Background: Pulmonary vein isolation (PVI) with cryoballoon ablation (CBA) is routinely guided by fluoroscopy and utilizes contrast injection to ensure catheter positioning and pulmonary vein occlusion. Non-fluoroscopic imaging techniques including electromagnetic mapping (EM) and intracardiac echocardiography (ICE) have demonstrated reduced fluoroscopy times and contrast exposure. Utilization of color flow Doppler to evaluate vein occlusion with the balloon has not been evaluated as an alternative to contrast injection. In this study we evaluate the effectiveness of cryoablation guided by EM and ICE along with color Doppler to achieve PVI.
Methods: We designed a retrospective cohort study comparing patients who were treated before and after implementation of EM (Carto 3, Biosense Webster) and ICE during CBA (AF Solutions, Medtronic). We analyzed patients receiving CBA with fluoroscopy plus EM and ICE (group 2; N = 24) versus fluoroscopy alone (group 1; N = 25). Procedural success was defined as freedom from atrial fibrillation or other atrial arrhythmias at 1 year post ablation. Primary outcomes were radiation time and contrast exposure.
Results: Procedural success was achieved in all cases. Total fluoroscopy time was reduced from 22.4 ± 9.8 min to 8.9 ± 5.1 min (P < 0.001) in patients receiving CBA guided by EM and ICE. Furthermore, exposure to contrast media was significantly lower at 75.4 ± 24.1 ml and 16.5 ± 21.1 ml (P ≤ 0.001) in group 1 and group 2, respectively. Neither the number of required cryotherapy treatments nor procedure duration was negatively impacted by the implementation of non-fluoroscopic techniques. The 1-year success rate was identical between both groups at 72% and 79%. There was no difference in complication rates.
Conclusion: This single-center cohort study demonstrates that CBA guided by EM and ICE can markedly reduce radiation and contrast exposure with excellent rates of acute PVI. This technique may be particularly effective in patients sensitive to intravenous contrast exposure.
Keywords: Cryoballoon ablation; Fluoroscopy; Pulmonary vein isolation; Radiation exposure.