Use of blood products and risk of stroke after coronary artery bypass surgery

Background. The impact of blood transfusion on the development of post-operative stroke after coronary artery bypass grafting (CABG) is not well established. We, therefore, investigated this issue. Materials and methods. Complete data on pen-operative blood transfusion were available for 2,226 patients who underwent CABG in three Finnish hospitals. Results. Stroke occurred post-operatively in 53 patients (2.4%). Logistic regression showed that pre-operative creatinine (OR 1.003, 95% CI 1.000-1.006), extracardiac arteriopathy (OR 2.344, 95% CI 1.133-4.847), pre-operative atrial fibrillation (OR 2.409, 95% CI 1.149-5.052), and the number of packed red blood cell units transfused (OR 1.121, 95% CI 1.065-1.180) were significantly associated with post-operative stroke. When the various blood product transfusions instead of transfused units were included in the multivariable analysis, solvent/detergent treated plasma (Octaplas (R)) transfusion (OR 2.149, 95% CI 1.141-4.047), but not red blood cell transfusion, was significantly associated with postoperative stroke. Use of blood products ranging from no transfusion (stroke rate 1.6%) to combined transfusion of red blood cells, platelets and Octaplas (R) was associated with a significant increase in post-operative stroke incidence (6.6%, adjusted analysis: OR 1.727,95% 1.350-2.209). Patients who received >2 units of red blood cells, >4 units of Octaplas (R) units and >8 units of platelets had the highest stroke rate of 21%. CART analysis showed that increasing amount of transfused Octaplas (R), platelets and history of extracardiac arteriopathy were significantly associated with post-operative stroke. Conclusions. Transfusion of blood products after CABG has a strong, dose-dependent association with the risk of stroke. The use of Octaplas (R) and platelet transfusions seem to have an even larger impact on the development of stroke than red blood cell transfusions.