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

Abstract

Either cryoenergy or radiofrequency can be used during atrioventricular nodal reentrant tachycardia (AVNRT) ablation. There is 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. 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. The study population consisted of 409 patients (274 females, mean age 49.9 year-old). 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 and radiofrequency group respectively. The risk of AVNRT recurrence was significantly higher in the CA group as compared to the RF group (hazard ratio = 3.7, 95% CI: 1.3 to 5.9). Most of the recurrences after cryoablation occurred between 1- and 6-year follow-up (14/24; 58.3%), with 1/3rd of late recurrences after 3-year follow-up. In multivariable analysis, only Koch's triangle anatomical variant was associated with AVNRT recurrence after cryoablation (hazard ratio = 6.7, 95% CI: 2.7–16.3) ( Fig. 1 ). While AVNRT recurrence rates were similar at one year of follow-up regardless of the energy used, long-term efficacy appeared higher after radiofrequency ablation. Strikingly, recurrences occurred much later after cryotherapy compared to radiofrequency ablation.