Tu1975 The Impairment of Proximal Esophageal Mucosal Integrity May Play a Causative Role in Patients With Noncardiac Chest Pain

Abstract

OBJECTIVES: Noncardiac chest pain (NCCP) is defined as recurrent chest pain which does not originate from cardiac cause. Gastroesophageal reflux disease (GERD) is themost common cause of NCCP. However, there are patients presenting NCCP whose symptom is not related with GERD. This study aims to evaluate novel mechanism of non-GERD-related NCCP using high-resolution impedance manometry (HRIM) and 24-hour multichannel intraluminal impedance-pH (MII-pH) testing. PATIENTS AND METHODS: This retrospective study was conducted at Samsung Medical Center between June 2011 and December 2012. A total of 77 NCCP patients and 14 healthy volunteers (control group) were included. The subjects underwent upper endoscopy, esophageal HRIM and 24-hr MII-pH testing. According to the presence of erosive esophagitis and/or pathologic acid exposure, patients were divided into GERD-related group and non-GERD-related group. We measured mean esophageal baseline intraluminal impedances and investigated esophageal motility disorders and/or peristaltic abnormalities. The mean baseline intraluminal impedance was measured at distal and proximal esophagus, 3 cm and 17 cm above the lower esophageal sphincter. The esophageal motility disorders and peristaltic abnormalities were determined by Chicago classification. RESULTS: Among 77 NCCP patients, 16 (11.7%) were included in GERD-related group and 61 (88.3%) were included in non-GERD-related group. The distal mean baseline intraluminal impedance did not differ between NCCP patients and control group. However, the proximal mean baseline intraluminal impedance was lower in NCCP patients than in control group (2463±631 vs. 3739±486 V, P<0.001). In subgroup analysis, the distal mean baseline intraluminal impedance was lower only in GERD-related group than in non-GERD-related NCCP group (1924±802 vs. 2666±804 V, P<0.001) and control group (1924±802 vs. 3739±486 V, P=0.02). There was no difference in distal mean baseline intraluminal impedance between non-GERD-related group and control group. On the contrary, the proximal mean baseline intraluminal impedance was lower both in GERD-related (2391±711 vs. 3739±486V, P<0.001) and non-GERD-related group (2482±614 vs. 3739±486V, P<0.001) than in control group. The proximal mean baseline intraluminal impedance did not differ between GERD-related and non-GERD-related group. There was no difference in esophageal motility disorders, peristaltic abnormalities or impaired bolus transit among these groups. CONCLUSIONS: The proximal esophageal mucosal integrity impairment may play a causative role in patients with non-GERD-related NCCP. The proximal mucosal integrity seems to be impaired by another mechanism rather than esophageal hypomotility and impaired bolus transit.