What is the evidence for the effectiveness of blood transfusion in reducing recurrent clinical ischemic stroke and progression of arterial stenosis in patients with SCD?
The STOP trial was a randomized, placebo-controlled trial that showed that a long-term prophylactic transfusion strategy was effective for the primary prevention of stroke in children with SCD and high TCD velocities.655 Blood transfusion was used because it was demonstrated effective in reducing recurrent clinical ischemic stroke and progression of arterial stenosis in a series of children with SCD.656 This was associated with a reduction in the rate of recurrent stroke during a mean follow-up of 3 years compared with historical control subjects.657 Most of the patients in the series were children, and it is unclear whether adults have the same untreated risk or benefit from treatment.658 Regular transfusions are associated with long-term complications, especially iron overload, typically requiring iron chelation therapy. The SIT trial showed reduced recurrent stroke in children with SCD and silent cerebral infarct who underwent transfusion compared with