Changes in mechanical dyssynchrony in severe aortic stenosis patients undergoing transcatheter aortic valve replacement.

INTRODUCTION: Aortic stenosis (AS) imposes a significant afterload on the left ventricle, but regional manifestations of the overall load may not be uniform, leading to mechanical dyssynchrony. Accordingly, we evaluated the prevalence of dyssynchrony in patients with severe AS at baseline as well as changes after transfemoral aortic valve replacement (TAVR). METHODS: This study is a retrospective analysis of 225 patients in sinus rhythm who underwent TAVR for severe AS, in whom inter-ventricular and intra-ventricular dyssynchrony were measured at baseline, discharge, 1 month, and 1 year. Inter-ventricular dyssynchrony was defined as the difference between left and right ventricular pre-ejection intervals; intra-ventricular dyssynchrony was defined as the difference between time to peak systolic velocity of the basal septal and lateral segments. Patients were further stratified into those with QRS <120 ms or >120 ms. RESULTS: At baseline, a quarter of patients met the criterion for significant inter-ventricular dyssynchrony, and a third had evidence of intra-ventricular dyssynchrony. Both decreased after TAVR although only the intra-ventricular dyssynchrony reached statistical significance. The interplay between QRS duration and changes in inter- and intra-ventricular dyssynchrony are also explored. CONCLUSIONS: In patients with severe AS, there was evidence of mechanical dyssynchrony that is improved post-TAVR. Whether dyssynchrony is clinically and prognostically significant, and if it represents a potential target for additional therapy remains to be studied.

Effect of transcatheter aortic valve replacement on left atrial function.

OBJECTIVES: To investigate the effect of transcatheter aortic valve replacement on left atrial volumetric function and left atrial volume for the prediction of adverse outcomes. METHODS: This is a retrospective analysis of 121 patients in sinus rhythm who underwent TAVR for severe AS. Maximum LA volume index (LAVI max), minimum LA volume index (LAVI min), and "pre-A" volume index (LAVIpre-A, the volume before atrial contraction) were measured by biplane Simpson's method at baseline, 1 month, and 1 year. The reservoir function, conduit function, booster pump function were calculated. All patients were followed for new-onset of atrial fibrillation, hospitalization and all-cause mortality. RESULTS: The reservoir function, conduit function and booster function before TAVR were 46%, 21%, 32%, respectively. LA volumetric function assessment demonstrated that reservoir function, conduit function increased over the time (all P < 0.01). There was no difference in booster function after TAVR (P = 0.18). Baseline markedly enlarged LA was significantly increased for AF (HR: 4.72; 95% CI, 1.11-20.13, P = 0.04). In addition, There was a progressive decrease in LAVI max (P = 0.02) and RVSP (P = 0.03) over the time in non-AF group but not in AF group (P = 0.62 and P = 0.65, respectively). Although, the proportion of high left ventricular filling pressure decreased in both groups but a marked decrease was noted in non AF group in compared with AF group. CONCLUSION: Reservoir function, conduit function increased over time. Lack of negative LA remodeling post TAVR was associated with higher incidence of AF.