New classification of heart failure severity using mitral annulus displacement measured by tissue-tracking method with Doppler-tissue images

Objectives. The purpose of this study was to determine whether the assessment of mitral annulus displacement (MAD) using Doppler-tissue image (DTI) could provide a useful marker of heart failure severity. Methods. In seventy-five subjects with heart diseases, we measured MAD by tissue-tracking method with DTI. MAD was evaluated in both septal and lateral corners of the mitral annulus in the apical 4-chamber view, and the degree of MAD in postsystolic phase was estimated as a ratio of displacement at aortic valve closure and peak point (P/A ratio). We divided subjects into three groups (group A: subjects with preserved MAD, group B: subjects with reduced MAD without increasing P/A ratio, group C: subjects with reduced MAD with increasing P/A ratio) and compared NYHA functional class and left ventricular ejection fraction (LVEF). Results. NYHA functional class and LVEF were significantly different among the three groups (NYHA functional class; group A: 1.2 ± 0.4, group B: 2.3 ± 0.9, group C: 3.1 ± 0.8, LVEF; group A: 58 ± 12 %, group B: 42 ± 15 %, group C: 25 ± 8 %). These results indicated that MAD which represents mainly LV longitudinal function is decreased in the first place, and then, post-systolic displacement is exaggerated according to the severity of heart failure. Conclusions. The classification of the degree and timing of peak MAD (P/ A ratio) is well correlated with NYHA functional class and LVEF and becomes one of the useful indexes of heart failure severity.