Adults with SCD face high risk of stroke in their 30s and 40s, study finds
'Significant gaps' found in stroke management, leading to lasting disability
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Adults with sickle cell disease (SCD) face a substantial risk of stroke, most often in their 30s and 40s, with lasting physical disability and cognitive impairment, a new study reports.
Also, despite recommendations, few patients received blood transfusions shortly after stroke, underscoring “significant gaps in acute stroke management,” the researchers wrote.
Key among the study’s findings, according to the team, was a lack of preventive care during childhood for people with SCD.
“The elevated stroke burden sheds light on missed opportunities for early identification and paediatric intervention,” the team wrote, noting that fewer than one-quarter of adult stroke patients had been followed in pediatric care centers. Moreover, “two individuals were diagnosed with SCD only after presenting with stroke in adulthood,” the researchers noted.
Strokes due to blocked blood flow occurred when people with SCD had a median age in their 30s, while strokes caused by brain bleeding were more likely to occur among individuals at a median age in their mid-40s, the data showed.
Taken together, these findings emphasize the need “to improve stroke prevention strategies, optimizing acute interventions and ultimately reducing long-term disability in adults living with SCD,” the researchers wrote.
The study, “Stroke burden and functional impacts in adults with sickle cell disease,” was published in the British Journal of Haematology by researchers in Canada.
An inherited blood disorder, SCD is caused by mutations in the HBB gene that lead to the production of abnormal hemoglobin, the protein that carries oxygen in red blood cells. As a result, these cells become rigid and sickle-shaped, are destroyed prematurely, and block small blood vessels.
People with SCD remain at higher risk of stroke throughout their lives
Studies have shown that people with SCD are at a higher risk of stroke. This is in part because blood vessel blockage in the brain may prevent certain regions from receiving enough oxygen and nutrients, causing damage.
“Stroke in sickle cell disease (SCD) has been well characterized in children, but data in adults remain insufficient, particularly regarding long-term functional consequences,” the researchers wrote.
To fill this knowledge gap, a team of Canadian researchers retrospectively analyzed data from 454 adults with SCD who were followed at the Montreal University Hospital Center. The patients’ median age was 32, and slightly more than half were women.
A higher proportion (48%) had the HbSS genotype, the most common and often the most severe form of SCD, while 42% had the HbSC genotype, which is typically less severe.
Overall, 21 participants — about 5% of the study population — experienced at least one symptomatic stroke at some point in their lives.
The most common event was ischemic stroke, occurring in about two-thirds of cases and caused by blocked blood flow. These strokes occurred in patients at a median age of 32 (range 4-68 years). Hemorrhagic stroke, which is caused by bleeding in the brain, occurred in the remaining one-third of cases. Individuals experienced these strokes at a median age of 45 (range 20-65 years).
Those experiencing ischemic stroke were more commonly aged between 21 and 30 (29%) or 51 older (29%). This was followed by individuals as old as age 10 (14%).
Hemorrhagic stroke, meanwhile, was more common in patients older than 41 (71%).
Few transfusions given ‘despite established recommendations’
The lasting effects of stroke on patients’ cognitive function and physical disability were assessed using the Montreal Cognitive Assessment (MoCA) and the Modified Rankin Scale (mRS), two standard tools used in stroke care.
After a stroke, patients had significantly lower median cognitive MoCA scores compared with those who had never had a stroke (20.6 vs. 26.1). A score of 25 or lower, which indicates mild cognitive impairment, was reported in more than half (57%) of individuals with stroke.
Participants who experienced a stroke also had significantly higher median mRS scores, indicating more physical disability, than those without stroke (2 vs. zero).
These group differences remained statistically significant after adjusting for patients’ age and sex, as well as high blood pressure, the data showed.
Acute stroke management, within 24 hours of the event, included simple or exchange blood transfusions in six patients. Simple transfusions involve administering healthy red blood cells to the patient’s bloodstream, while exchange transfusions replace the patient’s red blood cells with healthy red blood cells collected from donors.
No participant received acute reperfusion therapy, which aims to restore blood flow after ischemic stroke. This usually was because the patients arrived at a hospital too late after a stroke to receive such treatments; these therapies are usually applied within 4.5 hours after stroke, according to the researchers.
These “findings underscore significant gaps in acute stroke management,” the researchers wrote. “Despite established recommendations, very few patients received acute simple or exchange transfusion at symptom onset.”
Improved [stroke] prevention and acute management strategies are urgently needed for adults with sickle cell disease.
In the case of brain bleeding, damaged blood vessels were more commonly repaired via minimally invasive approaches where thin tubes are inserted in blood vessels, followed by open brain surgery, the data showed.
Chronic treatments after stroke involved a combination of hydroxyurea (a common SCD therapy sold in the U.S. as Siklos and Xromi) and blood transfusions, blood transfusions alone, or hydroxyurea alone. A total of 10 patients also received antiplatelet therapy, while five were given oral anticoagulants; both to prevent blood clot formation.
After the first stroke, two patients (10%) died, and five (24%) experienced stroke recurrence despite regular blood transfusions, per the researchers.
Overall, this study shows that “strokes occurred at a young median age and were associated with long-term functional impairment” in adults with SCD, the researchers wrote.
“Improved prevention and acute management strategies are urgently needed for adults with sickle cell disease,” the team noted.
