Anterior mitral valve leaflet length in cats with hypertrophic cardiomyopathy.

Abstract

INTRODUCTION: Anterior mitral valve leaflet (AMVL) elongation is a recognised feature of hypertrophic cardiomyopathy (HCM). However, whether AMVL elongation precedes left ventricular hypertrophy&#xa0;in cats is currently unknown. The aim of this study was to explore the risk of developing an HCM phenotype in cats with an elongated AMVL. ANIMALS: FIFTY-FIVE APPARENTLY HEALTHY CATS WITH A NORMAL BASELINE ECHOCARDIOGRAM AND A FOLLOW-UP ECHOCARDIOGRAM AT >ONE YEAR. MATERIALS AND METHODS: This was a retrospective longitudinal study. Cats at the baseline were grouped based on whether or not they developed an HCM phenotype at follow-up. AMVL length and left atrial and left ventricular&#xa0;dimensions were measured from two-dimensional images. RESULTS: The median follow-up period of the study population was 5.4 years (25th and 75th quartile, 2.7-6.7 years). During this time, 17 cats (30.9%) developed an HCM phenotype. At the baseline, cats that subsequently developed an HCM phenotype had greater AMVL length (9.4&#xa0;mm [25th and 75th quartile, 9.0-10.6 mm] vs. 8.5&#xa0;mm [25th and 75th quartile, 7.6-9.1 mm], P&#xa0;<&#xa0;0.0001) and maximal left ventricular wall thickness (4.5&#xa0;mm [25th and 75th quartile, 4.1-4.7 mm] vs. 4.0&#xa0;mm [25th and 75th quartile, 3.7-4.6 mm], P&#xa0;=&#xa0;0.007) than those that did not. Multiple logistic regression analysis confirmed that both baseline variables were independent predictors for development of an HCM phenotype. CONCLUSIONS: The AMVL length was greater in cats that subsequently developed left ventricular hypertrophy. Further studies investigating the clinical application of AMVL in the natural history of feline HCM are warranted.