Due to the improvements
of medical management in patients with high-grade ACS, there is uncertainty as how to best manage these patients. New studies demonstrate, that a well-treated Obeticholic Acid clinical trial patient with ACS has an annual risk of ipsilateral stroke of only 0.3% [5]. Therefore, 80 patients with an ACS must be treated by a CEA to prevent one disabling stroke. Consequently, the cost-effectiveness of CEA in patients with ACS has been questioned [6]. Nevertheless, ACS accounts for a large burden of stroke, and the majority of ipsilateral strokes are unheralded [7]. Identification of the group of ACS patients at higher risk would improve both risk-benefit and cost-benefit ratios for CEA. Several methods to identify such a high-risk group have been suggested, including ultrasonic detection of asymptomatic embolization. If clinical embolism is a good predictor of the subsequent stroke risk, asymptomatic cerebral emboli might also predict clinical stroke risk [8]. Transcranial Doppler ultrasound (TCD) is a non-invasive technique that can be used to detect circulating NVP-BEZ235 supplier emboli. Several studies evaluated the association between detection of embolic signals and new ischemic events in patients with ACS [9], [10] and [11] and reported different results. Recently a large
prospective and multi-center study (ACES, Asymptomatic Carotid emboli Study) evaluated the relationship between asymptomatic emboli and stroke risk in 467 patients with an ACS of at least 70% [8]. The detection of emboli was associated with an increased risk for ipsilateral TIA and stroke (HR 2.54, 95% CI 1.2–5.36) and in particular for ipsilateral stroke (HR 5.57, 95% CI 1.61–19.32) during 2 years of follow-up even after adjusting for antiplatelet therapy, degree of stenosis, and other risk factors. The absolute annual risk of ipsilateral stroke or TIA between baseline and 2 years was 7.13% in patients with embolic signals and 3.04% in those without, and for ipsilateral stroke was 3.62% in patients
with embolic signals and 0.70% in those without. The authors performed a meta-analysis with all studies available including 1144 patients. The hazard ratio for the risk of ipsilateral Staurosporine in vivo stroke for those with embolic signals compared with those without was 6.63 (95% CI 2.85–15.44) with no heterogeneity between studies (p = 0.33). If TCD is to be used as a clinical tool for risk stratification, improved methods of automated detection of embolic signals are needed [8]. TCD recording itself is simple, non-invasive, and widely used in clinical practice worldwide. However, review of data for the presence of embolic signals is time consuming and relies on trained observers. Automated systems have been developed that have high sensitivity and specificity for detecting the higher intensity embolic signals seen in patients with symptomatic stenosis [12]. However, these systems were less sensitive to the lower intensity embolic signals found in ACS [13].