Plasma histidine as biomarker for recurrent atrial fibrillation after catheter ablation

Atrial fibrillation (AF) is associated with complex and multifaceted etiology including neural modulation that alters atrial electrophysiology. To explore potential biomarkers for AF and AF recurrence. Peripheral histidine levels in PeAF were significantly higher compared to those in the right atrium and coronary sinus. Receiver operating characteristic (ROC) analysis revealed that peripheral histidine was predictive of AF recurrence, with an optimal cutoff value of ≤ 4.71 µg/mL, yielding a sensitivity of 76.3% and a specificity of 76.5%. The area under the ROC curve (AUC) was 0.75 (95% CI, 0.59–0.90). Peripheral His was robustly associated with lower incidence of AF recurrence after covariates adjustment (OR 0.34, 95% CI 0.14- 0.71, p=0.01). To investigate the cardiac effect of histidine, we isolated neonatal rat cardiomyocytes and stimulated these cells with 100nM histidine for 72 h hours with or without 1 μM doxorubicin .