Search

The pathophysiology and time course of an individual converting from asymptomatic peripheral artery disease (PAD) to symptomatic claudication is unclear. The objectives of this study were: (1) to characterize the extent of atherosclerotic disease in individuals with an abnormal ankle-brachial index (ABI), but without claudication; and over 1 year of follow-up to (2) evaluate the progression of PAD using ultrasound imaging, (3) determine changes in the ABI and leg pain symptoms, and (4) correlate PAD progression with changes in the ABI and leg symptoms. We hypothesized that PAD progression would be associated with the development of claudication and changes in the ABI, 6-minute walk distance (6-MWD), and walking quality of life. Individuals with a reduced ABI but without typical intermittent claudication noted on community screening were invited to undergo baseline and 1-year follow-up assessment, including duplex ultrasound. The initial and repeat evaluations included measurement of the ABI, lower extremity duplex arterial mapping, and assessment of leg pain and functional status. Of the 50 people studied, 44 (88%) had significant atherosclerotic lesions in the lower extremity arteries, affecting 80 legs. A total of 33 of 50 individuals (66%) returned for the 1-year follow-up visit. On ultrasound examination, two of 18 normal legs developed PAD, and in 48 legs with PAD at baseline, 17 legs (35%) developed new or progressive lesions. Thirteen legs developed new claudication. Overall, there was no significant worsening in the ABI, 6-MWD, or the Walking Impairment Questionnaire (WIQ). However, legs with new lesions or lesion progression were significantly more likely to develop claudication, and the 13 legs (seven subjects) developing claudication showed a significant decline in the 6-MWD. In conclusion, these data indicate that a significant number of people with asymptomatic PAD show progression over 1 year, that such individuals are more likely to develop claudication, and that those developing claudication have a significant decrease in their 6-MWD.

Background: Previous studies have indicated higher rates of peripheral arterial disease (PAD) in blacks than in non-Hispanic whites (NHWs), with limited information available for Hispanics and Asians. The reason for the PAD excess in blacks is unclear., Methods and Results: Ethnic-specific PAD prevalence rates were determined in a randomly selected defined population that included 4 ethnic groups; NHWs, blacks, Hispanics, and Asians. A total of 2343 participants aged 29 to 91 years were evaluated. There were 104 cases of PAD (4.4%). In weighted logistic models with NHWs as the reference group and containing demographic factors only, blacks had a higher PAD prevalence than NHWs (OR=2.30, P<0.024), whereas PAD rates in Hispanics and Asians, although somewhat lower, were not significantly different from NHWs. Blacks had significantly more diabetes and hypertension than NHWs and a significantly higher body mass index. Inclusion of these variables and other PAD risk factors in the model did not change the effect size for black ethnicity (OR=2.34, P=0.048). A model containing interaction terms for black ethnicity and each of the other risk factors revealed no significant interaction terms, which indicates no evidence that blacks were more "susceptible" than NHWs to cardiovascular disease risk factors., Conclusions: Black ethnicity was a strong and independent risk factor for PAD, which was not explained by higher levels of diabetes, hypertension, and body mass index. There was no evidence of a greater susceptibility of blacks to cardiovascular disease risk factors as a reason for their higher PAD prevalence. Thus, the excess risk of PAD in blacks remains unexplained and requires further study.

Objectives: The objective was to assess the prevalence of subclavian artery stenosis (SS) in four cohorts (two free-living and two clinical populations) and determine both risk factors for this condition and the association with other cardiovascular conditions., Background: The prevalence of SS in the general population is unknown, and its association with risk factors and other cardiovascular diseases is not well-established., Methods: A total of 4,223 subjects (2,975 from two free-living cohorts and 1,248 from two clinical cohorts) were included in this cross-sectional analysis. Subclavian artery stenosis was defined as > or =15 mm Hg interarm pressure difference., Results: The prevalence of SS was 1.9% in the free-living cohorts and 7.1% in the clinical cohorts; SS was significantly (p < 0.05) associated with past smoking (odds ratio [OR] = 1.80), current smoking (OR = 2.61), and higher levels of systolic blood pressure (OR = 1.90 per 20 mm Hg). Higher levels of high-density lipoprotein (HDL) cholesterol were inversely and significantly associated with SS (OR = 0.87 per 10 mg/dl). In regression analyses relating SS to other cardiovascular diseases, the only significant finding was with peripheral arterial disease (PAD) (OR = 5.11, p < 0.001)., Conclusions: Significant SS is present in approximately 2% of the free-living population and 7% of the clinical population. Additionally, SS is correlated with current and past smoking histories, systolic blood pressure, HDL levels (inversely), and the presence of PAD. These findings suggest that bilateral brachial blood pressure measurements should routinely be performed in patients with an elevated risk profile, both to screen for SS, and to avoid missing a hypertension or PAD diagnosis because of unilateral pressure measurement in an obstructed arm.