Ectopic fat is linked to prior cardiovascular events in men with HIV

Exercise to Prevent Accelerated Vascular Aging in People Living With HIV

Given advances in antiretroviral therapy, the mortality rate for HIV infection has dropped considerably over recent decades. However, people living with HIV (PLWH) experience longer life spans coupled with persistent immune activation despite viral suppression and potential toxicity from long-term antiretroviral therapy use. Consequently, PLWH face a cardiovascular disease (CVD) risk more than twice that of the general population, making it the leading cause of death among this group. Here, we briefly review the epidemiology of CVD in PLWH highlighting disparities at the intersections of sex and gender, age, race/ethnicity, and the contributions of social determinants of health and psychosocial stress to increased CVD risk among individuals with marginalized identities. We then overview the pathophysiology of HIV and discuss the primary factors implicated as contributors to CVD risk among PLWH on antiretroviral therapy. Subsequently, we highlight the functional evidence of premature vascular dysfunction as an early pathophysiological determinant of CVD risk among PLWH, discuss several mechanisms underlying premature vascular dysfunction in PLWH, and synthesize current research on the pathophysiological mechanisms underlying accelerated vascular aging in PLWH, focusing on immune activation, chronic inflammation, and oxidative stress. We consider understudied aspects such as HIV-related changes to the gut microbiome and psychosocial stress, which may serve as mechanisms through which exercise can abrogate accelerated vascular aging. Emphasizing the significance of exercise, we review various modalities and their impacts on vascular health, proposing a holistic approach to managing CVD risks in PLWH. The discussion extends to critical future study areas related to vascular aging, CVD, and the efficacy of exercise interventions, with a call for more inclusive research that considers the diversity of the PLWH population.

The Role of Epicardial Adipose Tissue in Acute Coronary Syndromes, Post-Infarct Remodeling and Cardiac Regeneration

Epicardial adipose tissue (EAT) is a fat deposit surrounding the heart and located under the visceral layer of the pericardium. Due to its unique features, the contribution of EAT to the pathogenesis of cardiovascular and metabolic disorders is extensively studied. Especially, EAT can be associated with the onset and development of coronary artery disease, myocardial infarction and post-infarct heart failure which all are significant problems for public health. In this article, we focus on the mechanisms of how EAT impacts acute coronary syndromes. Particular emphasis was placed on the role of inflammation and adipokines secreted by EAT. Moreover, we present how EAT affects the remodeling of the heart following myocardial infarction. We further review the role of EAT as a source of stem cells for cardiac regeneration. In addition, we describe the imaging assessment of EAT, its prognostic value, and its correlation with the clinical characteristics of patients.

Sarcopenic Obesity Phenotypes in Patients With HIV: Implications for Cardiovascular Prevention and Rehabilitation

BACKGROUND

We aimed to describe prevalence, incidence, and risk factors for sarcopenic obesity (SO) phenotypes in people living with HIV (PWH) and their association with subclinical cardiovascular disease (CVD).

METHODS

Observational, longitudinal study of PWH. A minimum of 1 criterion was necessary to diagnose sarcopenia: weak hand grip (HG), low appendicular skeletal muscle index (ASMI), short physical performance battery (SPPB < 11). Obesity was defined as body mass index (BMI) ≥ 30 kg/m2 or visceral adipose tissue (VAT) ≥ 160 cm2. These variables combined generated 5 SO phenotypes: severe SO: low HG + low ASMI + low SPPB + high BMI; SO1: weak HG + high VAT; SO2: weak HG + high BMI; SO3: low ASMI + high VAT; SO4: low ASMI + high BMI. Subclinical CVD was defined as carotid intima-media thickness (IMT) ≥ 1 mm, presence of carotid plaque, or coronary artery calcification (CAC) score > 10.

RESULTS

Among 2379 male PWH 72%, median age was 52 years, median HIV vintage 21 years, and median BMI 24 kg/m2. Two PWH had severe SO. The prevalence of SO1-SO4 was 19.7%, 3.6%, 20.8% and 0.8%, respectively. Incidence of SO1-SO4 was 6.90, 1.2, 5.6, and 0.29 × 100 person-years, respectively. SO1 was associated with risk of IMT ≥ 1, and SO3 with risk of CAC score > 10.

CONCLUSIONS

There was a large variability in incidence and prevalence of SO phenotypes. The presence of SO may have important implications for cardiovascular prevention and cardiac rehabilitation of PWH who suffered events.

Prevalence and incidence of stroke among people with HIV

OBJECTIVE

We aimed to obtain more precise estimates of stroke to address the wide variation of stroke burden among people with HIV (PWH) in different clinical settings.

DESIGN

Systematic review and meta-analysis.

METHODS

We systematically searched PubMed, EMBASE, and Web of Science for original articles reporting the prevalence and incidence of stroke among PWH up to November 23, 2022. Der Simonian-Laird random effects were used to obtain pooled estimates and 95% confidence intervals (CIs).

RESULTS

We included 17 observational studies covering 1 749 003 PWH on estimation of prevalence, and 17 cohort studies covering 249 606 PWH on estimation of incidence. The pooled prevalence of stroke was 1.30% (95% CI: 1.01%, 1.59%) for PWH aged at least 15 years, and 3.98% (95% CI: 2.45%, 5.51%) for PWH aged at least 50 years. The pooled incidence of stroke was 17.86 per 10 000 person-years (95% CI: 15.96, 19.76), meanwhile, the pooled incidence of ischemic stroke (31.50 per 10 000 person-years; 95% CI: 11.11, 51.89) was higher than hemorrhagic stroke (4.43 per 10 000 person-years; 95% CI: 1.95, 6.91) among PWH aged at least 15 years.

CONCLUSION

The prevalence of stroke was nearly one per hundred among PWH aged ≥15 years, and reached four per hundred for those aged ≥50 years. The occurrence of stroke is common during HIV progression, particularly ischemic stroke. Therefore, more efforts should be made on implementing policies, strategies, and programs aimed at identifying the risk factors, improving treatment, and facilitating rehabilitation for stroke to reduce the disease burden among PWH.

The association of epicardial adipose tissue volume and density with coronary calcium in HIV-positive and HIV-negative patients

AIMS

We sought to assess and compare the association of epicardial adipose tissue (EAT) with cardiovascular disease (CVD) in HIV-positive and HIV-negative groups.

