Neighborhood-level Social Vulnerability and Prevalence of Cardiovascular Risk Factors and Coronary Heart Disease.

Social determinants of health are implicated in the geographic variation in cardiovascular diseases (CVDs). The social vulnerability index (SVI) is an estimate of a neighborhood's potential for deleterious outcomes when faced with natural disasters or disease outbreaks. We sought to investigate the association of the SVI with cardiovascular risk factors and the prevalence of coronary heart disease (CHD) in the United States at the census tract level. We linked census tract SVI with prevalence of census tract CVD risk factors (smoking, high cholesterol, diabetes, high blood pressure, low physical activity and obesity), and prevalence of CHD obtained from the behavioral risk factor surveillance system. We evaluated the association between SVI, its sub-scales, CVD risk factors and CHD prevalence using linear regression. Among 72,173 census tracts, prevalence of all cardiovascular risk factors increased linearly with SVI. A higher SVI was associated with a higher CHD prevalence (R2 = 0.17, P < 0.0001). The relationship between SVI and CHD was stronger when accounting for census-tract median age (R2 = 0.57, P < 0.0001). A multivariable linear regression model including 4 SVI themes separately explained considerably more variation in CHD prevalence than the composite SVI alone (50.0% vs 17.3%). Socioeconomic status and household composition and disability were the SVI themes most closely associated with cardiovascular risk factors and CHD prevalence. In the United States, social vulnerability can explain significant portion of geographic variation in CHD, and its risk factors. Neighborhoods with high social vulnerability are at disproportionately increased risk of CHD and its risk factors. Social determinants of health are implicated in the geographic variation in cardiovascular diseases (CVDs). We investigated the association of social vulnerability index (SVI) with cardiovascular risk factors and the prevalence of coronary heart disease (CHD) in the United States at the census tract level. We show that cardiovascular risk factors and CHD were more common with higher SVI. A multivariable linear regression model including 4 SVI themes separately explained considerably more variation in CHD prevalence than the composite SVI alone (50.0% vs 17.3%). Socioeconomic status and household composition and/or disability were the SVI themes most closely associated with cardiovascular risk factors and CHD prevalence.

Anisocytosis is associated with myocardial fibrosis and exercise capacity in heart failure with preserved ejection fraction.

BACKGROUND: Red Blood Cell Distribution Width (RDW), a measure of variability in size of circulating red blood cells and is a marker of inflammation. OBJECTIVES: We sought to test the hypothesis that RDW reflects an inflammatory milieu permissive for cardiac fibrosis in those with Heart Failure and preserved ejection fraction (HFpEF). METHODS: We analyzed the association between RDW and fibrosis in two separate cohorts. Cohort 1 (n = 200) was a retrospective analysis of blood biomarkers measured in the RELAX trial (Clinicaltrials.gov NCT00763867) and Cohort 2 (n = 160) included a single center cohort of patients with preserved ventricular function referred for cardiac magnetic resonance imaging (cMRI). Linear regression was used to adjust for potential confounders, and a mediation analysis used to explore relationships with exercise intolerance (peak VO2 max). RESULTS: Within Cohort 1, anisocytosis (RDW > 14.5) was prevalent (49.5%) and was associated with greater baseline clinical comorbidities, a lower Peak VO2 and more frequent heart failure hospitalizations. The RDW was associated with biomarkers of inflammation and cardiac fibrosis. In Cohort 2, RDW was associated with cMRI myocardial fibrosis (extracellular volume; Spearman's rho=0.38, P<0.001) which was independent of age, sex, LV ejection fraction, and hematocrit (P = 0.026). Individuals with both anisocytosis and myocardial fibrosis identified a subgroup of at high risk for 2-year mortality (HR 16.28 [4.30-61.66], P<0.001). CONCLUSIONS: In two independent cohorts of patients with HFpEF, elevated RDW is associated reduced exercise capacity and greater fibrosis as measured by serum biomarkers and cMRI. Additional studies are needed to validate this novel relationship.

Socioeconomic Deprivation and Premature Cardiovascular Mortality in the United States.

