Left atrial remodelling in patients undergoing transcatheter aortic valve implantation: a speckle-tracking prospective, longitudinal study

Aortic stenosis (AS) results in several left ventricular (LV) disturbances as well as progressive left atrial (LA) enlargement and dysfunction. Transcatheter aortic valve implantation (TAVI) reverses LV remodelling and improves overall systolic function but its effect on LA function remains undetermined. The aim of this prospective, longitudinal study was to investigate the effects of TAVI on LA structure and function. We studied thirty-two patients with severe symptomatic AS who underwent TAVI, using standard and 2-dimensional speckle-tracking echocardiography before, at 40-day and at 3-month follow-up. Following TAVI, mean transvalvular gradient decreased (p < 0.001). Both LA area index and LA volume index decreased at 40-day follow-up (16.2 ± 6.4 vs. 12.5 ± 2.9 cm2/m2, and 47.3 ± 12.0 vs. 42.8 ± 12.5 mL/m2, respectively, p < 0.05) and values remained unchanged at 3 months. The reduction of LA size was accompanied by a significant increase in global peak atrial longitudinal strain (14.4 ± 3.9 vs. 19.1 ± 4.7 %, p < 0.001) and in global peak atrial contraction strain (8.4 ± 2.5 vs. 11.0 ± 4.1 %, p < 0.05) at 3-month follow-up. LA stiffness measurements significantly decreased 3 months after TAVI (0.93 ± 0.59 vs. 0.65 ± 0.37, respectively, p < 0.001). Trans-aortic mean gradient change and pre-procedural LA volume were identified as predictors of global peak atrial longitudinal strain increase (β = -0.41, β = -0.35, respectively, p < 0.0001) while pre-procedural LA volume and trans-aortic mean gradient change as predictor of LA volume index reduction 3 months after TAVI (β = -0.37, β = -0.28, respectively, p < 0.0001). TAVI is associated with significant recovery of LA structure and function suggesting a reverse cavity remodelling. Such functional recovery is primarily determined by the severity of pre-procedural valve stenosis.