METHODS AND RESULTS

Using existing clinical databases, we analyzed 700 patients (195 HIV-positive, 505 HIV-negative). CVD was quantified by the presence of coronary calcification from both dedicated cardiac computed tomography (CT) and non-dedicated CT of the thorax. Epicardial adipose tissue (EAT) was quantified using dedicated software. The HIV-positive group had lower mean age (49.2 versus 57.8, p < 0.005), higher proportion of male sex (75.9 % versus 48.1 %, p < 0.005), and lower rates of coronary calcification (29.2 % versus 58.2 %, p < 0.005). Mean EAT volume was also lower in the HIV-positive group (68mm3 versus 118.3mm3, p < 0.005). Multiple linear regression demonstrated EAT volume was associated with hepatosteatosis (HS) in the HIV-positive group but not the HIV-negative group after adjustment for BMI (p < 0.005 versus p = 0.066). In the multivariate analysis, after adjustment for CVD risk factors, age, sex, statin use, and body mass index (BMI), EAT volume and hepatosteatosis were significantly associated with coronary calcification (odds ratio [OR] 1.14, p < 0.005 and OR 3.17, p < 0.005 respectively). In the HIV-negative group, the only significant association with EAT volume after adjustment was total cholesterol (OR 0.75, p = 0.012).

CONCLUSIONS

We demonstrated a strong and significant independent association of EAT volume and coronary calcium, after adjustment, in HIV-positive group but not in the HIV-negative group. This result hints at differences in the mechanistic drivers of atherosclerosis between HIV-positive and HIV-negative groups.

Diabetes in HIV: the Link to Weight Gain

PURPOSE OF REVIEW

The burden of metabolic diseases, including type 2 diabetes mellitus (T2DM), is rising among persons with HIV (PWH) on antiretroviral therapy (ART). This increase coincides with an aging population and a greater proportion who are overweight/obese. This review summarizes the changing epidemic of T2DM on contemporary ART, the role of weight gain, and therapeutic options.

RECENT FINDINGS

Recent studies confirm that PWH face an epidemic of obesity and T2DM, similar to the general population. Contemporary ART is associated with greater weight gain and may contribute to the risk of T2DM. Recent advances in medical weight loss therapy offer a way forward in the prevention and treatment of weight-associated T2DM. Weight gain is one of the biggest contributors to T2DM in PWH. Future studies on the role of adipose tissue distribution, adipose tissue function and clinical use of effective weight loss medications may change the paradigm of care for PWH.

Ectopic Fat and Cardiac Health in People with HIV: Serious as a Heart Attack

PURPOSE OF REVIEW

This study aims to summarize knowledge of alterations in adipose tissue distribution among people with HIV (PWH), with a focus on the cardiac depot and how this relates to the known higher risk of cardiovascular disease in this unique population.

RECENT FINDINGS

Similar to the general population, cardiac fat depots mirror visceral adipose tissue in PWH. However, altered fat distribution, altered fat quality, and higher prevalence of enlarged epicardial adipose tissue depots are associated with increased coronary artery disease among PWH. Adipose tissue disturbances present in PWH ultimately contribute to increased risk of cardiovascular disease beyond traditional risk factors. Future research should aim to understand how regulating adipose tissue quantity and quality can modify cardiovascular risk.

Associations of Hepatosteatosis With Cardiovascular Disease in HIV-Positive and HIV-Negative Patients: The Liverpool HIV-Heart Project

BACKGROUND

Hepatosteatosis (HS) has been associated with cardiovascular disorders in the general population. We sought to investigate whether HS is a marker of cardiovascular disease (CVD) risk in HIV-positive individuals, given that metabolic syndrome is implicated in the increasing CVD burden in this population.

AIMS

To investigate the association of HS with CVD in HIV-positive and HIV-negative individuals.

METHODS AND RESULTS

We analyzed computed tomography (CT) images of 1306 subjects of whom 209 (16%) were HIV-positive and 1097 (84%) HIV-negative. CVD was quantified by the presence of coronary calcification from both dedicated cardiac CT and nondedicated thorax CT. HS was diagnosed from CT data sets in those with noncontrast dedicated cardiac CT and those with venous phase liver CT using previously validated techniques. Previous liver ultrasound was also assessed for the presence of HS. The HIV-positive group had lower mean age (P < 0.005), higher proportions of male sex (P < 0.005), and more current smokers (P < 0.005). The HIV-negative group had higher proportions of hypertension (P < 0.005), type II diabetes (P = 0.032), dyslipidemia (P < 0.005), statin use (P = 0.008), and HS (P = 0.018). The prevalence of coronary calcification was not significantly different between the groups. Logistic regression (LR) demonstrated that in the HIV-positive group, increasing age [odds ratio (OR): 1.15, P < 0.005], male sex (OR 3.37, P = 0.022), and HS (OR 3.13, P = 0.005) were independently associated with CVD. In the HIV-negative group, increasing age (OR: 1.11, P < 0.005), male sex (OR 2.97, P < 0.005), current smoking (OR 1.96, P < 0.005), and dyslipidemia (OR 1.66, P = 0.03) were independently associated with CVD. Using a machine learning random forest algorithm to assess the variables of importance, the top 3 variables of importance in the HIV-positive group were age, HS, and male sex. In the HIV-negative group, the top 3 variables were age, hypertension and male sex. The LR models predicted CVD well, with the mean area under the receiver operator curve (AUC) for the HIV-positive and HIV-negative cohorts being 0.831 [95% confidence interval (CI): 0.713 to 0.928] and 0.786 (95% CI: 0.735 to 0.836), respectively. The random forest models outperformed LR models, with a mean AUC in HIV-positive and HIV-negative populations of 0.877 (95% CI: 0.775 to 0.959) and 0.828 (95% CI: 0.780 to 0.873) respectively, with differences between both methods being statistically significant.

CONCLUSION

In contrast to the general population, HS is a strong and independent predictor of CVD in HIV-positive individuals. This suggests that metabolic dysfunction may be attributable to the excess CVD risk seen with these patient groups. Assessment of HS may help accurate quantification of CVD risk in HIV-positive patients.

Probing the Interface of HIV and Inflammaging

PURPOSE OF REVIEW

Systemic inflammation increases as a consequence of aging (inflammaging) and contributes to age-related morbidities. Inflammation in people living with HIV is elevated compared with the general population even after prolonged suppression of viremia with anti-retroviral therapy. Mechanisms that contribute to inflammation during aging and in treated HIV disease are potentially interactive, leading to an exaggerated inflammatory phenotype in people with HIV.

RECENT FINDINGS

Recent studies highlight roles for anti-retroviral therapy, co-infections, immune system alterations, and microbiome perturbations as important contributors to HIV-associated inflammation. These factors likely contribute to increased risk of age-related morbidities in people living with HIV. Understanding mechanisms that exaggerate the inflammaging process in people with HIV may lead to improved intervention strategies, ultimately, extending both lifespan and healthspan.

