The natural history of occult or angiodysplastic gastrointestinal bleeding in von Willebrand disease

Did angiodysplasia associated with heyde's syndrome disappear spontaneously?: a case report

BACKGROUND

Heyde's syndrome can be easily overlooked or misjudged in clinical practice because it shares common clinical manifestations with multiple diseases as well as limited accuracy of several corresponding examinations for diagnosing Heyde's triad. Moreover, aortic valve replacement is often delayed in these patients due to the contradiction between anticoagulation and hemostasis. Herein, we present a rare case of atypical Heyde's syndrome. The patient's severe intermittent gastrointestinal bleeding was not completely cured even through a local enterectomy. In the absence of direct evidence of acquired von Willebrand syndrome (AVWS) or angiodysplasia, her long-standing gastrointestinal bleeding was finally stopped after receiving transcatheter aortic valve implantation (TAVI).

CASE PRESENTATION

A 64-year-old female suffered from refractory gastrointestinal bleeding and exertional dyspnoea. A local enterectomy was performed owing to persistent hemorrhage and repeated transfusions; subsequently, histological examination revealed angiodysplasia. Heyde's syndrome was not suspected until 3 years later, at which time the patient started bleeding again and was also found to have severe aortic valve stenosis upon echocardiography. TAVI was consequently performed when the patient was in a relatively stable condition even though the predisposition to bleed, but there was no evidence of angiodysplasia and AVWS during angiography at that time. The patient's above symptoms were significantly relieved after TAVI and followed up for 2 years without any significant ischemic or bleeding events.

CONCLUSIONS

The visible characteristics of angiodysplasia or a shortage of HMWM-vWFs should not be indispensable for the clinical diagnosis of Heyde's syndrome. Enterectomy could be a bridging therapy for aortic valve replacement in patients with severe hemorrhage, and TAVI may be beneficial for moderate to high surgical-risk patients even if they have a potential risk of bleeding.

Gastrointestinal bleeding in von Willebrand patients: special diagnostic and management considerations

INTRODUCTION

Severe and recurrent gastrointestinal (GI) bleeding caused by angiodysplasia is a significant problem in patients with von Willebrand disease (VWD) and in those with acquired von Willebrand syndrome (AVWS). At present, angiodysplasia-related GI bleeding is often refractory to standard treatment including replacement therapy with von Willebrand factor (VWF) concentrates and continues to remain a major challenge and cause of significant morbidity in patients despite advances in diagnostics and therapeutics.

AREAS COVERED

This paper reviews the available literature on GI bleeding in VWD patients, examines the molecular mechanisms implicated in angiodysplasia-related GI bleeding, and summarizes existing strategies in the management of bleeding GI angiodysplasia in patients with VWF abnormalities. Suggestions are made for further research directions.

EXPERT OPINION

Bleeding from angiodysplasia poses a significant challenge for individuals with abnormal VWF. Diagnosis remains a challenge and may require multiple radiologic and endoscopic investigations. Additionally, there is a need for enhanced understanding at a molecular level to identify effective therapies. Future studies of VWF replacement therapies using newer formulations as well as other adjunctive treatments to prevent and treat bleeding will hopefully improve care.

Real-world healthcare costs and resource utilization in patients with von Willebrand disease and angiodysplasia

OBJECTIVE

To describe the economic burden among VWD patients with angiodysplasia compared to VWD patients without angiodysplasia and the general population.

METHODS

This was a retrospective analysis using the Merative MarketScan Commercial and Medicare Databases® (January 2011-September 2020). Selected patients had ≥1 medical claim for VWD or low VWF, ≥1 medical claim for AGD, and ≥3 GI-related bleeding episodes within a year. HCRU and all-cause costs were compared with the VWD (only) and the general cohorts.

RESULTS

The mean total all-cause costs were $150,101 among patients with VWD and angiodysplasia (n = 34), higher compared to $48,249 among matched VWD patients without angiodysplasia (n = 136) and $31,029 among matched individuals of the general population [n = 136; p-value < 0.0001]. The differences in costs between groups were primarily due to inpatient care. During the 12-month follow-up, VWD patients with symptomatic (n = 35), asymptomatic (n = 81), and suspected (n = 378) angiodysplasia had an average of 4.1, 0.6, and 3.8 gastrointestinal (GI) bleeds, respectively. Desmopressin, VWF concentrates, and aminocaproic acid were the most frequent treatments used. The most frequent procedures to treat GI-related bleeding and underlying lesions were blood transfusion and laser therapy.

