Mean Nocturnal Baseline Impedance and Post-reflux Swallow-induced Peristaltic Wave Index Could Identify Gastroesophageal Reflux Disease but pH-Impedance Metrics Alone Might Not Correlate With Proton Pump Inhibitor Response in Chinese Patients With Typical Reflux Symptoms.

Abstract

Background/AimsLyon consensus differentiates acid exposure time (AET) as physiological, borderline, and pathological. Mean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave index (PSPWi) are believed to increase diagnostic yield of gastroesophageal reflux disease (GERD) and correlate with symptom outcome of proton pump inhibitor (PPI) treatment. We aim to explore the clinical characteristics and the correlation of pH-impedance parameters with PPI response in Chinese patients with different AET levels.MethodsWe retrospectively investigated 177 patients with typical reflux symptoms who received esophageal function tests. The demographics, GERD questionnaire scores, the proportion of esophagitis and PPI responders, and manometric and pH-impedance parameters were compared among patients with AET < 4%, 4-6%, and > 6%. In patients with AET ≥ 4%, manometric and pH-impedance parameters were compared between PPI responders and non-responders.ResultsAmong 177 patients, 69 (39.0%) had AET 4-6%, and 53 (29.9%) had AET > 6%. The demographics, esophagogastric junction type, and occurrence of ineffective esophageal motility were similar between patients with AET 4-6% and > 6%, but different from AET < 4%. MNBI and PSPWi were different among different AET levels, but similar between PPI responders and non-responders in patients with AET ≥ 4%.ConclusionsIt is reasonable to set 4% as a threshold to define pathological AET in Chinese patients. MNBI and PSPWi could identify GERD patients, but may not correlate with PPI response of Chinese GERD patients.