Increasing carotid plaque echolucency is predictive of cardiovascular events in high-risk patients.

Abstract

Carotid plaque echolucency seen at ultrasonography (US) is a potential indicator of plaque instability and may help identify patients at risk for major adverse cardiovascular events (MACEs). The authors performed this study to determine whether decreasing gray-scale median (GSM) levels at repeat carotid US examinations are associated with future MACEs. The study was approved by the institutional ethics committee and all patients provided informed consent. The authors prospectively studied 574 patients with carotid plaques of at least 30% from a group of 1268 consecutive patients who were initially asymptomatic with respect to carotid disease. GSM levels were determined with carotid US at baseline and after a median of 7.5 months (range, 6-9 months), and the mean change of the GSM was calculated. Patients were then followed up clinically for a median of 3.2 years for the occurrence of composite MACE. During the initial period, the median change in carotid GSM was 2.9 (interquartile range [IQR], -6.9 to 11.0). Of 574 study participants, 230 (40%) showed a reduction of GSM levels and 344 (60%) showed an increase. MACEs were observed in 177 (31%) of the 574 patients. Adjusted hazard ratios for the lowest quartile (GSM change less than -6.9), the second quartile (GSM change between -6.9 and 2.9), and the third quartile (GSM change between 3.0 and 11.0) were 1.71 (95% confidence interval [CI]: 1.09, 2.66), 1.36 (95% CI: 0.86, 2.16), and 1.22 (95% CI: 0.77, 1.95), respectively, compared with the highest quartile (GSM change greater than 11.0) (P = .018). Increasing echolucency of carotid artery plaques within a 6- to 9-month interval is predictive of midterm clinical adverse events of atherosclerosis.