Comparison of global estimates of prevalence and risk factors for peripheral artery disease in 2000 and 2010: a systematic review and analysis

BACKGROUND

Lower extremity peripheral artery disease is the third leading cause of atherosclerotic cardiovascular morbidity, following coronary artery disease and stroke. This study provides the first comparison of the prevalence of peripheral artery disease between high-income countries (HIC) and low-income or middle-income countries (LMIC), establishes the primary risk factors for peripheral artery disease in these settings, and estimates the number of people living with peripheral artery disease regionally and globally.

METHODS

We did a systematic review of the literature on the prevalence of peripheral artery disease in which we searched for community-based studies since 1997 that defined peripheral artery disease as an ankle brachial index (ABI) lower than or equal to 0·90. We used epidemiological modelling to define age-specific and sex-specific prevalence rates in HIC and in LMIC and combined them with UN population numbers for 2000 and 2010 to estimate the global prevalence of peripheral artery disease. Within a subset of studies, we did meta-analyses of odds ratios (ORs) associated with 15 putative risk factors for peripheral artery disease to estimate their effect size in HIC and LMIC. We then used the risk factors to predict peripheral artery disease numbers in eight WHO regions (three HIC and five LMIC).

FINDINGS

34 studies satisfied the inclusion criteria, 22 from HIC and 12 from LMIC, including 112,027 participants, of which 9347 had peripheral artery disease. Sex-specific prevalence rates increased with age and were broadly similar in HIC and LMIC and in men and women. The prevalence in HIC at age 45-49 years was 5·28% (95% CI 3·38-8·17%) in women and 5·41% (3·41-8·49%) in men, and at age 85-89 years, it was 18·38% (11·16-28·76%) in women and 18·83% (12·03-28·25%) in men. Prevalence in men was lower in LMIC than in HIC (2·89% [2·04-4·07%] at 45-49 years and 14·94% [9·58-22·56%] at 85-89 years). In LMIC, rates were higher in women than in men, especially at younger ages (6·31% [4·86-8·15%] of women aged 45-49 years). Smoking was an important risk factor in both HIC and LMIC, with meta-OR for current smoking of 2·72 (95% CI 2·39-3·09) in HIC and 1·42 (1·25-1·62) in LMIC, followed by diabetes (1·88 [1·66-2·14] vs 1·47 [1·29-1·68]), hypertension (1·55 [1·42-1·71] vs 1·36 [1·24-1·50]), and hypercholesterolaemia (1·19 [1·07-1·33] vs 1·14 [1·03-1·25]). Globally, 202 million people were living with peripheral artery disease in 2010, 69·7% of them in LMIC, including 54·8 million in southeast Asia and 45·9 million in the western Pacific Region. During the preceding decade the number of individuals with peripheral artery disease increased by 28·7% in LMIC and 13·1% in HIC.

INTERPRETATION

In the 21st century, peripheral artery disease has become a global problem. Governments, non-governmental organisations, and the private sector in LMIC need to address the social and economic consequences, and assess the best strategies for optimum treatment and prevention of this disease.

FUNDING

Peripheral Arterial Disease Research Coalition (Europe).

Rivaroxaban with or without aspirin in patients with stable peripheral or carotid artery disease: an international, randomised, double-blind, placebo-controlled trial

BACKGROUND

Patients with peripheral artery disease have an increased risk of cardiovascular morbidity and mortality. Antiplatelet agents are widely used to reduce these complications.

METHODS

This was a multicentre, double-blind, randomised placebo-controlled trial for which patients were recruited at 602 hospitals, clinics, or community practices from 33 countries across six continents. Eligible patients had a history of peripheral artery disease of the lower extremities (previous peripheral bypass surgery or angioplasty, limb or foot amputation, intermittent claudication with objective evidence of peripheral artery disease), of the carotid arteries (previous carotid artery revascularisation or asymptomatic carotid artery stenosis of at least 50%), or coronary artery disease with an ankle-brachial index of less than 0·90. After a 30-day run-in period, patients were randomly assigned (1:1:1) to receive oral rivaroxaban (2·5 mg twice a day) plus aspirin (100 mg once a day), rivaroxaban twice a day (5 mg with aspirin placebo once a day), or to aspirin once a day (100 mg and rivaroxaban placebo twice a day). Randomisation was computer generated. Each treatment group was double dummy, and the patient, investigators, and central study staff were masked to treatment allocation. The primary outcome was cardiovascular death, myocardial infarction or stroke; the primary peripheral artery disease outcome was major adverse limb events including major amputation. This trial is registered with ClinicalTrials.gov, number NCT01776424, and is closed to new participants.

