Thrombosis in VonWillebrand disease

Von Willebrand Disease Epidemiology, Burden of Illness and Management: A Systematic Review

Introduction

Although hereditary von Willebrand disease (VWD) is the most common bleeding disorder, its epidemiology is not well understood. A systematic review (PROSPERO CRD42020197674/CRD42021244374) on the epidemiology/burden of illness of VWD was conducted to better understand patients' unmet needs.

Methods

Observational studies (published January 1, 2010 to April 14, 2021) were identified in MEDLINE and Embase databases, using free-text keywords and thesaurus terms for VWD and outcomes of interest. Pragmatic web-based searches of the gray literature, including conference abstracts, were performed, and reference lists of retained publications were manually searched for additional sources. Case reports and clinical trials (phase 1-3) were excluded. Outcomes of interest were incidence, prevalence, mortality, patient characteristics, burden of illness, and therapeutic management/treatments currently used for VWD.

Results

Of the 3095 identified sources, 168 were included in this systematic review. Reported VWD prevalence (22 sources) ranged from 108.9 to 2200 per 100,000 in population-based studies and from 0.3 to 16.5 per 100,000 in referral-based studies. Reported times between first symptom onset and diagnosis (two sources; mean 669 days; median 3 years) highlighted gaps in timely VWD diagnosis. Bleeding events reported in 72-94% of the patients with VWD (all types; 27 sources) were mostly mucocutaneous including epistaxis, menorrhagia, and oral/gum bleeding. Poorer health-related quality of life (three sources) and greater health care resource utilization (three sources) were reported for patients with VWD than in general populations.

Conclusion

Available data suggest that patients with VWD experience high disease burden in terms of bleeding, poor quality of life, and health care resource utilization.

The Intriguing Relationships of von Willebrand Factor, ADAMTS13 and Cardiac Disease

von Willebrand factor (VWF) is an adhesive protein involved in primary hemostasis and facilitates platelet adhesion to sites of vascular injury, thereby promoting thrombus formation. VWF exists in plasma as multimers of increasing size, with the largest (high molecular weight; HMW) expressing the greatest functional activity. A deficiency of VWF is associated with a bleeding disorder called von Willebrand disease (VWD), whereas an excess of VWF, in particular the HMW forms, is associated with thrombosis. ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif-13), also known as VWF-cleaving protease, functions to moderate the activity of VWF by cleaving multimers of VWF and limiting the expression of the largest multimers of VWF. A deficiency of ADAMTS13 is therefore associated with an excess of (HMW forms of) VWF, and thus thrombosis. Indeed, any disturbance of the VWF/ADAMTS13 ratio or ‘axis’ may be associated with pathophysiological processes, including prothrombotic tendency. However, both thrombosis or bleeding may be associated with such disturbances, depending on the presenting events. This review evaluates the relationship of VWF and ADAMTS13 with cardiac disease, including cardiac failure, and associated pathophysiology.

Addressing unmet needs in rare bleeding disorders: selected poster extracts of recent research in hemophilia A and von Willebrand disease presented at the 14th Annual Congress of the European Association for Haemophilia and Allied Disorders (EAHAD) (Feb 3-5, 2021; virtual congress)

Hemophilia A and von Willebrand disease (VWD) are inherited rare bleeding disorders affecting normal hemostasis. Patients with VWD, especially those with severe disease types, share some similarities to patients with hemophilia A in their burden of disease: they suffer from an increased risk of potentially severe and life-threatening bleeds and associated long-term consequences, such as impaired joint health and overall lower quality of life. However, the two bleeding disorders differ in their primary cause and affected patient population, and comprise a range of different bleeding phenotypes with varying unmet needs. Generating scientific evidence to advance health care for patients with rare bleeding disorders is challenging due to the low prevalence and heterogeneity of affected populations, including patient demographics and symptom severities. Innovative study designs are needed to adequately answer relevant scientific questions and address patients' unmet needs. In support of advancing clinical outcomes and treatment options for these patients, at the recent EAHAD 2021 annual congress, novel approaches and data from clinical and real-world observational studies, as well as systematic literature analyses, were presented. Herein, extracts from seven selected posters reporting research in hemophilia A and VWD funded by Takeda are discussed.

