Weak peristalsis with large breaks in chronic cough: association with poor esophageal clearance

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.

GERD-related chronic cough: Possible mechanism, diagnosis and treatment

GERD, or gastroesophageal reflux disease, is a prevalent medical condition that affects millions of individuals throughout the world. Chronic cough is often caused by GERD, and chronic cough caused by GER is defined as GERD-related chronic cough (GERC). It is still unclear what the underlying molecular mechanism behind GERC is. Reflux theory, reflex theory, airway allergies, and the novel mechanism of esophageal motility disorders are all assumed to be linked to GERC. Multichannel intraluminal impedance combined with pH monitoring remains the gold standard for the diagnosis of GERC, but is not well tolerated by patients due to its invasive nature. Recent discoveries of new impedance markers and new techniques (mucosal impedance testing, salivary pepsin, real-time MRI and narrow band imaging) show promises in the diagnosis of GERD, but the role in GERC needs further investigation. Advances in pharmacological treatment include potassium-competitive acid blockers and neuromodulators (such as Baclofen and Gabapentin), prokinetics and herbal medicines, as well as non-pharmacological treatments (such as lifestyle changes and respiratory exercises). More options have been provided for the treatment of GERC other than acid suppression therapy and anti-reflux surgery. In this review, we attempt to review recent advances in GERC mechanism, diagnosis, and subsequent treatment options, so as to provide guidance for management of GERC.

Nonachalasic esophageal motor disorders, from diagnosis to therapy

INTRODUCTION

Investigations conducted using conventional manometry and, recently, using high-resolution manometry (HRM), allowed us to explore the field of esophageal motility and understand the potential link between motor features and gastroesophageal reflux disease (GERD) pathogenesis. The management of patients with nonachalasic esophageal motor disorders is often challenging, due to the clinical heterogeneous presentation and the multifactorial nature of the mechanisms underlying symptoms.

AREAS COVERED

Several studies, carried out using HRM, have better interpreted the esophageal motor function in patients with esophagogastric junction outflow obstruction (EGJOO), distal esophageal spasm (DES), hypertensive esophagus, and hypomotility disorders. Moreover, HRM studies have shown a direct correlation between reduced esophageal motility, disruption of the esophagogastric junction, and gastroesophageal reflux burden.

EXPERT OPINION

Pathogenesis, clinical presentation, diagnosis, and treatment of nonachalasic esophageal motor disorders still represent a challenging area, requiring future evaluation by multicenter outcome studies carried out in a large cohort of patients and asymptomatic subjects. However, we believe that an accurate clinical, endoscopic, and HRM evaluation is, nowadays, helpful in addressing patients with nonachalasic esophageal motor disorders to optimal treatment options.

Heartburn as a Marker of the Success of Acid Suppression Therapy in Chronic Cough

Purpose

Gastro-oesophageal reflux disease (GORD) is commonly thought to play an important role in chronic cough and patients are often empirically treated with acid suppression therapy. We sought to investigate the response rate to acid suppression treatment in patients with and without heartburn attending two specialist cough clinics.

Methods

A retrospective review of 558 consecutive patients referred to two specialist cough clinics was performed (UK and USA). Patients who were treated with acid suppression were included and their documented response to treatment was collected. Binary logistic regression was used to ascertain the value of reported heartburn in predicting the response of chronic cough to acid suppression therapy.

Results

Of 558 consecutive referrals, 238 patients were excluded due to missing data or cough duration of < 8 weeks. The remaining 320 patients were predominantly female (76%), with mean age 61 yrs (± 13) and 96.8% non-smokers, with chronic cough for 36 (18–117) months. Of 72 patients with heartburn, 20 (28%) noted improvement in their cough with acid suppression, whereas of 248 without heartburn, only 35 (14%) responded. Patients reporting heartburn were 2.7 (95% C.I. 1.3–5.6) times more likely to respond to acid suppression therapy (p = 0.007).

Conclusion

In specialist cough clinics, few patients report a response of their chronic cough to acid suppression therapy. Nonetheless, heartburn is a useful predictor substantially increasing the likelihood of benefit.

The Results From Up-Front Esophageal Testing Predict Proton Pump Inhibitor Response in Patients With Chronic Cough

INTRODUCTION

The clinical management of chronic cough patients is challenging, and their response to proton pump inhibitors (PPIs) is considered as unsatisfactory. Few data concerning the association between impedance-pH variables and PPI response in these patients are available. Mean nocturnal baseline impedance (MNBI) and postreflux swallow-induced peristaltic wave (PSPW) index increase the diagnostic yield of impedance-pH in gastroesophageal reflux disease.

METHODS

Demographic, clinical, and endoscopy findings; impedance-pH; and high-resolution manometry tracings from consecutive patients assessed for cough were evaluated. Univariable and multivariable regression models were generated to evaluate the association between impedance-pH and high-resolution manometry findings, endoscopic and clinical characteristics, and PPI response.

RESULTS

A total of 178 patients were included. Eighty-four of 178 cough patients (47.2%) displayed grade C-D erosive esophagitis or were characterized by a pathological acid exposure time (AET) and/or positive symptom association probability/symptom index. When also considering MNBI and PSPW, 135 of 178 patients (75.8%) were characterized by the evidence of reflux disease (P < 0.001). Eighty patients (44.9%) had cough responding to PPIs, whereas 98 (55.1%) were nonresponders (P = 0.071). At the receiver operating characteristic analysis, both PSPW index and MNBI were associated to PPI responsiveness. MNBI and PSPW index showed higher sensitivity in predicting PPI response compared with AET and symptom association probability/symptom index. The area under the curves of MNBI and PSPW index were significantly higher than that of AET (P < 0.01 for both comparisons). When patients were stratified according to AET and excluding those with erosive esophagitis, pathological MNBI or PSPW index, hiatal hernia, and hypomotility features were associated to PPI response in all groups.

DISCUSSION

Our results demonstrate the usefulness of an up-front esophageal testing in discriminating reflux-related cough patients and predicting PPI response.

Impaired Proximal Esophageal Contractility Predicts Pharyngeal Reflux in Patients With Laryngopharyngeal Reflux Symptoms

OBJECTIVES

The pathophysiology of laryngopharyngeal reflux (LPR) remains incompletely understood. Proximal esophageal motor dysfunction may impair bolus clearance, increasing the risk of pharyngeal refluxate exposure. We aimed to evaluate the association of proximal esophageal contractility with objective reflux metrics.

