169 THE RELATIONSHIPS BETWEEN SYMPTOMS, REFLUX PH VALUES, AND EXTENT OF REFLUX IN PATIENTS WITH P-CAB-RESISTANT NERD

Abstract

Abstract In patients with proton pump inhibitor-resistant non erosive reflux disease (NERD) having symptoms associated with liquid reflux, there are reports that reflux symptoms are more likely to be caused by the proximal extent of the reflux and reflux where pH <5. The objective of this study was to investigate the relationships between symptoms, reflux pH values, and the extent of reflux in patients with potassium-competitive acid blocker (P-CAB)-resistant NERD. Methods The subjects were 20 patients with P-CAB-resistant NERD whose symptoms did not improve even after administration of P-CAB (vonoprazan 20 mg/day) for 2–4 weeks. Their symptom index was positive for liquid reflux in impedance–pH monitoring. We investigated reflux pH values in symptomatic and asymptomatic reflux events, proportion of symptomatic reflux events according to the reflux pH value (pH <5 or ≥ 5), proportion of symptomatic reflux events at each impedance site, and proportion of symptomatic reflux events at each impedance site according to the reflux pH value (pH <5 or ≥ 5). Results About 60% of the symptomatic reflux events were caused by reflux with pH ≥5 in patients with P-CAB-resistant NERD. The median reflux pH value for total reflux events was 5.3 and that for symptomatic reflux events was 5.2. The proportion of symptomatic reflux events caused by reflux with pH <5 was significantly higher than that caused by reflux with pH ≥5. Symptomatic reflux events for reflux with pH <5 are more likely to be caused by proximal extent. There was no difference in the proportion of symptomatic reflux events for reflux with pH ≥5 at each reflux extent site. Conclusion In patients with P-CAB-resistant NERD, their symptoms were often caused by reflux with pH ≥5. A difference in the relationship between the reflux extent site and appearance of symptoms was observed according to the reflux pH value.