Coexistence of Von Willebrand disease and gastrointestinal stromal tumor (G.I.S.T): Case report of a rare and challenge association

Von Willebrand disease (VWD) is the most common inherited bleeding disorder and is caused by a quantitative (type 1 and 3) or qualitative (type 2) defect of Von Willebrand factor (VWF). Bleeding from the gastrointestinal (GI) tract is not uncommon in VWD and is usually associated with angiodysplasia. We report herein on the management of a patient affected by VWD2B with severe GI bleeding secondary to gastrointestinal stromal tumor (GIST) complicated by deep vein thrombosis (DVT). The current case demonstrated that the hemostatic balance, in RBDs under specific circumstances, can range from a tendency toward a hemorrhagic to normal or prothrombotic state. In these patients, a close collaboration between hematologists and surgeons can guarantee appropriate management in high-risk clinical scenarios.

Von Willebrand disease in the elderly: clinical perspectives

Von Willebrand disease (VWD) is an inherited bleeding disorder that affects up to 1% of the population. In most cases, VWD results from a mutation in the von Willebrand Factor (VWF) gene, which alters the amount and function of VWF, a key glycoprotein in both primary and secondary hemostasis. A comprehensive analysis of patients with VWD should include VWF activity, antigen levels, platelet function, and a careful bleeding history. Treatment options include antifibrinolytics, desmopressin, and VWF replacement therapy. VWF levels fluctuate due to age, stress, environmental exposures, and pharmacologic treatment. Treatment guidelines exist to treat and prevent bleeding for patients undergoing surgery and medical procedures, but often these must be reevaluated in the setting of age-related comorbidities including cardiovascular events, venous thrombosis, and malignancy. In addition, many age-related complications are associated with a secondary acquired von Willebrand syndrome (AVWS), including malignancies, hypothyroidism, cardiovascular diseases, and cardiac replacement devices. The current literature is limited by a lack of older patients in clinical trials. Larger studies are needed to determine if age-related comorbidities affect VWD patients at different frequencies than the general elderly population. There is also a significant need for registry-based studies to evaluate many age-related comorbidities in VWD patients.

Interventional therapies and in-hospital outcomes in acute coronary syndromes complicated by von Willebrand disease

INTRODUCTION

von Willebrand disease (VWD) is one of the most common inherited bleeding disorders.

AIM

Investigate the impact of the VWD bleeding tendency on in-hospital management of acute coronary syndromes (ACS).

METHODS

Using discharge data from the National Inpatient Sample (NIS), the features of presentation and in-hospital treatment among ACS hospital discharges with and without a VWD diagnosis were investigated. A total of 264 case discharges and 705 860 control discharges were identified.

RESULTS AND CONCLUSIONS

There was a significantly higher percentage of women among the case discharges compared to the control discharges (59.5% and 39.4%, respectively; P < 0.001). The rate of medical therapy alone [i.e. avoidance of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)] was significantly higher among unstable angina cases than controls (55.0% vs. 46.4%; P = 0.01), and among cases undergoing PCI, bare-metal stents (BMS) were utilized in preference to drug-eluting stents (DES) (adjusted OR = 3.5); P < 0.001). No difference in in-hospital death was identified, but reported bleeding among discharges that underwent CABG was higher in cases compared to controls (12.9% vs. 5.2%; P = 0.047). Although medical and interventional management of ACS appears to be well tolerated in the majority of hospitalized patients with VWD, the gender ratio is reversed, interventions and DES are utilized less frequently and procedure-related bleeding may be increased, calling for further study.

Prevalence and Risk Factors Associated With Hypertension in von Willebrand Disease

BACKGROUND

von Willebrand factor (VWF) is a biomarker for endothelial damage. Increased VWF levels are observed in hypertension (HTN) and disorders of endothelial dysfunction, for example, atherosclerotic heart disease (ASHD) and diabetes. Whether low VWF protects against HTN is unknown.

