Abstract 4370502: Navigating the Cold Front: Challenges in Cardiac Surgery for Cold Agglutinin Disease

Background: Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia that poses critical challenges during cardiopulmonary bypass (CPB). Exposure to hypothermia during cardiac surgery can lead to hemolysis, transfusion reactions, and disseminated intravascular coagulation (DIC). Meticulous thermal control and interdisciplinary coordination are essential to optimize outcomes. Case: A 68-year-old man with prior mitral valve repair, atrial fibrillation, and multivessel coronary artery disease presented with progressive heart failure. Imaging confirmed severe mitral stenosis, tricuspid regurgitation, and a high coronary calcium burden. He underwent CABG, mitral valve replacement, tricuspid repair, Maze procedure, and left atrial appendage exclusion. Preoperative labs revealed CAD, prompting a normothermic CPB strategy. Despite avoiding hypothermia and using warmed fluids, the patient developed hemolysis, DIC, and multiorgan failure postoperatively. Escalation to intra-aortic balloon pump and VA-ECMO was ineffective, and he ultimately died. Decision-making: The presence of CAD required early hematology input and intraoperative modifications including normothermic perfusion and warmed cardioplegia. Plasmapheresis and complement blockade (e.g., sutimlimab) were not accessible in this urgent setting but represent important future strategies. Despite optimal support, including transfusions and ECMO, the patient experienced progressive hemolysis and hemodynamic collapse. This case highlights the need for proactive planning, especially in patients with known CAD undergoing cardiac surgery. Conclusion: CAD can result in fatal complications during CPB despite best practices. This case underscores the importance of CAD screening, perioperative vigilance, and early use of targeted therapies. It highlights a need for consensus guidelines and research into disease-specific interventions, and reinforces the role of a coordinated, multidisciplinary approach in managing rare hematologic conditions during cardiac surgery.