METHODS

We evaluated adults with LPR symptoms undergoing high-resolution manometry (HRM) and combined hypopharyngeal-esophageal multichannel intraluminal impedance-pH testing at a tertiary center between March 2018 and August 2019. Routine parameters per Chicago classification were obtained on HRM. Proximal esophageal contractility was evaluated using proximal contractile integral (PCI), which quantifies contractile pressure >20 mm Hg for the region spanning the distal margin of the upper esophageal sphincter and transition zone. Univariate (Kendall correlation and Student t test) and multivariable (general linear regression and logistic regression) analyses were performed.

RESULTS

We enrolled 138 patients (66.7% women, mean age 57.1 years) in this study. Lower PCI was associated with an elevated risk of increased pharyngeal reflux (adjusted odds ratio 0.83 per 100 mm Hg-s-cm change in PCI, 95% confidence interval: 0.69-0.98), with a trend toward increased bolus exposure time and total reflux events, after multivariable adjustment. The relationship between PCI and pharyngeal reflux was strongest among participants without a primary motility disorder on HRM (adjusted odds ratio 0.63, 95% confidence interval: 0.42-0.85, P interaction = 0.04). Among continuously expressed reflux parameters, lower PCI was significantly associated with more distal acid reflux events (β = -0.0094, P = 0.03) and total reflux events (β = -0.0172, P = 0.05), after adjusting for confounders.

DISCUSSION

Reduced proximal esophageal contractility as assessed by decreased PCI on HRM independently predicted increased pharyngeal reflux in patients with LPR symptoms, particularly among those without a coexisting motility disorder.

Anatomical and physiological characteristics in patients with Laryngopharyngeal Reflux Symptoms: A case-control study utilizing high-resolution impedance manometry

BACKGROUND/PURPOSE

This study aimed to explore the anatomical and physiological characteristics of patients with laryngopharyngeal reflux (LPR) symptoms, such as hoarseness, throat clearing, throat pain, globus, and chronic cough, with the novel high-resolution impedance manometry (HRIM).

METHODS

Consecutive patients exhibited at least one LPR symptom for ≥4 weeks after 2-month proton-pump inhibitor treatment were enrolled during November 2014 and March 2018 from single tertiary medical center. All patients completed validated symptom questionnaires, esophagogastroduodenoscopy, and HRIM. Healthy volunteers were also recruited for comparison of esophageal parameters on HRIM.

RESULTS

Eighty-nine LPR patients and 63 healthy volunteers were analyzed. Compared with healthy volunteers, LPR patients had significantly shorter upper and lower esophageal sphincters (UES and LES), a shorter intraabdominal esophagus (all P < 0.01), higher 4-s integrated relaxation pressures (IRP-4s) (P = 0.011) of the LES. After adjusted for age, sex, body weight, body height and alcohol consumption, multiple regression analysis showed that age, LES IRP-4s and the UES length were independent risk factors for LPR symptoms (OR 1.056, 95% CI 1.019-1.094; OR 1.107, 95% CI 1.004-1.222; OR 0.432, 95% CI 0.254-0.736, respectively). In subgroup analysis, patients with moderate LPR symptoms had lower IRP-4s (6.64 ± 4.55 vs. 8.69 ± 5.10, P = 0.049) and more failed peristalsis (27.33 ± 29.26 vs. 11.36 ± 21.20, P = 0.004) than those with mild LPR symptoms.

CONCLUSION

Our study suggests that esophageal structural factors and LES IRP-4s may contribute to the occurrence of LPR symptoms. Patients with moderate LPR symptoms were more likely to present with failed peristalsis.

Prevalence and clinical significance of esophageal motility disorders in patients with laryngopharyngeal reflux symptoms

BACKGROUND AND AIM

Esophageal motor dysfunction may underlie impaired bolus/refluxate clearance in laryngopharyngeal reflux (LPR). However, the prevalence of esophageal dysmotility and its correlation with reflux parameters and symptoms in LPR is not well established. The aim of this study was to evaluate the prevalence of coexisting esophageal dysmotility among patients with suspected LPR.

METHODS

This was a retrospective cohort study of 194 consecutive patients with LPR symptoms referred for high-resolution manometry (HRM) and combined hypopharyngeal-esophageal multichannel intraluminal impedance and pH testing at a tertiary center in March 2018 to August 2019. Validated symptom surveys were prospectively collected at time of testing, including Reflux Symptom Index, Gastroesophageal Reflux Disease Questionnaire, dominant symptom intensity, and 12-Item Short-Form Health Survey. HRM findings were categorized using Chicago Classification v3.0.

RESULTS

Abnormal findings on HRM were identified in 84 (43.3%) patients, with ineffective esophageal motility (n = 60, 30.9%) as the most common diagnosis. A disorder of esophagogastric junction outflow or a major disorder of peristalsis was identified in 26 (13.4%) patients, including 2 (1%) with achalasia and 7 (3.6%) with jackhammer esophagus. Reflux burden (distal, proximal, or pharyngeal) on combined hypopharyngeal-esophageal multichannel intraluminal impedance and pH testing did not differ across HRM findings. Patients reporting esophageal symptoms were more likely to have a primary motility disorder (odds ratio 2.34, P = 0.04). However, no significant differences in Reflux Symptom Index, Gastroesophageal Reflux Disease Questionnaire, or 12-Item Short-Form Health Survey were noted across HRM diagnoses.

CONCLUSION

Esophageal motility disorders are prevalent among patients with LPR symptoms, including up to one in seven with esophagogastric junction outflow or major peristaltic disorder. Patients with abnormal motility more likely report esophageal symptoms. Clinicians should be aware of these coexisting conditions, particularly in those with refractory symptoms.

The Cough Reflex: The Janus of Respiratory Medicine

In clinical practice, we commonly face adversity when encountering dysfunction of the cough reflex. Similar to ancient Roman deity Janus, it often presents with one of two opposing "faces". Continual aberrant activation of the cough reflex, also known as chronic cough, can cause great detriment to quality of life and many of these patients are left misdiagnosed and undertreated. In contrast, loss of normal functioning of the cough reflex is the cause of a significant proportion of mortality in the elderly, primarily through the development of aspiration pneumonia. In this review we discuss both hyper- and hypo-activation of the cough reflex and how airway reflux and chronic aspiration may be involved in the aetiology and sequalae of both disease states. We detail the physiological and pharmacological mechanisms involved in cough, and how the recent development of P2X3 receptor antagonists may lead to the first pharmaceutical agent licensed for chronic cough. The treatment and prevention of loss of the cough reflex, which has been largely neglected, is also discussed as novel low-cost interventions could help prevent a number of hospital and domiciliary deaths from both acute and chronic aspiration.

