Paroxysmal AF Catheter Ablation With a Contact Force Sensing Catheter: Results of the Prospective, Multicenter SMART-AF Trial

Study Questions:

How useful is a contact force (CF)-sensing radiofrequency (RF) ablation catheter for treating patients with paroxysmal atrial fibrillation (AF)?


Twenty-one centers participated in this prospective, nonrandomized study. Circumferential pulmonary vein (PV) isolation was performed using an irrigated, CF-sensing catheter in 160 patients (mean age 58 years) with symptomatic paroxysmal AF. Additional atrial ablation was at the discretion of the operator. One or two redo procedures were allowed in the first 90 days after the index procedure. Serial clinic visits and transtelephonic monitoring were performed during 12 months of follow-up.


Freedom from symptomatic and asymptomatic atrial tachyarrhythmias at 12 months was 69.9%. The mean CF was 17.9 g. A majority of operators used a target CF range between 5 g and 40 g. RF applications were within the desired CF ranges 73% of the time. Freedom from atrial tachyarrhythmias at 12 months was significantly higher when the CF during a procedure was within the desired CF range ≥80% of the time than when it was not (81% vs. 66%). Major complications consisted of tamponade (2.5%), pericarditis (1.8%), and vascular complications (2.5%). The mean CF did not correlate with procedure-related complications.


The authors concluded that the success rate of RF catheter for paroxysmal AF is improved by monitoring CF and maintaining the CF during ablation within the desired range.


A major limitation of RF catheter ablation to isolate the PVs has been a high recurrence rate of PV conduction. A durable lesion requires adequate and stable CF during delivery of RF energy, and the CF-sensing catheter provides valuable immediate feedback that facilitates the creation of adequate lesions.

Clinical Topics: Arrhythmias and Clinical EP, Pericardial Disease, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Pulmonary Veins, Pericarditis, Catheter Ablation, Atrial Flutter, Tachycardia

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