P1785 Hemodynamic determinants of left atrial function in patients with primary mitral regurgitation

Abstract

Background 2D speckle tracking (2DSE) has been recently used as an advanced method for assessment of left atrial (LA) function. Purpose The aim of the study was to determine the association between LA function assessed with 2DSE and severity of mitral regurgitation, filling pressures and symptomatic status in patients with primary mitral regurgitation (MR). Methods 61 patients (age 65 ± 9 years, 77% males) with primary mitral prolapse and moderate to severe MR (effective regurgitant orifice (ERO) > 0.30 cm2) and left ventricular ejection fraction > 60% were enrolled. Right heart catheterization during rest and exercise, and transthoracic echocardiography during rest was performed. Pulmonary capillary wedge pressure (PCWP) was measured at rest and peak exercise. Echocardiographic average values of LA peak contractile, conduit and reservoir strain were obtained using 2DSE in the apical 4 and 2 chamber views. Results LA volume index was less than 34 ml/m2 in 54 patients, and LA function based on 2DSE was abnormal in majority. LA function was associated with ERO (Figure). Patients with severe MR defined as ERO > 0.40 cm2 had significant higher reservoir strain (27.5 ± 5.1% vs. 24.5 ± 5.1 %, p = 0.02) and conduit strain (16.0 ± 4.9 %, vs. 13.1 ± 3.2 %, p = 0.008), but LA peak contractile strain was unchanged (11.4 ± 3.4 % vs. 11.8 ± 3.5 %, p = 0.69). In contrast no association between LA function, symptoms and PCWP at rest or exercise was found in our cohort. In linear regression analysis MR (ERO > 0.40 cm2) was associated with conduit (β=2.8, p = 0.02) and reservoir strain (β=3.0, p = 0.04) after adjustment for age, gender, symptoms and PCWP with exercise, whereas LA peak contractile was not. Conclusions LA function assessed with 2DSE was affected in patients with primary MR. Strain parameters were associated with severity of mitral regurgitation, but there was no association with symptomatic status or filling pressure at rest or exercise. Abstract P1785 Figure