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

ABO blood group has been shown to be a major determinant of plasma von Willebrand factor (vWF) levels. O blood group is associated with the lowest vWF levels and confers an increased risk of hemorrhagic events, while AB blood group has the highest levels and is associated with thromboembolic events. We hypothesized in extracorporeal membrane oxygenation (ECMO) patients that O blood type would have the highest and AB blood type would have the lowest transfusions, with an inverse relationship to survival. A retrospective analysis of 307 VA-ECMO patients at a major quaternary referral hospital was performed. The distribution of blood groups included 124 group O (40%), 122 group A (40%), 44 group B (14%), and 17 group AB (6%) patients. Regarding usage of packed red blood cells, fresh frozen plasma, and platelets, there was a non-statistically significant difference in transfusions, with group O having the least and group AB having the most requirements. However, there was a statistically significant difference in cryoprecipitate usage when comparing to group O: group A (1.77, 95% CI: 1.05-2.97, P < .05), group B (2.05, 95% CI: 1.16-3.63, P < .05), and group AB (3.43, 95% CI: 1.71-6.90, P < .001). Furthermore, a 20% increase in length of days on ECMO was associated with a 2-12% increase in blood product usage. The cumulative 30-day mortality rate for groups O and A was 60%, group B was 50%, and group AB was 40%; the 1-year mortality rate for groups O and A was 65%, group B was 57%, and group AB was 41%; however, the mortality differences were not statistically significant.