Lower prevalence of gastroesophageal reflux disease in patients with noncardiac chest pain on opiates: a cross-sectional study

: Opiates can cause heartburn and spastic esophageal dysmotility but their role in noncardiac chest pain (NCCP) is not known. Our aim was to characterize opiate effects on esophageal function using esophageal pH monitoring and high-resolution manometry (HREM) in these patients.We performed a cross sectional study of opiate users with NCCP who underwent HREM and esophageal pH study from 2010 to 2017 using opiate nonusers as a comparison group. Demographic data, symptoms, opiate use, endoscopic findings, esophageal pH study parameters, and HREM data were abstracted.Thirty three patients with NCCP on opiates were compared to 144 opiate non-users. Compared to opiate nonusers, opiate users had lower total acid exposure (2.3% vs. 3%, P = 0.012), lower upright acid exposure (1.2% vs. 3.1%, P = 0.032) and lower DeMeester score (6.5 vs. 12.7, P = 0.016). Opiate users also had higher lower esophageal sphincter integrated relaxation pressure (LES-IRP) (7.0 mm Hg [2.2, 11.7] vs. 3.7 mm Hg [1.1, 6.2] P = 0.011) and greater mean distal contractile integral (DCI) (2575 mm.Hg.s.cm [1134, 4466] vs. 1409 mm.Hg.s.cm [796, 3003] P = 0.03) than opiate non-users. The prevalence of hypertensive motility disorders (15.2% vs. 11.1%) and achalasia (12.1% vs. 2.1%) was higher in opiate users (P = 0.039) but did not reach significance on multivariate analysis.In patients presenting with NCCP, opiate users had lower esophageal acid exposure compared to opiate nonusers. This might be due to higher LES pressures preventing reflux and higher DCI leading to more rapid acid esophageal clearance.