FINDINGS

Between March 12, 2013, and May 10, 2016, we enrolled 7470 patients with peripheral artery disease from 558 centres. The combination of rivaroxaban plus aspirin compared with aspirin alone reduced the composite endpoint of cardiovascular death, myocardial infarction, or stroke (126 [5%] of 2492 vs 174 [7%] of 2504; hazard ratio [HR] 0·72, 95% CI 0·57-0·90, p=0·0047), and major adverse limb events including major amputation (32 [1%] vs 60 [2%]; HR 0·54 95% CI 0·35-0·82, p=0·0037). Rivaroxaban 5 mg twice a day compared with aspirin alone did not significantly reduce the composite endpoint (149 [6%] of 2474 vs 174 [7%] of 2504; HR 0·86, 95% CI 0·69-1·08, p=0·19), but reduced major adverse limb events including major amputation (40 [2%] vs 60 [2%]; HR 0·67, 95% CI 0·45-1·00, p=0·05). The median duration of treatment was 21 months. The use of the rivaroxaban plus aspirin combination increased major bleeding compared with the aspirin alone group (77 [3%] of 2492 vs 48 [2%] of 2504; HR 1·61, 95% CI 1·12-2·31, p=0·0089), which was mainly gastrointestinal. Similarly, major bleeding occurred in 79 (3%) of 2474 patients with rivaroxaban 5 mg, and in 48 (2%) of 2504 in the aspirin alone group (HR 1·68, 95% CI 1·17-2·40; p=0·0043).

INTERPRETATION

Low-dose rivaroxaban taken twice a day plus aspirin once a day reduced major adverse cardiovascular and limb events when compared with aspirin alone. Although major bleeding was increased, fatal or critical organ bleeding was not. This combination therapy represents an important advance in the management of patients with peripheral artery disease. Rivaroxaban alone did not significantly reduce major adverse cardiovascular events compared with asprin alone, but reduced major adverse limb events and increased major bleeding.

FUNDING

Bayer AG.

2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health. These guidelines, based on systematic methods to evaluate and classify evidence, provide a cornerstone of quality cardiovascular care.

In response to reports from the Institute of Medicine1 ,2 and a mandate to evaluate new knowledge and maintain relevance at the point of care, the ACC/AHA Task Force on Clinical Practice Guidelines (Task Force) modified its methodology.3 –5 The relationships among guidelines, data standards, appropriate use criteria, and performance measures are addressed elsewhere.5

Lower Extremity Peripheral Artery Disease: Contemporary Epidemiology, Management Gaps, and Future Directions: A Scientific Statement From the American Heart Association

Lower extremity peripheral artery disease (PAD) affects >230 million adults worldwide and is associated with increased risk of various adverse clinical outcomes (other cardiovascular diseases such as coronary heart disease and stroke and leg outcomes such as amputation). Despite its prevalence and clinical importance, PAD has been historically underappreciated by health care professionals and patients. This underappreciation seems multifactorial (eg, limited availability of the first-line diagnostic test, the ankle-brachial index, in clinics; incorrect perceptions that a leg vascular disease is not fatal and that the diagnosis of PAD would not necessarily change clinical practice). In the past several years, a body of evidence has indicated that these perceptions are incorrect. Several studies have consistently demonstrated that many patients with PAD are not receiving evidence-based therapies. Thus, this scientific statement provides an update for health care professionals regarding contemporary epidemiology (eg, prevalence, temporal trends, risk factors, and complications) of PAD, the present status of diagnosis (physiological tests and imaging modalities), and the major gaps in the management of PAD (eg, medications, exercise therapy, and revascularization). The statement also lists key gaps in research, clinical practice, and implementation related to PAD. Orchestrated efforts among different parties (eg, health care providers, researchers, expert organizations, and health care organizations) will be needed to increase the awareness and understanding of PAD and improve the diagnostic approaches, management, and prognosis of PAD.

Epidemiology of Peripheral Artery Disease and Polyvascular Disease

Atherosclerotic lower extremity peripheral artery disease (PAD) is increasingly recognized as an important cause of cardiovascular morbidity and mortality that affects >230 million people worldwide. Traditional cardiovascular risk factors, including advanced age, smoking, and diabetes, are strongly linked to an increase risk of PAD. Although PAD has been historically underappreciated compared with coronary artery disease and stroke, greater attention on PAD in recent years has led to important new epidemiological insights in the areas of thrombosis, inflammation, dyslipidemia, and microvascular disease. In addition, the concept of polyvascular disease, or clinically evident atherosclerosis in multiple arterial beds, is increasingly identified as a particularly malignant cardiovascular disease worthy of special clinical attention and further study. It is noteworthy that PAD may increase the risk of adverse outcomes in similar or even greater magnitude than coronary disease or stroke. In this review, we highlight important new advances in the epidemiology of PAD with a particular focus on polyvascular disease, emerging biomarkers, and differential risk pathways for PAD compared with other atherosclerotic diseases.

Burden of Coronary Artery Disease and Peripheral Artery Disease: A Literature Review

BACKGROUND

Atherothrombotic disease, including coronary artery disease (CAD) and peripheral artery disease (PAD), can lead to cardiovascular (CV) events, such as myocardial infarction, stroke, limb ischemia, heart failure, and CV death.

AIM

Evaluate the humanistic and economic burden of CAD and PAD and identify unmet needs through a comprehensive literature review.