Changes in central adipose tissue after switching to integrase inhibitors

Background: Treatment with integrase strand transfer inhibitors (INSTIs) has been associated with excess weight gain, however the long-term effect of INSTI-based regimens on adipose tissue (AT) compartments remains unknown.Objectives: To evaluate the effect of switching to an INSTI on visceral (VAT) and subcutaneous (SAT) AT in virologically-suppressed adults with HIV.Methods: We performed a retrospective observational cohort study of ART experienced adults referred to the metabolic Clinic of the University of Modena and Reggio Emilia who had ≥2 assessments of body composition by abdominal computed tomography. An interrupted time series model with mixed-effect model incorporated was used to calculate VAT and SAT change rate, adjusting for smoking status, use of alcohol, and physical activity.Results: A total of 698 patients were included: 156 who switched to an INSTI-based regimen and 542 who did not. After switch to INSTI, mean SAT area increased approximately 3-fold (before 0.27 vs after 0.73 cm²/month; p = 0.011), and VAT area 7-fold (0.18 vs 1.30 cm²/month; p < 0.001).Conclusions: Among PLWH on ART, both SAT and VAT gain accelerated after switching to an INSTI-based regimen. The associations between INSTIs and central adiposity require further investigation.

A Meta-Analysis of Different Types of Cardiac Adipose Tissue in HIV Patients

Background

Antiretroviral therapy transformed HIV infection into a chronic disease but accelerated cardiovascular disease (CVD). Both of epicardial adipose tissue (EAT) and pericardial fat (PCF) have close relationships with CVD. The associations between these two cardiac adipose tissue and HIV are unclear.

Methods

Eligible studies were searched in PubMed, Embase, Web of Science, and Scopus from database inception to March 24, 2020. The summarized standard mean difference (SMD) or weighted mean difference (WMD) with 95% confidence intervals (CIs) was used to assess the association between EAT/PCF and HIV. Subgroup analysis was performed based on EAT types. Trial sequential analysis was conducted to estimate whether the evidence of the results is sufficient.

Results

In total, 2561 HIV patients and 1767 non-HIV participants were included. Compared to the control group, EAT was significantly higher in the HIV overall group and subgroup with EAT thickness (SMD = 0.59, 95% CI: 0.24-0.95, P = 0.001; SMD = 1.10, 95% CI: 0.41-1.79, P = 0.002); however, the EAT volume and PCF volume were unchanged in the HIV group (SMD = 0.16, 95% CI: -0.07-0.39, P = 0.169; WMD = 10.78, 95% CI: -14.11-35.67, P = 0.396). Trial sequential analysis indicated that the available samples were sufficient in the HIV overall group and subgroup with EAT thickness, and more studies are needed for EAT volume and PCF volume.

Conclusions

EAT thickness was significantly higher in patients with HIV. The association between EAT/PCF volume and HIV needs more studies to confirm.

Obesity and Weight Gain in Persons with HIV

PURPOSE OF REVIEW

The proportion of overweight and obese persons with HIV (PWH) has increased since the introduction of antiretroviral therapy (ART). We aim to summarize recent literature on risks of weight gain, discuss adipose tissue changes in HIV and obesity, and synthesize current understanding of how excess adiposity and HIV contribute to metabolic complications.

RECENT FINDINGS

Recent studies have implicated contemporary ART regimens, including use of integrase strand transfer inhibitors and tenofovir alafenamide, as a contributor to weight gain, though the mechanisms are unclear. Metabolic dysregulation is linked to ectopic fat and alterations in adipose immune cell populations that accompany HIV and obesity. These factors contribute to an increasing burden of metabolic diseases in the aging HIV population. Obesity compounds an increasing burden of metabolic disease among PWH, and understanding the role of fat partitioning and HIV- and ART-related adipose tissue dysfunction may guide prevention and treatment strategies.

Epicardial Adipose Tissue: Clinical Biomarker of Cardio-Metabolic Risk

Epicardial adipose tissue (EAT) is part of the visceral adipose tissue (VAT) that surrounds the heart and it is a quantifiable, modifiable, and multifaceted tissue that has both local and systemic effects. When EAT is enlarged, EAT contributes to atherosclerotic cardiovascular disease (ASCVD) risk and plays a role in the development of metabolic syndrome (MetS). In this review, we will discuss the role of EAT in various facets of MetS, including type 2 diabetes mellitus (T2DM) and insulin resistance. We examine the association between EAT and liver steatosis. We also address the correlations of EAT with HIV therapy and with psoriasis. We discuss racial differences in baseline EAT thickness. We conclude that EAT measurement serves as a powerful potential diagnostic tool in assessing cardiovascular and metabolic risk. Measurement of EAT is made less costly, more convenient, and yet accurate and reliable by transthoracic echocardiography. Furthermore, modification of EAT thickness has therapeutic implications for ASCVD, T2DM, and MetS.

Systemic Inflammation Characterizes Lack of Metabolic Health in Nonobese HIV-Infected Men

Background

Increasing body mass index (BMI) is generally associated with loss of metabolic health, although some obese individuals remain metabolically healthy. Among nonobese men, HIV infection has been associated with a lower prevalence of metabolic health.

Methods

We conducted a cross-sectional analysis of 470 HIV-infected and 368 HIV-uninfected men enrolled in the Multicenter AIDS Cohort Study Cardiovascular substudy. Circulating biomarker levels were compared by BMI category and by HIV serostatus. Poisson regression with robust variance determined associations between metabolic health and circulating inflammatory biomarker levels after adjusting for factors previously associated with metabolic health.

Results

HIV-infected men were younger and less likely to be obese. Among HIV-infected, normal weight metabolically healthy men (compared to unhealthy) had significantly lower circulating levels of interleukin- (IL-) 6, soluble tumor necrosis factor receptors (sTNFR) I and II, and homeostatic model assessment of insulin resistance (HOMA-IR), higher adiponectin, less visceral fat, and more subcutaneous fat. Among HIV-uninfected normal weight men and obese men (regardless of HIV serostatus), metabolic health was associated only with higher levels of adiponectin, less visceral fat, and lower HOMA-IR values. In multivariate analyses restricted to HIV-infected men, lower hs-CRP, sTNFRI, sTNFRII, and HOMA-IR and higher adiponectin levels were associated with metabolic health. Additional adjustment for visceral adiposity did not alter results.

Conclusions

Among HIV-infected normal weight men, metabolic health was associated with less systemic inflammation, a relationship that, among normal weight men, was unique to HIV+ men and did not exist among obese men of either HIV serostatus.

