Correlation between the Mitral INsufficiency Echocardiographic score and radiographic variables in dogs with myxomatous mitral valve disease

Myxomatous mitral valve disease (MMVD) in dogs can progress gradually with left atrial enlargement. In veterinary medicine, several radiographic variables including the vertebral heart size (VHS), vertebral left atrial size (VLAS), modified VLAS (M-VLAS), and radiographic left atrial dimension (RLAD) are used to assess cardiac enlargement. The Mitral INsufficiency Echocardiographic (MINE) score, which provides an echocardiographic assessment of the severity of MMVD, has recently been used as a predictor of cardiac death. This study aimed to evaluate the correlation and cut-off values between the MINE score and radiographic variables. A total of 132 dogs with MMVD were recruited. The correlation between radiographic variables and the MINE score was assessed using Pearson's correlation analysis. Receiver operating characteristic (ROC) curves and the corresponding area under the curve (AUC) values and 95% confidence intervals (CIs) were generated for radiographic variables using a MINE score over 8 (severe) as the classifiers. The MINE score showed a positive correlation with the VHS, VLAS, M-VLAS, and RLAD. For a cut-off MINE score ≥ 8 (severe), the radiographic variables could be ranked from highest to lowest AUC value as follows: VHS, VLAS, M-VLAS, and RLAD with cut-off values of 10.75, 2.75, 4.05, and 2.45, respectively. The results of this study highlight the potential of thoracic radiography as an alternative method for providing valuable prognostic insights in dogs with MMVD.