Faculty Bibliography

OBJECTIVE: : To develop a model for the identification of individuals at risk for carotid stenosis (CS) that could be useful in a clinical setting when trying to decide whether screening is worthwhile. BACKGROUND: : Evidence that aggressive medical therapy and life style changes reduce the risk of stroke in individuals with CS is increasing and has led to a renewed interest in screening for CS. METHODS: : Data on demographics and risk factors were obtained from 2,885,257 individuals who had carotid Duplex scans by Life Line Screening between 2003 and 2008. Multivariable logistic regression analysis was used to identify independent risk factors for CS (>50% stenosis). A scoring system was developed where risk factors were assigned a weighted score. Predictive ability was assessed by calculating C statistics and r. RESULTS: : In the screened cohort, 71,004 patients (2.4%) had CS. Independent risk factors include advanced age, smoking, peripheral arterial disease, high blood pressure, coronary artery disease, diabetes, cholesterol, and abdominal aortic aneurysm. African Americans, Asians, and Hispanics had reduced risk than whites. Exercise and consumption of fruit, vegetables, and nuts had a modest protective effect. A predictive scoring system was created that identifies individuals with CS more efficiently (C statistic = 0.753) than previously published models. CONCLUSIONS: : We provide a model that enables identification of individuals who have a high probability of having CS. This model can be helpful in designing targeted screening programs that are cost-effective.

OBJECTIVE: This study sought to determine the relationship between vascular disease in different arterial territories and advanced age. BACKGROUND: Vascular disease in the peripheral circulation is associated with significant morbidity and mortality. There is little data to assess the prevalence of different phenotypes of vascular disease in the very elderly. METHODS: Over 3.6 million self-referred participants from 2003-2008 who completed a medical and lifestyle questionnaire in the United States were evaluated by screening ankle brachial indices <0.9 for peripheral artery disease (PAD), and ultrasound imaging for carotid artery stenosis (CAS) >50% and abdominal aortic aneurysm (AAA) >3cm. Participants were stratified by decade of life. Multivariate logistic regression analysis was used to estimate odds of disease in different age categories. RESULTS: Overall, the prevalence of PAD, CAS, and AAA, was 3.7%, 3.9%, and 0.9%, respectively. Prevalence of any vascular disease increased with age (40-50y: 2%; 51-60y: 3.5%; 61-70y: 7.1%; 71-80y: 13.0%; 81-90y: 22.3%; 91-100y: 32.5%; P<0.0001). Prevalence of disease in each vascular territory increased with age. After adjustment for sex, race/ethnicity, body mass index, family history of cardiovascular disease, smoking, diabetes, hypertension, hypercholesterolemia, and exercise, the odds of PAD (OR 2.14, 95% CI 2.12-2.15), CAS (OR 1.80, 95% CI 1.79-1.81), and AAA (OR 2.33, 95% CI 2.30-2.36]) increased with every decade of life. CONCLUSION: There is a dramatic increase in the prevalence of PAD, CAS, and AAA with advanced age. More than 20% and 30% of octo- and nonagenarians, respectively, have vascular disease in at least 1 arterial territory.

OBJECTIVE: Certain races are known to be at increased risk for stroke, and the prevalence of carotid artery stenosis (CAS) is thought to vary by race. The goal of this report was to study the prevalence of CAS in different races by analyzing a population of subjects who underwent vascular screening examinations. METHODS: The study data were provided by Life Line Screening. The cohort consists of self-referred individuals who paid for vascular screening tests. Subjects <40 and >100 years of age and those who reported a prior stroke or carotid artery intervention were excluded. Of the remaining 3,291,382 subjects, 3.7% did not self-identify a race. CAS was defined as stenosis in either internal carotid artery >/=50% by duplex ultrasound velocity criteria. RESULTS: The 3,291,382 subjects available for analysis consisted of Caucasian (2,845,936 [90%]), African American (97,502 [3.1%]), Hispanic (75,240 [2.4%]), Asian (60,982 [1.9%]), and Native American (87,757 [2.8%]) individuals. The prevalence of CAS was 3.4% in females and 4.2% in males (P