Dual-Antiplatelet Therapy Cessation and Cardiovascular Risk in Relation to Age: Analysis From the PARIS Registry

Objectives: The aim of this study was to examine the association between dual-antiplatelet therapy (DAPT) cessation and cardiovascular risk after percutaneous coronary intervention in relation to age. Background: Examination of outcomes by age after percutaneous coronary intervention is relevant given the aging population. Methods: Two-year clinical outcomes, incidence, and effect of DAPT cessation on outcomes were compared by ages ≤55, 56 to 74, and ≥75 years from the PARIS (Patterns of Non-Adherence to Antiplatelet Regimens in Stented Patients) registry. DAPT cessation included physician-recommended discontinuation, interruption for surgery, and disruption (from noncompliance or bleeding). Clinical endpoints were major adverse cardiac events (MACE) (a composite of cardiac death, definite or probable stent thrombosis, spontaneous myocardial infarction, or clinically indicated target lesion revascularization), a secondary restrictive definition of MACE (MACE2) excluding target lesion revascularization, and bleeding. Results: A total of 1,192 patients (24%) were ≤55 years, 2,869 (57%) were 56 to 74 years, and 957 (19%) were ≥75 years of age. Patients ≥75 years of age had higher DAPT cessation rates and increased risk for MACE2, death, cardiac death, and bleeding compared with younger patients. Discontinuation and interruption were not associated with increased cardiovascular risk across age groups, whereas disruption was associated with increased risk for MACE and MACE2 in younger patients but not in patients ≥75 years of age (p for trend <0.05). Conclusions: Nonadherence and outcomes vary by age, with patients ≥75 years having the highest DAPT cessation rates. We observed no association between outcomes and DAPT cessation in patients ≥75 years, whereas discontinuation was associated with lower MACE rates and disruption with increased MACE rates in patients <75 years.