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Aspirin and postoperative bleeding after CABG


Clinical bottom line

Preoperative aspirin use increased the risk of postoperative blood transfusion in 1 in 25 patients after CABG, increased the risk of use of frozen plasma by 1 in 40, and increased the risk of reoperation for excessive bleeding by 1 in 60.


VA Ferraris et al. Aspirin and postoperative bleeding after coronary artery bypass grafting. Annals of Surgery 235 6: 820-827.


A US database was used to identify patients undergoing CABG alone or in combination with another procedure. Patients with a history of aspirin ingestion within 12 hours of surgery was identified.

Postoperative banked red cell use and use of frozen plasma, platelets and cryoprecipitate was recorded in all patients, with more than 80 preoperative and intraoperative variables and demographics.


There were 2,606 procedures, and 63% ingested aspirin within 12 hours of surgery. Among aspirin users 23.1% had a postoperative blood transfusion compared with 19% of those not using aspirin. This was a significant difference of 4%, suggesting that use of aspirin increases the risk of blood transfusion by 1 in every 25 CABG operations.

Use of frozen plasma, platelets and cryoprecipitate was 4.5% in aspirin users, compared with 2.1% in non users (statistically significant).

Reoperation for excessive postoperative bleeding was 3.7% versus 2%, again statistically significant. Use of aspirin was associated with an increased risk of reoperation of 1 in 60.


This is an interesting cohort study that also sought information about which patients were most likely to need a transfusion. Female gender, bypass time and age were the main indicators.