Photo credit: www.sciencedaily.com
A recent study published in Blood highlights a concerning trend: the incidence of stroke is on the rise among both adults and children with sickle cell disease (SCD), despite established care standards set by the Stroke Prevention Trial in Sickle Cell Anemia (STOP). This study emphasizes the need for continuous monitoring and effective intervention strategies for patients at high risk.
Sickle cell disease, the most prevalent inherited red blood cell disorder in the United States, makes individuals particularly vulnerable to cerebrovascular events (CVEs). These events encompass ischemic or hemorrhagic strokes, which occur due to blocked or burst blood vessels leading to the brain, and transient ischemic attacks (TIAs), characterized by temporary blood flow blockage without lasting damage.
The STOP trial, a pivotal study published in 1998, provided evidence that regular red blood cell transfusions could significantly reduce the occurrence of CVEs in high-risk children, as identified through abnormal blood flow evaluated via Transcranial Doppler (TCD) testing.
In an extensive population-based analysis led by Dr. Wun and his team, findings indicate that the risk of stroke escalates with age, doubling for every two decades. “Traditionally, our training as hematologists has led us to regard young children as the highest risk group for strokes,” remarked Dr. Ted Wun, the study’s senior author and associate dean for clinical and translational research at the University of California Davis School of Medicine. “Unfortunately, this focus has overshadowed the need to understand stroke risks in adult patients, where data is notably sparse.” The study suggests that applying child-centric TCD guidelines to adults lacks empirical support and might require re-evaluation.
Utilizing data from California’s Emergency Department Utilization and Patient Discharge Data from 1991 to 2019, researchers identified 7,636 SCD patients, of which 733 (about 9.6%) had at least one recorded CVE. The breakdown includes 451 (5.9%) ischemic strokes, 227 (3%) hemorrhagic strokes, and 205 (2.7%) TIAs. Notably, women and those with frequent hospitalizations—three or more admissions per year—exhibited a higher prevalence of CVEs.
The study also observed a dramatic 13-fold increase in the cumulative incidence of hemorrhagic stroke between ages 20 and 60. Alarmingly, despite an initial decline in CVEs following the release of STOP guidelines, the highest rates of these events were recorded in the last decade (2010-2019) across all ages.
Dr. Wun commented, “The trends we see, even among children who receive what is presumed to be optimal care for SCD in the U.S., paint a troubling picture. This suggests that the STOP guidelines are not being implemented effectively.” The researchers propose several factors contributing to the increase in stroke cases post-STOP. These include reduced adherence to TCD screening recommendations, advancements in diagnostic technologies for ischemic strokes, inadequate blood transfusion rates, and low utilization of hydroxyurea—a medication aimed at preventing sickling of red blood cells. The analysis also identified modifiable stroke risk factors such as frequent hospitalizations, hypertension, high cholesterol, and prior TIAs, revealing that individuals with acute chest syndrome, liver failure, and prior ischemic strokes are particularly susceptible to hemorrhagic strokes.
Dr. Olubusola Oluwole, the study’s first author and assistant professor at the University of Pittsburgh, emphasizes that this new data reinforces the necessity of monitoring chronic health issues such as high cholesterol and hypertension in adults with SCD. “Preventive measures that are efficacious in the general populace for stroke prevention are equally relevant for individuals with SCD,” he noted, especially as advancements in care continue to extend the lifespan of patients.
The study, however, does carry certain limitations, including gaps in reliable data regarding tobacco usage, which is known to elevate stroke risk, as well as variances in SCD genotypes among participants. The authors also lacked access to specific imaging reports to definitively confirm stroke diagnoses. Furthermore, the true prevalence of CVEs in California’s SCD population may be underestimated, particularly if patients experienced strokes outside the state, succumbed to strokes before hospitalization, or managed TIA symptoms without seeking medical attention.
In conclusion, the authors advocate for further interventional and prospective research efforts focused on understanding and addressing stroke risks in adults with sickle cell disease.
Source
www.sciencedaily.com