Influence of PACE Score and Conduction Disturbances in the Incidence of Early New Onset Atrial Fibrillation after Typical Atrial Flutter Ablation.

Purpose: Patients undergoing cavotricuspid isthmus (CTI) ablation for typical flutter (AFL) have a high incidence of new onset atrial fibrillation (AF). We aimed to analyze the influence of PACE score to predict new onset AF in this subset of patients to stratify thromboembolic risk. Methods: Between 2017 and 2019, patients undergoing CTI ablation for AFL and without history of AF were prospectively included. All patients were monitored continuously by implantable loop recorder and followed by remote monitoring. Results: Overall 48 patients were included. New onset AF rate at 12 months was 56.3%. We observed two very strong independent predictors for new onset AF: a PACE score > 30 (HR:6.9; 95% CI:1.71-27.91; p = 0.007) and an HV interval > 55 (HR:11.86; 95% CI:2.57-54.8; p = 0.002). Conclusions: The incidence of newly diagnosed AF is high in patients with AFL after CTI ablation, and can occur early. A high PACE score and/or long HV interval predict even higher risk, and may be useful in the decision for empiric long-term anticoagulation.