In vivo safety and pulmonary vein isolation performance of a new cryoballoon for the treatment of atrial fibrillation.

Background: Cryoablation to achieve pulmonary vein (PV) isolation has become one of the standard approaches for atrial fibrillation (AF) ablation. The Arctic Front series cryoballoon and Achieve circular mapping catheter (Medtronic) inherently possess design defects that have been associated with unfavorite clinical outcomes. Lately, a new cryoablation system (Nordica Cryoablation System, Synaptic Medical) was developed with improved design of the cryoballoon and circular mapping catheter to address the inadequacies of current cryoablation technology. An animal study was conducted to test the efficacy and safety in performing PVI with the Nordica Cryoablation System.

Methods: Pulmonary vein isolation with the Nordica Cryoablation System was performed on 12 PVs of six healthy canines. Acute PVI and peri-procedural complications were recorded. All animals underwent a repeat EP study at least 4 weeks after index procedures followed by pathological and histological assessments of the heart and collateral/downstream organs after planned euthanasia.

Results: Acute PV isolation was achieved in all targeted PVs with 50% of PVs being isolated with a single cryoablation application. There were no major peri-procedural complications or device malfunction events. All PVs remained isolated after 29-30 days follow-up. Histological examination showed transmural cryo-lesions at treated sites with minimal inflammation, neovascularization, and neointima formation but no significant injury to adjacent tissue or embolization in downstream organs.

Conclusion: Acute and durable PVI can be achieved by using the novel Nordica Cryoablation System. Ablation with this new cryoablation system is associated with transmural lesions at targeted myocardium but creates no injury to the collateral tissues or downstream organs.