Dabigatran-induced esophagitis: The prevalence and endoscopic characteristics

Drug-induced mucosal alterations observed during esophagogastroduodenoscopy

Several features of drug-induced mucosal alterations have been observed in the upper gastrointestinal tract, i.e., the esophagus, stomach, and duodenum. These include pill-induced esophagitis, desquamative esophagitis, worsening of gastroesophageal reflux, chemotherapy-induced esophagitis, proton pump inhibitor-induced gastric mucosal changes, medication-induced gastric erosions and ulcers, pseudomelanosis of the stomach, olmesartan-related gastric mucosal inflammation, lanthanum deposition in the stomach, zinc acetate hydrate tablet-induced gastric ulcer, immune-related adverse event gastritis, olmesartan-asso-ciated sprue-like enteropathy, pseudomelanosis of the duodenum, and lanthanum deposition in the duodenum. For endoscopists, acquiring accurate knowledge regarding these diverse drug-induced mucosal alterations is crucial not only for the correct diagnosis of these lesions but also for differential diag-nosis of other conditions. This minireview aims to provide essential information on drug-induced mucosal alterations observed on esophagogastroduodenoscopy, along with representative endoscopic images.

Dabigatran-induced esophagitis with full circumferential blue pigmentation

Dabigatran is a useful and widely used drug for stroke prevention in patients with atrial fibrillation. However, it has been reported to cause esophagitis. Herein, we report the case of a 77-year-old man with dabigatran-induced esophagitis with blue pigmentation, which is known to be a rare adverse effect. The patient presented to our hospital with a tightness of the chest and anorexia. Computed tomography revealed a thickening of the entire esophageal wall, with an upper esophageal predominance. Esophagogastroduodenoscopy was performed, which showed that the cervical and upper thoracic esophagus had blue pigmentation with edematous changes, partial narrowing, and longitudinal sloping. We replaced dabigatran with edoxaban, a similar anticoagulation medication. The patient was closely monitored for 1 month after switching to edoxaban. The follow-up esophagogastroduodenoscopy showed marked improvements, revealing resolution of the bluish discoloration and edematous changes, and the patient's complaints regarding the tightness of the chest and anorexia were also resolved. It is important to recognize that such side effects can occur with dabigatran, a drug that is frequently used in daily practice. Considering the fact that strong edematous changes can cause indigo carmine pigmentation associated with dabigatran stagnation, we recommend switching to another anticoagulant if esophagitis occurs during dabigatran administration.

Nonvitamin K oral anticoagulants with proton pump inhibitor cotherapy ameliorated the risk of upper gastrointestinal bleeding

Proton pump inhibitors (PPIs) can reduce the risk of upper gastrointestinal bleeding (UGIB) in patients who are taking oral anticoagulants. This study aimed to identify the association between NOACs with PPI cotherapy and UGIB. This retrospective cohort analysis included patients over the age of 18 years who were using NOACs between 2013 and 2020. NOAC categories, concomitant medications, endoscopic findings, the HAS-BLED score and the Charlson Comorbidity Index score were recorded. Using Poisson regression models, the relationship between UGIB events and risk factors was analyzed. Throughout a mean follow-up of 29.5 months, 14 (5.1%) individuals experienced UGIB. The incidence of UGIB was greater in patients receiving NOACs without PPIs (2.7 [1.26-5.60] per 1000) than in those receiving NOACs with PPIs (1.3 [0.61-2.67] per 1000). Patients receiving NOACs with PPIs had a 79.2% lower incidence of UGIB than patients receiving NOAC monotherapy (RR 0.208, 95% CI 0.061-0.706; p = 0.012). Female sex and the HAS-BLED score were associated with UGIB (RR 5.043; 95% CI 1.096-23.20; p = 0.038; RR 2.024; 95% CI 1.095-3.743; p = 0.024, respectively). Patients receiving NOAC and PPI cotherapy had a lower incidence of UGIB than those receiving NOACs alone, and female sex was a risk factor for UGIB in NOAC-treated patients.

