Association of Blood Types With Bleeding and Thromboembolic Events in Patients Receiving Continuous Flow Left Ventricular Assist Devices

ABO Blood Group and Bleeding and Survival in VA-ECMO Patients

“…3 More recently, the relationship between ABO blood group and influence on COVID-19 susceptibility and outcomes has piqued the interest of the scientific community, with observational studies concluding that the odds for COVID-19 infection were significantly increased for blood group A and decreased for blood group O, 17,18 reinforcing the idea that ABO phenotypes may affect a multitude of physiologic processes including innate immunity. In the cardiac surgical setting, the relationship between blood group and bleeding has been studied in several different populations, with conflicting results-several smallscale studies of LVAD patients have failed to demonstrate a difference in bleeding rates between O and non-O groups, [19][20][21] whereas Welsby et al found that in CABG patients, O blood group did not have increased blood loss and instead required fewer RBC transfusions intraoperatively compared to their non-O peers. 5 On the other hand, Mazzeffi et al reviewed 111 patients consisting of both VV-ECMO and VA-ECMO and found that group O had a higher rate of massive transfusions (defined as ≥40 RBC units) compared to non-O blood groups and more RBC transfusions after controlling for confounders, although the proportion of patients with bleeding events did not differ with regard to blood type.…”