Association between chromosome 9p21 variants and the ankle-brachial index identified by a meta-analysis of 21 genome-wide association studies

Epidemiology and genetic determination of measures of peripheral vascular health in the Long Life Family Study

Peripheral artery disease (PAD) is a major contributor to morbidity in older adults. We aimed to determine genetic and non-genetic determinants of PAD and ankle-brachial index (ABI) in the Long Life Family Study (LLFS). 3006 individuals had ABI assessment, including 1090 probands (mean age 89), 1554 offspring (mean age 60) and 362 spousal controls (mean age 61). Outcomes include minimum of right and left ABIs and PAD (ABI <0.9). Stepwise regression determined independent significant non-genetic correlates of ABI and PAD. Genomewide association and linkage analyses were adjusted for age, sex, study center, significant principal components, and independent predictors. All analyses accounted for familial relatedness. Median ABI was 1.16 and 7.4% had PAD (18.2% probands, 1.0% offspring, 1.9% controls). Correlates of PAD and lower ABI included age, SBP, and creatinine (ABI only); BMI (ABI only), HDL (ABI only) and DBP (PAD only); and antihypertensive use, current smoking, female sex (ABI only), and high school noncompletion (ABI only). Genomewide linkage identified 1 region (15q12-q13) and association identified 3 single nucleotide polymorphisms (rs780213, rs12512857, rs79644420) of interest. In these families, PAD prevalence was low compared to other studies of older adults. We identified four genomic sites that may harbor variants associated with protection from PAD.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

A methodology for gene level omics-WAS integration identifies genes influencing traits associated with cardiovascular risks: the Long Life Family Study

The Long Life Family Study (LLFS) enrolled 4953 participants in 539 pedigrees displaying exceptional longevity. To identify genetic mechanisms that affect cardiovascular risks in the LLFS population, we developed a multi-omics integration pipeline and applied it to 11 traits associated with cardiovascular risks. Using our pipeline, we aggregated gene-level statistics from rare-variant analysis, GWAS, and gene expression-trait association by Correlated Meta-Analysis (CMA). Across all traits, CMA identified 64 significant genes after Bonferroni correction (p ≤ 2.8 × 10-7), 29 of which replicated in the Framingham Heart Study (FHS) cohort. Notably, 20 of the 29 replicated genes do not have a previously known trait-associated variant in the GWAS Catalog within 50 kb. Thirteen modules in Protein-Protein Interaction (PPI) networks are significantly enriched in genes with low meta-analysis p-values for at least one trait, three of which are replicated in the FHS cohort. The functional annotation of genes in these modules showed a significant over-representation of trait-related biological processes including sterol transport, protein-lipid complex remodeling, and immune response regulation. Among major findings, our results suggest a role of triglyceride-associated and mast-cell functional genes FCER1A, MS4A2, GATA2, HDC, and HRH4 in atherosclerosis risks. Our findings also suggest that lower expression of ATG2A, a gene we found to be associated with BMI, may be both a cause and consequence of obesity. Finally, our results suggest that ENPP3 may play an intermediary role in triglyceride-induced inflammation. Our pipeline is freely available and implemented in the Nextflow workflow language, making it easily runnable on any compute platform ( https://nf-co.re/omicsgenetraitassociation ).

Polyvascular Disease: A Narrative Review of Risk Factors, Clinical Outcomes and Treatment

PURPOSE OF REVIEW

Polyvascular disease has a significant global burden and is associated with increased risk of major adverse cardiac events with each additional vascular territory involved. The purpose of this review is to highlight the risk factors, associated outcomes, emerging genetic markers, and evidence for screening and treatment of polyvascular disease.

RECENT FINDINGS

Polyvascular disease is the presence of atherosclerosis in two or more vascular beds. It has a significant global burden, with a prevalence of 30-70% in patients with known atherosclerosis. Patients with polyvascular disease experience elevated rates of cardiovascular death, myocardial infarction and stroke, especially among high-risk subgroups like those with type 2 diabetes mellitus and there is a step-wise increased risk of adverse outcomes with each additional vascular territory involved. Genetic analyses demonstrate that some individuals may carry a genetic predisposition, while others exhibit higher levels of atherogenic lipoproteins and inflammatory markers. Routine screening for asymptomatic disease is not currently recommended by major cardiovascular societies unless patients are high-risk. While there are no established protocols for escalating treatment, existing guidelines advocate for lipid-lowering therapy. Additionally, recent studies have demonstrated benefit from antithrombotic agents, such as P2Y12 inhibitors and low-dose anticoagulation, but the optimal timing and dosage of these agents has not been established, and the ischemic benefit must be balanced against the increased risk of bleeding in the polyvascular population. Due to the high prevalence and risks associated with polyvascular disease, early identification and treatment intensification are crucial to reduce disease progression. Future research is needed to develop screening protocols and determine the optimal timing and dosing of therapy to prevent ischemic events.

Multi-omics Integration Identifies Genes Influencing Traits Associated with Cardiovascular Risks: The Long Life Family Study

The Long Life Family Study (LLFS) enrolled 4,953 participants in 539 pedigrees displaying exceptional longevity. To identify genetic mechanisms that affect cardiovascular risks in the LLFS population, we developed a multi-omics integration pipeline and applied it to 11 traits associated with cardiovascular risks. Using our pipeline, we aggregated gene-level statistics from rare-variant analysis, GWAS, and gene expression-trait association by Correlated Meta-Analysis (CMA). Across all traits, CMA identified 64 significant genes after Bonferroni correction (p ≤ 2.8×10-7), 29 of which replicated in the Framingham Heart Study (FHS) cohort. Notably, 20 of the 29 replicated genes do not have a previously known trait-associated variant in the GWAS Catalog within 50 kb. Thirteen modules in Protein-Protein Interaction (PPI) networks are significantly enriched in genes with low meta-analysis p-values for at least one trait, three of which are replicated in the FHS cohort. The functional annotation of genes in these modules showed a significant over-representation of trait-related biological processes including sterol transport, protein-lipid complex remodeling, and immune response regulation. Among major findings, our results suggest a role of triglyceride-associated and mast-cell functional genes FCER1A, MS4A2, GATA2, HDC, and HRH4 in atherosclerosis risks. Our findings also suggest that lower expression of ATG2A, a gene we found to be associated with BMI, may be both a cause and consequence of obesity. Finally, our results suggest that ENPP3 may play an intermediary role in triglyceride-induced inflammation. Our pipeline is freely available and implemented in the Nextflow workflow language, making it easily runnable on any compute platform (https://nf-co.re/omicsgenetraitassociation).

