Severity of the Loss of High Molecular Weight Multimers Is Associated with Heyde Syndrome in Patients with Severe Aortic Stenosis.
Authors: Wysokinska Ewa M. , Duello Katherine M. , Blackshear Joseph L , Stark Mark E. , Chen Dong 
Published: October 2019

Abstract
Abstract 2230

Background:
Heyde syndrome describes patients with severe aortic stenosis (AS) who have bleeding diathesis, especially gastrointestinal bleeding. Although acquired won Willebrand syndrome (AVWS) due to loss of the highest molecular weight multimers (HMWM) presents in most patients with severe AS, not all such patients develop Heyde syndrome. The goal of this study was to explore whether the severity of HMWM loss was significantly associated with Heyde syndrome.

Methods:
We first performed chart reviews on patients referred for double balloon enteroscopy (DBE) for GI bleeding or iron-deficiency anemia (GIB/FeDefic) in two time periods, from 2005–2008, and from 2009–2011. Next, patients who could have AVWS due to AS or other cardiovascular or hematologic disorders were identified. Laboratory tests including VWF antigen (VWF:Ag), VWF ristocetin cofactor activity or VWF latex immunoturgidic activity (VWF:Ltx) and/or VWF multimer analysis were performed as requested by physicians. From this population, patients with Heyde syndrome were identified. Their clinical and VWF laboratory testing results were compared to a separated group of patients with severe AS patients who had no clinically significant bleeding, but had matched gender and hemodynamic severity by echocardiogram (Matched AS Controls). These patients all had VWF:Ag, VWF:Ltx, and VWF multimers performed. In both Heyde syndrome patients and Matched AS controls, VWF multimer densitometry ratio of the HMWM (>15 mers) to low to intermediate multimers (2–15 mers) was assessed (VWF:multi ratio).

Results:
Overall, 437 patients underwent DBE for GIB/FeDef. Between 2005 and 2008, 1% of 318 patients had VWF testing. From 2009 to 2011, 23% of 119 patients were tested. Heyde syndrome was noted in 15 patients. Of the 437 patients, 134 patients (31%) likely had AVWS based on diagnoses of moderate-severe AS (30%), moderate to severe mitral regurgitation (25%), moderate to severe pulmonary hypertension (16%), prosthetic valve regurgitation or stenosis (13%), hypertrophic cardiomyopathy (10%), and hematologic disorders (4%). Among these 134 patients, 29 patients had VWF tests performed, and 22 had VWF multimer analysis. VWF antigen levels were similar in Heyde syndrome and Matched AS Controls (176±89% versus 155±77% respectively). Despite similar hemodynamic severity, more severe HMWM loss as indicated by lower VWF:Ltx/Ag and VWF:multi ratios was present in Heyde syndrome patients than matched AS controls (table, P<0.0007).

Conclusion:
If AVWS is suspected in patients with GIB/FeDef, laboratory testing for VWF indices is important to confirm the diagnosis of AVWS. Despite similar hemodynamic severity, Heyde syndrome patients have more severe VWF HMWM loss indicated by significantly decreased VWF:Ltx/VWF:Ag and VWF:multi ratios. Conversely, though highly sensitive for AVWS, PFA-CADP does not predict bleeding tendency in patients with severe AS.

Disclosures:
No relevant conflicts of interest to declare.