Heart fat in HIV: marker or mediator of risk?

PURPOSE OF REVIEW

The review aims to summarize the literature describing the clinical impact of cardiac fat depots in patients with HIV infection.

RECENT FINDINGS

People living with HIV (PLHIV) have accelerated rates of cardiovascular disease, and are prone to the development of ectopic fat deposition. Specifically, PLHIV have higher volumes of epicardial and intracardiac fat quantified by noninvasive imaging. Higher volumes of epicardial fat may be related to antiretroviral therapy duration and chronic inflammation, independently of other measures of body adiposity such as BMI. They have been associated with increased coronary artery calcium, myocardial perfusion defects, death, and myocardial infarction. The association with risk may be partly mediated through direct actions of cytokines and adipokines produced by the adipose tissue. Furthermore, HIV-infected patients have increased myocardial fat deposition that is also associated with antiretroviral therapy duration, and may be responsible for myocardial systolic and diastolic dysfunction.

SUMMARY

PLHIV have increased fat deposition surrounding and inside the heart that may serve as an important imaging marker of risk but may also directly mediate coronary artery disease and cardiac dysfunction. Although robust data of targeted therapies is lacking, some pharmacotherapies may be able to reduce cardiac fat volumes. In the meantime, as the evidence grows, physicians may consider intensifying preventive strategies and monitoring in patients with abnormal heart fat on noninvasive imaging.

The Fat of the Matter: Obesity and Visceral Adiposity in Treated HIV Infection

PURPOSE OF REVIEW

The aim of this review is to summarize knowledge of the prevalence, relevant physiology, and consequences of obesity and visceral adiposity in HIV-infected adults, including highlighting gaps in current knowledge and future research directions.

RECENT FINDINGS

Similar to the general population, obesity prevalence is increasing among HIV-infected persons, and obesity and visceral adiposity are associated with numerous metabolic and inflammatory sequelae. However, HIV- and antiretroviral therapy (ART)-specific factors may contribute to fat gain and fat quality in treated HIV infection, particularly to the development of visceral adiposity, and sex differences may exist. Obesity and visceral adiposity commonly occur in HIV-infected persons and have significant implications for morbidity and mortality. Future research should aim to better elucidate the HIV- and ART-specific contributors to obesity and visceral adiposity in treated HIV infection, with the goal of developing targeted therapies for the prevention and treatment of obesity and visceral adiposity in the modern ART era.

Adipose Tissue in HIV Infection

HIV infection and antiretroviral therapy (ART) treatment exert diverse effects on adipocytes and stromal-vascular fraction cells, leading to changes in adipose tissue quantity, distribution, and energy storage. A HIV-associated lipodystrophic condition was recognized early in the epidemic, characterized by clinically apparent changes in subcutaneous, visceral, and dorsocervical adipose depots. Underlying these changes is altered adipose tissue morphology and expression of genes central to adipocyte maturation, regulation, metabolism, and cytokine signaling. HIV viral proteins persist in circulation and locally within adipose tissue despite suppression of plasma viremia on ART, and exposure to these proteins impairs preadipocyte maturation and reduces adipocyte expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) and other genes involved in cell regulation. Several early nucleoside reverse transcriptase inhibitor and protease inhibitor antiretroviral drugs demonstrated substantial adipocyte toxicity, including reduced mitochondrial DNA content and respiratory chain enzymes, reduced PPAR-γ and other regulatory gene expression, and increased proinflammatory cytokine production. Newer-generation agents, such as integrase inhibitors, appear to have fewer adverse effects. HIV infection also alters the balance of CD4+ and CD8+ T cells in adipose tissue, with effects on macrophage activation and local inflammation, while the presence of latently infected CD4+ T cells in adipose tissue may constitute a protected viral reservoir. This review provides a synthesis of the literature on how HIV virus, ART treatment, and host characteristics interact to affect adipose tissue distribution, immunology, and contribution to metabolic health, and adipocyte maturation, cellular regulation, and energy storage. © 2017 American Physiological Society. Compr Physiol 7:1339-1357, 2017.

Cardiovascular risk and dyslipidemia among persons living with HIV: a review

BACKGROUND

Aim of this review is to focus the attention on people living with HIV infection at risk of developing a cardiovascular event. What is or what would be the most suitable antiretroviral therapy? Which statin or fibrate to reduce the risk? How to influence behavior and lifestyles?

DISCUSSION

Prevention of cardiovascular disease (CVD) risk remains the first and essential step in a medical intervention on these patients. The lifestyle modification, including smoking cessation, increased physical activity, weight reduction, and the education on healthy dietary practices are the main instruments. Statins are the cornerstone for the treatment of hypercholesterolemia. They have been shown to slow the progression or promote regression of coronary plaque, and could also exert an anti-inflammatory and immunomodulatory effect. However the current guidelines for the use of these drugs in general population are dissimilar, with important differences between American and European ones. The debate between American and European guidelines is still open and, also considering the independent risk factor represented by HIV, specific guidelines are warranted. Ezetimibe reduces the intestinal absorption of cholesterol. It is effective alone or in combination with rosuvastatin. It does not modify plasmatic concentrations of antiretrovirals. A number of experimental new classes of drugs for the treatment of hypercholesterolemia are being studied. Fibrates represent the first choice for treatment of hypertriglyceridemia, however, the renal toxicity of fibrates and statins should be considered. Omega 3 fatty acids have a good safety profile, but their efficacy is limited. Another concern is the high dose needed. Other drugs are acipimox and tesamorelin. Current antiretroviral therapies are less toxic and more effective than regimens used in the early years. Lipodistrophy and dyslipidemia are the main causes of long-term toxicities. Not all antiretrovirals have similar toxicities. Protease Inhibitors may cause dyslipidemia and lipodystrophy, while integrase inhibitors have a minimal impact on lipids profile, and no evidence of lipodystrophy. There is still much to be written with the introduction of new drugs in clinical practice.

CONCLUSIONS

Cardiovascular risk among HIV infected patients, interventions on behavior and lifestyles, use of drugs to reduce the risk, and switch in antiretroviral therapy, remain nowadays major issues in the management of HIV-infected patients.

Fat Matters: Understanding the Role of Adipose Tissue in Health in HIV Infection

More than one-third of adults in the USA are obese and obesity-related disease accounts for some of the leading causes of preventable death. Mid-life obesity may be a strong predictor of physical function impairment later in life regardless of body mass index (BMI) in older age, highlighting the benefits of obesity prevention on health throughout the lifespan. Adipose tissue disturbances including lipodystrophy and obesity are prevalent in the setting of treated and untreated HIV infection. This article will review current knowledge on fat disturbances in HIV-infected persons, including therapeutic options and future directions.

