The utility of ultrasonic tissue characterization of carotid plaque in the prediction of cardiovascular events in diabetic patients.
OBJECTIVE
The aim of this study was to evaluate whether non-invasive ultrasonic tissue characterization of carotid plaque using gray-scale median (GSM) can be a predictor of future cardiovascular disease (CVD) events in type 2 diabetic patients.


METHODS
A total of 287 type 2 diabetic patients with carotid plaque but without CVD were enrolled (male 72%, mean age 65 ± 7 years). We prospectively evaluated the association between GSM, a quantitative parameter of the plaque echogenicity, and CVD.


RESULTS
The median follow-up period was 55 months, and there were 34 new CVD events. The risk of CVD event was significantly higher in the patients with echolucent (GSM ≤ 37) plaque (n = 67) as compared to those without (n = 220) (HR = 6.99, 95% CI 3.46-14.14, p < 0.001). Cox proportional hazards regression analysis showed that the presence of echolucent plaque (HR = 4.55, 95% CI 2.10-19.84, p < 0.001) as well as plaque thickness (HR = 1.44, 95% CI 1.01-2.06, p = 0.005) were independent predictors of CVD, even after adjustment for other risk factors. Time-dependent receiver-operating-characteristic curve analysis revealed that the addition of plaque thickness to Framingham risk score (FRS) resulted in significant increase in area under the curve (AUC) [from 0.60 (95% CI; 0.49-0.70) to 0.73 (95% CI; 0.63-0.82), p < 0.05]. Notably, the addition of plaque echogenicity (presence/absence of echolucent plaque) to the FRS and plaque thickness resulted in further and significant increase in AUC [from 0.73 (95% CI; 0.63-0.82) to 0.82 (95% CI; 0.75-0.88), p < 0.05].


CONCLUSIONS
Ultrasonic tissue characterization of carotid plaque using the GSM can improve the risk prediction of cardiovascular event in asymptomatic type 2 diabetic patients with carotid plaque.
Department of Metabolic Medicine, Osaka University Graduate School of Medicine, Japan.
Yoko
Y
Irie
Naoto
N
Katakami
Hideaki
H
Kaneto
Mitsuyoshi
M
Takahara
Mayu
M
Nishio
Ryuichi
R
Kasami
Ken'ya
K
Sakamoto
Yutaka
Y
Umayahara
Satoru
S
Sumitsuji
Yasunori
Y
Ueda
Keisuke
K
Kosugi
Iichiro
I
Shimomura
D000368:Aged; D019540:Area Under Curve; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging*; D048909:Diabetes Complications / Q000000981:diagnostic imaging*; D003924:Diabetes Mellitus, Type 2 / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013997:Time Factors; D014463:Ultrasonography
Cardiovascular diseases; Carotid arteries; Carotid ultrasound; Diabetes mellitus; Vulnerable plaque