Stavros K. Kakkos, Ioanna Charalambous, Michael M. Sabetai, Maura B. Griffin, Niki Georgiou, George Geroulakos, Gregory C. Makris, Andrew N. Nicolaides
Academic Vascular Surgery, Imperial College London, London, United Kingdom.
OBJECTIVES: To determine the association between progression of internal carotid artery stenosis and subsequent ipsilateral cerebral ischemic events (AF, TIA or stroke) in the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) Study.
METHODS: 1,121 patients with asymptomatic carotid stenosis 50-99% in relation to the bulb diameter were followed up 6-monthly clinically and with carotid duplex (4-year mean follow). Stenosis was graded using a combination of velocities and velocity ratios, including PSVic/EDVcc, into six groups: 50-60%, 60-70%, 70-80%, 80-90%, 90-95% or 95-99%. Progression or regression was considered present if there was a change to adjacent groups that persisted for at least two consecutive visits.
RESULTS: Regression occurred in 43 (3.8%), no change in 856 (76.4%), progression in 190 (17.0%) and occlusion in 32 (2.8%) patients. Ipsilateral ischemic event rate was 0% with regression, 10.3% with no change, 17.4% with progression and 28.1% with occlusion (chi sq. p<0.001). The corresponding values for stroke were 0%, 4.7%. 7.9% and 12.5%, respectively (chi sq. p=0.029). Using Kaplan-Meier curves, in the subgroup of patients with stenosis 70-95% the average annual ipsilateral ischemic event rate was 2.25% in patients with regression or absence of change and 4.75% in patients with progression (p<0.001; OR 2.15, 95% CI 1.44 to 3.21). The corresponding values for stroke were 1.12% and 2.50% (p=0.025; OR 2.01, 95% CI 1.14 to 3.54). In the subgroup of occlusion the average annual ipsilateral ischemic event rate was 5.6% and for stroke 2.6%. In a logistic regression analysis, the severity of the final stenosis (p=0.005; OR 1.28, 95% CI 1.08 to 1.53) and progression (p=0.034; OR 1.47, 95% CI 1.03 to 2.10) were both independent predictors of ipsilateral ischemic events.
CONCLUSIONS: The degree of stenosis and progression are both associated with the occurrence of ischemic events and stroke. Progression identifies a group at increased risk of stroke.
AUTHOR DISCLOSURES: I. Charalambous: Nothing to disclose; N. Georgiou: Nothing to disclose; G. Geroulakos: Nothing to disclose; M. B. Griffin: Nothing to disclose; S. K. Kakkos: Nothing to disclose; G. C. Makris: Nothing to disclose; A. N. Nicolaides: Nothing to disclose; M. M. Sabetai: Nothing to disclose.
Posted April 2013