title: The added value of quantitative analysis of on-therapy impedance-pH parameters in distinguishing refractory non-erosive reflux disease from functional heartburn.
abstract: BACKGROUND
  By analysis of symptom-reflux association, endoscopy-negative refractory heartburn can be related to acid/non-acid refluxes with impedance-pH monitoring. Unfortunately, patients frequently do not report symptoms during the test. We aimed to assess the contribution of quantitative analysis of impedance-pH parameters added to symptom-reflux association in evaluating patients with endoscopy-negative heartburn refractory to high-dose proton pump inhibitor therapy.
  
  
  METHODS
  The symptom association probability (SAP), the symptom index (SI), the esophageal acid exposure time and the number of distal and proximal refluxes were assessed at on-therapy impedance-pH monitoring. Relationships with hiatal hernia and manometric findings were also evaluated.
  
  
  RESULTS
  Eighty patients were prospectively studied. Refractory heartburn was more frequently related to reflux by a positive SAP/SI and/or abnormal impedance-pH parameters (52/80 cases) (65%) than by a positive SAP/SI only (38/80 cases) (47%) (P = 0.038). In patients with refractory non-erosive reflux disease (NERD) defined by a positive SAP/SI and/or abnormal impedance-pH parameters, the prevalence of hiatal hernia was significantly higher (56%vs 21%, P = 0.007) and the mean lower esophageal sphincter tone was significantly lower (18.7 vs 25.8 mmHg, P = 0.005) than in those (35%) with reflux-unrelated, i.e., functional heartburn (FH). On the contrary, no significant difference was observed subdividing patients according to a positive SAP/SI only.
  
  
  CONCLUSIONS
  Quantitative analysis of impedance-pH parameters added to symptom-reflux association allows a subdivision of refractory-heartburn patients into refractory NERD and FH which is substantiated by pathophysiological findings and which restricts the diagnosis of FH to one third of cases.
authors: Fisiopatologia Digestiva, Nuovo Ospedale S. Agostino, Modena, Italy. m.frazzoni@ausl.mo.it
authors: M
authors: M
authors: Frazzoni
authors: R
authors: R
authors: Conigliaro
authors: V G
authors: VG
authors: Mirante
authors: G
authors: G
authors: Melotti
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D050782:Esophageal pH Monitoring; D004942:Esophagitis, Peptic / Q000175:diagnosis* / Q000503:physiopathology; D004947:Esophagus / Q000503:physiopathology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000503:physiopathology; D006356:Heartburn / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies