The resistive index of the internal carotid artery predicted cardiovascular events (RR 1.91 per 1 SD increase; 95% CI 1.34-2.73), performing comparably to intima-media thickness.
Cohort (n=146)
Does the resistive index of the internal carotid artery predict cardiovascular events comparably to the intima-media thickness of the common carotid artery in patients with cardiovascular risk factors or established arteriosclerosis?
Effect estimate: RR 1.91 (95% CI 1.34 to 2.73)
p-value: p=<0.001
BACKGROUND AND PURPOSE: The intima-media thickness (IMT) of the common carotid artery (CCA) is well correlated with the degree of arteriosclerosis and is a predictor of cardiovascular morbidity and mortality. The (hemodynamic) resistive index (RI) of the internal carotid artery (ICA) correlates with the degree of arteriosclerosis just as well as IMT. The aim of the study was to compare the predictive values of RI and IMT with regard to cardiovascular morbidity and mortality. METHODS: A total of 146 patients with cardiovascular risk factors or established arteriosclerosis were included. Duplex sonography of the CCA and ICA was performed, and the IMT and RI were measured in both vessels. During follow-up for a median of 36 months, the occurrence of cardiovascular events (myocardial infarction, stroke, or cardiovascular death) was assessed. RESULTS: Thirty-nine cardiovascular events occurred in 28 patients (19.2%). The relative risk for a cardiovascular event per increase of the IMT by 1 SD (0.16 mm) was 1.53 (95% CI, 1.07 to 2.18) and 1.91 (95% CI, 1.34 to 2.73) for RI ICA (0.08). The event rate in patients with IMT or =0.79 mm and RI ICA > or =0.66, respectively. Log rank analysis showed a continuous increase in the risk of cardiovascular event with increasing range of the IMT (P=0.029) and RI ICA (P<0.001). CONCLUSIONS: The RI ICA is a predictor of cardiovascular mortality and morbidity, at least comparable to the well-established IMT.
Staub et al. (Fri,) conducted a cohort in cardiovascular risk factors or established arteriosclerosis (n=146). Resistive index (RI) of the internal carotid artery (ICA) vs. Intima-media thickness (IMT) of the common carotid artery (CCA) was evaluated on cardiovascular events (myocardial infarction, stroke, or cardiovascular death) (RR 1.91, 95% CI 1.34 to 2.73, p=<0.001). The resistive index of the internal carotid artery predicted cardiovascular events (RR 1.91 per 1 SD increase; 95% CI 1.34-2.73), performing comparably to intima-media thickness.