Abstract WMP67: Pump Brain - A Leading Cause of Cortical Cerebral Microbleeds

Abstract

Introduction: A major cause of cerebral microbleeds (CMBs) is underrecognized and has been attributed to cerebral amyloid angiopathy (CAA) throughout modern medicine. CMBs are acquired by patients undergoing cardiopulmonary bypass (CPB). CPB is utilized for heart and lung transplants, aorta repairs, valve surgeries, mass resections, and coronary artery bypass grafting (CABG) which alone accounts for 400k patients per year. CABGs can be done off CPB in certain patients. Due to their distribution, these CMBs are attributed to CAA, leading to confounding research and suboptimal patient care, especially in those requiring anticoagulation. Methods: This was a single-center, IRB approved, retrospective cohort study of patients who underwent CPB and had postop MRI between 11/1/11 and 3/1/23. Preop and additional postop MRIs were analyzed if available. Outcomes included number and distribution of CMBs, presence of superficial siderosis, FAZEKAS, and CPB duration. We also analyzed MRIs of patients who had off CPB CABG during the same period. Results: Out of 60 patients who underwent CPB, 60 had predominantly cortical CMBs on postop MRI, with a mean of 50 CMBs, and mean age of 61. The 6 patients who had CABG off CPB had 0 CMBs. Higher CMBs were associated with longer CPB duration and with procedures that are associated with more blood loss (p< 0.05). Despite having CMBs, no CPB patients had superficial siderosis, and they had relatively low FAZEKAS scores. Nineteen of the CPB patients had future MRIs and had no evidence of CMB progression. Conclusion: Cortical CMBs are associated with procedures that use CPB and are not seen in off CPB CABG. The CMBs may be related to utilization of cardiotomy suction that exclusively uses roller pumps. CBP related CMBs are a unique clinical entity that is not associated with the progressive cognitive changes and bleeding risk of CAA. While no significant short-term changes are noted, their mechanism and natural history requires further investigation.