Faculty Bibliography

OBJECTIVE: Although the relationship between physical activity and coronary heart disease is well characterized, a paucity of data exists on physical activity and vascular disease in other arterial territories. This study examined the prevalence of peripheral artery disease (PAD) and carotid artery stenosis (CAS) in association with physical activity. APPROACH AND RESULTS: The association between physical activity and vascular disease was examined in >3 million self-referred US participants in the United States from 2003 to 2008 who completed a medical and lifestyle questionnaire in the Life Line screening program. All subjects were evaluated by screening ankle brachial indices <0.90 for PAD and ultrasound imaging for CAS >50%. Multivariable logistic regression modeling was used to estimate odds of disease. Among 3 250 350 subjects, 63% of the population engaged in some leisure time vigorous physical activity. After adjustment for age, sex, race/ethnicity, hypertension, hypercholesterolemia, smoking status, diabetes mellitus, body mass index, and family history of cardiovascular disease, subjects who reported any physical activity had a significantly lower odds of PAD (odds ratio, 0.64; 95% confidence interval, 0.63-0.65) and CAS (odds ratio, 0.80; 95% confidence interval, 0.79-0.81). The association between physical activity with PAD and CAS was robust when stratified by sex, race, and age categories. Physical activity intensity frequency was associated with lower PAD and CAS in a graded manner (P trend <0.0001 for both). Findings seemed unaffected by confounding by comorbidity or indication. CONCLUSIONS: In a large population-based study, higher levels of physical activity were independently associated with lower odds of vascular disease in the lower extremities and carotid arteries.

BACKGROUND: Platelets are a major contributor to atherothrombosis and may contribute to the heightened risk of perioperative cardiovascular events. We sought to examine changes in platelet activity in subjects undergoing vascular surgery. METHODS: Platelet activity in 18 patients (median age 74, 45% female) undergoing non-emergent open vascular surgery was assessed by light transmission aggregometry in response to saline, epinephrine and adenosine-5 diphosphate (ADP), and by flow cytometric analysis of monocyte-platelet aggregation (MPA). Platelet activity was assessed preoperatively (T1), 1-hour into the operation (T2), 1-hour (T3), 24-hours (T4) and 48-hours post-operatively (T5). Data were compared using the Wilcoxon Signed Ranks Test. Continuous variables are summarized as medians and (interquartile, IQR) ranges. RESULTS: Spontaneous platelet aggregation increased transiently during the surgical period (T1-5.8% [2.4, 10.8], T2-13.5% [9.3, 26.5], T3-7.5% [3.3, 17], T4-10.0% [7.3, 16.3], T5-7.25% [4.5, 29.9], P=0.002). Similar trends in perioperative platelet activity were noted for platelet aggregation in response to epinephrine (P=0.035) and ADP (P=0.036). Using flow cytometry, we found an increase in MPA during the perioperative period (P=0.047), which was most significant between T1 and T3 (P=0.005). CONCLUSIONS: Platelet activity increases significantly during and following open vascular surgery. This data may help explain the pathophysiology of increased thrombotic risk during the perioperative period of vascular surgery.

OBJECTIVES: The prevalence of the "bovine" arch in the population is known (8-25%). However, its prevalence in patients with significant carotid atherosclerosis has never been investigated. Altered flow patterns or turbulence that may occur in these patients may play a causative role in the development of atherosclerotic lesions. The primary purpose of this study was to retrospectively compare the prevalence of aortic arch variants in patients with and without significant carotid artery atherosclerosis, as we hypothesize that carotid atherosclerosis may be more prevalent in patients with a bovine arch due to hemodynamic alterations. A secondary objective was to review radiologist reporting of arch anatomy. METHODS: Single-center, retrospective, case-control study in which 79 patients with hemodynamically significant carotid artery atherosclerosis who underwent computed tomography angiography, magnetic resonance angiography, or unenhanced computed tomography (CT) imaging including the aortic arch were identified. These patients were then compared with 95 randomly selected controls without carotid atherosclerosis that underwent similar imaging during the same time period. Images were independently reviewed by two blinded radiologists, who assessed arch anatomy as normal, bovine, or other variant. The original radiology reports were reviewed for reporting of arch anatomy. RESULTS: In controls, 70% had normal arch anatomy, and 24% had a bovine arch. Among patients with significant carotid disease, these numbers were 70% and 20%, respectively. There was no statistically significant difference between incidence of arch variants in subjects with and without carotid artery atherosclerosis (P=.97). There was good interreader agreement. Among patients with aortic arch anomalies, 20% of the original radiology reports did not mention arch anatomy. CONCLUSIONS: In our experience, percentage of bovine arch anomalies in patients with significant carotid atherosclerosis is not significantly different from those without disease. Clinicians should be aware of the high prevalence of arch anomalies, which can impact endovascular approach and management, and radiologists should be aware of the clinical importance of reporting such variants.

OBJECTIVEThe aim of this study was to investigate the relationship between diabetes and different phenotypes of peripheral vascular disease (lower extremity peripheral artery disease [PAD], carotid artery stenosis [CAS], and abdominal aortic aneurysm [AAA]).RESEARCH DESIGN AND METHODSPrevalence of vascular disease was evaluated in 3,696,778 participants of the Life Line Screening survey between 2003 and 2008. PAD was defined as ankle-brachial pressure index <0.90 or prior revascularization, CAS as >/=50% stenosis or prior revascularization, and AAA as infrarenal aortic diameter >/=3 cm or prior repair. Odds ratios (ORs) and 95% CIs were assessed using logistic regression modeling.RESULTSDiabetes mellitus was present in 10.8% of participants (n = 399,884). Prevalence of PAD, CAS, and AAA were significantly higher (P < 0.0001) in participants with compared with those without diabetes. After multivariate adjustment for baseline demographics and clinical risk factors, a significant interaction existed between diabetes and vascular disease phenotype (P < 0.0001). Diabetes was associated with increased odds of PAD (OR 1.42 [95% CI 1.41-1.4]; P < 0.0001) and CAS (1.45 [1.43-1.47]; P < 0.0001) but decreased odds of AAA (0.86 [0.84-0.88]; P < 0.0001). The strength of association increased with increasing severity of disease in each vascular phenotype, and this association persisted in the population with asymptomatic vascular disease.CONCLUSIONSIn a large population-based study, the association between diabetes and vascular disease differed according to vascular phenotype. Future studies exploring the mechanism for these vascular-specific differences are needed.

