Abstract 15927: Successful Pharmacological Cardioversion by Oral Amiodarone Therapy is Correlated With Favorable Post-Ablation Clinical Outcomes in Non-Paroxysmal Atrial Fibrillation

Abstract

Backgrounds: Catheter ablation (CA) for non-paroxysmal atrial fibrillation (AF)(non-PAF) is less successful in patients (pts) with highly remodeled atria. It is still controversial that how far CA should be indicated in non-PAF pts with highly remodeled atria. Impacts of successful pharmacological cardioversion of non-PAF by oral amiodarone (AMD) on post-CA clinical outcomes remain to be evaluated. Purposes: To assess efficacy of oral AMD and implications of successful cardioversion by AMD in advance to CA on post-CA clinical outcomes in non-PAF pts. Methods: In consecutive 418 non-PAF pts (age: 63±9 years, AF duration: 28±37 months, LA diameter: 44±5mm), oral AMD (300 mg/day for 2 weeks and 100 mg/day thereafter) was initiated at outpatient clinic one month prior to the initial CA procedure. Recurrence-free survival after last CA procedure was compared between those with successful pharmacological conversion to sinus rhythm, atrial flutter or atrial tachycardia by the time of the initial CA procedure (Group non-AF) and those without (Group AF) . Results: At the beginning of initial CA procedure, 79 pts were in sinus rhythm, 8 in typical atrial flutter, 3 in atrial tachycardia (Group non-AF: 90 pts (22%)) and the remaining 328 still in AF (Group AF: 78%) . During follow-up period of 287±204 days after last CA procedure (procedure number:1.6±0.7/pt, range: 1-4), 45 pts (11%) were followed up while taking AMD, whereas the other 373 pts (89%) without any antiarrhythmic drugs. Kaplan-Meier analysis revealed that recurrence-free survival after last CA procedure was significantly higher in Group non-AF than in Group AF (88 (98%) vs. 291 (89%) pts; p=0.02) . Group non-AF pts exhibited significantly shorter AF duration (9±9 (range: 1-46) vs. 33±41 months (range: 1-240): p<0.0001) and smaller LA diameter (42±5 (range: 28-54) vs. 44±5 mm (range: 31-61): p<0.0001) as compared with those in Group AF pts. Conclusions: Successful cardioversion by AMD in advance to CA was correlated with higher recurrence-free survival after last CA procedure. This simple criterion is helpful to find pts with less remodeled atria and good candidates for CA who will benefit from CA in non-PAF pts.