Novel Advanced Impedance Metrics on Impedance-pH Testing Predict Lung Function Decline in Idiopathic Pulmonary Fibrosis

Update on extraesophageal manifestations of gastroesophageal reflux

PURPOSE OF REVIEW

Symptoms/complications related to extraesophageal reflux (EER) are increasingly prevalent presentations and pose significant challenges for clinicians. We summarize and discuss clinical advances and developments in pathophysiology, testing and treatment algorithms of upper/lower airway manifestations of EER.

RECENT FINDINGS

Growing evidence supports likely multifactorial causes of laryngeal symptoms, including EER, oropharyngeal pathologies, allergic conditions, and cognitive-affective processes (brain-larynx interaction). Diagnostic paradigm for laryngopharyngeal reflux (LPR) is shifting towards a personalized approach with noninvasive strategies/prediction tools to risk-stratify patients for upfront reflux testing over empiric acid suppression trials. Management should be multipronged to include antireflux therapies and treatments targeting other causes. Lower airway complications of EER may result in lung dysfunction and poor transplant outcomes. Esophageal symptoms are often absent and routine esophageal/reflux testing to guide timely antireflux therapies may lead to improved outcomes. Modalities that leverage impedance technology may be important, given the potential role of nonacidic reflux. Novel impedance-based metrics such as mean nocturnal baseline impedance and postreflux swallow-induced peristaltic wave index may provide adjunctive diagnostic values.

SUMMARY

Standardized approach to diagnosis/management of EER should include multidisciplinary care teams and consider different phenotypes, nonreflux contributors, and the complex gut-airway relationships. Prompt antireflux therapies after careful candidate selection may improve outcomes of these airway complications.

The impact of lung transplantation on esophageal motility and inter-relationships with reflux and lung mechanics in patients with restrictive and obstructive respiratory disease

BACKGROUND

For many patients with lung disease the only proven intervention to improve survival and quality of life is lung transplantation (LTx). Esophageal dysmotility and gastroesophageal reflux (GER) are common in patients with respiratory disease, and often associate with worse prognosis following LTx. Which, if any patients, should be excluded from LTx based on esophageal concerns remains unclear. Our aim was to understand the effect of LTx on esophageal motility diagnosis and examine how this and the other physiological and mechanical factors relate to GER and clearance of boluses swallowed.

METHODS

We prospectively recruited 62 patients with restrictive (RLD) and obstructive (OLD) lung disease (aged 33-75 years; 42 men) who underwent high resolution impedance manometry and 24-h pH-impedance before and after LTx.

KEY RESULTS

RLD patients with normal motility were more likely to remain normal (p = 0.02), or if having abnormal motility to change to normal (p = 0.07) post-LTx than OLD patients. Esophageal length (EL) was greater in OLD than RLD patients' pre-LTx (p < 0.001), reducing only in OLD patients' post-LTx (p = 0.02). Reduced EL post-LTx associated with greater contractile reserve (r = 0.735; p = 0.01) and increased likelihood of motility normalization (p = 0.10). Clearance of reflux improved (p = 0.01) and associated with increased mean nocturnal baseline impedance (p < 0.001) in RLD but not OLD. Peristaltic breaks and thoraco-abdominal pressure gradient impact both esophageal clearance of reflux and boluses swallowed (p < 0.05).

CONCLUSIONS AND INFERENCES

RLD patients are more likely to show improvement in esophageal motility than OLD patients post-LTx. However, the effect on GER is more difficult to predict and requires other GI, anatomical and pulmonary factors to be taken into consideration.

Endoscopic reflux esophagitis and decline in pulmonary function in nonsmokers: A retrospective cohort study

BACKGROUND

The association between reflux esophagitis and pulmonary function remains controversial. Thus, evaluating the relationship between endoscopic reflux esophagitis and changes in pulmonary function over time in a nonsmoking population is an important clinical issue.