Comparison of the efficacy and safety between rivaroxaban and dabigatran in the treatment of acute portal vein thrombosis in cirrhosis

BACKGROUND

New oral anticoagulants (NOACs) have been becoming prevalent in recent years and are increasingly used in the treatment of port vein thrombosis. The difference of the efficacy and safety between rivaroxaban and dabigatran remains unclear in the treatment of cirrhotic patients with acute portal vein thrombosis (PVT).

METHODS

This retrospective study included all consecutive cirrhotic patients with acute portal vein thrombosis in our institute from January 2020 to December 2021. The patients received oral anticoagulation with rivaroxaban or dabigatran. The demographic, clinical, and imaging data of patients were collected. The diagnosis of acute PVT was confirmed by imaging examinations. The severity of liver cirrhosis was assessed using Child-Pugh score and Model for End-Stage Liver Disease (MELD) score. Outcomes included recanalization (complete, partial, and persistent occlusion), liver function, bleedings, and survival. The log-rank test was used to compare Kaplan-Meier distributions of time-to-event outcomes. The Cox proportional hazards model was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

A total of 94 patients were included, 52 patients (55%) received rivaroxaban and 42 (45%) with dabigatran. The complete and partial recanalization of PVT was observed in 41 patients. There was no significant difference in complete recanalization, partial recanalization, and persistent occlusion between the two groups. With multivariate analysis, D-dimer (HR 1.165, 95% CI 1.036-1.311, p = 0.011) was independent predictors of complete recanalization. The Child-Pugh score (p = 0.001) was significantly improved in both two groups after anticoagulation, respectively. However, there was no difference between the two groups. The probability of survival was 94%, 95% in the rivaroxaban and dabigatran groups (log-rank p = 0.830). Major bleedings were reported in 3 patients (6%) in rivaroxaban group and 1 patient (2%) in dabigatran group (p = 0.646). Six patients (12%) in rivaroxaban group experienced minor bleeding, and five (12%) from dabigatran group (p = 0.691).

CONCLUSIONS

The efficacy and safety were comparable between rivaroxaban and dabigatran in the treatment of cirrhotic patients with acute portal vein thrombosis. And D-dimer can contribute to the prediction of PVT recanalization in cirrhotic patients.

Analysis of the clinical characteristics of dabigatran-induced oesophagitis

OBJECTIVES

Dabigatran-induced oesophagitis has emerged in recent years. However, the incidence and clinical characteristics of patients with dabigatran-induced oesophagitis have not yet been clarified. The aim of this study was to examine the clinical characteristics of the disease.

METHODS

A retrospective analysis was undertaken of the literature on dabigatran-induced oesophagitis in Chinese and English from 2008 onwards.

RESULTS

There were 20 men (74.07%) and seven women (25.93%) in the study; their median age was 75 years (range 37-90). The main clinical symptoms were dysphagia (42.31%), odynophagia (26.92%), retrosternal pain (23.08%) and heartburn (23.08%). Endoscopy mainly showed sloughing mucosal casts (14 cases, 56%), ulcers (8 cases, 32%) and erosion (6 cases, 24%). The main injury sites were the mid to lower oesophagus (32%) and the mid oesophagus (32%). Withdrawal of dabigatran or giving the correct medication regimen resulted in rapid recovery of clinical symptoms from 1 day in some patients and up to 4 weeks, and mucosal recovery (2-5 weeks) in a median time of 3 weeks (range 0.29-48) in all patients.

CONCLUSIONS

Oesophagitis is a rare complication of dabigatran with a good prognosis. Patients should be given proper medication instructions to prevent the occurrence of dabigatran-induced oesophagitis.

