Very long-term outcomes after catheter ablation of atrioventricular nodal reentrant tachycardia: How does cryoenergy differ from radiofrequency?

Introduction: Either cryoenergy or radiofrequency can be used during atrioventricular nodal reentrant tachycardia (AVNRT) ablation. There are still limited data comparing their respective long-term efficacy (>1 year). This study sought to compare the very long-term outcomes of AVNRT ablation using radiofrequency or cryotherapy.

Methods: We retrospectively included all patients who had undergone a first AVNRT ablation in our institution between January 2010 and December 2017. The primary endpoint was recurrence of documented AVNRT.

Results: The study population consisted of 409 patients (274 females; mean age, 49.9 years). Ablation was performed using cryoenergy in 260 patients and radiofrequency in 149. High acute procedural success rate (>98%) was obtained and no permanent AV block was observed using both techniques. During a mean follow-up of 3.3 ± 2.3 years, documented AVNRT recurrence occurred in 24 (9.2%) and 4 patients (2.7%) in the cryoablation (CA) and radiofrequency (RF) group, respectively. The risk of AVNRT recurrence was significantly higher in the CA group as compared with the RF group (hazard ratio [HR] = 3.7; 95% confidence interval [CI], 1.3-5.9). Most of the recurrences after CA occurred between 1- and 6-year follow-up (14/24; 58.3%), with one-third of late recurrences after 3-year follow-up. In multivariable analysis, only Koch's triangle anatomical variant was associated with AVNRT recurrence after CA (HR = 6.7; 95% CI, 2.7-16.3).

Conclusion: While AVNRT recurrence rates were similar at 1 year of follow-up regardless of the energy used, long-term efficacy appeared higher after radiofrequency ablation. Strikingly, recurrences occured much later after cryotherapy compared with radiofrequency ablation.