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Genetic Variants at the 9p21.3 Locus Are Associated with Risk for Non-Compressible Artery Disease: Results from the ARTPER Study

Peripheral artery disease (PAD) and non-compressible artery disease (NCAD) constitute predictors of subclinical atherosclerosis easily assessed through the ankle brachial index (ABI). Although both diseases show substantial genetic influences, few genetic association studies have focused on the ABI and PAD, and none have focused on NCAD. To overcome these limitations, we assessed the role of several candidate genes on the ABI, both in its continuous distribution and in the clinical manifestations associated to its extreme values: PAD and NCAD. We examined 13 candidate genomic regions in 1606 participants from the ARTPER study, a prospective population-based cohort, with the ABI assessed through ultrasonography. Association analyses were conducted independently for individuals with PAD (ABI < 0.9) or with NCAD (ABI > 1.4) vs. healthy participants. After including potential covariates and correction for multiple testing, minor alleles in the genetic markers rs10757278 and rs1333049, both in the 9p21.3 region, were significantly associated with a decreased risk of NCAD. Associations with the ABI showed limited support to these results. No significant associations were detected for PAD. The locus 9p21.3 constitutes the first genetic locus associated with NCAD, an assessment of subclinical atherosclerosis feasible for implementation in primary healthcare settings that has been systematically neglected from genetic studies.

A two-sample Mendelian randomization study of atherosclerosis and dementia

The causality between atherosclerosis and dementia remains unclear. This study aimed to explore the causal effect of atherosclerosis related indicators on dementia risk based on two-sample Mendelian randomization (MR) using summary statistics of genome-wide association studies (GWASs). The inverse variance weighted (IVW) method was performed as the main analysis, supplemented by different sensitivity analyses. Suggestive evidence indicated that peripheral arterial disease (PAD) (odds ratio (OR): 0.864, 95% confidence interval (CI): 0.797-0.937), coronary atherosclerosis (CoAS) (OR: 0.927, 95% CI: 0.860-0.998) and atherosclerosis, excluding cerebral, coronary, and PAD (ATHSCLE) (OR: 0.812, 95% CI: 0.725-0.909) were inversely associated with the risk of AD. The sensitivity analysis confirmed a suggestive reverse effect of ATHSCLE on the risk of frontotemporal dementia (FTD) (OR, 0.812, 95% CI, 0.725-0.909). Findings provide suggestive evidence that PAD, CoAS, and ATHSCLE might be associated with the risk of AD or FTD, which requires further exploration in larger samples.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Inflammatory and Prothrombotic Biomarkers, DNA Polymorphisms, MicroRNAs and Personalized Medicine for Patients with Peripheral Arterial Disease

Classical risk factors play a major role in the initiation and development of atherosclerosis. However, the estimation of risk for cardiovascular events based only on risk factors is often insufficient. Efforts have been made to identify biomarkers that indicate ongoing atherosclerosis. Among important circulating biomarkers associated with peripheral arterial disease (PAD) are inflammatory markers which are determined by the expression of different genes and epigenetic processes. Among these proinflammatory molecules, interleukin-6, C-reactive protein, several adhesion molecules, CD40 ligand, osteoprotegerin and others are associated with the presence and progression of PAD. Additionally, several circulating prothrombotic markers have a predictive value in PAD. Genetic polymorphisms significantly, albeit moderately, affect risk factors for PAD via altered lipoprotein metabolism, diabetes, arterial hypertension, smoking, inflammation and thrombosis. However, most of the risk variants for PAD are located in noncoding regions of the genome and their influence on gene expression remains to be explored. MicroRNAs (miRNAs) are single-stranded, noncoding RNAs that modulate gene expression at the post-transcriptional level. Patterns of miRNA expression, to some extent, vary in different atherosclerotic cardiovascular diseases. miRNAs appear to be useful in the detection of PAD and the prediction of progression and revascularization outcomes. In conclusion, taking into account one’s predisposition to PAD, i.e., DNA polymorphisms and miRNAs, together with circulating inflammatory and coagulation markers, holds promise for more accurate prediction models and personalized therapeutic options.

The Genetic Architecture of the Etiology of Lower Extremity Peripheral Artery Disease: Current Knowledge and Future Challenges in the Era of Genomic Medicine

Lower extremity artery disease (LEAD), caused by atherosclerotic obstruction of the arteries of the lower limb extremities, has exhibited an increase in mortality and morbidity worldwide. The phenotypic variability of LEAD is correlated with its complex, multifactorial etiology. In addition to traditional risk factors, it has been shown that the interaction between genetic factors (epistasis) or between genes and the environment potentially have an independent role in the development and progression of LEAD. In recent years, progress has been made in identifying genetic variants associated with LEAD, by Genome-Wide Association Studies (GWAS), Whole Exome Sequencing (WES) studies, and epigenetic profiling. The aim of this review is to present the current knowledge about the genetic factors involved in the etiopathogenic mechanisms of LEAD, as well as possible directions for future research. We analyzed data from the literature, starting with candidate gene-based association studies, and then continuing with extensive association studies, such as GWAS and WES. The results of these studies showed that the genetic architecture of LEAD is extremely heterogeneous. In the future, the identification of new genetic factors will allow for the development of targeted molecular therapies, and the use of polygenic risk scores (PRS) to identify individuals at an increased risk of LEAD will allow for early prophylactic measures and personalized therapy to improve their prognosis.

