0029: Does the class of antiarrhythmic drug change the risk of atrial flutter in patients with atrial fibrillation or the risk of atrial fibrillation after atrial flutter ablation?

Atrial fibrillation (AF) and atrial flutter (AFL) are frequently associated. The purpose of the study was to look for the effect of antiarrhythmic drugs (AAD) on the risk of AF occurrence after radiofrequency ablation of AFL. Methods 1121 patients, mean age 64±12 years, were referred for AFL ablation. History, data of echocardiography, antiarrhythmic drug (AAD), were collected. Patients were followed from 3 months to 10 years (mean 2.1±2.7 years). AAD was stopped after ablation except in patients with previous AF before ablation or continued otherwise. Results 857 patients received an AAD (n=637) or a betablocker (n=221). 356 patients (31.7%) had a history of AF prior to AFL ablation. Patients with AF prior to ablation were more likely to be female (OR=1.35, CI=1.00-1.83, p=0.05), more likely to be treated with a class I AAD (45.5% vs 7.7%), isolated or associated with beta-blockers and more likely tended to be treated with Amiodarone (36.5% vs. 31.2%, p=0.08). After ablation, 260 (23.2%) patients experienced AF. In multivariable model, AF prior to ablation (OR=1.90, CI=1.42-2.54, p Conclusions AF occurrence after AFL ablation is frequent (>20%), especially in patients with a history of AF, in female patients, and in patients treated with Class I antiarrhythmics/Amiodarone prior to AFL. The risk was similar in patients treated with class I or III drug. In a patient referred for AFL ablation without known AF before AFL, treated with AAD, the follow-up should be careful because these patients appear at high risk of AF occurrence.