Publications

2024

INTRODUCTION: Adenoma per colonoscopy (APC) has recently been proposed as a quality measure for colonoscopy. We evaluated the impact of a novel artificial intelligence (AI) system, compared with standard high-definition colonoscopy, for APC measurement.

METHODS: This was a US-based, multicenter, prospective randomized trial examining a novel AI detection system (EW10-EC02) that enables a real-time colorectal polyp detection enabled with the colonoscope (CAD-EYE). Eligible average-risk subjects (45 years or older) undergoing screening or surveillance colonoscopy were randomized to undergo either CAD-EYE-assisted colonoscopy (CAC) or conventional colonoscopy (CC). Modified intention-to-treat analysis was performed for all patients who completed colonoscopy with the primary outcome of APC. Secondary outcomes included positive predictive value (total number of adenomas divided by total polyps removed) and adenoma detection rate.

RESULTS: In modified intention-to-treat analysis, of 1,031 subjects (age: 59.1 ± 9.8 years; 49.9% male), 510 underwent CAC vs 523 underwent CC with no significant differences in age, gender, ethnicity, or colonoscopy indication between the 2 groups. CAC led to a significantly higher APC compared with CC: 0.99 ± 1.6 vs 0.85 ± 1.5, P = 0.02, incidence rate ratio 1.17 (1.03-1.33, P = 0.02) with no significant difference in the withdrawal time: 11.28 ± 4.59 minutes vs 10.8 ± 4.81 minutes; P = 0.11 between the 2 groups. Difference in positive predictive value of a polyp being an adenoma among CAC and CC was less than 10% threshold established: 48.6% vs 54%, 95% CI -9.56% to -1.48%. There were no significant differences in adenoma detection rate (46.9% vs 42.8%), advanced adenoma (6.5% vs 6.3%), sessile serrated lesion detection rate (12.9% vs 10.1%), and polyp detection rate (63.9% vs 59.3%) between the 2 groups. There was a higher polyp per colonoscopy with CAC compared with CC: 1.68 ± 2.1 vs 1.33 ± 1.8 (incidence rate ratio 1.27; 1.15-1.4; P < 0.01).

DISCUSSION: Use of a novel AI detection system showed to a significantly higher number of adenomas per colonoscopy compared with conventional high-definition colonoscopy without any increase in colonoscopy withdrawal time, thus supporting the use of AI-assisted colonoscopy to improve colonoscopy quality ( ClinicalTrials.gov NCT04979962).

Fernandez AM, Chan WW. Update on extraesophageal manifestations of gastroesophageal reflux. Current opinion in gastroenterology. 2024;40(4):305-313. doi:10.1097/MOG.0000000000001037

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.

Krause AJ, Kaizer AM, Carlson DA, et al. Validated Clinical Score to Predict Gastroesophageal Reflux in Patients With Chronic Laryngeal Symptoms: COuGH RefluX. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2024;22(6):1200-1209.e1. doi:10.1016/j.cgh.2024.01.021

BACKGROUND & AIMS: Discerning whether laryngeal symptoms result from gastroesophageal reflux is clinically challenging and a reliable tool to stratify patients is needed. We aimed to develop and validate a model to predict the likelihood of gastroesophageal reflux disease (GERD) among patients with chronic laryngeal symptoms.

METHODS: This multicenter international study collected data from adults with chronic laryngeal symptoms who underwent objective testing (upper gastrointestinal endoscopy and/or ambulatory reflux monitoring) between March 2018 and May 2023. The training phase identified a model with optimal receiver operating characteristic curves, and β coefficients informed a weighted model. The validation phase assessed performance characteristics of the weighted model.

