In the periprocedural period, point estimates for the rates of any stroke or death among asymptomatic patients were low (2.5% in CAS versus 1.4% for CEA; HR, 1.88; 95% CI, 0.79 4.42; P=0.15). The overall estimated 4-year rate of any periproce- dural stroke or death or postprocedural ipsilateral stroke, how- ever, was higher with stenting compared with endarterectomy was not powered to evaluate symptomatic and asymptom- atic patients separately, there was a trend favoring CEA over CAS in both the symptomatic (HR, 1.37; 95% CI, 0.90 2.09; P=0.07) groups. Post hoc analysis found that major and minor stroke negatively affected quality of life at 1 year (Short Form- 36, physical component scale), with minor stroke affecting mental health at 1 year (Short Form-36, mental component scale), but the effect of periprocedural MI did not negatively affect quality of life. Having MI or stroke, including minor stroke, was associated with a higher mortality rate. The advantage of revascularization over medical therapy by itself was not addressed by CREST, which did not randomize a group of asymptomatic subjects to medical therapy without revascularization. Hospital costs for CAS tend to be greater than for CEA.536 538 The National Institute of Neurological Disorders and Stroke sponsored CREST-2 trial will be com- paring centrally managed, intensive medical therapy with or without carotid stenting with embolic protection.539 Screening of Asymptomatic Carotid Stenosis Although carotid artery stenosis is a risk factor for stroke, not every carotid stenosis carries the same risk for future stroke. There have been attempts to identify those patients with carotid stenosis who are at high risk for future events. Two meth- ods have shown promise. The first method uses transcranial Doppler (TCD) to count the number of presumed embolic events, known as high-intensity transient signals per unit time. 