The perioperative risks of carotid endarterectomy outweigh the benefits in symptomatic women with less than 70% stenosis, especially those with few other risk factors, Sonia Alamowich, M.D., reported
For women with lesser stenosis, medical management is both safer and more effective than surgery, according to Dr. Alamowich of Tenon Hospital in Paris, and her colleagues.
They performed subset analysis on pooled data from two trials of endarterectomy. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) involved 873 women and 2,012 men with internal carotid artery stenosis and a history of recent transient ischemic attack or nondisabling ischemic stroke, randomized to best medical treatment alone or in combination with carotid endarterectomy. The Aspirin and Carotid Endarterectomy (ACE) trial was designed to study the best dose of aspirin to reduce the risk of stroke and death in 2,804 women and men scheduled for endarterectomy.
The 30-day risk of death after endarterectomy was higher in women than men (2.3% vs. 0.8%). Women's higher mortality was due largely to fatal stroke, based on a subgroup analysis of 1,415 patients in the surgery arm of NASCET and 1,148 symptomatic patients from ACE (Stroke 2005;36:27–31).
With stenosis of at least 70%, the absolute stroke risk reduction 5 years after endarterectomy was 15.1% for women and 17.3% for men. When carotid stenosis fell within the 50% to 69% range, endarterectomy reduced women's absolute stroke risk by only 3% versus 10% for men. Endarterectomy bestowed no significant benefit on either women or men with carotid stenosis under 50%.
When managed medically, men and women with at least 70% stenosis of the carotid had a similar 5-year absolute relative risk of ipsilateral ischemic stroke (28.9% vs. 29.8%). With stenosis from 50% to 69%, medically managed women had a lower risk of stroke, compared with men (16.1% vs. 25.3%).
Women scoring 0–3 on the stroke prognosis instrument measuring risk factors had no likelihood of stroke, and those scoring 2–5 had 6.3% risk of stroke. The stroke risk in men in the same two score categories were 18.5% and 19.2%, respectively. Thus, men with moderate stenosis benefit from surgery, regardless of their risk score.
Only 29% of the women with 50%–69% stenosis fell in that group with the highest risk score of 8–15. Carotid endarterectomy reduced their absolute relative risk of stroke by 8.9%; surgery provided little or no benefit to women with low risk scores and only moderate stenosis.
Certain stroke risk factors were significantly more common among women: obesity, smoking, hypertension, and hyperlipidemia. Other risk factors were significantly more likely among men: prior stroke and/or myocardial infarction, intermittent leg pain, irregular or ulcerated internal carotid artery plaques, occluded contralateral internal carotid arteries, and brain infarct on imaging.