Real-World Dual Antiplatelet Therapy Use Exceeds Randomized Trials Boundaries With Possible Safety Issues in Patients With Large Artery Atherosclerosis-Insights From the READAPT Study.

Background And Aim: According to randomized controlled trials (RCTs), dual antiplatelet therapy (DAPT) is more effective for secondary prevention of ischemic events attributable to large artery atherosclerosis (LAA) than other mechanisms. We investigated whether real-world application may impact DAPT effectiveness and safety in the REAl-life study on short-term Dual Antiplatelet treatment in Patients with ischemic stroke or Transient ischemic attack (READAPT, NCT05476081).

Methods: READAPT was an observational multicenter study including patients with minor ischemic stroke or TIA treated with short-term DAPT. At 90 days, we assessed primary effectiveness (ischemic recurrence, severe bleeding, or vascular death) and safety (severe to moderate bleeding) outcomes. We explored associations between LAA and outcomes using Cox regression. Within patients with and without LAA, outcomes were compared between subgroups based on age, NIHSS score (for ischemic stroke patients), ABCD score (for TIA patients), presence and number of MRI acute lesions, and DAPT regimen characteristics.

Results: Among 1920 analyzed patients (of 2278 enrolled), 452 had LAA. Unlike RCTs, 21.2% of patients with LAA had NIHSS > 5, and 48.2% received DAPT > 30 days. Patients with LAA had higher bleeding rates (3.5% vs. 2.1%, p = 0.004), primarily hemorrhagic infarctions and moderate bleeding, than those without LAA. However, primary effectiveness outcomes were similar (4.9% vs. 3.5%, p = 0.201) between the groups. In patients with LAA, prolonged DAPT (> 21 days), multiple MRI lesions, age ≥ 65, and loading doses increased bleeding risk.

Conclusions: The real-world DAPT use in patients with LAA exceeds RCTs boundaries with possible drawbacks on treatment safety.