Postreflux swallow‐induced peristaltic wave index from pH‐impedance monitoring associates with esophageal body motility and esophageal acid burden

Abstract

Background Postreflux swallow‐induced peristaltic wave (PSPW) on pH‐impedance monitoring and contraction vigor on high‐resolution manometry (HRM) both assess esophageal peristaltic response. We aimed to evaluate relationships between PSPW and esophageal peristalsis on HRM in the context of reflux disease in this multicenter cohort study. Methods pH‐impedance and HRM studies performed on patients with persisting reflux symptoms were reviewed from 6 centers (5 in Europe and 1 in US). Total, upright and supine acid exposure time (AET) were evaluated from pH‐impedance studies; PSPW index (PSPWI) and mean nocturnal baseline impedance (MNBI) were calculated using standard methodology. Esophageal body contraction vigor was analyzed using distal contractile integral (DCI), and DCI ratio > 1 between single swallows and multiple rapid swallows (MRS) defined presence of contraction reserve. Student's t test, ANOVA, and linear regression were utilized to investigate relationships between PSPW, contraction vigor, and contraction reserve. Key Results Of 296 patients (52.8 ± 0.8 yr, 63% F), median PSPWI was 0.475. Only 24.0% had intact DCI; the remainder had varying degrees of hypomotility. As hypomotility increased, PSPWI and MNBI decreased significantly, while total AET and reflux episodes had an inverse response (P ≤ .002 for each). MRS data were available in 167 (56.4%), 72.5% had contraction reserve. MRS cohorts with normal PSPWI had significantly lower reflux burden compared to low PSPWI, regardless of presence or absence of contraction reserve (P ≤ .001). Conclusions and Inferences PSPWI correlates with esophageal hypomotility and reflux burden, and complements clinical reflux evaluation. Intact PSPW is more relevant to esophageal reflux clearance than contraction reserve.

Reflux characteristics triggering post‐reflux swallow‐induced peristaltic wave (PSPW) in patients with GERD symptoms

“…Rogers et al 18 have recently demonstrated that PSPW index inversely correlates with impairment of esophageal motility and reflux burden, thus supporting the hypothesis that abnormal acid exposure is correlated with impairment of esophageal motility, the latter finding likely contributing to a lower PSPW index value. In contrast, in our series, the overall PSPW index in patients with or without IEM was comparable.…”

“…17 Finally, it has recently been shown that patients with reflux symptoms and evidence of esophageal hypomotility as detected at high-resolution manometry (HRM) are characterized by significantly lower PSPW index values than patients with normal esophageal motility. 18 In order to better elucidate the relationship between reflux properties and PSPW occurrence, we evaluated the characteristics of reflux episodes associated with PSPW occurrence in a large group of patients with typical GERD symptoms.…”

“…Finally, it has recently been shown that patients with reflux symptoms and evidence of esophageal hypomotility as detected at high‐resolution manometry (HRM) are characterized by significantly lower PSPW index values than patients with normal esophageal motility. 18 …”

Clinical use of mean nocturnal baseline impedance and post-reflux swallow-induced peristaltic wave index for the diagnosis of gastro-esophageal reflux disease

“…Of particular note, although a lower PSPW-I correlates with esophageal hypomotility, normal esophageal contractility does not appear to be essential for the generation of effective PSPWs. Additionally, the integrity of PSPWs seems to be more relevant than the contractile reserve for the clearance of the esophagus from refluxes [50]. In a prospective multicenter study, among MII-pH parameters, only PSPW-I was an independent risk factor for refractoriness to GERD treatment (OR 1.082, 95% CI 1.022-1.146, p = 0.007).…”

“…In this regard, ineffective esophageal motility is associated with higher acid burden. However, the relationship between esophageal contractile vigor and acid burden is not univocal as the reduction in contractile vigor increases the likelihood of higher AET and chronic GERD causes esophageal motor dysfunction [49,50].…”