Improved left atrial function in CRT responders: A systematic review and meta-analysis

Abstract

Cardiac resynchronization therapy (CRT) is associated with reverse left atrial (LA) remodeling. The aim of this meta‐analysis was to assess the relationship between clinical response to CRT and LA function changes. We conducted a systematic search of all electronic databases up to September 2019 which identified 488 patients from seven studies. At (mean) 6 months follow-up, LA systolic strain and emptying fraction (EF) were increased in CRT responders, with a –5.70% weighted mean difference (WMD) [95% confidence interval (CI) –8.37 to –3.04, p < 0.001 and a WMD of –8.98% [CI –15.1 to –2.84, p = 0.004], compared to non-responders. The increase in LA strain was associated with a fall in left ventricle (LV) end-systolic volume (LVESV) r = –0.56 (CI –0.68 to –0.40, p < 0.001) and an increase in the LV ejection fraction (LVEF) r = 0.58 (CI 0.42 to 0.69, p < 0.001). The increase in LA EF correlated with the fall in LVESV r = –0.51 (CI –0.63 to –0.36, p < 0.001) and the increase in the LVEF r = 0.48 (CI 0.33 to 0.61, p = 0.002). The increase in LA strain correlated with the increase in the LA EF, r = 0.57 (CI 0.43 to 0.70, p < 0.001). Thus, the improvement of LA function in CRT responders reflects LA reverse remodeling and is related to its ventricular counterpart.