Acquired von Willebrand syndrome in ECMO patients: A 3-year cohort study.

BACKGROUND: Bleeding is a common but possibly underreported side effect of Extracorporeal Membrane Oxygenation (ECMO). Impairment of primary hemostasis by acquired von Willebrand syndrome (aVWS) and platelet dysfunction as well as activation and consumption of plasmatic coagulation factors contribute to hemorrhage. The aim of the present cohort study of consecutively enrolled patients admitted to our ECMO center was to collect demographic, medical and laboratory data possibly associated with i) development of clinically relevant bleeding and/or ii) death during a 12-months follow-up. RESULTS: Within a 3-year period 338 white patients aged 18-89 years (median: 60; male 64.5%) were enrolled. 78 of 338 patients (23%) presented with clinical relevant bleeding symptoms. The overall death rate was 74.6% within a median time of 9 days (1-229) post intervention. Logistic-regression analysis adjusted for age and gender revealed that i) the presence of blood group O versus non-O (Odds ratio (OR)/95%CI: 1.9/1.007-3.41), ECMO duration per day (1.1/1.06-1.14), veno-venous versus veno-arterial ECMO cannulation (2.33/1.2-4.5) and the overall need for blood product administered per unit (1.02/1.016-1.028) was independenly associated with bleeding in patients suffering from aVWS. ii) Older age (increase per year) at ECMO start (1.015/1.012-1.029) and an increasing amount of blood product units were significantly related with death (1.007/1.001-1.013). Patients with veno-venous versus veno-arterial cannulation survived longer (0.48/0.24-0.94). CONCLUSION: In the present cohort study we found a clinical relevant bleeding rate of 23% in subjects with aVWS associated with blood group O, a longer ECMO duration and veno-venous cannulation.

Diagnosis and Management of Acquired von Willebrand Disease in Heart Disease: A Review of the Literature.

The incidence of acquired von Willebrand syndrome (AvWS) in patients with heart disease is commonly perceived as rare. However, its occurrence is underestimated and underdiagnosed, potentially leading to inadequate treatment resulting in increased morbidity and mortality.In patients with cardiac disease, AvWS frequently occurs in patients with structural heart disease and in those undergoing mechanical circulatory support (MCS).The clinical manifestation of an AvWS is usually characterized by apparent or occult gastrointestinal (GI) or mucocutaneous hemorrhage frequently accompanied by signs of anemia and/or increased bleeding during surgical procedures. The primary change is loss of high-molecular weight von Willebrand factor multimers (HMWM). Whereas the loss of HMWM in patients with structural heart disease is caused by increased HMWM cleavage by von Willebrand factor (vWF)-cleaving protease, ADAMTS13, AvWS in MCS patients is predominantly a result of a high shear stress coupled with mechanical destruction of vWF itself.This manuscript provides a comprehensive review of the evidence regarding both diagnosis and contemporary management of AVWS in patients with heart disease.

Rodenticidal hepatotoxicity: Raised plasma Von Willebrand factor levels predict in-hospital survival and preliminary report of the outcome of Von Willebrand factor reducing management protocol.

