Prognostic value of early-diastolic left ventricular untwisting in asymptomatic patients with chronic degenerative mitral valve regurgitation.

Purpose: To assess whether an impaired cardiac mechanics may affect prognosis in patients with degenerative mitral regurgitation (MR). Methods: 42 asymptomatic patients (mean age 61+18 years) with MV prolapse and moderate to severe MR with LV ejection fraction (EF) ≥ 50% were prospectically enrolled. An effective orifice regurgitant area (EROA) ≥ 0.40 cm2 and a vena contracta (VC) ≥ 0.7 mm were considered to define as severe MR. LV mass index, relative wall thickness (RWT) and sphericity index were calculated. 2D images of left cardiac chambers were acquired for speckle tracking analysis. End-systolic (ES) peak of overall LV strains, basal and apical rotations, twist and early-diastolic (ED) untwisting rate (recoil) were measured. Left atrial (LA) strain (reservoir) was also calculated. The following endpoint were considered: sudden death, dyspnoea, arrhythmia, symptoms on exercise-echo, MV surgery, hospitalization for heart failure and/or arrhythmia. Results: After a mean follow-up of 30 months, only 18 (43%) patients were asymptomatic whereas 24 (57%) developed events (16=MV surgery, 8=dyspnoea, 11=arrhythmia, 3=positive exercise-echo). Compared to asymptomatic patients, those with events showed higher: LV diameters (EDD=55+7.1 vs 50+4.3, p=0.009; ESS=32+5.6 vs 27+7.4, p=0.025), LV mass idex (103.8+21.7 vs 85.3+21.5, p=0.01), LA indexed volume (53.1+16.4 vs 35.2+4.7, p , 0.001), EROA (0.42+ 0.2 s 0.27+0.1, p =0.0039, VC (7.1+1.9 vs5.5+1.4, p=0.003), E/E’ (15.1+8.6 vs 10.4+2.3, p=0.002) and PAPs (40.2+16.8 vs 25.2+7.6, p=0.002), whereas RWT (0.35+0.07 vs 0.4+0.05, p=0.029), LV sphericity index (0.65+0.07vs 0.57+0.5, p , 0.001), LA strain (27.8+10 vs37+5, p=0.002) and LV recoil (267.5+20.5 vs-112.8+30.3, p , 0.001) were lower in patients with events than in those asymptomatic. On univariate Cox regression analysis, LV mass index (p=0.004), LA volume (p , 0.001), EROA (p=0.004), VC (p=0.006), PAPs (, 0.001), LA strain (p=0.001), E/E’ (p=0.003) and LV recoil (p , 0.001) were associated with increased risk of events. On multivariate regression analysis, only LV recoil was independent predictor of events (HR=1.1 95% CI 1.0 to 1.2, p=0.010). The ROC analysis showed that a cut-off recoil= -858/sec had the higher sensitivity and specificity to identify patients at major risk (AUC=0.91; Sensitivity 82 %, Specificity 77 %).