The effect of medical treatments on stroke risk in asymptomatic carotid stenosis.

BACKGROUND AND PURPOSE Recent evidence suggests current best medical treatment may be sufficient to prevent stroke in patients with asymptomatic carotid stenosis. If this is the case, then it is important to determine risk reduction provided by treatments. Using Asymptomatic Carotid Emboli Study (ACES) prospective data, the effect of current treatment and risk factors on future stroke and transient ischemic attack risk were determined. METHODS Four-hundred seventy-seven patients with asymptomatic carotid stenosis were followed-up every 6 months for 2 years. Changes in risk factors and stroke prevention therapies were reviewed at each visit. Using time-dependent Cox regression, the relationship between current treatment over time was determined and presented as hazard ratios and 95% confidence intervals for risk of stroke, transient ischemic attack, and cardiovascular death end points. RESULTS On multivariate analysis, antiplatelets (P=0.001) and lower mean blood pressure (P=0.002) were independent predictors of reduced risk of ipsilateral stroke and transient ischemic attack. Antiplatelets (P<0.0001) and antihypertensives (P<0.0001) were independent predictors of a lower risk of any stroke or cardiovascular death. CONCLUSIONS Antiplatelet therapy and blood pressure control are the most important factors in reducing short-term stroke and cardiovascular risk in patients with asymptomatic carotid stenosis. More prospective data are required for medical treatments in asymptomatic carotid stenosis in particular for current statin usage.