Abstract 17: Development of High Risk TCD in Sickle Cell Disease
Background: The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) established routine transcranial Doppler ultrasound (TCD) as standard of care. Some information on conversion from low to high risk was derived from the STOP/2 studies but information is needed from “real world” practice to improve TCD screening guidelines.
Subjects and Methods: During STOP and STOP2, 3,837 children, ages 2 to 16 y with SCD-SS or SCD-SBeta-0-thalassemia, underwent screening TCD. The POST-STOP study was designed to follow-up all children who participated in one or both of these trials. 19 of the 26 original study sites participated in POST-STOP, contributing a total of 3,541 (92%) of STOP/STOP2 subjects. Data abstractors visited the clinical sites to extract TCD, neuroimaging and neurological outcome information.
Results: Of the 3,541 subjects, follow-up data were available for 2834 (80%). The mean age at the last TCD STOP/2study was 9.5 years, the mean age at last follow-up in POST-STOP was 19.6 years and the mean duration of follow-up after exiting STOP/STOP2 was 9.2 years. STOP TCD risk stratification was used: normal < 170 cm/sec; conditional 170-199 cm/sec; abnormal >200 cm/sec. Subjects were classified by their highest risk TCD in STOP/STOP 2. The population was divided on this basis into normal (1813 --64%), conditional (478 --17%), abnormal (357-- 13%) or inadequate (186 --7%). Among the 478 with conditional TCD studies in STOP/STOP2, the mean age at last follow-up in POST-STOP was 19.2 years (range 4.9-33.1) and follow-up TCD was obtained on 252 (53%) from 11 months to 16 years after STOP/2 (median 10.4) . Forty three of these had an abnormal TCD (mean age at abnormal was 8.5 years from 3 months to 8.4 years after STOP/2 (median 1.97 years).
1) We could find evidence of follow up TCD for about of half of these children indicating that more needs to be done to insure regular and consistent surveillance of these children who have some elevated risk.
2) Conversions to abnormal TCD were documented. Treatment decisions as well as stroke outcomes for all the 479 with conditional TCD will be derived from adjudication of the complete data set (in progress).
Author Disclosures: R. Adams: None. H. Fullerton: None. J. Kwiatkowski: None. J. Voeks: None.
- © 2015 by American Heart Association, Inc.