Incidence and risk factors for very late recurrence of atrial fibrillation after radiofrequency catheter ablation.

AIMS: Although several prognostic factors for atrial fibrillation (AF) recurrence after catheter ablation (CA) have been reported, predictors of very late recurrence (VLR; initial recurrence >12 months after ablation) remain unidentified. This study investigated clinical variables predictive of VLR after CA for AF. METHODS AND RESULTS: This retrospective single-centre cohort study evaluated data from 1016 consecutive drug-refractory AF patients who underwent single CA for AF from July 2004 to May 2010. After excluding 324 patients with a short follow-up period (<1 year) and 300 patients with recurrence within a year of CA, 392 patients were included. Study subjects were divided into two groups on the basis of VLR presence. Preoperative clinical variables were evaluated as predictors of VLR using the Cox proportional hazards model. The annual rate of VLR was 7.6% after single CA. Univariate analysis revealed that hypertension [hazard ratio (HR) 1.77, 95% confidence interval (CI) 0.93-3.37, P = 0.08], obesity (HR 1.84, 95% CI 0.98-3.45, P = 0.06), long-standing persistent AF (HR 2.35, 95% CI 1.08-5.11, P = 0.03), and abnormally high preoperative C-reactive protein (CRP) levels >0.5 mg/dL (HR 4.28, 95% CI 2.03-9.03, P < 0.0001) were associated with VLR. In the multivariate model, only abnormally high preoperative CRP level was an independent predictor of VLR (HR 4.9, 95% CI 2.3-10.7, P < 0.0001). CONCLUSION: Even after a year without AF, VLR occurred annually in 7.6% cases. Continued vigilance for VLR after CA is clinically desirable, especially for patients with abnormally high preoperative CRP levels.