Microvascular Blood Flow in Sickle Cell Anemia

Inclusion Criteria:

Regadenoson ARM Inclusion Criteria:

• Diagnosis of sickle cell anemia confirmed by hemoglobin analysis

• Ages 18 to 70 years

• Subjects must have laboratory indices as outlined by the protocol

• Reliable IV access as determined by physician

Sickle Cell Controls ARM Inclusion Criteria:

• Diagnosis of sickle cell anemia confirmed by hemoglobin analysis

• Ages 18 to 70 years

Sickle Cell CEU ARM Inclusion Criteria:

• Diagnosis of sickle cell anemia, confirmed by hemoglobin analysis

• Males and females age 18-70 years

Healthy Control ARM Inclusion Criteria:

• African American

• Ages 18 to 70 years

Technique Optimization Control ARM Inclusion Criteria:

-Ages 18 to 70 years

Exclusion Criteria:

Regadenoson ARM Exclusion Criteria

• Hospitalization, emergency department visit or self-reported crisis within last 2weeks for any reason or 4 weeks from acute chest syndrome

• Current physician diagnosis of active asthma (within last 12 months) or current useof asthma medications

• Second or third degree AV block or sinus node dysfunction

• Known or suspected right to left sided cardiac shunts

• History of a bleeding diathesis

• History of clinically overt stroke

• History of severe hypertension not adequately controlled with anti-hypertensivemedications

• Receiving chronic anti-coagulation or anti-platelet therapy

• History of metastatic cancer

• Receiving other investigational study agents, or have received a study agent in thelast 30 days

• Uncontrolled intercurrent illness

• Pregnant or breastfeeding women

• Subjects who have a HIV infection

• Subjects who have had a hematopoietic stem cell transplant

• Subjects who are taking medications that may interact with the investigational agent

• Prior hypersensitivity reactions to either regadenoson or ultrasound contrast agents

Sickle Cell Controls Exclusion Criteria:

• Hospitalization, emergency department visit or self-reported crisis within last 2weeks for any reason or 4 weeks from acute chest syndrome

• Known pregnancy

• Known history of HIV

• Known or suspected right to left sided cardiac shunts

• Receiving other investigational study agents, or have received a study agent withinthe last 30 days

• Subjects who have had a hematopoietic stem cell transplant

• Prior hypersensitivity reactions to ultrasound contrast agents

• History of severe hypertension not adequately controlled with anti-hypertensivemedications

• Uncontrolled intercurrent illness

Sickle Cell CEU ARM Exclusion Criteria:

• Pregnant women

• Subjects who have a HIV infection

• History of stem cell transplant

• Current involvement in a therapeutic clinical trial

• Known or suspected right to left sided cardiac shunts

• Prior hypersensitivity reactions to ultrasound contrast agents

• History of severe hypertension not adequately controlled with anti-hypertensivemedications

• Uncontrolled intercurrent illness

Healthy Control ARM Exclusion Criteria:

• Sickle cell disease or sickle cell trait

• Known or suspected right to left sided cardiac shunts

• Diagnosis of type 1 or type 2 diabetes mellitus

• Hypertension

• History or current diagnosis of dyslipidemia or taking lipid lowering drugs

• Diagnosis of coronary artery disease or peripheral vascular disease

• Body weight greater than 10% of ideal weight

• Uncontrolled intercurrent illness

• Pregnant or breastfeeding women

• Subjects who have a HIV infection

• Prior hypersensitivity reactions to ultrasound contrast agents

Technique Optimization Control ARM Exclusion Criteria:

• Known sickle cell disease or sickle cell trait

• Known or suspected right to left sided cardiac shunts

• Uncontrolled intercurrent illness

• Known pregnant or breastfeeding women

• Prior hypersensitivity reactions to ultrasound contrast agents