Association between post‐reflux swallow‐induced peristaltic wave index and esophageal mucosal integrity in patients with GERD symptoms

Abstract

Background Impedance‐pH monitoring allows evaluation of esophageal chemical clearance, a response to reflux elicited by the esophago‐salivary reflex, by means of the post‐reflux swallow‐induced peristaltic wave (PSPW) index; mucosal integrity can be evaluated by means of mean nocturnal baseline impedance (MNBI) and is regarded as a GERD marker. Currently, the relationship between PSPW index and MNBI has not yet been fully investigated and represents the aim of the present study. Methods Impedance‐pH tracings from consecutive patients were reviewed. ROC analysis and multivariate regression models were generated to evaluate the association between acid exposure time (AET), total refluxes (TRs), PSPW index, and MNBI. Patients were classified by means of AET thresholds and symptom‐reflux association indexes into conclusive and inconclusive GERD, reflux hypersensitivity (RH), and functional heartburn (FH). Pathologic MNBI <2292 Ω was defined according to published outcome studies. Key Results Two hundred and thirty patients constituted the study cohort. Overall, a significant direct correlation was observed between PSPW index and MNBI (0.759, p < 0.001). At ROC analysis, a PSPW index cut‐off value of 53% was the best discriminator between normal from pathologic MNBI values (sensitivity 88%, specificity 86.4%). Considering AET cut‐off of 4% or 6%, a sensitivity of 80.7% and 46% and a specificity of 62.5% and 93.2% were found, respectively. According to multivariate analysis, AET >4% and PSPW index value <53% or <61% were significantly associated with pathologic MNBI values. Conclusions and Inferences Esophageal chemical clearance is a major defense mechanism against reflux and its impairment represents a major determinant of reflux‐associated mucosal damage.

Esophageal secondary peristalsis following acid infusion and chemical clearance correlate with mucosal integrity and acid sensitivity in GERD patients

“… 20 , 30 According to the latest research results, we employed two cut-off points, PSPW indices of <53% and <61%, to indicate impaired esophageal chemical clearance. 31 …”

“…20,30 According to the latest research results, we employed two cutoff points, PSPW indices of <53% and <61%, to indicate impaired esophageal chemical clearance. 31 The duration of bolus contact time in each reflux episode was determined by calculating the interval between the first instance of impedance drop below 50% of the baseline, indicating the onset of reflux, and the subsequent return to 50% of the baseline impedance level in the distal impedance channel, signifying the conclusion of the reflux event.…”

Mean nocturnal baseline impedance, a novel metric of multichannel intraluminal impedance-pH monitoring in diagnosing gastroesophageal reflux disease

“… 21 , 43 The proportion of abnormal MNBI was significantly higher in patients with AET > 6% or AET 4–6% than in patients with AET > 4%. 27 Ribolsi et al 44 prospectively performed a multicenter study that enrolled 230 patients with dominant typical esophageal symptoms, which demonstrated that AET was negatively correlated with MNBI values. In addition, AET > 4% was significantly associated with abnormal MNBI values.…”

“…In addition, AET > 4% was significantly associated with abnormal MNBI values. 44 The correlation between AET and MNBI may be that the increased reflux burden results in the impaired integrity of esophageal mucosa, as shown by decreased MNBI values.…”

Letter: should we have to include baclofen in the GORD therapy armamentarium? authors' reply

“…We used cut-off values for abnormal MNBI of both <2290 Ω and <2000 Ω, according to latest evidence. 9,10 Results are summarised in Table 1. In this small sample, we did not observe a difference in response to baclofen in patients with pathological MNBI as opposed to normal MNBI (with pathological MNBI defined both as <2290 Ω, p = 0.85 and <2000 Ω, p = 0.92).…”