Development of a polygenic risk score to improve detection of peripheral artery disease

INTRODUCTION

Peripheral artery disease (PAD) is a major cause of cardiovascular morbidity and mortality, yet timely diagnosis is elusive. Larger genome-wide association studies (GWAS) have now provided the ability to evaluate whether genetic data, in the form of genome-wide polygenic risk scores (PRS), can help improve our ability to identify patients at high risk of having PAD.

METHODS

Using summary statistic data from the largest PAD GWAS from the Million Veteran Program, we developed PRSs with genome data from UK Biobank. We then evaluated the clinical utility of adding the best-performing PRS to a PAD clinical risk score.

RESULTS

A total of 487,320 participants (5759 PAD cases) were included in our final genetic analysis. Compared to participants in the lowest 10% of PRS, those in the highest decile had 3.1 higher odds of having PAD (95% CI, 3.06-3.21). Additionally, a PAD PRS was associated with increased risk of having coronary artery disease, congestive heart failure, and cerebrovascular disease. The PRS significantly improved a clinical risk model (Net Reclassification Index = 0.07, p < 0.001), with most of the performance seen in downgrading risk of controls. Combining clinical and genetic data to detect risk of PAD resulted in a model with an area under the curve of 0.76 (95% CI, 0.75-0.77).

CONCLUSION

We demonstrate that a genome-wide PRS can discriminate risk of PAD and other cardiovascular diseases. Adding a PAD PRS to clinical risk models may help improve detection of prevalent, but undiagnosed disease.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Unsupervised Learning for Automated Detection of Coronary Artery Disease Subgroups

Background The promise of precision population health includes the ability to use robust patient data to tailor prevention and care to specific groups. Advanced analytics may allow for automated detection of clinically informative subgroups that account for clinical, genetic, and environmental variability. This study sought to evaluate whether unsupervised machine learning approaches could interpret heterogeneous and missing clinical data to discover clinically important coronary artery disease subgroups. Methods and Results The Genetic Determinants of Peripheral Arterial Disease study is a prospective cohort that includes individuals with newly diagnosed and/or symptomatic coronary artery disease. We applied generalized low rank modeling and K-means cluster analysis using 155 phenotypic and genetic variables from 1329 participants. Cox proportional hazard models were used to examine associations between clusters and major adverse cardiovascular and cerebrovascular events and all-cause mortality. We then compared performance of risk stratification based on clusters and the American College of Cardiology/American Heart Association pooled cohort equations. Unsupervised analysis identified 4 phenotypically and prognostically distinct clusters. All-cause mortality was highest in cluster 1 (oldest/most comorbid; 26%), whereas major adverse cardiovascular and cerebrovascular event rates were highest in cluster 2 (youngest/multiethnic; 41%). Cluster 4 (middle-aged/healthiest behaviors) experienced more incident major adverse cardiovascular and cerebrovascular events (30%) than cluster 3 (middle-aged/lowest medication adherence; 23%), despite apparently similar risk factor and lifestyle profiles. In comparison with the pooled cohort equations, cluster membership was more informative for risk assessment of myocardial infarction, stroke, and mortality. Conclusions Unsupervised clustering identified 4 unique coronary artery disease subgroups with distinct clinical trajectories. Flexible unsupervised machine learning algorithms offer the ability to meaningfully process heterogeneous patient data and provide sharper insights into disease characterization and risk assessment. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00380185.

Medial Arterial Calcification: JACC State-of-the-Art Review

Medial arterial calcification (MAC) is a chronic systemic vascular disorder distinct from atherosclerosis that is frequently but not always associated with diabetes mellitus, chronic kidney disease, and aging. MAC is also a part of more complex phenotypes in numerous less common diseases. The hallmarks of MAC include disseminated and progressive precipitation of calcium phosphate within the medial layer, a prolonged and clinically silent course, and compromise of hemodynamics associated with chronic limb-threatening ischemia. MAC increases the risk of complications during vascular interventions and mitigates their outcomes. With the exception of rare monogenetic defects affecting adenosine triphosphate metabolism, MAC pathogenesis remains unknown, and causal therapy is not available. Implementation of genetics and omics-based approaches in research recognizing the critical importance of calcium phosphate thermodynamics holds promise to unravel MAC molecular pathogenesis and to provide guidance for therapy. The current state of knowledge concerning MAC is reviewed, and future perspectives are outlined.

Genetic Determinants of Peripheral Artery Disease

Peripheral artery disease-atherosclerosis of the abdominal aorta and lower extremity vascular bed-is a complex disease with both environmental and genetic determinants. Unmitigated disease is associated with major functional decline and can lead to chronic limb-threatening ischemia, amputation, and increased mortality. Over the last 10 years, major advances have been made in identifying the genetic basis of this common, complex disease. In this review, we provide an overview of the primary types of genetic analyses performed for peripheral artery disease, including heritability and linkage studies, and more recently biobank-based genome-wide association studies. Looking forward, we highlight areas of future study including efforts to identify causal peripheral artery disease genes, rare variant and structural variant analyses using whole-exome and whole-genome sequencing data, and the need to include individuals of diverse genetic ancestries.

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.

Gene Expression Signature in Patients With Symptomatic Peripheral Artery Disease

[Figure: see text].

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Epigenetic loci for blood pressure are associated with hypertensive target organ damage in older African Americans from the genetic epidemiology network of Arteriopathy (GENOA) study

BACKGROUND

Hypertension is a major modifiable risk factor for arteriosclerosis that can lead to target organ damage (TOD) of heart, kidneys, and peripheral arteries. A recent epigenome-wide association study for blood pressure (BP) identified 13 CpG sites, but it is not known whether DNA methylation at these sites is also associated with TOD.