METHODS

Relevant search terms were applied across online publication databases. Studies published between January 2010 and August 2017 meeting the inclusion/exclusion criteria were selected; guidelines were also included. Two rounds of screening were applied to select studies of relevance.

RESULTS

Worldwide data showed approximately 5-8% prevalence of CAD and 10-20% prevalence of PAD, dependent on the study design, average age, gender, and geographical location. Data from the REACH registry indicated that 18-35% of patients with CAD and 46-68% of patients with PAD had disease in one or more vascular beds. Use of medication to control modifiable CV risk factors was variable by country (lower in France than in Canada); statins and aspirin were the most widely used therapies in patients with chronic disease. Survival rates have improved with medical advancements, but there is an additional need to improve the humanistic burden of disease (i.e., associated disability and quality of life). The economic burden of atherothrombotic disease is high and expected to increase with increased survival and the aging population.

CONCLUSION

CAD and PAD represent a substantial humanistic and economic burden worldwide, highlighting a need for new interventions to reduce the incidence of atherothrombotic disease.

Arterial calcification and bone physiology: role of the bone-vascular axis

Bone never forms without vascular interactions. This simple statement of fact does not adequately reflect the physiological and pharmacological implications of the relationship. The vasculature is the conduit for nutrient exchange between bone and the rest of the body. The vasculature provides the sustentacular niche for development of osteoblast progenitors and is the conduit for egress of bone marrow cell products arising, in turn, from the osteoblast-dependent haematopoietic niche. Importantly, the second most calcified structure in humans after the skeleton is the vasculature. Once considered a passive process of dead and dying cells, vascular calcification has emerged as an actively regulated form of tissue biomineralization. Skeletal morphogens and osteochondrogenic transcription factors are expressed by cells within the vessel wall, which regulates the deposition of vascular calcium. Osteotropic hormones, including parathyroid hormone, regulate both vascular and skeletal mineralization. Cellular, endocrine and metabolic signals that flow bidirectionally between the vasculature and bone are necessary for both bone health and vascular health. Dysmetabolic states including diabetes mellitus, uraemia and hyperlipidaemia perturb the bone-vascular axis, giving rise to devastating vascular and skeletal disease. A detailed understanding of bone-vascular interactions is necessary to address the unmet clinical needs of an increasingly aged and dysmetabolic population.

Early adult to midlife cardiovascular risk factors and cognitive function

BACKGROUND

Studies have linked midlife and late-life cardiovascular risk factors (CVRFs) to cognitive function, yet little is known about CVRF exposure in early adulthood and subsequent cognitive function. In addition, most studies rely on single assessments of CVRFs, which may not accurately reflect long-term exposure. We sought to determine the association between cumulative exposure to CVRFs from early to middle adulthood and cognitive function at midlife.

METHODS AND RESULTS

In a prospective study of 3381 adults (age, 18-30 years at baseline) with 25 years of follow-up, we assessed cognitive function at year 25 (2010-2011) with the Digit Symbol Substitution Test, Stroop Test, and Rey Auditory Verbal Learning Test analyzed with standardized z scores. The primary predictor was 25-year cumulative exposure estimated by areas under the curve for resting systolic and diastolic blood pressures, fasting blood glucose, and total cholesterol. Higher cumulative systolic and diastolic blood pressures and fasting blood glucose were consistently associated with worse cognition on all 3 tests. These associations were significant primarily for exposures above recommended guidelines; cognitive test z scores were between 0.06 and 0.30 points less, on average, for each 1-SD increase in risk factor area under the curve after adjustment for age, race, sex, and education (P<0.05 for all). Fewer significant associations were observed for cholesterol.

CONCLUSIONS

Cumulative exposure to CVRFs from early to middle adulthood, especially above recommended guidelines, was associated with worse cognition in midlife. The meaning of this association and whether it warrants more aggressive treatment of CVRFs earlier in life require further investigation.

Associations between conventional cardiovascular risk factors and risk of peripheral artery disease in men

CONTEXT

Previous studies have examined the associations of individual clinical risk factors with risk of peripheral artery disease (PAD), but the combined effects of these risk factors are largely unknown.

OBJECTIVE

To estimate the degree to which the 4 conventional cardiovascular risk factors of smoking, hypertension, hypercholesterolemia, and type 2 diabetes are associated with the risk of PAD among men.

DESIGN, SETTING, AND PARTICIPANTS

Prospective study of 44,985 men in the United States without a history of cardiovascular disease at baseline in 1986; participants in the Health Professionals Follow-up Study were followed up for 25 years until January 2011. The presence of risk factors was updated biennially during follow-up.

MAIN OUTCOME MEASURE

Clinically significant PAD defined as limb amputation or revascularization, angiogram reporting vascular obstruction of 50% or greater, ankle-brachial index of less than 0.90, or physician-diagnosed PAD.

