Researchers have found that the incidence of hemorrhagic stroke in patients with sickle cell disease (SCD) increases with age, according to a study published in Stroke. 

Patients with SCD are at a higher risk of developing both hemorrhagic and ischemic stroke. While the prevention of ischemic stroke in this group of patients has garnered attention in the research world, the same cannot be said about hemorrhagic stroke, which remains poorly characterized.

To understand the prevalence of hemorrhagic stroke in patients with SCD, the authors of the study retrospectively recruited patients who participated in the Stroke Prevention Trial in Sickle Cell Anemia (STOP) and the Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP II) trials. The trials were conducted from 1995 to 2005. 

The STOP and STOP II trials recruited children with SCD type SS or S-beta-thalassemia between 2 and 16 years of age; patients with a previous history of stroke were excluded. The research team was able to gain the participation of 19 of the 26 United States/Canadian sites that participated in those studies. 

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“Between January 2012 and May 2014, a team of analysts visited each site and conducted a structured data abstraction from all available medical records after the original STOP or STOP II trials ended,” the authors wrote. “When the team identified any potential neurological event, they collected additional data including imaging reports and outpatient neurology records.”

The research team managed to study 3539 patients, constituting 92.3% of the total participants in the original trials. Follow-up data were available for 2851 of the 3539 patients. They discovered that the overall incidence rate of hemorrhagic stroke was 63 per 100,000 person-years; this, however, varies with age. In children up to 18 years of age, the incidence rate was 50.4 per 100,000 person-years; in adults over 18 years of age, the incidence rate was 134 per 100,000 person-years. 

“We found that [hemorrhagic stroke] incidence rates increase with age in young patients with [sickle cell anemia],” the authors wrote. “More research is needed to examine health care utilization of [hemorrhagic stroke] and develop [hemorrhagic stroke] prevention strategies like those successful in primary prevention of ischemic stroke.” 


Fox CK, Leykina L, Hills NK, et al. Hemorrhagic stroke in children and adults with sickle cell anemia: the post-STOP cohortStroke. 2022;101161STROKEAHA122038651. doi:10.1161/STROKEAHA.122.038651