The Perils and Pitfalls of Esophageal Dysmotility in Idiopathic Pulmonary Fibrosis

INTRODUCTION

Gastroesophageal reflux plays a significant role in idiopathic pulmonary fibrosis (IPF). Given the morbidity and mortality associated with IPF, understanding the mechanisms responsible for reflux is essential if patients are to receive optimal treatment and management, especially given the lack of clear benefit of antireflux therapies. Our aim was to understand the inter-relationships between esophageal motility, lung mechanics and reflux (particularly proximal reflux-a prerequisite of aspiration), and pulmonary function in patients with IPF.

METHODS

We prospectively recruited 35 patients with IPF (aged 53-75 years; 27 men) who underwent high-resolution impedance manometry and 24-hour pH-impedance, together with pulmonary function assessment.

RESULTS

Twenty-two patients (63%) exhibited dysmotility, 16 (73%) exhibited ineffective esophageal motility (IEM), and 6 (27%) exhibited esophagogastric junction outflow obstruction. Patients with IEM had more severe pulmonary disease (% forced vital capacity: P = 0.032) and more proximal reflux (P = 0.074) than patients with normal motility. In patients with IEM, intrathoracic pressure inversely correlated with the number of proximal events (r = -0.429; P = 0.098). Surprisingly, inspiratory lower esophageal sphincter pressure (LESP) positively correlated with the percentage of reflux events reaching the proximal esophagus (r = 0.583; P = 0.018), whereas in patients with normal motility, it inversely correlated with the bolus exposure time (r = -0.478; P = 0.098) and number of proximal events (r = -0.542; P = 0.056). % forced vital capacity in patients with IEM inversely correlated with the percentage of reflux events reaching the proximal esophagus (r = -0.520; P = 0.039) and inspiratory LESP (r = -0.477; P = 0.062) and positively correlated with intrathoracic pressure (r = 0.633; P = 0.008).

DISCUSSION

We have shown that pulmonary function is worse in patients with IEM which is associated with more proximal reflux events, the latter correlating with lower intrathoracic pressures and higher LESPs.

Patients With Definite and Inconclusive Evidence of Reflux According to Lyon Consensus Display Similar Motility and Esophagogastric Junction Characteristics

Background/Aims

The role of esophageal high-resolution manometry (HRM) within Lyon consensus phenotypes, especially patients with inconclusive gastroesophageal reflux disease (GERD) evidence, has not been fully investigated. In this multicenter, observational study we aim to compare HRM parameters in patients with GERD stratified according to the Lyon consensus.

Methods

Clinical and endoscopic data, HRM and multichannel intraluminal impedance-pH (MII-pH) studies performed off proton pump inhibitor therapy in patients with esophageal GERD symptoms were reviewed. Lyon consensus criteria identified pathological GERD, reflux hypersensitivity, functional heartburn, and inconclusive GERD. Patients, with inconclusive GERD were further subdivided into 2 groups based on total reflux numbers (≤ 80 or > 80 reflux episodes) during the MII-pH recording time.

Results

A total of 264 patients formed the study cohort. Pathological GERD and inconclusive GERD patients were associated with higher numbers of reflux episodes, lower mean nocturnal baseline impedance (MNBI) values, and a higher proportion of patients with pathologic MNBI compared to functional heartburn (P < 0.05 for each comparison). On multivariate analysis, pathological GERD and inconclusive GERD patients, both with ≤ 80 or > 80 reflux episodes, were significantly associated with pathologic esophagogastric junction contractile integral values and with presence of hiatus hernia (type 2/3 esophagogastric junction). Patients with inconclusive GERD and > 80 reflux episodes were significantly associated with fragmented peristalsis and ineffective esophageal motility whilst inconclusive GERD with ≤ 80 reflux episodes were significantly associated with fragmented peristalsis.

Conclusion

Esophageal motor parameters on HRM are similar between pathologic and inconclusive GERD according to the Lyon consensus.

Understanding the relationship between esophageal motor disorders and reflux disease

INTRODUCTION

The management of gastro-esophageal reflux disease (GERD) patients is often complex as the clinical presentation is heterogeneous and the mechanisms underlying symptoms are multifactorial. In the past decades, investigations conducted with conventional manometry and, above all, the more accurate high resolution manometry (HRM), helped us in exploring the field of esophageal motility and in understanding the link between motor features and GERD pathogenesis.

AREAS COVERED

Several studies carried out with conventional manometry and HRM have confirmed a relevant role of esophageal motor function in GERD pathogenesis. In particular, HRM studies have shown a direct correlation between impaired esophageal body motility, disruption of the esophagogastric junction and reflux burden. These findings impact the clinical and therapeutical management of GERD patients. Moreover, HRM findings might be helpful in evaluating patients with proton pump inhibitor (PPI) resistance and inconclusive evidences of GERD.

EXPERT OPINION

The relationship between esophageal motility and GERD pathogenesis needs to be further evaluated by multicenter outcome studies involving a large number of GERD patients and healthy controls. However, other more promising areas could be progressed.

High-resolution Manometry Determinants of Refractoriness of Reflux Symptoms to Proton Pump Inhibitor Therapy

Background/Aims

Impaired esophageal motility and disrupted esophagogastric junction (EGJ) on high-resolution manometry (HRM) have been associated with increased reflux severity in gastroesophageal reflux disease (GERD) patients. However, there are limited data evaluating HRM parameters in proton pump inhibitors (PPI) non-responders.

Methods

Clinical and endoscopic data, HRM and multichannel intraluminal impedance-pH studies performed of PPI therapy in patients with typical GERD symptoms were reviewed from 3 international centers. Frequency of GERD symptoms was assessed on and off PPI therapy in both non-responders (< 50% symptom improvement on PPI therapy) and responders. Rome IV definitions identified non-erosive reflux disease, reflux hypersensitivity, and functional heartburn. Univariate and multivariate analyses were performed to determine predictors of non-response.

