P2Y12 Inhibitor Monotherapy vs Dual Antiplatelet Therapy by Age After PCI

BACKGROUND: Abbreviated dual antiplatelet therapy (DAPT) followed by P2Y12 inhibitor monotherapy is increasingly used after percutaneous coronary intervention, but whether its effects are consistent across age is uncertain. OBJECTIVES: The authors examined age-related differences in outcomes with P2Y12 inhibitor monotherapy vs 12-month DAPT after percutaneous coronary intervention. METHODS: This post hoc analysis of the Short-Term DAPT After Deployment of Bioabsorbable Polymer Everolimus-Eluting Stent randomized trial stratified 1,387 patients at age 75 years. The primary endpoint was net adverse clinical events (NACE)-major bleeding (Bleeding Academic Research Consortium type 3 or 5) plus major adverse cardiac and cerebrovascular events-through 12 months. RESULTS: Median follow-up was 365 days (Q1-Q3: 353-365); 210 patients (15.1%) were ≥75 years. NACE occurred in 25 of 1,177 patients <75 years (2.4%; 95% CI: 1.4-3.3) and 7 of 210 aged ≥75 years (3.7%; 95% CI: 1.0-6.4). NACE did not differ between monotherapy and 12-month DAPT in patients <75 years (8 of 587 [1.6%; 95% CI: 0.5-2.8] vs 17 of 590 [3.1%; 95% CI: 1.6-4.6]; HR: 0.47; 95% CI: 0.20-1.09) or ≥75 years (3 of 107 [3.3%; 95% CI: 0.0-6.9] vs 4 of 103 [4.2%; 95% CI: 0.1-8.1]; HR: 0.71; 95% CI: 0.16-3.17), with no treatment-age interaction (P = 0.637 dichotomized; P = 0.173 continuous). Major bleeding increased with age, whereas major adverse cardiac and cerebrovascular events remained stable. CONCLUSIONS: P2Y12 inhibitor monotherapy after 3-month DAPT was associated with similar net clinical outcomes to 12-month DAPT in both younger and older patients, with no significant treatment-age heterogeneity. These findings support consideration of abbreviated DAPT as a reasonable treatment option in selected older adults, although larger studies are needed. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03447379.