Gastroesophageal Reflux Phenotypes and “Where Rome, Lyon, and Montreal Meet”

A useful review (DA Katzka et al. Clin Gastroenterol Hepatol 2020; 18: 767-76) discusses the phenotypes of gastroesophageal reflux and related disorders.   The authors note that consensus initiatives (Montreal, Rome, and Lyon) have looked at these disorders from different perspectives and their goal was to merge their perspectives.

Table 1 lists the major phenotypes:

  • Nonerosive reflux disease
  • Reflux hypersensitivity
  • Functional heartburn
  • Erosive esophagitis (low grade and high grade).  LA grade A esophagitis “can be found in approximately 6% of asymptomatic controls”
  • Barrett’s esophagus
  • Reflux chest pain syndrome
  • Regurgitation-dominant reflux disease: “need to differentiate from rumination and achalasia”
  • Laryngopharyngeal reflux
  • Chronic cough  “although reflux may contribute, it is rarely the dominant pathophysiology… more amenable to GERD therapy when accompanied by typical reflux symptoms”

Figure 1 provides a model for the pathogenesis of GERD. Figure 2 describes the relationship between reflux phenotypes and PPI responsiveness:

In those with typical reflux symptoms: 

  • esophagitis healing 84% with PPI Rx compared to 28% with placebo (NNT =1.8)
  • heartburn relief (with and without esophagitis) 56% with PPI Rx compared to 16% with placebo (NNT =4.4)
  • heartburn relief without esophagitis 40% with PPI Rx compared to 13% with placebo (NNT =3.7)
  • regurgitation relief (with and without esophagitis) 47% with PPI Rx compared to 30% with placebo (NNT =5.9)

In those with atypical reflux symptoms:

  • chest pain relief with objective GERD 74% with PPI Rx compared to 20% with placebo (NNT =1.6) (Studies used a 50% reduction in pain as opposed to complete elimination…opens the door for a greater placebo response)
  • chest pain relief without objective GERD 29% with PPI Rx compared to 23% with placebo (NNT =16.7) (Studies used a 50% reduction in pain as opposed to complete elimination…opens the door for a greater placebo response)
  • chronic cough with objective GERD 33% with PPI Rx compared to 9% with placebo (NNT =4.2)
  • chronic cough without objective GERD 31% with PPI Rx compared to 27% with placebo (NNT =25)
  • reflux laryngitis (without heartburn, complete resolution) 15% with PPI Rx compared to 16% with placebo
  • poorly-controlled asthma (without heartburn)-exacerbations per year: 2.5 with PPI Rx compared to 2.3 with placebo 
  • *references for this figure provided

Other useful points:

  • “An exception to the de-emphasizing the relationship of GERD to an extraesophageal syndrome is with lung transplantation, which …has unique considerations…the sequelae of untreated GERD …may lead to accelerated mortality from allograft injury…data have suggested that PPIs may be effective at prolonging allograft survival.”
  • The authors state that escalating PPI/antisecretory treatments for esophagitis is often effective but this approach has limited applicability for other indications and can result in overuse. “Similarly, failing to recognize the modulating effects of anxiety, hypervigilance, and visceral and central hypersensitivity on symptom severity has greatly oversimplified the problem.”

My take (borrowed in part from authors): PPIs work well for esophagitis and documented reflux; “the broad spectrum of syndromes [are] much less amenable to PPI therapy in any dose.”

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How Many Kids with Reflux Actually Have Reflux?

A terrific recent retrospective study (LB Mahoney, S Nurko, R Rosen. J Pediatr 2017; 189: 86-91) examined how often children with reflux symptoms actually have reflux.

This study reviewed 45 children ≥5 years (mean age 11.8 years) who had undergone both upper endoscopy and impedance pH study (off PPI therapy). Inclusion criteria: no erosive esophagitis. Common symptoms included heartburn, abdominal pain, chest pain, and regurgitation.

Definitions:

  • Nonerosive reflux disease –had abnormal esophageal acid exposure
  • Reflux hypersensitivity -had normal acid exposure but had a positive symptom association to acid or nonacid reflux
  • Functional heartburn -had normal acid exposure and negative symptom association

Key findings:

  • 44% had functional heartburn, 29% with reflux hypersensitivity (27% acid, 2% nonacid), 27% had nonerosive reflux disease (NERD)
  • Response to a proton pump inhibitor (PPI) was not predictive of reflux phenotype: 58% with NERD, 67% with reflux hypersensitivity, and 55% with functional heartburn. Response to PPI was stated as “at least some symptomatic improvement with PPI use.”  There was not a difference in PPI response among those who received a dose <1 mg/kg and those ≥1 mg/kg.
  • Microscopic esophagitis was present in 17% in NERD, 25% with reflux hypersensitivity, and in 20% of functional heartburn

While this study has limitations, including referral bias, it is likely that these patients are typical for many pediatric gastroenterologists. The authors note that typical patients were “patients who underwent a PPI trial but continued to have persistent symptoms.”

My take: In a pediatric gastroenterology setting, the most common reason for “reflux” is actually functional heartburn.  Thus, in those with persistent symptoms, evaluation with endoscopy and pH probe is worthwhile, especially as there has been more attention to potential risks of PPI therapy.

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Proton Pump Inhibitors Webinar

For those who missed the live NASPGHAN webinar, it is also available on demand: Link: Proton Pump Inhibitors Webinar. CME credit is available too.

