The Impact of Atrial Fibrillation Ablation on Left Atrial Function: Association with Baseline Left Atrial Function

BACKGROUND: The effect of atrial fibrillation (AF) ablation on left atrial (LA) function has not been sufficiently determined. METHODS: We enrolled 115 consecutive patients with paroxysmal or persistent AF that underwent AF ablation. Multidetector computed tomography was performed in sinus rhythm before and 3 months after ablation to evaluate LA volume (LAV) and function. Estimates of maximum and minimum LAV were used to calculate LA emptying fraction (LAEF) ([maximum-minimum LAV]/maximum LAV × 100). RESULTS: AF ablation significantly decreased maximum LAV (59.0 ± 20.4 to 53.3 ± 16.7 cm(3) , P = 0.001), and maintained LAEF (44.5 ± 13.1% to 43.7 ± 10.9%, P = 0.49). The larger the baseline maximum LAV, the greater the decrease in LAV after ablation, and a smaller baseline LAEF was associated with a larger recovery of LAEF after ablation (regression coefficient =-0.45 and -0.56, respectively, P < 0.0001). Multivariable analyses revealed that an impaired baseline LAEF was an independent predictor of an improvement in LA function (an increase in LAEF of >10%; odds ratio [OR] = 0.88, P < 0.0001), while an older age and preserved baseline LAEF were independently associated with a deterioration of LA function (a decrease in LAEF of >10%; OR = 1.06, P = 0.03; and OR = 1.10, P = 0.0001). CONCLUSIONS: AF ablation appears to have a beneficial effect on LA function in patients with impaired LA function at baseline. However, it may reduce LA function in patients with an older age and preserved baseline LAEF.