The influence of transcatheter aortic valve replacement on left atrial mechanics: a systematic review and meta-analysis.

Aims: The morphology and function of the left atrium (LA) are intimately tied to left ventricular loading conditions. Data pertaining to the effect of transcatheter aortic valve replacement (TAVR) on LA function and geometry are scarce. The aim of the study was to quantify associations between TAVR and LA remodelling by pooling available data from published observational studies.

Methods and results: A systematic review and meta-analysis were performed. Studies reporting serial LA speckle-tracking echocardiographic (STE) data, before and after TAVR, were included. Other outcome data included LA area and indexed volume (LAVi) and standard chamber measurements. Outcomes were stratified by timing of follow-up echocardiography: early (<6 months) or late (≥6 months). Twelve studies were included, comprising 1066 patients. The mean reduction in LAVi was 2.72 mL/m² [95% confidence interval (CI) 1.37-4.06, P < 0.01]. LA reservoir function improved overall by a mean difference (MD) of 3.71% (95% CI 1.82-5.6, P < 0.01), although there was significant heterogeneity within the pooled studies (I ² = 87.3%). Significant improvement in reservoir strain was seen in both early follow-up (MD 3.1%, P < 0.01) and late follow-up studies (MD 4.48%, P = 0.03), but heterogeneity remained high (I ² = 65.23 and 94.4%, respectively). Six studies reported a change in LA contractile function, which recovered in the early follow-up studies (MD 2.26, P < 0.01), but not in the late group (MD 1.41, P = 0.05). Pooled improvement in LA booster function was 1.96% (95% CI 1.11-2.8, P < 0.01).

Conclusion: TAVR is associated with significant negative LA remodelling, and an improvement in LA mechanics, quantified by STE. The prognostic implications of these findings require further study.