Contrasting Outcomes in Heyde Syndrome: Diffuse Small-Bowel Angiodysplasia Versus Treatable Colonic Angiodysplasia.

Heyde syndrome is characterized by the association of aortic stenosis, gastrointestinal bleeding from angiodysplasia, and acquired von Willebrand syndrome. We report two contrasting cases illustrating how lesion distribution and therapeutic accessibility may influence immediate bleeding management options and clinical course. The first patient was a 72-year-old male with severe calcific aortic stenosis who presented with recurrent melena and severe anemia. Upper gastrointestinal endoscopy and colonoscopy were negative, whereas capsule endoscopy revealed numerous angiodysplastic lesions diffusely distributed throughout the small bowel. Transthoracic echocardiography showed an aortic valve area of 0.72-0.74 cm², a mean transvalvular gradient of 43.40-45.16 mmHg, a peak aortic jet velocity of 4.02-4.04 m/s, and a left ventricular ejection fraction of 55%. Von Willebrand factor activity was reduced, with an activity-to-antigen ratio of 0.41. Device-assisted enteroscopy was not available at our center, limiting endoscopic therapeutic options. Despite transfusion and supportive management, persistent gastrointestinal bleeding progressed to hemorrhagic shock, and the patient died before definitive aortic valve intervention could be performed. The second patient was a 70-year-old male with severe calcific aortic stenosis who presented with recurrent hematochezia. Colonoscopy identified a localized right-colonic angiodysplasia that was successfully treated with argon plasma coagulation. Echocardiography showed an aortic valve area of 0.60 cm², a mean transvalvular gradient of 54.18 mmHg, a peak aortic jet velocity of 4.61 m/s, and a left ventricular ejection fraction of 65%. The von Willebrand factor activity-to-antigen ratio was 0.46. No recurrent gastrointestinal bleeding was documented during one year of follow-up after endoscopic treatment; however, completion of the planned aortic valve intervention could not be confirmed from the available records. These cases emphasize the importance of early recognition, lesion localization, and timely multidisciplinary management while illustrating that clinical outcome in Heyde syndrome is multifactorial.