RESULTS

During a median follow-up of 24.2 years (interquartile range, 20.8-24.7 years), there were 537 cases of incident PAD. Each risk factor was significantly and independently associated with a higher risk of PAD after adjustment for the other 3 risk factors and confounders. The age-adjusted incidence rates were 9 (95% CI, 6-14) cases/100,000 person-years (n = 19 incident cases) for 0 risk factors, 23 (95% CI, 18-28) cases/100,000 person-years (n = 99 incident cases) for 1 risk factor, 47 (95% CI, 39-56) cases/100,000 person-years (n = 176 incident cases) for 2 risk factors, 92 (95% CI, 76-111) cases/100,000 person-years (n = 180 incident cases) for 3 risk factors, and 186 (95% CI, 141-246) cases/100,000 person-years (n = 63 incident cases) for 4 risk factors. The multivariable-adjusted hazard ratio for each additional risk factor was 2.06 (95% CI, 1.88-2.26). Men without any of the 4 risk factors had a hazard ratio of PAD of 0.23 (95% CI, 0.14-0.36) compared with all other men in the cohort. In 96% of PAD cases (95% CI, 94%-98%), at least 1 of the 4 risk factors was present at the time of PAD diagnosis. The population-attributable risk associated with these 4 risk factors was 75% (95% CI, 64%-87%). The absolute incidence of PAD among men with all 4 risk factors was 3.5/1000 person-years.

CONCLUSION

Among men in this cohort, smoking, hypertension, hypercholesterolemia, and type 2 diabetes account for the majority of risk associated with development of clinically significant PAD.

Models of accelerated sarcopenia: critical pieces for solving the puzzle of age-related muscle atrophy

Sarcopenia, the age-related loss of skeletal muscle mass, is a significant public health concern that continues to grow in relevance as the population ages. Certain conditions have the strong potential to coincide with sarcopenia to accelerate the progression of muscle atrophy in older adults. Among these conditions are co-morbid diseases common to older individuals such as cancer, kidney disease, diabetes, and peripheral artery disease. Furthermore, behaviors such as poor nutrition and physical inactivity are well-known to contribute to sarcopenia development. However, we argue that these behaviors are not inherent to the development of sarcopenia but rather accelerate its progression. In the present review, we discuss how these factors affect systemic and cellular mechanisms that contribute to skeletal muscle atrophy. In addition, we describe gaps in the literature concerning the role of these factors in accelerating sarcopenia progression. Elucidating biochemical pathways related to accelerated muscle atrophy may allow for improved discovery of therapeutic treatments related to sarcopenia.

Migraine and risk of cardiovascular diseases: Danish population based matched cohort study

OBJECTIVE

To examine the risks of myocardial infarction, stroke (ischaemic and haemorrhagic), peripheral artery disease, venous thromboembolism, atrial fibrillation or atrial flutter, and heart failure in patients with migraine and in a general population comparison cohort.

DESIGN

Nationwide, population based cohort study.

SETTING

All Danish hospitals and hospital outpatient clinics from 1995 to 2013.

PARTICIPANTS

51 032 patients with migraine and 510 320 people from the general population matched on age, sex, and calendar year.

MAIN OUTCOME MEASURES

Comorbidity adjusted hazard ratios of cardiovascular outcomes based on Cox regression analysis.

RESULTS

Higher absolute risks were observed among patients with incident migraine than in the general population across most outcomes and follow-up periods. After 19 years of follow-up, the cumulative incidences per 1000 people for the migraine cohort compared with the general population were 25 v 17 for myocardial infarction, 45 v 25 for ischaemic stroke, 11 v 6 for haemorrhagic stroke, 13 v 11 for peripheral artery disease, 27 v 18 for venous thromboembolism, 47 v 34 for atrial fibrillation or atrial flutter, and 19 v 18 for heart failure. Correspondingly, migraine was positively associated with myocardial infarction (adjusted hazard ratio 1.49, 95% confidence interval 1.36 to 1.64), ischaemic stroke (2.26, 2.11 to 2.41), and haemorrhagic stroke (1.94, 1.68 to 2.23), as well as venous thromboembolism (1.59, 1.45 to 1.74) and atrial fibrillation or atrial flutter (1.25, 1.16 to 1.36). No meaningful association was found with peripheral artery disease (adjusted hazard ratio 1.12, 0.96 to 1.30) or heart failure (1.04, 0.93 to 1.16). The associations, particularly for stroke outcomes, were stronger during the short term (0-1 years) after diagnosis than the long term (up to 19 years), in patients with aura than in those without aura, and in women than in men. In a subcohort of patients, the associations persisted after additional multivariable adjustment for body mass index and smoking.

CONCLUSIONS

Migraine was associated with increased risks of myocardial infarction, ischaemic stroke, haemorrhagic stroke, venous thromboembolism, and atrial fibrillation or atrial flutter. Migraine may be an important risk factor for most cardiovascular diseases.

