Abstract
BACKGROUND/AIMS: A diagnosis of gastroesophageal reflux disease is challenging in patients who have reflux symptoms but do not respond to proton pump inhibitors nor have reflux esophagitis and hiatal hernia (HH) on endoscopy. This study examined the predictive role of the endoscopic findings, including the flap valve grade for pathologic acid exposure (PAE) to establish an endoscopic prediction model in patients with neither reflux esophagitis nor HH. METHODS: Five hundred seventy-eight patients who underwent upper endoscopy and 24 hours pH monitoring for reflux esophageal symptoms without evidence of reflux esophagitis and HH were analyzed. The gastroesophageal flap valve (GEFV), esophageal metaplasia, and chronic atrophic gastritis were assessed. The association between the endoscopic parameters and PAE was evaluated. RESULTS: Four hundred ninety-four patients were enrolled. The most common complaint was chest discomfort (42.3%) followed by globus (31.8%), dysphagia (7.9%), and heartburn (7.7%). PAE was present in 43 patients (8.7%). Multivariable analysis revealed PAE to be associated with the GEFV grade (p<0.001) and inversely associated with the chronic atrophic gastritis grade (p=0.005). Using these features, a predictive model was established and showed an area under the receiver operating characteristic curve of 0.705 (95% CI 0.619-0.790). The cutoff value of 12.0 had a sensitivity and specificity of 44.0% and 84.0%, respectively. CONCLUSIONS: A loosened GEFV is associated with a risk of PAE in patients with neither reflux esophagitis nor HH, while atrophic gastritis is preventive. On the other hand, the endoscopic predictive model revealed a low sensitivity for detecting PAE. Thus, reflux testing needs to be performed further when gastroesophageal reflux disease is suspected, even without endoscopic evidence.