Obesity in patients with HIV infection: epidemiology, consequences and treatment options

Even though wasting used to characterize patients with HIV infection prior to the antiretroviral therapy (ART) era, obesity is becoming increasingly prevalent in this population. Areas covered: In the present review, we discuss the epidemiology, consequences and treatment options for obesity in patients with HIV infection. Expert commentary: Obesity exerts a multitude of detrimental cardiometabolic effects and appears to contribute to the increasing cardiovascular mortality of this population. However, there are very limited data on the optimal management of obesity in patients with HIV infection. Given the potential for interactions between antiobesity agents and ART that might compromise viral control, lifestyle changes should represent the cornerstone for the prevention and management of obesity in HIV infection.

Anatomic Fat Depots and Coronary Plaque Among Human Immunodeficiency Virus-Infected and Uninfected Men in the Multicenter AIDS Cohort Study

Methods. In a cross-sectional substudy of the Multicenter AIDS Cohort Study, noncontrast cardiac computed tomography (CT) scanning for coronary artery calcium (CAC) scoring was performed on all men, and, for men with normal renal function, coronary CT angiography (CTA) was performed. Associations between fat depots (visceral adipose tissue [VAT], abdominal subcutaneous adipose tissue [aSAT], and thigh subcutaneous adipose tissue [tSAT]) with coronary plaque presence and extent were assessed with logistic and linear regression adjusted for age, race, cardiovascular disease (CVD) risk factors, body mass index (BMI), and human immunodeficiency virus (HIV) parameters.

Results. Among HIV-infected men (n = 597) but not HIV-uninfected men (n = 343), having greater VAT was positively associated with noncalcified plaque presence (odds ratio [OR] = 1.04, P < .05), with a significant interaction (P < .05) by HIV serostatus. Human immunodeficiency virus-infected men had lower median aSAT and tSAT and greater median VAT among men with BMI <25 and 25–29.9 kg/m². Among HIV-infected men, VAT was positively associated with presence of coronary plaque on CTA after adjustment for CVD risk factors (OR = 1.04, P < .05), but not after additional adjustment for BMI. There was an inverse association between aSAT and extent of total plaque among HIV-infected men, but not among HIV-uninfected men. Lower tSAT was associated with greater CAC and total plaque score extent regardless of HIV serostatus.

Conclusions. The presence of greater amounts of VAT and lower SAT may contribute to increased risk for coronary artery disease among HIV-infected persons.

Lipolytic Rate Associated With Intramyocardial Lipid in an HIV Cohort Without Increased Lipolysis

CONTEXT

Individuals with HIV have an elevated risk for developing cardiovascular disease compared to controls, particularly in relationship to abnormal deposition of lipid within various body compartments. Dysregulation of lipolysis may contribute to abnormal deposition of lipid in non-adipose tissues such as the heart, leading to untoward health consequences.

OBJECTIVE

To evaluate potential relationships between rates of whole-body lipolysis and intramyocardial lipid content in HIV-infected subjects compared to healthy controls.

DESIGN

Cross-sectional study.

SETTING

National Institutes of Health Clinical Research Center in Bethesda, Maryland.

PARTICIPANTS

Forty-six HIV-infected adults and 12 controls without known cardiovascular disease.

MAIN OUTCOME MEASURE

Intramyocardial lipid content quantified by MRI and rates of lipolysis determined using stable isotope tracer techniques.

RESULTS

We observed a significant positive correlation between the rate of appearance of glycerol and intramyocardial lipid overall (r = 0.323; P = .014) and among the HIV group separately (r = 0.361; P = .014). Multivariate regression analyses including HIV, lipid-lowering therapy, and diabetes identified both rate of appearance of glycerol and age as independent significant predictors of intramyocardial lipid (P = .01 and P = .03, respectively), but these were not significant with inclusion of visceral adipose in the analyses.

CONCLUSIONS

To our knowledge, this study is among the first in humans to characterize the relationship between lipid deposition in the myocardium and direct measurement of whole-body fatty acid metabolism. Our current findings contribute to the growing understanding of factors that promote myocardial steatosis, such as visceral adiposity, and implicate lipolysis as a potential target for interventions to optimize myocardial health.

Increased pericardial fat accumulation is associated with increased intramyocardial lipid content and duration of highly active antiretroviral therapy exposure in patients infected with human immunodeficiency virus: a 3T cardiovascular magnetic resonance feasibility study

BACKGROUND

The aim of the current study was to examine whether the use of highly active antiretroviral therapy (HAART) in patients with HIV is associated with changes in pericardial fat and myocardial lipid content measured by cardiovascular magnetic resonance (CMR).

METHODS

In this prospective case-control study, we compared 27 HIV seropositive (+) male subjects receiving HAART to 22 control male subjects without HIV matched for age, ethnicity and body mass index. All participants underwent CMR imaging for determination of pericardial fat [as volume at the level of the origin of the left main coronary artery (LM) and at the right ventricular free wall] and magnetic resonance spectroscopy (MRS) for evaluation of intramyocardial lipid content (% of fat to water in a single voxel at the interventricular septum). All measurements were made by two experienced readers blinded to the clinical history of the study participants. Two-sample t-test, Spearman's correlation coefficient or Pearson's correlation coefficient and multivariable logistic regression were used for statistical analysis.

RESULTS

Pericardial fat volume at the level of LM origin was higher in HIV (+) subjects (33.4 cm(3) vs. 27.4 cm(3), p = 0.03). On multivariable analysis adjusted for age, Framingham risk score (FRS) and waist/hip ratio, pericardial fat remained significantly associated to HIV-status (OR 1.09, p = 0.047). For both HIV (+) and HIV (-) subjects, pericardial fat volume showed strong correlation with intramyocardial lipid content (r = 0.58, p < 0.0001) and FRS (r = 0.53, p = 0.0002). Among HIV (+) subjects, pericardial fat was significantly higher in patients with lipo-accumulation (37 cm(3) vs. 27.1 cm(3), p = 0.03) and showed significant correlation with duration of both HIV infection (r = 0.5, p = 0.01) and HAART (r = 0.46, p = 0.02).

CONCLUSIONS

Pericardial fat content is increased in HIV (+) subjects on chronic HAART (>5 years), who demonstrate HAART-related lipo-accumulation and prolonged HIV duration of infection. Further investigation is warranted to determine whether increased pericardial fat is associated with higher cardiovascular risk leading to premature cardiovascular events in this patient population.

