Stroke Prevention in Sickle Cell Anemia (STOP 2)

This study has been completed.
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI) Identifier:
First received: August 21, 2000
Last updated: February 17, 2016
Last verified: October 2005
To determine how long blood transfusions are needed for primary stroke prevention. Also, to determine the duration of risk associated with abnormal transcranial Doppler ultrasound (TCD) and to determine the specificity of the stroke risk model developed in STOP 1 in patients with abnormal TCD measurements.

Condition Intervention Phase
Blood Disease
Cerebrovascular Accident
Anemia, Sickle Cell
Procedure: Blood Transfusion
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Primary Purpose: Prevention

Resource links provided by NLM:

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: July 2000
Study Completion Date: February 2006
Detailed Description:


Without intervention, 11 percent of children with sickle cell anemia will sustain a stroke before the age of 20. The STOP 2 follows on the recently completed NHLBI trial, Stroke Prevention Trial in Sickle Cell Anemia (STOP 1), which found that patients at high risk for stroke could be identified using transcranial Doppler (TCD) ultrasound, and that the incidence of stroke could be reduced by 90 percent in those children by periodic blood transfusion for at least 36 months. However, chronic intermittent blood transfusions are cumbersome, expensive and associated with morbidity from iron overload. Thus, this study to determine if transfusion can be safely halted after 30 months of treatment is critically important to the continued clinical care of patients with sickle cell disease at risk for stroke.


In this multicenter, randomized clinical trial, 100 children will be randomized to continue to receive periodic transfusion therapy and 50 to discontinue receiving periodic transfusion therapy. The primary endpoint will be the reversion of the transcranial Doppler velocity levels to greater than 200 cm/second, indicating return of increased risk for overt stroke. Recruitment will be in two phases. Phase I will include those patients who began transfusions before April 1, 1999. These will come mainly from the STOP 1 cohort. Those who begin transfusions after April 1, 1999 but before April 1, 2001 will be eligible for Phase II of recruitment. All patients will receive quarterly TCD examinations. Patients who revert to high risk will be offered return to transfusion. The overall design includes a three month start-up, the two phases of recruitment (established STOP patients and new patients) for a total of 36 months, 18 months of observations after recruitment ends and then 3 months of wrap-up.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.


Ages Eligible for Study:   2 Years to 20 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
No eligibility criteria
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Please refer to this study by its identifier: NCT00006182

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
Investigator: Robert Adams Georgia Regents University
Investigator: Donald Brambilla New England Research Institutes, Inc.
  More Information

Publications automatically indexed to this study by Identifier (NCT Number): Identifier: NCT00006182     History of Changes
Other Study ID Numbers: 68  U01HL052016 
Study First Received: August 21, 2000
Last Updated: February 17, 2016
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Anemia, Sickle Cell
Hematologic Diseases
Anemia, Hemolytic
Anemia, Hemolytic, Congenital
Brain Diseases
Cardiovascular Diseases
Central Nervous System Diseases
Cerebrovascular Disorders
Genetic Diseases, Inborn
Nervous System Diseases
Vascular Diseases processed this record on May 24, 2016