hepatic congestion and RHF in dogs with cardiac disease.