RESULTS: A total of 856 adults, 304 in the training cohort and 552 in the validation cohort, were included. In the training phase, the optimal predictive model (area under the curve, 0.68; 95% CI, 0.62-0.74), was the Cough, Overweight/obesity, Globus, Hiatal Hernia, Regurgitation, and male seX (COuGH RefluX) score, with a lower threshold of 2.5 and an upper threshold of 5.0 to predict proven GERD. In the validation phase, the COuGH RefluX score had an area under the curve of 0.67 (95% CI, 0.62-0.71), with 79% sensitivity and 81% specificity for proven GERD.

CONCLUSIONS: The externally validated COuGH RefluX score is a clinically practical model to predict the likelihood of proven GERD. The score classifies most patients with chronic laryngeal symptoms as low/high likelihood of proven GERD, with only 38% remaining as indeterminate. Thus, the COuGH RefluX score can guide diagnostic strategies and reduce inappropriate proton pump inhibitor use or testing for patients referred for evaluation of chronic laryngeal symptoms.

Hiramoto B, McCarty TR, Lodhia NA, et al. Quantified Metrics of Gastric Emptying Delay by Glucagon-Like Peptide-1 Agonists: A Systematic Review and Meta-Analysis With Insights for Periprocedural Management. The American journal of gastroenterology. 2024;119(6):1126-1140. doi:10.14309/ajg.0000000000002820

INTRODUCTION: Divergent recommendations for periprocedural management of glucagon-like peptide-1 (GLP-1) receptor agonist (GLP-1 RA) medications rely on limited evidence. We performed a systematic review and meta-analysis to provide quantitative measures of gastric emptying relevant to mechanisms of weight loss and to periprocedural management of GLP-1 RA. We hypothesized that the magnitude of gastric emptying delay would be low and of limited clinical significance to procedural sedation risks.

METHODS: A protocolized search identified studies on GLP-1 RA that quantified gastric emptying measures. Pooled estimates using random effects were presented as a weighted mean difference with 95% confidence intervals (CIs). Univariate meta-regression was performed to assess the influence of GLP-1 RA type, short-acting vs long-acting mechanism of action, and duration of treatment on gastric emptying.

RESULTS: Fifteen studies met the inclusion criteria. Five studies (n = 247) utilized gastric emptying scintigraphy. Mean T 1/2 was 138.4 minutes (95% CI 74.5-202.3) for GLP-1 RA vs 95.0 minutes (95% CI 54.9-135.0) for placebo, with a pooled mean difference of 36.0 minutes (95% CI 17.0-55.0, P < 0.01, I2 = 79.4%). Ten studies (n = 411) utilized the acetaminophen absorption test, with no significant delay in gastric emptying measured by T max , area under the curve (AUC) 4hr , and AUC 5hr with GLP-1 RA ( P > 0.05). On meta-regression, the type of GLP-1 RA, mechanism of action, and treatment duration did not impact gastric emptying ( P > 0.05).

DISCUSSION: While a gastric emptying delay of ∼36 minutes is quantifiable on GLP-1 RA medications, it is of limited magnitude relative to standard periprocedural fasting periods. There were no substantial differences in gastric emptying on modalities reflective of liquid emptying (acetaminophen absorption test), particularly at time points relevant to periprocedural care.

Cai JX, Algara M, Lo WK, Kapur S, Chan WW. The Impact of Gastroesophageal Reflux Disease and Proton Pump Inhibitor Use on the Risk of Repeat Catheter Ablation for Atrial Fibrillation. Clinical and translational gastroenterology. 2024;15(6):e00717. doi:10.14309/ctg.0000000000000717

INTRODUCTION: Gastroesophageal reflux disease (GERD) has been associated with increased incidence/recurrence of atrial fibrillation (AF). However, the impact of GERD and proton pump inhibitor (PPI) therapy on outcomes of AF catheter ablation remains unclear. We aimed to assess the association between the presence of GERD and risk of repeat AF ablation, stratified by PPI therapy.

METHODS: A retrospective cohort study was conducted on patients with paroxysmal/persistent AF undergoing initial ablation in January 2011-September 2015. GERD was defined by endoscopic findings, objective reflux testing, or clinical symptoms. The association between GERD/PPI use and time to repeat ablation was evaluated by time-to-event analysis with censoring at the last clinic follow-up within 1 year.