A Novel Prediction Tool for Endoscopic Intervention in Patients with Acute Upper Gastro-Intestinal Bleeding

(1) Background: Predicting which patients with upper gastro-intestinal bleeding (UGIB) will receive intervention during urgent endoscopy can allow for better triaging and resource utilization but remains sub-optimal. Using machine learning modelling we aimed to devise an improved endoscopic intervention predicting tool. (2) Methods: A retrospective cohort study of adult patients diagnosed with UGIB between 2012−2018 who underwent esophagogastroduodenoscopy (EGD) during hospitalization. We assessed the correlation between various parameters with endoscopic intervention and examined the prediction performance of the Glasgow-Blatchford score (GBS) and the pre-endoscopic Rockall score for endoscopic intervention. We also trained and tested a new machine learning-based model for the prediction of endoscopic intervention. (3) Results: A total of 883 patients were included. Risk factors for endoscopic intervention included cirrhosis (9.0% vs. 3.8%, p = 0.01), syncope at presentation (19.3% vs. 5.4%, p < 0.01), early EGD (6.8 h vs. 17.0 h, p < 0.01), pre-endoscopic administration of tranexamic acid (TXA) (43.4% vs. 31.0%, p < 0.01) and erythromycin (17.2% vs. 5.6%, p < 0.01). Higher GBS (11 vs. 9, p < 0.01) and pre-endoscopy Rockall score (4.7 vs. 4.1, p < 0.01) were significantly associated with endoscopic intervention; however, the predictive performance of the scores was low (AUC of 0.54, and 0.56, respectively). A combined machine learning-developed model demonstrated improved predictive ability (AUC 0.68) using parameters not included in standard GBS. (4) Conclusions: The GBS and pre-endoscopic Rockall score performed poorly in endoscopic intervention prediction. An improved predictive tool has been proposed here. Further studies are needed to examine if predicting this important triaging decision can be further optimized.

Esophago-gastric Complications in Radiofrequency and Cryoballoon Catheter Ablation of Atrial Fibrillation

BACKGROUND

Direct comparison studies about the incidence of esophago-gastric complications between radiofrequency (RF) and cryoballoon (CB) catheter ablation (CA) for atrial fibrillation (AF) have been scarce. We sought to elucidate the relationship between the pulmonary vein isolation (PVI) modalities and esophago-gastric complications.

METHODS

The study population consisted of 254 patients who underwent CA for AF from November 2017 to October 2018. Finally, 160 patients were enrolled and divided into the RF and CB groups. Esophageal ulcers, gastric hypomotility, and exfoliative esophagitis detected by esophago-gastro-duodenoscopy were defined as esophago-gastric complications in this study.

RESULTS

The median age was 68 years old, with 34% being females. Esophago-gastric complications were observed in 42.5% of patients who underwent CA. According to the detailed esophago-gastric complications, the RF group had a higher prevalence of esophageal ulcers than the CB group (19% vs. 0%, p <0.0001). There was no significant difference between the two groups regarding gastric hypomotility and exfoliative esophagitis (18% vs. 28%; p = 0.15, 16% vs. 21%; p = 0.42, respectively).

CONCLUSIONS

Asymptomatic esophago-gastric complications were common in catheter ablation for atrial fibrillation. The incidence of esophageal ulcers was higher in the radiofrequency group than cryoballoon group, whereas the other esophago-gastric complications did not significantly differ. This article is protected by copyright. All rights reserved.

Risk of upper gastrointestinal bleeding in patients on oral anticoagulant and proton pump inhibitor co-therapy

Background

Proton pump inhibitors (PPIs) are known to reduce the risk of upper gastrointestinal bleeding in patients on oral anticoagulants, and patients are increasingly on oral anticoagulants and PPI co-therapy. However, evidence is lacking on the safety and effectiveness of oral anticoagulants when co-administered with PPIs.

Methods

Among patients initiating oral anticoagulants (warfarin and non-vitamin K antagonist oral anticoagulants [NOACs], i.e. rivaroxaban, dabigatran, apixaban, and edoxaban) during 2013–2017, those concomitantly prescribed PPIs were identified (n = 19,851). The primary endpoint was hospitalization for major upper gastrointestinal bleeding, and secondary endpoints were death and ischemic stroke.

