Aspirin in Patients with Chronic Coronary Syndrome Receiving Oral Anticoagulation

Background: The appropriate antithrombotic regimen for patients with chronic coronary syndrome who are at high atherothrombotic risk and receiving long-term oral anticoagulation remains unknown.

Methods: We conducted a multicenter, double-blind, randomized, placebo-controlled trial in France involving patients with chronic coronary syndrome who had undergone a previous stent implantation (>6 months before enrollment) and were at high atherothrombotic risk and currently receiving long-term oral anticoagulation. The patients were randomly assigned in a 1:1 ratio to receive aspirin (100 mg once daily) or placebo; all the patients continued to receive their current oral anticoagulation therapy. The primary efficacy outcome was a composite of cardiovascular death, myocardial infarction, stroke, systemic embolism, coronary revascularization, or acute limb ischemia. The key safety outcome was major bleeding.

Results: A total of 872 patients underwent randomization; 433 were assigned to the aspirin group, and 439 to the placebo group. The trial was stopped early at the advice of the independent data and safety monitoring board after a median follow-up of 2.2 years because of an excess of deaths from any cause in the aspirin group. A primary efficacy outcome event occurred in 73 patients (16.9%) in the aspirin group and in 53 patients (12.1%) in the placebo group (adjusted hazard ratio, 1.53; 95% confidence interval [CI], 1.07 to 2.18; P = 0.02). Death from any cause occurred in 58 patients (13.4%) in the aspirin group and in 37 (8.4%) in the placebo group (adjusted hazard ratio, 1.72; 95% CI, 1.14 to 2.58; P = 0.01). Major bleeding occurred in 44 patients (10.2%) in the aspirin group and in 15 patients (3.4%) in the placebo group (adjusted hazard ratio, 3.35; 95% CI, 1.87 to 6.00; P<0.001). A total of 467 and 395 serious adverse events were reported in the aspirin group and placebo group, respectively.

Conclusions: Among patients with chronic coronary syndrome at high atherothrombotic risk who were receiving an oral anticoagulant, the addition of aspirin led to a higher risk of cardiovascular death, myocardial infarction, stroke, systemic embolism, coronary revascularization, or acute limb ischemia than placebo, as well as higher risks of death from any cause and major bleeding. (Funded by the French Ministry of Health and Bayer Healthcare; ClinicalTrials.gov number, NCT04217447.).