Cell therapy of peripheral arterial disease: from experimental findings to clinical trials

The age-adjusted prevalence of peripheral arterial disease in the US population was estimated to approach 12% in 1985, and as the population ages, the overall population having peripheral arterial disease is predicted to rise. The clinical consequences of occlusive peripheral arterial disease include intermittent claudication, that is, pain with walking, and critical limb ischemia (CLI), which includes pain at rest and loss of tissue integrity in the distal limbs, which may ultimately lead to amputation of a portion of the lower extremity. The risk factors for CLI are similar to those linked to coronary artery disease and include advanced age, smoking, diabetes mellitus, hyperlipidemia, and hypertension. The worldwide incidence of CLI was estimated to be 500 to 1000 cases per million people per year in 1991. The prognosis is poor for CLI subjects with advanced limb disease. One study of >400 such subjects in the United Kingdom found that 25% required amputation and 20% (including some subjects who had required amputation) died within 1 year. In the United States, ≈280 lower-limb amputations for ischemic disease are performed per million people each year. The first objective in treating CLI is to increase blood circulation to the affected limb. Theoretically, increased blood flow could be achieved by increasing the number of vessels that supply the ischemic tissue with blood. The use of pharmacological agents to induce new blood vessel growth for the treatment or prevention of pathological clinical conditions has been called therapeutic angiogenesis. Since the identification of the endothelial progenitor cell in 1997 by Asahara and Isner, the field of cell-based therapies for peripheral arterial disease has been in a state of continuous evolution. Here, we review the current state of that field.

Cigarette Smoking, Smoking Cessation, and Long-Term Risk of 3 Major Atherosclerotic Diseases

BACKGROUND

Public statements about the effect of smoking on cardiovascular disease are predominantly based on investigations of coronary heart disease (CHD) and stroke, although smoking is recognized as a strong risk factor for peripheral artery disease (PAD). No study has comprehensively compared the long-term association of cigarette smoking and its cessation with the incidence of 3 major atherosclerotic diseases (PAD, CHD, and stroke).

OBJECTIVES

The aim of this study was to quantify the long-term association of cigarette smoking and its cessation with the incidence of the 3 outcomes.

METHODS

A total of 13,355 participants aged 45 to 64 years in the ARIC (Atherosclerosis Risk In Communities) study without PAD, CHD, or stroke at baseline (1987 to 1989) were included. The associations of smoking parameters (pack-years, duration, intensity, and cessation) with incident PAD were quantified and contrasted with CHD and stroke using Cox models.

RESULTS

Over a median follow-up of 26 years, there were 492 PAD cases, 1,798 CHD cases, and 1,106 stroke cases. A dose-response relationship was identified between pack-years of smoking and 3 outcomes, with the strongest results for PAD. The pattern was consistent when investigating duration and intensity separately. A longer period of smoking cessation was consistently related to lower risk of PAD, CHD, and stroke, but a significantly elevated risk persisted up to 30 years following smoking cessation for PAD and up to 20 years for CHD.

CONCLUSIONS

All smoking measures showed significant associations with 3 major atherosclerotic diseases, with the strongest effect size for incident PAD. The risk due to smoking lasted up to 30 years for PAD and 20 years for CHD. Our results further highlight the importance of smoking prevention and early smoking cessation, and indicate the need for public statements to take PAD into account when acknowledging the impact of smoking on overall cardiovascular health.

Population screening and intervention for vascular disease in Danish men (VIVA): a randomised controlled trial

BACKGROUND

Abdominal aortic aneurysm is the only cardiovascular disease targeted by population screening. In this study, we test the effect of screening and subsequent intervention for abdominal aortic aneurysm, peripheral arterial disease, and hypertension combined.

METHODS

In this randomised controlled trial, we randomly allocated (1:1) all men aged 65-74 years living in the Central Denmark Region to screening for abdominal aortic aneurysm, peripheral arterial disease, and hypertension, or to no screening. We based allocation on computer-generated random numbers from 1 to 100 in blocks of 1067 to 4392, stratified by 19 municipalities. Only the non-screening group and the investigator assessing outcomes were masked. We invited participants who were found to have abdominal aortic aneurysm or peripheral arterial disease back for confirmation and eventual initiation of relevant pharmacological therapy. We further offered participants with abdominal aortic aneurysm annual control or surgical repair. We referred participants with suspected hypertension to their general practitioner. The primary outcome was all-cause mortality, assessed 5 years after randomisation, analysed in all randomly allocated participants except for those who had incorrect person identification numbers. This trial is registered at ClinicalTrials.gov, number NCT00662480.

FINDINGS

Between Oct 8, 2008, and Jan 11, 2011, we randomly allocated 50 156 participants, with 25 078 (50%) each in the screening and non-screening groups. Four (<1%) participants in the screening group were lost to follow-up. After a median follow-up of 4·4 years (IQR 3·9-4·8), 2566 (10·2%) of 25 074 participants in the screening group and 2715 (10·8%) of 25 078 in the non-screening group had died. This finding resulted in a significant hazard ratio of 0·93 (95% CI 0·88-0·98; p=0·01), an absolute risk reduction of 0·006 (0·001-0·011), and a number needed to invite of 169 (89-1811). Incidences of diabetes (3995 per 100 000 person-years in the screening group vs 4129 per 100 000 person-years in the non-screening group), intracerebral haemorrhage (146 vs 140), renal failure (612 vs 649), cancer (3578 vs 3719), or 30 day mortality after cardiovascular surgery (44·57 vs 39·33) did not differ between groups.

