A Randomized Controlled Trial of the Safety and Effectiveness of a Contact Force Sensing Irrigated Catheter for Ablation of Paroxysmal Atrial Fibrillation: Results of the TOCCASTAR Study
Background—Contact Force (CF) is a major determinant of lesion size and transmurality, and has the potential to improve efficacy of atrial fibrillation (AF) ablation. This study sought to evaluate the safety and effectiveness of a novel irrigated radiofrequency ablation (RFA) catheter which measures real-time CF in the treatment of patients with paroxysmal AF.
Methods and Results—A total of 300 patients with symptomatic, drug-refractory, paroxysmal AF were enrolled in a prospective, multicenter, randomized controlled trial and randomized to RFA with either a novel CF sensing catheter or a non-CF catheter (Control). The primary effectiveness endpoint consisted of acute electrical isolation of all pulmonary veins (PVs) and freedom from recurrent symptomatic atrial arrhythmia off all anti-arrhythmic drugs at 12 months. The primary safety endpoint included device-related serious adverse events. Endpoints were powered to show non-inferiority. All PVs were isolated in both groups. Effectiveness was achieved in 67.8% and 69.4% of subjects in the CF and Control arms, respectively (absolute difference -1.6%, lower limit of one-sided 95% CI -10.7%, p=0.0073 for non-inferiority). When the CF arm was stratified into optimal CF (≥90% ablations with ≥10g) and non-optimal CF groups, effectiveness was achieved in 75.9% vs. 58.1%, respectively (p=0.018). The primary safety endpoint occurred in 1.97% and 1.40% of CF patients and Controls, respectively (absolute difference 0.57%, upper limit of one-sided 95% CI 3.61%, p=0.0004 for non-inferiority).
Conclusions—The CF ablation catheter met the primary safety and effectiveness endpoints. Additionally, optimal CF was associated with improved effectiveness.
Clinical Trial Registration Information—clinicaltrials.gov; Identifier: NCT01278953.
- Received November 17, 2014.
- Revision received May 28, 2015.
- Accepted July 6, 2015.