Urinary isoxanthopterin as a novel predictor following catheter ablation for atrial fibrillation

J Arrhythm. 2023 Feb 27;39(2):159-165. doi: 10.1002/joa3.12828. eCollection 2023 Apr.

Abstract

Background: Oxidative stress is associated with atrial fibrillation recurrence following catheter ablation. Urinary isoxanthopterin (U-IXP) is one of the noninvasive markers which reflect the reactive oxygen species; however, its ability to predict atrial tachyarrhythmias (ATAs) occurrence following catheter ablation remains uncertain.

Methods: Among the patients who received scheduled catheter ablation for atrial fibrillation, baseline U-IXP levels were measured just before the procedure. The prognostic impact of baseline U-IXP upon postprocedural ATAs occurrence was investigated.

Results: Among 107 patients (71 years old, 68% men), baseline U-IXP level was 0.33 nmol/gCr on the median. During a mean of 603 days of follow-up, 32 patients had ATAs. Baseline higher U-IXP was independently associated with the occurrence of ATAs following catheter ablation with a hazard ratio of 4.69 (95% confidence interval: 1.82-12.37, p = .001) adjusted for the left atrial diameter, a persistent type, and hypertension which were potential confounders, with a cutoff of 0.46 nmol/gCr, which stratified cumulative incidence of ATAs occurrence ( p < .001).

Conclusion: U-IXP can be used as the noninvasive predictive biomarker for ATAs following catheter ablation for atrial fibrillation.

Keywords: atrial fibrillation; atrial tachyarrhythmias; oxidative stress; urinary isoxanthopterin.