OBJECTIVE: To determine the variability in county cardiovascular (CV) premature mortality explained by integrated metrics of socioeconomic deprivation and to explore temporal trends in CV mortality by county socioeconomic deprivation. METHODS: This is a cross-sectional analysis of US county-level death certificate data from 1999 to 2018 of age-adjusted premature (25 to 64 years) CV mortality. Integrated metrics of socioeconomic deprivation (Social Deprivation Index [SDI] and county Area Deprivation Index [ADI]) were associated with mortality using linear regression analysis. Relative change in county CV mortality from 1999 to 2018 was associated with indices using linear regression analysis. RESULTS: Counties with higher quartile SDI and ADI had significantly higher total, non-Hispanic Black/African American, and female premature CV mortality (P<.001). Both SDI and ADI were significantly associated with CV mortality by linear regression (P<.001) explaining 40% and 44% of county variability in CV mortality, respectively. Counties with lower deprivation indices experienced a larger decreased in premature CV mortality (P<.001). CONCLUSION: This study demonstrates an association between multiple integrated metrics of socioeconomic deprivation and premature cardiovascular mortality and shows potentially worsening disparities.

Ambient Air Pollution and Atherosclerosis: Recent Updates.

PURPOSE OF REVIEW: During the past century, exposure to particulate matter (PM) air pollution < 2.5 µm in diameter (PM2.5) has emerged as an all-pervading element of modern-day society. This increased exposure has come at the cost of heightened risk for cardiovascular (CV) morbidity and mortality. Not only can short-term PM2.5 exposure trigger acute CV events in susceptible individuals, but longer-term exposure over years augments CV risk to a greater extent in comparison with short-term exposure. The purpose of this review is to examine the available evidence for how ambient air pollution exposure may precipitate events at various time frames. RECENT FINDINGS: Recent epidemiological studies have demonstrated an association between ambient PM2.5 exposure and the presence and progression of atherosclerosis in humans. Multiple animal exposure experiments over two decades have provided strong corroborative evidence that chronic exposure in fact does enhance the progression and perhaps vulnerability characteristics of atherosclerotic lesions. Evidence from epidemiological studies including surrogates of atherosclerosis, human translational studies, and mechanistic investigations utilizing animal studies have improved our understanding of how ambient air pollution may potentiate atherosclerosis and precipitate cardiovascular events. Even so, future research is needed to fully understand the contribution of different constituents in ambient air pollution-mediated atherosclerosis as well as how other systems may modulate the impact of exposure including adaptive immunity and the gut microbiome. Nevertheless, due to the billions of people continually exposed to PM2.5, the long-term pro-atherosclerotic effects of this ubiquitous air pollutant are likely to be of enormous and growing global public health importance.

Endothelin-1 and peak oxygen consumption in patients with heart failure with preserved ejection fraction.

BACKGROUND: Mechanisms of exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF) are not well understood. Pulmonary hypertension, a common accompaniment in patients with HFpEF, is associated with poor outcomes. While Endothelin -1 (ET-1) plays a mechanistic role in pulmonary hypertension, its role in exercise intolerance in HFpEF is not well established. OBJECTIVE: To explore the association between plasma ET-1 levels and maximal oxygen consumption (pVO2), and their changes over 24 weeks in HFpEF. METHODS: This is a post-hoc analysis of the Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure with Preserved Ejection Fraction (RELAX) trial. We performed linear regressions to assess the relationship between plasma ET-1 and pVO2. We also used linear regressions to determine whether ET-1 was associated with change in peak VO2 (ΔpVO2). RESULTS: A total of 210 patients were included. Baseline plasma ET-1 levels were associated with older age, higher NT-proBNP levels, higher serum creatinine levels, and higher prevalence of atrial fibrillation. Patients with higher ET1 levels also had higher plasma galectin-3 and CITP levels. After multiple adjustments, baseline ET1 levels were associated with lower pVO2 (ß -0.927, SE 0.196, p < 0.001). Over 24 weeks, the change in ET1 levels was associated with the change in pVO2 (multivariable adjusted ß -0.415, SE 0.115, p = 0.018). Baseline ET1 levels did not modify the effect of sildenafil on change in peak VO2. CONCLUSIONS: Plasma ET1 levels are significantly associated with lower exercise oxygen consumption both at baseline and longitudinally over 24 weeks. Future studies should explore Endothelin-1 antagonism to improve exercise tolerance in HFpEF.