Results

Of 204 patients, 105 were PPI non-responders and 99 were responders. Non-responders showed higher EGJ contractile integral values, and a lower frequency of type II and III EGJ morphology (P ≤ 0.03 for each comparison). Esophageal body diagnoses on HRM (fragmented peristalsis, ineffective esophageal motility, or absent peristalsis) did not predict non-response. On multivariate analysis, non-pathological acid exposure time (OR, 2.5; 95% CI, 1.2-5.0; P < 0.001), normal mean nocturnal baseline impedance values (OR, 2.7-2.4; 95% CI, 1.0-6.1; P < 0.05), normal EGJ contractile integral values (OR, 3; 95% CI, 1.3-7.4; P = 0.012), and presence of type I EGJ morphology (OR, 1.9; 95% CI, 1.0-3.4; P = 0.044) were associated with an unfavorable response to PPIs.

Conclusions

Intact EGJ metrics on HRM complement normal reflux burden in predicting non-response to PPI therapy. HRM has value in the evaluation of PPI non-responders.

Impact of ineffective esophageal motility on chemical clearance in patients with gastroesophageal reflux symptoms

Ineffective esophageal motility (IEM) is the most common manometric abnormality in gastroesophageal reflux disease (GERD). However, the impact of IEM on esophageal chemical clearance has not been fully investigated. This study aimed to determine the impact of IEM on esophageal chemical clearance in patients with GERD. A total of 369 patients with GERD symptoms who underwent upper endoscopy and high-resolution manometry (HRM) test were retrospectively analyzed. The relationship between IEM and erosive esophagitis was examined. In addition, the impact of IEM on chemical clearance was examined in patients who underwent an additional combined multichannel intraluminal impedance-pH (MII-pH) test. Esophageal chemical clearance capability was evaluated via postreflux swallow-induced peristaltic wave (PSPW) index and acid clearance time (ACT). Of 369 patients, 181 (49.1%) had esophageal motility disorders, of which 78 (21.1%) had IEM. The proportion of IEM patients in those with erosive esophagitis and those without were 16.2% and 21.7%, respectively, and no significant difference was observed (P = 0.53). After excluding patients other than those with IEM and normal esophageal motility, 64 subsequently underwent MII-pH test. The median values of the PSPW index in the IEM and normal esophageal motility group were 11.1% (4.2%-20.0%) and 17.1% (9.8%-30.6%), respectively. The PSPW index was significantly lower in the IEM group than in the normal esophageal motility group (P < 0.05). The median ACT values in the IEM group and normal esophageal motility group were 125.5 (54.0-183.5) seconds and 60.0 (27.2-105.7) seconds, respectively. The ACT was significantly longer in the IEM group than in the normal esophageal motility group (P < 0.05). In conclusion, IEM was found to be associated with chemical clearance dysfunction as measured against the PSPW index and ACT. As this condition could be a risk factor for GERD, future treatments should be developed with a focus on chemical clearance.

Fragmented and failed swallows on esophageal high-resolution manometry associate with abnormal reflux burden better than weak swallows

BACKGROUND

Association between proportions of hypomotile swallows on esophageal high-resolution manometry (HRM) and esophageal reflux burden remains incompletely understood. We investigated relationships between hypomotility, acid exposure time (AET), and mean nocturnal baseline impedance (MNBI) on ambulatory reflux monitoring.

METHODS

Clinical data, HRM, and ambulatory pH-impedance studies (performed off acid suppression) from patients with persisting reflux symptoms were reviewed from five international centers. AET (abnormal > 6%) and MNBI (abnormal < 2292 ohms) were extracted from pH-impedance studies. Distal contractile integral (DCI) designated esophageal peristalsis into normal (DCI > 450 mmHg.cm.s), fragmented (DCI > 450 mmHg.cm.s with breaks > 5 cm), weak (DCI 100-450 mmHg.cm.s), and failed (DCI < 100 mm mmHg.cm.s) sequences. Univariate and multivariate analyses were performed to identify motor associations of abnormal reflux burden.

KEY RESULTS

Of 351 patients (52.1 ± 0.8 years, 67%F), 29.3% had AET > 6% and 61.8% had MNBI < 2292 ohms. On univariate analysis, both fragmented peristalsis and IEM associated with abnormal AET (P ≤ .01) and MNBI (P ≤ .03); reflux burden was more profound with >70% fragmented as well as ineffective sequences compared to ≤70% for each (P < .05 for each comparison). When weak and failed sequences within IEM were separately analyzed, ≥50% failed sequences predicted abnormal AET (P ≤ .009), and ≥50% weak sequences did not (P = .14). On multivariate regression, ≥50% failed sequences predicted abnormal AET (P = .02), and >70% ineffective sequences trended strongly (P = .069); >70% ineffective sequences predicted abnormal MNBI (P = .046), and >70% fragmented sequences trended strongly (P = .076).

CONCLUSIONS AND INFERENCES

Breaks in esophageal peristaltic integrity seen with fragmented and failed sequences are more relevant to abnormal esophageal acid burden than weak sequences.

Gastroesophageal reflux disease and chronic cough: A possible mechanism elucidated by ambulatory pH-impedance-pressure monitoring

BACKGROUND

The pathophysiological mechanism(s) of gastroesophageal reflux disease (GERD)-related chronic cough (CC) is unclear. We aimed to determine the mechanism of reflux-induced cough by synchronous monitoring of reflux episodes, esophageal motility, and cough.

METHODS

Patients with GERD were prospectively enrolled and classified into GERD with CC (GERD-CC) and without CC (GERD) groups. Twenty-four-hour ambulatory pH-impedance-pressure monitoring was performed; the reflux patterns, esophageal motility during prolonged exposure to acid and characteristics of reflux episodes that induced coughing paroxysms were analyzed.

KEY RESULTS

Thirty-one patients with GERD-CC and 47 with GERD were enrolled; all of whose monitoring results fulfilled the criteria for diagnosis of GERD. Patients with GERD-CC had higher reflux symptom scores, longer exposure to acid, higher DeMeester scores, and more frequent reflux episodes, proximal extent reflux detected by impedance, and higher percentage of strongly acidic reflux than patients in the GERD group (all P < .05). Of 63 reflux-cough episodes identified in the GERD-CC group, 74.6% of distal reflux and 67.0% of proximal reflux episodes were acidic. More patients had low pan-esophageal pressure in primary peristalsis (48.5% vs 11.8%, P = .000) and synchronous contraction in secondary peristalsis during prolonged exposure to acid in the GERD-CC than in the GERD group (63.9% vs 9.1%, P = .000).

