ATACAS Trial: Aspirin and Traxemic Acid Trial for Coronary Artery Surgery

ATACAS- Tranexamic acid

The final results of the Aspirin and Tranexamic Acid for Coronary Artery Surgery (ATACAS) trial were showcased before a large audience of anaesthetists from around the world at the American Society of Anesthesiologist’s (ASA) 2016 annual meeting in Chicago by principal investigator Professor Paul Myles on October 23.

The trial received $A4.5 million from the National Health and Medical Research Council, and from ANZCA Research Foundation. The trial was run out of The Alfred and Monash University, in Melbourne. The aspirin arm of the trial was published in the New England Journal of Medicine in 2016 (N Engl J Med 2016;374:728-37).

ATACAS has been running for more than 10 years at 31 cardiac hospitals across seven countries. Now the ATACAS-tranexamic acid results have been published in the New England Journal of Medicine. This study provided definitive results that tranexamic acid can be safely used to reduce the bleeding complications in patients undergoing cardiac surgery without increasing the risk of thrombosis after cardiac surgery.

The results build on the evidence-base in anaesthesia, pain and perioperative medicine needed to improve patient outcomes. 

About the trial
Patients undergoing cardiac surgery are commonly administered tranexamic acid to reduce the complications of bleeding, however, it is unclear whether it increases the risk of heart attack or stroke.

ATACAS was designed as a multi-centre, double-blinded, randomised two-by-two factorial trial, in which 4631 high-risk patients undergoing coronary artery surgery where randomly assigned to receive tranexamic acid or placebo.

The primary outcome was a composite of death and thrombotic complications (non-fatal myocardial infarction, stroke, pulmonary embolism, renal failure and bowel infarction) within 30 days of surgery. Secondary endpoints included blood transfusion, re-operation, respiratory failure, and hospital length-of-stay.

Of the 4631 patients who consented to participate in the trial, 2311 were randomly assigned to receive tranexamic acid (50- 100mg/kg) and 2310 received a matched placebo. The primary outcome occurred in 386 (16.7 per cent) patients assigned to the tranexamic group and 420 (18.1 per cent) patients in the placebo group (relative risk, 0.92; 95 per cent confi dence interval, 0.81 to 1.05; P=0.22).

Major haemorrhage or tamponade requiring re-operation occurred in 1.4 per cent and 2.9 per cent of patients (P=0.001), any blood transfusion within 24 hours of surgery was used in 31 per cent and 49 per cent of patients (P<0.001), seizures occurred in 0.7 per cent and 0.1 per cent of patients (P=0.002) in the tranexamic acid and placebo groups respectively.

In patients having coronary artery surgery, pre-operative tranexamic acid reduced bleeding complications without increasing the risk of death and thrombotic complications within 30 days of surgery. Tranexamic acid was associated with a small increase risk of post-operative seizures. Tranexamic acid can be safely used for coronary artery surgery.





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