METHODS

In 1218 African Americans from the Genetic Epidemiology Network of Arteriopathy (GENOA) study, a cohort of hypertensive sibships, we evaluated the associations between methylation at these 13 CpG sites measured in peripheral blood leukocytes and five TOD traits assessed approximately 5 years later.

RESULTS

Ten significant associations were found after adjustment for age, sex, blood cell counts, time difference between CpG and TOD measurement, and 10 genetic principal components (FDR q < 0.1): two with estimated glomerular filtration rate (eGFR, cg06690548, cg10601624), six with urinary albumin-to-creatinine ratio (UACR, cg16246545, cg14476101, cg19693031, cg06690548, cg00574958, cg22304262), and two with left ventricular mass indexed to height (LVMI, cg19693031, cg00574958). All associations with eGFR and four associations with UACR remained significant after further adjustment for body mass index (BMI), smoking status, and diabetes. We also found significant interactions between cg06690548 and BMI on UACR, and between 3 CpG sites (cg19693031, cg14476101, and cg06690548) and diabetes on UACR (FDR q < 0.1). Mediation analysis showed that 4.7% to 38.1% of the relationship between two CpG sites (cg19693031 and cg00574958) and two TOD measures (UACR and LVMI) was mediated by blood pressure (Bonferroni-corrected P < 0.05). Mendelian randomization analysis suggests that methylation at two sites (cg16246545 and cg14476101) in PHGDH may causally influence UACR.

CONCLUSIONS

In conclusion, we found compelling evidence for associations between arteriosclerotic traits of kidney and heart and previously identified blood pressure-associated DNA methylation sites. This study may lend insight into the role of DNA methylation in pathological mechanisms underlying target organ damage from hypertension.

The Long Non-coding Road to Atherosclerosis

Purpose of Review

To summarize recent insights into long non-coding RNAs (lncRNAs) involved in atherosclerosis. Because atherosclerosis is the main underlying pathology of cardiovascular diseases (CVD), the world’s deadliest disease, finding novel therapeutic strategies is of high interest.

Recent Findings

LncRNAs can bind to proteins, DNA, and RNA regulating disease initiation and plaque growth as well as plaque stability in different cell types such as endothelial cells (ECs), vascular smooth muscle cells (VSMCs), and macrophages. A number of lncRNAs have been implicated in cholesterol homeostasis and foam cell formation such as LASER, LeXis, and CHROME. Among others, MANTIS, lncRNA-CCL2, and MALAT1 were shown to be involved in vascular inflammation. Further regulations include, but are not limited to, DNA damage response in ECs, phenotypic switch of VSMCs, and various cell death mechanisms. Interestingly, some lncRNAs are closely correlated with response to statin treatment, such as NEXN-AS1 or LASER. Additionally, some lncRNAs may serve as CVD biomarkers.

Summary

LncRNAs are a potential novel therapeutic target to treat CVD, but research of lncRNA in atherosclerosis is still in its infancy. With increasing knowledge of the complex and diverse regulations of lncRNAs in the heterogeneous environment of atherosclerotic plaques, lncRNAs hold promise for their clinical translation in the near future.

Targeted Sequencing Study to Uncover Shared Genetic Susceptibility Between Peripheral Artery Disease and Coronary Heart Disease-Brief Report

Objective- It is unclear to what extent genetic susceptibility variants are shared between peripheral artery disease (PAD) and coronary heart disease (CHD), both manifestations of atherosclerotic vascular disease. We investigated whether common and low-frequency/rare variants in loci associated with CHD are also associated with PAD. Approach and Results- Targeted sequencing of 41 genomic regions associated with CHD in genome-wide association studies was performed in 1749 PAD cases (65±11 years, 61% men) and 1855 controls (60±11 years, 56% men) of European ancestry. PAD cases had a resting/postexercise ankle-brachial index ≤0.9, or history of lower extremity revascularization; controls had no history of PAD. We tested the association of common (defined as minor allele frequency ≥5%) variants with PAD assuming an additive genetic model with adjustment for age and sex. To identify low-frequency/rare variants (minor allele frequency <5%) associated with PAD, we conducted gene-level analyses using sequence kernel association test and permutation test. After Bonferroni correction, we found common variants in SH2B3, ABO, and ZEB2 to be associated with PAD ( P<4.5×10^-5). At the gene level, the strongest associations were for LPL and SH2B3. Conclusions- Targeted sequencing of 41 genomic regions associated with CHD revealed several common variants/genes to be associated with PAD, highlighting the basis of shared genetic susceptibility between CHD and PAD.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Noncoding RNAs in Critical Limb Ischemia

Peripheral artery disease, caused by chronic arterial occlusion of the lower extremities, affects over 200 million people worldwide. Peripheral artery disease can progress into critical limb ischemia (CLI), its more severe manifestation, which is associated with higher risk of limb amputation and cardiovascular death. Aiming to improve tissue perfusion, therapeutic angiogenesis held promise to improve ischemic limbs using delivery of growth factors but has not successfully translated into benefits for patients. Moreover, accumulating studies suggest that impaired downstream signaling of these growth factors (or angiogenic resistance) may significantly contribute to CLI, particularly under harsh environments, such as diabetes mellitus. Noncoding RNAs are essential regulators of gene expression that control a range of pathophysiologies relevant to CLI, including angiogenesis/arteriogenesis, hypoxia, inflammation, stem/progenitor cells, and diabetes mellitus. In this review, we summarize the role of noncoding RNAs, including microRNAs and long noncoding RNAs, as functional mediators or biomarkers in the pathophysiology of CLI. A better understanding of these ncRNAs in CLI may provide opportunities for new targets in the prevention, diagnosis, and therapeutic management of this disabling disease state.

Intrinsic and extrinsic epigenetic age acceleration are associated with hypertensive target organ damage in older African Americans

Background

Epigenetic age acceleration, a measure of biological aging based on DNA methylation, is associated with cardiovascular mortality. However, little is known about its relationship with hypertensive target organ damage to the heart, kidneys, brain, and peripheral arteries.

