Risk for transient ischemic attacks is mainly determined by intima-media thickness and carotid plaque echogenicity

Stenosis severity, plaque morphology, and intima-media thickness (IMT), all have been found to provide prognostic information in patients with asymptomatic carotid artery disease. However, limited data exist on the association between these parameters and the risk for transient ischemic attack (TIA).

We compared the ultrasonographic characteristics of 88 consecutive patients with first TIA without known cardioembolic source with those of 176 propensity-matched asymptomatic control subjects.

IMT was higher in TIA patients compared to control subjects (0.74+/-0.14 mm versus 0.68+/-0.13 mm, p=0.001). Plaques were found in 70.5% of patients and 64.8% of controls (p=0.407). Compared with controls, TIA patients demonstrated more frequently predominantly echolucent lesions (77.4% versus 56.1%, p=0.005) and high-grade carotid stenoses (21.0% versus 9.6%, p=0.042). TIA patients with low-to-moderate grade (<70%) lesions exhibited higher IMT and more prevalent echolucent morphology in comparison with their control counterparts. No significant differences were observed between groups regarding high-grade lesions. In multivariate models, IMT and plaque echogenicity, but not stenosis severity, emerged as independent determinants of risk.

Risk for TIA is primarily associated with IMT and plaque echogenicity, especially in the absence of high-grade lesions. Stenosis severity appears to be of limited prognostic value.