Association between ambient air pollution and county-level cardiovascular mortality in the United States by social deprivation index.

BACKGROUND: Air pollution and socioeconomic status have both been strongly associated with cardiovascular (CV) outcomes. We sought to determine if socioeconomic status modifies the risk association between fine particulate matter air pollution (PM2.5) and CV mortality. METHODS: We linked county-level age-adjusted CV mortality data from Multiple Cause of Death files (2000-2016, ICD10: I00-I99) with 2015 Social Deprivation Index (SDI), a validated estimate of socioeconomic status, and modelled spatial and temporal mean annual PM2.5 exposures (2012-2018). Higher SDI suggests greater deprivation and lower socioeconomic status. Associations between PM2.5 and age adjusted CV mortality were estimated using linear models. RESULTS: A total of 5,769,315 cardiovascular deaths from 2012-2018 across 3106 United States counties were analyzed. Both PM2.5 (ß (SE) 7.584 (0.938), P < .001) and SDI scores (ß (SE) 0.591 (0.140), P < .001) were independently associated with age-adjusted CV mortality (R2 = 0.341). The association between PM2.5 and CV mortality were stronger among counties with highest SDI, P value for interaction = .012. CONCLUSION: Social deprivation and PM2.5 exposures were independently associated with county level age-adjusted CV mortality. The associations between PM2.5 and CV mortality were stronger in counties with high vs low social deprivation. SDI and PM2.5 represent potential targets to reduce CV mortality disparities and interventions to reduce PM2.5 exposure may be most impactful in communities of low socioeconomic status.

Ambient Air Pollution and Atherosclerosis: Insights Into Dose, Time, and Mechanisms.

Ambient air pollution due to particulate matter ≤2.5 µ is the leading environmental risk factor contributing to global mortality, with a preponderant majority of these deaths attributable to atherosclerotic cardiovascular disease (ASCVD) causes such as stroke and myocardial infarction. Epidemiological studies in humans have provided refined estimates of exposure risk, with evidence suggesting that risk association with particulate matter ≤2.5 levels and ASCVD continues at levels well below air quality guidelines in North America and Europe. Mechanistic studies in animals and humans have provided a framework of understanding of the duration and pathways by which air pollution exposure may predispose to atherosclerosis. Although acute exposure to particulate matter ≤2.5 is associated with oxidative stress and inflammation, system transmission of signals from the lungs to extrapulmonary sites may involve direct translocation of components, biologic intermediates, and autonomic nervous system activation. End-organ effector pathways such as endothelial barrier disruption/dysfunction, thrombosis, vasoconstriction/increased blood pressure, and plaque instability, may contribute to ASCVD. The strength of the association of air pollution with ASCVD offers an opportunity to mitigate its consequences. Although elimination of anthropogenic sources of air pollution with a switch to clean energy provides the ultimate solution, this may not be possible in the interim and may require personal protection efforts and an integrated approach to managing risk posed by air pollution for ASCVD.

Soluble Tumor Necrosis Factor Receptor 1 is Associated With Cardiovascular Risk in Persons With Coronary Artery Calcium Score of Zero.