BACKGROUND: High Von Willebrand factor (VWF) levels may predispose to multi-organ failure in acute liver failure (ALF). In rodenticide-induced hepatotoxicity patients, we analyzed if plasma VWF levels predicted survival and also the outcome of VWF lowering by N-acetyl cysteine (NAC), fresh frozen plasma (FFP) infusions, and plasma exchange (PLEX). METHODS: We retrospectively analyzed prospectively collected data. Hepatotoxicity was classified as uncomplicated acute hepatitis (UAH), acute liver injury (ALI), and ALF. ALF patients, if not opting for liver transplantation, had PLEX and NAC; ALI patients received NAC ± FFP (PLEX, if worsening); UAH patients had NAC. Plasma VWF antigen was measured (normal, 50% to 150%). In-hospital survival was analyzed as discharged alive or died/discharged in a terminal condition (poor outcome). RESULTS: Twenty-four consecutive rodenticide-induced hepatotoxicity patients (UAH in 1, ALI in 20, ALF in 3) from December 2017 to January 2019 were studied. Baseline VWF levels were 153%, 423 (146-890)% median (range), and 448 (414-555)% in UAH, ALI, ALF patients; model for end-stage liver disease (MELD) scores were 11, 24 (12-38), 36 (32-37) and in-hospital survival rates were 100%, 85%, 67%, respectively. VWF levels were higher in patients with poor outcome (555 [512-890]%) than in those discharged alive (414 [146-617]%) (p-value = 0.04). The area under the receiver operating curve of the VWF level, MELD score, and sequential organ failure assessment score to predict survival was 0.92, 0.84, and 0.66, respectively. Of 4 patients meeting criteria for liver transplantation (none had transplantation), 3 (75%) survived. CONCLUSIONS: High VWF levels predict poor outcome in rodenticide-induced hepatotoxicity. VWF reduction may be useful in such patients.

A Mechanistic Model to Quantify von Willebrand Factor Release, Survival and Proteolysis in Patients with von Willebrand Disease.

A reduced von Willebrand factor (VWF) synthesis or survival, or its increased proteolysis, alone or in combination, contributes to the development of von Willebrand disease (VWD).We describe a new, simple mechanistic model for exploring how VWF behaves in well-defined forms of VWD after its 1-desamino-8-D-arginine vasopressin (DDAVP)-induced release from endothelial cells. We aimed to ascertain whether the model can consistently predict VWF kinetic changes. The study involved 9 patients with VWD types Vicenza (a paradigmatic form with a reduced VWF survival), 8 type 2B, 2 type 2A-I, 1 type 2A-II (associated with an increased VWF proteolysis), and 42 normal controls, whose VWF levels were measured after a 24-hour-long DDAVP test. The rate constants considered were: k0, associated with the VWF release phase; k1, illustrating the phase of conversion from high- to low-molecular-weight VWF multimers; and ke, associated with the VWF elimination phase. The amount of VWF released (D) was also measured. ke and D were significantly higher in O than in non-O blood group controls; k1 was also higher, but less markedly so. All the parameters were accelerated in type Vicenza, especially ke (p < 0.0001), which explains the significant reduction in VWF half-life. In types 2B and 2A-II, k1 was one order of magnitude higher than in controls, which explains their loss of large VWF multimers. All parameters except ke were lower in type 2A-I.The proposed mechanistic model clearly describes the altered biochemical pathways in well-characterized VWD, prompting us to suggest that it might help clarify elusive forms of VWD too.

Survival of HeartMate II Patients Despite Cessation of Anticoagulation　- Outcomes and Hemostatic Analysis.

BACKGROUND: In long-term left ventricular assist device (LVAD) therapy, recurrent bleeding events may justify cessation of anticoagulation therapy (AT). However, data about THE safety and risks of AT cessation in LVAD patients are scarce.Methods and Results:Between 2010 and 2015, 128 patients received a HeartMate II (HMII). Following recurrent bleeding events, we ceased vitamin K antagonist (VKA) therapy in 13 patients (10%) (no-VKA group). To characterize the hemostatic profile, we performed von Willebrand factor (vWF), platelet function (PF), and other hemostatic tests in all HMII patients. The incidence of pump thrombosis (PT), ischemic stroke (IS) and bleeding events in this HMII population was 4.7 %, 6.2% and 36.7%, respectively. Median survival without VKA was 435 days. No cases of PT and only 1 of IS occurred after AT discontinuation. All patients had impaired PF and acquired von Willebrand syndrome (AvWS). However, the vWF collagen-binding activity to antigen ratio before and after VKA cessation was significantly lower in the no-VKA group compared with the HMII population (0.60±0.12 vs. 0.73±0.14, P=0.006). The thrombin-antithrombin III complex (TAT) value was significantly higher in the no-VKA group (P=0.0005). CONCLUSIONS: We experienced good results with AT cessation in specific HMII patients. The simultaneous onset of AvWS and high TAT values could explain at least in part the low thromboembolic rate in HMII patients without VKA.

A case of autoimmune severe acquired von Willebrand syndrome (type 3-like).

Von Willebrand disease (VWD) is the most common congenital bleeding disorder and is due to quantitative or qualitative defects of von Willebrand factor (VWF). Acquired defects of VWF, termed acquired von Willebrand syndrome (AVWS), are due to a host of different mechanisms. Autoantibody-mediated AVWS may be associated with lymphoproliferative or immunological disorders, such as systemic lupus erythematosus (SLE). A large majority of AVWS cases are type 1 or type 2A-like and patients tend to have a mild to moderate bleeding tendency. We report a case of severe autoimmune AVWS in a woman with SLE who presented with clinical and laboratory features of type 3 VWD (undetectable VWF antigen, ristocetin cofactor activity, and VWF multimers). A mixing study demonstrated an inhibitor to VWF (6BU/mL). Her bleeds were managed with antifibrinolytics, recombinant activated factor VII, and activated prothrombin complex concentrate. She was initially treated with steroids and intravenous immunoglobulin therapy. However, her bleeding symptoms continued until she was treated with rituximab, and her VWF parameters normalized. She relapsed two years later due to non-compliance with her immunosuppressive medications and expired another two years later secondary to complications of sepsis and uremic pericarditis. This case emphasizes the importance of aggressive initial therapy of SLE to reduce secondary complications, frequent patient monitoring, and continued treatment of the underlying autoimmune disorder in patients with AVWS.

Contemporary issues in the management of von Willebrand disease.

Von Willebrand disease (VWD) is the most common inherited bleeding disorder. Bleeding scores in VWD, focused in particular on mucosal bleeding, can be very useful in the diagnosis and validation of different types of treatment. The results of an extended prospective study with a large amount of information on clinical phenotype and implications in treatment are reviewed in this article. Treatment of mucosal and joint bleeding in severe VWD remains difficult in some patients. Due to the lack of data on the use of prophylaxis in these patients it is difficult to establish optimal treatment regimens. An overview of the literature, with a focus on the ongoing PRO.WILL study, is provided here. Furthermore, understanding the changes in von Willebrand factor (VWF) levels during pregnancy is very important for establishing the optimal management strategy for pregnancy and delivery in women with VWD. A recently published prospective observational cohort study in women with and without VWD during the postpartum period provides important data that should allow the improvement of postpartum treatment protocols.

Cancers in Patients with von Willebrand Disease: A Survey from the Italian Association of Haemophilia Centres.

Besides its essential role in hemostasis, there is growing evidence that von Willebrand factor (VWF) has an additional antitumor effect. To elucidate the clinical significance of this biological activity we conducted a retrospective study on cancers among Italian patients with von Willebrand disease (VWD) on behalf of the Italian Association of Haemophilia Centres (AICE). A questionnaire to collect demographic, clinical, and treatment data of VWD patients with cancer was sent to all the 54 Italian Haemophilia Treatment Centres (HTCs) members of AICE. Overall, 18 HTCs (33%) provided information on 92 VWD patients (61 alive and 31 deceased) with 106 cancers collected during the period 1981 to 2014. Of them, 19 (18%) were hematological cancers and 87 (82%) were solid cancers. A total of 61% of patients had type 1, 36% type 2 (12% type 2A, 14% type 2B, 9% type 2M, and 1% type 2N), and 3% type 3 VWD: this distribution was significantly different from that observed in the whole VWD population (79% type 1, 16% type 2 [8% type 2A, 4% type 2B, 2% type 2M, 2% type 2N], and 5% type 3; type 2 vs. non-type 2: p < 0.001). Overall, VWD patients with cancer underwent 52 invasive and 72 surgical procedures, were treated with VWF/factor VIII (FVIII) concentrates in 77 cases, with desmopressin (DDAVP) alone in 24 cases and with DDAVP and VWF/FVIII concentrates in 7 cases. Hemorrhagic complications were observed only rarely (2% of invasive procedures and radiotherapy and 6% of surgical interventions). The data collected by this survey document that a substantial number of cancers are recorded among VWD patients and that these patients are safely managed by HTC physicians through a multidisciplinary approach.

