Aspirin-Free Prasugrel Monotherapy Following Coronary Artery Stenting in Patients With Stable CAD: The ASET Pilot Study

Objectives: The aim of this study was to evaluate the hypothesis that prasugrel monotherapy following successful everolimus-eluting stent implantation is feasible and safe in patients with stable coronary artery disease (CAD).

Background: Recent studies have suggested that short dual-antiplatelet therapy strategies may provide an adequate balance between ischemic and bleeding risks. However, the complete omission of aspirin immediately after percutaneous coronary intervention (PCI) has not been tested so far.

Methods: The study was a multicenter, single-arm, open-label trial with a stopping rule based on the occurrence of definite stent thrombosis (if >3, trial enrollment would be terminated). Patients undergoing successful everolimus-eluting stent implantation for stable CAD with SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) scores <23 were included. All participants were on standard dual-antiplatelet therapy at the time of index PCI. Aspirin was discontinued on the day of the index procedure but given prior to the procedure; prasugrel was administered in the catheterization laboratory immediately after the successful procedure, and aspirin-free prasugrel became the therapy regimen from that moment. Patients were treated solely with prasugrel for 3 months. The primary ischemic endpoint was the composite of cardiac death, spontaneous target vessel myocardial infarction, or definite stent thrombosis, and the primary bleeding endpoint was Bleeding Academic Research Consortium types 3 and 5 bleeding up to 3 months.

Results: From February 22, 2018, to May 7, 2019, 201 patients were enrolled. All patients underwent PCI for stable CAD. Overall, 98.5% of patients were adherent to prasugrel at 3-month follow-up. The primary ischemic and bleeding endpoints occurred in 1 patient (0.5%). No stent thrombosis events occurred.

Conclusions: Aspirin-free prasugrel monotherapy following successful everolimus-eluting stent implantation demonstrated feasibility and safety without any stent thrombosis in selected low-risk patients with stable CAD. These findings may help underpin larger randomized controlled studies to evaluate the aspirin-free strategy compared with traditional dual-antiplatelet therapy following PCI. (Acetyl Salicylic Elimination Trial: The ASET Pilot Study [ASET]; NCT03469856).