Clinical Benefit of Performing 24-Hour pH-Impedance Testing in Addition to 48-Hour pH Capsule Studies During Evaluation of Patients With Suspected Refractory Gastroesophageal Reflux Disease (GERD)

Abstract

Introduction: GERD can present with a wide variety of symptoms, both typical and atypical. When GERD is suspected, quantitative reflux testing can be used to confirm the condition. Evaluation can include placement of a 48-hour wireless pH capsule (Bravo®), which measures acid reflux, or use of a 24-hour transnasal esophageal pH-impedance catheter to measure both acidic and non-acidic reflux. Most patients undergo only one of these tests. There is limited data on the utility of evaluating the same patient with both procedures. Our aim was to assess the benefit of performing 24 hour pH-impedance testing in addition to a 48-hour pH capsule study in patients with refractory GERD symptoms. Methods: All patients undergoing quantitative reflux testing for refractory symptoms at our institution between January 2010 and December 2013 were considered for the study. Patients were included in the analysis if they completed both 48-hour pH capsule and 24-hour pH-impedance testing within one year, as long as they were off acid reduction therapy for 1 week before capsule placement. Biopsies taken during upper endoscopy also had to be negative for eosinophilic esophagitis and H. pylori. Results: Fifteen patients met the inclusion criteria. Most (80%) were female, with a mean age of 51 years. The most common indication for testing was heartburn, followed by chest pain, regurgitation, cough, hoarseness and abdominal pain. All but 3 patients were on a PPI for their impedance testing. Of the 6 patients with a positive 48-hour capsule study, 3 (50%) demonstrated GERD refractory to acid reduction therapy measured by overall impedance. An additional patient had increased weakly acidic reflux. All 4 patients were considered for anti-reflux surgery based on these findings. Nine patients had a negative 48-hour capsule study. However, 8 (89%) of these patients had impedance testing that confirmed abnormal weakly acidic (50%), non-acidic (25%) or both weakly and non-acidic reflux (25%). These patients were diagnosed with esophageal visceral hypersensitivity, and the majority of them (4/7) subsequently started on tricyclic therapy reported symptomatic improvement during a follow-up office visit. Conclusion: In patients with persistent GERD symptoms despite aggressive treatment, there is a clear benefit to adding 24-hour pH-impedance testing to 48-hour pH capsule testing. In 12 of 15 patients (80%), impedance testing was abnormal and changed management. Surprisingly, impedance testing was positive in 89% of patients with a negative 48-hour pH capsule test. While pH capsule remains more widely available, pH-impedance ultimately may have greater utility, as it can be used for initial GERD diagnosis as well as evaluation of refractory symptoms on therapy. Disclosure - Dr. Smith - Consultant: Covidien-GI Solutions.