437 Ultrasonic myocardial tissue characterization by cyclic variation of integrated backscatter in patients with aortic stenosis

Abstract

Background: Ultrasonic myocardial tissue characterization by cyclic variation of integrated backscatter (CVIBS) has been successfully used for the differentiation of various myopathies from normal myocardium.Aim: The aim of the study was ultrasonic myocardial tissue characterization in patients with aortic stenosis (AS) by cyclic variation of integrated backscatter.Methods: The study population consisted of 128 patients (42 women; mean age 65±10 years).In the parasternal long-axis view two regions of interest were chosen to estimate CVIBS: the mid-septum and the mid-posterior wall.Types of left ventricular remodeling in our group were classified according to left ventricular mass index (LVMI) and relative wall thickness (RWT): normal LV (N), LV concentric remodeling (CR), LV concentric hypertrophy (CH) and LV excentric hypertrophy (EH).Results: The mean echocardiographic parameters were: the aortic valve area (AVA) 0.8±0.3cm 2 , maximal pressure gradient (PG max) 86±29 mm Hg and mean pressure gradient (PG mean) 54±20 mm Hg, LVEF 71±14%, fractional shortening (FS) 35±10%, left LVMI 146±47 mg, circumferential end-systolic wall stress (cESS) 102±48 kdynes/cm 2 ; CVIBS septum 5.6±2.3db, CVIBS posterior wall 5.4±2.0 dB.We found inverse correlation between mean CVIBS and LVMI (r=-0.29;r=-24; p<0.05; for septum and posterior wall respectively) and cESS (r=-0.28;r=-32; p<0.05; for septum and posterior wall respectively) and direct correlation between mean CVIBS and LVEF (r=0.28;r=-25; p<0.05; for septum and posterior wall respectively) and FS (r=0.26;r=-22 p<0.05; for septum and posterior wall respectively).In addition mean CVIBS for both septum and posterior wall was significantly lower in group with LV excentric hypertrophy compared to patients with LV concentric remodeling and LV concentric hypertrophy (Table 1).There were no significant correlations between mean CVIBS and NYHA, AVA, PG max, PG mean and diastolic function indices. Conclusion:The severity of myocardial dysfunction and left ventricle remodeling in patients with aortic stenosis are associated with alterations in myocardial ultrasonic reflectivity detected by integrated backscatter analysis.