Results

During a mean 1.4 years of follow-up, the primary endpoint occurred in 512 (2.58%) patients. Overall, NOACs were associated with lower upper gastrointestinal bleeding risk after adjustment for age, sex, comorbidities and concomitant medications (adjusted hazard ratio 0.78, 95% confidence interval 0.65–0.94), compared to warfarin. There was no significant difference in upper gastrointestinal bleeding risk among the individual NOACs. This trend of reduced risk for upper gastrointestinal bleeding in NOACs compared to warfarin was consistent for both regular and reduced doses, throughout bleeding risk groups, and other subgroup analyses. NOACs were also associated with lower risk of death compared to warfarin. The risk for ischemic stroke was not significantly different among the oral anticoagulants in patients with atrial fibrillation.

Conclusion

In patients on oral anticoagulant and PPI co-therapy, NOACs were associated with lower risk of upper gastrointestinal bleeding and mortality compared to warfarin, while there was no difference among the oral anticoagulants for stroke prevention. In patients on PPI therapy, NOACs may preferred over warfarin for decreasing risk of upper gastrointestinal bleeding and mortality.

Microscopic Esophageal Sloughing Is Not Specific to "Sloughing Esophagitis"

OBJECTIVES

"Sloughing esophagitis" (SE) is characterized by a 2-toned squamous epithelium with superficial necrotic keratinocytes overlying viable epithelium. We compared histologic and clinical findings to determine how cases clinically diagnosed as SE differed from cases with histologic sloughing but a different clinical diagnosis. In addition, we compared cases with inflammatory and noninflammatory histology.

METHODS

We searched departmental archives for esophageal biopsies with histologic sloughing features. We compared clinical and histologic findings for cases with and without clinical confirmation of SE and with and without histologic inflammation.

RESULTS

We identified 52 patients, of whom 10 (19%) had clinically diagnosed SE, 18 (35%) had another diagnosis, and 24 (46%) had an unclear diagnosis. Endoscopic sloughing tended to be reported more often in cases with SE (P = .07). Histologic features did not discriminate between SE and other etiologies. Esophagitis resolved in 18 of 31 patients with follow-up, with no difference between sloughing and nonsloughing cases (P = .26). There were no clinical differences based on inflammatory and noninflammatory histology.

CONCLUSIONS

SE has a classic microscopic appearance, but its findings are not specific, although endoscopic sloughing helps correlate histologic and clinical findings. In cases with histologic sloughing, pathologists should raise a broad differential diagnosis.

Haemorrhagic exfoliative oesophagitis associated with nasogastric tube placement

A 92-year-old man hospitalised for cerebral infarction developed haematemesis. The patient was taking low-dose aspirin and apixaban for his cerebral infarction and non-valvular atrial fibrillation. His enteral nutrition was administrated through nasogastric tube. Upper endoscopy revealed active bleeding from a protruded lesion in the upper oesophagus. The lesion was removed by washing with a water jet, followed by successful endoscopic haemostasis. Histopathological examination revealed degenerated squamous epithelium without specific findings; the diagnosis was exfoliative oesophagitis. In our case, mechanical mucosal injury caused by nasogastric tube placement may result in exfoliative oesophagitis. In addition, the use of low-dose aspirin with apixaban may have contributed to the bleeding. We then performed a wire-guided nasogastric tube placement under fluoroscopy. No further bleeding was observed, but the patient died of sepsis 1 month later. This case highlights the importance of a risk assessment and management of oesophageal complications associated with nasogastric tube placement.

