August 1, 2014Open Access
View Full PaperParoxysmal AF Catheter Ablation With a Contact Force Sensing Catheter
Key Result
Catheter ablation with an irrigated contact force-sensing catheter achieved 72.5% 12-month freedom from arrhythmia recurrence (OR 4.25 for success when contact force was in target ≥80% of the time).
Study Design
Type
Observational (n=172)
Multicenter
Yes
Structured PICO
Does catheter ablation with an irrigated contact force-sensing catheter improve freedom from arrhythmia recurrence in patients with drug-refractory symptomatic paroxysmal atrial fibrillation?
P
Population
172 patients with drug refractory symptomatic paroxysmal atrial fibrillation (≥3 symptomatic episodes within 6 months and failure of ≥1 Class I-IV antiarrhythmic drug)
I
Intervention
Pulmonary vein isolation using an irrigated, contact force-sensing catheter (THERMOCOOL SMARTTOUCH)
O
Outcome
Procedural-related serious adverse events within 7 days and 12-month freedom from atrial fibrillation/atrial flutter/atrial tachycardia recurrence
Catheter ablation using a contact force-sensing catheter is effective for paroxysmal AF, and maintaining stable contact force within targeted ranges significantly improves 12-month procedural success.
Main Result
Effect estimate: OR 4.25 (95% CI 1.53-11.79)
p-value: p=0.0054
Abstract
BACKGROUND: Catheter ablation is important for treatment of paroxysmal atrial fibrillation (PAF). Limited animal and human studies suggest a correlation between electrode-tissue contact and radiofrequency lesion generation. OBJECTIVES: The study sought to assess the safety and effectiveness of an irrigated, contact force (CF)-sensing catheter in the treatment of drug refractory symptomatic PAF. METHODS: A prospective, multicenter, nonrandomized study was conducted. Enrollment criteria included: ≥3 symptomatic episodes of PAF within 6 months of enrollment and failure of ≥1 antiarrhythmic drug (Class I to IV). Ablation included pulmonary vein isolation with confirmed entrance block as procedural endpoint. RESULTS: A total of 172 patients were enrolled at 21 sites, where 161 patients had a study catheter inserted and 160 patients underwent radiofrequency application. Procedural-related serious adverse events occurring within 7 days of the procedure included tamponade (n = 4), pericarditis (n = 3), heart block (n = 1, prior to radiofrequency application), and vascular access complications (n = 4). By Kaplan-Meier analyses, 12-month freedom from atrial fibrillation/atrial flutter/atrial tachycardia recurrence was 72.5%. The average CF per procedure was 17.9 ± 9.4 g. When the CF employed was between investigator selected working ranges ≥80% of the time during therapy, outcomes were 4.25 times more likely to be successful (p = 0.0054; 95% confidence interval: 1.53 to 11.79). CONCLUSIONS: The SMART-AF trial demonstrated that this irrigated CF-sensing catheter is safe and effective for the treatment of drug refractory symptomatic PAF, with no unanticipated device-related adverse events. The increased percent of time within investigator-targeted CF ranges correlates with increased freedom from arrhythmia recurrence. Stable CF during radiofrequency application increases the likelihood of 12-month success. (THERMOCOOL® SMARTTOUCH® Catheter for Treatment of Symptomatic Paroxysmal Atrial Fibrillation; NCT01385202).