A randomized trial of contact force in atrial flutter ablation.

AIMS: Contact force (CF) sensing has emerged as a tool to guide and improve outcomes for catheter ablation (CA) for cardiac arrhythmias. The clinical benefit on patient outcomes remains unknown. To study whether CF-guided CA for typical atrial flutter (AFL) is superior to CA not guided by CF. METHODS AND RESULTS: In a double-blinded controlled superiority trial, we randomized patients 1:1 to receive CA for typical AFL guided by CF (intervention group) or blinded to CF (control group). In the intervention group, a specific value of the lesion size index (LSI), estimating ablation lesions size was targeted for each ablation lesion. Patients underwent electrophysiological study (EPS) after 3 months to assess occurrence of the primary endpoint of re-conduction across the cavo-tricuspid isthmus (CTI). We included 156 patients with typical AFL, median age was 68 [interquartile range (IQR) 61-74] years and 120 (77%) patients were male. At index procedure median LSI was higher in the intervention group [6.4 (IQR 5.1-7) vs. 5.6 (IQR 4.5-6.9), P < 0.0001]. After 3 months, 126 patients (58 in intervention group) underwent EPS for primary endpoint assessment. Thirty (24%) patients had CTI re-conduction, distributed with 15 patients in each treatment group (P = 0.62). We observed no difference between treatment groups with regard to fluoroscopy, ablation, or procedure times, nor peri-procedural complications. CONCLUSION: Contact force-guided ablation does not reduce re-conduction across the CTI after 3 months, nor does CF-guided ablation shorten fluoroscopy, ablation, or total procedure times.