Direct Oral Anticoagulants vs. Vitamin-K Antagonists in the Elderly With Atrial Fibrillation: A Systematic Review Comparing Benefits and Harms Between Observational Studies and Randomized Controlled Trials

Background: The publication of high-quality observational studies (OSs) has fueled reassessment of the treatment effects of direct oral anticoagulants (DOACs) in the elderly with atrial fibrillation (AF). Methods: The MEDLINE, EMBASE, and Cochrane Library databases were systematically searched (through July 1, 2019) for eligible OSs and randomized controlled trials (RCTs) that reported effectiveness outcomes [stroke or systemic embolism (SE)] or safety outcomes [intracranial hemorrhage (ICH), major bleeding, gastrointestinal bleeding (GIB), myocardial infarction (MI), and all-cause mortality] for DOACs and vitamin-K antagonists (VKAs) in elderly AF patients. A random-effects model was applied to calculate adjusted hazard ratios (HRs) for OSs and relative risks (RRs) for RCTs. Interaction analyses and the ratio of HR (RHR) were used to assess and compare OSs and RCTs. Results: A total of 32 studies involving 547,419 patients were included. No significant difference in treatment effect estimates was found between 27 OSs and 5 RCTs [P _interaction > 0.05 for each and all 95% confidence interval (CI) of RHR crossed 1.0]. Compared with VKAs, DOACs significantly reduced risk for stroke/SE (OSs, HR: 0.87, 95% CI: 0.81-0.94; RCT, RR: 0.82, 95% CI: 0.67-0.96), and ICH (OSs: 0.47 [0.37-0.57]; RCTs: 0.47 [0.31-0.63]), without increasing risk for GIB (OSs: 1.21 [0.98-1.43]; RCTs: 1.34 [0.91-1.77]), and all-cause mortality (OSs: 1.01 [0.92-1.11]; RCTs: 0.94 [0.87-1.00]). Among OSs, DOACs significantly decreased risk for major bleeding (0.87 [0.77-0.98]) and MI (0.89 [0.79-0.99]). It was found that dabigatran, but not other DOACs, significantly increased risk for GIB (1.48 [1.23-1.72]). Conclusions: DOACs were demonstrated to be more effective and safer than VKAs in elderly AF patients, whereas dabigatran users had a 48% increase in risk for GIB.

Symptom-based diagnostic approach for eosinophilic esophagitis

The prevalence of eosinophilic esophagitis (EoE) has been increasing in Japan. Although the diagnosis of EoE is based on simple criteria that include the presence of esophageal symptoms and esophageal eosinophilia on biopsies, there are several important issues associated with the diagnostic approach. Following an extensive literature search, the symptoms of 886 EoE cases in Japanese adults were analyzed and divided into three categories as follows: (1) typical symptoms, such as dysphagia (53%); (2) other upper GI symptoms (40%); and (3) no symptoms found during screening or medical examination, i.e., "asymptomatic esophageal eosinophilia" (19%). The diagnostic approach was reviewed according to these categories as well as according to the presence or absence of esophageal eosinophilia. The present manuscript describes the current therapeutic strategy of EoE and ultimately proposes a symptom-based diagnostic approach for EoE.

The Risks of Exfoliative Esophagitis in Patients with Atrial Fibrillation: A retrospective observational study

The aging of the population has resulted in atrial fibrillation (AF) becoming increasingly prevalent. Treatment focuses on the prevention of thromboembolism through the use of catheter ablation or drug therapy with anticoagulants, such as warfarin or direct oral anticoagulants (DOACs). Dabigatran-induced exfoliative esophagitis has been reported as a rare side effect of DOACs. Although most cases are mild, some result in severe outcomes. However, the etiology of exfoliative esophagitis remains incompletely understood. The aim of this study is to investigate the etiology of exfoliative esophagitis and identify its risk factors by observational study.The participants were 524 patients using anticoagulants who received catheter ablation for AF and subsequently underwent upper gastrointestinal endoscopy at University of Tsukuba Hospital. Exfoliative esophagitis was noted in 21 (4.0%) patients. Potential risk factors for exfoliative esophagitis were examined retrospectively by comparing patients with and without this condition across the following parameters that were extracted retrospectively from the electronic medical records: physical characteristics, comorbidities, blood-based cardiac markers, echocardiographic and endoscopic findings, and current medications.Regarding physical characteristics, patients with exfoliative esophagitis had significantly higher body weight and BMI. No association was observed between exfoliative esophagitis and comorbidities. Associations were also not found for cardiac markers, echocardiographic findings, or endoscopic findings. In terms of current medications, patients receiving oral dabigatran showed the highest prevalence of exfoliative esophagitis at 8.8% (13/148). The adjusted odds ratio of dabigatran for exfoliative esophagitis was 10.3 by multivariable logistic regression analysis.Obesity and oral dabigatran were found to be significant risk factors for exfoliative esophagitis.

