Impact of ablation catheter irrigation design on silent cerebral embolism after radiofrequency catheter ablation of atrial fibrillation: results from a pilot study.

Introduction: Silent cerebral lesions (SCL) are a sensitive tool to evaluate thromboembolic risk of catheter ablation. Recent data showed the possibility to reduce thrombus formation when the electrode-tissue interface cooling is optimized by a homogeneous flushing of saline along the entire surface of the distal electrode through a larger number of irrigation holes. The study aim is to compare procedural parameters and safety of pulmonary vein isolation (PVI) performed by using open-irrigated catheters with different irrigation design.

Methods And Results: Eighty patients (74% males; age 57 ± 12 years) with paroxysmal AF randomly underwent PVI performed with a new irrigation design catheter (group A, 40 patients) versus a standard irrigated catheter (group B, 40 patients). A cerebral magnetic resonance imaging (MRI) was performed before and after the procedure. Postprocedural brain MRI unveiled SCL in 2 patients in group A and in 3 in group B (5% vs 7.5%, P = 0.500). Intraprocedural ACT was the only independent factor associated with the occurrence of SCL (OR = 0.996; 95% CI 0.994-0.998, P < 0.001). Among procedural parameters, we observed a reduction of irrigation saline volume of 662 mL in group A versus group B (P < 0.001).

Conclusion: PVI performed with a new irrigated catheter did not reduce significantly the SCL risk when compared to a standard irrigated catheter. Intraprocedural ACT reduces the SCL risk of 0.4% for each point of ACT increase. For ACT > 320 seconds no SCL occurred. Finally, compared to a standard irrigated catheter, PVI performed with a new irrigation design catheter reduces significantly saline volume infusion.