Triple versus double antithrombotic therapy after PCI in atrial arrhythmia: a real-world comparative analysis based on initial antithrombotic strategy using TriNetx.

BACKGROUND: The optimal antithrombotic regimen after percutaneous coronary intervention (PCI) in patients with atrial arrhythmias remains uncertain, particularly the balance between double therapy (DT; anticoagulant plus one antiplatelet) and triple therapy (TT; anticoagulant plus dual antiplatelet therapy). Comparative data across coronary artery disease (CAD) phenotypes are limited. METHODS: We performed a retrospective cohort study using the TriNetX database, including adults (≥18 years) with atrial fibrillation/flutter undergoing PCI for CAD. Patients receiving TT or DT were matched 1:1 using propensity scores. The primary outcome was a composite of all-cause mortality, ischemic stroke, gastrointestinal bleeding, recurrent myocardial infarction (MI), and repeat PCI. Prespecified subgroup analyses were conducted by CAD phenotype. RESULTS: After matching, 1,332 patients were included (666 per group). TT was associated with a higher incidence of the composite outcome at 1 month (25.08% vs 17.57%), 6 months (35.74% vs 29.13%), and 12 months (42.79% vs 36.04%). TT was also associated with increased recurrent MI, hospitalization/ER visits, and blood transfusion. In subgroup analyses, outcomes were largely similar in STEMI, whereas TT was associated with higher hospitalization/ER visits in NSTEMI/UA. CONCLUSIONS: Among CAD patients undergoing PCI, TT was associated with worse clinical outcomes than DT, supporting the need for prospective randomized validation.