Prevalence and Risk Factors for Venous Thromboembolism in People With Inherited Bleeding Disorders: An <scp>ATHNdataset</scp> Study

It is presumed that people with inherited bleeding disorders are protected against the risk of venous thromboembolism (VTE) but the supporting data regarding rates and risk factors for VTE in this population are lacking. The objectives of this study were to determine the VTE rates and risk factors in a cohort of individuals with inherited bleeding disorders. American Thrombosis and Hemostasis Network (ATHN) dataset was utilized for this study. The population of interest was individuals with an inherited bleeding disorder with a documented VTE. Data were collected regarding their bleeding disorder, demographics, type of VTE, and comorbidities. Data were summarized using standard descriptive analyses, and logistic regression analyses were used to identify risk factors. We identified a total of 49,151 individuals with inherited bleeding disorders in the ATHNdataset. A total of 388 new VTE (0.8%; 95% CI: 0.7, 0.9) were observed. Median age at VTE diagnosis was 27.5 years (IQR: 15.3-48.2). VTE rates were highest in prothrombin deficiency at 19% and relatively lower in hemophilia A and B at 0.4%. Within the hemophilia cohort, rates of VTE were higher in those with inhibitors (p < 0.001). The VTE recurrence rate was 4.9% (n = 19/388). On multivariable analysis, Black race (OR = 1.90), central venous line (CVL) (OR = 2.76), and cardiac comorbidity (OR = 16.86) were identified as risk factors for VTE. In summary, our results demonstrate that people with inherited bleeding disorders are not protected against VTE. Individual factors such as cardiac comorbidity and the presence of a CVL can increase the prothrombotic risk.