pH Impedance Monitoring on Proton Pump Inhibitor Therapy Impacts Management Decisions in Proven GERD but Not in Unproven GERD

Background & Aims Ambulatory reflux monitoring off proton pump inhibitors (PPIs) is useful in unproven gastroesophageal reflux disease (GERD). In this prospective clinical trial, we evaluated if on-PPI pH-impedance monitoring provides value in unproven GERD. Methods Patients with typical reflux symptoms with incomplete PPI response were studied both off PPI (wireless pH monitoring) and on PPI (pH-impedance monitoring) at 2 tertiary care centers. Patients and investigators were blinded to reflux testing findings, and patients were asked to self-resume PPI for uncontrolled symptoms despite rescue antacids. Data analysis determined if on-PPI pH-impedance findings correlated with off-PPI acid exposure time (AET) or influenced PPI-related decision making. Results Of 79 patients, all 26 (32.9%) with refractory GERD metrics on-PPI had proven GERD off-PPI. In 60 patients with proven GERD off-PPI, 56.7% had no ongoing GERD on PPI. No on-PPI pH-impedance findings predicted PPI decision making among conclusive, borderline, or no reflux ( P = .872); AET ( P = .107); reflux episodes numbers ( P = .113); mean nocturnal baseline impedance ( P = .621); and reflux-symptom association categories ( P = .363). In multivariable linear and logistic regression models, off-PPI AET modestly predicted refractory GERD (odds ratio, 1.34; 95% confidence interval, 1.11–1.63; P = .003), and reflux episode numbers were borderline in predicting conclusive GERD off-PPI (odds ratio, 1.00; 95% confidence interval, 1.00–1.10; P = .04). Conclusions A minority of symptomatic patients will have refractory GERD evidence on pH-impedance monitoring on PPI; this strategy risks missing over half of the cohort with proven GERD if testing off PPI is unavailable. Our findings support documenting GERD off PPI first in PPI nonresponders and restricting on-PPI pH-impedance monitoring to identify refractory GERD only in patients with proven GERD with persisting symptoms. ClinicalTrials.gov,