Atrial fibrillation redo ablation procedure: impact of the ablation strategy on the occurrence of arrhythmias' recurrences.
G Annoni, E Chieffo, V Buia, S Savastano, A Sanzo, A Vicentini, E Baldi, B Petracci, M Foti, L Vitali Serdoz, C Carrozzi, S D'amore, D Bastian, R RordorfAbstract
Background
catheter ablation by means of pulmonary vein (PV) isolation is the cornerstone treatment of atrial fibrillation (AF); nevertheless, AF ablation carries a non-negligible rate of arrhythmic recurrences after a first procedure. Several observational studies have shown that repeat ablation (redo) are associated with a lower incidence of arrhythmic recurrences during follow-up compared with medical therapy alone. Despite this evidence, a standardized approach to redo procedures is still lacking.
Purpose
the aim of our study was to evaluate the incidence of arrhythmic recurrences after AF redo ablation according to the adopted procedural strategy.
Methods
in this retrospective, observational, multicenter study, we enrolled consecutive patients undergoing a first redo AF ablation. The primary outcome was the occurrence of documented AF recurrence lasting more than 30 seconds. The population was divided into three groups according to the procedural strategy, and the hazard ratio (HR) with 95% confidence interval (CI) was calculated for each group using the Cox proportional hazards model.
Results
a total of 99 patients were included (17% female, median age 62; 53% paroxysmal AF, 33% structural heart disease). Most patients (71%) had left atrial dilation, and the median left ventricular ejection fraction was 58% (54–60). At the time of redo, 78 patients (78%) showed at least one pulmonary vein reconnection (PVR). Thirty-two underwent only PV re-isolation (group 1), 46 underwent PV re-isolation plus additional ablation targets (posterior wall isolation 46%, mitral isthmus ablation 6.5%, pulmonary vein carena and ridge between the left appendage and pulmonary veins ablation 13%, others 34.5%) (group 2), and 21 underwent ablation of non PV-targets because of persistent PV isolation (group 3). The energy used during redo was 85% radiofrequency, 12% pulsed field ablation and 2% dual energy. After a median follow up of 15 months 57 patients (57%) experienced arrhythmic recurrence: the rate of arrhythmic recurrences was similar across the 3 groups (66% in group 1, 50% in group 2, and 53% in group 3 - see Figure 1). When patients who were treated with posterior wall isolation (n= 33, 33%) were analyzed separately no significant reduction in arrhythmic recurrences was found. Both in-hospital recurrences and those occurring during the blanking period (3 months post procedure) were significantly associated with an increased risk of arrhythmic recurrence at follow-up (HR 2.9, 95% CI 1.29–6.52; P = 0.01 and HR 2.4, 95% CI 1.4–4.41; P = 0.001, respectively) (Figure 2).
Conclusions
in patients undergoing AF redo ablation, no procedural approach demonstrated superiority in preventing arrhythmic recurrence. Conversely, early recurrences—whether during hospitalization or within the blanking period—were powerful predictors of late relapse, highlighting their prognostic value and challenging the notion that such events are merely transient.Figure 1Figure 2