Predictors of Treatment Response to Tesamorelin, a Growth Hormone-Releasing Factor Analog, in HIV-Infected Patients with Excess Abdominal Fat

BACKGROUND

Tesamorelin, a synthetic analog of human growth hormone-releasing factor, decreases visceral adipose tissue (VAT) in human immunodeficiency virus (HIV)-infected patients with lipodystrophy.

OBJECTIVES

1) To evaluate the utility of patient characteristics and validated disease-risk scores, namely indicator variables for the metabolic syndrome defined by the International Diabetes Federation (MetS-IDF) or the National Cholesterol Education Program (MetS-NCEP) and the Framingham Risk Score (FRS), as predictors of VAT reduction during tesamorelin therapy at 3 and 6 months, and 2) To explore the characteristics of patients who reached a threshold of VAT <140 cm2, a level associated with lower risk of adverse health outcomes, after 6 months of treatment with tesamorelin.

METHODS

Data were analyzed from two Phase 3 studies in which HIV-infected patients with excess abdominal fat were randomized in a 2:1 ratio to receive tesamorelin 2 mg (n = 543) or placebo (n = 263) subcutaneously daily for 6 months, using ANOVA and ANCOVA models.

RESULTS

Metabolic syndrome (MetS-IDF or MetS-NCEP) and FRS were significantly associated with VAT at baseline. Presence of metabolic syndrome ([MetS-NCEP), triglyceride levels >1.7 mmol/L, and white race had a significant impact on likelihood of response to tesamorelin after 6 months of therapy (interaction p-values 0.054, 0.063, and 0.025, respectively). No predictive factors were identified at 3 months. The odds of a VAT reduction to <140 cm2 for subjects treated with tesamorelin was 3.9 times greater than that of subjects randomized to placebo after controlling for study, gender, baseline body mass index (BMI) and baseline VAT (95% confidence interval [CI] 2.03; 7.44).

CONCLUSIONS

Individuals with baseline MetS-NCEP, elevated triglyceride levels, or white race were most likely to experience reductions in VAT after 6 months of tesamorelin treatment. The odds of response of VAT <140 cm2 was 3.9 times greater for tesamorelin-treated patients than that of patients receiving placebo.

The effect of physical activity on cardiometabolic health and inflammation in treated HIV infection

BACKGROUND

In HIV-uninfected populations, physical activity decreases mortality and inflammation. Inflammation is a potential cause of comorbidities in HIV+ adults, the evidence examining the effect of physical activity on cardiometabolic health is limited. This analysis examines the relationship between physical activity, cardiometabolic health and inflammation.

METHODS

We conducted a nested study within the SATURN-HIV trial in which 147 HIV+ adults were randomized to 10 mg daily rosuvastatin or placebo. Measures of physical activity, cardiometabolic health, inflammation and vascular disease (carotid artery intima media thickness and computed tomography-acquired measures pericardial fat volume) were assessed at baseline and through 96 weeks. Spearman correlations and multivariable analyses were used to explore relationships between physical activity, cardiometabolic health and inflammation.

RESULTS

Median age (Q1, Q3) was 46 (40.4, 52.7) years, 80% were male, 69% were African American and 46% were on protease inhibitors. Baseline median physical activity was 44 min per week (0, 150), 24% of participants performed greater than 150 min per week. At baseline, physical activity correlated with several markers of cardiometabolic health and inflammation (all P≤0.05). Over all time points median physical activity was independently associated with carotid distensibility (β=2.53; P=0.008), pericardial fat volume (β=-6.13; P=0.001) and interleukin-6 (β=-0.468; P<0.001).

CONCLUSIONS

Physical activity is associated with vascular disease, endothelial function, and may be an adjuvant to decreasing comorbidities in HIV+ adults. Further studies should examine long-term effects of physical activity on cardiometabolic health and inflammation in this population. Clinicaltrials.gov NCT01218802.

The association between alcohol use and cardiovascular disease among people living with HIV: a systematic review

BACKGROUND

People living with HIV-infection (PLWH) have higher prevalence and earlier onset of cardiovascular disease (CVD), compared to uninfected populations. It is unclear how alcohol consumption is related to CVD among PLWH.

OBJECTIVES

To summarize the current literature and strength of evidence regarding alcohol consumption as a risk factor for CVD among PLWH, to generate summary estimates for the effect of alcohol consumption on CVD outcomes, and to make recommendations for clinical practice and future research based on the findings and limitations of existing studies.

METHODS

A systematic review was conducted using Pubmed/Medline to identify relevant peer-reviewed articles published between 1 January 1999 and 1 January 2014. After critical review of the literature, 13 studies were identified. Risk ratios were extracted or calculated and sample size weighted summary estimates were calculated.

RESULTS

The prevalence of a CVD diagnosis or event ranged from 5.7-24.0%. The weighted pooled crude effect sizes were 1.75 (95% CI 1.06, 3.17) for general and 1.78 (95% CI 1.09, 2.93) for heavy alcohol use on CVD. The pooled adjusted effect size was 1.37 (95% CI 1.02, 1.84) for heavy alcohol use on CVD. Pooled estimates differed by CVD outcome and alcohol measure; alcohol consumption was most significant for cerebral/ischemic events.

CONCLUSION

HIV clinicians should consider risk factors that are not included in the traditional risk factor framework, particularly heavy alcohol consumption. Neglect of this risk factor may lead to underestimation of risk, and thus under-treatment among PLWH.

Abnormal Myocardial Function Is Related to Myocardial Steatosis and Diffuse Myocardial Fibrosis in HIV-Infected Adults

BACKGROUND

Impaired cardiac function persists in the era of effective human immunodeficiency virus (HIV) therapy, although the etiology is unclear. We used magnetic resonance imaging (MRI) to measure intramyocardial lipid levels and fibrosis as possible contributors to HIV-associated myocardial dysfunction.

METHODS

A cross-sectional study of 95 HIV-infected and 30 matched-healthy adults, without known cardiovascular disease (CVD) was completed. Intramyocardial lipid levels, myocardial fibrosis, and cardiac function (measured on the basis of strain) were quantified by MRI.

RESULTS

Systolic function was significantly decreased in HIV-infected subjects as compared to controls (mean radial strain [±SD], 21.7 ± 8.6% vs 30.5 ± 14.2%; P = .004). Intramyocardial lipid level and fibrosis index were both increased in HIV-infected subjects as compared to controls (P ≤ .04 for both) and correlated with the degree of myocardial dysfunction measured by strain parameters. Intramyocardial lipid levels correlated positively with antiretroviral therapy duration and visceral adiposity. Further, impaired myocardial function was strongly correlated with increased monocyte chemoattractant protein 1 levels (r = 0.396, P = .0002) and lipopolysaccharide binding protein levels (r = 0.25, P = .02).

