Sickle Cell Disease (SCD) is a condition where red blood cells are shaped like a sickle (a tool with a curved, sharp edge). These abnormal cells can block blood flow and cause pain. This study is looking at whether a special type of blood transfusion, called exchange transfusion, can help adults with SCD who are at high risk for heart problems. This procedure removes some of a patient's blood and replaces it with donated blood. The trial is comparing this treatment to the usual care patients receive. It will last 12 months and involve 150 patients.

• The study lasts for 12 months and involves multiple visits to healthcare facilities.
• Exchange transfusions are already used for treating some SCD complications.
• Participants will be 18 years or older with certain health markers indicating high risk.

Eligibility: Participants need to be 18 or older, have SCD, and meet certain health criteria. They must not have had regular exchange transfusions for at least 60 days. Certain medical conditions or past experiences with blood transfusions might exclude someone from participating.