Left atrial dysfunction assessed by strain correlates with symptoms and severity of aortic stenosis

Abstract Background Aortic stenosis (AS) results in high pressure afterload causing detrimental effect especially on the left chambers. Structural and functional changes of the left ventricle (LV) usually corresponds to concomitant remodelling of the left atrium (LA). However, how this pressure afterload specifically affects LA function and whether the study of LA function could help in stratifying patients with different degree of AS it is not known. Purpose We aim to evaluate the differences in LA and LV function according different degree of AS by standard and speckle tracking echocardiographic. Methods From January 2016 to May 2018 we recruited 135 patients referring to our echo-lab with diagnosis of AS (mean age 79.5±4.4; 60/55% female). We divided this population according to AS severity in patients with moderate AS, severe asymptomatic and severe symptomatic AS and matched with 35 control group with no aortic stenosis (n=45, mean age: 77.6±4.5). All patients underwent standard and 2-dimensional speckle tracking echocardiography computing global longitudinal strain (GLS) of LV and peak atrial strain of LA (PALS). Results In all patients PALS was a good predictor of E/e' ratio after correction for LV EF and age (p<0.001, β: −0.48). LVEF and GLS progressively decreased together with worsening of AS degree, as well as parameters of geometry and function of LA (Table1). By excluding patients with LV dysfunction the reduction gradient of parameters of LA geometry and function was still present. However, when severe symptomatic with asymptomatic severe AS are compared, no difference in E/e' ratio was found while both GLS and PALS were significantly reduced (both p<0.0001). Variables Overall population (180) Control (45) Moderate AS (45) Severe asympt AS (45) Severe sympt. AS (45) p LVEF 65.0±11.1 67.7±5.6 69.4±8.5 66.1±10.7 59.5±13.5 0.0001 GLS −20.4±4.1 −23.1±2.4 −21.5±2.9 −21.4±3.2 −17.1±4.3 0.0001 LA vol index 41.6±21.5 28.2±10.4 40.1±19.7 39.8±16.7 52.3±24.9 0.0001 LA strain 23.6±10.9 30.8±10.3 27.8±9.2 24.4±9.7 15.2±7.1 0.0001 LA reservoir 46.4±15.9 51.9±11.5 53.0±15.0 48.3±14.1 37.2±16.1 0.0001 Ee' ratio 14.8±7.0 9.6±2.7 13.7±6.3 15.4±6.2 19.3±7.2 0.0001 Conclusions LA function seems to progressively decrease according to the degree of AS, independently from LV function. Significant difference was found between parameters of LA remodelling and dysfunction between symptomatic and asymptomatic AS patients. The assessment of LA function by strain may help stratify the patients with AS, identifying those who need intensive medical/surgical treatment.