IMPEDANCE-PH FINDINGS CONFIRM THAT GRADE B ESOPHAGITIS PROVIDES OBJECTIVE DIAGNOSIS OF GASTROESOPHAGEAL REFLUX DISEASE

Background
Discerning whether laryngeal symptoms are related to reflux (laryngopharyngeal reflux; LPR) is a challenge. Consequently, patients see numerous specialists, undergo multiple diagnostic tests and empirically trial proton pump inhibitors (PPIs), often with inconsistent response. A clinically practical method to ascertain the likelihood of LPR among patients with laryngeal symptoms is critical. In this study we aimed to develop a clinical risk prediction score for LPR.

Methods
This prospective single center study included adult patients with laryngeal symptoms (throat clearing, sore throat, dysphonia, cough, globus, mucus in throat) referred for LPR evaluation over 3 years (07/19-08/22). Patients were categorized as LPR+ or LPR- based on presence or absence of conclusive GERD as follows: Los Angeles C/D esophagitis and/or long segment Barrett’s esophagus on endoscopy, acid exposure time (AET) ≥6% and/or ≥80 reflux events/24h on ambulatory reflux monitoring off PPI, or AET ≥2% and/or ≥40 reflux events on 24h impedance-pH on PPI.

Independent variables with p-value <0.15 for LPR+ vs LPR- informed development of permutations for multiple logistic regression models. An optimal predictive model was discriminated by area under the curve (AUC) of the receiver operating characteristics. Beta coefficients informed a weighted risk prediction model. The a priori goal was to identify a lower threshold with high confidence to rule out LPR (<20% false negative rate) and upper threshold with high confidence to rule in LPR (<20% false positive rate). Analyses were completed with R v4.2.0 (Vienna, Austria).

Results
Of 304 patients, 130 (43%) met criteria for LPR+ and 174 (57%) LPR- (Table 1). The optimal predictive model [AUC of 0.68 (95% CI 0.62, 0.74)] consisted of Cough symptom (OR 1.6 (1.0, 2.8)), Obesity/overweight (body mass index (BMI) ≥25kg/m2) (OR 1.4 (0.9, 2.3)), Globus symptom (OR 0.5 (0.3, 0.9)), Hiatal hernia ≥1cm (OR 1.9 (1.1, 3.2)), Regurgitation symptom (OR 1.9 (1.1, 3.2)), and male seX (OR 2.0 (1.2, 3.4)). The weighted prediction model, the COuGH RefluX score [AUC of 0.67 (0.61, 0.73)], ranged from -0.5 to 9.0 with a lower threshold of 3.0 (80% sensitive (95% CI 72%, 87%)) and upper threshold of 5.5 (81% specific (74%, 86%)) for LPR. Amongst the cohort 34% had a COuGH RefluX score ≤3.0, 37% had a score 3.5 to 5.0, and 29% had a score ≥5.5 (Figure 1).

Conclusions
The COuGH RefluX risk score consists of widely available clinical data (Cough, Obesity/overweight, Globus (negative predictor), presence of Hiatal hernia, Regurgitation, male seX) to enable stratification of patients with laryngeal symptoms referred for LPR evaluation as low likelihood of LPR (score ≤3.0), high likelihood of LPR (score ≥5.5), and inconclusive for LPR (score 3.5 to 5.0) for which further testing may be indicated. External validation of the COuGH RefluX score is underway.