INTERPRETATION

The observed reduction of mortality risk from abdominal aortic aneurysm, peripheral arterial disease, and hypertension has never been seen before in the population screening literature and can be linked primarily to initiation of pharmacological therapy. Health policy makers should consider implementing combined screening whether no screening or isolated abdominal aortic aneurysm screening is currently offered.

FUNDING

The 7th European Framework Programme, Central Denmark Region, Viborg Hospital, and the Danish Council for Independent Research.

Lipoprotein(a) and risk of coronary, cerebrovascular, and peripheral artery disease: the EPIC-Norfolk prospective population study

OBJECTIVE

Although the association between circulating levels of lipoprotein(a) [Lp(a)] and risk of coronary artery disease (CAD) and stroke is well established, its role in risk of peripheral arterial disease (PAD) remains unclear. Here, we examine the association between Lp(a) levels and PAD in a large prospective cohort. To contextualize these findings, we also examined the association between Lp(a) levels and risk of stroke and CAD and studied the role of low-density lipoprotein as an effect modifier of Lp(a)-associated cardiovascular risk.

METHODS AND RESULTS

Lp(a) levels were measured in apparently healthy participants in the European Prospective Investigation of Cancer (EPIC)-Norfolk cohort. Cox regression was used to quantify the association between Lp(a) levels and risk of PAD, stroke, and CAD outcomes. During 212 981 person-years at risk, a total of 2365 CAD, 284 ischemic stroke, and 596 PAD events occurred in 18 720 participants. Lp(a) was associated with PAD and CAD outcomes but not with ischemic stroke (hazard ratio per 2.7-fold increase in Lp(a) of 1.37, 95% CI 1.25-1.50, 1.13, 95% CI 1.04-1.22 and 0.91, 95% CI 0.79-1.03, respectively). Low-density lipoprotein cholesterol levels did not modify these associations.

CONCLUSIONS

Lp(a) levels were associated with future PAD and CAD events. The association between Lp(a) and cardiovascular disease was not modified by low-density lipoprotein cholesterol levels.

Bisphenol A and peripheral arterial disease: results from the NHANES

BACKGROUND

Bisphenol A (BPA) is a common chemical used in the manufacture of polycarbonate plastics and epoxy resins, and > 93% of U.S. adults have detectable levels of urinary BPA. Recent animal studies have suggested that BPA exposure may have a role in several mechanisms involved in the development of cardiovascular disease (CVD), including weight gain, insulin resistance, thyroid dysfunction, endothelial dysfunction, and oxidative stress. However, few human studies have examined the association between markers of BPA exposure and CVD. Peripheral arterial disease (PAD) is a subclinical measure of atherosclerotic vascular disease and a strong independent risk factor for CVD and mortality.

OBJECTIVE

We examined the association between urinary BPA levels and PAD in a nationally representative sample of U.S. adults.

METHODS

We analyzed data from 745 participants in the National Health and Nutritional Examination Survey 2003-2004. We estimated associations between urinary BPA levels (in tertiles) and PAD (ankle-brachial index < 0.9, n = 63) using logistic regression models adjusted for potential confounders (age, sex, race/ethnicity, education, smoking, body mass index, diabetes mellitus, hypertension, urinary creatinine, estimated glomerular filtration rate, and serum cholesterol levels).

RESULTS

We observed a significant, positive association between increasing levels of urinary BPA and PAD before and after adjusting for confounders. The multivariable-adjusted odds ratio for PAD associated with the highest versus lowest tertile of urinary BPA was 2.69 (95% confidence interval: 1.02, 7.09; p-trend = 0.01).

CONCLUSIONS

Urinary BPA levels were significantly associated with PAD, independent of traditional CVD risk factors.

Burden of Comorbidities and Functional and Cognitive Impairments in Elderly Patients at the Initial Diagnosis of Heart Failure and Their Impact on Total Mortality: The Cardiovascular Health Study

OBJECTIVES

The purpose of this study was to determine the prevalence of clinically relevant comorbidities and measures of physical and cognitive impairment in elderly persons with incident heart failure (HF).

BACKGROUND

Comorbidities and functional and cognitive impairments are common in the elderly and often associated with greater mortality risk.

METHODS

We examined the prevalence of 9 comorbidities and 4 measures of functional and cognitive impairments in 558 participants from the Cardiovascular Health Study who developed incident HF between 1990 and 2002. Participants were followed prospectively until mid-2008 to determine their mortality risk.