RESULTS: Three hundred eighty-one subjects were included. Patients with GERD (n = 80) had a higher 1-year repeat ablation rate compared with those with no GERD (25% vs 11.3%, P = 0.0034). Stratifying by PPI use, patients with untreated GERD (37.5%) more likely needed repeat ablation compared with reflux-free (11.3%, P = 0.0003) and treated GERD (16.7%, P = 0.035) subjects. On multivariable Cox regression analyses, GERD was an independent risk factor of repeat ablation (hazard ratio [HR] 3.30, confidence interval [CI] 1.79-6.08, P = 0.0001). Specifically, untreated GERD was associated with earlier repeat ablation compared with no GERD (HR 4.02, CI 1.62-12.05, P = 0.0013). However, no significant difference in repeat ablation risk was noted between reflux-free and PPI-treated GERD groups.

DISCUSSION: GERD was an independent predictor for risk of repeat AF ablation within 1 year, even after controlling for major cardiovascular comorbidities and confounders. PPI therapy modulated this risk, as repeat ablation-free survival for PPI-treated GERD was noninferior to reflux-free patients.

Muftah M, Hartnett DA, Flanagan R, et al. Allergic phenotype identified on allergen testing is associated with proton pump inhibitor nonresponse in eosinophilic esophagitis. Journal of gastroenterology and hepatology. 2024;39(4):701-707. doi:10.1111/jgh.16469

BACKGROUND AND AIM: Food/environmental allergens have been associated with eosinophilic esophagitis (EoE); however, the correlation between allergy profiles and disease responsiveness to proton pump inhibitor (PPI) therapy remains unclear. We aimed to assess the association between food/environmental allergies identified on allergen testing and histologic response to PPI in patients with treatment-naive EoE.

METHODS: Adults with newly diagnosed EoE who underwent formal testing for food/environmental allergies at a tertiary center were included. All patients underwent twice-daily PPI for 8 weeks with subsequent repeat endoscopy and biopsy to assess histologic response. Patients with <15 eosinophils/hpf on post-PPI mucosal biopsies were classified as responders (PPI-r-EoE), while those with ≥15 eosinophils/hpf were nonresponders (PPI-nr-EoE).

RESULTS: Sixty-one patients met inclusion criteria (21 PPI-r-EoE vs 40 PPI-nr-EoE). Demographic, clinical, and endoscopic finding variables were similar between groups. Positive food allergen test was more prevalent among PPI-nr-EoE patients (82.5% vs 42.9%, P = 0.003). On multivariable analysis, positive food allergen testing remained an independent predictor for PPI nonresponse (aOR 0.15, CI: 0.04-0.58, P = 0.0006). Positive environmental allergen testing was highly prevalent, with no significant differences between groups (77.5% vs 95.2%, P = 0.14). However, higher number of positive environmental allergens (23.3% [≥5 allergens] vs 73.3% [<5 allergens], P = 0.003) and specific aeroallergens correlated with PPI-nr-EoE.

CONCLUSION: Positive food allergy testing and increased environmental allergens predicted lower likelihood of histologic response to PPI in EoE. Our findings support an allergic phenotype of EoE that may less likely respond to PPI therapy. Formal allergen testing may play a role in therapy selection and tailored management in EoE.

Flanagan R, Muftah M, Hiramoto B, Cai JX, Chan WW. Impact of Body Composition on Esophagogastric Junction Opening Measures: Discordant FLIP and Manometric Findings Are More Common With Increased Body Mass Index. The American journal of gastroenterology. Published online 2024. doi:10.14309/ajg.0000000000002823

INTRODUCTION: Increased intra-abdominal pressure in patients with elevated body mass index (BMI) may affect measurements of esophagogastric junction (EGJ) opening.

