Differences Between Patients with Heartburn Refractory to Vonoprazan and Those Refractory to Proton Pump Inhibitors

Vonoprazan, a potassium-competitive acid blocker, demonstrates more potent acid inhibition than proton pump inhibitors (PPIs). This study aimed to evaluate the effect of vonoprazan in patients with unproven gastroesophageal reflux disease (GERD) by comparing patients with vonoprazan-refractory heartburn with those with PPI-refractory heartburn. This study included 104 consecutive patients with vonoprazan- or PPI-refractory heartburn (52 patients each), no erosive esophagitis on endoscopy and who underwent combined multichannel intraluminal impedance–pH (MII–pH) testing with vonoprazan/PPI discontinuation. Patients’ backgrounds, symptom scores from four questionnaires, MII–pH results and high-resolution manometry results were compared between the two groups. The vonoprazan group demonstrated significantly higher GERD symptoms and scores of abdominal pain and diarrhea on the Gastrointestinal Symptom Rating Scale questionnaire. MII–pH results revealed that the vonoprazan group demonstrated 40.4