Efficacy of temperature-guided cryoballoon ablation without using real-time recordings - 12-Month follow-up.

Background: We sought to evaluate a temperature-guided approach of cryoballoon (CB) ablation without visualization of real-time recordings.

Methods and results: We analysed 166 patients (34.9% female, 60 ± 11 years) with paroxysmal or short-term persistent atrial fibrillation (AF). Comorbidities included diabetes mellitus (n = 28), coronary artery disease (n = 24), hypertension (n = 122), previous stroke or TIA > 3 months (n = 12). Cryoablation of the pulmonary veins (PV) was performed using first-generation (n = 78) and second-generation CB (n = 88). Two 5-minute freezes were performed for the first-generation and two 4-minute freezes for the second-generation CB with the intention to achieve a temperature drop below -40 °C. At 12-month follow-up, we observed overall freedom from AF in 92 patients (56.6%, mean time to AF recurrence 3.4 ± 2.9 months). There was a significant difference in freedom from AF between first-generation CB (45%) and second-generation CB (67%; p < 0.005). Complications were groin hematoma (4.8%) and phrenic nerve palsy (PVP) (2.4%). PVP disappeared after 12 months in all patients. Three patients developed cardiac tamponade (1.8%) that resolved without further sequelae after pericardiocentesis. Multivariate analysis revealed that only the achieved temperature in the right inferior PV (RIPV) was a predictor of long-term freedom from AF (OR 0.9; p = 0.014). Female gender was a predictor of AF recurrence (OR 6.1; p = 0.022).

Conclusion: Temperature-guided CB ablation without real-time recordings is feasible and safe without reducing the efficacy if second-generation CB is used. Deep nadir temperatures especially in the RIPV are necessary for long term-success.