CONCLUSIONS & INFERENCES

Proximal acidic reflux and distal reflux-reflex are jointly associated with reflux-induced cough in patients with GERD. Low pan-esophageal pressure in primary peristalsis and synchronous contraction in secondary peristalsis may play important roles in GERD-associated chronic cough.

Ineffective esophageal motility: Concepts, future directions, and conclusions from the Stanford 2018 symposium

BACKGROUND

Ineffective esophageal motility (IEM) is a heterogenous minor motility disorder diagnosed when ≥50% ineffective peristaltic sequences (distal contractile integral <450 mm Hg cm s) coexist with normal lower esophageal sphincter relaxation (integrated relaxation pressure < upper limit of normal) on esophageal high-resolution manometry (HRM). Ineffective esophageal motility is not consistently related to disease states or symptoms and may be seen in asymptomatic healthy individuals.

PURPOSE

A 1-day symposium of esophageal experts reviewed existing literature on IEM, and this review represents the conclusions from the symposium. Severe IEM (>70% ineffective sequences) is associated with higher esophageal reflux burden, particularly while supine, but milder variants do not progress over time or consistently impact quality of life. Ineffective esophageal motility can be further characterized using provocative maneuvers during HRM, especially multiple rapid swallows, where augmentation of smooth muscle contraction defines contraction reserve. The presence of contraction reserve may predict better prognosis, lesser reflux burden and confidence in a standard fundoplication for surgical management of reflux. Other provocative maneuvers (solid swallows, standardized test meal, rapid drink challenge) are useful to characterize bolus transit in IEM. No effective pharmacotherapy exists, and current managements target symptoms and concurrent reflux. Novel testing modalities (baseline and mucosal impedance, functional lumen imaging probe) show promise in elucidating pathophysiology and stratifying IEM phenotypes. Specific prokinetic agents targeting esophageal smooth muscle need to be developed for precision management.

Evaluation of Esophageal Contraction Reserve Using HRM in Symptomatic Esophageal Disease

Esophageal high resolution manometry (HRM) is the gold standard for assessment of esophageal motor disorders, but motor responses to the standard 5 mL water swallow protocol may not provide precision in defining minor motor disorders. Provocative maneuvers, particularly multiple rapid swallows (MRS), have been used to assess deglutitive inhibition during the repetitive swallows, and the contractile response following the final swallow of the sequence. The augmentation of esophageal smooth muscle contraction following MRS is termed contraction reserve. This is determined as the ratio between esophageal body contraction vigor (distal contractile integral, DCI) following MRS to the mean DCI after single swallows, which is ≥1 in the presence of contraction reserve. Reliable assessment of contraction reserve requires the performance of 3 MRS maneuvers during HRM. Absence of contraction reserve is associated with a higher likelihood of late postfundoplication dysphagia and may correlate with higher esophageal reflux burden on ambulatory reflux monitoring. Esophageal motor responses to abdominal compression, functional lumen imaging probe (FLIP) balloon distension, and pharmacologic testing (using edrophonium and cisapride) may correlate with contraction reserve. Other provocative tests useful during HRM include rapid drink challenge, solid and viscous swallows, and standardized test meals, which are more useful in evaluation of esophageal outflow obstruction and dysphagia syndromes than in identification of contraction reserve. Provocative maneuvers have been recommended as part of routine HRM protocols, and while useful clinical information can be gleaned from these maneuvers, further research is necessary to determine the precise role of provocative testing in clinical esophagology.

Unilateral Versus Bilateral Lung Transplantation: Do Different Esophageal Risk Factors Predict Chronic Allograft Failure?

GOALS

To assess the effect of unilateral versus bilateral lung transplantation (LTx) on esophageal motility and gastroesophageal reflux, and the association with the development of obstructive chronic lung allograft dysfunction (o-CLAD).

BACKGROUND

We have shown that esophagogastric junction outflow obstruction, incomplete bolus transit, and proximal reflux are all independent risk factors for the development of chronic allograft failure. However, it remains unclear whether these factors are influenced by the type of surgery and how this relates to allograft failure.

STUDY

Patients post-LTx (n=48, 24 female; aged 20 to 73 y) completed high-resolution impedance manometry and 24-hour pH/impedance.

RESULTS

Patients who had undergone unilateral LTx were more likely to exhibit esophagogastric junction outflow obstruction (47% vs. 18%; P=0.046) and less likely to exhibit hypocontractility (0% vs. 21%; P=0.058) than those who had undergone bilateral LTx. Although the proportion of patients exhibiting gastroesophageal reflux was no different between groups (33% vs. 39%; P=0.505), those undergoing bilateral LTx were more likely to exhibit proximal reflux (8% vs. 37%; P=0.067). Univariate Cox proportion hazards regression analysis did not show a difference between unilateral versus bilateral LTx in the development of o-CLAD (hazard ratio=1.17; 95% confidence interval, 0.48-2.85; P=0.723).

CONCLUSION

The type of LTx performed seems to lead to different risk factors for the development of o-CLAD. Physicians should be aware of these differences, as they may need to be taken into account when managing patient's post-LTx.

High-resolution Manometry Findings During Solid Swallows Correlate With Delayed Reflux Clearance and Acid Exposure Time in Non-erosive Reflux Disease Patients

Background/Aims

The role of esophageal motility in determining gastroesophageal reflux disease (GERD) severity has not been completely evaluated. A few studies have investigated high-resolution manometry (HRM) patterns during solid swallows. The present study evaluates the HRM patterns of non-erosive reflux disease (NERD) patients during both liquid and solid swallows and their correlation with the severity of GERD.

Methods

In 23 NERD patients and 15 healthy volunteers (HVs) HRM was performed during a standard solid meal in a seated position, followed by 24-hour impedance-pH monitoring.

Results

Of the 31 patients, 10 showed a pathological acid exposure time (AET; NERD patients), 13 a normal pH profile with positive symptom association probability (SAP; reflux hypersensitivity patients), and 8 normal AET and SAP (functional heartburn patients). Mean distal contractile integral and distal latency values, in all patient groups and HVs, were significantly higher during solid swallows. In the group of 10 NERD patients, the number of large breaks of the esophageal peristalsis was 16 out of 100 liquid swallows (16%) and 31 out of 171 solid swallows (18%). Fourteen out of 100 liquid swallows (14%) and 25 out of 171 solid swallows (15%) resulted ineffective. Mean reflux clearing time at multichannel intraluminal impedance-pH was 17.6 ± 3.7 seconds. NERD patients presented, during solid swallows, a significantly higher proportion of large peristaltic breaks and of ineffective swallows than reflux hypersensitivity and functional heartburn patients.

