Abstract 11579: Clopidogrel Monotherapy Associates With Increased Mortality Compared With Aspirin Independently of Cardiometabolic Risk Factors

Abstract

Introduction: Antiplatelet monotherapy is recommended for prevention of ischaemic events and death following acute coronary syndrome, particularly if contraindications preclude the use of dual antiplatelet therapy. We aimed to scrutinise the effects of clopidogrel vs aspirin when given as secondary prevention monotherapy on mortality independent of baseline cardiometabolic risk factors in a large real-world UK cohort. Methods: Between 2012 and 2017, consecutive patients (n = 12967) discharged on clopidogrel or aspirin monotherapy were enrolled at our institution in London, UK (median follow-up 244 days, IQR 659). The primary endpoint was all-cause mortality. Kaplan-Meier curves with a log rank test were used to compare all-cause mortality between patients discharged on clopidogrel monotherapy vs aspirin monotherapy. Cox proportional hazards models were constructed to investigate the relationship between antiplatelet monotherapy and all-cause mortality in multivariable analyses. Results: Overall, the primary endpoint of all-cause mortality occurred in 2585 (19.9%) patients: 1642 (18.3%) in the aspirin monotherapy group, compared with 943 (23.5%) on clopidogrel monotherapy (log rank p < 0.001), depicted in Figure 1. Clopidogrel monotherapy conferred an 16% increased risk of mortality compared with aspirin in the unadjusted Cox model (HR 1.16, 95% CI 1.07 - 1.25, p < 0.001). Following adjustment for age, ischaemic heart disease, stroke hypertension, heart failure, atrial fibrillation, diabetes mellitus, chronic kidney disease and chronic obstructive pulmonary disease, clopidogrel remained significantly associated with increased mortality (HR 1.09, 95% CI 1.00 - 1.18, p = 0.045). Conclusions: In this large UK cohort, clopidogrel monotherapy associated with increased all-cause mortality compared with aspirin independently of common cardiometabolic comorbidities.