Predictors, management, and outcome of cardioversion failure early after atrial fibrillation ablation

Aims: Electrical cardioversion (ECV) is frequently required for early atrial fibrillation (AF) recurrence after catheter ablation. However, in some cases, ECV is unsuccessful, and factors associated with long-term rhythm outcomes after failed ECV are unknown. This study aimed to identify possible predictors of ECV failure early after AF ablation and to analyse management and long-term rhythm outcome of these patients. Methods and results: Between 2010 and 2012, 180 consecutive patients (mean age 63.7 ± 9.4 years, male 53.3%, persistent AF 60%) underwent successful radiofrequency AF ablation but required post-procedural ECV due to early AF recurrence (≤ 7 days). Of these, 120 patients were successful (Group A, n = 120, 66.7%) and 60 failed (Group B, n = 60, 33.3%). ECV failure was associated with diabetes [odds ratio (OR) 2.34, 95% confidence interval (CI) 1.154-4.763; P = 0.01] and lack of beta-blocker medication (OR 2.38, 95% CI 1.005-5.635; P = 0.04). In contrast, there were no significant differences in echocardiographic or procedure-related parameters. Atrial fibrillation recurrence was monitored with sequential 7 days of Holter electrocardiogram for 24 months (on average 10.8 ± 8.8 months) and was documented in 56%, n = 102 in total (Group A: 57%, n = 69 vs. Group B: 55%, n = 33; P = 0.75). Compared with successful ECV, ECV failure shortly after AF ablation had no predictive value on rhythm outcome in the long term (P = 0.98). The necessity of additional linear lesions during catheter ablation [hazard ratio (HR) 2.72, 95% CI 1.47-5.05; P = 0.001], AF duration (HR 1.08, 95% CI 1.04-1.12; P < 0.001), and a prolonged ablation time (HR 3.27, 95% CI 1.53-6.97; P = 0.002) were associated with long-term AF recurrence. Conclusion: Patients with diabetes and absence of beta-blocker medication are at higher risk for ECV failure. Early post-ablation ECV failure is not associated with long-term rhythm outcome.