Cerebral Embolism (CE) in Catheter Ablation of Atrial Fibrillation (AF)

Overview

Radiofrequency catheter ablation of atrial fibrillation (AF) induces a procoagulant state, which leads to an acute risk for symptomatic cerebral embolism (CE) of approximately 1%. The induction of a procoagulant state has been studied in pulmonary vein isolation (PVI) with a non-cooled tip catheter. The induction of a procoagulant state using a cooled-tip catheter has not been studied yet. Due to the avoidance of high endocardial temperatures, it can be expected that these procedures induce a lower level of procoagulation. Recent studies showed an 11% incidence of CE on diffusion weighted (DW) MRI in patients undergoing cooled-tip catheter ablation of AF. In this study there will be used to different catheters, the cooled-tip catheter and the PVAC Gold catheter. Since the PVAC Gold catheter is equipped with non-cooled electrodes, the risk of endothelial scarring, local thrombosis and CE may be increased. The goal of this study is to determine the effect of two different ablation catheters on the induction of a procoagulant state and the incidence of CE on DW-MRI in patients with AF undergoing PVI. Our hypothesis is that patients with AF undergoing PVI using the PVAC gold catheter will show a higher rise in procoagulation and a higher incidence of CE on DW-MRI than patients with AF undergoing PVI with the cooled-tip catheter.

A total of 70 patients scheduled for a first ablation of paroxysmal AF will be included. Patients will be 1:1 randomized to PVI using the PVAC gold catheter or the cooled-tip catheter. A control group of 20 patients with AF but without undergoing ablation is included for neuropsychological testing. Before the procedure, the procoagulant state will be assessed by measuring several markers of endothelial damage, activated coagulation, fibrinolysis and by measurement of fibrinogen and thrombin generation. Measurements will be repeated during and after the procedure. Documentation of the formation of CE will be established by performing a DW-MRI before and after the ablation. The proportion of symptomatic CE will be quantified by neuropsychological tests and questionnaires. Finally, transcranial doppler will be performed during the entire procedure to quantify the number and pattern of cerebral microembolic signals (MES).