The association of lesion eccentricity with plaque morphology and components in the superficial femoral artery: a high-spatial-resolution, multi-contrast weighted CMR study

<p>Abstract</p> <p>Background</p> <p>Atherosclerotic plaque morphology and components are predictors of subsequent cardiovascular events. However, associations of plaque eccentricity with plaque morphology and plaque composition are unclear. This study investigated associations of plaque eccentricity with plaque components and morphology in the proximal superficial femoral artery using cardiovascular magnetic resonance (CMR).</p> <p>Methods</p> <p>Twenty-eight subjects with an ankle-brachial index less than 1.00 were examined with 1.5T high-spatial-resolution, multi-contrast weighted CMR. One hundred and eighty diseased locations of the proximal superficial femoral artery (about 40 mm) were analyzed. The eccentric lesion was defined as [(Maximum wall thickness- Minimum wall thickness)/Maximum wall thickness] ≥ 0.5. The arterial morphology and plaque components were measured using semi-automatic image analysis software.</p> <p>Results</p> <p>One hundred and fifteen locations were identified as eccentric lesions and sixty-five as concentric lesions. The eccentric lesions had larger wall but similar lumen areas, larger mean and maximum wall thicknesses, and more calcification and lipid rich necrotic core, compared to concentric lesions. For lesions with the same lumen area, the degree of eccentricity was associated with an increased wall area. Eccentricity (dichotomous as eccentric or concentric) was independently correlated with the prevalence of calcification (odds ratio 3.78, 95% CI 1.47-9.70) after adjustment for atherosclerotic risk factors and wall area.</p> <p>Conclusions</p> <p>Plaque eccentricity is associated with preserved lumen size and advanced plaque features such as larger plaque burden, more lipid content, and increased calcification in the superficial femoral artery.</p

Leg strength in peripheral arterial disease: associations with disease severity and lower-extremity performance

AbstractObjectiveThe purpose of this study was to determine relationships between lower-extremity arterial obstruction, leg strength, and lower-extremity functioning.DesignThe study design was cross-sectional. A total of 514 outpatients (269 with ankle-brachial index [ABI] <0.90), aged 55 and older, were identified from three Chicago-area hospitals. Individuals with history of lower-extremity revascularization were excluded.Main outcome measuresStrength in each leg, 6-minute walk, 4-meter walking velocity, accelerometer-measured physical activity, and a summary performance score were measured. The summary performance score is a composite measure of lower-extremity functioning, ranging from 0 to 12 (12 = best). The leg with the lower ABI was defined as the “index” leg, and the leg with higher ABI was defined as the “contralateral” leg.ResultsIndex leg ABI levels were associated linearly and significantly with strength for hip extension (P < .001), hip flexion (P < .001), knee extension (P = .066), and knee flexion (P = .003), adjusting for known and potential confounders. In adjusted analyses, the index ABI was also associated linearly and significantly with strength in the contralateral leg. Adjusting for confounders, including ABI, knee extension strength, was associated independently with functional measures.ConclusionAmong patients without prior leg revascularization, strength in each leg is highly correlated with the lower-leg ABI. Leg strength is associated independently with functional performance. Further study is needed to determine whether lower-extremity resistance training improves functioning in patients with peripheral arterial disease

Atherosclerotic Risk Factors Are Less Intensively Treated in Patients with Peripheral Arterial Disease Than in Patients with Coronary Artery Disease

OBJECTIVE: To compare rates of therapy for atherosclerotic risk factors between patients with lower extremity peripheral arterial disease (PAD) and patients with coronary artery disease (CAD). DESIGN: Cross-sectional. SETTING: Academic medical center. PATIENTS/PARTICIPANTS: Three hundred forty-nine consecutive patients diagnosed with PAD or CAD identified from the blood flow and cardiac catheterization laboratories, respectively. MEASUREMENTS AND MAIN RESULTS: Participants were interviewed by telephone for medical history as well as therapies prescribed and recommended by their physicians. Among patients with hypercholesterolemia, more CAD patients were taking cholesterol-lowering drugs (58% vs 46%, p = .08) and more CAD patients recalled a physician’s instruction to follow a low-fat, low-cholesterol diet (94% vs 83%, p = .01). CAD patients were more likely to exercise regularly (71% vs 50%, p < .01). Among patients not exercising, more CAD patients recalled a physician’s advice to exercise (74% vs 47%, p < .01). In logistic regression analysis, hypercholesterolemic patients with exclusive CAD were more likely to be treated with drug therapy (odds ratio [OR] 2.3, p = .05). CAD patients were more likely to recall advice to exercise (OR 4.0, p < .001), and more likely to be taking aspirin or warfarin (OR 4.8, p = .01). CONCLUSIONS: Atherosclerotic risk factors are less intensively treated among PAD patients than CAD patients. A number of possible explanations could account for these disparities in therapeutic intensity

Lower extremity peripheral artery disease in the absence of traditional risk factors. The Multi-Ethnic Study of Atherosclerosis.