CONCLUSIONS

Despite recent therapeutic advances, there is room for considerable reduction of the disease burden in patients with VWD and angiodysplasia.

Special considerations in GI bleeding in VWD patients

Gastrointestinal (GI) bleeding is an important cause of morbidity and mortality in von Willebrand disease (VWD). It has been noted that GI bleeding caused by angiodysplasia is overrepresented in VWD patients compared to other causes. The bleeding from angiodysplasia is notoriously difficult to treat; recurrences and rebleeds are common. A growing body of basic science evidence demonstrates that von Willebrand factor negatively regulates angiogenesis through multiple pathways. VWD is clinically highly associated with angiodysplasia. The predisposition to angiodysplasia likely accounts for many of the clinical difficulties related to managing GI bleeding in VWD patients. Diagnosis and treatment are challenging with the current tools available, and much further research is needed to further optimize care for these patients with regard to acute treatment, prophylaxis, and adjunctive therapies. In this review we provide an overview of the available literature on GI bleeding in VWD and explore the molecular underpinnings of angiodysplasia-related GI bleeding. Considerations for diagnostic effectiveness are discussed, as well as the natural history and recurrence of these lesions and which therapeutic options are available for acute and prophylactic management.

Von Willebrand Disease—Specific Aspects in Women

Von Willebrand disease (VWD) is the most common inherited bleeding disorder, which results from a deficiency or dysfunction of von Willebrand factor (VWF). The major symptoms of patients affected by VWD include mucocutaneous and gastrointestinal bleeding, easy bruising, and prolonged provoked bleeding due to injury or surgery. Although women and men are equally likely to be affected by VWD, women continue to be disproportionately affected by the bleeding challenges. Women with VWD suffer from sex-specific symptoms, such as menorrhagia, and are at higher risk of reproductive problems and recurrent miscarriage. Furthermore, pregnant women with VWD are more likely at higher risk of suffering from primary and secondary peripartal hemorrhage and anemia and the need for transfusions. Despite being affected by gynecologic and obstetrical bleeding, women face multiple barriers in obtaining an accurate diagnosis. This constitutes a problem that needs to be addressed, and early appropriate medical care should be ensured. There are several effective treatment options for women with VWD that can significantly improve their quality of life, including desmopressin, VWF concentrates, hormonal therapy, and antifibrinolytic therapy. During pregnancy, the monitoring of VWF activity levels is essential. The peripartal management depends on the type of VWD and on the measured levels of VWF levels and activity prior to delivery.

Gastrointestinal Bleeding in Congenital Bleeding Disorders

Gastrointestinal bleeding (GIB) is serious, intractable, and potentially life-threatening condition. There is considerable heterogeneity in GIB phenotypes among congenital bleeding disorders (CBDs), making GIB difficult to manage. Although GIB is rarely encountered in CBDs, its severity in some patients makes the need for a comprehensive and precise assessment of underlying factors and management approaches imperative. Initial evaluation of GIB begins with assessment of hematological status; GIB should be ruled out in patients with chronic anemia, and in presentations that include hematemesis, hematochezia, or melena. High-risk patients with recurrent GIB require urgent interventions such as replacement therapy for treatment of coagulation factor deficiency (CFD). However, the best management strategy for CFD-related bleeding remains controversial. While several investigations have identified CBDs as potential risk factors for GIB, research has focused on assessing the risks for individual factor deficiencies and other CBDs. This review highlights recent findings on the prevalence, management strategies, and alternative therapies of GIB related to CFDs, and platelet disorders.

Vascular abnormalities in patients with von Willebrand disease: A scoping review

BACKGROUND

Qualitative or quantitative defects of von Willebrand factor (VWF) such as in von Willebrand disease (VWD) are associated with vascular abnormalities, especially in the gastrointestinal (GI) tract. However, the locations, extent, and natural history of vascular abnormalities in patients with VWD is not well understood. To summarize the existing literature on the topic, we conducted a scoping review of vascular abnormalities in patients with VWD.

METHODS

We searched MEDLINE and EMBASE from inception to September 1, 2020, for studies clinically describing vascular abnormalities in VWD patients. Screening and data extraction was completed independently and in duplicate and each abnormality was documented individually.