RESULTS

Mean age of participants was 79.2 ± 6.3 years with 52% being men. Sixty percent of participants had ≥3 comorbidities, and only 2.5% had none. Twenty-two percent and 44% of participants had ≥1 activity of daily living (ADL) and ≥1 instrumental activity of daily living (IADL) impaired respectively. Seventeen percent of participants had cognitive impairment (modified mini-mental state exam score <80, scores range between 0 and 100). During follow up, 504 participants died, with 1-, 5-, and 10-year mortality rates of 19%, 56%, and 83%, respectively. In a multivariable-adjusted model, the following were significantly associated with greater total mortality risk: diabetes mellitus (hazard ratio [HR]: 1.64; 95% confidence interval [CI]: 1.33 to 2.03), chronic kidney disease (HR: 1.32; 95% CI: 1.07 to 1.62 for moderate disease; HR: 3.00; 95% CI: 1.82 to 4.95 for severe), cerebrovascular disease (HR: 1.53; 95% CI: 1.22 to 1.92), depression (HR: 1.44; 95% CI: 1.09 to 1.90), functional impairment (HR: 1.30; 95% CI: 1.04 to 1.63 for 1 IADL impaired; HR: 1.49; 95% CI: 1.07 to 2.04 for ≥2 IADL impaired), and cognitive impairment (HR: 1.33; 95% CI: 1.02 to 1.73). Other comorbidities (hypertension, coronary heart disease, peripheral arterial disease, atrial fibrillation, and obstructive airway disease) and measures of functional impairments (ADLs and 15-ft walk time) were not associated with mortality.

CONCLUSIONS

Elderly patients with incident HF have a high burden of comorbidities and functional and cognitive impairments. Some of these conditions are associated with greater mortality risk.

Trimethylamine N-Oxide and Mortality Risk in Patients With Peripheral Artery Disease

BACKGROUND

Production of the proatherogenic metabolite, trimethylamine N-oxide (TMAO), from dietary nutrients by intestinal microbiota enhances atherosclerosis development in animal models and is associated with atherosclerotic coronary artery disease in humans. The utility of studying plasma levels of TMAO to risk stratify in patients with peripheral artery disease (PAD) has not been reported.

METHODS AND RESULTS

We examined the relationship between fasting plasma TMAO and all-cause mortality (5-year), stratified by subtypes of PAD and presence of coronary artery disease in 935 patients with PAD who underwent elective angiography for cardiac evaluation at a tertiary care hospital. Median plasma TMAO was 4.8 μmol/L (interquartile range, 2.9-8.0 μmol/L). Elevated TMAO levels were associated with 2.7-fold increased mortality risk (fourth versus first quartiles, hazard ratio 2.86, 95% CI 1.82-3.97, P<0.001). Following adjustments for traditional risk factors, inflammatory biomarkers, and history of coronary artery disease, the highest TMAO quartile remained predictive of 5-year mortality (adjusted hazard ratio 2.06, 95% CI 1.36-3.11, P<0.001). Similar prognostic value for elevated TMAO was seen for subjects with carotid artery, non-carotid artery, or lower extremity PAD. TMAO provided incremental prognostic value for all-cause mortality (net reclassification index, 40.22%; P<0.001) and improvement in area under receiver operator characteristic curve (65.7% versus 69.4%; P=0.013).

CONCLUSIONS

TMAO, a pro-atherogenic metabolite formed by gut microbes, predicts long-term adverse event risk and incremental prognostic value in patients with PAD. These findings point to the potential for TMAO to help improve selection of high-risk PAD patients with or without significant coronary artery disease, who likely need more aggressive and specific dietary and pharmacologic therapy.

Measures of chronic kidney disease and risk of incident peripheral artery disease: a collaborative meta-analysis of individual participant data

BACKGROUND

Some evidence suggests that chronic kidney disease is a risk factor for lower-extremity peripheral artery disease. We aimed to quantify the independent and joint associations of two measures of chronic kidney disease (estimated glomerular filtration rate [eGFR] and albuminuria) with the incidence of peripheral artery disease.

METHODS

In this collaborative meta-analysis of international cohorts included in the Chronic Kidney Disease Prognosis Consortium (baseline measurements obtained between 1972 and 2014) with baseline measurements of eGFR and albuminuria, at least 1000 participants (this criterion not applied to cohorts exclusively enrolling patients with chronic kidney disease), and at least 50 peripheral artery disease events, we analysed adult participants without peripheral artery disease at baseline at the individual patient level with Cox proportional hazards models to quantify associations of creatinine-based eGFR, urine albumin-to-creatinine ratio (ACR), and dipstick proteinuria with the incidence of peripheral artery disease (including hospitalisation with a diagnosis of peripheral artery disease, intermittent claudication, leg revascularisation, and leg amputation). We assessed discrimination improvement through c-statistics.

