Ischemic Mitral Regurgitation: Echocardiographic Algorithm, the Place of Three-Dimensional Transesophageal Echocardiography

Abstract

Objective Identify the diagnostic markers of the severe MV changes in patients with ischemic mitral regurgitation (IMR) and suggest a modification of the echocardiography (EchoCG) algorithm.Materials and Methods A two-stage examination of 65 patients with mild (n=22), moderate (n=22), and severe (n=21) IMR was performed using two-dimensional (2D) transthoracic EchoCG with dopplerography, 2D and three-dimensional (3D) transesophageal EchoCG (TEE). 4D MV-Assessment in off-line mode was made in TomTec Imaging Systems GmbH, Germany. Statistical analysis (SAS 9.4) included Student's t-test, Kruskal-Wallis method, Pearson correlation, multivariate regression analysis, and ROC-analysis.Results According to 3D TEE the significant changes in MV annulus, leaflets and tenting are detected. 3D parameters of MV geometry are related to IMR severity, left ventricle (LV) remodeling (global and regional), and they are different in symmetric and asymmetric variants. In symmetric variant MV reconstruction is correlated with LV dilatation and contractility decrease, in asymmetric variant it's correlated with regional remodeling parameters. Severe IMR is characterized by a decrease in MV annulus displacement (27,0±6,6 mm/s versus 32,4±10,8 mm/s in mild IMR; р<0,05), tenting volume fraction (32,5±14,8% versus 56,2±16,8% in mild IMR; p<0,05), and annulus area fraction (4,7±2,7% versus 6,6±4,5% in mild IMR; р<0,05). Vena contracta width (VCW), Proximal Isovelocity Surface Area (PISA) radius, Effective Regurgitant Orifice Area (EROA), Regurgitant Volume (Rvol), LV end systolic dimension (LV ESD), and central large jet >50% of left atrium (LA) area have a predictive value in the diagnosis of MV geometry severe changes. If thresholds are reached these 2D TTE parameters can be used as indications for the 3D TEE.Conclusion 3D TEE allows for detailed assessment of MV geometry and function depended on IMR severity and variant. To make decision of MV surgery 3D TEE is recommended if the following indicators are presented: (1) VCW ≥0,7 cm; PISA radius ≥1,0 cm; central large jet >50% of LA area; LV ESD ≥4,0 cm; (2) VCW ≥0,6 cm; PISA radius = 0,6-0,99 cm; EROA ≥0,3 cm2; RVol≥45 cm; IMR eccentric jet + IMR elliptical orifice.