The bleeding score predicts clinical outcomes and replacement therapy in adults with von Willebrand disease.

Analyses of the bleeding tendency by means of the bleeding score (BS) have been proposed until now to confirm diagnosis but not to predict clinical outcomes in patients with inherited von Willebrand disease (VWD). We prospectively followed up, for 1 year, 796 Italian patients with different types of VWD to determine whether the previous BS of European VWD1 is useful to predict the occurrence of spontaneous bleeds severe enough to require replacement therapy with desmopressin (DDAVP) and/or von Willebrand factor (VWF)/factor VIII concentrates. Among the 796 patients included, 75 (9.4%) needed treatment of 232 spontaneous bleeding events. BS >10 and VWF:ristocetin cofactor activity <10 U/dL were associated with the risk of bleeding, but only a BS >10 remained highly associated in a multivariable Cox proportional hazard model (adjusted hazard ratio: 7.27 [95% confidence interval, 3.83-13.83]). Although the bleeding event-free survival was different in VWD types, only a BS >10 could predict for each type which patient had bleeding events severe enough to require treatment with DDAVP and/or concentrates. Therefore, BS can be considered a simple predictor of clinical outcomes of VWD and may identify patients needing intensive therapeutic regimens.

[New data from the German Haemophilia Registry]. / Neue Daten aus dem Deutschen Hämophilieregister.

UNLABELLED: The German Haemophilia Registry records online data from patients with haemophilia A, haemophilia B, von Willebrand`s disease and other coagulation factor deficiency disorders since 2009. Patient's pseudonymised data will only be enrolled in the German Haemophilia Registry if the patient signs an informed consent. Without the informed consent, only aggregated data according to §21 German Transfusion Law are reported. These data include the number of persons with congenital haemostasis disorders classified to type of disease and severity as well as patients' age, and the consumption of clotting factor according to each group. RESULTS: The highest number of patients with haemophilia was reported in 2010: 3375 patients with haemophilia A and 614 with haemophilia B respectively; the highest number of patients with von Willebrand's disease was 1473, reported in 2011. CONCLUSION: In comparison to data from registries in Austria and Switzerland it can be assumed that most of the patients with severe haemophilia are registered in the German Haemophilia Registry whereas patients with moderate and mild forms are still missing.

Haemophilia Registry of the Medical Committee of the Swiss Haemophilia Society. Update and annual survey 2011/12.

The Haemophilia Registry of the Swiss Haemophilia Society is currently more than 12 years old. We present here the data as from October 31st, 2012. Registered are patients with haemophilia A and B, von Willebrand disease with VWF:R-Co < 10% and other rare factor deficiencies. For this latter group, inclusion in the Registry depends on the clinical relevance of the bleeding disorder, not on the factor level. Data come directly from the Swiss haemophilia reference and treatment centers and should be updated once a year. Currently 967 patients are registered, the majority (587) presenting with haemophilia A. Disease severity is graded according to ISTH criteria. Basic epidemiological findings are similar to those from larger registries in Europe, Canada or the USA. More that 60% of persons with haemophilia in Switzerland are treated on-demand, with the exception of young patients (<20 years) who present an 80 to 90% rate of prophylactic therapy. Nevertheless, global use of factor concentrates went continuously up over the last decade and reaches now 5.52 Units per capita, still a low value compared to other high-income European countries. A recent survey of the Registry shows that treaters' compliance with yearly data updates is insufficient; measures will be undertaken in 2013 to enhance data quality.

Morbidity and mortality of haemophilia patients in Germany. Survey results 2011/2012.