METHODS

To determine prevalence and risk factors for HTN in patients with von Willebrand disease (VWD), we conducted a cross-sectional analysis of discharge data from the National Inpatient Sample, 2009 to 2011. Group comparisons were performed by Rao-Scott χ² test. Odds of HTN and HTN outcomes in VWD were estimated by weighted multivariable logistic regression.

RESULTS

The prevalence of hypertension in patients with VWD (N = 7556), 37.35%, was significantly lower than that in non-VWD patients (N = 19 918 970), 49.40%, P < .0001. Hypertension risk factors (hyperlipidemia, diabetes, smoking, hepatitis C, and HIV) and HTN outcomes (ASHD, myocardial infarction [MI], ischemic stroke, and renal failure) were less common in patients with VWD than in non-VWD patients, all P ≤ .0001. Patients with VWD were younger, 49.67 versus 57.30 years, Caucasian, 82.23% versus 68.35%, and female, 75.44% versus 59.61%, P < .0001. Patients with HTN were older, 67.55 versus 47.29 years, male, 45.99% versus 34.90%, and had more HTN risk factors and HTN outcomes than those without HTN, all P < .0001, including male and female subgroups, each P < .0001. The unadjusted odds of HTN in patients with VWD (odds ratio [OR] = 0.611, P < .0001) and of HTN outcomes in patients with VWD (ASHD, OR = 0.509; MI, OR = 0.422; ischemic stroke, OR = 0.521; renal failure, OR = 0.420, all P < .0001) became insignificant after adjustment for HTN risk factors plus demographics (age/race/gender), OR = 1.035, P = .260.

CONCLUSION

The risk of HTN is reduced in patients with VWD, but not after adjustment for HTN risk factors plus demographics, as patients with VWD not having HTN are also typically young, Caucasian, and female.

Myocardial Infarctions and Other Acute Coronary Syndromes in Rare Congenital Bleeding Disorders

Objective:

To investigate the occurrence of myocardial infarction or other acute coronary syndromes in rare congenital bleeding disorders.

Patients:

All patients with factor I (FI), factor II (FII), factor V (FV), factor VII (FVII), factor X (FX), factor XI (FXI), or factor XIII (FXIII) deficiency or abnormality reported to have presented a myocardial infarction or another acute coronary syndrome were investigated. The condition had to be demonstrated by objective means, including a coronary/angiography. Cases of stable angina were excluded.

Results:

A total of 53 patients (4 had FI, 2 had FV, 2 had FVII, 36 had FXI, 1 had FXIII deficiency, and 8 patients had platelet disorders) met the inclusion criteria . No patient with FII or FX deficiency and acute coronary disease met the inclusion criteria. In the majority of patients, common risk factors were present, namely hypertension, hypercholesterolemia, smoking, and diabetes. Replacement therapy was involved in 5 cases.

Conclusion:

The congenital hypocoagulability present in these patients was unable to allow a protection from acute coronary diseases. The significance of the findings is discussed.

von Willebrand factor, Jedi knight of the bloodstream

When blood vessels are cut, the forces in the bloodstream increase and change character. The dark side of these forces causes hemorrhage and death. However, von Willebrand factor (VWF), with help from our circulatory system and platelets, harnesses the same forces to form a hemostatic plug. Force and VWF function are so closely intertwined that, like members of the Jedi Order in the movie Star Wars who learn to use "the Force" to do good, VWF may be considered the Jedi knight of the bloodstream. The long length of VWF enables responsiveness to flow. The shape of VWF is predicted to alter from irregularly coiled to extended thread-like in the transition from shear to elongational flow at sites of hemostasis and thrombosis. Elongational force propagated through the length of VWF in its thread-like shape exposes its monomers for multimeric binding to platelets and subendothelium and likely also increases affinity of the A1 domain for platelets. Specialized domains concatenate and compact VWF during biosynthesis. A2 domain unfolding by hydrodynamic force enables postsecretion regulation of VWF length. Mutations in VWF in von Willebrand disease contribute to and are illuminated by VWF biology. I attempt to integrate classic studies on the physiology of hemostatic plug formation into modern molecular understanding, and point out what remains to be learned.