Cryoablation with an 8-mm tip catheter in the treatment of atrioventricular nodal re-entrant tachycardia: results from a randomized controlled trial (CRYOABLATE)

This was a randomized controlled study performed to compare 8 mm-tip catheter cryoablation (CRYO) with radiofrequency ablation (RFA) in treating atrioventricular nodal re-entrant tachycardia (AVNRT).

A total of 158 patients (103 women, mean age 48.9 ± 14.1) with symptomatic AVNRT (140 typical; 18 atypical) were randomized to undergo CRYO with an 8 mm-tip catheter (n = 80) or RFA (n = 78). The primary endpoint was a composite of acute procedural failure, inadvertent permanent atrioventricular block (AVB) and recurrence at 12 months. No significant difference was observed between CRYO and RFA groups in primary endpoint (7.5 vs. 11.5%; P = 0.764), 12-month recurrence rate (3.8 vs. 1.3%; P = 0.358), inadvertent permanent AVB (0 vs. 1.3%; P = 0.307), and acute procedural failure (3.7 vs. 9%; P = 0.128). In patients with acute procedure failure, success was achieved in 5 of 7 patients (71.4%) in RFA group and 2 of 3 patients (66.7%) in CRYO group on cross-over. There was no significant difference in procedural duration between CRYO and RFA groups (72.4 ± 41.6 vs. 63.7 ± 29.8 min; P = 0.13), but fluoroscopic duration in CRYO group was significantly shorter (3.4 ± 6.3 vs. 6.7 ± 7.4 min; P = 0.005). Patient pain score (2.7 ± 2.7 vs. 4.6 ± 2.7; P < 0.001) and operator stress score (2.3 ± 1.3 vs. 4.9 ± 2; P < 0.001) were significantly lower in CRYO group.

Cryoablation with an 8 mm-tip catheter is shown to be comparable to RFA in treating AVNRT in terms of efficacy and safety. Additional advantages in CRYO include shorter fluoroscopic time, lower patient pain perception, and operator stress level.