Low-dose and high-dose acetylsalicylic acid for patients undergoing carotid endarterectomy: a randomised controlled trial

• Published in: The Lancet (British edition) Vol. 353; no. 9171; pp. 2179 - 2184
• Main Authors: Taylor, D Wayne, Barnett, Henry JM, Haynes, R Brian, Ferguson, Gary G, Sackett, David L, Thorpe, Kevin E, Simard, Denis, Silver, Frank L, Hachinski, Vladimir, Clagett, G Patrick, Barnes, R, Spence, J David
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 26-06-1999; Lancet; Elsevier Limited
• Subjects: Acetylsalicylic acid; Acids; Aspirin; Biological and medical sciences; Blood. Blood coagulation. Reticuloendothelial system; Cerebral infarction; Death; Dosage; Evidence-based medicine; Health risks; Heart attacks; Heart surgery; Medical diagnosis; Medical research; Medical sciences; Mortality; Myocardial infarction; Patients; Pharmacology. Drug treatments; Randomization; Risk; Stenosis; Stroke; Surgeons; Surgery; Transient ischemic attack; United States > US; Endoperoxide; Prostaglandin-endoperoxide synthase; Stenosis; Cardiovascular disease; Acetylsalicylic acid; Result; Arterial disease; Vascular disease; Randomization; Surgery; Salicylates; Endarteriectomy; Cerebrovascular disease; Human; Nervous system diseases; Enzyme; Enzyme inhibitor; Controlled therapeutic trial; Intraoperative; Antiplatelet agent; Cerebral disorder; Non steroidal antiinflammatory agent; Analgesic; Carotid; Central nervous system disease; Risk factor; Antipyretic; Double blind study; Oxidoreductases; Effective dose
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(99)05388-X

Endarterectomy benefits certain patients with carotid stenosis, but benefits are lessened by perioperative surgical risk. Acetylsalicylic acid lowers the risk of stroke in patients who have experienced transient ischaemic attack and stroke. We investigated appropriate doses and the role of acetylsalicylic acid in patients undergoing carotid endarterectomy.
In a randomised, double-blind, controlled trial, 2849 patients scheduled for endarterectomy were randomly assigned 81 mg (n=709), 325 mg (n=708), 650 mg (n=715), or 1300 mg (n=717) acetylsalicylic acid daily, started before surgery and continued for 3 months. We recorded occurrences of stroke, myocardial infarction, and death. We compared patients on the two higher doses of acetylsalicylic acid with patients on the two lower doses.
Surgery was cancelled in 45 patients, none were lost to follow-up by 30 days, and two were lost by 3 months. The combined rate of stroke, myocardial infarction, and death was lower in the low-dose groups than in the high-dose groups at 30 days (5·4 vs 7·0%, p=0·07) and at 3 months (6·2 vs 8·4%, p=0·03). In an efficacy analysis, which excluded patients taking 650 mg or more acetylsalicylic acid before randomisation, and patients randomised within 1 day of surgery, combined rates were 3·7% and 8·2%, respectively, at 30 days (p=0·002) and 4·2% and 10·0% at 3 months (p=0·0002).
The risk of stroke, myocardial infarction, and death within 30 days and 3 months of endarterectomy is lower for patients taking 81 mg or 325 mg acetylsalicylic acid daily than for those taking 650 mg or 1300 mg.