FINDINGS

We analysed 817 084 individuals without a history of peripheral artery disease at baseline from 21 cohorts. 18 261 cases of peripheral artery disease were recorded during follow-up across cohorts (median follow-up was 7·4 years [IQR 5·7-8·9], range 2·0-15·8 years across cohorts). Both chronic kidney disease measures were independently associated with the incidence of peripheral artery disease. Compared with an eGFR of 95 mL/min per 1·73 m2, adjusted hazard ratios (HRs) for incident study-specific peripheral artery disease was 1·22 (95% CI 1·14-1·30) at an eGFR of 45 mL/min per 1·73 m2 and 2·06 (1·70-2·48) at an eGFR of 15 mL/min per 1·73 m2. Compared with an ACR of 5 mg/g, the adjusted HR for incident study-specific peripheral artery disease was 1·50 (1·41-1·59) at an ACR of 30 mg/g and 2·28 (2·12-2·44) at an ACR of 300 mg/g. The adjusted HR at an ACR of 300 mg/g versus 5 mg/g was 3·68 (95% CI 3·00-4·52) for leg amputation. eGFR and albuminuria contributed multiplicatively (eg, adjusted HR 5·76 [4·90-6·77] for incident peripheral artery disease and 10·61 [5·70-19·77] for amputation in eGFR <30 mL/min per 1·73 m2 plus ACR ≥300 mg/g or dipstick proteinuria 2+ or higher vs eGFR ≥90 mL/min per 1·73 m2 plus ACR <10 mg/g or dipstick proteinuria negative). Both eGFR and ACR significantly improved peripheral artery disease risk discrimination beyond traditional predictors, with a substantial improvement prediction of amputation with ACR (difference in c-statistic 0·058, 95% CI 0·045-0·070). Patterns were consistent across clinical subgroups.

INTERPRETATION

Even mild-to-moderate chronic kidney disease conferred increased risk of incident peripheral artery disease, with a strong association between albuminuria and amputation. Clinical attention should be paid to the development of peripheral artery disease symptoms and signs in people with any stage of chronic kidney disease.

FUNDING

American Heart Association, US National Kidney Foundation, and US National Institute of Diabetes and Digestive and Kidney Diseases.

Peripheral artery disease and risk of cardiovascular events in patients with coronary artery disease: insights from the Heart and Soul Study

Among patients with coronary artery disease (CAD), those with peripheral artery disease (PAD) have a greater vulnerability to cardiovascular (CV) events than those with CAD alone. In a prospective cohort study of patients with CAD, we evaluated potential mechanisms that might explain the adverse CV outcomes associated with PAD. We performed a prospective cohort study of 1018 patients with stable CAD who were recruited from 2000 to 2002. Incident symptomatic PAD events were adjudicated during a follow-up period of 7.2 ± 2.6 years. We used Cox proportional hazards models to evaluate the association between incident symptomatic PAD events and subsequent risk of CV events or death. Models were adjusted for demographics, traditional risk factors, inflammation, insulin resistance and health behaviors. Among the 1018 patients, 50 patients who did not report a history of PAD at baseline suffered incident symptomatic PAD events during the follow-up period. Those patients had a higher risk of subsequent CV events and death compared to those who did not develop PAD. After adjustment for traditional risk factors, symptomatic PAD events remained associated with a 70% increased risk of subsequent CV events (adjusted HR 1.7; 95% CI 1.0, 2.9; p = 0.04) and an 80% increased risk of death (adjusted HR 1.8; 95% CI 1.2, 2.7; p = 0.006). Inflammatory biomarkers were the strongest risk factor contributing to the excess risk. In a contemporary cohort of patients with CAD, incident symptomatic PAD events were associated with an increased risk for subsequent CV events. The increased vulnerability to CV events was partially explained by shared CV risk factors and inflammation.

New Directions in Therapeutic Angiogenesis and Arteriogenesis in Peripheral Arterial Disease

The prevalence of peripheral arterial disease (PAD) in the United States exceeds 10 million people, and PAD is a significant cause of morbidity and mortality across the globe. PAD is typically caused by atherosclerotic obstructions in the large arteries to the leg(s). The most common clinical consequences of PAD include pain on walking (claudication), impaired functional capacity, pain at rest, and loss of tissue integrity in the distal limbs that may lead to lower extremity amputation. Patients with PAD also have higher than expected rates of myocardial infarction, stroke, and cardiovascular death. Despite advances in surgical and endovascular procedures, revascularization procedures may be suboptimal in relieving symptoms, and some patients with PAD cannot be treated because of comorbid conditions. In some cases, relieving obstructive disease in the large conduit arteries does not assure complete limb salvage because of severe microvascular disease. Despite several decades of investigational efforts, medical therapies to improve perfusion to the distal limb are of limited benefit. Whereas recent studies of anticoagulant (eg, rivaroxaban) and intensive lipid lowering (such as PCSK9 [proprotein convertase subtilisin/kexin type 9] inhibitors) have reduced major cardiovascular and limb events in PAD populations, chronic ischemia of the limb remains largely resistant to medical therapy. Experimental approaches to improve limb outcomes have included the administration of angiogenic cytokines (either as recombinant protein or as gene therapy) as well as cell therapy. Although early angiogenesis and cell therapy studies were promising, these studies lacked sufficient control groups and larger randomized clinical trials have yet to achieve significant benefit. This review will focus on what has been learned to advance medical revascularization for PAD and how that information might lead to novel approaches for therapeutic angiogenesis and arteriogenesis for PAD.