HYPOECHOIC PLAQUE AT US OF THE CAROTID-ARTERY - AN INDEPENDENT RISK FACTOR FOR INCIDENT STROKE IN ADULTS AGED 65 YEARS OR OLDER

PURPOSE: To investigate the association between incident (first) strok e and the echogenicity of internal carotid arterial plaque at ultrason ography (US). MATERIALS AND METHODS: A cohort of 4,886 individuals who , at baseline, were 65 years of age or older and without symptoms of c erebrovascular disease was followed up for an average of 3.3 years. Ba seline clinical findings were from color Doppler and duplex US studies of the carotid arteries and a record of traditional risk age, sex, pr esence of diabetes mellitus, pack-years of cigarette smoking, presence of hypertension, elevated systolic and diastolic blood pressures, ele vated low-density lipoprotein cholesterol level. RESULTS: incident str okes, excluding hemorrhagic strokes and strokes of cardiac origin, wer e seen in 104 individuals (2.1%) at risk. Age- and sex-adjusted odds r atios for incident stroke were significant for hypoechoic plaque (odds ratio, 2.53; 95% CI, 1.42, 4.53). After controlling for risk factors in a Cox proportional hazards model, the relative risk (RR) of inciden t stroke was 1.72 (P = .015) for hypoechoic plaque and 2.32 (P = .004) for internal carotid arterial narrowing of at least 50%. In addition, hypoechoic plaque (RR, 2.78; CI, 1.36, 5.69) and 50%-100% stenosis (R R, 3.08; CI, 1.28,,7.41)were associated with ipsilateral, nonfatal str oke. CONCLUSION: In asymptomatic adults aged 65 years or older, the ri sk of incident stroke was associated with two US features: hypoechoic internal carotid arterial plaque and an estimated internal carotid art erial stenosis of 50%-100%.