Volume 180 - Issue 2
Aspirin for cardiovascular disease prevention
Author: Joseph Hung
Med J Aust 2004; 180 (2): 94. || doi: 10.5694/j.1326-5377.2004.tb05815.x
Published online: 19 January 2004
Published online: 19 January 2004
Joseph Hung
Associate Professor, School of Medicine and Pharmacology, University of Western Australia, and Head of Department, Cardiovascular Medicine, Sir Charles Gairdner Hospital, Verdun Street, Nedlands, WA 6009. jhungATcyllene.uwa.edu.au
In reply: Janssen and Henshaw are correct to point out that aspirin fails to prevent 80% of recurrent serious vascular events among high-risk patients. However, to put this into perspective, simple treatment with aspirin produces about the same relative risk reduction as treatment with a statin or the angiotensin-converting enzyme inhibitor, ramipril, among patients at high risk of vascular events.1-3
Janssen and Henshaw raise the concept of aspirin resistance and the role of a screening test. However, aspirin resistance is a poorly defined term, and could mean the clinical inability of aspirin to protect individuals from arterial thrombotic events, or laboratory measures indicating the failure of aspirin to inhibit platelet activity. There is currently no specific, accurate, and reproducible measure of the antiplatelet effects of aspirin, nor are there methods that can reliably predict the clinical efficacy of aspirin.4 For now, with high-risk patients, doctors should:
ensure that patients comply with aspirin therapy along with other proven preventive treatments;
avoid regular concomitant use of non-steroidal anti-inflammatory drugs with aspirin because of the potential for competitive inhibition;5 and
consider the addition of clopidogrel to therapy with aspirin, so as to block other pathways of platelet activation not blocked by aspirin, particularly in patients who experience thrombotic complications during aspirin therapy.1
References
- Hung J, for the Medical Issues Committee of the National Heart Foundation of Australia. Aspirin for cardiovascular disease prevention. Med J Aust 2003; 179: 147-152. <eMJA full text>
- Genest J, Pedersen TR. Prevention of cardiovascular ischemic events: high-risk and secondary prevention. Circulation 2003; 107: 2059-2065.
- The Heart Outcomes Prevention Evaluation Study Investigators. Effect of an angiotensin-converting-enzyme-inhibitor, ramipril, on cardiovascular events in high-risk patients. N Engl J Med 2000; 342: 145-153. i1082893
- Eikelboom JW, Hankey GJ. Aspirin resistance: a new independent predictor of vascular events? J Am Coll Cardiol 2003; 41: 966-968. i1082895
- Kurth T, Glynn RJ, Walker AM, et al. Inhibition of clinical benefits of aspirin on first myocardial infarction by nonsteroidal antiinflammatory drugs. Circulation 2003; 108: 1191-1195. i1082897