Autologous Cold-stored Apheresis Platelets

Two units of autologous platelets will be collected via an apheresis machine that draws blood from an intravenous (IV) line over 1-2 hours, isolates and leukoreduces the platelets by centrifugation and returns the remaining blood back to the patients. Collected autologous platelets will be stored at 1-6℃ without agitation until they are needed during or after surgery or 14 days have elapsed since their collection, after which they will be destroyed as per standard institutional procedures for expired blood products. For the first two platelet orders within 24 hours of cardiopulmonary bypass (CPB) termination, patients will receive their autologous cold-stored platelets. For the third and subsequent doses, patients in the intervention group will receive allogeneic room temperature-stored platelets (standard of care).

Allogeneic platelets will be collected by Canadian Blood Services as per their standard operating procedures. Room temperature stored platelets will be stored at 20-24°C with constant agitation for up to 7 days as per current practices. For any platelet orders within 24 hours of cardiopulmonary bypass (CPB) termination, patients in the control group will receive allogeneic platelets as per usual care.