Mo1123 Oesophageal Intraluminal Baseline Impedance Levels in Patients With Non-Erosive Reflux Disease and in Patients With Systemic Sclerosis

Abstract

Objectives: Recent data indicate that low esophageal baseline impedance (BI) measurements may reflect the status of the esophageal mucosa. We aimed to correlate the first 30-min baseline impedance (BI) levels with the 24-h BI values in patients with heartburn and negative endoscopy. Moreover, we correlated those values with the results of 24-h impedancepH.Methods: Sixty patients with heartburn and negative endoscopy underwent 24-h impedance-pH testing off-therapy and were sub-categorized in: a) patients with abnormal acid exposure time (AET) and/or number of refluxes (NERD); b) patients with pathophysiological characteristics related to functional heartburn (FH). Impedance-pH tracks were manually evaluated to assess the mean 24-h BI (15-min time window for each hour, avoiding refluxes and swallowing) and the first 30-min BI after the placement of the probe. Moreover, AET, number of refluxes and symptom/reflux correlation (SAP) were measured. Results: NERD showed a higher mean AET (6.3±1.6% vs 0.6±0.3%, p<0.05) and reflux number (78.1±23 vs 15.4±9.8, p<0.05) compared to FH. FH had a 100% negative SAP. The first 30-min BI was lower in NERD (1126.9±144.5) than in FH (3867.5±486.8) (p<0.001). There were no differences between the 24-h BI and the 30-min BI in both groups (1126.9±144.5 vs 1101±215.4 in NERD and 3867.5±486.8 vs. 3624.4±347.5 in FH; p=n.s.). We found a strong inverse correlation between BI (24-h and 30-min) and AET or total number of reflux events (see Figure 1). Conclusions: The 30-min BI levels directly correlate with 24-h BI and inversely correlate with AET. Moreover, the 30-min BI levels appear much lower in patients with a diagnosis of NERD at impedance-pH testing.