Abstract 4368215: Long-Term Clinical Outcomes between P2Y12 Inhibitor Monotherapy and Prolonged Dual Antiplatelet Therapy in Patients with Poly-vascular Disease: Sub-study of the SMART-CHOICE Randomized Trial

Background: The optimal antiplatelet treatment strategy for poly-vascular disease after percutaneous coronary intervention (PCI) is uncertain. Research Questions: Our study aimed to compare the effects of short-term dual antiplatelet therapy followed by P2Y12 inhibitor monotherapy and prolonged DAPT after PCI, according to the presence of poly-vascular disease. Methods: We conducted a post-hoc analysis of the SMART-CHOICE randomized trial. Patients who underwent PCI were randomly assigned to receive either P2Y12 inhibitor monotherapy (DAPT for 3 months, n=1495) or prolonged DAPT (DAPT for ≥12 months, n=1498) after PCI. Poly-vascular disease was defined as coronaory artery disease with peripheral artery disease or cerebrovascular disease. The primary outcome was major adverse cardiac and cerebrovascular events (MACCE; a composite of all-cause death, myocardial infarction, or stroke). Bleeding Academic Research Consortium (BARC) type 2-5 bleeding, and major bleeding (defined as BARC type 3-5 bleeding) were investigated as secondary outcomes. Clinical follow-up was extended to 3 years. Results: Among the total population (n=2,993), 372 patients were poly-vascular disease (coronary artery disease with peripheral artery disease, n=171; cerebrovascular disease, n=180; both, n=21). Poly-vascular disease patients had a higher rate of MACCEs than those without poly-vascular disease (aHR 1.614, 95%CI 1.133-2.298, *P<0.001). No significant difference in MACCEs was observed between the P2Y12 inhibitor monotherapy and prolonged DAPT (reference) groups, both in poly-vascular disease and non-poly-vascular disease groups (poly-vascular disease: HR 1.396, 95%CI 0.773-2.523, P=0.269; non-poly-vascular disease: HR 0.968, 95%CI 0.682-1.375, P=0.857). There was no significant difference in BARC type 2-5 (p=0.449) and major bleeding (p=0.144) between P2Y12 inhibitor monotherapy and prolonged DAPT in poly-vascular disease group. There was no significant interaction between poly-vascular disease and antiplatelet strategies for the risk of MACCE at 3 years (P inter =0.306). Conclusions: Poly-vascular disease is associated with an increased risk of MACCE after PCI. P2Y12 inhibitor monotherapy after 3-month DAPT may be comparable to prolonged DAPT in terms of ischemic outcomes in patients with poly-vascular disease. Further study is required to assess the efficacy and safety of short-term P2Y12 inhibitor monotherapy after PCI in the poly-vascular disease patient population.