Background: While fruit and vegetable (F&V) consumption is associated with reduced risk of stroke and coronary heart disease, there is little data on peripheral artery disease (PAD). We sought to study the association between F&V intake and prevalence of PAD in a large community cohort. Methods: From 2003 - 2008, over 3.5 million self-referred participants at >20,000 US sites completed a medical and lifestyle questionnaire and were evaluated by screening ankle-brachial index <0.9 for PAD. Subjects were queried for frequency of consumption of >3 servings of F&V (<1x/mo, 1x/mo- 1x/wk, 2-3x/wk, 4- 5x/wk, daily). Multivariate logistic regression analysis was used to estimate odds of PAD by F&V intake. Results: Among 3,523,545 individuals, mean age was 63.4 + 10.6 years and 63% were female. F&V intake ranged from 7% (<1x/month) to 29% (daily consumption of >3 servings). After adjustment for age, sex, race, smoking, physical activity, diabetes, hypertension, hyperlipidemia and family history of vascular disease, there was a step-wise inverse association of F&V intake with PAD (P for trend <0.0001; Figure). Compared to subjects with <1x/month consumption of >3 servings of F&V, daily intake was associated with 20% lower odds of PAD (OR 0.800, 95% CI 0.784 - 0.816). Conclusion: We present data from a large community cohort, in which F&V intake exhibited an inverse step-wise relationship with PAD prevalence after correction for multiple established risk factors, suggestive of protective effects in this vascular territory. (Figure Presented)

Objective: Thoracic endovascular aortic repair (TEVAR) for acute uncomplicated type B aortic dissection (TBAD) remains controversial. This study aims to evaluate the impact of TEVAR on mortality, morbidity, length of stay (LOS), and discharge status in patients with acute uncomplicated TBAD.Methods: We analyzed the National Inpatient Sample from 2009 and 2010. Patients were categorized according to the type of treatment: TEVAR or medical management. Outcomes, including mortality, stroke, myocardial infarction (MI), acute renal failure, discharge disposition, and LOS, were compared between the treatment groups.Results: We identified 4706 patients with TBAD. Mean age was 67 years and 55% were male. Treatment options included TEVAR in 504 and medical management in 4202. The overall adjusted in-hospital mortality was similar for both the groups (8.5% for TEVAR vs 10.3% for medical management, P = .224). The TEVAR carried higher risk of stroke (odds ratio [OR] = 1.61, 95% confidence interval [CI] = [1.14-2.27]; P = .0073). The TEVAR was associated with prolonged LOS (12 vs 5.6 days, P < .0001) and patients were less likely to be discharged home (OR 0.73, 95% CI 0.54-0.99; P = .013). When stratified by age, all outcomes were similar between the 2 groups, with the exception of longer LOS with TEVAR.Conclusions: Thoracic endovascular aortic repair for acute uncomplicated TBAD was associated with similar in-hospital mortality, MI, and renal failure as compared to medical management. The TEVAR had higher rate of stroke up to the age 70 years and longer LOS. Because extending TEVAR to less complicated patients could only decrease TEVAR mortality rates, these findings support the more widespread use of TEVAR to treat patients with uncomplicated TBAD.

BACKGROUND: Ankle-brachial index (ABI) testing is a simple, noninvasive method to diagnose peripheral artery disease (PAD) and is associated with all-cause mortality. The association of ABI levels and myocardial infarction (MI) and stroke is less certain. We sought to further characterize the association between ABI levels and history of MI and stroke. METHODS: Using data from the Life Line Screening program, 3.6 million self-referred participants from 2003 to 2008 completed a medical questionnaire and had bilateral ABIs performed. Logistic regression was used to estimate the association between ABI cutoff points (ABI <0.90 and ABI >1.40) and ABI levels with history of MI, stroke, and MI or stroke (MI/stroke). Models were adjusted for age, sex, race/ethnicity, smoking, diabetes, hypertension, hypercholesterolemia, physical activity, and family history of cardiovascular disease. Separate sex-specific models were performed. RESULTS: Overall, 155,552 (4.5%) had an ABI <0.90, and 42,890 (1.2%) had an ABI >1.40. An ABI <0.90 was associated with higher odds of MI (adjusted odds ratio [OR] 1.67, 95% CI 1.63-1.71), stroke (OR 1.77, 95% CI 1.72-1.82), and MI/stroke (OR 1.71, 95% CI 1.67-1.74), all P < .001. An ABI >1.40 was also associated with higher odds of MI (OR 1.19, 95% CI 1.14-1.24), stroke (OR 1.30, 95% CI 1.22-1.38), and MI/stroke (OR 1.22, 95% CI 1.17-1.27), all P < .001. The ORs for MI/stroke for different ABI levels formed a reverse J-shaped curve in both women and men. CONCLUSIONS: In a large national screening database, there is a strong, consistent relationship between ABI levels and a history of prevalent MI, stroke, and MI/stroke.