Background: Esophageal dysmotility and reflux have been associated with restrictive lung disease (RLD), with a likely bidirectional relationship: micro-aspiration may induce pulmonary damage and restrictive chest wall mechanics may worsen esophageal function. Measures of overall reflux burden have been associated with more rapid short-term lung disease decline; however, predictors of longer-term changes and the value of proximal reflux metrics on objective testing are not well elucidated.
Aim: To determine the association between proximal reflux metrics on multichannel intraluminal impedance-pH testing (MII-pH) and change in pulmonary function test (PFT) measures in 1 year in patients with RLD.
Methods: RLD patients undergoing routine esophageal testing for pre-lung transplant evaluation were enrolled. MII-pH metrics collected included total/proximal bolus reflux episodes, bolus exposure time (BET), and total/proximal acid exposure time (AET). High-resolution manometry (HRM) measures and diagnoses per Chicago Classification v4.0 were assessed. Validated surveys were collected, including GERDQ, reflux symptom index (RSI), and global symptom severity (GSS). Lung disease severity was quantified by %-predicted FEV1 and %-predicted FVC via PFT and were evaluated at time of esophageal testing and at 1-year follow-up. Univariate (Spearman correlation) and multivariable (general linear regression) analyses were performed, adjusting for age, sex, BMI, and smoking history.
Results: 87 adults (mean age 60.8±11.6 years, 51.7% female, 83.9% interstitial lung disease) were enrolled. On univariate analyses, both proximal reflux metrics (total proximal episodes and proximal AET) were associated with a larger decline in %-predicted FEV1 and FVC, while measures of distal reflux burden (distal AET, total reflux episodes, BET) correlated with a greater decline in %-predicted FVC only (Table 1). Other reflux measures, esophageal dysmotility on HRM, and patient-reported symptom scores were not significantly associated with 1-year PFT decline. After covariate adjustment, total proximal reflux episodes (β=-0.224, p=0.016) and proximal AET (β=-9.62, p=0.001) remained independently associated with decline in %-predicted FVC (Table 2). Only proximal AET (β=-10.6, p=0.002) remained correlated with change in %-predicted FEV1, though proximal reflux episodes trended towards significance. Distal reflux burden metrics did not significantly predict 1-year decline in both %-predicted FEV1 and FVC.
Conclusion: Proximal reflux metrics on MII-pH, but not distal measures, independently predicted one-year decline in lung function in RLD. Despite their exclusion from consensus guidelines on interpretation of reflux testing, proximal reflux measures may be relevant for specific populations such as those with suspected extraesophageal reflux.

Backgrounds and aims:
The Lyon Consensus designates Los Angeles (LA) grade C/D esophagitis or acid exposure time (AET) >6% on impedance-pH monitoring (MII-pH) as conclusive for gastroesophageal reflux disease (GERD). LA grade A and B are considered inconclusive and require confirmation using MII-pH. We hypothesized that objective reflux metrics in patients with LA grade B esophagitis will provide objective GERD evidence. Accordingly, we evaluated proportions with objective GERD among symptomatic patients with LA grade A, B, and C esophagitis on endoscopy.

Methods: Consecutive patients reporting GERD symptoms underwent endoscopy and MII-pH performed off anti-reflux medications at two tertiary referral centres. Symptoms and voluptuary habits were recorded for all patients. An adequate response to PPI was defined when heartburn relief was higher than 60% on a VAS questionnaire. Patients with normal endoscopy or grade D esophagitis were excluded. Esophageal AET, number of reflux events, symptom-reflux correlation (Symptom Index, SI and Symptom Association Probability, SAP), mean nocturnal baseline impedance (MNBI, normal value >2292 ohms and chemical clearance of reflux (post-reflux swallowed induced peristaltic wave index, PSPW, normal value >61%) were calculated. Continuous data are described as median/interquartile range (Q1-Q3), and categorical data as counts and percent. Kruskal-Wallis Rank Sum Test and Pearson’s Chi-Square test were used as appropriate. Significance threshold was p<0.05.

Results:
Of 155 patients (LA grade A: 74 patients, B: 61 patients, C: 20 patients), demographics, and presentation were similar across LA grades. AET>6% was seen in 1.4%, 52.5% and 75% respectively in LA grades A, B and C. Using additional MII-pH metrics, an additional 16.2% with LA grade A, and 47.5% with LA grade B esophagitis had AET 4-6% with low MNBI and PSPW index (Figure 1); there were no additional gains using numbers of reflux episodes or symptom-reflux association metrics. Compared to LA grade C (100% conclusive GERD based on endoscopic findings), 100% of LA grade B esophagitis also had objective GERD, but only 17.6% with LA grade A esophagitis (p<0.001 compared to each). PPI response was comparable between LA grades B and C (74% and 70% respectively) but low in LA grade A (39%, p<0.001).Table 1 and 2 report clinical and MII-pH data of the three groups.

Conclusion:
Patients with LA grade B esophagitis are similar to patients with conclusive endoscopic diagnosis of GERD per Lyon Consensus in terms of MII-pH findings and treatment response, in contrast to LA grade A esophagitis. All of those with LA Grade B esophagitis diagnosed at tertiary centres had objective evidence of GERD on MII-pH. Therefore, we conclude that LA Grade B esophagitis in symptomatic patients is adequate for an objective diagnosis of GERD in tertiary referral settings.