The Mitral INsufficiency Echocardiographic score: A severity classification of myxomatous mitral valve disease in dogs

Abstract

Background: There is no commonly shared severity score for myxomatous mitral valve disease (MMVD) based on routinely acquired echocardiographic variables. Hypothesis/Objectives: To propose an easy-to-use echocardiographic classification of severity of MMVD in dogs. Animals: Five hundred and sixty dogs with MMVD. Methods: This was a retrospective, multicenter, observational study. The proposed Mitral INsufficiency Echocardiographic (MINE) score was based on 4 echocardiographic variables: left atrium-to-aorta ratio, left ventricular end-diastolic diameter normalized for body weight, fractional shortening, and E-wave transmitral peak velocity. Specific echocardiographic cutoffs were defined based on previous prognostic studies on MMVD, and severity scores were assigned as follows: mild (score: 4-5), moderate (score: 6-7), severe (score: 8-12), late stage (score: 13-14). Results: Median survival time was significantly different (P 8 was predictive of cardiac death (area under the curve = 0.85; P