Abstract T MP26: Progression Of Asymptomatic Carotid Stenosis: Incidence Of Symptoms And Predictive Factors

Abstract

Background: Given the uncertainty regarding clinical applicability of early treatment trials and lack of data on long-term disease progression, we evaluated the progression of stenosis and development of symptoms on patients with asymptomatic carotid artery stenosis (ACAS) treated with contemporary medical therapy over a prolonged follow up. Methods: Retrospective review of bilateral carotid arteries from consecutive patients diagnosed with moderate or severe ACAS, at our institution between 2000 and 2001. Patient vascular risk factors and treatments, cerebrovascular imaging, ipsilateral symptoms, and revascularization were recorded. Progression of stenosis was defined by change category of stenosis. Factors associated with symptomatic carotid disease were sought using univariate and multivariate logistic regression analysis. Results: We identified 214 patients (58.8% men; median age 70 years) and collected data on 349 vessels. Severe stenosis (>70%) upon diagnosis was present in 92(26.4%) vessels. All patients were on antithrombotics, 97% on antihypertensives, and 95% on statins. Median length of follow up was 13 years (range 5-14) and the mean number of time points with follow-up imaging was 8.1±3.9. Progression of stenosis was observed in 237(67.9%) vessels. 72(20.6%) patients developed symptomatic carotid stenosis (TIA in 14.4%, non-disabling stroke in 4%, and disabling stroke in 2.2%). Median time to appearance of first symptom was 6 years (range 1-13). Revascularization procedures were performed in 118(33.8%) vessels, including 73(61.9%) vessels which had become symptomatic. On multivariate analysis, baseline stenosis (OR 1.65, 95%CI 1.12-2.44), intracranial stenosis > 50% (OR 2.87, 95%CI 1.46-5.62), plaque ulceration (OR 3.41, 95%CI 1.34-8.69), silent infarction (OR 4.25, 95%CI 2.30-7.83), and previous history of TIA/stroke (OR 2.73, 95%CI 1.14-6.54) were associated with development of TIA/stroke ipsilateral to the carotid stenosis. Conclusions: There is a substantial rate of progression of stenosis in patients with asymptomatic carotid atherosclerosis over time despite adequate medical therapy. Over long-term follow up, one in five patients with ACAS developed ipsilateral TIA/stroke.