Aortic Valve Stenosis, a Precipitating Factor of Recurrent Bleed in Colonic Angiodysplasia: A Literature Review

Abstract

Angiodysplasia (also known as angioectasia) is a lesion characterized by abnormal, dilated small blood vessels in the mucosa and submucosal layers of the GI tract. With the estimated low incidence of active GI bleeding from these lesions, angiodysplasia can be challenging to diagnose. The presence of aortic stenosis has increased the recognition rate of angiodysplasia, especially in the elderly. Despite the associations between aortic stenosis and angiodysplasia (Heyde's syndrome) revealed in several studies, the etiology of Heyde syndrome is still debatable, which has led to the proposition of several hypotheses that are reviewed in this article. This activity will help review the meaning of Heyde's syndrome, epidemiology, proposed pathophysiology, diagnosis, and management by surveying articles published between 1955 and 2021 on PubMed. We used search terms such as "colonic angiodysplasia," "arteriovenous malformation," "Heyde syndrome," "refractory gastrointestinal bleed," "aortic valve stenosis," and "acquired von Willebrand disease." Findings revealed an association between aortic stenosis and lower gastrointestinal (GI) bleed.

Multimodal Treatment and Diagnostic Modalities in the Setting of Heyde’s Syndrome: A Systematic Review

“…This resulted in three studies being eliminated, and ultimately 18 studies were included in this systematic review. Table 1 shown below is a summary of the pertinent findings of the 18 studies that were included in this systematic review [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The aim of this prospective cohort was to ascertain the link between Von Willebrand factor levels and patients undergoing TAVI.…”

“…GIB: gastrointestinal bleeding; VWF: Von Willebrand factor; VWS: Von Willebrand factor syndrome; MGUS: monoclonal gammopathy of undetermined significance; NH-L: non-Hodgkin's lymphoma Angiodysplasia: Angiodysplasia refers to an acquired vascular aberration in which the blood vessels of the GI tract form pathological tortuous arteriovenous (AV) malformations in the mucosa and submucosa [1,2,9]. It is the second most common cause of developing a lower GI bleed in patients over the age of 60 years [10].…”

“…Loss of high molecular weight VWF multimers in Heyde's syndrome leads to increased VEGF activity and, as a result, enhanced vascular proliferation [6]. Newly formed blood vessels are fragile and may be more vulnerable to GI bleeding [10].…”

“…Heyde's syndrome is characterized by a subset of type 2 VWD called type 2A, which exhibits a lack of high molecular weight (HMW) VWF multimers [13]. VWF is stored in Weibel-Palade bodies and the alpha granules of platelets after its synthesis in endothelial cells and megakaryocytes [10,13]. These granules contain large VWF multimers, which are then cleaved into low and high molecular weight forms.…”

“…Aortic stenosis causes increased shear stress on the VWF multimers, this is due to the increased speed at which blood traverses through the valve. This shear stress leads to elongation of the VWF multimers [6,10]. These multimers typically exist in a closed globular conformation; when elongation occurs, hidden cleavage sites are exposed, making them more susceptible to proteolytic cleavage via a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) [6,14], and thus the remaining small VWF multimers are unable to induce adequate hemostasis making patients more susceptible to GI bleeding [10].…”