Ischemic mitral valve regurgitation in patients with depressed ventricular function: cardiac geometrical and myocardial perfusion evaluation with magnetic resonance imaging.

OBJECTIVE: To investigate geometrical and functional changes involving the left ventricle (LV) and mitral valve (MV) apparatus in patients with depressed LV ejection fraction (LVEF) and ischemic MV regurgitation (IMVR).
METHODS: A series of patients with three vessels coronary artery disease (CAD) and depressed LVEF underwent cardiac magnetic resonance imaging to investigate MV/LV geometry and function, and myocardial perfusion/vitality. Geometrical data were indexed by anterior MV leaflet length. Two groups were identified: CAD without IMVR (group CAD), and with IMVR (group IMV).
RESULTS: Eleven patients were enrolled in the CAD group and 13 in the IMV group. IMVR volume was significantly higher in the IMV group (24.0+/-12.0 vs 4.5+/-5.2; p<0.0001). LVEF% was comparable (IMV 34.6+/-13.0 vs CAD 31.5+/-13.0; p=ns). Indexed MV/LV geometrical variables were comparable in the two groups. Perfusion/vitality study showed inferior myocardial necrosis occurred more often in the IMV group (p=0.01). At Pearson test, MV regurgitation occurrence correlated with inferior myocardial necrosis (r=0.5; p=0.006), non-indexed systolic/diastolic annular inter-commissural diameters (r=0.4; p=0.04) and MV annular areas (r=0.4; p=0.04). Papillary muscles distance (PMD) and LV volumes inversely correlated with LVEF% (r=-0.6; p<0.05 and r=-0.8; p<0.001). At multivariable analysis, no independent determinants for IMVR were identified and LV volumes were the sole determinants for LVEF% (p<0.05).
CONCLUSION: In patients with depressed LVEF%, IMV cannot be explained by LV geometrical modifications alone. Although PMD, LV volumes, and LVEF% are correlated, they have no direct impact in the development of IMVR. In contrast, inferior myocardial necrosis and increased inter-commissural MV diameters may lead to deformity of MV complex and subsequent IMV.