Secondary analysis confirms safety of blood thinning agent
Treatment with the blood thinner apixaban was associated with a lower risk of bleeding, death and hospitalization compared with warfarin, regardless of history of prior stroke or blood clot, according to a secondary analysis presented as late breaking science today at the American Stroke Association's International Stroke Conference 2020.
The AUGUSTUS trial, first published in March 2019, found that treatment with apixaban without aspirin resulted in less bleeding and fewer deaths and hospitalizations than treatment with a vitamin K antagonist (like warfarin) plus aspirin among patients with atrial fibrillation and acute coronary syndrome and/or percutaneous coronary intervention treated with a P2Y12 inhibitor. The current study is a secondary analysis of the efficacy and safety outcomes of those treatments.
"We divided the AUGUSTUS study population into two groups: patients with prior stroke/transient ischemic attack/thromboembolism and those with no prior stroke/transient ischemic attack /thromboembolism," said lead study author Maria Cecilia Bahit, M.D., chief of cardiology at INECO Neurociencias in Rosario, Santa Fe, Argentina. "Apixaban was safer than warfarin—causing less major bleeding—and more effective, resulting in less death or hospitalization in both groups."
In the AUGUSTUS trial—a global, multi-center study—4,614 patients with atrial fibrillation and an acute coronary syndrome or those undergoing percutaneous coronary intervention (PCI) with planned treatment with a P2Y12 inhibitor were randomly assigned to receive apixaban or a vitamin K antagonist and to receive aspirin or matching placebo for six months. Of the 4,581 patients with information available about prior stroke, 13.8% had prior stroke/transient ischemic attack or thromboembolism.
This analysis found:
- Patients with prior stroke were at increased risk of ischemic stroke, bleeding, hospitalization or death compared with those with no prior stroke;
- Apixaban without aspirin was associated with the lowest rate of bleeding, death or hospitalization, regardless of history of prior stroke;
- The highest rate of bleeding was seen in patients who received the combination of a vitamin K antagonist plus aspirin;
- The risk of bleeding was higher with aspirin than placebo among patients with no prior events; and
- There was no significant difference between aspirin and placebo observed between patients with and without prior stroke for other clinical outcomes.
"These results reinforce the main results of the AUGUSTUS trial by assuring physicians that even in a high-risk group of patients with prior stroke 'less is more.' In other words, a strategy of apixaban plus a P2Y12 inhibitor without aspirin has the most favorable outcomes, and triple therapy—a vitamin K antagonist plus aspirin plus a P2Y12 inhibitor—should be avoided," said Bahit.