Conclusion

HRM during solid swallows reveals motor abnormalities, undetected during liquid swallows, which might be involved in delaying reflux and acid clearance in patients with GERD.

Roles of High-resolution Manometry in Predicting Incomplete Bolus Transit in Patients With Dysphagia

BACKGROUND

High-resolution manometry (HRM) is used to assess esophageal motility diseases. Abnormalities in a number of HRM parameters have been reported in patients with dysphagia. However, it is unclear whether some of abnormal HRM parameters are predictive of dysphagia. The aim of this retrospective study was to investigate the roles of HRM parameters in predicting incomplete bolus clearance (IBC) in patients with dysphagia using high-resolution impedance manometry.

METHODS

A total of 644 wet swallows were reviewed and analyzed in 63 patients with symptoms of dysphagia or reflux who underwent a clinical high-resolution impedance manometry test. IBC was defined based on impedance measurement. The relationship of each of abnormal HRM parameters with IBC was analyzed and their roles in predicting IBC were determined.

RESULTS

Patients with symptoms of both dysphagia and reflux showed the highest IBC rate, and patients with symptoms of reflux had the lowest IBC rate. The IBC was more prevalent in the distal esophagus. Premature contractions and peristalsis with large breaks were associated with a higher IBC rate in the proximal esophagus (P<0.05); large breaks, ineffective peristalsis, and abnormalities of the esophageal gastric junction functions were associate with higher IBC rates in the distal esophagus (P<0.05). Abnormalities in a number of motility parameters were able to predict IBC with high specificities and/or high sensitivity, such as pan esophageal pressurization, ineffective peristalsis, and large breaks. Abnormal integrative relaxation pressure of the lower esophageal sphincter with concurrent pan esophageal pressurization, ineffective peristalsis, or large breaks is predictive of IBC with nearly 100% of specificity.

CONCLUSIONS

Abnormalities in a number of HRM parameters are not only useful in diagnosing esophageal motility diseases, but also valuable in predicting IBC during swallowing.

Chronic Cough Is Associated With Long Breaks in Esophageal Peristaltic Integrity on High-resolution Manometry

Background/Aims

Breaks in the peristaltic contour on esophageal high-resolution manometry (HRM) may be associated with bolus retention in the esophagus. We evaluated the relationship between peristaltic breaks and esophageal symptoms, reflux exposure, and symptom outcomes in a prospective patient cohort.

Methods

Two hundred and eighteen patients (53.2 ± 0.9 years, 68.3% female) undergoing both pH-impedance testing and HRM over a 5–year period were prospectively evaluated. Demographics, symptom presentation, acid exposure time, symptom association probability, and symptom burden scores were collected. Outcomes were assessed on follow-up using changes in symptom scores. Presence of long breaks (≥ 5 cm) on HRM was assessed by a blinded author. Relationships between breaks, reflux parameters, presenting symptoms, and outcomes were assessed.

Results

Patients with long breaks were more likely to have cough as a presenting symptom than those without (43.4% vs 28.6%, P = 0.024); statistical differences were not demonstrated with other symptoms (P ≥ 0.3). Numbers of swallows with long breaks were higher in patients with cough compared to those without (2.4 ± 0.3 vs 1.6 ± 0.2, P = 0.021); differences were not found with other symptoms (P ≥ 0.4). Long breaks were not associated with age, gender, race, reflux burden, symptom association, or changes in symptom metrics (P ≥ 0.1 for all comparisons). Among patients with cough, the presence of long breaks predicted suboptimal symptom improvement with antireflux therapy (P = 0.018); this difference did not hold true for other symptoms (P ≥ 0.2).

Conclusions

Long breaks in esophageal peristaltic integrity are associated with cough. The presence of long breaks is associated with suboptimal benefit from antireflux therapy.

Aspiration Pneumonia and Related Syndromes

Aspiration is a syndrome with variable respiratory manifestations that span acute, life-threatening illnesses, such as acute respiratory distress syndrome, to chronic, sometimes insidious, respiratory disorders such as aspiration bronchiolitis. Diagnostic testing is limited by the insensitivity of histologic testing, and although gastric biomarkers for aspiration are increasingly available, none have been clinically validated. The leading mechanism for microaspiration is thought to be gastroesophageal reflux disease, largely driven by the increased prevalence of gastroesophageal reflux across a variety of respiratory disorders, including chronic obstructive pulmonary disease, asthma, idiopathic pulmonary fibrosis, and chronic cough. Failure of therapies targeting gastric acidity in clinical trials, in addition to increasing concerns about both the overuse of and adverse events associated with proton pump inhibitors, raise questions about the precise mechanism and causal link between gastroesophageal reflux and respiratory disease. Our review summarizes key aspiration syndromes with a focus on reflux-mediated aspiration and highlights the need for additional mechanistic studies to find more effective therapies for aspiration syndromes.

Esophageal dysmotility according to Chicago classification v3.0 vs v2.0: Implications for association with reflux, bolus clearance, and allograft failure post-lung transplantation

BACKGROUND

Proximal reflux and incomplete transit of boluses swallowed are risk factors for obstructive chronic lung allograft dysfunction (o-CLAD) post-lung transplantation (LTx). Likewise, so is esophagogastric junction outflow obstruction (EGJOO), but not hypo-contractility, when diagnosed using Chicago Classification (CC) v3.0. Given, peristaltic breaks as defined using CCv2.0 can prolong esophageal clearance, both swallowed and refluxed, but which are deemed within normality using CCv3.0, our aim was to determine whether hypo-contractility as diagnosed using CCv2.0, influences the association with reflux, along with its clearance, and that of boluses swallowed, and thus its association to allograft failure.

METHODS

Esophageal motility abnormalities were classified using CC v3.0 and v2.0 in 50 patients post-LTx (26 female, 55 years (20-73 years)).