Small-Bowel Lesions in Patients Taking Direct Oral Anticoagulants Detected Using Capsule Endoscopy

METHODS

This study was a prospective, open-label, nonblinded, multicenter, and observational study. From September 2013 to March 2017, patients taking DOACs were enrolled. Patients underwent VCE. The type and location of small-bowel lesions were registered. Also, (1) the proportion of lesions detected between types of DOAC was evaluated and (2) the hemoglobin (Hb) and serum ferritin levels were compared between patients with and without small-bowel lesions.

RESULTS

33 patients were enrolled, but 4 patients withdrew their consent, and VCE was performed on 29 patients. Eight, 13, and 8 patients received dabigatran, rivaroxaban, and apixaban, respectively. Small-bowel transit was complete in 27 of 29 patients (93.1%). Small-bowel lesions were detected in 23 (79.3%), redness in 12 (41.4%), erosions in 14 (48.3%), and angioectasia in 3 (10.3%) patients, and 6 patients (20.7%) had no abnormalities. Redness and erosions were detected in the upper, middle, or lower portions, but erosions tended to be less frequent in the middle portion (p = 0.25, 0.06). Angioectasia was not detected in the lower portion. No patients had active bleeding. The findings did not differ according to the drug. The relationships between the endoscopic findings and the Hb and serum ferritin levels were not significant.

CONCLUSION

Many patients taking DOACs had small-bowel lesions; however, most lesions were relatively mild. Observing small-bowel lesions over longer periods may be necessary in patients taking DOACs. This trial is registered with UMIN000011527.

[Gastrointestinal Bleeding in Patients with Coronary Heart Disease: Preventive Options]

Extensive use of antithrombotic drugs (ATD) in patients with ischemic heart disease (IHD), on the one hand, provides a considerable decrease in the risk for development of life-threatening cardiovascular complications but on the other hand, is associated with a risk of gastrointestinal bleedings (GIB), which may develop in 0.5-1.0 % of patients. In such cases, the major measures for prevention of GIB are strict adherence to indications for the ATD treatment, detection and analysis of risk factors for GIB and their elimination as far as feasible. For evaluation of GIB risk in patients with IHD, the PRECISE-DAPT and DAPT, HAS-BLED scales should be used. If the risk factors are non-modifiable the therapeutic tactics for further management of these patients should be strictly individual with determining the nature of damage, degree of a risk for present and possible complications, and the range of required therapeutic and diagnostic measures. The use of ATD requires monitoring of the patient's condition to timely detect and treat GI complications.

Dabigatran-induced esophagitis: A case report

RATIONALE

Dabigatran is an anticoagulant medication that has been widely used to prevent strokes caused by atrial fibrillation, deep vein thrombosis, and pulmonary embolism. However, the potential adverse effect of dabigatran of gastrointestinal mucosal injury is often neglected, and even induces esophagitis.

PATIENT CONCERNS

A 77-year-old woman was admitted to the hospital with symptoms of progressive retrosternal pain, upper abdominal discomfort, and dysphagia.

