Diagnosis of Esophageal Motility Disorders: Esophageal Pressure Topography vs. Conventional Line Tracing

OBJECTIVES: Enhanced characterization of esophageal peristaltic and sphincter function provided by esophageal pressure topography (EPT) offers a potential diagnostic advantage over conventional line tracings (CLT). However, high-resolution manometry (HRM) and EPT require increased equipment costs over conventional systems and evidence demonstrating a significant diagnostic advantage of EPT over CLT is limited. Our aim was to investigate whether the inter-rater agreement and/or accuracy of esophageal motility diagnosis differed between EPT and CLT. METHODS: Forty previously completed patient HRM studies were selected for analysis using a customized software program developed to perform blinded independent interpretation in either EPT or CLT (six pressure sensors) format. Six experienced gastroenterologists with a clinical focus in esophageal disease (attendings) and six gastroenterology trainees with minimal manometry experience (fellows) from three academic centers interpreted each of the 40 studies using both EPT and CLT formats. Rater diagnoses were assessed for inter-rater agreement and diagnostic accuracy, both for exact diagnosis and for correct identification of a major esophageal motility disorder. RESULTS: The total group agreement was moderate (kappa=0.57; 95% CI: 0.56-0.59) for EPT and fair (kappa=0.32; 0.30-0.33) for CLT. Inter-rater agreement between attendings was good (kappa=0.68; 0.65-0.71) for EPT and moderate (kappa=0.46; 0.43-0.50) for CLT. Inter-rater agreement between fellows was moderate (kappa=0.48; 0.45-0.50) for EPT and poor to fair (kappa=0.20; 0.17-0.24) for CLT. Among all raters, the odds of an incorrect exact esophageal motility diagnosis were 3.3 times higher with CLT assessment than with EPT (OR: 3.3; 95% CI: 2.4-4.5; P<0.0001), and the odds of incorrect identification of a major motility disorder were 3.4 times higher with CLT than with EPT (OR: 3.4; 2.4-5.0; P<0.0001). CONCLUSIONS: Superior inter-rater agreement and diagnostic accuracy of esophageal motility diagnoses were demonstrated with analysis using EPT over CLT among our selected raters. On the basis of these findings, EPT may be the preferred assessment modality of esophageal motility.