Abstract 3539: Can Stop Trial Velocity Criteria Be Applied To Iranian Children With Sickle Cell Disease?
Background&Purpose: Although sickle cell disease (SCD) is strongly linked to stroke across all haplotypes in the pediatric population, Iranian children with Saudi-Asian haplotype are less affected by this complication. TCD is known to identify the highest risk group in African-Americans who need to receive and stay on blood transfusions, but it is unclear if the same flow velocity cut-offs can be applied to the Iranian population. We therefore aimed first to evaluate baseline TCD findings in Iranian children with SCD and no prior strokes.
Subjects&Methods: Children with genetically confirmed SCD (Arabian haplotype, homozygote) and without SCD (controls) aged 3 to 16 years were prospectively recruited from pediatric outpatient clinic over a period of 9 months. All children had no previous stroke or any neurologic deficit. No transfusion was given within one month prior to TCD examination and patients were not on any medication that may affect cerebral hemodynamics. We performed TCD examinations in both groups to determine flow velocities in the middle cerebral (MCA) and terminal internal carotid arteries (TICA). Mann-Whitney U test was used to compare TCD variables between the two groups.
Results: Of 74 screened children, 60 met the inclusion/exclusion criteria (62% female; mean age 10±4 years). Baseline characteristics did not differ between the cases and controls, except hemoglobin (Hb) which was significantly lower in the SCD group (mean 8.83±1.43 g/dL vs. 10.3±1.03 g/dL, p<0.001). In children with SCD, the highest MCA MFV (92 cm/s vs. 67 cm/s, p<0.001) and the highest TICA MFV (62 cm/s vs. 45 cm/s, p<0.001) were significantly higher than in controls. Among asymptomatic Iranian children with SCD only 1/30 (3%) had conditional >170 cm/s MFV.
Conclusions: Among Iranian children with asymptomatic SCD and without receiving recent transfusion TCD velocities could be much lower than those observed in STOP studies, and some of the high risk group may be identified with velocities lower than 170 cm/s. A prospective validation of ethnicity-specific diagnostic criteria is warranted.
- © 2012 by American Heart Association, Inc.