Methods

We investigated associations between intrinsic (IEAA) or extrinsic (EEAA) epigenetic age acceleration, blood pressure, and six types of organ damage in a primarily hypertensive cohort of 1390 African Americans from the Genetic Epidemiology Network of Arteriopathy (GENOA) study. DNA methylation from peripheral blood leukocytes was collected at baseline (1996–2000), and measures of target organ damage were assessed in a follow-up visit (2000–2004). Linear regression with generalized estimating equations was used to test for associations between epigenetic age acceleration and target organ damage, as well as effect modification of epigenetic age by blood pressure or sex. Sequential Oligogenic Linkage Analysis Routines (SOLAR) was used to test for evidence of shared genetic and/or environmental effects between epigenetic age acceleration and organ damage pairs that were significantly associated.

Results

After adjustment for sex, chronological age, and time between methylation and organ damage measures, higher IEAA was associated with higher urine albumin to creatinine ratio (UACR, p = 0.004), relative wall thickness (RWT, p = 0.022), and left ventricular mass index (LVMI, p = 0.007), and with lower ankle-brachial index (ABI, p = 0.014). EEAA was associated with higher LVMI (p = 0.005). Target organ damage associations for all but IEAA with LVMI remained significant after further adjustment for blood pressure and antihypertensive use (p < 0.05). Further adjustment for diabetes attenuated the IEAA associations with UACR and RWT, and adjustment for smoking attenuated the IEAA association with ABI. No effect modification by age or sex was observed.

Conclusions

Measures of epigenetic age acceleration may help to better characterize the functional mechanisms underlying organ damage from cellular aging and/or hypertension. These measures may act as subclinical biomarkers for damage to the kidney, heart, and peripheral vasculature; however more research is needed to determine whether these relationships remain independent of lifestyle factors and comorbidities.

Using the epidemiology of critical limb ischemia to estimate the number of patients amenable to endovascular therapy

Critical limb ischemia represents the advanced stage of peripheral artery disease, a health problem with increasing prevalence. Critical limb ischemia is associated with significant mortality, limb loss, pain, and diminished health-related quality of life. Public awareness and early diagnosis are necessary for an effective treatment with early risk factor modification, smoking cessation, and exercise therapy. Herein, we present an overview of the epidemiology as well as the clinical stages of the disease, and estimate that there are 6.5 million patients with critical limb ischemia in the US, Europe, and Japan based on global population-based studies. At least 75% of these patients, accounting for approximately 4.8 million patients, are amenable to endovascular therapy.

Variants Associated with the Ankle Brachial Index Differ by Hispanic/Latino Ethnic Group: a genome-wide association study in the Hispanic Community Health Study/Study of Latinos

Lower extremity peripheral artery disease (PAD) burden differs by race/ethnicity. Although familial aggregation and heritability studies suggest a genetic basis, little is known about the genetic susceptibility to PAD, especially in non-European descent populations. Genome-wide association studies (GWAS) of the ankle brachial index (ABI) and PAD (defined as an ABI < 0.90) have not been conducted in Hispanics/Latinos. We performed a GWAS of PAD and the ABI in 7,589 participants aged >45 years from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). We also performed GWAS for ABI stratified by Hispanic/Latino ethnic subgroups: Central American, Mexican, and South American (Mainland group), and Cuban, Dominican, and Puerto Rican (Caribbean group). We detected two genome-wide significant associations for the ABI in COMMD10 in Puerto Ricans, and at SYBU in the Caribbean group. The lead SNP rs4466200 in the COMMD10 gene had a replication p = 0.02 for the ABI in Multi-Ethnic Study of Atherosclerosis (MESA) African Americans, but it did not replicate in African Americans from the Cardiovascular Health Study (CHS). In a regional look-up, a nearby SNP rs12520838 had Bonferroni adjusted p = 0.05 (unadjusted p = 7.5 × 10-5) for PAD in MESA Hispanics. Among three suggestive associations (p < 10-7) in subgroup-specific analyses, DMD on chromosome X, identified in Central Americans, replicated in MESA Hispanics (p = 2.2 × 10-4). None of the previously reported ABI and PAD associations in whites generalized to Hispanics/Latinos.

Genome-wide association study of peripheral artery disease in the Million Veteran Program

Peripheral artery disease (PAD) is a leading cause of cardiovascular morbidity and mortality¹; however, the extent to which genetic factors increase risk for PAD is largely unknown. Using electronic health record data, we performed a genome-wide association study in the Million Veteran Program testing ~32 million DNA sequence variants with PAD (31,307 cases and 211,753 controls) across veterans of European, African, and Hispanic ancestry. The results were replicated in an independent sample of 5,117 PAD cases and 389,291 controls from UK Biobank. We identified 19 PAD loci, 18 of which have not been previously reported. 11 of the 19 loci were associated with disease in three vascular beds (coronary, cerebral, peripheral), including LDLR, LPL, and LPA, suggesting that therapeutic modulation of LDL cholesterol, the LPL pathway or circulating lipoprotein(a) may be efficacious for multiple atherosclerotic disease phenotypes. Conversely, 4 of the variants appeared to be specific for PAD, including F5 p.R506Q, highlighting the pathogenic role of thrombosis in the peripheral vascular bed and providing genetic support for Factor Xa inhibition as a therapeutic strategy for PAD. Our results highlight mechanistic similarities and differences among coronary, cerebral, and peripheral atherosclerosis and provide therapeutic insights.

