Tissue Doppler Imaging For Evaluation And Prediction Of Severe Organic Mitral Regurgitation Caused By Left Ventricular Dysfunction And Expansion

Background:Chronic significant mitral regurgitation(MR)from flail or prolapsed mitral valve(MV)may result in left ventricular(LV)dysfunction and dilation.However,its progression and predictors are not well defined.In particular,no study has utilized tissue Doppler(TD)imaging.We assess the natural history and hypothesize that TDI predict LV decompensation.Methods:Consecutive patients(n=153,54±17yrs)with at least moderate organic MR(≥GradeⅢ),preserved LV ejection fraction(EF≥55%)were included.Paired TD at the mitral annulus(lateral and septal)and conventional echocardiograms were performed at an interval of 650±362 days apart. Patients were categorized into 2 groups:with or without LV dilation(interval increase in end-systolic volume(ESV)of＞20%).Results:There were significant increases in body-surface area indexed biplane ESV(17±5 to 20±6 ml/m~2,P＜0.001);end-diastolic volume(49±12 to 55±13 ml/m~2,P＜0.001);left atrial(LA)volume(35±14 to 42±17 ml/m~2,P＜0.001);MR severity;E/E' and decreases in early diastolic TD velocities(E').However LVEF, LAEF,TD systolic(S'),and late diastolic(A')velocities remained the same. There were 40 patients(26%)with progressive LV dilation.Compared to the group without LV dilation,they had lower baseline S',A' velocities and LAEF. Time interval between studies and baseline MR volumes were similar between the 2 groups.ESV change between baseline and follow-up correlated well with these univariate predictors。Multivariate analysis showed that lateral A' was the only independent predictor of LV dilation(P＜0.001).The area under receiver-operator-characteristic curve was 0.78(95%CI 0.70-0.86).An optimized cut-off of A'＜11.0cm/s predicted subsequent LV dilation with 90% sensitivity and 64%specificity.Conclusions:Organic significant MR resulted in progression in severity,LV and LA remodeling with time.Reduced baseline lateral A'(LA subclinical dysfunction)appeared to predict subsequent LV dilation.Monitoring of this easily obtainable parameter is warranted.