Endoscopic Evaluation for Iron Deficiency Anemia in Patients on Antithrombotic Therapy

Antithrombotic therapy plays a critical role in preventing thrombotic events in patients with atherosclerotic coronary artery disease and atrial fibrillation. However, these therapies are associated with an increased risk of gastrointestinal bleeding, including obscure gastrointestinal bleeding (OGIB), which is often recurrent and linked to high morbidity and mortality.

This single-center, prospective, randomized pilot study aims to assess the feasibility and safety of two different management strategies for patients on antithrombotic therapy presenting with OGIB. Approximately 20 participants will be randomized in a 1:1 ratio into two groups:

Group A will undergo repeated gastrointestinal evaluations (e.g., endoscopy, colonoscopy, capsule endoscopy) as clinically indicated, along with iron supplementation (oral or intravenous) or blood transfusions as needed.

Group B will receive a single round of gastrointestinal evaluation, iron supplementation or transfusions as needed, and regular laboratory monitoring (hemoglobin and ferritin levels).

The primary objective is to evaluate the feasibility of conducting a larger randomized controlled trial comparing conservative medical management to standard repeated endoscopic evaluation. The secondary objective is to compare the quality of life between the two groups.

This study will also assess recruitment strategies, measurement tools, and the safety of a "watchful waiting" approach. Ultimately, the findings will help determine whether endoscopic evaluation provides clinical benefit in patients with iron-deficiency anemia on antithrombotic therapy who have had negative initial endoscopic workups. Currently, there are no established guidelines for managing recurrent iron-deficiency anemia in this population.

Inclusion criteria

• Adult men and postmenopausal women with iron deficiency anemia, and premenopausal women with iron deficiency anemia and a negative gynecological evaluation;

a. Laboratory-confirmed iron deficiency anemia (hemoglobin < 120 g/L for women, < 130 g/L for men, and ferritin < 30 ng/L);

• Patients receiving anticoagulant or antiplatelet therapy
• Negative esophagogastroduodenoscopy (EGD), colonoscopy, and capsule endoscopy for gastrointestinal bleeding within six months prior to study enrollment
• Willing and able to provide written informed consent
• Able to read and understand French

Exclusion criteria

• Ongoing overt gastrointestinal bleeding
• Acute coronary syndrome, acute neurological event, sepsis, or respiratory failure within the past week
• Pregnant women
• Known gastrointestinal or hematological malignancy
• Contraindications to capsule endoscopy
• History of bariatric surgery, gastrectomy, or segmental resection of the small intestine
• Inability to take oral iron
• Other sources of blood loss (e.g., urinary, gynecological, hematoma, hemolysis)