Searching for the Genetic Determinants of Peripheral Arterial Disease: A Review of the Literature and Future Directions

Peripheral arterial disease (PAD) is a significant but under-recognized disease that is poorly understood despite population-scale genetic studies. To address this morbid disease, clinicians need additional tools to identify, prevent, and treat patients at risk for PAD. Genetic studies of coronary artery disease have yielded promising results for clinical application, which have thus far been lacking in PAD. In this article, we review recent findings, discuss limitations, and propose future directions of genomic study and clinical application. However, despite many studies, we still lack definitive genetic markers for PAD. This can be attributed to the heterogeneity of PAD's pathogenesis and clinical manifestations, as well as inconsistencies in study methodologies, limitations of current genetic assessment techniques, incompletely comprehended molecular pathophysiology, and confounding generalized atherosclerotic risk factors. The goals of this review are to evaluate the limitations of our current genetic knowledge of PAD and to propose approaches to expedite the identification of valuable markers of PAD.

Long Noncoding RNA ANRIL: Lnc-ing Genetic Variation at the Chromosome 9p21 Locus to Molecular Mechanisms of Atherosclerosis

Ever since the first genome-wide association studies (GWAS) on coronary artery disease (CAD), the Chr9p21 risk locus has emerged as a top signal in GWAS of atherosclerotic cardiovascular disease, including stroke and peripheral artery disease. The CAD risk SNPs on Chr9p21 lie within a stretch of 58 kilobases of non-protein-coding DNA, containing the gene body of the long noncoding RNA (lncRNA) antisense non coding RNA in the INK4 locus (ANRIL). How risk is affected by the Chr9p21 locus in molecular detail is a matter of ongoing research. Here we will review recent advances in the understanding that ANRIL serves as a key risk effector molecule of atherogenesis at the locus. One focus of this review is the shift in understanding that genetic variation at Chr9p21 not only affects the abundance of ANRIL, and in some cases expression of the adjacent CDKN2A/B tumor suppressors, but also impacts ANRIL splicing, such that 3′-5′-linked circular noncoding ANRIL RNA species are produced. We describe how the balance of linear and circular ANRIL RNA, determined by the Chr9p21 genotype, regulates molecular pathways and cellular functions involved in atherogenesis. We end with an outlook on how manipulating circular ANRIL abundance may be exploited for therapeutic purposes.

Association between 1p13 polymorphisms and peripheral arterial disease in a Chinese population with diabetes

AIMS/INTRODUCTION

Variants on chromosome 1p13 have been associated with coronary artery disease and acute myocardial infarction risk in different ethnic groups. The present study aimed to investigate the association between 1p13 polymorphisms and the development of peripheral artery disease (PAD) in a Chinese population with type 2 diabetes mellitus.

MATERIALS AND METHODS

1p13 polymorphisms, rs599839, rs646776 and rs12740374, were assessed in a cohort of 882 type 2 diabetes mellitus patients including 440 type 2 diabetes mellitus patients with PAD (DM + PAD group) and 442 patients without PAD (DM group). Genotyping was carried out using TaqMan assay.

RESULTS

Compared with the DM group, the frequencies of the minor G allele of both rs599839 and rs646776 and the minor T allele of rs12740374 decreased (P = 0.013, P = 0.019 and P = 0.005, respectively), and the frequencies of rs599839 AG + GG, rs646776 AG + GG and rs12740374 CT+TT genotypes were statistically significantly decreased as well (P = 0.017, P = 0.011 and P = 0.007, respectively) in the dominant model in the DM + PAD group than in the DM group. Multivariate unconditional logistic regression analyses adjusted for age, glycated hemoglobin, triglyceride, low-density lipoprotein cholesterol, smoking, hypertension, diabetes duration, coronary heart disease and cerebral infarction showed that the genotypic distribution of rs599839 AG + GG, rs646776 AG + GG and rs12740374 CT + TT remained statistically different between the DM and DM + PAD group (P = 0.014, P = 0.003 and P = 0.004, respectively). The frequencies of haplotype GGT were statistically significantly different between groups (P = 0.08).

CONCLUSIONS

The present study strongly supports that genotypes of rs599839, rs646776 and rs12740374 on 1p13 are protective factors for diabetic PAD in a Chinese population. Haplotype GGT generated by rs599839, rs646776 and rs12740374 might also decrease the risk of the disease.

Risk allele of gene variant rs6584389 is associated with increased intima-media thickness in patients with type 2 diabetes

BACKGROUND

Genome-wide association studies identified several gene variants associated with peripheral arterial disease (PAD). Among them, rs6584389 A>C was significantly associated with PAD defined by decreased ankle-brachial index (ABI). The aim of this study was to investigate whether the rs6584389 variant is also associated with the earlier stages of atherosclerosis assessed by intima-media thickness (IMT) or pulse-wave velocity (PWV) in clinically asymptomatic subjects with type 2 diabetes (T2DM), a group of patients with a high cardiovascular risk.

PATIENTS AND METHODS

In total, 111 patients with T2DM (56 females, 55 males) with a mean age 63.0 ± 9.1 years were consecutively included in the study. IMT was measured by ultrasound using 7 MHz linear transducer. PWV was measured using a piezoelectric method. Genotyping for rs6584389 was performed by PCR-HRMA method.

RESULTS

The carriers of the risk C-allele of rs6584389 variant had significantly higher mean left-side IMT (AA: 0.67 ± 0.12, AC 0.77 ± 0.21, CC 0.78 ± 0.22 mm; p = 0.04). In multiple linear regression analysis, rs6586389 genotype was significantly associated with all measured IMT parameters. The presence of each risk C-allele predicted an increase in left-side IMT by 0.056 mm (p = 0.017), right-side IMT by 0.053 mm (p = 0.039), average IMT by 0.054 mm (p = 0.023), and maximal IMT by 0.058 mm (p = 0.021). Age and HbA1c levels were also significantly associated with increased IMT in all multivariate models.

CONCLUSIONS

Gene variant rs6584389 A>C near to PAX2 gene was associated with increased carotid IMT in patients with type 2 diabetes independently of the other main risk factors for atherosclerosis.

