Clinical relevance of the blanking period on late recurrence after catheter ablation of atrial fibrillation

Abstract

Introduction Recurrence of atrial fibrillation (AF) within the blanking period after catheter ablation (CA) is traditionally classified as a transient and benign event. However, recent findings suggest that early recurrence (ER) is associated with late recurrence (LR), challenging the predefined “blanking period”. We aimed to determine the clinical and procedural predictors of ER and LR after CA and establish the risk of LR in patients who experience ER. Methods and Results Retrospective single‐centre study including all patients who underwent a first procedure of AF CA between 2017 and 2019. ER was defined as any recurrence of AF, atrial flutter or atrial tachycardia >30 s within 90 days after CA and LR as any recurrence after 90 days of CA. A total of 399 patients were included, 37% women, median age of 58 years [49‐66] and 77% had paroxysmal AF. Median follow‐up was 33 months (from 13 to 61). ER after CA was present in 14% of the patients, and LR was reported in 32%. Among patients who experienced ER, 84% also had LR (p < .001). Patients with ER had a higher prevalence of moderate/severe valvular heart disease, persistent AF, previous electrical cardioversion, a larger left atrium, higher coronary artery calcium score, and higher rates of intraprocedural electrical cardioversion and cardiac fibrosis on eletroanatomical mapping compared with patients without ER. After covariate adjustment, ER and female sex were defined as independent predictors of LR (hazard ratio [HR] 4.69; 95% confidence interval [CI], 2.99–7.35; p < .001 and HR 2.73; 95% CI, 1.47–5.10; p = .002, respectively). Conclusion The risk of LR after an index procedure of CA was significantly higher in patients with ER (five‐fold increased risk). These results support the imperative need to clarify the clinical role of the blanking period.

Reconsideration of the definition of blanking period and significance of early recurrences after catheter ablation of atrial fibrillation

“…Recent studies have demonstrated the relationship between ERAT and LR, particularly in the case of ERAT >4 weeks after the index procedure. In a single center study, Silva et al [10] observed that ERAT was present in 14% of patients undergoing radiofrequency or cryoablation of AF. Among patients who experienced ERAT, 84% also had LR.…”