Since 1982, the multicenter study of the epidemiology of patients with haemophilia is carried out annually with the support of all sizes of haemophilia centers and treatment facilities. The long period of investigation has not only enabled the reporting of up-to-date mortality and morbidity status, but also of retrospective observations. The participating centers have made anonymized data available for patients with Haemophilia A, B and von Willebrand's disease (total counts for treated patients, type and severity of the disease, HIV status and causes of death). For 2011-2012 3331 patients were reported with haemophilia A or B from 32 centers. Although the mortality from HIV/AIDS in haemophilia patients continues to decline, HIV infection remains clinically relevant since an HIV/HCV coinfection can raise the risk of severe liver disease. The data from the multicenter survey were, together with the anonymized data from the Foundation for Humanitarian Aid for Persons Infected with HIV though Blood Products, comparatively descriptively compared and the temporal progression illustrated by a so-called moving average. Expectedly, haemophilia patients were shown to be under-represented by the data from the multicenter survey. Otherwise, the data are consistent.

[Morbidity and mortality of patients with haemophilia in Germany--update 2010/2011]. / Morbidität und Mortalität der Hämophilie-Patienten in Deutschland. Update 2010/2011.

Since 1982 an annual multicentric survey regarding the epidemiology of patients suffering of haemophilia is performed with support of haemophilia treating centres of any size. Again, the actual compilation is resting upon a broad database returning to over 30 years of inquiry well representing both the actual and retrospective status of mortality. Prompted was exclusively information about patients with haemophilia A, B and von Willebrand disease. In particular anonymous data concerning the preceeding 12 months about number of treated patients, type and severity of illness, HIV-status and detailed information about causes of death was inquired. This data was merged with existing data and analysed statistically. In the 2009/2010 survey, a total number of 9448 patients with bleeding disorders have been reported from 47 participating centres. Despite mortality from HIV in patients with haemophilia is keeping on decreasing, HIV still remains an important factor as an HIV/HCV coinfection seems to increase risk of progression of severe liver disease. In the actual investigation the findings of the foundation "Humanitäre Hilfe für durch Blutprodukte HIV-infizierte Personen" were compared for the first time to our data. Time trends were visualised with a moving average. Our investigation has a smaller number of deceased patients, but contains consistent data.

Haemophilia registry of the Medical Committee of the Swiss Hemophilia Society. Update and annual survey 2010-2011.

The Haemophilia Registry of the Swiss Haemophilia Society was created in the year 2000. The latest records from October 31st 2011 are presented here. Included are all patients with haemophilia A or B and other inherited coagulation disorders (including VWD patients with R-Co activity below 10%) known and followed by the 11 paediatric and 12 adult haemophilia treatment or reference centers. Currently there are 950 patients registered, the majority of which (585) having haemophilia A. Disease severity is graded according to ISTH criteria and its distribution between mild, moderate and severe haemophilia is similar to data from other European and American registries. The majority (about two thirds) of Swiss patients with haemophilia A or B are treated on-demand, with only about 20% of patients being on prophylaxis. The figure is different in paediatrics and young adults (1st and 2nd decades), where 80 to 90% of patients with haemophilia A are under regular prophylaxis. Interestingly enough, use of factor concentrates, although readily available, is rather low in Switzerland, especially when taking the country's GDP into account: The total amount of factor VIII and IX was 4.94 U pro capita, comparable to other European countries with distinctly lower incomes (Poland, Slovakia, Hungary). This finding is mainly due to the afore mentioned low rate of prophylactic treatment of haemophilia in our country. Our registry remains an important instrument of quality control of haemophilia therapy in Switzerland.

[Haemophilia patients in Germany 2008/2009. Morbidity and mortality]. / Hämophilie-Patienten in Deutschland 2008/2009. Morbidität und Mortalität.

Since 1978 an annual multicentric survey regarding the epidemiology of patients suffering of haemophilia is performed with support of hemophilia treating centres of any size. Again the actual compilation is resting upon a broad database returning to over 30 years of inquiry well representing both the actual and retrospective status of mortality. Prompted was exclusively information about patients with haemophilia A, B and von Willebrand disease. In particular anonymous data concerning the last 12 months about number of treated patients, type and severity of illness, HIV-status and detailed information about causes of death was inquired. This data was merged with existing data and analyzed statistically. In the 2008/2009 survey, a total number of 9101 patients with bleeding disorders have been reported from 66 participating centres. Despite mortality from HIV in patients with haemophilia is keeping on decreasing, HIV still remains an important factor as an HIV/HCV coinfection seems to increase risk of progression of severe liver disease. Age structure in our patients has been shifting significantly over the last decades bringing age distribution into line with the entire population. This has to be considered assessing mortality and morbidity.

