Safety and efficacy of anti‐coagulation for primary and secondary venous thromboembolism prophylaxis in hospitalized adolescents and young adults with sickle cell disease: An institutional experience

Venous thromboembolism (VTE) is a common cause of morbidity and mortality in sickle cell disease (SCD). The aim of the study was to review the safety and effectiveness of primary and secondary anti-coagulation prophylaxis in hospitalized SCD patient population and to identify potential VTE risk factors. Retrospective review of prescribed anti-coagulants in hospitalized SCD patients from 1 January 2015 to 11 July 2023. Pharmacological prophylaxis was provided to those ≥13 years of age. Bleeding and thrombosis outcomes were classified as per the International Society Thrombosis and Haemostasis. Generalized logistic mixed models with a random intercept for each patient were used to assess VTE risk. Seven hundred and ninety hospital encounters among 140 unique patients were reviewed. Median age at admission: 17.2 years (interquartile range [IQR]: 13.9-19.0). Primary and secondary prophylactic anti-coagulation was prescribed in 81.0% (n = 640) and 18.4% (n = 146) hospital encounters respectively. Thirty VTE events were identified among 22 individuals (3.8%; n = 30/790). Seven VTE recurrences/progression (23.3%) occurred. Surgical splenectomy was significantly associated with VTE (53.3%; n = 16/30) versus those without VTE (23.3%; n = 177/760) (odds ratio 4.23, 95% confidence interval [CI] 1.36-13.15; p = 0.0128). Despite the use of pharmacological VTE prophylaxis, 30 VTE events with a thrombosis recurrence/progression rate of 23.3% occurred. Further studies are needed to guide pharmacological prophylaxis for those at greater thrombosis risk.