RESULTS

Reclassification from CCv3.0 to v2.0 resulted in 7 patients with normal motility being reclassified to hypo-contractility (n = 6) or hyper-contractility (n = 1); 2 patients with hypo-contractility to normal motility; and 3 patients with EGJOO without hyper-contractility to EGJOO with hyper-contractility. The main consequence of reclassification was that the sub-group exhibiting hypo-contractility became more likely to have abnormal numbers of reflux events (P = .025) and incomplete bolus transit (P = .002) than those with normal motility using CCv2.0; associations not seen using CCv3.0. Irrespective of CC used only patients with EGJOO appeared more likely to develop o-CLAD than those with normal motility (P < .05).

CONCLUSIONS

Irrespective of CC used, o-CLAD appears linked to EGJOO. CCv2.0 however, accentuates the increased reflux and incomplete bolus transit associated with hypo-contractility post-LTx, suggesting that these motor abnormalities, though considered minor, may be of importance after lung transplant.

Assessment of Esophageal High-Resolution Impedance Manometry in Patients with Nonobstructive Dysphagia

Background

High-resolution impedance manometry (HRIM) can calculate the bolus motion parameters and the ratio of complete esophageal transit besides the conventional esophageal dynamic parameters; therefore, we could better manage the patients with nonobstructive dysphagia (NOD) clinically.

Aim

To analyze the HRIM parameter results of NOD patients and evaluate the characteristics of their esophageal motility and transit function.

Methods

In total, 58 NOD patients were assessed and the clinical diagnoses were determined. HRIM was performed, and both conventional high-resolution manometry and esophageal transit parameters were analyzed.

Results

In 58 NOD patients, 28 patients had achalasia, 3 esophagogastric junction outflow obstruction, and 20 nonspecific esophageal motility disorders, and 7 were normal. Impedance results demonstrated that all the patients with achalasia exhibited incomplete esophageal transit (ICET), three patients with esophagogastric junction outflow obstruction showed ICET, and the average bolus transit time (BTT) was 6.6 ± 1.2 sec. In 20 nonspecific esophageal motility disorders, 13 patients with gastroenterologly reflux disease (GERD) presented ineffective esophageal motility and fragmented peristalsis, and 65.0% swallows had exhibited ICET. However, 49.1% swallows of 7 nonspecific esophageal motility disorder patients with non-GERD had exhibited ICET. The average BTT in 13 GERD patients was longer than that in the non-GERD patients (8.1 ± 1.1 sec versus 5.5 ± 0.3 sec, P < 0.05). And in the seven patients with normal esophagus function, 3.5% swallows showed ICET and BTT was 5.6 ± 0.3 sec.

Conclusion

Achalasia was the most common esophageal dysmotility in NOD patients, followed by nonspecific esophageal motility disorders. The clinical diagnoses of NOD were mostly achalasia and GERD. Impedance assessments showed that all achalasia cases exhibited ICET, and other esophageal motility abnormalities that represented ICET were associated with contraction break and ineffective swallow. Compared to non-GERD patients, BTT was significantly prolonged in patients with GERD.

The role of high resolution oesophageal manometry in occult respiratory symptoms

PURPOSE

Cough Hypersensitivity Syndrome is the urge to cough following minimal stimulation, but its mechanism and method of provocation remain unexplained. 121 patients (44 males, 77 females; age range 18-81 years) were evaluated.

PROCEDURES

High resolution manometry was performed on consecutive patients presenting with unexplained respiratory symptoms (Respiratory Group 61). Data were compared with matched controls, i.e. dyspepsia without respiratory symptoms (Dyspepsia Group 60).

MAIN FINDINGS

Results showed increased inspiratory gastro-oesophageal pressure gradient due to significantly lower intra-oesophageal pressure on inspiration (p = 0.001), and reduced oesophageal motility in the Respiratory Group.

CONCLUSIONS

Further research in respiratory conditions characterised by decreased intrathoracic pressure during inspiration is needed.

Classification of esophageal motor findings in gastro-esophageal reflux disease: Conclusions from an international consensus group

BACKGROUND

High-resolution manometry (HRM) has resulted in new revelations regarding the pathophysiology of gastro-esophageal reflux disease (GERD). The impact of new HRM motor paradigms on reflux burden needs further definition, leading to a modern approach to motor testing in GERD.

METHODS

Focused literature searches were conducted, evaluating pathophysiology of GERD with emphasis on HRM. The results were discussed with an international group of experts to develop a consensus on the role of HRM in GERD. A proposed classification system for esophageal motor abnormalities associated with GERD was generated.

KEY RESULTS

Physiologic gastro-esophageal reflux is inherent in all humans, resulting from transient lower esophageal sphincter (LES) relaxations that allow venting of gastric air in the form of a belch. In pathological gastro-esophageal reflux, transient LES relaxations are accompanied by reflux of gastric contents. Structural disruption of the esophagogastric junction (EGJ) barrier, and incomplete clearance of the refluxate can contribute to abnormally high esophageal reflux burden that defines GERD. Esophageal HRM localizes the LES for pH and pH-impedance probe placement, and assesses esophageal body peristaltic performance prior to invasive antireflux therapies and antireflux surgery. Furthermore, HRM can assess EGJ and esophageal body mechanisms contributing to reflux, and exclude conditions that mimic GERD.

CONCLUSIONS & INFERENCES

Structural and motor EGJ and esophageal processes contribute to the pathophysiology of GERD. A classification scheme is proposed incorporating EGJ and esophageal motor findings, and contraction reserve on provocative tests during HRM.

Impaired Esophageal Motility and Clearance Post-Lung Transplant: Risk For Chronic Allograft Failure

OBJECTIVES

Gastroesophageal reflux is common in patients post-lung transplantation (LTx) and thus considered a risk factor for aspiration and consequently allograft rejection and the development of chronic allograft failure. However, evidence supporting this remains unclear and often contradictory. Our aim was to examine the role played by esophageal motility on gastroesophageal reflux exposure, along with its clearance and that of boluses swallowed, and the relationship to development of obstructive chronic lung allograft dysfunction (o-CLAD).

METHODS

Patients post-LTx (n=50, 26 female; mean age 55 years (range, 20-73 years)) completed high-resolution impedance manometry and 24-h pH/impedance. Esophageal motility abnormalities were classified based upon the Chicago Classification version 3.0.

