Systematic Workflow and Electrogram Guidance to Reduce X-ray Exposure Time During Cryoballoon Ablation of Atrial Fibrillation: The SWEET-Cryo Strategy.

Abstract

Cryoballoon pulmonary vein isolation (CB-PVI) offers similar efficacy to point-by-point radiofrequency PVI for patients with atrial fibrillation (AF), but generally with higher X-ray exposure. Strategies aimed at reducing fluoroscopy mostly rely on other costly imaging techniques, limiting their applicability. We designed a Systematic Workflow and Electrogram guidance to reduce X-ray Exposure Time during CB-PVI (SWEET-Cryo) strategy and analyzed its impact on fluoroscopy use and acute procedural and clinical outcomes. We enrolled 100 patients with paroxysmal or persistent AF undergoing CB-PVI by two operators with different levels of expertise. Patients treated with the SWEET-Cryo strategy (prospective cohort; n=50) or conventional fluoroscopy (retrospective control cohort; n=50) were compared. When applied by the senior operator, the SWEET-Cryo strategy significantly reduced the mean fluoroscopy time (FT) (2.6±1.25 vs. 20.3±10.8 min) and mean dose-area product (5.1±3.8 vs. 35.3±22.3 Gycm2) compared with the control group, respectively (p<0.001). Significant reductions in FT (6.4±2.5 min vs. 32.5±10.05) and DAP (13.9±7.7 vs. 92.3±63.8) were also achieved by the less experienced operator, respectively (p<0.001). No difference was observed in acute and long-term complications or freedom from AF between fluoroscopy strategies during a 33-month median follow-up. Mean FT was maintained below 3 min in randomly selected cases performed during the follow-up period. In contrast to conventional protocols and regardless of the operator's experience, the optimized SWEET-Cryo strategy dramatically reduced fluoroscopy exposure during CB-PVI. The efficacy, safety, or added costs of the ablation procedure were not compromised.