RESULTS

After screening, 54 studies that reported patient level data comprising 146 patients were included. Type 2A (39%) and type 3 (14.4%) were the most common VWD subtypes. The most common site of vascular malformation was the GI tract, occurring in 124 patients (84.9%), whereas 18 (12.3%) had non-GI vascular abnormalities and 4 (2.7%) had both GI and non-GI vascular abnormalities. With respect to outcomes, the clinical course was not specified in the majority (55.5%) of patients. Survey and population level data were reported in nine studies, demonstrating vascular abnormalities occurred at higher rates in VWD and that VWD patients are overrepresented among those with those abnormalities.

CONCLUSION

Vascular malformations in patients with VWD occur primarily in the gastrointestinal tract. Type 2A and type 3 VWD are the most common subtypes affected. The clinical treatment and natural history of these abnormalities remains understudied and further research is needed.

How I treat gastrointestinal bleeding in congenital and acquired von Willebrand disease

Gastrointestinal (GI) bleeding is distinctive of severe von Willebrand disease (VWD), generally arising in older patients; in most cases, blood transfusion and hospitalization are required. The presence of arteriovenous malformations is often described when endoscopic examinations are performed. Patients with congenital type 3, 2A, and 2B are those most frequently affected by this symptom, possibly due to the loss of high-molecular-weight multimers of von Willebrand factor (VWF). GI bleeding can also occur in patients affected by acquired von Willebrand syndrome. Endoscopic examination of the GI tract is necessary to exclude ulcers and polyps or cancer as possible causes of GI bleeding. In congenital VWD, prophylaxis with VWF/factor VIII concentrates is generally started after GI-bleeding events, but this therapy is not always successful. Iron supplementation must be prescribed to avoid chronic iron deficiency. Possible rescue therapies (high-dose statins, octreotide, thalidomide, lenalidomide, and tamoxifen) were described in a few case reports and series; however, surgery may be necessary in emergency situations or if medical treatment fails to stop bleeding. In this article, we present several clinical cases that highlight the clinical challenges of these patients and possible strategies for their long-term management.

Gastrointestinal bleeding from angiodysplasia in von Willebrand disease: Improved diagnosis and outcome prediction using videocapsule on top of conventional endoscopy

BACKGROUND

Despite a high prevalence of angiodysplasia, no specific guidelines are available for the modalities of endoscopic exploration of gastrointestinal (GI) bleeding in von Willebrand disease (VWD). Whether VWD patients could benefit from video capsule endoscopy (VCE) looking for angiodysplasia eligible to endoscopic treatment or at high risk of bleeding is unknown.

OBJECTIVES

To assess the diagnostic efficacy for angiodysplasia and the prognostic value of VCE on top of conventional endoscopy in VWD patients with GI bleeding.

PATIENTS/METHODS

A survey was sent to the 30 centers of the French-network on inherited bleeding disorders to identify VWD patients referred for endoscopic exploration of GI bleeding from January 2015 to December 2017. Data obtained included patient characteristics, VWD phenotype/genotype, GI bleeding pattern, results of endoscopic investigations, and medical management applied including endoscopic therapy. We assessed by Kaplan-Meier analysis the recurrence-free survival after the first GI bleeding event according to endoscopic categorization and, in patients with angiodysplasia, to the presence of small-bowel localizations on VCE exploration.

RESULTS

GI bleeding source localization was significantly improved when including VCE exploration (P < .01), even in patients without history of angiodysplasia (P < .05). Patients with angiodysplasia had more GI bleeding recurrences (P < .01). A lower recurrence-free survival was observed in patients with angiodysplasia (log-rank test, P = .02), and especially when lesions were located in the small bowel (log-rank test, P < .01), even after endoscopic treatment with argon plasma coagulation (log-rank test, P < .01).

CONCLUSION

VCE should be more systematically used in VWD patients with unexplained or recurrent GI bleeding looking for angiodysplasia eligible to endoscopic treatment or at high risk of relapse.

ASH ISTH NHF WFH 2021 guidelines on the management of von Willebrand disease

BACKGROUND

von Willebrand disease (VWD) is a common inherited bleeding disorder. Significant variability exists in management options offered to patients.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH), the International Society on Thrombosis and Haemostasis (ISTH), the National Hemophilia Foundation (NHF), and the World Federation of Hemophilia (WFH) are intended to support patients, clinicians, and health care professionals in their decisions about management of VWD.

