Cardiovascular disease-related hospitalization and mortality among persons with von Willebrand disease: A nationwide register study in Sweden.

INTRODUCTION: It has been hypothesized that persons with von Willebrand disease (VWD) may be protected against arterial thrombosis despite having atherosclerosis. AIM: To calculate a nationwide estimate of the absolute and comparative burden of cardiovascular disease (CVD) hospitalization and mortality among persons with VWD using birthdate and sex-matched comparisons from the general population in Sweden. METHODS: Persons with VWD regardless of the type and severity, diagnosed by a medical doctor, who lived in Sweden for some time during the observation period 1987 through 2008 were included. For each participant with VWD, up to five randomly selected birthdate- and sex-matched persons from general population were selected as controls. RESULTS: A total of 2790 participants with VWD including 888 male and 1902 female subjects and 13 938 controls were included. Overall, the hazard of CVD-related hospitalization was 1.3-fold (95% CI: 1.1, 1.5) among participants with VWD after adjusting for sex, birthdate, diabetes and cancer. However, they had a 0.4-fold (95% CI: 0.3, 0.6) hazard of CVD-related mortality compared to general population sample. CONCLUSIONS: In this nationwide, long-term register study with individually matched controls, we have been able to show that persons with VWD have a higher hospitalization rate due to CVD events. However, the mortality rates appear lower than in the control population. The latter finding is consistent with previous studies and indicates a protective effect of the clotting factor deficiency inherited with VWD.

Patients Referred for Bleeding Symptoms of Unknown Cause: Does Evaluation of Thrombin Generation Contribute to Diagnosis?

INTRODUCTION: Patients with mild to moderate bleeding symptoms referred for coagulation investigation sometimes never receive a definitive diagnosis. Bleed assessment tools have been developed and validated to assess the severity of symptoms. Global coagulation assays, e.g., the thrombin generation test (thrombogram) have a potential to identify hemostatic defects that are not detected in specific assays. MATERIAL AND METHODS: One hundred and eighty-five patients referred to our centre because of bleeding symptoms were evaluated using the bleeding assessment tool (BAT) described by Tosetto and colleagues in 2006. Blood samples were investigated for thrombin generation (TG) capacity (Technoclone), in platelet poor (PPP) plasma, and specific clotting factors, i.e., von Willebrand factor, factor VIII and IX, as well as INR, APTT, platelet count, and platelet adhesion. RESULTS: Of the 185 patients, five women were diagnosed with mild von Willebrand disease and one male with mild hemophilia A. The remaining 179 subjects (76% females and 24% males with average ages of 33 and 28 years, respectively) were evaluated further. In the total cohort and among women, peak TG, and lag time correlated with bleeding score (p=0.01 and p=0.04, respectively with correlation coefficients). No such correlations were found among males. DISCUSSION AND CONCLUSION: Although our study showed some correlation between TG and bleeding score, results are generally consistent with a previous report which failed to demonstrate the value of TG measurement in a similar setting. In conclusion, the complexity of the mechanisms underlying clinical bleeding complicates the ability to use TG tests as reliable predictors of bleeding. Mild congenital bleeding disorders, especially VWD, should be specifically screened for in patients with mild/moderate symptoms.

Changes in bleeding patterns in von Willebrand disease after institution of long-term replacement therapy: results from the von Willebrand Disease Prophylaxis Network.

Clinically, the leading symptom in von Willebrand disease (VWD) is bleeding, chiefly of mucosal type, for example, epistaxis, gingival, or gastrointestinal bleeding, and menorrhagia. In severe forms of VWD with secondary deficiency of factor VIII, spontaneous joint bleeding, resembling that observed in severe haemophilia A, may also be observed. The bleeding patterns of VWD can affect quality of life, and may be life-threatening. The von Willebrand Disease Prophylaxis Network is an international study group formed with the goal of investigating the role of prophylaxis in clinically severe VWD. The objective of the present study is to investigate the response to prophylaxis focusing primarily on epistaxis, joint bleeding, gastrointestinal bleeding, and heavy bleeding associated with menses. Data from 105 subjects, 10 enrolled in a prospective study and 95 in a retrospective study between 2008 and 2013, were available for analysis. The median annualized rate reductions in bleeding were significant for epistaxis (P < 0.0001), gastrointestinal bleeding (P = 0.0003), joint bleeding (P < 0.0001), and menorrhagia (P = 0.008). Doses on a group level were approximately the same prior to and during prophylaxis, but more patients with gastrointestinal bleeding had prophylaxis three or more times per week as well as higher dosages. Our study, which primarily used retrospective data, indicates that prospective studies are needed to better delineate the doses and dose intervals that should be used for prophylactic treatment of VWD.