383. LOSS OF PERISTALTIC RESERVE DETERMINED BY MULTIPLE RAPID SWALLOWS CORRELATES WITH DYSPHAGIA AND POOR BOLUS TRANSIT IN INEFFECTIVE ESOPHAGEAL MOTILITY

Abstract Introduction Ineffective esophageal motility (IEM) is a common finding on high resolution esophageal manometry (HRM) and is often of unclear clinical significance as its impact on dysphagia and bolus transit is variable. Multiple rapid swallow (MRS) testing is a provocative maneuver performed during HRM that assesses peristaltic reserve, documented by the presence of contractile augmentation (defined by contractile vigor after MRS greater than that seen with single swallows). Lack of augmentation after MRS is associated with dysphagia after anti-reflux surgery. To date, no studies have evaluated the impact of peristaltic reserve on dysphagia and bolus transit in IEM patients. Methods Retrospective review of 159 patients with Chicago classification 4.0 IEM. 52 patients were excluded due to prior esophageal surgery, technically inadequate MRS, or concomitant esophagogastric junction outflow obstruction. Demographics and brief esophageal dysphagia questionnaire (BEDQ) results were obtained from a prospectively maintained database. MRS and bolus transit data were analyzed using a commercially available software. Impedance analysis documented complete versus incomplete bolus transit. Augmentation was defined as the ratio of post-MRS DCI to mean single swallow DCI > 1. Fisher's exact test for continuous data and linear model ANOVA were used to assess for statistical significance. Results 107 IEM patients were included, 46 of them had loss of peristaltic reserve (no augmentation on MRS). Compared to IEM patients with augmentation, those without augmentation had more severe dysphagia documented by higher mean BEDQ score (6.8 versus 4.8, p= 0.045), and increased rates of impaired bolus transit (73% versus 55%, p-= 0.013). Discussion IEM patients without augmentation on MRS have more severe dysphagia and more frequent incomplete bolus clearance. These findings support adding MRS response to the diagnosis of IEM or using it to describe a subset of patients with more severe disease.