Perioperative Anemia and Patient Blood Management in Cardiac Surgery: A Scientific Statement From the American Heart Association

Abstract

Perioperative anemia and red blood cell transfusions are important risk factors for morbidity and mortality in cardiac surgery. Preoperative anemia is common, with up to 50% of patients presenting for cardiac surgery affected. Iron deficiency-the most common and potentially modifiable cause of preoperative anemia-is a major driver of blood transfusions in the cardiac surgical setting, adversely affecting both patient outcomes and resource utilization. Perioperative blood management, a patient-centered approach to blood conservation during cardiac surgery, is a multidisciplinary collaborative effort among anesthesiologists, surgeons, perfusionists, intensivists, and transfusion laboratory teams. Strategies aim to reduce blood loss and transfusions and improve patient outcomes. There has been a recent increase in research related to anemia, iron deficiency, and patient blood management in cardiac surgery. This scientific statement highlights the latest evidence on preoperative anemia assessment and intraoperative blood conservation; discusses considerations for specific patient populations regarding anemia prevalence, treatment, and outcomes; and reviews key challenges and knowledge gaps, with the goal of minimizing the impact of preoperative anemia, intraoperative blood loss, and hemodilution on cardiac surgery outcomes. Key Words: AHA Scientific Statements ◼ anemia ◼ blood transfusion ◼ bloodless medical and surgical procedures ◼ cardiac surgical procedures ◼ operative blood salvage ◼ perioperative care P erioperative anemia has been recognized as an important risk factor for morbidity and mortality in cardiac surgery, leading numerous international subspecialty medical societies 1-7 to strongly recommend preoperative screening and treatment of anemia (Figure). The goal is to achieve higher hemoglobin levels and reduce blood transfusions to decrease morbidity and mortality after cardiac surgery. Despite recent advances in evidence-based guidelines for anemia and patient blood management in cardiac surgery, challenges remain, including difficulty establishing programs to identify and treat preoperative anemia; inconsistent adoption of evidence-based, guideline-directed blood conservation techniques; the continued gap in our understanding of sex and race disparities associated with anemia; and lack of clarity on the mechanism by which perioperative anemia increases long-term mortality risk. This scientific statement highlights the latest evidence on preoperative anemia assessment, treatment strategies, and intraop-erative blood conservation, and reviews key challenges and gaps to be overcome. Perioperative anemia (preoperative, intraoperative, or postoperative) is associated with increased surgical morbidity and mortality. 8-12 The most common cause of preoperative anemia-iron deficiency-is a potentially modifiable condition that adversely affects both patient outcomes and resource utilization. 10,13,14 Despite this, fewer than half of institutions in the United States performing cardiac surgery consistently provide preopera-tive treatment for anemia. 15 Intraoperative anemia based