Short-Term Effects of Transcatheter Aortic Valve Implantation on Left Atrial Mechanics and Left Ventricular Diastolic Function

Abstract

Aortic stenosis (AS) leads to remodeling of the left heart. Strain measurements enable the assessment of left atrial (LA) mechanics. The goal of this study was to evaluate the short-term effects of transcatheter aortic valve implantation (TAVI) on LA myocardial deformation as well as left ventricular (LV) diastolic function. Thirty-two patients with severe AS were prospectively enrolled and examined before and 8.2 ± 3.3 days after TAVI. Speckle-tracking echocardiography of the basal septal and lateral segments of the left atrium was performed to determine peak positive strain (R(LA)), strain during early diastole (E(LA)), and, if feasible, strain during atrial contraction (A(LA)). Assessment of LV diastolic function included standard indices, the atrial fraction, and LA volumes. Compared with baseline, the mean atrial reservoir (R(LA)) (24.0 ± 11.2% vs 32.2 ± 14.0%, P < .001) and conduit function (R(LA) - E(LA)) (13.9 ± 5.5% vs 20.8 ± 8.1%, P < .001) improved significantly after TAVI. There was a significant reduction in deceleration time (242 ± 56 vs 195 ± 65 msec, P < .001) and an improvement of pulsed-wave tissue Doppler-derived E' (5.5 ± 1.8 vs 7.3 ± 2.3 cm/sec, P = .01). Regarding LA volumes, only the minimal LA volume index changed significantly. In contrast, there was no improvement in atrial contraction, that is, contractile function (E(LA) - A(LA)) and atrial fraction. Moreover, the E/E' ratio remained unchanged. 8.2 ± 3.3 days after TAVI, only the reservoir and conduit function of the left atrium improved, whereas LA contraction and LA volumes, except for the systolic volume index, remained unchanged. This was accompanied by improvement of early LV diastolic function, indicating acute recovery of LV relaxation and LA function.