CONCLUSIONS

HIV-infected adults have reduced myocardial function as compared to controls in the absence of known CVD. Decreased cardiac function was associated with abnormal myocardial tissue composition characterized by increased lipid levels and diffuse myocardial fibrosis. Metabolic alterations related to antiretroviral therapy and chronic inflammation may be important targets for optimizing long-term cardiovascular health in HIV-infected individuals.

HIV-1 Vpr induces adipose dysfunction in vivo through reciprocal effects on PPAR/GR co-regulation

Viral infections, such as HIV, have been linked to obesity, but mechanistic evidence that they cause adipose dysfunction in vivo is lacking. We investigated a pathogenic role for the HIV-1 accessory protein viral protein R (Vpr), which can coactivate the glucocorticoid receptor (GR) and co-repress peroxisome proliferator-activated receptor γ (PPARγ) in vitro, in HIV-associated adipose dysfunction. Vpr circulated in the blood of most HIV-infected patients tested, including those on antiretroviral therapy (ART) with undetectable viral load. Vpr-mediated mechanisms were dissected in vivo using mouse models expressing the Vpr transgene in adipose tissues and liver (Vpr-Tg) or infused with synthetic Vpr. Both models demonstrated accelerated whole-body lipolysis, hyperglycemia and hypertriglyceridemia, and tissue-specific findings. Fat depots in these mice had diminished mass, macrophage infiltration, and blunted PPARγ target gene expression but increased GR target gene expression. In liver, we observed blunted PPARα target gene expression, steatosis with decreased adenosine monophosphate-activated protein kinase activity, and insulin resistance. Similar to human HIV-infected patients, Vpr circulated in the serum of Vpr-Tg mice. Vpr blocked differentiation in preadipocytes through cell cycle arrest, whereas in mature adipocytes, it increased lipolysis with reciprocally altered association of PPARγ and GR with their target promoters. These results delineate a distinct pathogenic sequence: Vpr, released from HIV-1 in tissue reservoirs after ART, can disrupt PPAR/GR co-regulation and cell cycle control to produce adipose dysfunction and hepatosteatosis. Confirmation of these mechanisms in HIV patients could lead to targeted treatment of the metabolic complications with Vpr inhibitors, GR antagonists, or PPARγ/PPARα agonists.

Visceral adipose tissue as a source of inflammation and promoter of atherosclerosis

The current epidemic of obesity with the associated increasing incidence of insulin resistance, diabetes mellitus and atherosclerosis affecting a large proportion of the North American and Western populations, has generated a strong interest in the potential role of visceral adipose tissue in the development of atherosclerosis and its complications. The intra-abdominal and epicardial space are two compartments that contain visceral adipose tissue with a similar embryological origin. These visceral fats are highly inflamed in obese patients, patients with the metabolic syndrome and in those with established coronary artery disease; additionally they are capable of secreting large quantities of pro-inflammatory cytokines and free fatty acids. There is accumulating evidence to support a direct involvement of these regional adipose tissue deposits in the development of atherosclerosis and its complicating events, as will be reviewed in this article.

The association of visceral adiposity with cardiovascular events in patients with peripheral artery disease

BACKGROUND

Previous studies have suggested that patients with peripheral artery disease (PAD) suffer from a high incidence of cardiovascular events (CVE). Visceral adiposity has been implicated in promoting CVEs. This study aimed to assess the association of relative visceral adipose volume with incident cardiovascular events in patients with peripheral artery disease.

METHODS

This was a prospective cohort study including 260 patients with PAD who presented between 2003 and 2012. Cases were patients with diagnosed PAD including symptomatic lower limb athero-thrombosis and asymptomatic abdominal aortic aneurysm. All patients underwent computed tomography angiography (CTA). Abdominal visceral to total adipose volume ratio (relative visceral adipose volume) was estimated from CTAs using a previously validated workstation protocol. Cardiovascular risk factors were recorded at entry. The association of visceral adiposity with major CVEs (death, non-fatal myocardial infarction or stroke) was examined using Kaplan Meier and Cox proportional hazard analyses.

RESULTS

A total of 92 major CVEs were recorded in 76 patients during a median follow-up of 2.8 (IQR 1.2 to 4.8) years, including myocardial infarction (n = 26), stroke (n = 10) and death (n = 56). At 3 years the incidence of major CVEs stratified by relative visceral adipose volume quartiles were 15% [Quartile (Q) 1], 17% (Q2), 11% (Q3) and 15% (Q4) (P = 0.517). Relative visceral adipose volume was not associated with major CVEs after adjustment for other risk factors.

CONCLUSION

This study suggests that visceral adiposity does not play a central role in the predisposition for major CVEs in patients with PAD.

CD8 T-cell activation is associated with lipodystrophy and visceral fat accumulation in antiretroviral therapy-treated virologically suppressed HIV-infected patients

OBJECTIVE

HIV-infected patients receiving antiretroviral treatment frequently accumulate fat at the abdominal level. It is unknown whether T-cell activation and immune phenotypes are associated with fat accumulation. Thus, the aim of the study was to search for an association between the presence of clinical lipodystrophy (LD), visceral and subcutaneous abdominal adipose tissue amount (VAT and SAT), and peripheral T-cell immune phenotypes.

DESIGN

Cross-sectional study including 87 HIV-infected antiretroviral therapy-treated virologically suppressed and immune-reconstituted patients.

METHODS

The patients were evaluated for clinical LD, VAT, SAT, homeostasis model of insulin resistance, and coronary artery calcium score (>10). T-cell activation (CD8/CD38), differentiation (CD4/CD8/CCR7/CD45RA), and expression/activation of the interleukin-7 (IL-7)/IL-7R system (CD4/CD8/CD127, IL-7, and CD4/CD8/pStat-5) were assessed by cytometry.

RESULTS

In multivariable analyses, CD8 T-cell activation (CD38) was associated with lipoatrophy and central fat accumulation (respectively, β = 5.63, P = 0.005, and β = 4.19, P = 0.020). This was also the case for IL-7R expressing CD8⁺ T cells (CD127⁺) for lipoatrophy β = 12.8, P = 0.003, and for central fat accumulation β = 9.45, P = 0.016. CD8⁺ T-cell activation was also associated with VAT/total adipose tissue (β = 0.01, P = 0.002) and SAT/VAT ratios (β = -0.014, P = 0.015). As expected, VAT/total adipose tissue was an independent risk factor for homeostasis model of insulin resistance (r = 0.364, P = 0.028) and cardiovascular risk (coronary artery calcium, r = 0.406, P = 0.002).

