Achieving contrast-free ultra-low radiation exposure without compromising safety and acute efficacy through evolving AF cryoballoon ablation procedure techniques.

Introduction: In general, early experience with the first-generation cryoballoon introduced an increase in radiation exposure as compared to traditional radiofrequency ablations for atrial fibrillation (AF). However, through operator vigilance and the incorporation of various techniques and technologies, procedural radiation exposure can be managed to an exceptionally low level while maintaining the safety and efficacy of the cryoballoon procedure.

Methods And Results: A retrospective chart review of all consecutive AF ablation procedures performed by a single operator at a single high-volume center with the second-generation cryoballoon (Arctic Front Advance) was performed between 2014 and 2017. Procedural and radiation exposure data were collected and analyzed year-over-year. 307 cases were reviewed with the majority as index procedures (95%) and patients presenting in paroxysmal AF (87%). The observed median absorbed dose was 2.4 mGy (interquartile range (IQR) = 1.0,6.2) and decreased significantly from 6.7 mGy (IQR = 1.6,6.2) in 2014 to 2.0 mGy (IQR = 1.5,4.5) in 2017 (P < 0.001). Median fluoroscopy time was 0.4 min (IQR = 0.25,0.75) and demonstrated reductions from 0.75 min (IQR = 0.40,1.4) in 2014 to 0.20 min (IQR = 0.10,0.40) in 2017 (P < 0.001). No radiopaque contrast agent was used in any procedure. A complication rate of 2% (6 total events) was observed, and no cases resulted in stroke, death, permanent phrenic nerve injury, or pulmonary vein stenosis. In total, 304 of 307 (99%) procedures resulted in complete isolation of all pulmonary veins.

Conclusion: Ultra-low radiation doses and contrast-free procedures can be achieved as part of an overall "safety-first" approach during cryoballoon AF ablation without compromising safety or acute efficacy.