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

BackgroundThe CHADS2 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).ObjectiveThis study aimed to investigate the associations between the CHADS2 score, atrial substrate, and outcome of catheter ablation in patients with paroxysmal AF.MethodsA total of 247 paroxysmal AF patients who received catheter ablation were enrolled. The patients were divided into 3 groups according to their CHADS2 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.ResultsThe CHADS2 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 CHADS2 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 CHADS2 scores remained as the independent predictor of recurrence in the multivariate analysis.ConclusionA high CHADS2 score was associated with different left atrial substrate properties and a poor outcome after catheter ablation of paroxysmal AF.