Silent Cerebral Embolism During Catheter Ablation of Atrial Fibrillation

Radiofrequency catheter ablation is recommended with increasing frequency as part of a treatment regimen for both paroxysmal and persistent forms of symptomatic atrial fibrillation (AF), largely because of the relatively poor efficacy of antiarrhythmic medications1 and trials showing improvement in quality of life and reduction in AF in selected patients.2 The ongoing Catheter Ablation Versus Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial is a randomized, multicenter study currently enrolling up to 3000 patients to test whether a treatment strategy of left atrial catheter ablation for the purpose of eliminating AF will be superior to current medical therapy for reducing total mortality in patients with AF.3 For catheter ablation to be superior, procedural complications need to be minimized.Article see p 1667Catheter ablation for AF is infrequently associated with clinically apparent thromboembolism. Cappato et al4 reported a 0.94% incidence of stroke or transient ischemic attack in a worldwide survey of AF ablation, and Scherr et al5 reported a 1.4% incidence overall with a higher incidence in patients with CHADS2 score ≥2 or prior transient ischemic attack. In a study at the Brigham and Women's Hospital, we observed a 0.7% incidence of stroke or transient ischemic attack.6 It is important to recognize that the incidence of asymptomatic embolic events may …