METHODS

In this single-center retrospective cohort study, a medical examination database at Kameda Medical Center Makuhari was employed to identify nonsmokers who underwent upper gastrointestinal endoscopy and spirometry in 2010 and were followed up in 2015. Gastroenterologists carefully double-checked the diagnosis of reflux esophagitis. Multiple linear regression analyses were performed to compare the decline in the percentage of predicted vital capacity (%VC), forced vital capacity (%FVC), and forced expiratory volume in 1 s (%FEV1) between participants with reflux esophagitis and those without. Furthermore, using multivariable logistic regression analyses, we evaluated the factors associated with rapid decline in %VC, %FVC, and %FEV1, which is defined as a decrease of >10% in each parameter over the 5-year observation period.

RESULTS

We identified 3098 eligible subjects, including 72 and 44 participants who had a Los Angeles classification grade A and B-C (severe) reflux esophagitis in 2010, respectively. The decline in %VC was significantly larger in the participants with severe reflux esophagitis than in the control subjects (standardized coefficient, -0.037; 95% confidence interval, -0.071 to -0.004). Moreover, reflux esophagitis was significantly associated with a rapid decline in %VC and %FVC but not in %FEV1 (P for trend: 0.009, 0.009, and 0.276, respectively).

CONCLUSIONS

Severe reflux esophagitis among nonsmokers had clinical disadvantages in terms of a decline in %VC.

Updates to the modern diagnosis of GERD: Lyon consensus 2.0

The Lyon Consensus provides conclusive criteria for and against the diagnosis of gastro-oesophageal reflux disease (GERD), and adjunctive metrics that consolidate or refute GERD diagnosis when primary criteria are borderline or inconclusive. An international core and working group was assembled to evaluate research since publication of the original Lyon Consensus, and to vote on statements collaboratively developed to update criteria. The Lyon Consensus 2.0 provides a modern definition of actionable GERD, where evidence from oesophageal testing supports revising, escalating or personalising GERD management for the symptomatic patient. Symptoms that have a high versus low likelihood of relationship to reflux episodes are described. Unproven versus proven GERD define diagnostic strategies and testing options. Patients with no prior GERD evidence (unproven GERD) are studied using prolonged wireless pH monitoring or catheter-based pH or pH-monitoring off antisecretory medication, while patients with conclusive GERD evidence (proven GERD) and persisting symptoms are evaluated using pH-impedance monitoring while on optimised antisecretory therapy. The major changes from the original Lyon Consensus criteria include establishment of Los Angeles grade B oesophagitis as conclusive GERD evidence, description of metrics and thresholds to be used with prolonged wireless pH monitoring, and inclusion of parameters useful in diagnosis of refractory GERD when testing is performed on antisecretory therapy in proven GERD. Criteria that have not performed well in the diagnosis of actionable GERD have been retired. Personalisation of investigation and management to each patient's unique presentation will optimise GERD diagnosis and management.

Abnormal bolus reflux on impedance-pH testing independently predicts 3-year pulmonary outcome and mortality in pulmonary fibrosis

BACKGROUND AND AIM

Gastroesophageal reflux has been associated with idiopathic pulmonary fibrosis (IPF), although the directionality of the relationship has been debated. Data on the value of objective reflux measures in predicting IPF disease progression and mortality remain limited. We aimed to evaluate the association between multichannel intraluminal impedance and pH testing (MII-pH) and 3-year pulmonary outcomes in IPF patients.

METHODS

This was a retrospective cohort study of adults with IPF who underwent pre-lung transplant MII-pH off acid suppression at a tertiary center. Patients were followed for 3 years after MII-pH for poor pulmonary outcomes (hospitalization for respiratory exacerbation or death). A secondary analysis was performed using mortality as outcome of interest. Time-to-event analyses using Kaplan-Meier and Cox regression were performed to evaluate associations between MII-pH and poor outcomes.

RESULTS

One hundred twenty-four subjects (mean age = 61.7 ± 8 years, 62% male) were included. Increased bolus exposure time (BET) on MII-pH was associated with decreased time to poor pulmonary outcomes and death (log-ranked P-value = 0.017 and 0.031, respectively). On multivariable Cox regression analyses controlling for potential confounders including age, sex, smoking history, body mass index, proton pump inhibitor use, baseline pulmonary function, and anti-fibrotic therapy, increased BET was an independent predictor for poor pulmonary outcomes [hazard ratio 3.18 (95% confidence interval: 1.25-8.09), P = 0.015] and mortality [hazard ratio 11.3 (95% confidence interval: 1.37-63.9), P = 0.025] over 3 years.

