P337 Evaluating modern reflux monitoring methods with respect to medical therapy

Introduction Multichannel impedance-pH monitoring (ZPM) and Bravo pH monitoring (BPM) are currently the gold-standard methods to objectively diagnose gastro-oesophageal reflux disease (GORD). BPM has shown to increase the diagnostic yield of GORD in patients with oesophageal hypersensitivity on ZPM1 and in negative ZPM.2 This paper addresses the treatment response of GORD when diagnosed by ZPM and BPM methods. Method This is a cross-sectional parallel study between August 2019 and September 2019 of a patient cohort who underwent ZPM or BPM methods (according to protocols3) and were treated with standard proton pump inhibitor (PPI) therapy for GORD diagnosis.4 5 Patients scored the severity of their typical reflux symptoms (heartburn [HB], regurgitation [RG] & non-cardiac chest pain [NCCP]) on a visual analogue scale whilst off PPI therapy during the reflux monitoring and again on PPI therapy 4–5 weeks later. This was used to assess for positive treatment response (when symptom severity reduced by ≥50%), symptom eradication and no symptomatic changes. Appropriate χ2 testing was employed to compare treatment response between reflux methods. Results Total of 112 patients were selected based on ZPM-GORD diagnosis (F:M=40:29, age=24–79 years) and BPM-GORD diagnosis (F:M=32:11, age=23–76 years). Overall 59/69 patients on ZPM-GORD diagnosis had positive treatment response and 20/43 patients with BPM-GORD had positive treatment response (p Complete resolution of all reflux symptoms was found in 10/69 patients from ZPM-GORD diagnosis and 2/43 patients on the BPM-GORD diagnosis (p=0.0500). When assessing each symptom, patients with ZPM-GORD diagnosis showed significantly higher prevalence in the eradication of HB (22.7% vs 5.1%, p=0.0182). Conversely patients with BPM-GORD diagnosis showed higher prevalence of no symptomatic changes in HB (4.5% vs 15.4%, p=0.0276), RG (6.1% vs 32.45, p=0.0002) and NCCP (10.3% vs 30.85, p=0.0503) during PPI therapy Conclusion The findings of this study showed that ZPM based GORD diagnosis to have higher therapeutic yield to standard PPI therapy. We recommend ZPM to be the first choice for reflux monitoring assessment and utilising BPM as complementary testing for reflux. References Rusu R, et al. BMJ Gut 2015;64;(pA487-A488). Chia C, et al. BMJ Gut 2016:65;(A115). Trudgill N, et al. Gut 2019:68;p1731–1750 Gyawali C, et al. Gut 2018;67(7);p1351–1362. Ayazi S, et al. Clin Gastroenterol Hepatol 2009;7(1):p60–7.