Predictors of sustained isolation of pulmonary vein ostia with cryoballoon ablation using a second-generation cryoballoon Arctic Front Advance

Aim. To determine the electrophysiological and biophysical predictors of sustained isolation of pulmonary vein (PV) ostia, affecting the immediate and longterm results of interventional treatment of atrial fibrillation (AF) using cryoballoon ablation (CBA) with the second-generation cryoballoon Arctic Front Advance. Material and methods. The analysis included 143 PV in 37 patients with a paro-xysmal/persistent form of AF, which, after the primary CBA with the use of the second-generation cryoballoon, carried out additional interventions due to recurrence of AF and/or combined arrhythmia. During the primary CBA, the registration of biophysical and electrophysiological parameters of the procedure was performed. During the ablation in the right PV from the diagnostic electrode installed in the superior vena cava, the ipsilateral phrenic nerve was stimulated (2000 ms, 25 mA). When the phrenic nerve response to stimulation was decreased/disappeared, ablation ceased instantly. At the end of the procedure, isolation control of the PV was performed. A repeat/additional procedure was performed for the recurrence of AF and/or documented combined arrhythmia no earlier than 3 months after the initial ablation. The stability of the LV isolation was assessed using a circular mapping technique. According to the results of mapping, drugs were divided into 2 groups: isolated and with recurrent activity. Results. The frequency of sustained isolation of PV was 67,8%. Recurrent spike activity was recorded in 46 PV (32,2%). Higher frequency of registration of electrical isolation of PV in real time (68% vs 50%, p=0,001), stability of occlusion with a cryoballoon (85,5% vs 69,5%, p=0,024), low values of the minimum cryoballoon temperatures reached (49,2±6,3 vs 44,0±4,9, p<0,0001) and less need for additional applications (8,3% vs 34,7%, p<0,0001) were registered in the group of chronic isolation of PV. Multi-factor analysis of these parameters confirmed the predictor role of the minimum cryoballoon temperature. According to the ROC analysis, the threshold minimum temperature was 45,5° C with a sensitivity of 68% and a specificity of 60,9%. Conclusion. Cryoballoon isolation of PV ostia is an effective and safe method for achieving chronic isolation of PV. The minimum cryoballoon temperature with a threshold value of <-45,5° C is an independent predictor of long-term isolation of PV.