DIAGNOSIS

Esophagogastroduodenoscopy showed longitudinal sloughing mucosal casts in the distal esophagus. Histological examination showed squamous epithelium with neutrophil infiltration, partial epithelial degeneration, and Helicobacter pylori. Based on a literature review, medical history, and imaging examination, the patient was diagnosed with dabigatran-induced esophagitis.

INTERVENTIONS

The patient recovered with standard H. pylori eradication therapy and proton pump inhibitor without discontinuing dabigatran.

OUTCOMES

After 2 weeks, the retrosternal pain and dysphagia were relieved and upper abdominal discomfort was attenuated.

LESSONS

Our case highlights the importance of physicians' awareness of the clinical and endoscopic characteristics of dabigatran-induced esophagitis and the importance of H. pylori-associated tests and eradication if necessary for patients with long-term dabigatran treatment.

Case report of lanthanum deposition in the esophagus

A 69-year-old woman had received hemodialysis for chronic renal failure and was taking lanthanum carbonate since 63 years of age. She presented with appetite loss and nausea. We performed esophagogastroduodenoscopy, which revealed multiple longitudinal white plaques in the esophagus. Lesion biopsies showed lanthanum deposition, and lanthanum carbonate was found histologically by energy-dispersive X-ray spectroscopy. The plaques of this patient appeared like those of dabigatran-induced esophagitis, and may have occurred due to long-term contact of the esophageal epithelium with lanthanum carbonate because patient spent time in lying state. Although a few studies regarding lanthanum deposition in the stomach have been conducted, there are no reports on lanthanum deposition in the esophagus. This case suggests that the presence of longitudinal white plaques in the esophagus may indicate lanthanum deposition.

Dabigatran must be used carefully: literature review and recommendations for management of adverse events

Atrial fibrillation increases the risk of stroke and death. The vitamin-K antagonist warfarin is recommended for patients with atrial fibrillation, but vitamin-K antagonists are cumbersome to use. Therefore, an effective, safe and convenient new anticoagulant is needed. Dabigatran acts by inhibiting free and fibrin-bound thrombin directly. It is an oral anticoagulant that was approved by the US Food and Drug Administration. The oral anticoagulant dabigatran has been used increasingly due to its good tolerance, predictable pharmacokinetics, effective anticoagulant effects, and absence of requirement of coagulation monitoring. However, an increasing prevalence of adverse events has been reported, some of them quite serious. Therefore, we searched and reviewed the literature on dabigatran with regard to adverse events, and proposed solutions to prevent and reduce the chance of adverse events occurring.

Association of atrial fibrillation and gastroesophageal reflux disease: Natural and therapeutic linkage of the two common diseases

Atrial fibrillation (AF) is a common arrhythmia and gastroesophageal reflux disease (GERD) is popular in Japan. The two common diseases share several predisposing factors such as lifestyle and senescence, and inflammation and oxidative stress play an important role in their development and progression. Incidental cases of AF treated successfully by proton pump inhibitor (PPI) applied for coexisting GERD have been sporadically reported. An increasing evidence indicates that GERD induces the initiation and the perpetuation of AF. This is caused by the autonomic nerve influence, mechanical compression, and propagation of local inflammation due to proximity of left atrium (LA) and lower esophagus. Meanwhile, AF also develops GERD by mechanical and inflammatory actions of LA characterized by remodeling and inflammation. The robust association of AF with GERD is not limited to their natural interaction, i.e., pharmacological or nonpharmacological treatment of AF is reported to aggravate GERD. Many cardiac drugs (anticoagulants, calcium antagonists, and nitrates) induce esophageal mucosal damage and lower esophageal sphincter relaxation promoting acid reflux. These drugs are frequently prescribed in patients with AF for stroke prevention, rate control, and for coexisting coronary heart disease. Catheter ablation also yields both GERD and esophageal thermal injury, which is a precursor lesion of atrioesophageal fistula. The notion that AF and GERD are mutually interdependent is widely and empirically recognized. However, mechanistic link of the two common diseases and objective evaluation of PPI as an adjunctive AF treatment warrant future large-scale prospective trials.

