The APPLE score: a novel and simple score for the prediction of rhythm outcomes after catheter ablation of atrial fibrillation.

Abstract

Recurrent atrial fibrillation (AF) occurs in up to 50% of patients within 1year after catheter ablation, and a clinical risk score to predict recurrence remains a critical unmet need. The aim of this study was to (1) develop a simple score for the prediction of rhythm outcome following catheter ablation; (2) compare it with the CHADS2 and CHA2DS2-VASc scores, and (3) validate it in an external cohort. Rhythm outcome between 3 and 12months after AF catheter ablation were documented. The APPLE score [one point for age >65years, persistent AF, impaired eGFR (<60ml/min/1.73m(2)), LA diameter ≥43mm, EF<50%] was associated with AF recurrence and was validated in an external cohort in 261 patients with comparable ablation and follow-up. In 1145 patients (60±10years, 65% male, 62% paroxysmal AF) the APPLE score showed better prediction of AF recurrences (AUC 0.634, 95% CI 0.600-0.668, p<0.001) than CHADS2 (AUC 0.538) and CHA2DS2-VASc (AUC 0.542). Compared to patients with an APPLE score of 0, the odds ratio for AF recurrences was 1.73, 2.79 and 4.70 for APPLE scores 1, 2, or ≥3, respectively (all p<0.05). In the external validation cohort, the APPLE score showed similar results (AUC 0.624, 95% CI 0.562-0.687, p<0.001). The novel APPLE score is superior to the CHADS2 and CHA2DS2-VASc scores for prediction of rhythm outcome after catheter ablation. It holds promise as a useful tool to identify patients with low, intermediate, and high risk for AF recurrence.