Peripheral Arterial Disease Genetics: Progress to Date and Challenges Ahead

PURPOSE OF REVIEW

In this paper, we review the progress made thus far in research related to the genetics of peripheral arterial disease (PAD) by detailing efforts to date in heritability, linkage analyses, and candidate gene studies. We further summarize more contemporary genome-wide association studies (GWAS) and epigenetic studies of PAD. Finally, we review current challenges and future avenues of advanced research in PAD genetics including whole genome sequencing studies.

RECENT FINDINGS

Studies have estimated the heritability of PAD to be moderate, though the contribution to this heritability that is independent of traditional cardiovascular risk factors remains unclear. Recent efforts have identified SNPs associated with PAD in GWAS analyses, but these have yet to be replicated in independent studies. Much remains to be discovered in the field of PAD genetics. An improved understanding of the genetic foundation for PAD will allow for earlier diagnosis of disease and a more complete pathophysiological understanding of the mechanisms of the disease leading to novel therapeutic interventions. Future avenues for success will likely arise from very large-scale GWAS, whole genome sequencing, and epigenetic studies involving very well-characterized cohorts.

The Rotterdam Study: 2018 update on objectives, design and main results

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1500 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

A GDF15 3' UTR variant, rs1054564, results in allele-specific translational repression of GDF15 by hsa-miR-1233-3p

Growth differentiation factor 15 (GDF15) is a strong predictor of cardiovascular events and mortality in individuals with or without cardiovascular diseases. Single nucleotide polymorphisms (SNPs) in microRNA (miRNA) target sites, also known as miRSNPs, are known to enhance or weaken miRNA-mRNA interactions and have been linked to diseases such as cardiovascular disease and cancer. In this study, we aimed to elucidate the functional significance of the miRSNP rs1054564 in regulating GDF15 levels. Two rs1054564-containing binding sites for hsa-miR-873-5p and hsa-miR-1233-3p were identified in the 3′ untranslated region (UTR) of the GDF15 transcript using bioinformatics tools. Their activities were further characterized by in vitro reporter assays. Bioinformatics prediction suggested that miRNA binding sites harboring the rs1054564-G allele had lower free energies than those with the C allele and therefore were better targets with higher affinities for both hsa-miR-873-5p and hsa-miR-1233-3p. Reporter assays showed that luciferase activity was significantly decreased by rs1054564-G-containing 3′ UTRs for both miRNAs (P < 0.05) and was restored by miRNA inhibitors. Comparing the fold suppression of the two miRNAs, only that of hsa-miR-1233-3p showed significant changes between the rs1054564-G- and C-containing 3′ UTRs (P = 0.034). In addition, western blots showed that transfection of both miRNA mimics significantly decreased endogenous GDF15 expression in a melanoma cell line (P < 0.05). Taken together, our findings demonstrate that GDF15 is a target of hsa-miR-873-5p and hsa-miR-1233-3p and that the rs1054564-C allele partially abolishes hsa-miR-1233-3p-mediated translational suppression of GDF15. These results suggest that rs1054564 confers allele-specific translational repression of GDF15 via hsa-miR-1233-3p. Our work thus provides biological insight into the previously reported clinical association between rs1054564 and plasma GDF15 levels.

Gene-based therapies in patients with critical limb ischemia

Critical limb ischemia (CLI) constitutes a life-limiting and life-threatening disease. Revascularization, either endovascular or surgical, remains the best treatment option accompanied by medication and risk factor modification. Patients unable to undergo revascularization, referred as 'no-option patients', have been the center of interest the last few years, subjected to treatment therapies based on proteins (mainly growth factors) involved in angiogenesis via gene delivery to the ischemic tissue. Areas covered: This review focuses on these growth factors, gives an update of the studies available, discusses the possible problems that influence outcomes and describes future perspectives including possible new technologies that will improve them. Additionally, the authors attempt to place therapeutic angiogenesis to the bigger frame of tailored therapy in CLI. Expert opinion: Although encouraging in the beginning, growth factor therapy results have been equivocal and inconclusive. And while it would be misleading to approach gene therapy as panacea, its effect on the micro-circulatory level activating angiogenesis and arteriogenesis could act as an important adjunct in personalized treatment.

Clinical worthlessness of genetic prediction of common forms of diabetes mellitus and related chronic complications: A position statement of the Italian Society of Diabetology

AIM

We are currently facing several attempts aimed at marketing genetic data for predicting multifactorial diseases, among which diabetes mellitus is one of the more prevalent. The present document primarily aims at providing to practicing physicians a summary of available data regarding the role of genetic information in predicting diabetes and its chronic complications.

DATA SYNTHESIS

Firstly, general information about characteristics and performance of risk prediction tools will be presented in order to help clinicians to get acquainted with basic methodological information related to the subject at issue. Then, as far as type 1 diabetes is concerned, available data indicate that genetic information and counseling may be useful only in families with many affected individuals. However, since no disease prevention is possible, the utility of predicting this form of diabetes is at question. In the case of type 2 diabetes, available data really question the utility of adding genetic information on top of well performing, easy available and inexpensive non-genetic markers. Finally, the possibility of using the few available genetic data on diabetic complications for improving our ability to predict them will also be presented and discussed. For cardiovascular complication, the addition of genetic information to models based on clinical features does not translate in a substantial improvement in risk discrimination. For all other diabetic complications genetic information are currently very poor and cannot, therefore, be used for improving risk stratification.

CONCLUSIONS

In all, nowadays the use of genetic testing for predicting diabetes and its chronic complications is definitively of little value in clinical practice.