RESULTS

Esophagogastric junction outflow obstruction alone (EGJOOa) (P=0.01), incomplete bolus transit (IBT) (P=0.006) and proximal reflux (P=0.042) increased the risk for o-CLAD. Patients with EGJOOa were most likely to present with o-CLAD (77%); despite being less likely to exhibit abnormal numbers of reflux events (10%) compared with those with normal motility (o-CLAD: 29%, P<0.05; abnormal reflux events: 64%, P<0.05). Patients with EGJOOa had lower total reflux bolus exposure time than those with normal motility (0.6 vs. 1.5%; P<0.05). In addition, poor esophageal clearance documented by abnormal post-reflux swallow-induced peristaltic wave index associated with o-CLAD; inversely correlating with the proportion of reflux events reaching the proximal esophagus (r=-0.251; P=0.052).

CONCLUSIONS

These observations support esophageal dysmotility, especially EGJOOa, and impaired clearance of swallowed bolus or refluxed contents, more so than just the presence of gastroesophageal reflux alone, as important risk factors in the development of o-CLAD.

Oropharyngeal acid reflux and motility abnormalities of the proximal esophagus

AIM

To investigate the relationship between pathological oropharyngeal (OP) acid exposure and esophageal motility in patients with extra-esophageal syndromes.

METHODS

In this prospective study we enrolled consecutive outpatients with extra-esophageal symptoms suspected to be related to gastroesophageal reflux disease (GERD). We enrolled only patients with a reflux symptom index (RSI) score-higher than 13 and with previous lung, allergy and ear, nose and throat evaluations excluding other specific diagnoses. All patients underwent 24-h OP pH-metry with the Dx probe and esophageal high-resolution manometry (HRM). Patients were divided into two groups on the basis of a normal or pathological pH-metric finding (Ryan Score) and all manometric characteristics of the two groups were compared.

RESULTS

We examined 135 patients with chronic extra-esophageal syndromes. Fifty-one were considered eligible for the study. Of these, 42 decided to participate in the protocol. Patients were divided into two groups on the basis of normal or pathological OP acid exposure. All the HRM parameters were compared for the two groups. Significant differences were found in the median upper esophageal sphincter resting pressure (median 71 mmHg vs 126 mmHg, P = 0.004) and the median proximal contractile integral (median 215.5 cm•mmHg•s vs 313.5 cm•mmHg•s, P = 0.039), both being lower in the group with pathological OP acid exposure, and the number of contractions with small or large breaks, which were more frequent in the same group. This group also had a larger number of peristaltic contractions with breaks in the 20 mmHg isobaric contour (38.7% vs 15.38%, P < 0.0001).

CONCLUSION

In patients with suspected GERD-related extra-esophageal syndromes pathological OP acid exposure was associated with weaker proximal esophageal motility.

Respiratory disease and the oesophagus: reflux, reflexes and microaspiration

Gastro-oesophageal reflux is associated with a wide range of respiratory disorders, including asthma, isolated chronic cough, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and cystic fibrosis. Reflux can be substantial and reach the proximal margins of the oesophagus in some individuals with specific pulmonary diseases, suggesting that this association is more than a coincidence. Proximal oesophageal reflux in particular has led to concern that microaspiration might have an important, possibly even causal, role in respiratory disease. Interestingly, reflux is not always accompanied by typical reflux symptoms, such as heartburn and/or regurgitation, leading many clinicians to empirically treat for possible gastro-oesophageal reflux. Indeed, costs associated with use of acid suppressants in pulmonary disease far outweigh those in typical GERD, despite little evidence of therapeutic benefit in clinical trials. This Review comprehensively examines the possible mechanisms that might link pulmonary disease and oesophageal reflux, highlighting the gaps in current knowledge and limitations of previous research, and helping to shed light on the frequent failure of antireflux treatments in pulmonary disease.

Cough reflex sensitization from esophagus and nose

The diseases of the esophagus and nose are among the major factors contributing to chronic cough although their role in different patient populations is debated. Studies in animal models and in humans show that afferent C-fiber activators applied on esophageal or nasal mucosa do not initiate cough, but enhance cough induced by inhaled irritants. These results are consistent with the hypothesis that activation of esophageal and nasal C-fibers contribute to cough reflex hypersensitivity observed in chronic cough patients with gastroesophageal reflux disease (GERD) and chronic rhinitis, respectively. The afferent nerves mediating cough sensitization from the esophagus are probably the neural crest-derived vagal jugular C-fibers. In addition to their responsiveness to high concentration of acid typical for gastroesophageal reflux (pH < 5), esophageal C-fibers also express receptors for activation by weakly acidic reflux such as receptors highly sensitive to acid and receptors for bile acids. The nature of sensory pathways from the nose and their activators relevant for cough sensitization are less understood. Increased cough reflex sensitivity was also reported in many patients with GERD or rhinitis who do not complain of cough indicating that additional endogenous or exogenous factors may be required to develop chronic coughing in these diseases.

Effects of acotiamide on esophageal motor function and gastroesophageal reflux in healthy volunteers

Background

The prevalence of gastroesophageal reflux disease (GERD) has been increasing worldwide, with proton pump inhibitor (PPI) administration the current mainstay therapy for affected individuals. However, PPI efficacy is insufficient especially for non-erosive reflux disease. Although it has been reported that prokinetic drugs improve GERD, their effects on esophageal function remain to be clearly investigated. In the present study, we evaluated the direct effects of acotiamide, a novel prokinetic agent for the treatment of functional dyspepsia, on esophageal motor function and gastroesophageal reflux.

Methods

Ten adult healthy volunteers (average age 24 years, range 20–36 years; 7 males, 3 females) were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure with and without acotiamide administration were recorded using high resolution manometry using a cross-over protocol. Total and acidic reflux levels for 24 h and during the postprandial period were also recorded using a multichannel intraluminal impedance and pH monitoring system. Data were analyzed blind by one observer.

Results

Acotiamide at a standard dose of 300 mg/day did not significantly stimulate esophageal motor function. Although the frequency of swallows with weak contraction tended to decrease with acotiamide administration, the difference as compared to no administration was not statistically significant. In addition, the drug neither decreased total or postprandial gastroesophageal acid/non-acid reflux events nor accelerated esophageal clearance time.

Conclusions

Acotiamide, a novel gastrointestinal motility modulator, at a standard dose did not significantly affect esophageal motor functions or gastroesophageal reflux in healthy adults. Additional investigations with GERD patients are necessary to elucidate its clinical significance.

Trial registration

This study was registered on 1st August 2013 with the University Hospital Medical Information Network (UMIN) clinical trials registry, as number: UMIN000011260.