A case-control study of the risk of upper gastrointestinal mucosal injuries in patients prescribed concurrent NSAIDs and antithrombotic drugs based on data from the Japanese national claims database of 13 million accumulated patients

BACKGROUND

We aimed to identify the adverse effects of nonsteroidal anti-inflammatory drugs (NSAIDs) and antithrombotics on the upper gastrointestinal (GI) mucosa in a clinical setting as a case-control study using a large-scale medical database in Japan.

METHODS

We evaluated the risk of upper GI mucosal injuries in patients receiving NSAIDs and antithrombotics using the Japan Medical Data Center claims database with data for 13 million accumulated patients, from January 2009 to December 2014. Endoscopically evaluated upper GI mucosal injuries were peptic ulcers (n = 143,271), upper GI bleeding (n = 10,545), and gastroesophageal reflux disease (n = 154,755). For each patient, ten controls were matched by age, sex, and diagnosis month.

RESULTS

The odds ratio (OR) for peptic ulcers was 1.45, 1.31, 1.50, 1.53, and 1.62; for upper GI bleeding: 1.76, 1.62, 1.96, 1.82, and 2.38; and for gastroesophageal reflux disease: 1.54, 1.41, 1.89, 1.67, and 1.91 for NSAIDs, COX-2 selective inhibitors, low-dose aspirin, antiplatelet drugs, and anticoagulants, respectively (all statistically significant: P < 0.001). Polypharmacy with NSAIDs and antithrombotic drugs increased the risk of upper GI injuries compared with single-drug therapy. The injury risk was also increased by lifestyle-related diseases, including diabetes mellitus and hyperlipidemia.

CONCLUSIONS

This case-control study using the large organized Japanese claims database provided the risk of upper GI mucosal injuries in patients receiving NSAIDs and antithrombotic drugs.

Systematic review with meta-analysis: the risk of major gastrointestinal bleeding with non-vitamin K antagonist oral anticoagulants

BACKGROUND

Gastrointestinal (GI) bleeding is a common complication among anticoagulated patients. Non-vitamin K antagonist oral anticoagulants (NOACs) are associated with increased risk of GI (major and clinically relevant non-major) bleeding. However, more information is needed regarding severe events.

AIM

To evaluate the risk of NOACs major GI bleeding.

METHODS

We searched for phase III randomised clinical trials (RCT) evaluating NOACs (apixaban, dabigatran, edoxaban and rivaroxaban) and reporting major GI bleeding events, in MEDLINE, Cochrane Library, SciELO collection and Web of Science databases (July 2015). Meta-analysis was performed to estimate risk ratio (RR) and 95% confidence intervals (95% CIs). Heterogeneity was assessed with the I(2) test.

RESULTS

A total of 23 studies were included. Among patients with atrial fibrillation, the risk of major GI bleeding was not different between NOACs and vitamin K antagonists (VKA) (RR 1.08, 95% CI 0.85-1.36, I(2)  = 78%; 5 RCTs) or acetylsalicylic acid (RR 0.78, 95% CI 0.36-1.72; 1 RCT). Similar results were found for patients undergoing orthopaedic surgery and those with venous thromboembolism. NOACs were not found to increase the risk compared to low-molecular-weight heparin (LWMH) alone (RR 1.42, 95% CI 0.55-3.71, I(2)  = 7%; 8 RCTs), the sequential treatment with LMWH-VKA (RR 0.77, 95% CI 0.49-1.21, I(2)  = 43%; 7 RCTs) or placebo (RR 1.48, 95% CI 0.15-14.84, I(2)  = 21%; 2 RCTs).

CONCLUSION

Despite previous evidence supporting the association of non-vitamin K antagonist oral anticoagulants and overall GI bleeding, non-vitamin K antagonist oral anticoagulants are not associated with increased risk of major GI bleeding compared to other anticoagulant drugs (with known increased risk of these events).