Aortic annular plane systolic excursion in cats with hypertrophic cardiomyopathy

Background: Impairment of left ventricular (LV) longitudinal function is an early marker of systolic dysfunction in hypertrophic cardiomyopathy (HCM). Aortic annular plane systolic excursion (AAPSE) is a measure of LV longitudinal function in people that has not been evaluated in cats.Hypothesis: Aortic annular plane systolic excursion is lower in cats with HCM compared to control cats, and cats in stage C have the lowest AAPSE.Animals: One hundred seventy-five cats: 60 normal, 61 HCM stage B and 54 HCM stage C cats.Materials: Multicenter retrospective case-control study. Electronic medical records from 4 referral hospitals were reviewed for cats diagnosed with HCM and normal cats. HCM was defined as LV wall thickness >= 6 mm and normal cats <= 5 mm. M-mode bisecting the aorta in right parasternal short-axis view was used to measure AAPSE.Results: Aortic annular plane systolic excursion was lower in HCM cats compared to normal cats (3.9 +/- 0.9 mm versus 4.6 +/- 0.9 mm, P < .001) and was lowest in HCM stage C (2.4 +/- 0.6 mm, P < .001). An AAPSE <2.9 mm gave a sensitivity of 83% (95% CI 71%-91%) and specificity of 92% (95% CI 82%-97%) to differentiate HCM stage C from stage B. AAPSE correlated with mitral annular plane systolic excursion (r = .6 [.4-.7], P < .001), and atrial fractional shortening (r = .6 [.5-.7], P < .001), but showed no correlation with LV fractional shortening. Conclusions and Clinical Importance: Aortic annular plane systolic excursion is an easily acquired echocardiographic variable and might be a new measurement of LV systolic performance in cats with HCM.