Paul S. Myles, M.P.H., M.D., Julian A. Smith, F.R.A.C.S., Andrew Forbes, Ph.D., Brendan Silbert, M.B., B.S., Mohandas Jayarajah, M.B., B.S., Thomas Painter, M.B., Ch.B., D. James Cooper, M.D., Silvana Marasco, Ph.D., John McNeil, Ph.D., Jean S. Bussières, M.D., and Sophie Wallace, M.P.H., for the ATACAS Investigators of the ANZCA Clinical Trials Network*
This 5 year multicentre large randomised trial is designed to answer two clinically important questions:
Should low-dose aspirin be continued up until the day of CABG surgery?
Should tranexamic acid be used for all at-risk CABG surgery?
The trial commenced enrolment in April 2006.
Main Study Hypothesis
In patients undergoing elective coronary artery surgery and at increased risk of complications, aspirin and/or tranexamic acid will reduce the incidence of mortality or major morbidity when compared with those not receiving such therapy.
Among 5784 eligible patients, 2100 were enrolled; 1047 were randomly assigned to receive aspirin and 1053 to receive placebo. A primary outcome event occurred in 202 patients in the aspirin group (19.3%) and in 215 patients in the placebo group (20.4%) (relative risk, 0.94; 95% confidence interval, 0.80 to 1.12; P=0.55). Major hemorrhage leading to reoperation occurred in 1.8% of patients in the aspirin group and in 2.1% of patients in the placebo group (P=0.75), and cardiac tamponade occurred at rates of 1.1% and 0.4%, respectively (P=0.08).
Among patients undergoing coronary artery surgery, the administration of preoperative aspirin resulted in neither a lower risk of death or thrombotic complications nor a higher risk of bleeding than that with placebo.
Funding: Australian NHMRC Project Grant (ID 334015)
Registration: ACTRN No. ACTRN012605000557639