Associations among the CHADS2 score, atrial substrate properties, and outcome of catheter ablation in patients with paroxysmal atrial fibrillation

Background The CHADS 2 score (congestive heart failure, hypertension, age >75 years, diabetes, and previous stroke/transient ischemic attack) is used for the risk stratification of strokes in patients with atrial fibrillation (AF). Objective This study aimed to investigate the associations between the CHADS 2 score, atrial substrate, and outcome of catheter ablation in patients with paroxysmal AF. Methods A total of 247 paroxysmal AF patients who received catheter ablation were enrolled. The patients were divided into 3 groups according to their CHADS 2 score (group 1: score 0, group 2: score 1 to 2, and group 3: score 3 to 6). The bi-atrial substrate properties and outcome of catheter ablation were analyzed. Results The CHADS 2 scores in these 3 groups were 0 (group 1), 1.24 ± 0.48 (group 2), and 3.60 ± 0.83 (group 3), respectively. The left atrial voltage became lower (group 1 vs. 2 vs. 3=2.08 ± 0.73 mV vs. 1.80 ± 0.81 mV vs. 1.06 ± 0.69 mV) and the activation time longer (group 1 vs. 2 vs. 3=93.4 ± 17.7 ms vs. 101.9 ± 21.2 ms vs. 112.2 ± 21.7 ms), whereas the CHADS 2 score increased. During a follow-up of 17.3 ± 7.0 months, 23.1% of the study population suffered from recurrences. The recurrence rates of these 3 groups were 13.0% (group 1), 27.6% (group 2), and 45.9% (group 3), respectively. The groups of different CHADS 2 scores remained as the independent predictor of recurrence in the multivariate analysis. Conclusion A high CHADS 2 score was associated with different left atrial substrate properties and a poor outcome after catheter ablation of paroxysmal AF.