[Morbidity and mortality of patients with haemophilia in Germany 2007/2008]. / Morbidität und Mortalität von Hämophilie-Patienten in Deutschland 2007/2008.

Since 1978 an annual multicentric survey regarding the epidemiology of patients suffering of haemophilia is performed with support of haemophilia treating centres of any size. Again the actual compilation is resting upon a broad database returning to over 30 years of inquiry well representing both the actual and retrospective status of mortality. Prompted was exclusively information about patients with haemophilia A, B and von Willebrand disease. In particular anonymous data concerning the last 12 months about number of treated patients, type and severity of illness, HIV-status and detailed information about causes of death was inquired. This data was merged with existing data and analyzed statistically. In the 2007/2008 survey, a total number of 8904 patients with bleeding disorders have been reported from 63 participating centres. Despite mortality from HIV in patients with haemophilia is keeping on decreasing, HIV still remains an important factor as an HIV/HCV coinfection seems to increase risk of progression of severe liver disease. Age structure in our patients has been shifting significantly over the last decades bringing age distribution into line with the entire population. This has to be considered assessing mortality and morbidity.

[Causes of death in patients with haemophilia in Germany 2006/2007]. / Todesursachen bei Hämophilie-Patienten in Deutschland 2006/2007.

Since 1983 (survey period returning to 1978) with support of numerous haemophilia treating centres of any size an annual survey regarding the epidemiology of patients suffering of haemophilia is performed. The actual compilation is resting upon a broad database returning to almost 30 years of inquiry well representing both the actual and retrospective status of mortality. Prompted was exclusively information about patients with haemophilia A, B and von Willebrand disease. In particular anonymous data concerning the last 12 months about number of treated patients, type and severity of illness, HIV-status and detailed information about causes of death was inquired. This data was merged with existing data and analyzed statistically. In the 2006/2007 survey, a total number of 8188 patients with bleeding disorders have been reported from 69 participating centres. Despite mortality from HIV in patients with haemophilia is decreasing, HIV still remains an important factor as a HIV/HCV coinfection seems to increase risk of progression of liver disease. Age structure in our patients has been shifting significantly over the last decades bringing age distribution into line with the entire population. This has to be considered in assessing mortality and morbidity.

Identification of type 1 von Willebrand disease patients with reduced von Willebrand factor survival by assay of the VWF propeptide in the European study: molecular and clinical markers for the diagnosis and management of type 1 VWD (MCMDM-1VWD).

The decreased survival of von Willebrand factor (VWF) in plasma has been implicated as a mechanism in a subset of type 1 von Willebrand disease (VWD) patients. We have previously reported that the ratio of plasma levels of VWF and its propeptide (VWFpp) can be used to identify patients with reduced VWF survival. In this study, we report the assay of VWFpp and VWF:Ag in 19 individuals recruited from 6 European centers within the MCMDM-1VWD study. Eight individuals had a VWF:Ag level less than 30 IU/dL. Seven of these patients had a robust desmopressin response and significantly reduced VWF half-life that was predicted by a markedly increased steady-state plasma VWFpp/VWF:Ag ratio. VWF mutations previously associated with reduced VWF survival were identified in each of the 7 individuals. Thus, a substantially increased ratio of steady-state VWFpp/VWF:Ag predicted a reduced VWF half-life in patients with markedly decreased VWF:Ag levels. These data indicate that a reduced VWF survival is found in a subpopulation of patients with type 1 VWD. The systematic assay of both plasma VWF and the VWF propeptide in moderately severe type 1 VWD patients may identify patients with a reduced VWF survival phenotype.