Overall, this is a terrific review and intended for a high level audience. Here are a couple of key points from the talk:

  • Dr. Jennifer Lightdale introduced the webinar.  She noted that there has been a tremendous rise in the use of proton pump inhibitors (PPIs) in children over the past 15 years, including in infants.
  • Preponderance of evidence does not support use of PPIs for reducing GER symptoms or crying in infants.
  • PPIs are extremely effective at acid suppression.
  • Excellent discussion by Dr. Rachel Rosen on Nonerosive Reflux Disease (NERD) and distinguishing this entity from erosive reflux disease, hypersensitive esophagus, and functional heartburn.
  • On a microscopic level, NERD is similar to erosive reflux with microscopic inflammation and dilated intracellular spaces.
  • With regard to testing, it is recommended that for impedance studies, that acid suppression be stopped prior due to improved sensitivity/accuracy.
  • For those at odds with their pulmonologists and ENT colleagues, Dr. Ben Gold reviewed the literature on asthma, cough, and laryngeal-pharyngeal pathology related to reflux. The sensitivity of laryngoscopic findings to identify reflux is poor.  “There is insufficient evidence to recommend for OR against the use of acid suppression therapy.”
  • Dr. Jose Garza reviewed the indications for PPI use which include eosinophilic esophagitis/PPI-REE, erosive esophagitis, NSAID prophylaxis, Upper GI bleeding, and H pylori therapy.
  • Dr. Carlo DiLorenzo provided an in-depth discussion of the potential risks of PPI therapy and explained some of the context as well as absolute risks.  He noted that besides the risk of infection, particularly C difficile, other risks demonstrated in adults have not yet been confirmed in children.
  • “Prolonged acid suppression should be used only when indicated.”  Thus, management should include strategies for treatment discontinuation in the majority of those receiving PPI therapy.

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pH Probe Testing: Rumors of My Death are Premature

Several years ago, an “obituary” was written for the pH probe (Putnam PE,J Pediatr.  2010; 157(6):878-80) due to the presumed superiority of pH-impedance (pH-MII) studies in detecting gastroesophageal reflux disease (GERD)  As noted in previous blogs (see below), there have remained a number of concerns with the assumption that pH-MII is an improvement over pH studies without impedance.  Several recent studies elaborate on those concerns:

  1. Cheng F-K F, et al. Clin Gastroenterol Hepatol 2015; 13: 867-73
  2. Patel A, et al. Clin Gastroenterol Hepatol 2015; 13: 884-91
  3. Vaezi MF. Clin Gastroenterol Hepatol 2015; 13: 892-94 (editorial)

In the first study, the authors identified 221 patients and retrospectively reviewed GERD testing from 2006-2011.  Prior to testing, 97% had received prescribed PPIs before testing; however, PPIs were discontinued for at least 1 week prior to evaluation which included upper endoscopy, esophageal manometry, and pH-MII.

  • 21 (10%) had erosive esophagitis
  • 61 (27%) had nonerosive reflux disease with increased pH
  • 18 (8%) had nonerosive reflux disease with abnormal impedance
  • 30 (14%) had hypersensitive esophagus
  • 18 (8%) had functional heartburn
  • 30 (14%) had other functional disorders
  • 43 (19%) were undetermined

Thus, this retrospective study showed that the majority (roughly 2/3rds) of patients with GERD symptoms on PPI therapy did not have GERD based on objective testing.  The authors chose to test off PPI therapy “because we postulated that the pretest probability of GERD diagnosis was low, primarily given their lack of response to PPI.”

In the second study, 187 subjects (≥18 years) underwent pH-MII testing in a prospective study from 2005-2010.  49.7% were tested off proton pump inhibitor therapy. Abnormal acid exposure time consistently predicted symptomatic outcome.  The authors note that performing pH-MII off PPI therapy best predicts response to antireflux therapy

In the third reference, the editorial which commented on the second, there are several useful points:

  • “There is little doubt that pH-impedance testing provides a more sensitive means of comprehensively identifying reflux events in a given patient. However, to date, studies have failed to demonstrate that it provides any significant additional clinical benefit.”
  • “Caution must be exercised when incorporating the added objective data from non-acidic or weakly acidic reflux events into treatment decision-making…Studies including Patel et al have not shown that knowledge regarding continued non-acid or weakly acid reflux events alter patient outcomes.”
  • “Wireless pH testing is generally better tolerated and provides longer measurement duration”
  • The use of symptom indices are too subjective.  “Recent data question the use of these indices especially in those with refractory symptoms and minimal reflux by pH or impedance testing.”  SI and SAP could be altered by chance occurrences….”A colleague expert in esophageal diseases …once said: “I know the tests are no good but I don’t know what else to use.'”
  • “Let us simplify our approach on the basis of available data and not use measures that we know are suboptimal at best.”

After looking at these studies and the previous pH probe obituary, I’m reminded of a story.  Several religious leaders were asked what they wanted someone to say at their funeral.  A few stated that they wanted their congregants/flock to comment on their values, like piety and charity.  However, one said, “I hope they say, ‘Look he’s moving!'”

Bottomline: There is no reliable evidence that pH-MII testing improves outcomes over conventional pH probe testing. In fact, the use of pH-MII, by lowering the specificity for GERD, could have a detrimental effect.  With either test, holding acid suppression for 1 week (with PPIs) is likely to be helpful in interpreting the results.

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Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications/diets (along with potential adverse effects) should be confirmed by prescribing physician/nutritionist.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

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Zoo Atlanta