METHODS

ASH, ISTH, NHF, and WFH formed a multidisciplinary guideline panel. Three patient representatives were included. The panel was balanced to minimize potential bias from conflicts of interest. The University of Kansas Outcomes and Implementation Research Unit and the McMaster Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline development process, including performing and updating systematic evidence reviews (through November 2019). The panel prioritized clinical questions and outcomes according to their importance to clinicians and patients. The panel used the GRADE approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 12 recommendations and outlined future research priorities.

CONCLUSIONS

These guidelines make key recommendations regarding prophylaxis for frequent recurrent bleeding, desmopressin trials to determine therapy, use of antiplatelet agents and anticoagulant therapy, target VWF and factor VIII activity levels for major surgery, strategies to reduce bleeding during minor surgery or invasive procedures, management options for heavy menstrual bleeding, management of VWD in the context of neuraxial anesthesia during labor and delivery, and management in the postpartum setting.

Management of von Willebrand disease with a factor VIII-poor von Willebrand factor concentrate: Results from a prospective observational post-marketing study

BACKGROUND

A triple-secured plasma-derived von Willebrand factor (pdVWF) almost devoid of factor VIII (FVIII):WILFACTIN® , was approved in France in 2003, and then in other countries for the treatment of patients with von Willebrand disease (VWD).

OBJECTIVE

To investigate long-term safety and efficacy of the product in real-life over the first 5 post-approval years.

PATIENTS/METHODS

This prospective, observational, national post-marketing study (PMS) enrolled patients of all ages and VWD types. Patients were observed for up to 3 years and treated for one or more occasions. Efficacy was assessed for each major event. Breakthrough bleeding rate 3 days post-infusion and annualized bleeding rate (ABR) were also evaluated for long-term prophylaxis.

RESULTS

Overall, 155 of 174 patients enrolled from 31 centers were eligible for efficacy assessment. Most patients (76.8%) were severely affected (VWF:RCo ≤ 15 IU/dL). They were treated for 743 bleeds and 140 surgeries including childbirth. Efficacy outcomes were excellent/good for 98.2% of 56 major surgeries and 94.0% of 67 major bleeds. Approximately 75% of 49 major mucosal bleeds were effectively managed without FVIII co-administration. In 32 patients receiving prophylaxis, breakthrough bleeding occurred in 1.5% of infusions and median ABR was 1.0 for 20 patients treated ≥ 12 months. Excellent tolerability was confirmed with no safety concerns. No thrombotic events were observed.

CONCLUSIONS

Results from this PMS increase the clinical experience of a FVIII-poor pdVWF in patients of all ages and VWD types including those with thrombotic risk factors and emphasize that giving FVIII is not always mandatory to effectively treat patients with severe VWD.

Anticoagulant treatment and bleeding complications in patients with left ventricular assist devices

INTRODUCTION

The treatment options for advanced heart failure patients drastically changed with the introduction of left ventricular assist devices (LVADs), either as bridge to transplant or as destination therapy for patients ineligible for transplant. Despite major benefits in terms of survival, functional status and quality of life, managing patients with LVADs comes with several challenges. The most significant challenge is balancing between the risks of thrombotic and bleeding complications.

AREAS COVERED

The present review describes the pathophysiological mechanisms explaining the alterations in the hemostatic profile of LVAD patients, and summarizes current evidence to guide clinical decision making with regard to anticoagulant treatment and management of bleeding complications.

EXPERT OPINION

LVAD patients require life-long anticoagulant therapy to reduce the risk of pump thrombosis. However, exposing LVAD patients to anticoagulant therapy, in combination with common acquired coagulopathies after LVAD implantation such as acquired von Willebrand syndrome, comes with high risks of bleeding. There is a need for randomized controlled trials in LVAD patients to determine the optimal antithrombotic regimen and find the most effective balance between thrombotic and bleeding complications. In addition, strategies to specifically target the acquired von Willebrand syndrome and its associated angiodysplasias need to be evaluated in the LVAD population.

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.

How I manage severe von Willebrand disease

Von Willebrand disease (VWD) is the most common inherited bleeding disorder. Most patients with mild and moderate VWD can be treated effectively with desmopressin. The management of severe VWD patients, mostly affected by type 2 and type 3 disease, can be challenging. In this article we review the current diagnosis and treatment of severe VWD patients. We will also discuss the management of severe VWD patients in specific situations, such as pregnancy, delivery, patients developing alloantibodies against von Willebrand factor and VWD patients with recurrent gastrointestinal bleeding. Moreover, we review emerging treatments that may be applied in future management of patients with severe VWD.

