The electroanatomical remodelling of the left atrium is related to CHADS ₂/CHA ₂DS ₂VASc score and events of stroke in patients with atrial fibrillation

Background Although atrial fibrillation (AF) increases the risk of stroke, its relationship with atrial remodelling has not yet been studied. We hypothesized that the degree of electroanatomical remodelling of the left atrium (LA) is related to CHADS2/CHA2DS2VASc score and events of stroke. Methods and results We compared CHADS2/CHA2DS2VASc score (0, 1, ≥2) or events of stroke with mean and regional LA volume [by three-dimensional (3D) computed tomography images] or LA endocardial voltage (by 3D-electroanatomical map) in 348 patients who underwent catheter ablation of AF (78.4 male, 55.4±11.0 years old, paroxysmal AF:persistent AF 215:133). We graded LA volume index as Grade 1 (<48.3 mL/m ²; n = 80), grade 2 (48.3-63.0 mL/m ², n = 82), grade 3 (63.0-99.0 mL/m ²; n = 94), and grade 4 (≥99.0 mL/m ²; n [ 92). Results (i) The percentage volume of anterior portion of LA enlarged at the early stage of LA remodelling (Grade 1 vs. grade 2, P = 0.006) and the voltage of posterior venous LA was significantly reduced with the degree of LA remodelling (P = 0.001). (ii) Mean LA volume/body surface area (BSA), especially anterior portion of LA, was greater in patients with high CHADS2/CHA2DS2VASc score (P = 0.002). Mean LA voltage was significantly lower in patients with high CHA2DS2VASc score than low score (P = 0.007). (iii) In patients who experience stroke (n = 22), LA volume/BSA, especially anterior LA, was greater (P = 0.012), and LA endocardial voltage was lower (P = 0.039) than those without stroke. Conclusion Electroanatomical remodelling of LA, estimated by LA volume and endocardial voltage, has significant relationship with the risk scores or events of stroke in patients with non-valvular AF.