Combined clopidogrel, tranexamic acid improved outcomes in CABG patients

When patients undergoing CABG were exposed to clopidogrel 7 days before surgery in addition to tranexamic acid, the combination reduced the risk for bleeding and provided extra platelet protection, according to data published in JAMA Surgery.

However, taking preoperative clopidogrel alone before surgery increased bleeding and transfusion requirements in this patient population, researchers reported.

The study included 1,173 men and women aged 18 to 85 years undergoing primary and isolated on-pump CABG; 570 patients were randomly assigned tranexamic acid or placebo in a double blind fashion and 552 were analyzed.

Patients were stratified into three observational groups based on preoperative clopidogrel exposure: patients exposed to clopidogrel within 7 days before surgery (early CABG group); those who discontinued for more than 7 days (late CABG group); and those who had no clopidogrel exposure (blank group) before randomization. The three co-primary endpoints were postoperative blood loss, major bleeding, and red blood cell transfusion volume and exposure.

Compared with controls, the researchers reported clopidogrel increased blood loss (mean difference, 270 mL; 95% CI, 135-404); major bleeding (risk difference, 18.5%; 95% CI, 7.85-29.2); volume of red blood cells transfused (mean difference, 2.97 U; 95% CI, 1.51-4.43); and red blood cell transfusion exposure (risk difference, 17.9; 95% CI, 8.51-27.2). Compared with placebo, tranexamic acid reduced blood loss (mean difference, –278 mL; 95% CI, –380 to –176); major bleeding (risk difference, –19.5; 95% CI, –27.7 to –11.4); volume of red blood cells tranfused (mean difference, –2.58 U; 95% CI, –3.61 U to –1.55); and red blood cell transfusion exposure (risk difference, –18.9; 95% CI, –26.4 to –11.4). According to subgroup analysis, researchers reported a significantly enhanced effect of tranexamic acid, particularly in patients with impaired platelet function.

"This extra protection against impaired platelet function improved the bleeding and transfusion outcomes in patients with clopidogrel persistence to a comparable level as that in patients with clopidogrel cessation," Jia Shi, MD, from the State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, Bejiing, China, and researchers wrote in the study. "In light of the current study, the interval between the cessation and the operation is no longer a major determinant of the bleeding and transfusion outcomes in these patients and routine cessation of clopidogrel may not be necessary with the presence of antifibrinolytics, especially in urgent cases and patients with high thrombotic risk."

For more information:

Shi J. JAMA Surg. 2013;doi:10.1001/jamasurg.2013.1560.

Disclosure: The researchers report no relevant financial disclosures.