Abstract 4770: Clopidogrel Increases Risk of Blood Transfusion and Hemorrhagic Complication in Patients Undergoing Cardiac Surgery
Objectives: Utilization of the irreversible antiplatelet agent clopidogrel is increasing in acute coronary syndrome patients. As a result more patients are presenting for urgent cardiac surgery with a defect in platelet function. The objective of this study was to determine whether recent clopidogrel administration is predictive of transfusion and hemorrhagic complication (tamponade, return to OR for bleeding) in cardiac surgery patients.
Methods: Retrospective analysis was performed on all patients undergoing isolated CABG, isolated valve, or CABG plus valve at a single center between Jun 2004 and Nov 2007. The outcomes of interest were transfusion, cardiac tamponade, and return to OR for bleeding. The interval between last dose and the date of surgery was calculated and assessed as a risk factor. Logistic regression was used to examine the association of clopidogrel at various intervals (<24h; 24 – 48h; 48 –72h; 72h-5d; >5d or no clopidogrel) and blood transfusion, after adjusting for other relevant risk factors.
Results: Of 3115 patients analyzed, 828 (26.6%) received clopidogrel pre-operatively. Transfusion rates were higher in patients receiving clopidogrel (41.9%) vs. the remainder (29.3%) (p=0.0001). The overall transfusion rate was 32.7%. Clopidogrel use within 24h was associated with the highest rate of transfusion (57.1%) and tamponade or return to OR for bleeding (8.2%). By logistic regression clopidogrel use within 24h (OR 2.4; 1.7–3.4) and 24 – 48h (2.0; 1.3–3.3) emerged as independent predictors of transfusion after adjusting for relevant risk factors.
Conclusion: Patients with recent (<48h) clopidogrel use are at increased risk for transfusion and hemorrhagic complication. Timing of surgery should take into account the interval from the last dose.