Recurrent Gastrointestinal Bleeding from Dieulafoy's Lesions in a Patient with Type 1 von Willebrand Disease: A Rare Association

Von Willebrand disease (vWD) is the most prevalent hereditary bleeding disorder, affecting 0.6-1.3% of the population. While gastrointestinal bleeding from angiodysplasia is a well-known complication of vWD, the same is not true for Dieulafoy's lesions (DLs). We report the case of a 21-year-old black male with type 1 vWD and 2 previous hospital admissions for severe anemia with no visible blood loss. In both episodes, DLs were identified and treated endoscopically, one in the stomach and another in the duodenum. The patient presented to the emergency department in September 2016 with dizziness, fatigue, and again no visible blood loss. He was hemodynamically stable, and laboratory workup showed a hemoglobin level of 3.4 g/dL. After transfusion of packed red blood cells, intravenous iron, and von Willebrand factor/factor VIII concentrate infusions, the patient underwent upper endoscopy and colonoscopy, which were normal. Small-bowel capsule endoscopy showed dark blood and a fresh clot in the proximal jejunum. At this site, push enteroscopy identified a pulsatile vessel with an overlying minimal mucosal defect, consistent with a DL, type 2b of the Yano-Yamamoto classification, which was successfully treated with adrenaline and 2 hemoclips. The patient remains stable after 18 months of follow-up, with a hemoglobin level of 13.2 g/dL. This is a case of recurrent severe occult gastrointestinal bleeding from multiple DL in a young patient with vWD who is otherwise healthy. Three other cases of DL bleeding in the setting of vWD have been reported in the literature, suggesting a possible association between these 2 entities.

A Risk Assessment of Factors for the Presence of Angiodysplasias During Endoscopy and Factors Contributing to Symptomatic Bleeding and Rebleeds

BACKGROUND

Few studies have assessed factors associated with angiodysplasias during endoscopy or factors associated with symptomatic disease.

AIMS

To evaluate risk factors for the presence of and contribution to symptomatic disease in patients with angiodysplasias.

METHODS

We performed a systematic MEDLINE, EMBASE and Cochrane Library search according to the PRISMA guidelines for studies assessing risk factors involved in angiodysplasias detected during endoscopy and factors that lead to anemia or overt bleeding. Study quality was assessed with the Newcastle-Ottawa scale. A risk assessment was performed by selecting risk factors identified by two independent studies and/or by a large effect size.

RESULTS

Twenty-three studies involving 92,634 participants were included. The overall quality of the evidence was moderate. Risk factors for the diagnosis of angiodysplasias during endoscopy confirmed by at least two studies were increasing age (OR 1.09 per year, 95% CI 1.04-1.1), chronic kidney disease (OR 4.5, 95% CI 1.9-10.5) and cardiovascular disease (2.9, 95% CI 1.4-6.2). The risk of rebleeds was higher in the presence of multiple lesions (OR 4.2, 95% CI 1.1-16.2 and 3.8, 95% CI 1.3-11.3 and 8.6, 95% CI 1.4-52.6), liver cirrhosis (OR 4.0, 95% 1.1-15.0) and prothrombin time < 30% (OR 4.2, 95% 1.1-15.4) with a moderate effect size. Multiple comorbidities were associated with an increased in-hospital mortality (OR 2.29, 95% CI 1.2-4.3).

CONCLUSIONS

This systematic review identified age, chronic kidney disease and cardiovascular disease as the most important risk factors for the diagnosis of angiodysplasias during endoscopy. Multiple lesions increase the risk of recurrent bleeding.

von Willebrand factor deficiency does not influence angiotensin II-induced abdominal aortic aneurysm formation in mice