International audienceOBJECTIVE: Lower-extremity peripheral artery disease (LE-PAD), is strongly related to traditional risk factors (smoking, hypertension, dyslipidemia, diabetes). We hypothesized that the prevalence of LE-PAD in the absence of traditional CVD risk factors is not negligible, and that this condition would remain associated with subclinical atherosclerosis in other territories. METHODS: In the Multi-Ethnic Study of Atherosclerosis, we classified participants without any traditional risk factor according to their ankle-brachial index (ABI) into 3 groups: low (1.30) ABI. Coronary or carotid artery diseases were defined by the presence of any coronary artery calcification (CAC score>0) or carotid plaque, respectively. RESULTS: Among the 6814 participants, 1932 had no traditional risk factors. A low- and high ABI were found in 176 (9%) and 149 (7.8%) cases, respectively. Lower glomerular filtration rate (OR: 0.88/10 units, p=0.04) and higher Interleukin-6 levels (OR: 1.42/natural-log unit, p=0.02) were associated with low ABI. Past smoking (cessation>10 years) and pulse pressure had borderline association with low ABI. In adjusted models, low-ABI was significantly associated with CAC prevalence (OR: 1.22, p<0.03). No significant association was found with carotid plaque. CONCLUSION: In the absence of traditional CVD risk factors, LE-PAD is still common and associated with coronary artery disease

Intrinsic contribution of gender and ethnicity to normal ankle-brachial index values: The Multi-Ethnic Study of Atherosclerosis (MESA)

ObjectiveSeveral studies report a higher prevalence of peripheral arterial disease (PAD) in women and among blacks. These studies based their PAD definition on an ankle-brachial index (ABI) <0.90. We hypothesized that there is an inherent contribution of gender and ethnicity to normal ABI values, independent of biologic and social disparities that exist between gender and ethnic groups. Consequently, an ABI threshold that disregards these fundamental gender-related and ethnicity-related differences could partly contribute to reported prevalence differences.MethodsA cross-sectional study was designed as part of the Multi-Ethnic Study of Atherosclerosis (MESA), a multicenter United States population study. We selected a subgroup of participants with unequivocally normal ABIs (1.00 to 1.30), and additionally excluded participants with any major PAD risk factor (smoking, diabetes, dyslipidemia, hypertension). In a linear model with ABI as the dependent variable, demographic, clinical, biologic, and social variables were introduced as independent factors.ResultsAmong 1775 healthy participants, there was no association between ABI level and subclinical cardiovascular disease (coronary calcium or carotid plaque). Male gender, weight, and high education level were positively correlated with ABI, whereas black race, triglycerides, pack-years (in past smokers), and pulse pressure were negatively correlated. In the fully adjusted model, women had about 0.02 lower ABI values than men, and blacks showed ABI values about 0.02 lower than non-Hispanic whites.ConclusionThese data suggest intrinsic ethnic and gender differences in ABI. Such differences, although small in magnitude, are highly significant and can distort population estimates of disease burden

The epidemiology of subclavian stenosis and its association with markers of subclinical atherosclerosis: the Multi-Ethnic Study of Atherosclerosis (MESA).

International audienceBACKGROUND: Recent studies indicate that subclavian stenosis (SS), diagnosed by a large systolic blood pressure difference (SBPD) between the right and left brachial arteries, is associated with cardiovascular disease (CVD) risk factors and outcomes. We sought to describe the epidemiology of SS and determine its association with markers of subclinical CVD in the baseline cohort of the Multi-Ethnic Study of Atherosclerosis. METHODS: We defined SS by an absolute SBPD>or=15 mmHg. Peripheral artery disease (PAD) was defined by an ankle-brachial index100 vs. score=0; OR=1.43; 1.03-2.01). CONCLUSIONS: The subclavian stenosis is positively associated with other markers of subclinical atherosclerosis