Comparative study between the values of the contractile integral of the esophagogastric junction in the upright position versus the supine measurement as a predictor of gastroesophageal reflux disease.

The contractile integral of the esophagogastric junction (EGJ-CI) is a high-resolution esophageal manometry (HRM) tool designed to assess EGJ barrier function. However, there is scarce data on the best position to measure the EGJ-CI. We aimed to determine the upright and supine EGJ-CI values best associated with abnormal acid exposure time (AET) and compare their diagnostic performance. Our study included patients with typical gastroesophageal reflux disease (GERD) symptoms who underwent esophageal impedance pH monitoring and HRM. The diagnosis of GERD was defined as an AET > 6%. The cutoff points of the EGJ-CI in upright and supine position that better predict the diagnosis of GERD were obtained by receiver operating characteristic curves. The values of the areas under the curve (AUC) were compared. We included 100 consecutive patients. The median age was 52 (range: 41-59) years. Sixty-seven (67%) patients were female. The median AET was 2.40% (range: 0.52-5.60). Twenty-three (23.0%) patients had GERD. The EGJ-CI value in upright position that correlated best with GERD was ≤34.0, with a sensitivity of 95.7%, specificity of 40.3%, and AUC of 0.719. The supine EGJ-CI value was ≤36.0, with a sensitivity of 82.6%, specificity of 40.3%, and AUC of 0.617. The difference between the AUCs was 0.102 (P = 0.038). Our findings suggest that EGJ-CI measurement should be performed in the upright position as it has a higher yield in the detection of GERD. However, studies with a larger sample are needed to corroborate our findings.