Purpose: To determine whether carotid plaque neovascularization as assessed with contrast-enhanced ultrasonography (US) can help predict future coronary events in patients with stable coronary artery disease (CAD). Materials and Methods: The study was approved by the hospital ethics committee, and informed consent was obtained from all patients. Three hundred twelve consecutive patients (228 men; mean age, 63 years 6 9; age range, 42-88 years) with both CAD and at least one carotid plaque thicker than 2.0 mm underwent both standard and contrast-enhanced carotid US. Patients with stable CAD were followed up for 8-47 months (mean, 33 months 6 9) or until a coronary event occurred. Statistical analysis was performed with the Student t test, chi(2) analysis, Kaplan-Meier method, and Cox proportional hazards regression models. Results: Contrast material enhancement of plaque was seen in 42 of 51 patients (82%) with acute coronary syndrome (ACS) and 114 of 261 patients (43.7%) with stable CAD (P<.001). Coronary events occurred during the follow-up period in 24 of 111 patients (21.6%) with contrast material enhancement of plaque and only seven of 137 patients (5.1%) without enhancement (P<.001). In 248 patients with stable CAD and follow-up, Kaplan-Meier analysis demonstrated a significantly higher probability of developing coronary events in patients with contrast material enhancement of plaque than in those without contrast material enhancement (P<.001). The presence of contrast material enhancement of plaque was a significant and independent predictor of future coronary events in patients with stable CAD (odds ratio: 3.90; 95% confidence interval: 1.60, 9.46; P=.003). Conclusion: Contrast material enhancement of plaque is more common in patients with ACS than in those with stable CAD and is a significant and independent predictor of future coronary events in patients with stable CAD, suggesting that noninvasive contrast-enhanced carotid US may be used as a method for risk stratification of patients with stable CAD. (C) RSNA, 2013