Abdominal aortic aneurysm (AAA) refers to a localized dilation of the abdominal aorta that exceeds the normal diameter by 50%. AAA pathophysiology is characterized by progressive inflammation, vessel wall destabilization and thrombus formation. Our aim was to investigate the potential involvement of von Willebrand factor (VWF), a thrombo-inflammatory plasma protein, in AAA pathophysiology using a dissection-based and angiotensin II infusion-induced AAA mouse model. AAA formation was induced in both wild-type and VWF-deficient mice by subcutaneous implantation of an osmotic pump, continuously releasing 1000 ng/kg/min angiotensin II. Survival was monitored, but no significant difference was observed between both groups. After 28 days, the suprarenal aortic segment of the surviving mice was harvested. Both AAA incidence and severity were similar in wild-type and VWF-deficient mice, indicating that AAA formation was not significantly influenced by the absence of VWF. Although VWF plasma levels increased after the infusion period, these increases were not correlated with AAA progression. Also detailed histological analyses of important AAA hallmarks, including elastic degradation, intramural thrombus formation and leukocyte infiltration, did not reveal differences between both groups. These data suggest that, at least in the angiotensin II infusion-induced AAA mouse model, the role of VWF in AAA pathophysiology is limited.

[Von Willebrand disease]

Von Willebrand factor is involved in primary hemostasis (adhesion of platelets to subendothelium and platelet aggregation) and acts as the carrier of coagulation factor VIII. Von Willebrand disease, resulting from a quantitative or qualitative defect of this factor, is the most frequent inherited bleeding disorder. It is mainly responsible for symptoms such as mucocutaneous bleeding and excessive bleeding after trauma or invasive procedures, but can also cause gastro-intestinal bleeding or hemarthrosis in the most severe forms of the disease. There are numerous causes of physiological variation of von Willebrand factor plasma levels which can be responsible for diagnostic difficulty or changes in symptoms over time. Diagnosis relies primarily on clinical symptoms but requires the use of several laboratory analyses: von Willebrand factor activity and antigen testing and factor VIII activity. More specialized assays allow classification of the disease in various types and subtypes which imply different management strategies (types 1, 2A, 2B, 2M, 2N, and 3). Treatment is based on desmopressin, responsible for an increase in plasma concentration of von Willebrand factor, and plasma-derived von Willebrand factor concentrates which can be combined with factor VIII.

von Willebrand factor regulation of blood vessel formation

Several important physiological processes, from permeability to inflammation to hemostasis, take place at the vessel wall and are regulated by endothelial cells (ECs). Thus, proteins that have been identified as regulators of one process are increasingly found to be involved in other vascular functions. Such is the case for von Willebrand factor (VWF), a large glycoprotein best known for its critical role in hemostasis. In vitro and in vivo studies have shown that lack of VWF causes enhanced vascularization, both constitutively and following ischemia. This evidence is supported by studies on blood outgrowth EC (BOEC) from patients with lack of VWF synthesis (type 3 von Willebrand disease [VWD]). The molecular pathways are likely to involve VWF binding partners, such as integrin αvβ3, and components of Weibel-Palade bodies, such as angiopoietin-2 and galectin-3, whose storage is regulated by VWF; these converge on the master regulator of angiogenesis and endothelial homeostasis, vascular endothelial growth factor signaling. Recent studies suggest that the roles of VWF may be tissue specific. The ability of VWF to regulate angiogenesis has clinical implications for a subset of VWD patients with severe, intractable gastrointestinal bleeding resulting from vascular malformations. In this article, we review the evidence showing that VWF is involved in blood vessel formation, discuss the role of VWF high-molecular-weight multimers in regulating angiogenesis, and review the value of studies on BOEC in developing a precision medicine approach to validate novel treatments for angiodysplasia in congenital VWD and acquired von Willebrand syndrome.

Acquired coagulopathy in patients with left ventricular assist devices

Chronic heart failure (HF) is a major emerging healthcare problem, associated with a high morbidity and mortality. Left ventricular assist devices (LVADs) have emerged as a successful treatment option for patients with end-stage HF. Despite its great benefit, the use of LVAD is associated with a high risk of complications. Bleeding, pump thrombosis and thromboembolic events are frequently observed complications, with bleeding complications occurring in over a third of the patients. Although the design of the third-generation LVAD has improved greatly, these hemostatic complications still occur. The introduction of an LVAD into the circulatory system results in an altered hematological balance as a consequence of blood-pump interactions, changes in hemodynamics, the rheology, and the concomitant need for anticoagulation while implanted with an LVAD. The majority, if not all, LVAD patients experience a form of platelet dysfunction and impaired von Willebrand factor activity, leading to acquired coagulopathy disorders. Different diagnostic tools and treatment strategies have been reported; however, they require validation in LVAD patients. The present review focuses on acquired coagulopathies, describing the incidence, impact and underlying mechanism of acquired coagulopathy disorders in patients supported by LVADs. In addition, we will discuss diagnostic and management strategies for these acquired coagulopathies.

