Prospective validation of reflux monitoring by impedance-pH in predicting PPI response in typical GERD

The Lyon Consensus proposed a hierarchical approach to GERD diagnosis based on conventional and new impedance-pH metrics, namely acid exposure time (AET), number of reflux episodes, post-reflux swallow-induced peristaltic wave (PSPW) index, and mean nocturnal baseline impedance (MNBI).To define the value of conventional and new impedance-pH parameters as predictors of response to label-dose PPI in typical GERD.Consecutive adult patients with typical esophageal symptoms were prospectively studied with impedance-pH monitoring and treated with 8-week label-dose PPI. At the end of the PPI course, symptoms response was assessed.Among 255 patients who entered the study, 168 (65.9%) reported symptom remission. At ROC analysis, both MNBI and PSPW index were significantly associated to PPI responsiveness with AUC of 0.783 and 0.801, respectively. Cut-off values of 1747Ω for MNBI and 50% for PSPW index were identified as discriminators between response and non-response to label-dose PPI. At multivariate analysis, MNBI, PSPW index, and AET6% were efficient predictors of PPI responses (OR 3, 5.4 and 2.3, respectively). Number of reflux episodes did not predict PPI response.The novel MII-pH variables together with pathological are highly predictive of response of the typical GERD syndrome to label-dose PPI.