METHODS: Findings from adult patients who underwent both impedance planimetry with functional luminal imaging probe (FLIP) and high-resolution manometry (HRM) were compared by BMI.

RESULTS: Among patients with no EGJ outflow obstruction on HRM, abnormal EGJ classifications on FLIP were more common among those with elevated than normal BMI (61.1% vs 31.6%, P = 0.037).

DISCUSSION: Discordant results between FLIP and HRM on EGJ opening are more common in patients with elevated BMI. Body composition may impact EGJ function and measures on current testing modalities.

Muftah M, Goldin AH, Barshop K, et al. Twice-Daily Proton Pump Inhibitor Induces Higher Remission Rate in Eosinophilic Esophagitis Than Once-Daily Regimen Regardless of Total Daily Dose. The American journal of gastroenterology. 2024;119(5):991-995. doi:10.14309/ajg.0000000000002712

INTRODUCTION: The optimal proton pump inhibitor (PPI) regimen for eosinophilic esophagitis (EoE) is unclear. We compared histologic response rates of different dosing combinations.

METHODS: A total of 305 patients with newly diagnosed EoE received standard (omeprazole 20 mg daily), once-daily moderate (40 mg daily), twice-daily moderate (20 mg twice daily), or high (40 mg twice daily) dose PPI for ≥8 weeks.

RESULTS: Approximately 42.3% achieved histologic response to PPI, with higher rates for twice-daily (moderate 52.8%/high 54.3%) than once-daily (standard 11.8%/moderate 10%) dosing ( P < 0.0001). On multivariable analysis, twice-daily moderate (adjusted odds ratio 6.75, confidence interval 2.53-18.0, P = 0.0008) and high (adjusted odds ratio 12.8, confidence interval 4.69-34.8, P < 0.0001) doses independently predicted histologic response.

DISCUSSION: Twice-daily PPI is associated with higher EoE histologic response rates than once-daily regimen.

Krause AJ, Greytak M, Kaizer AM, et al. Diagnostic Yield of Ambulatory Reflux Monitoring Systems for Evaluation of Chronic Laryngeal Symptoms. The American journal of gastroenterology. 2024;119(4):627-634. doi:10.14309/ajg.0000000000002557

INTRODUCTION: Among patients with chronic laryngeal symptoms, ambulatory reflux monitoring off acid suppression is recommended to evaluate for laryngopharyngeal reflux (LPR). However, reflux monitoring systems are diverse in configuration and monitoring capabilities, which present a challenge in creating a diagnostic reference standard in these patients. This study aimed to compare diagnostic yield and performance between reflux monitoring systems in patients with chronic laryngeal symptoms.

METHODS: This multicenter, international study of adult patients referred for evaluation of LPR over a 5-year period (March 2018-May 2023) assessed and compared diagnostic yield of pathologic gastroesophageal reflux (GER+) on ambulatory reflux monitoring off acid suppression.

RESULTS: Of 813 patients, 296 (36%) underwent prolonged wireless pH, 532 (65%) underwent 24-hour pH-impedance monitoring, and 15 (2%) underwent both tests. Overall diagnostic yield for GER+ was 36% and greater for prolonged wireless pH compared with that for 24-hour pH-impedance monitoring (50% vs 27%; P < 0.01). Among 15 patients who underwent both prolonged wireless pH and 24-h pH-impedance monitoring, concordance between systems for GER+ was 40%. The most common source of discordance was strong evidence of GER+ across multiple days on prolonged wireless pH compared with no evidence of GER+ on pH-impedance.

DISCUSSION: In this multicenter international study of patients with chronic laryngeal symptoms referred for LPR evaluation, diagnostic yield of ambulatory reflux monitoring off acid suppression was 36% and rose to 50% when using wireless pH monitoring. In patients referred for chronic laryngeal symptoms, 24-hour pH-impedance monitoring may risk a low negative predictive value in patients with unproven GER+ disease.