Gastrointestinal Bleeding Due to Angiodysplasia in Patients with CKD

Angiodysplasia is an important cause of acute and chronic gastrointestinal (GI) bleeding.1 It can occur throughout the GI tract, more frequently seen in the cecum and right colon, but may also be found in small bowel and stomach. Clinical presentation ranges from overt bleeding to occult blood loss or subtle iron deficiency anemia, often resulting in recurrent bleeding over weeks or months, or persistent iron deficiency despite iron supplementation.2 Angiodysplasia has been described as a common type of GI bleeding requiring hospitalization in patients with advanced CKD.3,4 Pathogenesis is multifactorial, including chronic mucosal hypoxia, vascular degeneration, uremia-related platelet dysfunction, which increase the risk of bleeding.5 In addition, anticoagulation, commonly used in this population, makes bleeding more pronounced. The prevalence and risk of bleeding increase with the length and severity of renal disease, especially with the vintage of patients on hemodialysis.6 Endoscopy plays a central role in the diagnosis and management of angiodysplasia-associated GI bleeding (AGIB); however, lesions can sometimes be missed,2 particularly in the small bowel because of lack of visualization. In patients with CKD, angiodysplasias are most frequently found in the jejunum.4 In addition to the difficult location of angiodysplasias in this population, Garg et al. described that patients with advanced CKD and ESKD are less likely to receive endoscopic assessments, despite their increased mortality risk.7 Tariq et al.8 examined the US Nationwide Inpatient Sample (NIS) database from 2009 to 2014, and demonstrated an increasing trend of AGIB in patients with ESKD, with elevated risk factors linked to advanced age, Black race, hypertension, and smoking. Individuals aged 75 and older were particularly at higher risk. The likelihood of AGIB was significantly higher among hospitalizations of Black patients. Recently, He et al.9 conducted a retrospective study using the NIS database from 2016 to 2019 to evaluate inpatient outcomes of all-cause GI bleeding in patients with advanced CKD, ESKD, and kidney transplant recipients, compared with those without CKD. They found that nonvariceal upper GI bleeding was the most common cause of GI bleeding in all patients (38.7%). Among patients with advanced CKD, unspecified GI bleeding was most frequent, followed by nonvariceal GI bleed. After excluding unspecified gastrointestinal bleeding, the main causes were gastric/duodenal bleeding, angiodysplasia, and diverticular bleeding. Notably, patients with ESKD were less likely to undergo an endoscopy, and among those who did, the procedure was usually performed more than 48 hours after admission, showing a delay in diagnosis and management for this population. By contrast, kidney transplant recipients received similar management to patients without CKD. Several factors may contribute to these disparities, including the greater clinical complexity and higher comorbidity burden in patients with ESKD, which can increase the procedural risk. In addition, delayed recognition of GI bleeding may occur because of subtle or nonspecific symptoms, with anemia often attributed to chronic disease rather than active bleeding. In this issue, He et al.10 conducted a retrospective cohort study of using the 2022 NIS database and the Nationwide Readmissions Database to evaluate the incidence, outcomes, and readmissions associated with AGIB in patients with CKD. International Classification of Diseases-10 clinical modification codes were used to identify adult patients hospitalized with AGIB, and they were stratified into patients with no CKD, early CKD (stage 3), advanced CKD (stage 4 and stage 5 not on dialysis), kidney failure (KF, ESKD, or CKD 5 requiring chronic dialysis), and others (unspecified CKD). Primary outcome was the incidence of AGIB hospitalization, and secondary outcomes were in-hospital mortality, disease severity (use of mechanical ventilation, vasopressor support, blood transfusions, etc.), treatment interventions (aterial embolixation, surgical interventions, etc.), health care utilization, and 30-day readmission. He et al.10 found that CKD was an independent risk factor for hospitalization because of AGIB, with the risk progressively increasing according to the CKD stage. KF was independently associated with higher mortality, increased hospitalization length, and decreased likelihood of undergoing endoscopic evaluation. By contrast, endoscopic evaluation was associated with a reduced risk of mortality. The 30-day all-cause readmission was 22.3%, with recurrent AGIB being the most common reason for readmission. These findings are consistent with and build upon previous studies by the same group and others.8,9 This study had some limitations. Its retrospective observational design limits causal inference and may be subject to residual confounding. It depended on administrative claims data, which is susceptible to coding errors and lacks detailed clinical information. Although missing data were minimal (<0.9%), the reliance on International Classification of Diseases-10 Clinical Modification codes may have excluded cases where AGIB developed during hospitalization for another condition, potentially underestimating its burden. Despite the aforementioned limitations, this study by He et al.10 features important information on the CKD population, underscoring the progressively increasing risk of AGIB in patients as their CKD worsens. It allows a critical insight into how the severity of CKD directly influences the risk of acute GI bleeding, which can lead to a potentially life-threatening complication. Patients with advanced CKD, particularly those with KF, face disproportionately high risks of AGIB, yet studies have shown they are less likely to receive timely endoscopic evaluation—a key diagnostic and therapeutic intervention which is associated with improved outcomes and reduced mortality. This disparity highlights an urgent need for advocacy to promote awareness and ensure access to endoscopic care. Addressing barriers such as concerns about procedural risk, care coordination challenges, and resource limitations, will help promote early and appropriate evaluation in patients with KF leading to better clinical outcomes, reduced hospital stays, and more efficient use of health care resources. By establishing a clear, stage-dependent relationship, this study can help clinicians better identify high-risk patients, implement earlier surveillance or preventive strategies, and tailor management plans accordingly. It also highlights the need for more targeted research and resource allocation for patients with advanced CKD, who are particularly vulnerable to poor outcomes from AGIB.