Effect of preventing air intrusion on silent strokes during atrial fibrillation ablation using a mini‐basket catheter.

Background: Air bubble intrusion through transseptal sheaths during left atrial (LA) catheter ablation can cause cerebral embolisms, especially when using complex‐shape catheters. This study aimed to compare the incidence of silent cerebral events (SCEs) after atrial fibrillation (AF) catheter ablation using a mini‐basket catheter (IntellaMap Orion; Boston Scientific) between the following groups: group SP, strict prevention of LA air intrusion and group CP, conventional air intrusion prevention. Methods: We enrolled 123 consecutive AF patients (group SP, n = 61 and group CP, n = 62) who underwent brain magnetic resonance imaging after a local‐impedance‐guided ablation using one mini‐basket catheter and one circular mapping catheter. The preventive strategy in group SP included (a) the insertion of the mini‐basket catheter into the transseptal sheaths in a container filled with heparinized saline and (b) no exchange of all catheters over the sheaths. Results: SCEs were detected in 67 patients (54.5%), and the incidence of SCEs did not significantly differ between groups SP and CP (55.7% vs 53.2%; P =.780). A multivariate analysis demonstrated that an older age, non‐paroxysmal AF, and radiofrequency (RF) power output were independent positive predictors of SCEs (odds ratios: 1.079, 5.613, and 1.405; P =.005, <.001, and.012). On the follow‐up MR imaging, 83.5% of the SCEs in group SP and 87.7% in group CP disappeared (P =.398). Conclusions: Strict prevention of LA air intrusion may have no additional effect for reducing the incidence of SCEs after local impedance‐guided AF ablation using a mini‐basket catheter. An older age, non‐paroxysmal AF, and high‐power RF applications may increase the risk of SCEs. [ABSTRACT FROM AUTHOR]