Platelet Secretion Defects and Acquired von Willebrand Syndrome in Patients With Ventricular Assist Devices

Background

The number of implanted ventricular assist devices (VADs) has increased significantly recently. Bleeding, the most frequent complication, cannot be solely attributed to anticoagulation therapy. Acquired von Willebrand syndrome (AVWS) caused by increased shear stress is frequent in VAD patients and can increase the bleeding risk. The HeartMate III (HM III) is a novel left VAD featuring potential improvements over the HeartMate II.

Methods and Results

In this study, we investigated the prevalence and onset of AVWS in 198 VAD patients. To our knowledge, this is the largest cohort of VAD patients whose longitudinal data on AVWS have been collected. We also analyzed whether AVWS is less severe in HM III patients than in HeartMate II patients. Because platelet dysfunction can raise the bleeding risk, we investigated platelet function in a subset of patients. In total, 198 VAD patients and 60 patients with heart transplants as controls were included in this study. The ratio of von Willebrand factor collagen binding capacity to von Willebrand factor:antigen, multimer analyses, and platelet function (especially secretion of α‐ and δ‐granules) were investigated. All 198 VAD patients developed AVWS. As soon as the VAD was explanted, the AVWS disappeared within hours. AVWS was less severe in the HM III patients than in the HeartMate II patients. The HM III patients had fewer bleeding symptoms. In addition, VAD patients exhibited a platelet α‐ and δ‐granule secretion defect.

Conclusions

AVWS develops in VAD patients and may increase the bleeding risk. The HM III device causes less severe AVWS. Platelet secretion defects should be investigated in VAD patients because they also raise the bleeding risk.

Clinical Trial Registration

https://www.drks.de/drks_web. Unique identifier: DRKS00000649.

Current and Emerging Options for the Management of Inherited von Willebrand Disease

Von Willebrand disease (VWD) is the most common inherited bleeding disorder with an estimated prevalence of ~1% and clinically relevant bleeding symptoms in approximately 1:10,000 individuals. VWD is caused by a deficiency and/or defect of von Willebrand factor (VWF). The most common symptoms are mucocutaneous bleeding, hematomas, and bleeding after trauma or surgery. For decades, treatment to prevent or treat bleeding has consisted of desmopressin in milder cases and of replacement therapy with plasma-derived concentrates containing VWF and Factor VIII (FVIII) in more severe cases. Both are usually combined with supportive therapy, e.g. antifibrinolytic agents, and maximal hemostatic measures. Several developments such as the first recombinant VWF concentrate, which has been recently licensed for VWD, will make a more "personalized" approach to VWD management possible. As research on new treatment strategies for established therapies, such as population pharmacokinetic-guided dosing of clotting factor concentrates, and novel treatment modalities such as aptamers and gene therapy are ongoing, it is likely that the horizon to tailor therapy to the individual patients' needs will be extended, thus, further improving the already high standard of care in VWD in most high-resource countries.

Thalidomide for the Treatment of Gastrointestinal Bleeding Due to Angiodysplasia in a Patient with Glanzmann's Thrombasthenia

Angiodysplasia is a frequent cause of persistent gastrointestinal (GI) hemorrhage in elderly patients. Although GI bleeding isn't the most common manifestation in patients with bleeding disorders, when present, it represents a challenging complication. We describe a 62-year-old patient with Glanzmann's thrombasthenia, who used thalidomide for severe and recurrent GI bleeding. For 6 months, the patient experienced temporary control of GI bleeding with thalidomide in a daily oral dose of 100 mg. The anti-angiogenic effects of thalidomide have recently been explored by several groups, particularly in the management of bleeding from angiodysplasia, including cases with von Willebrand disease. Here, we review the relevant descriptions of the use of thalidomide in this situation, and also discuss potential reasons why we observed only a temporary control of the GI bleeding in our patient, such as the use of low-dose regimen due to limitations posed by thalidomide side effects.

