Development and validation of a risk score for predicting atrial fibrillation recurrence after a first catheter ablation procedure - ATLAS score

Aims Several predictors of relapse after catheter ablation of atrial fibrillation (AF) have been established, but assessing each patient's individual risk remains challenging. Our aim was to develop and validate a score to estimate the risk of AF recurrence after the first radiofrequency pulmonary vein isolation (PVI) procedure. Methods and results Independent predictors of AF relapse were identified retrospectively in a two-centre registry of 1934 patients who underwent a first PVI procedure. Using the Cox regression hazard ratios of designated variables, a risk score was developed in a random sample of 50% of the patients (development cohort) and validated in the remaining (validation cohort) half. The accuracy and discriminative power of the predictive model were assessed in both subgroups. During a follow-up of 4.2 +/- 2.7 years, 522 patients (27%) relapsed. Five independent predictors of AF recurrence were identified and included in the score: age > 60 years (1 point), female sex (4 points), non-paroxysmal AF (2 points), current smoking (7 points) and indexed left atrial volume (1 point for each 10 mL/m(2)). The score showed good discriminative power (censored c-statistic of 0.75 in both cohorts). In the development group, AF relapse rates were 8, 11, and 17%/year for low (< 6 points), intermediate (6-10 points), and high-risk patients (> 10 points), respectively (P < 0.001). In the validation group, AF recurrence rates were 8, 11, and 18%/year, respectively (P < 0.001). Conclusion A simple risk score to estimate the rate of AF recurrence after ablation was developed and validated. An external assessment of its usefulness as a patient selection tool seems warranted.