Abstract 17149: Aspirin and the Risk of Cardiovascular Events in Atherosclerosis Patients With and Without Prior Ischemic Events
Introduction: Aspirin is recommended after an acute ischemic event for prevention of future cardiovascular events; however, the benefit among those with stable atherosclerosis without a prior ischemic event is poorly defined.
Hypothesis: In patients with stable atherosclerosis and no prior ischemic event, aspirin might not be associated with a reduction in ischemic events.
Methods: This is an observational analysis of patients from the Reduction of Atherothrombosis for Continued Health (REACH) registry. Patients were divided into those with a prior ischemic event (i.e., unstable angina, acute myocardial infarction, transient ischemic attack, or acute ischemic stroke; n=21,724) and those with stable atherosclerosis, but no prior ischemic event (i.e., stable angina with documented coronary artery disease, history of coronary revascularization, ≥ 1 carotid plaque, asymptomatic carotid stenosis ≥70%, carotid revascularization, ankle brachial index < 0.9, or lower extremity revascularization or amputation; n=11,872). Propensity score matching was used for the analyses. Aspirin use was updated at each clinic visit and considered as a time varying covariate. The primary outcome was the first occurrence of all-cause death, myocardial infarction, or stroke, while the secondary outcome was the first occurrence of cardiovascular death, myocardial infarction, or stroke.
Results: The median follow-up was 44 months. In the group with a prior ischemic event, aspirin use was associated with a lower risk of the primary outcome (18.9% vs 20.6%; hazard ratio [HR] 0.74, 95% CI 0.61-0.90, p<0.01), and a non-significant lower risk of the secondary outcome (15.2% versus 15.8%; HR 0.81, 95% CI 0.65-1.01, p=0.06). In the group without a prior ischemic event, aspirin use was not associated with a lower risk of the primary outcome (14.7% versus 16.1%; HR 0.91, 95% CI 0.70-1.19, p=0.49), or the secondary outcome (10.7% versus 10.5%; HR 1.03, 95% CI 0.73-1.45, p=0.86).
Conclusion: In this observational analysis of outpatients with stable atherosclerosis, but no prior ischemic event, the use of aspirin was not associated with a reduction in the risk of cardiovascular events. In such patients, the utility of long-term aspirin may need to be reconsidered.
Author Disclosures: A.A. Bavry: Research Grant; Significant; Gilead. Honoraria; Significant; American College of Cardiology. I.Y. Elgendy: None. A.N. Mahmoud: None. Y. Elbez: None. E. Sorbets: None. P.G. Steg: Research Grant; Significant; Sanofi, Servier, Merck. Consultant/Advisory Board; Modest; Amarin, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, CSL-Behring, Daiichi-Sankyo, GlaxoSmithKline, Lilly, Merck, Janssen, Novartis, Pfizer, The Medicines Company, Regeneron, Roche, The Medicines Company. Consultant/Advisory Board; Significant; Zeneca, Sanofi, Servier. D.L. Bhatt: Research Grant; Significant; Amarin, Amgen, AstraZeneca, Bristol-Myers Squibb, Eisai, Ethicon, Forest Laboratories, Ischemix, Medtronic, Pfizer, Roche, Sanofi Aventis, The Medicines Company.
- © 2016 by American Heart Association, Inc.