P3604High cerebrovascular thromboembolic rate after unsuccessful catheter ablation for atrial fibrillation

Abstract

Background: Atrial fibrillation (AF) is the most common supraventricular arrhythmia in clinical practice and it is associated with a significant number of stroke and decreased quality of life. Catheter ablation (CA) has become a therapeutic option for patients with drug-resistant AF. Randomized clinical trials have demonstrated the superiority of CA of AF as compared with pharmacological treatment. The majority of studies focusing on clinical outcome, success-and recurrence rates with long-term follow-up (FU) of AF patients who had successful rhythm control by means of CA. No data is available concerning the long-term stroke rate of pts underwent unsuccessful CA of AF. Purpose(s): The aim of the current study was to detect the long-term thromboembolic complication rate of patients with unsuccessful CA of AF and to compare it with the outcome of a control group with successful ablation. Method(s): 1002 patients underwent CA, and among those procedures 169 were declared as failures due to a documented episode of AF after a blanking period. From the latter group 67 patients fulfilled the inclusion criteria of having completed 5 year of FU [N=45 male; 65.7 years old (SD: 10.3); left atrial size=45 mm (SD: 6.3); with an 11.7 years of AF history (SD: 8)]. 498 pts fulfilled the 5-year FU out of 833 pts in successful group [N=317, left atrial size=43.9 (SD: 13.12)]. Result(s): No death was registered during the FU period among the patients included in this study. Thirty-one patients underwent a cardiovascular electronic device implantation, and 20 patients in the unsuccessful group also had CA of His-bundle afterwards (29.8%). The average number of CA procedures for AF per patient was 1.7+/-0.8 (22 patients underwent 2 attempts and 13 patients had 3 procedures). Thirty-seven patients (55.2%) had a cryoballoon ablation as first procedure, all the others underwent radiofrequency CA. In addition, 8 patients underwent a VATS-Maze procedure afterwards, and 17 patients had cavotricuspid isthmus ablation. Eighteen patients (27%) suffered an ischemic stroke in the FU period under sufficient oral anticoagulation, while only 8 of them had had a stroke before the first attempt of CA (one patient had an ischemic stroke before and after a CA). Average time between the stroke and the CA procedure was 3.9 years (SD: 3.3). In the successful ablation group no patients had His-bundle ablation or VATS-Maze procedure, however 9 pts underwent Pm implantation. The average number of CA was 1+/-0.34 (11 patients had 2 attempts, while 2 patients had 3 attempts). We found significantly lower occurrence rate (p<0, 01) of transient ischemic attack in 5 out of 498 pts (1%), with an average occurrence period of 3.6 years after CA. Conclusion(s): The risk of stroke is high among patients after unsuccessful catheter ablation of atrial fibrillation compared to those after successful ablation. The underlying possible causes require further investigations.