Incidence and Risk Factors for New and Recurrent Infarcts in Adults With Sickle Cell Disease

Abstract

Background: Most adults with sickle cell disease will experience a silent cerebral infarction (SCI) or overt stroke. Identifying patient subgroups with increased stroke incidence is important for future clinical trials focused on stroke prevention. Our 3-center prospective cohort study tested the primary hypothesis that adults with sickle cell disease and SCIs have a greater incidence of new stroke or SCI compared with those without SCI. A secondary aim focused on identifying additional risk factors for progressive infarcts, particularly traditional risk factors for stroke in adults.

Methods and results: This observational study included adults with sickle cell disease and no history of stroke. Magnetic resonance imaging scans of the brain completed at baseline and >1 year later were reviewed by 3 radiologists for baseline SCIs and new or progressive infarcts on follow-up magnetic resonance imaging. Stroke risk factors were abstracted from the medical chart. Time-to-event analysis was utilized for progressive infarcts. Median age was 24.1 years; 45.3% of 95 participants had SCIs on baseline magnetic resonance imaging. Progressive infarcts were present in 17 participants (17.9%), and the median follow-up was 2.1 years. Incidence of new infarcts was 11.95 per 100 patient-years (6.17-20.88) versus 3.74 per 100 patient-years (1.21-8.73) in those with versus without prior SCI. Multivariable Cox regression showed that baseline SCI predicts progressive infarcts (hazard ratio, 3.46 [95% CI, 1.05-11.39]; P=0.041); baseline hypertension was also associated with progressive infarcts (hazard ratio, 3.23 [95% CI, 1.16-9.51]; P=0.025).

Conclusions: Selecting individuals with SCIs and hypertension for stroke prevention trials in sickle cell disease may enrich the study population with those at highest risk for infarct recurrence.

Keywords: hypertension; sickle cell disease; silent infarct; stroke.

Figure .. Kaplan–Meier curve shows time to new infarcts by baseline infarct status.

Adults with sickle cell disease and silent cerebral infarcts at baseline (n=52) were more likely to have new infarcts than those with no infarcts at baseline (n=43) at a median of 2.1 years of follow‐up, log‐rank test P=0.022. SCI indicates silent cerebral infarction.