Comparative Study of Zero/Low Versus Conventional Fluoroscopy Workflows for Ablation of Paroxysmal Atrial Fibrillation in Routine Clinical Practice

Background: Fluoroscopy is traditionally used to guide ablation procedures but exposes patients and physicians to radiation. With new electroanatomic navigation and 3D mapping technologies combined with intracardiac echocardiography, ablation procedures in clinical practice can be conducted without fluoroscopy.

Objectives: To use health system electronic health record (EHR) data from routine clinical practice to compare safety and effectiveness outcomes between zero/low fluoroscopy and conventional fluoroscopy radiofrequency catheter ablation workflow procedures for ablation of paroxysmal atrial fibrillation (PAF).

Methods: This retrospective comparative cohort study included 349 patients who met study eligibility criteria in the Mercy EHR database from January 1, 2015 to March 31, 2021, with follow-up up to June 30, 2021. A descriptive comparison was conducted to compare a composite safety endpoint comprising 12 events within 7 to 90 days post-index ablation (first ablation for PAF) and repeat ablation within 1 year post-index ablation using a zero/low fluoroscopy workflow (≤2 minutes) (n=129) vs. a conventional fluoroscopy workflow (≥3 minutes) (n=170). A sensitivity analysis was conducted using an alternative cutoff of >2 minutes to define the conventional fluoroscopy workflow (n=220). The propensity score weighting method was used to balance baseline covariates between groups. The cumulative incidences and confidence intervals (CI) within each group, and the risk difference between groups were estimated using the Kaplan-Meier method.

Results: Covariate-balanced cumulative incidences of the composite safety endpoint were low and similar between groups (zero/low fluoroscopy workflow group: 0.80% vs. conventional fluoroscopy workflow group: 0.31%), with a risk difference between groups of 0.49% (2-sided 90% CI: -0.97%, 1.95%). One safety event was identified in each group. The results using the cutoff of >2 minutes to define the conventional fluoroscopy workflow were similar to those from the main analysis using the cutoff of ≥3 minutes. Covariate-balanced cumulative incidences of repeat ablation within 1 year post-index ablation were also similar between groups (2.57% vs. 3.04%), with a risk difference of -0.48% (2-sided 90% CI: -4.03%, 3.08%).

Conclusions: Real-world evidence from this comparative study using Mercy EHR data supports the use of zero/low fluoroscopy workflow during PAF ablations and contributed to receiving FDA approval or clearances for adding zero fluoroscopy workflow to the Instructions for Use (IFU) for multiple cardiac ablation and mapping devices. This change keeps the IFUs current with new technology and clinical practice while reducing or eliminating radiation exposure health hazards.