CONCLUSIONS

CD8⁺ T-cell activation was associated with LD and the relative amount of VAT in antiretroviral therapy-controlled, virologically suppressed, HIV-infected patients. We propose that CD8 activation may be involved in the accumulation of central fat frequently observed in these patients, with resulting increased cardiometabolic risk.

Perivascular fat, inflammation, and cardiovascular risk in HIV-infected patients on antiretroviral therapy

BACKGROUND

HIV-infection is characterized by chronic immune activation that persists despite effective antiretroviral therapy (ART) and is associated with elevated cardiovascular risk. Whether specific perivascular fat depots are associated with inflammation in HIV is unknown.

METHODS

In a cross-sectional study, epicardial (EAT) and thoracic periaortic (TAT) adipose tissue volumes were measured by computed tomography in 100 HIV-infected adults, on stable ART, with LDL-cholesterol ≤130 mg/dL and evidence of heightened T-cell activation (CD8+CD38+HLA-DR+ ≥19%) or increased inflammation (high sensitivity C-reactive protein ≥2 mg/L).

RESULTS

Overall, 77% were males and 70% African American. Mean (standard deviation) age and body mass index were 47 (10) years and 28 (6.4) kg/m(2), respectively. All subjects had HIV-1 RNA <1000 copies/mL with mean (standard deviation) CD4+ T cell count of 665 (280) cells/μL; 50% were on a protease inhibitor. EAT and TAT were correlated with each other (r = 0.766, p < 0.0001). Both were associated with metabolic syndrome, atherogenic lipid profile, insulin resistance, total and central body fat, serum biomarkers of inflammation, and soluble CD163, but not with cellular immune activation markers. In multivariable models that adjusted for age, sex, and other measures of adiposity, both perivascular fat depots were independently associated with the presence of coronary calcium.

CONCLUSIONS

Perivascular fat is associated with soluble CD163, biomarkers of inflammation, insulin resistance, and subclinical atherosclerosis in this population of virologically suppressed HIV-infected patients on ART. The association of perivascular fat with coronary artery calcification appears to be independent of other measures of adiposity.

Adipose tissue and immune function: a review of evidence relevant to HIV infection

Human immunodeficiency virus type 1 (HIV) infection and antiretroviral therapy (ART) have long been associated with abnormalities in adipose tissue distribution and metabolism. More-recent evidence demonstrates that adipocytes and adipose-resident immune cells have a role in the response to HIV. Clinical and laboratory studies indicate that viral proteins and antiretroviral medications alter adipocyte biology to enhance the persistent, systemic inflammatory state characteristic of untreated and treated HIV infection. Relationships between body composition and lymphocyte populations, cellular immune activation, and immune reconstitution in HIV-infected individuals receiving ART suggest that adipose tissue may also affect cellular immune function. This is further supported by in vitro studies demonstrating the effect of adipocytes and adipokines on lymphocyte proliferation, differentiation, and activation. Synthesis of the literature on adipose tissue biology and immune function in uninfected individuals may shed light on major outstanding research questions in the HIV field.

Combined use of waist and hip circumference to identify abdominally obese HIV-infected patients at increased health risk

OBJECTIVES

To determine whether for a given waist circumference (WC), a larger hip circumference (HC) was associated with a reduced risk of insulin resistance, type 2 diabetes (T2D), hypertension and cardiovascular disease (CVD) in HIV-infected patients. A second objective was to determine whether, for a given WC, the addition of HC improved upon estimates of abdominal adiposity, in particular visceral adipose tissue (VAT), compared to those obtained by WC alone.

METHODS

HIV-infected men (N = 1481) and women (N = 841) were recruited between 2005 and 2009. WC and HC were obtained using standard techniques and abdominal adiposity was measured using computed tomography.

RESULTS

After control for WC and covariates, HC was negatively associated with risk of insulin resistance (p<0.05) and T2D [Men: OR = 0.91 (95% CI: 0.86-0.96); Women: OR = 0.91 (95% CI: 0.84-0.98)]. For a given WC, HC was also negatively associated with a lower risk of hypertension (p<0.05) and CVD [OR = 0.94 (95% CI: 0.88-0.99)] in men, but not women. Although HC was negatively associated with VAT in men and women after control for WC (p<0.05), the addition of HC did not substantially improve upon the prediction of VAT compared to WC alone.

CONCLUSIONS

The identification of HIV-infected individuals at increased health risk by WC alone is substantially improved by the addition of HC. Estimates of visceral adipose tissue by WC are not substantially improved by the addition of HC and thus variation in visceral adiposity may not be the conduit by which HC identifies increased health risk.

Impact of epicardial fat volume on coronary artery disease in symptomatic patients with a zero calcium score

BACKGROUND

This study sought to evaluate the prevalence of coronary artery disease (CAD) and the impact of epicardial fat volume (EFV) on CAD in symptomatic patients with a zero calcium score (CS) using multislice computed tomography (MSCT).

METHODS

In this study, 1308 consecutive symptomatic patients who underwent 64-slice MSCT with a zero CS were evaluated. EFV was quantified with CS data sets. Presence of an obstructive plaque (diameter stenosis >50%) and a CT-derived vulnerable plaque, which was defined as a plaque with remodeling index >1.10 and mean CT density value <3 0HU, was assessed with a CT coronary angiography.

RESULTS

Obstructive plaques were detected in 86 patients (7%) and CT-derived vulnerable plaques in 63 (5%). EFV was larger in patients with obstructive plaques than no plaque (124.3 ± 43.2 cm(3) vs. 95.1 ± 40.3 cm(3); p<0.01). Patients with CT-derived vulnerable plaques had a greater amount of EFV than no plaque (133.0 ± 40.2 cm(3) vs. 95.1 ± 40.3 cm(3); p<0.01). Multivariate analysis revealed EFV as a predictor of the presence of an obstructive and a CT-derived vulnerable plaque (per 10 cm(3); Odds ratio (OR) 1.10; 95% confidence interval (CI), 1.04-1.16; p<0.01 and OR 1.19; 95% CI, 1.12-1.27; p<0.01). The combination of EFV and Framingham risk score (FRS) resulted in an area under the receiver-operating characteristic curve for prediction of obstructive and CT-derived vulnerable plaque of 0.75 and 0.75, which was significantly higher than 0.68 and 0.64 for FRS alone (p=0.02 and p<0.01).

CONCLUSIONS

A zero CS doesn't exclude CAD and EFV can be a useful marker of CAD in symptomatic zero CS patients.