Long-term wireless pH monitoring of the distal esophagus: prolonging the test beyond 48 hours is unnecessary and may be misleading

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Value of 96-hour ambulatory esophageal pH monitoring in the assessment of patients with refractory acid reflux symptoms and their response to anti-reflux diet

Ambulatory esophageal pH monitoring is a diagnostic tool in patients with heartburn and regurgitation. The aim of this study is to evaluate 96-hour esophageal pH monitoring in patients with gastroesophageal reflux disease (GERD), at baseline and under diet that impedes GER. We hypothesized that diet would potentially reduce pathologic acid exposure time (AET). Retrospective series of 88 patients with GERD undergoing wireless 96-hour pH monitoring. Two-day (48 hours) tandem periods, one on liberal, followed by another on restricted diet assessed esophageal AET. Primary end point was >30% reduction in AET while on anti-GER diet. Of the 88 patients, 16 were excluded because of probe migration. Endoscopy and biopsies assessed erosive esophagitis (EE) and Barrett's esophagus (BE), or normal esophagus. Abnormal AET (% pH < 4.0 ≥ 6) further defined nonerosive reflux disease (NERD), whereas normal AET (% pH < 4.0 < 6) with normal endoscopy defined patients as functional heartburn (FH). There were 6 patients with EE (n = 5) and BE (n = 1), 23 with NERD and 43 with FH. Anti-GER diet led to >30% reduction in AET in EE and NERD patients, but not in those with FH. Most patients (n = 43/72; 60%) had FH and could have avoided acid suppression. Furthermore, (14/23; 61%) of patients with NERD completely normalized AET with diet, potentially negating acid suppression. Ninety-six-hour esophageal pH distinguishes GERD patients from those with FH. Fifty percent of EE/BE patients and 61% of those with NERD completely normalize AET with diet. If pathologic AET occurs despite diet, acid suppression is indicated.

Optimal Wireless Reflux Monitoring Metrics to Predict Discontinuation of Proton Pump Inhibitor Therapy

INTRODUCTION

Ambulatory reflux monitoring performed off proton pump inhibitor (PPI) is the gold standard diagnostic test for nonerosive gastroesophageal reflux disease (GERD). However, the diagnostic metrics and optimal duration of monitoring are not well defined. This study evaluated the performance of multiple metrics across distinct durations of wireless reflux monitoring off PPI against the ability to discontinue PPI therapy in patients with suboptimal PPI response.

METHODS

This single-arm clinical trial performed over 4 years at 2 centers enrolled adults with troublesome GERD symptoms and inadequate response to > 8 weeks of PPI. Participants underwent 96-hour wireless pH monitoring off PPI. Primary outcome was whether the subject successfully discontinued PPI or resumed PPI within 3 weeks.

RESULTS

Of 132 participants, 30% discontinued PPI. Among multiple metrics assessed, total acid exposure time (AET) of 4.0% performed best in predicting PPI discontinuation (odds ratio 2.9 [95% confidence interval 1.4, 6.4]; P = 0.006), with other thresholds of AET and DeMeester score performing comparably. AET was significantly higher on day 1 of monitoring compared with other days, and prognostic performance significantly declined when only assessing the first 48 hours of monitoring (area under the curve for 96 hours 0.63 vs area under the curve for 48 hours 0.57; P = 0.01).

DISCUSSION

This clinical trial highlights the AET threshold of 4.0% as a high-performing prognostic marker of PPI discontinuation. 96 hours of monitoring performed better than 48 hours, in predicting ability to discontinue PPI. These data can inform current diagnostic approaches for patients with GERD symptoms who are unresponsive to PPI therapy.

Prolonged Wireless pH Monitoring in Patients With Persistent Reflux Symptoms Despite Proton Pump Inhibitor Therapy

BACKGROUND & AIMS

Wireless pH monitoring measures esophageal acid exposure time (AET) for up to 96 hours. We evaluated competing methods of analysis of wireless pH data.

METHODS

Adult patients with persisting reflux symptoms despite acid suppression (n = 322, 48.5 ± 0.9 years, 61.7% women) from 2 tertiary centers were evaluated using symptom questionnaires and wireless pH monitoring off therapy, from November 2013 through September 2017; 30 healthy adults (control subjects; 26.9 ± 1.5 years; 60.0% women) were similarly evaluated. Concordance of daily AET (physiologic <4%, borderline 4%-6%, pathologic>6%) for 2 or more days constituted the predominant AET pattern. Each predominant pattern (physiologic, borderline, or pathologic) in relation to data from the first day, and total averaged AET, were compared with other interpretation paradigms (first 2 days, best day, or worst day) and with symptoms.

