Case Presentation: An 84-year-old woman with a history of hypertension and aortic stenosis (AS) presented with progressive dyspnea on exertion and melanotic stools for one week. The patient was admitted twice recently for similar reasons. Physical exam was remarkable for pallor and a grade 4/5 systolic murmur at the cardiac base with radiation to the carotids. Hemoglobin was 6.5 g/dL with a low MCV. Platelet count, international normalized ratio, prothrombin time, and partial thromboplastin time were within normal limits. Iron levels were consistent with iron deficiency anemia (serum iron 35 μg/dL, transferrin saturation 18%, and serum ferritin 40 ng/mL). After resuscitation the patient underwent esophagogastroduodenoscopy and colonoscopy which were not able to identify the source of bleeding. The patient underwent a transthoracic echocardiogram which revealed a valve area of 0.7 square centimeters and a mean aortic valve gradient of 40 mmHg. Heyde’s syndrome was strongly suspected given the recurrent obscure gastrointestinal hemorrhage in the setting of severe aortic stenosis. The patient was recommended for aortic valve replacement.
Discussion: The correlation between severe aortic stenosis and iron deficiency anemia secondary to chronic gastrointestinal blood loss from intestinal angiodysplasia has been well recognized and is known as Heyde’s syndrome. Heyde’s syndrome was first described in 1958 by Dr. Edward Heyde. Although the correlation of angiodysplasias and aortic stenosis is now well known, there is still some speculations as to the association being causative or coincidence. The higher propensity of bleeding risk in severe aortic stenosis is largely supported by two prevailing theories. The first is the development of an acquired Type 2 von Willebrand’s disease, also known as von Willebrand’s syndrome. Von Willebrand factor helps mediate hemostasis by promoting platelet adhesion. However, in high stress environments, such as in severe aortic stenosis, von Willebrand factor is unraveled via sheer stress rendering it ineffective and thus dramatically increasing the risk of bleeding. The second prevailing theory is that severe aortic stenosis promotes decreased gastrointestinal perfusion, and this hypoxic environment facilitates the rapid development of vascular abnormalities including angiodysplasias. The second theory is more contended as it is unclear if the association between AS and intestinal angiodysplasias is truly causative or casual. In a retrospective study by Bhutani et al, there was found to be an increased prevalence of gastrointestinal bleeding in patients with aortic stenosis but aortic stenosis was not found to be a cause of angiodysplasia. However, in another retrospective study by Greenstein et al, the relationship was found to be more causal. Though the mechanism of association is more debated, the treatment for Heyde’s syndrome is well established to be aortic valve replacement. In a retrospective study by Thompson et al. in 57 patients with Heyde’s syndrome, aortic valve replacement was found to be approximately 80% curative for eliminating the recurrence of rebleeding in up to 15 years follow up and in those patients who did have rebleeding, the risk of rebleeding was significantly reduced.
Conclusions: In conclusion, Heyde’s syndrome is a well described phenomenon with an established treatment of aortic valve replacement showing long term benefit. However, further studies are still required to delineate the association between aortic stenosis and angiodysplasias.