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 20mm. 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 25mm. 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 +/- 12.4years, 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 +/- 18.9min in the SMC1 group and 74.4 +/- 19.1min in the SMC2 group (p=0.432). Mean fluoroscopy time was also not different between both study groups (SMC1 15.7 +/- 6.6min, SMC2 15.7 +/- 7.3min, 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.