Steerable versus non-steerable sheaths during pulmonary vein isolation: impact of left atrial enlargement on the catheter–tissue contact force

The influence of left atrial (LA) enlargement on the efficacy of steerable sheath usage during pulmonary vein (PV) isolation is poorly understood. Here, we compared the catheter–tissue contact force (CF) and clinical outcomes between steerable and non-steerable sheaths among patients with different severities of LA enlargement.

In this prospective observational study, 90 consecutive atrial fibrillation patients scheduled for PV isolation (paroxysmal, 67 %) were enrolled and divided into tertiles of the LA volume (LA1, <124 cm³; LA2, 124 to 145 cm³; LA3, ≥146 cm³). An ipsilateral PV isolation was completed using either a steerable (n = 57) or non-steerable sheath (n = 33).

The average CF of each ipsilateral PV was lower in the LA3 group (right 13.8 ± 5.8 g; left 9.7 ± 5.2 g) than LA1 (right 15.6 ± 6.8 g, p = 0.005; left 12.5 ± 5.6 g, p < 0.0001) or LA2 (right 15.2 ± 7.3 g, p = 0.04; left 12.6 ± 5.3 g, p < 0.0001) groups. In total, the average CF around the left PVs was significantly higher with steerable sheaths than without (12.7 ± 5.5 vs. 10.2 ± 4.9 g, p = 0.03). Subgroup analysis revealed that a tendency toward higher CF around the left PVs was observed in the LA3 group (12.3 ± 7.3 vs. 8.5 ± 3.9 g, p = 0.08) but was not in the LA1 and LA2 groups. Further, in the LA3 group, steerable sheath usage showed better clinical outcomes: shorter procedural (55 ± 29 min vs. 81 ± 39 min, p = 0.04) and fluoroscopic times (27 ± 11 min vs. 37 ± 17 min, p = 0.045) and a tendency toward a lower 1-year AF recurrence rate (39 vs. 12 %, p = 0.09).

The beneficial effects of using steerable sheaths were more prominent in patients with severe LA enlargement.