CONCLUSIONS

Increased BET on MII-pH is an independent predictor of poor pulmonary outcomes and mortality over 3 years in IPF patients. These findings also support a role for gastroesophageal reflux in IPF disease progression and the potential impact of routine reflux testing and treatment.

Acid exposure time is sensitive for detecting gastroesophageal reflux disease and is associated with long-term survival after lung transplant

Gastroesophageal reflux disease (GERD) is common in patients who have undergone lung transplantation and is associated with poorer outcomes, but guidelines are lacking to direct management strategies in this population. We assessed the diagnostic yield of impedance metrics compared to pH-metry alone for detecting GERD among lung transplant recipients and evaluated their association with clinical outcomes. We performed a retrospective cohort study of consecutive patients who underwent lung transplantation. Demographic data, acid exposure time (AET), number of reflux episodes, mean nocturnal baseline impedance (MNBI), post-reflux swallowing-induced peristaltic wave index (PSPWI), and clinical outcomes including mortality were collected. The relationship between GERD metrics and clinical outcomes was assessed using Wilcoxon signed-rank test and Fisher's exact test as appropriate. Of the 76 patients studied, 29 (38%) had GERD based on abnormal AET after lung transplantation. One (1.3%) patient had GERD based on elevated number of reflux episodes and abnormal distal MNBI detected GERD in 19 (26%) patients, resulting in 62% sensitivity and 94% specificity. Two (2.6%) patients had normal PSPWI. Patients with low distal MNBI had significantly decreased forced expiratory volume in 1 second (FEV1) at 3-year posttransplant compared to those without low distal MNBI (P = 0.03). Three-year survival was significantly worse among patients with elevated AET (66.7% vs. 89.1%, P = 0.03) but not with low distal MNBI (68.4% vs. 84.3%, P = 0.18). Abnormal AET is more sensitive for detecting GERD than other reflux metrics studied and is associated with survival, suggesting pH-metry alone may be sufficient to guide GERD management after lung transplant.

AGA Clinical Practice Update on the Diagnosis and Management of Extraesophageal Gastroesophageal Reflux Disease: Expert Review

DESCRIPTION

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update is to review the available evidence and expert advice regarding the clinical management of patients with suspected extraesophageal gastroesophageal reflux disease.

METHODS

This article provides practical advice based on the available published evidence including that identified from recently published reviews from leading investigators in the field, prospective and population studies, clinical trials, and recent clinical guidelines and technical reviews. This best practice document is not based on a formal systematic review. The best practice advice as presented in this document applies to patients with symptoms or conditions suspected to be related to extraesophageal reflux (EER). This expert review was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPUC and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. These Best Practice Advice (BPA) statements were drawn from a review of the published literature and from expert opinion. Because systematic reviews were not performed, these BPA statements do not carry formal ratings of the quality of evidence or strength of the presented considerations. BEST PRACTICE ADVICE 1: Gastroenterologists should be aware of potential extraesophageal manifestations of gastroesophageal reflux disease (GERD) and should inquire about such disorders including laryngitis, chronic cough, asthma, and dental erosions in GERD patients to determine whether GERD may be a contributing factor to these conditions. BEST PRACTICE ADVICE 2: Development of a multidisciplinary approach to extraesophageal (EER) manifestations is an important consideration because the conditions are often multifactorial, requiring input from non-gastroenterology (GI) specialties. Results from diagnostic testing (ie, bronchoscopy, thoracic imaging, laryngoscopy, etc) from non-GI disciplines should be taken into consideration when gastroesophageal reflux (GER) is considered as a cause for extraesophageal symptoms. BEST PRACTICE ADVICE 3: Currently, there is no single diagnostic tool that can conclusively identify GER as the cause of EER symptoms. Determination of the contribution of GER to EER symptoms should be based on the global clinical impression derived from patients' symptoms, response to GER therapy, and results of endoscopy and reflux testing. BEST PRACTICE ADVICE 4: Consideration should be given toward diagnostic testing for reflux before initiation of proton pump inhibitor (PPI) therapy in patients with potential extraesophageal manifestations of GERD, but without typical GERD symptoms. Initial single-dose PPI trial, titrating up to twice daily in those with typical GERD symptoms, is reasonable. BEST PRACTICE ADVICE 5: Symptom improvement of EER manifestations while on PPI therapy may result from mechanisms of action other than acid suppression and should not be regarded as confirmation for GERD. BEST PRACTICE ADVICE 6: In patients with suspected extraesophageal manifestation of GERD who have failed one trial (up to 12 weeks) of PPI therapy, one should consider objective testing for pathologic GER, because additional trials of different PPIs are low yield. BEST PRACTICE ADVICE 7: Initial testing to evaluate for reflux should be tailored to patients' clinical presentation and can include upper endoscopy and ambulatory reflux monitoring studies of acid suppressive therapy. BEST PRACTICE ADVICE 8: Testing can be considered for those with an established objective diagnosis of GERD who do not respond to high doses of acid suppression. Testing can include pH-impedance monitoring while on acid suppression to evaluate the role of ongoing acid or non-acid reflux. BEST PRACTICE ADVICE 9: Alternative treatment methods to acid suppressive therapy (eg, lifestyle modifications, alginate-containing antacids, external upper esophageal sphincter compression device, cognitive-behavioral therapy, neuromodulators) may serve a role in management of EER symptoms. BEST PRACTICE ADVICE 10: Shared decision-making should be performed before referral for anti-reflux surgery for EER when the patient has clear, objectively defined evidence of GERD. However, a lack of response to PPI therapy predicts lack of response to anti-reflux surgery and should be incorporated into the decision process.

