The finding of posterior wall low-voltage zones during cryoballoon pulmonary vein isolation facilitated by periprocedural electroanatomical mapping predicts a worse ablation outcome

Abstract Background The addition of periprocedural electroanatomical mapping (EAM) to cryoballoon ablation (CBA) has shown to improve acute pulmonary vein isolation (PVI) rate and 1-year clinical outcome of cryoballoon ablation (CBA) for atrial fibrillation (AF).(1) The presence of left atrial low-voltage zones (LVZ) in high-density EAM is correlated with a higher atrial arrhythmia recurrence rate after ablation.(2) However, the prognostic value of the finding of LVZ using non-high density periprocedural EAM during CBA is not known. Purpose To compare clinical characteristics between patients with and without LVZ and evaluate the prognostic value of the finding of LVZ using periprocedural EAM during CBA. Methods A cohort of 250 consecutive patients who underwent index CBA for atrial fibrillation was retrospectively analyzed. All patients underwent pre- and post-procedural EAM using the Achieve catheter and EnSite mapping system. The presence of LVZ was evaluated at the postprocedural voltage map of the posterior wall. Clinical success was defined as freedom of documented AF or atrial tachycardia (AT) >30s after 1 year. Results Posterior wall LVZ was found in 41/250 (16.4%) of patients. Patients with LVZ were older (69.3±8.5 vs 64.2±10.4; P=0.003), more frequent female (63.4% vs 32.5%; P<0.001) and had higher CHADS-VASc scores (3.0±1.6 vs 2.0±1.5; P<0.001). The incidence of structural heart disease (35.5% vs 17.4%; P=0.021) and persistent AF (68.3% vs 43.8%; P=0.004) was higher in the LVZ group. Kaplan-Meier analysis of clinical outcome showed a higher recurrence rate in the LVZ group. The absence of LVZ was a predictor of atrial arrhythmia free survival at 1 year (HR=0.210; 95%CI 0.080-0.304; P<0.001). Conclusions The finding of posterior wall LVZ using periprocedural EAM during index CBA predicts a worse ablation outcome. This provides an additional advantage of the addition of periprocedural EAM to CBA.Clinical characteristics Kaplan-Meier clinical outcome