Losartan for Diffuse Myocardial Fibrosis in Sickle Cell Disease

Inclusion criteria

• 6 years old or older
• Diagnosis of HbSS or Sbeta0-thalassemia
• Ability to cooperate with and undergo CMR without sedation or anesthesia
• Ability to cooperate with and undergo echocardiogram without sedation or anesthesia
• Patients who are on a stable dose of sickle cell disease-modifying therapy: Hydroxyurea, Voxelotor, L-Glutamine, or Crizanlizumab, for 3 months prior to enrollment will be eligible.

Exclusion criteria

• Current chronic transfusion therapy. Patients who received a simple transfusion for an acute event will be eligible 3 months after completion of transfusion
• SCD genotypes other than specified in inclusion criteria
• Any contraindication to CMR such as metallic implants
• Inability to cooperate with CMR or echocardiography imaging
• Known congenital heart disease
• Estimated GFR ≤ to 30 mL/min/1.73 m2 by creatinine clearance
• Pregnant or lactating females or females of child-bearing potential who are unable to use a medically accepted form of contraception throughout the study
• Treatment with a renin-angiotensin pathway inhibitor during the 2 weeks prior to enrollment
• Hypersensitivity to angiotensin receptor II blockers
• Hyperkalemia (K>5.5 mEq/L) on a non-hemolyzed sample despite low-potassium diet
• Hepatic dysfunction defined as serum ALT > 5x the upper normal limit for age
• Current lithium therapy
• Chronic daily use of NSAID
• HIV infection.