The effect of preoperative aspirin-free interval on red blood cell transfusion requirements in cardiac surgical patients

Objective: To compare red blood cell transfusion in first-time coronary artery surgery patients who stopped taking aspirin ≤2 days, 3 to 7 days, or %#62;7 days preoperatively. Design: Observational study. Setting: University-affiliated teaching hospital. Participants: Adult patients (n = 797) undergoing first-time coronary artery surgery on cardiopulmonary bypass who were not receiving other anticoagulant or antiplatelet drugs before surgery. Interventions: None. Measurements and Main Results: Patients were divided into 4 groups based on days since last ingestion of aspirin. Blood products transfused in the groups were (aspirin ≤2 days) (n = 140) 2.2 ± 4 U of red cell concentrate (RCC) (mean ± SD), 1.4 ± 3 U of fresh frozen plasma (FFP), and 2.7 ± 6 U of platelets; (aspirin 3 to 5 days) (n = 255), 1.5 ±2 U of RCC, 0.8 ± 2 U of FFP, and 1.6 ± 4 U of platelets; (aspirin 6 to 7 days) (n = 215), 1.6 ± 3 U of RCC, 0.9 ± 3 U of FFP, and 1.5 ± 3 U of platelets; and (aspirin %#62;7 days) (n = 187), 1.3 ± 2 U of RCC; 0.6 ± 2 U of FFP, and 0.9 ± 2 U of platelets. Conclusion: Patients who stop taking aspirin ≤2 days preoperatively have increased allogenic red blood cell transfusion requirements perioperatively. Patients who stop taking aspirin 3 to 7 days preoperatively have little or no increased requirement for allogenic red blood cell transfusion.