CONVERSION TO SINUS RHYTHM WITH IBUTILIDE DURING ATRIAL FIBRILLATION ABLATION IS NOT ASSOCIATED WITH LONG TERM SINUS RHYTHM MAINTENANCE

Abstract

Identifying patients at higher risk of AF recurrence after successful ablation would help with selection of patients for more frequent post-ablation surveillance, more accurate individualized patient prognosis and decision regarding future management options such as anti-coagulation therapy. In patients who remain in AF after ablation, ibutilide is frequently used for restoration of sinus rhythm. In cases of failure to achieve SR with ibutilide, DCCV is used. We hypothesized that termination of AF with ibutilide defines a group of patients with a better long-term outcome. This is a retrospective observational study of 92 AF ablation procedures with drug-refractory symptomatic AF who were followed for a year by routine clinic visits in 3-6 month intervals or earlier in symptomatic patients. Recurrence and timing of atrial fibrillation during follow-up period was documented and compared among 3 groups of patients according to their response to ablation and administration of ibutilide at the time of ablation: spontaneous conversion to SR (SR group), SR conversion with ibutilide (IBU group) and those who required DCCV after ibutilide failure (IBU-DCCV group). The presence of paroxysmal AF (ORcrude=6.42, 95% CI 1.63-25.3, P=0.0079), absence of diabetes (ORcrude=5.60, 95% CI 1.15-27.26, P=0.03) and lower BMI (ORcrude=0.93, 95% CI 0.87-0.99, P=0.02, for 1 kg/m2 increase in BMI) were individually associated with spontaneous cardioversion after ablation. The median time to recurrence of AT/AF (time to failure) for SR, IBU and IBU-DCCV groups were 211, 162.9 and 83 days respectively. The survival curves for the groups were not statistically different (P=0.22) even after adjustment for potential confounders (Figure 1). Duration of RF ablation (HRCrude=1.014, 95% CI 1.001-1.027, P=0.034) and the time since AF diagnosis (HRCrude=1.117, 95% CI 1.046-1.193, P=0.001) were the only baseline parameters associated with AF recurrence after ablation. Conversion to SR with ibutilide is not associated with long-term rhythm maintenance after AF ablation. None of the baseline clinical or procedural parameters predicted the likelihood of successful cardioversion with ibutilide after AF ablation.