Fecal calprotectin: A novel predictor of ulcerated esophageal injury after atrial fibrillation catheter ablation

Background: Atrial esophageal fistula (AEF) is a lethal complication that can occur post atrial fibrillation (AF) ablation. Esophageal injury (EI) is likely to be the initial lesion leading to AEF. Endoscopic examination is the gold standard for a diagnosis of EI but extensive endoscopic screening is invasive and costly. This study was conducted to determine whether fecal calprotectin (Fcal), a marker of inflammation throughout the intestinal tract, may be associated with the existence of esophageal injury.Methods: This diagnostic study was conducted in a cohort of 166 patients with symptomatic AF undergoing radiofrequency catheter ablation from May 2020 to June 2021. Fcal tests were performed 1-7 days after ablation. All patients underwent endoscopic ultrasonography 1 or 2 days after ablation.Results: The levels of Fcal were significantly different between the EI and non-EI groups (404.9 mu g/g (IQR 129.6-723.6) vs. 40.4 mu g/g (IQR 15.0-246.2), p < .001). Analysis of ROC curves revealed that a Fcal level of 125 <mu>g/g might be the optimal cut-off value for a diagnosis of EI, giving a 78.8% sensitivity and a 65.4% specificity. The negative predictive value of Fcal was 100% for ulcerated EI.Conclusions: The level of Fcal is associated with EI post AF catheter ablation. 125 mu g/g might be the optimal cut-off value for a diagnosis of EI. Negative Fcal could predict the absence of ulcerated EI, which could be considered a precursor to AEF.