Assessment of the Multiple Rapid Swallows Test for Gauging Esophageal Reflux Burden in Patients with Refractory Gastroesophageal Reflux Disease

BACKGROUND The multiple rapid swallows (MRS) test is used to assess esophageal contraction reserve. In this study, we characterized the expression of the MRS test in patients with reflux burden and other symptomatic phenotypes with refractory gastroesophageal reflux disease (rGERD). MATERIAL AND METHODS Patients with rGERD who underwent high-resolution manometry (HRM) and esophageal pH-impedance monitoring (EIM) between September 2018 and January 2020 were retrospectively studied. RESULTS We enrolled 151 patients and divided them into 4 phenotypes according to the results of EIM. In phenotype 1, the MRS distal contractile integral (DCI) was significantly positively correlated with acid-liquid reflux episodes. In phenotype 2, lower esophageal sphincter pressure (LES) length was significantly positively correlated with MRS DCI, and MRS/single-swallow (SS) DCI ratio. In phenotype 3, MRS DCI was negatively correlated with the DeMeester score, acid exposure time (AET), upright AET, long-term acid reflux episodes, acid-mixed reflux episodes, recumbent acid reflux episodes, and total acid reflux episodes. There was a significant negative correlation between MRS/SS DCI and recumbent acid reflux episodes. In phenotype 4, nonacid-liquid episodes and recumbent nonacid reflux episodes were significantly higher in the abnormal MRS group. However, acid-gas episodes, weakly acid-gas episodes, and upright gas reflux episodes were higher in the normal MRS group than in the abnormal MRS group. CONCLUSIONS Esophageal contraction reserve is heterogeneous within the reflux burden and symptomatic phenotypes of patients with rGERD.