Number and Type of Blood Products Are Negatively Associated With Outcomes After Cardiac Surgery

The association between blood transfusion and adverse outcome is documented in cardiac surgery. However, the incremental significance of each unit transfused, whether red blood cell (RBC) or non-RBC, is uncertain. This study examined the relationship of patient outcomes with the type and number of blood product units transfused.Statewide data from 24 082 adult cardiac surgery patients were included. The relationship with blood transfusion was assessed for morbidity and 30-day mortality using total number of RBC and non-RBC units transfused, specific type of non-RBC units, and different combinations of transfusion (only RBC, only non-RBC, RBC + non-RBC). Multivariable logistic regressions examined these associations.Median age was 66 years (30% female patients), and 51% of patients received a transfusion (31%-66% across hospitals). Risk-adjusted analyses found each blood product unit was associated with 9%, 7%, and 4% greater odds for 30-day mortality, major morbidity, and minor morbidity, respectively (all P < .001). Odds for 30-day mortality were 13% greater with each RBC unit (P < .001) and 6% greater for each non-RBC unit (P < .001). Each unit of fresh frozen plasma (P < .001) and platelets (P < .001) increased the odds for 30-day mortality, but no effect was found for cryoprecipitate (P = .725). Odds for 30-day mortality were lower for non-RBC-only (odds ratio, 0.52; P = .030) and greater for RBC + non-RBC (odds ratio, 2.98; P < .001) compared with RBC-only transfusion.Independent of center variability on transfusion methods, each additional unit transfused was associated with increased odds for complications, with RBC transfusion carrying greater risk compared with non-RBC. Comprehensive evidence-based clinical approaches and coordination are needed to guide each blood transfusion event after cardiac surgery.