RESULTS

At least 2 days of AET data were available from 96.9% of patients, 3 days from 90.7%, and 4 days from 72.7%. A higher proportion of patients had a predominant pathologic pattern (31.4%) than control subjects (11.1%; P = .03). When 3 or more days of data were available, 90.4% of patients had a predominant AET pattern; when 2 days of data were available, 64.1% had a predominant AET pattern (P < .001). Day 1 AET was discordant with the predominant pattern in 22.4% of patients and was less strongly associated with the predominant pattern compared with 48 hour AET (P = .059) or total averaged AET (P = .02). Baseline symptom burden was higher in patients with a predominant pathologic pattern compared with a predominant physiologic pattern (P = .02).

CONCLUSIONS

The predominant AET pattern on prolonged wireless pH monitoring can identify patients at risk for reflux symptoms and provides gains over 24 hours and 48 hours recording, especially when results from the first 2 days are discordant or borderline.

Ninety-Six Hour Wireless Esophageal pH Study in Patients with GERD Shows that Restrictive Diet Reduces Esophageal Acid Exposure

BACKGROUND

Prolonged (96 h) pH monitoring may explore the effect of diet on pH and symptoms in patients with GERD.

AIMS

To assess the usefulness of a 96 h esophageal pH study in patients with GER symptoms under different diets (pro- and anti-GER).

METHODS

Prospective study of 66 patients with GERD undergoing wireless 96 h pH monitoring. Two-day periods, one on liberal (pro-reflux) and another on restricted (anti-reflux) diet assessed esophageal acid exposure and symptoms. The primary end point was normalization of acid exposure time while on restricted diet. Secondary end point was a > 50% reduction in symptoms with restricted diet.

RESULTS

Normal (pH time < 4 of < 6%) was found in 34 patients (51.5%) while on the initial 48 h (liberal) diet [median % time < 4: 3.2 (95% CI, 1.9, 4.0)] and remained normal while on restricted diet [median % time < 4: 2.6 (95% CI, 0.8, 3.4)]. Abnormal acid exposure (% pH time < 4: > 6%) was found in 32 patients (48.5%) while on initial 48 h liberal diet [median % time < 4: 10.5, (95% CI 8.9, 12.6)], and decreased significantly with restricted diet [median % time < 4: 4.5 (95% CI 3.1, 7.3)] (p = 0.001), and normalized with anti-GERD diet in 21 patients (65.6%). Only 11/66 patients were candidates for proton pump inhibitor (PPI) use; 34 had either normal pH studies or normalized them with restricted diet (n = 21). Symptoms did not improve with restricted diet.

CONCLUSIONS

The 96-h esophageal pH study tests for GERD under pro- and anti-GER diets and allows minimization of PPI therapy to only 16.6% of patients.

Trajectory assessment is useful when day-to-day esophageal acid exposure varies in prolonged wireless pH monitoring

Acid exposure time commonly varies from day-to-day in prolonged wireless pH monitoring. Thus, diagnosis based on the number of days with abnormal acid burden may be misleading or inconclusive. We hypothesize that assessing longitudinal patterns of acid exposure may be diagnostically useful. Therefore, this study aims to describe acid exposure trajectories and evaluate agreement between identified trajectory patterns and conventional grouping. In this retrospective cohort study, we assessed patients with nonresponse to proton pump inhibitor therapy who underwent wireless pH monitoring (≥72 h) off therapy between August 2010 and September 2016. The primary outcome was esophageal acid exposure time. Subjects were grouped as 0, 1, 2, and 3+ days positive based on number of days with an acid exposure time >5.0%. Latent class group-based mixture model identified distinct longitudinal acid exposure trajectory groups. Of 212 subjects included 44%, 18%, 14%, and 24% had 0, 1, 2, 3+ days positive, respectively. Group-based modeling identified three significantly stable acid exposure trajectories: low (64%), middle (28%), and high (8%). Trajectory grouping and days positive grouping agreed substantially (weighted K 0.69; 95% CI: 0.63-0.76). Trajectory grouping identified 62% of subjects with conventionally inconclusive studies (one or two days positive) into the low trajectory. Agreement between trajectory groups when using three versus four days of monitoring was substantial (K 0.70; CI: 0.61-0.78). In summary, we found that patients with nonresponse to proton pump inhibitors follow three acid exposure trajectories over prolonged pH-monitoring periods: low, middle, and high. Compared to conventional day positive grouping, the trajectory modeling identified the majority of inconclusive days positive into the low trajectory group. Analyzing prolonged wireless pH data according to trajectories may be a complimentary method to conventional grouping, and may increase precision and accuracy in identifying acid burden.