November 16, 2019 – Rates of stent thrombosis were lowest in patients treated with apixaban rather than a vitamin K antagonist (VKA), such as warfarin, and with aspirin rather than placebo.
Stent thrombosis occurs in less than 1 percent of patients with atrial fibrillation (AF) in the six months after percutaneous coronary intervention (PCI), according to a new analysis of the results from the DCRI-led AUGUSTUS trial.
The analysis also found that rates of stent thrombosis are numerically lower in patients treated with apixaban compared with a vitamin K antagonist (VKA), such as warfarin, and also with aspirin rather than placebo.
The analysis was presented by the DCRI’s Renato Lopes, MD, PhD, (pictured), principal investigator of AUGUSTUS, on Saturday at the American Heart Association Scientific Sessions 2019, in Philadelphia, PA.
The serious clinical impact of stent thrombosis was confirmed by the trial, which involved current generation drug-eluting stents. The analysis found that among patients with definite or probable stent thrombosis, on the day of the thrombotic event, 70 percent (21 patients) also experienced myocardial infarction; 53 percent (16) had an urgent revascularization; and 40 percent (12) died. There were clinical consequences for all patients who had a stent thrombosis.
AUGUSTUS is an international, multicenter randomized trial designed to compare apixaban with vitamin K antagonists and aspirin with placebo. The trial enrolled patients with AF who develop acute coronary syndrome (ACS) and/or undergo PCI and are receiving a P2Y12 inhibitor antiplatelet drug, such as clopidogrel, prasugrel or ticagrelor. A total of 3,498 patients underwent PCI with stenting during their qualifying clinical event and were at risk for stent thrombosis. Overall, there were 57 stent thrombosis events over six months, of which 20 were definite, 10 probable, and 27 possible. Stent thrombosis was adjudicated by a clinical events committee blinded to randomized treatment allocation and classified according to the Academic Research Consortium. The DCRI’s Clinical Events Classification (CEC) group was responsible for the entire adjudication process of the AUGUSTUS trial.
Lopes was lead author of the AHA presentation, titled, “Stent Thrombosis After Percutaneous Coronary Intervention Among Patients With Atrial Fibrillation Treated With Apixaban or Aspirin: Insights From the AUGUSTUS Trial.” Other DCRI authors of the AHA presentation were Daniel Wojdyla, MS; Christopher Granger, MD; and John Alexander, MD, MHS.
The data were published simultaneously in the journal Circulation. In addition to Lopes, Granger, and Alexander, the DCRI’s Laine Thomas, PhD, contributed to the paper.
“Our study provides important insights about the duration of aspirin therapy after PCI in patients with atrial fibrillation,” Lopes said. “For the majority of patients, the AUGUSTUS data support the use of apixaban and a P2Y12 inhibitor without aspirin during the first six months after PCI, based on the almost two-fold increase in bleeding with aspirin use. It is important to keep in mind that almost all patients used aspirin for the initial days after the PCI—on average for six days—before stopping aspirin therapy.”
“However, in patients with a high risk of stent thrombosis and an acceptable risk of bleeding, using aspirin up to 30 days after PCI should be considered, rather than discontinuing aspirin therapy around the time of hospital discharge. Further studies are warranted to identify the patients who might benefit most from this strategy,” said Lopes.
Bristol-Myers Squibb and Pfizer provided funds for the AUGUSTUS study.