BACKGROUND: A coronary artery calcium (CAC) score of zero confers a low but nonzero risk of atherosclerotic cardiovascular events (CVD) in asymptomatic patient populations, and additional risk stratification is needed to guide preventive interventions. Soluble tumor necrosis factor receptors (sTNFR-1 and sTNFR-2) are shed in the context of TNF-alpha signaling and systemic inflammation, which play a role in atherosclerosis and plaque instability. We hypothesized that serum sTNFR-1 concentrations may aid in cardiovascular risk stratification among asymptomatic patients with a CAC score of zero. METHODS: We included all participants with CAC=0 and baseline sTNFR-1 measurements from the prospective cohort Multi-Ethnic Study of Atherosclerosis (MESA). The primary outcome was a composite CVD event (myocardial infarction, stroke, coronary revascularization, cardiovascular death). RESULTS: The study included 1471 participants (mean age 57.6 years, 64% female), with measured baseline sTNFR-1 ranging from 603 pg/mL to 5544 pg/mL (mean 1294 pg/mL ±378.8 pg/mL). Over a median follow-up of 8.5 years, 37 participants (2.5%) experienced a CVD event. In multivariable analyses adjusted for Framingham Score, doubling of sTNFR-1 was associated with a 3-fold increase in the hazards of CVD (HR 3.0, 95% CI: 1.48-6.09, P = 0.002), which remained significant after adjusting for traditional CVD risk factors individually (HR 2.29; 95% CI: 1.04-5.06, P=0.04). Doubling of sTNFR-1 was also associated with progression of CAC >100, adjusted for age (OR 2.84, 95% CI: 1.33-6.03, P=0.007). CONCLUSIONS: sTNFR-1 concentrations are associated with more CVD events in participants with a CAC score of zero. Utilizing sTNFR-1 measurements may improve cardiovascular risk stratification and guide primary prevention in otherwise low-risk individuals.

Exposure to Air Pollution Disrupts Circadian Rhythm through Alterations in Chromatin Dynamics.

Particulate matter ≤2.5µm (PM2.5) air pollution is a leading environmental risk factor contributing disproportionately to the global burden of non-communicable disease. We compared impact of chronic exposure to PM2.5 alone, or with light at night exposure (LL) on metabolism. PM2.5 induced peripheral insulin resistance, circadian rhythm (CR) dysfunction, and metabolic and brown adipose tissue (BAT) dysfunction, akin to LL (with no additive interaction between PM2.5 and LL). Transcriptomic analysis of liver and BAT revealed widespread but unique alterations in CR genes, with evidence for differentially accessible promoters and enhancers of CR genes in response to PM2.5 by ATAC-seq. The histone deacetylases 2, 3, and 4 were downregulated with PM2.5 exposure, with increased promoter occupancy by the histone acetyltransferase p300 as evidenced by ChIP-seq. These findings suggest a previously unrecognized role of PM2.5 in promoting CR disruption and metabolic dysfunction through epigenetic regulation of circadian targets.

Oxidative stress pathways of air pollution mediated toxicity: Recent insights.

Ambient air pollution is a leading environmental cause of morbidity and mortality globally with most of the outcomes of cardiovascular origin. While numerous mechanisms are proposed to explain the link between air pollutants and cardiovascular events, the evidence supports a role for oxidative stress as a critical intermediary pathway in the transduction of systemic responses in the cardiovascular system. Indeed, alterations in vascular function are a critical step in the development of cardiometabolic disorders such as hypertension, diabetes, and atherosclerosis. This review will provide an overview of the impact of particulate and gaseous pollutants on oxidative stress from human and animal studies published in the last five years. We discuss current gaps in knowledge and evidence to date implicating the role of oxidative stress with an emphasis on inhalational exposures. We conclude with the identification of gaps, and an exhortation for further studies to elucidate the impact of oxidative stress in air pollution mediated effects.

Evidence-Based Medical Management of Peripheral Artery Disease.

Peripheral artery disease is an atherosclerotic disease of the lower extremities associated with high cardiovascular mortality. Management of this condition may include lifestyle modifications, medical management, endovascular repair, or surgery. The medical approach to peripheral artery disease is multifaceted and includes cholesterol reduction, antiplatelet therapy, anticoagulation, peripheral vasodilators, blood pressure management, exercise therapy, and smoking cessation. Adherence to this regimen can reduce limb-related complications like critical limb ischemia and amputation, as well as systemic complications of atherosclerosis like stroke and myocardial infarction. Relative to coronary artery disease, peripheral artery disease is an undertreated condition. In this article, we explore the evidence behind medical therapies for the management of peripheral artery disease.