The antifibrinolytic tranexamic acid (TXA) reduced serious bleeding without a significant effect on major vascular outcomes in patients undergoing noncardiac surgery at risk for these complications in the POISE-3 trial.
TXA cut the primary efficacy outcome of life-threatening, major, and critical organ bleeding at 30 days by 24% compared with placebo (9.1% vs. 11.7%; hazard ratio [HR], 0.76; P < .0001).
The primary safety outcome of myocardial injury after noncardiac surgery (MINS), nonhemorrhagic stroke, peripheral arterial thrombosis, and symptomatic proximal venous thromboembolism (VTE) at 30 days occurred in 14.2% vs.. 13.9% of patients, respectively (HR, 1.023). This failed, however, to meet the study›s threshold to prove TXA noninferior to placebo (one-sided P = .044).
There was no increased risk for death or stroke with TXA, according to results published April 2 in the New England Journal of Medicine.
Principal investigator P.J. Devereaux, MD, PhD, Population Health Research Institute and McMaster University, Hamilton, Ontario, Canada, pointed out that there is only a 4.4% probability that the composite vascular outcome hazard ratio was above the noninferiority margin and that just 10 events separated the two groups (649 vs.. 639).
“Healthcare providers and patients will have to weigh a clear beneficial reduction in the composite bleeding outcome, which is an absolute difference of 2.7%, a result that was highly statistically significant, versus a low probability of a small increase in risk of the composite vascular endpoint, with an absolute difference of 0.3%,” a nonsignificant result, Dr. Devereaux said during the formal presentation of the results at the hybrid annual scientific sessions of the American College of Cardiology.
The findings, he said, should also be put in the context that 300 million adults have a major surgery each year worldwide and most don’t receive TXA. At the same time, there’s an annual global shortage of 30 million blood product units, and surgical bleeding accounts for up to 40% of all transfusions.
“POISE-3 identifies that use of TXA could avoid upwards of 8 million bleeding events resulting in transfusion on an annual basis, indicating potential for large public health and clinical benefit if TXA become standard practice in noncardiac surgery,” Dr. Devereaux said during the late-breaking trial session.
TXA is indicated for heavy menstrual bleeding and hemophilia and has been used in cardiac surgery, but it is increasingly being used in noncardiac surgeries. As previously reported, POISE showed that the beta-blocker metoprolol lowered the risk for myocardial infarction (MI) but increased the risk for severe stroke and overall death, whereas in POISE-2, perioperative low-dose aspirin lowered the risk for MI but was linked to more major bleeding.
The cumulative data have not shown an increased risk for thrombotic events in other settings, Dr. Devereaux told this news organization.
“I’m a cardiologist, and I think that we’ve been guilty at times of always only focusing on the thrombotic side of the equation and ignoring that bleeding is a very important aspect of the circulatory system,” he said. “And I think this shows for the first time clear unequivocal evidence that there’s a cheap, very encouraging, safe way to prevent this.”
“An important point is that if you can give tranexamic acid and prevent bleeding in your cardiac patients having noncardiac surgery, then you can prevent the delay of reinitiating their anticoagulants and their antiplatelets after surgery and getting them back on the medications that are important for them to prevent their cardiovascular event,” Dr. Devereaux added.
Discussant Michael J. Mack, MD, commented that TXA, widely used in cardiac surgery, is an old, inexpensive drug that “should be more widely used in noncardiac surgery.” Dr. Mack, from Baylor Scott & White Health, Dallas, added that he would limit it to major noncardiac surgery.