Thromboembolic Complications in Patients with Sickle Cell Disease

Background and Purpose: Venous thromboembolism (VTE) is common in patients with sickle cell disease (SCD). Traditional risk factors such as central venous catheters, frequent hospitalization, orthopedic surgeries for avascular necrosis, and pregnancy often leads to an increased incidence of VTE in the SCD. In addition, SCD itself appears to be a hypercoagulable state with many SCD-specific factors such as genotype, splenectomy and thrombophilia modifying the risk of VTE. This study aims to assess the clinical and pathological characteristics of VTE amongst a cohort of patients with SCD at the Sultan Qaboos University Hospital and determine its relation to morbidity and mortality.

Methodology: In this retrospective case control study, medical details of all patients with SCD who developed thromboembolic complications over the past decade were retrieved from the hospital information system. SCD patients matched for age and gender (2:1 ratio) who did not have thromboembolic complications but had a thrombophilia screen performed served as controls. The study was approved by the local Medical Research and Ethics Committee.

Results & Discussion: A total of 53 SCD patients were enrolled [34 cases, 19 controls] in this study. Amongst the 34 cases (mean age-30 yrs.), 18 had pulmonary embolism, eight had deep venous thrombosis, whereas, three each had cerebral venous thrombosis and portal venous thrombosis and one each had cerebral arterial thrombosis and VTE. A higher incidence of autosplenectomy(69.7% v/s 52.6%) and central venous catheters(42.4% v/s 5.3%) were significantly associated with thrombosis (p<0.05, Chi Square test). High LDH levels, WBC and Platelet counts were significant risk factors(p<0.05) for VTE. 21 patients [63.6%] amongst the cases developed acute chest syndrome, where 3[9%] had cerebrovascular accident. Mortality was seen in seven cases [21%].

Conclusions: The study shows that thromboembolic complications in SCD has a high impact on the morbidity and mortality. It confirms PE as the leading cause for VTE in SCD with asplenia, central venous catheter, high LDH, WBC and Platelet counts being significant risk factors.