Overview

A new study highlights a troubling trend: the rate of stroke among individuals with sickle cell disease (SCD) continues to rise, defying established medical guidelines aimed at preventing these potentially devastating events. This alarming finding was published in the journal Blood and points to a significant gap in care for both adults and children affected by this inherited blood disorder.

Understanding Sickle Cell Disease and Stroke Risks

Sickle cell disease, the most prevalent inherited red blood cell disorder in the United States, predisposes individuals to cerebrovascular events (CVEs), which encompass ischemic strokes (caused by blood clots), hemorrhagic strokes (resulting from burst blood vessels), and transient ischemic attacks (TIAs). These events can severely affect brain function and overall health.

The STOP Trials and Their Findings

The landmark Stroke Prevention Trial in Sickle Cell Anemia (STOP)—conducted in 1998—set forth crucial guidelines, including red blood cell transfusions and Transcranial Doppler (TCD) testing to monitor blood flow in high-risk patients. Unfortunately, despite these protocols, research led by Dr. Ted Wun of the University of California Davis School of Medicine indicates that the incidence of strokes has not diminished as intended.

Study Analysis and Findings

In a comprehensive study utilizing data from California’s Emergency Department Utilization and Patient Discharge Data systems, the team examined the health outcomes of 7,636 SCD patients. The findings revealed that 733 individuals (9.6%) had experienced a CVE, with ischemic strokes, hemorrhagic strokes, and TIAs occurring in 451 (5.9%), 227 (3%), and 205 (2.7%) individuals, respectively. Notably, the research indicated that women and individuals hospitalized frequently were at higher risk.

Increasing Hemorrhagic Stroke Risks

Alarmingly, the cumulative risk of hemorrhagic strokes surged 13-fold from ages 20 to 60. While a brief dip in CVEs followed the release of the STOP guidelines, subsequent years—specifically the decade from 2010 to 2019—showed an increase in CVEs across all age categories.

Neglect of Adult Patients

Dr. Wun noted that the prevailing belief in medical training—that stroke risk is predominantly a concern for younger children—has led to a neglect of adult patients’ needs. There remains a gap in understanding how pediatric stroke prevention measures relate to adults with SCD.

Possible Reasons for Rising Stroke Rates

Possible explanations for the increasing stroke rates post-STOP include diminished adherence to TCD monitoring, advances in diagnostic technology revealing more ischemic strokes, low rates of blood transfusion therapy, and insufficient usage of hydroxyurea—an essential medication designed to prevent the sickling of blood cells.

Identifying Risk Factors

The researchers also identified several modifiable risk factors that heighten stroke risks among SCD patients. These include frequent hospitalizations, hypertension, elevated cholesterol levels, and histories of TIAs. Notably, patients with conditions like acute chest syndrome and liver failure were found to be at a greater risk for hemorrhagic strokes.

Call to Action

Dr. Olubusola Oluwole, the study's first author, emphasized the importance of monitoring and managing these risk factors in adults with SCD. "The preventive strategies we know to be effective for the general population are equally vital for SCD patients," Dr. Wun added, pointing to the growing longevity of SCD patients, which heightens their overall stroke risk.

Study Limitations and the Road Ahead

Despite its important findings, the study faced limitations, including insufficient data on tobacco use—a known risk factor for strokes—and a lack of information regarding SCD genotypes. Furthermore, the research had no access to imaging reports, which could have clarified stroke diagnoses, and there is a possibility that the rates of CVEs might be underestimated if strokes occurred outside California or were managed prior to hospitalization.

Conclusion

The researchers hope that their findings will encourage further investigations into stroke risk management for adults with sickle cell disease. The fight against strokes in this vulnerable population is more urgent than ever, and understanding these risks could lead to improved outcomes for patients living with this challenging condition.

Stay tuned as this critical issue unfolds, and join the conversation about improving health care for individuals affected by sickle cell disease.