Area strain from 3D speckle-tracking echocardiography as an independent predictor of early symptoms or ventricular dysfunction in asymptomatic severe mitral regurgitation with preserved ejection fraction.

ABSTRACT

The indication for surgery in asymptomatic severe mitral regurgitation (SMR) with preserved left ventricular ejection fraction (LVEF) is controversial. We sought to study 3D myocardial mechanics in this population and test 3D-speckle tracking (3DST) parameters as possible predictors of events. 45 asymptomatic patients with SMR and LVEF >60 % and 20 control individuals without cardiac disease underwent 3DST echocardiography. MR group additionally underwent further clinical monitoring. Dyspnea, LVEF under 60 %, or admissions for heart failure were considered as events. When compared with control group, MR group showed lower percentage of global 3D strain, (35.4 ± 9.1 vs. 43.9 ± 10.6; p = 0.003), lower radial strain, lower area change rate and higher end-diastolic volume. In a follow-up time of 23.2 ± 14.5 months we found 15 events (33.3 %). When comparing the remaining patients with this new-onset HF group we found significant differences in longitudinal strain (-17.9 ± 3.3 vs. -15.8 ± 2.1; p = 0.036), area strain (AS) (-48.6 ± 4.6 vs. -43.7 ± 6.2; p = 0.006), circumferential strain (-35.8 ± 4.7 vs. -31.8 ± 6.1; p = 0.034), 3D LVEF (67.1 ± 4.6 vs. 63.0 ± 7.4; p = 0.034) and E/E' index (13.5 ± 3.9 vs. 19.3 ± 9.5; p = 0.006). In multivariate Cox regression AS alone was the only independent predictor. A cutoff value of AS greater than -41.6 % reached a hazard ratio of 4.41 (p = 0.004) for prediction of events. In asymptomatic patients with SMR and preserved ejection fraction, 3DST derived AS is a promising tool for predicting the development of heart failure. This finding may be useful for guiding the selection of patients for early mitral valve repair/replacement surgery even if they are asymptomatic.