Hydroxyurea Treatment for Adult Sickle Cell Anemia Patients in Kinshasa

The goal of this clinical trial is to evaluate the efficacy of hydroxyurea (HU) in improving disease severity in adult patients with sickle cell anemia in Kinshasa (Democratic Republic of Congo). This study aims to: * assess the safety and efficacy of HU treatment in the Congolese environment; * assess the reversibility of chronic cardiac lesions. Participants will take hydroxyurea for two years. The effects of the treatment will be evaluated periodically by clinical evaluation, biological tests, and echocardiographic exploration.