Abstract
Objective:
To test the hypothesis that isolated carotid artery stenosis (CAS-isolated) and CAS as part of concurrent coronary artery disease (CAD) and/or peripheral arterial disease (PAD) are two distinct entities.
Methods:
We used the data from Multi-Ethnic Study of Atherosclerosis (MESA) which is a population-based sample of 6,814 men and women aged 44-84 years recruited from six US field centers. Baseline measurements include measurement of coronary calcium using computed tomography; carotid intimal-medial wall thickness and stenosis severity using ultrasonography; and measurement of peripheral vascular disease using ankle and brachial blood pressures. Participants were followed for identification and characterization of cardiovascular events. We defined CAS-isolated based on presence of CAS without any CAD (calcium score of 0 with no history of angina/myocardial infarction) or PAD (arm-brachial index 1.0-1.4).
Results:
Of the 858 persons with CAS ranging in severity from 25 to 100%, 155 (18%) and 703 (82%) were classified as CAS-isolated and CAS-plus, respectively. Persons with CAS-isolated were younger (mean age ±SD; 61±8 versus 70±8, p=0.001) and more likely to be women (63.2% versus 41.8%, p=<.0001). The proportion of persons with hypertension (51.6% versus 66.3%, p=0.0006) and family history of heart attack (37.2% versus 51.1%, p=0.003) were lower among those with CAS-isolated. The proportion of persons with current cigarette smoking (19.6% versus 14.5%, p=0.01) and current alcohol abuse (73.4% versus 62.8%, p=0.03) were higher among CAS-isolated. Persons with CAS-isolated were more likely to have smooth carotid lesions (80.6% versus 69.3%, p=0.004). The relative risk for ischemic stroke was similar among patients with CAS-plus compared with CAS-isolated (RR, 1.1 95% CI 0.3-4.1) after adjustment for age and gender.
Conclusions:
CAS-isolated and CAS-plus appear to be two distinct entities with unique demographic and clinical attributes.