The impact of steerable sheaths on unblinded contact force during catheter ablation for atrial fibrillation

The purpose of this study was to evaluate the impact of steerable sheaths on multiple contact force parameters during atrial fibrillation (AF) ablation. Steerable sheaths are commonly used during AF ablation, at an additional cost to standard fixed-curve sheaths. However, there is little data on their incremental value in the era of contact force-guided radiofrequency ablation.

This multi-center cohort study included consecutive patients undergoing index pulmonary vein (PV) isolation with a force-sensing catheter. Operators employed either only steerable or only fixed-curve sheaths. Operators targeted a force of 10-40 g for each ablation lesion. Automated ablation lesion assessment software with standardized settings was employed.

Of 85 subjects, 52 and 33 underwent ablation with steerable and fixed-curve sheaths, respectively. The steerable sheath group showed significantly higher average and maximum forces, but predominantly for the right PVs. The proportion of lesions with ≥ 10% of time with less than 10 g of force was lower in the steerable sheath group (adjusted odds ratio 0.56, steerable vs. fixed; 95% confidence interval 0.35, 0.89, p = 0.01). Improved stability was seen in the posterior aspect of both PV pairs. The proportion of RF time-in-target (the proportion of RF time meeting lesion criteria) was not different between the two groups (p = 0.176).

Even with contemporary contact force targets, steerable sheath use in AF ablation is associated with better average and maximum contact force and increased stability in comparison to fixed-curve sheaths.