Novel spiral mapping catheter facilitates observation of the time-to-pulmonary vein isolation during cryoballoon ablation

Observation of the time-to-pulmonary vein isolation (TTI) by a spiral mapping catheter has emerged as a valuable procedural parameter in cryoballoon pulmonary vein isolation (PVI). The 1st generation spiral mapping catheter (Achieve, SMC1) has been available as an 8-polar catheter with a distal loop diameter of 15 or 20 mm. The novel spiral mapping catheter (Achieve Advance, SMC2) was designed as a true guidewire and is available, in addition to the sizes of the SMC1, as a 10-polar mapping catheter with a distal loop diameter of 25 mm. Whether these novel features of SMC2 influence procedural characteristics of Cryo-PVI in comparison to SMC1 has not been reported. In this prospective cohort study 158 patients (age 65.1 ± 12.4 years, female 39%, paroxysmal AF 60%) undergoing PVI with the 2nd generation cryoballoon were included. SMC1 was used in 57 patients (36%), whereas 101 patients (64%) underwent Cryo-PVI with the SMC2. All PVs (623/623, 100%) were isolated successfully. Mean procedure duration was 72.0 ± 18.9 min in the SMC1 group and 74.4 ± 19.1 min in the SMC2 group (p = 0.432). Mean fluoroscopy time was also not different between both study groups (SMC1 15.7 ± 6.6 min, SMC2 15.7 ± 7.3 min, p = 0.593). TTI was observed in 68.6% of pulmonary veins in the SMC1 group, whereas TTI observation rate was 82.6% in the SMC2 group (p < 0.001). Number of freezes (5.5 ± 1.5 vs. 6.5 ± 1.9; p = 0.001) and total freeze duration (14.1 ± 4.5 vs. 17.6 ± 5.6; p < 0.001) were increased in the SMC2 group. SMC2 significantly increases TTI observation rate during Cryo-PVI. Procedure duration and fluoroscopy time are similar and number of freezes and total freeze duration are increased compared to PVI with SMC1 due to decreased stability and maneuverability of SMC2.