Advance Targeted Transfusion in Anemic Cardiac Surgical Patients for Kidney Protection: A Proof of Concept Pilot Study

One of the major complications of heart surgery is kidney injury, which occurs in up to 30% of patients and is associated with poor outcomes including death. We have found that patients whose hemoglobin concentration before surgery is lower than normal (i.e., are anemic) are at particularly high risk for this complication, likely because their hemoglobin concentration drops to very low levels during surgery, which reduces delivery of oxygen to the kidneys, increases blood loss, and necessitates blood transfusions. We and others have shown that these events are individually harmful to the kidneys, and can lead to kidney injury. We believe that we can prevent these events from occurring, and as a result reduce the risk of kidney injury, if we transfuse anemic patients at least 1 day before surgery rather than during surgery. In anemic patients undergoing cardiac surgery, prophylactic transfusion of red blood cells (RBCs) before surgery will reduce the risk of acute kidney injury (AKI) after surgery by mitigating three inter-related risk factors for AKI.