Incidence and Clinical Significance ofCerebral Embolism During AtrialFibrillation Ablation With Duty-Cycled Phased-Radiofrequency Versus Cooled-Radiofrequency: A Randomized Controlled Trial.

Abstract

The purpose of this study was to randomly compare the incidence of asymptomatic cerebral embolism (ACE) between the second-generation pulmonary vein ablation catheter (PVAC Gold) and the irrigated Thermocool catheter. Pulmonary vein isolation (PVI) with the PVAC is associated with ACE. The PVAC Gold was designed to avoid this complication. Patients with paroxysmal atrial fibrillation were randomized 1:1 to PVI with the PVAC Gold or Thermocool catheter. Cerebral magnetic resonance imaging was performed in the days before and after ablation and repeated after 3 months in case of a new lesion. Monitoring for microembolic signals (MES) was performed by using transcranial Doppler ultrasonography. Parameters of coagulation were determined before, during, and after ablation. Neuropsychological tests and questionnaires were applied 10 days before and 3 months after ablation. Seventy patients were included in the study (mean age 61 ± 9 years; 43 male subjects; CHA2DS2-VASc [congestive heart failure, hypertension, age≥75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65 to 74 years, sex category] score 1.6 ± 1.2; international normalized ratio 2.7 ± 0.5; activated clotting time 374 ± 24 s; p > 0.05 for all parameters). Procedural duration was shorter in the PVAC Gold group (140 ± 34 vs. 207 ± 44 min; p< 0.001). Eight (23%; 7 infarcts) patients in the PVAC Gold group exhibited a new ACE, compared with 2 (6%; no infarcts) patients in the Thermocool group (p= 0.042). Median number of MES was higher in the PVAC Gold group (1,111 [interquartile range, 715-2,234] vs. 787 [interquartile range, 532-1,053]; p< 0.001). There were no differences between groups regarding coagulation and neuropsychological outcomes. PVI with the new PVAC Gold was associated with a higher incidence of ACE/cerebral infarcts and number of MES. Both catheters induced a comparable procoagulant state. Because there were no measurable differences in neuropsychological status, the clinical significance of ACE remains unclear. (Cerebral Embolism [CE] in Catheter Ablationof Atrial Fibrillation [AF] [CE-AF]; NCT01361295).