Heterozygote Advantage of the rs3794624 Polymorphism in CYBA for Resistance to Tuberculosis in Two Chinese Populations

Phagocyte Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase complex is a key enzyme that catalyzes the production of reactive oxygen species, which mediate oxygen-dependent killing of microorganisms, such as Mycobacterium tuberculosis. P22phox, encoded by CYBA, is the key regulatory subunit of NADPH oxidase. Our study aimed to investigate the association of CYBA polymorphisms with susceptibility to tuberculosis. Three SNPs (rs9932581, rs3794624 and rs4673) were genotyped in the discovery cohort composed of Chinese Han individuals. We found that the A allele of rs3794624 was a significant protective factor against tuberculosis (GA vs. GG: OR = 0.74, 95% CI 0.57-0.96; GA vs. GG+AA: OR = 0.73, 95% CI 0.56-0.95), which was then replicated in the Chinese Tibetan population (GA vs. GG: OR = 0.68, 95% CI 0.51-0.92; AA+GA vs. GG: OR = 0.70, 95% CI 0.52-0.93; GA vs. GG+AA: OR = 0.68, 95% CI 0.51-0.92). Meta-analysis including both cohorts identified overdominance as the best genetic model and provided robust evidence for the protective effect of the rs3794624 GA genotype against tuberculosis without any evidence of heterogeneity (GA vs. GG+AA: OR = 0.71, 95% CI 0.58-0.86). Our study found an association between the GA genotype of rs3794624 in CYBA with decreased tuberculosis susceptibility in two Chinese populations. Further analyses are needed to reveal the potential function of this SNP.

Peripheral artery disease: epidemiology and global perspectives

Global populations are undergoing a major epidemiological transition in which the burden of atherosclerotic cardiovascular diseases is shifting rapidly from high-income to low-income and middle-income countries (LMICs). Peripheral artery disease (PAD) is no exception, so that greater focus is now required on the prevention and management of this disease in less-advantaged countries. In this Review, we examine the epidemiology of PAD and, where feasible, take a global perspective. However, the dearth of publications in LMICs means an unavoidable over-reliance on studies in high-income countries. Research to date suggests that PAD might affect a greater proportion of women than men in LMICs. Although factors such as poverty, industrialization, and infection might conceivably influence the development of PAD in such settings, the ageing of the population and increase in traditional cardiovascular risk factors, such as smoking, diabetes mellitus, and hypertension, are likely to be the main driving forces.

Peripheral Artery Disease and Aortic Disease

We reviewed published MESA (Multi-Ethnic Study of Atherosclerosis) study articles concerning peripheral arterial disease, subclavian stenosis (SS), abdominal aortic calcium (AAC), and thoracic artery calcium (TAC). Important findings include, compared to non-Hispanic whites, lower ankle-brachial index (ABI) and more SS in African Americans, and higher ABI and less SS in Hispanic and Chinese Americans. Abnormal ABI and brachial pressure differences were associated with other subclinical cardiovascular disease (CVD) measures. Both very high and low ABI independently predicted increased CVD events. Looking at aortic measures, TAC and AAC were significantly associated with other subclinical CVD measures. Comparisons of AAC with coronary artery calcium (CAC) showed that both were less common in ethnic minority groups. However, although CAC was much more common in men than in women in multivariable analysis, this was not true of AAC. Also, when AAC and CAC were adjusted for each other in multivariable analysis, there was a stronger association for AAC than for CAC with CVD and total mortality.

9p21 locus rs10757278 is associated with advanced carotid atherosclerosis in a gender-specific manner

Single nucleotide polymorphisms from the chromosome locus 9p21 are reported to carry a risk for various cardiovascular diseases. One of the lead single nucleotide polymorphisms, rs10757278, was mostly investigated in association with coronary artery disease but rarely with carotid atherosclerosis. In this study, we aimed to analyze the association of rs10757278 A/G polymorphism with carotid plaque presence in advanced carotid atherosclerosis. The study included 803 participants, 486 patients with high-grade stenosis (>70%) who were undergoing carotid endarterectomy and 317 controls from Serbian population. Genotypes were determined using the real-time polymerase chain reaction. According to the recessive model of inheritance, GG genotype was significantly and independently associated with carotid plaque in females only (odds ratio 2.42, CI = 1.20-4.90, P = 0.013). Odds ratio was adjusted for age, body mass index, hypertension, TC, LDLC, HDLC and TG, and P value was corrected for multiple comparisons. Our preliminary findings suggest a gender-specific association of rs10757278 polymorphism with carotid plaque. Further studies on larger sample and in genetically and environmentally similar populations are needed.

CDKN2B Regulates TGFβ Signaling and Smooth Muscle Cell Investment of Hypoxic Neovessels

RATIONALE

Genetic variation at the chromosome 9p21 cardiovascular risk locus has been associated with peripheral artery disease, but its mechanism remains unknown.

OBJECTIVE

To determine whether this association is secondary to an increase in atherosclerosis, or it is the result of a separate angiogenesis-related mechanism.

METHODS AND RESULTS

Quantitative evaluation of human vascular samples revealed that carriers of the 9p21 risk allele possess a significantly higher burden of immature intraplaque microvessels than carriers of the ancestral allele, irrespective of lesion size or patient comorbidity. To determine whether aberrant angiogenesis also occurs under nonatherosclerotic conditions, we performed femoral artery ligation surgery in mice lacking the 9p21 candidate gene, Cdkn2b. These animals developed advanced hindlimb ischemia and digital autoamputation, secondary to a defect in the capacity of the Cdkn2b-deficient smooth muscle cell to support the developing neovessel. Microarray studies identified impaired transforming growth factor β (TGFβ) signaling in cultured cyclin-dependent kinase inhibitor 2B (CDKN2B)-deficient cells, as well as TGFβ1 upregulation in the vasculature of 9p21 risk allele carriers. Molecular signaling studies indicated that loss of CDKN2B impairs the expression of the inhibitory factor, SMAD-7, which promotes downstream TGFβ activation. Ultimately, this manifests in the upregulation of a poorly studied effector molecule, TGFβ1-induced-1, which is a TGFβ-rheostat known to have antagonistic effects on the endothelial cell and smooth muscle cell. Dual knockdown studies confirmed the reversibility of the proposed mechanism, in vitro.

CONCLUSIONS

These results suggest that loss of CDKN2B may not only promote cardiovascular disease through the development of atherosclerosis but may also impair TGFβ signaling and hypoxic neovessel maturation.