Current challenges in the diagnosis and management of patients with inherited von Willebrand's disease in Italy: an Expert Meeting Report on the diagnosis and surgical and secondary long-term prophylaxis

Recent advances in the care of von Willebrand's disease (vWD) have allowed the majority of patients to be managed adequately. Even in the more severe forms, it is now possible to control recurrent bleeding through secondary long-term prophylaxis with von Willebrand factor-containing concentrates. Moreover, in the setting of surgical prophylaxis, the combination of interdisciplinary management and close patient monitoring yields a positive outcome in nearly all cases, although safety concerns remain. In clinical practice, the effectiveness of therapy is hindered by the difficulties in making a rapid, yet accurate diagnosis, in identifying the subgroup of bleeders who may benefit most from a specific strategy, and in selecting the optimal product and regimen.Since specific guidelines for heavy bleeders requiring short- and long-term prophylaxis are still lacking, sharing the experience of experts dealing with vWD patients on a daily basis is crucial to fill gaps in information relating to patient management. To address this important issue, 13 Italian haematologists met in Milan on April, 2, 2016 and in Florence on July, 9, 2016. A 30-question survey constituted the input to discuss (i) optimisation of the diagnostic workflow for vWD, (ii) the characteristics of patients who may benefit from secondary long-term prophylaxis (in particular with the purified von Willebrand factor concentrate with a low content of factor VIII), (iii) the key elements to consider when selecting a concentrate and (iv) the pre-operative and post-operative management of vWD patients. A summary of the main points covered is provided in this report.

Angiodysplasia in von Willebrand Disease: Understanding the Clinical and Basic Science

Severe and intractable gastrointestinal bleeding caused by angiodysplasia is a debilitating problem for up to 20% of patients with von Willebrand disease (VWD). Currently, the lack of an optimal treatment for this recurrent problem presents an ongoing challenge for many physicians in their management of affected patients. Over the past few years, studies have pointed to a regulatory role for the hemostatic protein, von Willebrand factor (VWF), in angiogenesis, providing a novel target for the modulation of vessel development. This article will review the clinical implications and molecular pathology of angiodysplasia in VWD.

Recombinant von Willebrand factor for severe gastrointestinal bleeding unresponsive to other treatments in a patient with type 2A von Willebrand disease: a case report

A recombinant von Willebrand factor (rVWF) was recently approved in the United States for on-demand treatment and control of bleeding episodes in adults with von Willebrand disease (VWD). In contrast to plasma-derived VWF products available in the United States, rVWF does not contain factor VIII (FVIII). To date, there is no published experience of rVWF in clinical practice. We report the acute and prophylactic use of rVWF in a patient with VWD type 2A and severe gastrointestinal bleeding. Dosing with plasma-derived VWF/FVIII concentrates was constrained by FVIII accumulation; the bleeding was unresponsive, and multiple red blood cell transfusions were required. After initiation of rVWF (4200 IU every other day), bleeding symptoms subsided, and no red blood cell transfusions were required during more than 3 months of prophylactic therapy (most recent dosage: 2800 IU every other day). rVWF may be effective in the prevention, as well as treatment, of severe bleeding symptoms in VWD.

High variation in treatment strategies for gastrointestinal angiodysplasias

OBJECTIVE

Angiodysplasias (ADs) are the second leading cause of gastrointestinal bleeding in the elderly. The impact extends from no symptoms to chronic anaemia. Treatment guidelines are lacking. The aim of this study was to assess the current practice of gastrointestinal ADs and explore possible new research areas. On the basis of existing evidence, we would like to propose a treatment algorithm.

METHODS

We administered a 19-item web-based survey to gastroenterologists in the Netherlands between February and April of 2015.

RESULTS

A total of 111 (response rate 28%) gastroenterologists completed the survey (mean age=47 years; 24% women). The respondents identified Von Willebrand disease (17%), chronic kidney disease (21%) and aortic stenosis (77%) as risk factors for the development of ADs. Colonoscopy (54%) and esophagogastroduodenoscopy (43%) were the preferred first tools to screen for ADs. The favoured (77%) first treatment option is endoscopic argon plasma coagulation, whereas 20% start iron supplementation or blood transfusions. Treatment strategy is mostly (65%) based on the location of the ADs. Small bowel ADs are considered the most difficult to treat, because of the need for balloon enteroscopy. Of the gastroenterologists, 13% would treat ADs as a coincident finding during endoscopy. Medical therapy is mostly started in refractory ADs, and thalidomide (40%) is preferred over octreotide (19%). Thalidomide is more preferred by gastroenterologists working in a teaching hospital.

CONCLUSION

Identification of risk factors and treatment of ADs vary widely between gastroenterologists in the Netherlands. Further research is needed to create an evidence-based guideline and thereby optimize the management of symptomatic ADs.