Risk greatest in patients treated within seven days of symptoms

WASHINGTON, D.C.—Details of a study regarding when the greatest risk differences occur between carotid artery stenting and cartoid endarterectomy were released today at the 66th Vascular Annual Meeting presented by the Society for Vascular Surgery®.
Researchers from the departments of vascular surgery and medical statistics, informatics and health economics at Innsbruck Medical University in Innsbruck, Austria, as well those from the department of neurology and stroke unit at the University Hospital in Basel, Switzerland, carried out the research for the Carotid Stenting Trialists’ Collaboration.
Among patients with symptomatic carotid stenosis, carotid artery stenting (CAS) is associated with a higher risk of peri-procedural stroke or death than carotid endarterectomy (CEA). Uncertainty remains whether the balance of risks changes with time since the most recent ischaemic event.
“We investigated the association of time since the qualifying event (0-7 days, 8-14 days and more than 14 days after the qualifying event) with the risk of stroke or death within 30 days after CAS or CEA,” said Barbara Rantner, MD, PhD, from the department of vascular surgery at Innsbruck Medical University. A pooled analysis of data from individual patients randomized in the Endarterectomy vs. Angioplasty in Patients With Symptomatic Severe Carotid Stenosis trial (EVA-3S), the Stent-Protected Angioplasty vs. Carotid Endarterectomy Trial and the International Carotid Stenting Study.
Timing information was available for 2,839 patients. During the first 30 days after intervention, any stroke or death occurred significantly more often in the CAS group (110 of 1,434) compared to the CEA group (54 of 1,405, crude risk ratio 2.0 [95 percent CI (confidence index) 1.5-2.7]. The timing of the intervention modified the treatment benefit: early treated CEA patients (7 days or less) had the lowest periprocedural stroke or death rate (3 of 106).
When comparing data with CEA, early treated CAS patients had a 9.4 percent risk of periprocedural stroke or death (13 of 138; adjusted risk ratio 3.4; 95 percent CI 1.01-11.8) independent from age, sex, source trial and qualifying event. The adjusted risk ratio declined to 2.7 (95 percent CI 0.8-8.9) for carotid stenting between 8-14 days and to 2.6 (95 percent CI 0.8-8.0) for CAS after 14 days. Later CEA increased the risk for perioperative stroke or death compared to early treatment (8-14 days: adjusted risk ratio 1.2; 95 percent CI 0.3-4.4); more than 14 days: adjusted risk ratio 1.4; 95 percent CI 0.4-4.4).
“We found that the increase in risk of CAS compared with CEA appears greatest in patients treated within seven days of symptoms,” said Dr. Ranter, who added that this effect is also apparent independent of age.
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About the Society for Vascular SurgeryThe Society for Vascular Surgery® (SVS) is a not-for-profit professional medical society, composed primarily of vascular surgeons, that seeks to advance excellence and innovation in vascular health through education, advocacy, research, and public awareness. SVS is the national advocate for 3,370 specialty-trained vascular surgeons and other medical professionals who are dedicated to the prevention and cure of vascular disease. Visit its Web site at www.VascularWeb.org® and follow SVS on Twitter by searching for VascularHealth or at http://twitter.com/VascularHealth.

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Journal of Vascular Surgery (June, 2012); 66th Vascular Annual Meeting