Relationship Between Esophageal Disease and Pulmonary Fibrosis

Esophageal disorders are prevalent among patients with chronic lung diseases, including idiopathic pulmonary fibrosis (IPF). Gastroesophageal reflux disease (GERD) has been associated with IPF prevalence, severity, and respiratory decline. The pathophysiologic relationship between GERD and IPF is likely bidirectional, with aspiration of refluxate leading to lung inflammation and fibrosis, while the restrictive pulmonary physiology may contribute to altered transdiaphragmatic pressure gradient and increased reflux. Esophageal symptoms are frequently absent and do not predict esophageal dysfunction or pathologic reflux in patients with IPF, and objective diagnostic tools including upper endoscopy, ambulatory reflux monitoring, and high-resolution manometry are often needed. Impedance-based testing that identifies both weakly/non-acidic and acid reflux may provide important additional diagnostic value beyond pH-based acid testing alone. Novel metrics and maneuvers, including advanced impedance measures on impedance-pH study and provocative testing on HRM, may hold promise to future diagnostic advancements. The main treatment options include medical therapy with acid suppressants and anti-reflux surgery, although their potential benefits in pulmonary outcomes of IPF require further validations. Future directions of research include identifying phenotypes of IPF patients who may benefit from esophageal testing and treatment, determining the optimal testing strategy and protocol, and prospectively assessing the value of different esophageal therapies to improve outcomes while minimizing risks. This review will discuss the pathophysiology, evaluation, and management of esophageal diseases, particularly GERD, in patients with IPF, as informed by the most recent publications in the field, in hopes of identifying targets for future study and research.

Editorial: Lyon consensus metrics-towards personalised diagnosis of non-erosive reflux disease: Authors' reply

This article is linked to Frazzoni et al papers. To view these articles, visit https://doi.org/10.1111/apt.16838 and https://doi.org/10.1111/apt.16899

Reflux Monitoring in Lung Disease: Is There a Better Metric than Esophageal Acid Exposure Time?

Ambulatory reflux monitoring can be performed with either a telemetry capsule to monitor for esophageal acid exposure alone for a period of 48-96 hours, and a 24 hour catheter based impedance/pH study which is most valuable for evaluating patients with objective evidence of GERD who are incompletely relieved with proton pump inhibitors. Some would consider catheter-based impedance/pH as the "best" test to evaluate patients with extraesophageal symptoms including suspected pulmonary complications of GERD. This editorial provides comment on the use of novel advanced metrics, mean nocturnal baseline impedance and post-reflux induced-swallow peristaltic wave index in analysis of these studies.