Detection of congestive heart failure by mitral annular displacement in cats with hypertrophic cardiomyopathy – concordance between tissue Doppler imaging–derived tissue tracking and M-mode

Introduction: The left ventricular systolic longitudinal function, traditionally measured by M-mode–derived mitral annular plane systolic excursion (MAPSE), is reduced in feline hypertrophic cardiomyopathy (HCM) and further reduced in cats with left-sided congestive heart failure (CHF). The objectives of this study were to compare longitudinal displacement measured by tissue tracking (TT-LD) and MAPSE in feline HCM and assess these methods’ ability to differentiate CHF from preclinical HCM. A further objective was to provide preliminary reference intervals for TT-LD. Animals: Eighty-five client-owned cats. Methods: A retrospective case–control study. Anatomical M-mode was used to record MAPSE, and TT-LD was recorded by tissue tracking. Results: Reduced longitudinal displacement measured by either MAPSE or TT-LD was significantly associated with CHF in cats with HCM (p < 0.036). Receiver-operating characteristic analysis indicated that TT-LD (AUC: 92.9%–97.9%) was more sensitive and specific than MAPSE (AUC: 85.8%–89.1%) for the detection of CHF. A diagnostic cut-off of 2.89 mm for maximal TT-LD in the left ventricular septum resulted in a sensitivity and specificity of 100% and 83.3%, while a diagnostic cut-off of 2.41 mm in the left ventricular posterior wall resulted in a sensitivity of 100% and a specificity of 90%. Conclusions: M-mode–derived mitral annular plane systolic excursion and TT-LD were strongly correlated, but not interchangeable. Longitudinal displacement measured by tissue tracking decreased more with disease severity than traditional MAPSE. Longitudinal displacement may help detect CHF in cats with HCM – with the maximal TT-LD of the left ventricular posterior wall achieving the highest AUC value.