The Lyon Consensus put forward a hierarchical approach for the diagnosis of gastro-esophageal reflux disease (GERD) by impedance-pH monitoring, which was based on acid exposure time (AET) and supportive impedance metrics.

A study was conducted to determine the clinical value of Lyon Consensus criteria in the work-up of patients with heartburn refractory to proton pump inhibitory (PPI) treatment.

The methods of the study included an expert review of off-therapy impedance-pH tracings from unproven GERD patients with PPI-refractory heartburn who were evaluated at referral centers; evaluation of impedance metrics, such as total reflux episodes, postreflux swallow-induced peristaltic wave index, and mean nocturnal impedance at baseline; and expert review of on-therapy impedance-pH tracings prior to surgery from a different cohort of surgically treated erosive/nonerosive GERD patients.

• Off-therapy, normal AET was found in 59% patients, inconclusive in 17%, and abnormal AET was noted in 23% out of 317 cases.
• Abnormal impedance metrics provided evidence of GERD in up to 22% and 62% of cases in the normal and inconclusive AET groups, respectively.
• When the cases with inconclusive AET and abnormal impedance metrics were added to the abnormal AET group, there was a significant rise in GERD evidence, from 23% to 37% of cases.
• At the on-therapy presurgical assessment, abnormal or inconclusive AET and supraphysiological impedance metrics values pointed to ongoing reflux in 21% and 90% of the 96 cases, respectively.
• A favorable surgical outcome at 3-year follow-up validated the link between on-therapy ongoing reflux and PPI-refractory heartburn. About 88% of cases were in persistent off-PPI heartburn remission.

Researchers concluded that impedance-pH monitoring, both off- and on-therapy, is of clinical value in the work-up of patients having PPI-refractory heartburn.

Source: Frazzoni M, Frazzoni L, Ribolsi M, et al. Applying Lyon Consensus criteria in the work-up of patients with proton pump inhibitory-refractory heartburn. Aliment Pharmacol Ther. 2022 Feb 28.