Elsevier

The Annals of Thoracic Surgery

Volume 78, Issue 5, November 2004, Pages 1536-1541
The Annals of Thoracic Surgery

Original article: cardiovascular
Does Clopidogrel Increase Blood Loss Following Coronary Artery Bypass Surgery?

https://doi.org/10.1016/j.athoracsur.2004.03.028Get rights and content

Abstract

Background

Clopidogrel (Plavix) is a potent inhibitor of platelet aggregation used concomitantly with percutaneous coronary interventions and in patients with acute coronary syndromes. Its favorable effects on preventing thrombus formation may have deleterious effects on hemostasis in patients undergoing coronary surgery.

Methods

Data were collected prospectively on 312 consecutive urgent or emergent coronary artery bypass patients from July 1999 through April 2001 at a tertiary care center. Patients were stratified into three groups: clopidogrel within 4 days of operation (n = 41), clopidogrel continued until 5 to 8 days before operation (n = 39), and clopidogrel discontinued more than 8 days before operation or were never taking clopidogrel (n = 232).

Results

Preoperative and intraoperative characteristics were similar among all groups. Mediastinal and pericardial chest tube losses in the first 24 hours were 1,044 ± 750 mL in the clopidogrel within 4 days group, 528 ± 250 mL in the clopidogrel 5 to 8 days group, and 573 ± 329 mL in the clopidogrel more than 8 days group (p < 0.01). The mean total blood product transfusions were 12.2 ± 15.4 U, 1.2 ± 2.0 U, and 2.6 ± 5.7 U, respectively (p < 0.001). Reoperation for bleeding was noted in 14.6%, 2.6%, and 1.7%, respectively (p = 0.002). The median hospital lengths of stay for the three groups were 9 days, 7 days, and 7 days, respectively (p = 0.018). There were no statistically significant differences in mortality rate, myocardial infarction, stroke, mediastinitis, or postoperative renal failure among the groups. Multivariable analysis revealed that clopidogrel within 0 to 4 days of operation was an independent predictor of transfusion requirements (OR 4.22, 95% confidence interval [CI] 2.07, 9.34, p = 0.001), intensive care unit (ICU) length of stay (OR 3.14, 95% CI 1.40, 7.04, p = 0.006), and total hospital length of stay (coefficient 7.65, se 2.41, p = 0.002).

Conclusions

Clopidogrel within 4 days of coronary bypass surgery is associated with increased blood losses and reoperation for bleeding and, according to multivariable models, is an independent risk factor for increased transfusion requirements and prolonged ICU and hospital length of stay.

Section snippets

Patients and Methods

Between July 1999 and April 2001, data were collected prospectively using our institutional database on 312 consecutive urgent or emergent CABG patients at the London Health Sciences Center. We observed the use of preoperative CL and its association with morbidity and mortality. Exclusion criteria included elective patient status, concominant valvular procedures, robotic cases, and bleeding disorders identified preoperatively. Patients with an elective status were excluded because they likely

Results

Preoperative patient demographics are outlined in Table 1. There were no clinically or statistically significant differences in age, gender, cardiac risk factors, or CCS class scoring. Patients in the three groups were also no different in terms of preoperative medications that may contribute to postoperative bleeding. However, there was a significant difference in expected hospital mortality and hospital length of stay scores.

The intraoperative data are presented in Table 2. Postoperative

Comment

We have shown that clopidogrel use within 4 days of coronary artery bypass surgery is associated with a number of adverse effects including increased blood loss and reoperation for bleeding. Despite all of the possible confounding factors as reflected in the differences among the groups in predicted hospital mortality and hospital length of stay, clopidogrel was identified as an independent risk factor for increased transfusion requirements and prolonged length of stay in the multivariable

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