Nearly a quarter of patients with sickle cell disease (SCD) accompanied at the Boston Medical Center/Boston University School of Medicine in Massachusetts suffered from venous thromboembolism (VTE) within a 15-year period, as published in Thrombosis Update.

The cohort consisted of 233 patients with SCD (median age, 36 years, age range, 23-77, 53% female). Of those, 55 had at least 1 VTE event. The total amount of VTE events was 94; 24 patients had a pulmonary embolism (PE), 19 had a deep venous thrombosis (DVT) in the lower or upper extremities with 13 being catheter-associated upper extremity DVTs, and 13 had both DVT and PE.

Most (85%) of the patients who had a VTE experienced their first episode before the age of 40. The youngest case referred to a 14-year old individual and 2 additional pediatric cases were reported (15 and 17 years old).

“There appears to be increased VTE risk associated with known VTE risk factors such as higher [body mass index] and prior splenectomy and possibly SCD-specific risk factors such as leukocytosis which may indicate a sub-group of the population for whom greater clinical vigilance is warranted,” the authors said.

Read more about SCD risk factors

Markers of SCD severity, such as hemoglobin genotype and concentration and markers of hemolysis, were not associated with increased VTE risk. Patients with SCD with a VTE had a higher frequency of prior stroke and avascular necrosis, as well as increased rates of emergency department visits and hospital admissions than those without a VTE.

Most (93%) patients with VTE were treated with anticoagulation therapeutics, starting with either low molecular weight or unfractionated heparin. Outpatient treatment for the first event included warfarin (56%), enoxaparin (16%), rivaroxaban (9%), apixaban (6%), fondaparinux (4%), and dalteparin (2%).

Cell Transplantations May Reduce Thrombotic Events in SCD

A total of 39 recurrent VTEs were observed in 24 patients, with 13 occurring during anticoagulation therapy (rivaroxaban [26.7%], warfarin [18.9%], and low molecular weight heparin [10%]). Two patients on warfarin therapy had intracranial hemorrhages. Patients with recurrent VTEs were also at high risk for subsequent thromboses.

“These data may support the need for lifelong anti-coagulation for a non-provoked first time VTE in this population and the need for a greater understanding of how thrombosis contributes to the pathophysiology of SCD,” the authors concluded.


Scarpato B, Strykowski R, Lawrence R, et al. Risk factors for venous thromboembolism and clinical outcomes in adults with sickle cell disease. Thromb Updat. Published online February 18, 2022. doi:10.1016/j.tru.2022.100101