Contact force sensing for ablation of persistent atrial fibrillation: A randomized, multicenter trial


BACKGROUND: Impact of contact force sensing (CFS) on ablation of persistent atrial fibrillation (PeAF) is unknown.

OBJECTIVE: The purpose of the TOUCH AF (Therapeutic Outcomes Using Contact force Handling during Ablation of Persistent Atrial Fibrillation) randomized trial was to compare CFS-guided ablation to a CFS-blinded strategy.

METHODS: Patients (n = 128) undergoing first-time ablation for persistent AF were randomized to a CFS-guided vs CFS-blinded strategy. In the CFS-guided procedure, operators visualized real-time force data. In the blinded procedure, force data were hidden. Wide antral pulmonary vein isolation plus a roof line were performed. Patients were followed at 3, 6, 9, and 12 months with clinical visit, ECG, and 48-hour Holter monitoring. The primary endpoint was cumulative radiofrequency (RF) time for all procedures. Atrial arrhythmia >30 seconds after 3 months was a recurrence.

RESULTS: PeAF was continuous for 26 weeks (interquartile range [IQR] 13–52), and left atrial size was 45 ± 5 mm. Force in the CFS-blinded and CFS-guided arms was 12 g [IQR 6–20] and 14 g [IQR 9–20] (P = .10), respectively. Total RF time did not differ between CFS-guided and CFS-blinded groups (49 ± 14 min vs 50 ± 20 min, respectively; P = .70). Single procedure freedom from atrial arrhythmia was 60% in the CFS-guided arm and 63% in the CFS-blinded arm off drugs. Lesions with gaps were associated with significantly less force (11.4 g [IQR 6–19] vs 13.2 g [IQR 8–20], respectively; P = .0007) and less force-time integral (174 gs [IQR 91–330] vs 210 gs [IQR 113–388], respectively; P <.001).

CONCLUSION: CFS-guided ablation resulted in no difference to RF time or 12-month outcome. Lower force/force-time integral was associated with significantly more gaps.

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February 2018 Volume 15, Issue 2, Pages 201–208