New observations from the Second Worldwide Survey on AF Ablation showed that more procedures are being offered every year. Data presented by Riccardo Cappato, Institute Policlinics San Donato, Milan, Italy, at the Boston AF Symposium, showed that more patients with persistent and long-lasting AF are being treated with catheter ablation. However, ablation for paroxysmal atrial fibrillation is offered twice as often as for persistent AF and eight times as often as for permanent AF.
“Ablation in patients with paroxysmal AF is more successful than in previous years and more successful than in patients with persistent and permanent AF,” Cappato told delegates.
The purpose of the First and the Second Worldwide Surveys was to investigate on a large scale the methods, efficacy, and safety of catheter ablation for AF. The first survey was performed in 90 centres, with 8,745 patients and 12,830 procedures. The second study had almost double the number of patients (16,309) and covered 20,825 procedures performed in 85 centres. The method was retrospective analysis and voluntary report through a detailed questionnaire with 48 questions and specific instructions of fulfilment sent to the centres.
Of the 16,309 patients with complete outcomes data after catheter ablation, 70% became asymptomatic without the use of anti-arrhythmic drugs. In the First Survey, the success rate was 52%. The overall success rate (freedom from AF with or without the use of antiarrhythmic drugs) was similar in both surveys, at 80%.
Cappato also said that the Second Survey indicates that ablation using irrigated-tip electrode is as successful as when using 4mm tip electrode, ablation guided by 3D imaging is as successful as when using lasso mapping, and efficacy of ablation increases linearly with experience.
Tamponade was a major complication in 1.31% of the patients in the second survey – the one with higher incidence (213). Cappato highlighted the importance of keeping an eye on the possibility of a delayed tamponade, which is an unreported complication in patients undergoing catheter ablation of AF and occurs in two out of 1,000 procedures. “Delayed tamponade can be caused by multiple trans-septal punctures, multiple RF applications, or intense intra- and post-procedural anticoagulation,” he said. Time delay varies from a few hours to up to 30 hours. It may lead to death in about 10% of the cases. It can be treated with pericardiocentesis.
Cappato said that, with the survey patient-based database, will be possible to conduct sub-analysis on type of AF, associated comorbidity, clinical and strategy-related predictors of outcome, dimensions of left atrium or left ventricle, left ventricular function, time duration of procedure, and cumulative delivered power.