Epicardial adipose tissue and coronary artery calcium predict incident myocardial infarction and death in HIV-infected patients

Associations between epicardial, visceral, and subcutaneous adipose tissue with diastolic function in men with and without HIV

BACKGROUND

People with HIV (PWH) are at greater risk for diastolic dysfunction compared with persons without HIV (PWOH). An increase in visceral adipose tissue is common among PWH and greater visceral adipose tissue is associated with diastolic dysfunction among PWOH. We investigated associations of visceral adipose tissue, subcutaneous adipose tissue, and other fat depots with subclinical diastolic dysfunction among men with and without HIV (MWH and MWOH).

DESIGN

Cross-sectional analysis of MWH and MWOH in the Multicenter AIDS Cohort Study (MACS).

METHODS

Participants underwent echocardiography for diastolic dysfunction assessment and CT scanning including subcutaneous, visceral, epicardial, and liver adiposity measurements. Diastolic dysfunction was defined by characterizing heart function on antiretroviral therapy0 criteria. Odds for diastolic dysfunction with each measure of adiposity were estimated using multivariable logistic regression.

RESULTS

Among 403 participants (median age 57, 55% white, median BMI 26 kg/m 2 ), 25% met criteria for diastolic dysfunction and 59% MWH (82% undetectable plasma HIV RNA). Greater epicardial adipose tissue area was associated with higher odds of diastolic dysfunction [odds ratio:1.54 per SD; 95%confidence interval (CI) 1.15-2.05] when adjusted for demographics, HIV serostatus, and cardiovascular risk factors. This association did not differ by HIV serostatus and persisted when excluding MWH who were not virally suppressed. Less subcutaneous adipose tissue was associated with higher odds of diastolic dysfunction. Other adipose depots were not associated with diastolic dysfunction.

CONCLUSION

Greater epicardial adipose tissue and less subcutaneous adipose tissue were associated with diastolic dysfunction, regardless of HIV serostatus and viral suppression. Greater epicardial adipose tissue and less subcutaneous adipose tissue observed among PWH may contribute to risk for heart failure with preserved ejection fraction in this 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.

Epicardial Fat Volume as a Good Predictor for Multivessel Coronary Artery Disease

INTRODUCTION

Epicardial adipose tissue may have an important role in the pathogenesis of coronary artery disease (CAD).

AIM

We aimed to study the association between epicardial fat volume (EFV) and presence of obstructive as well as multivessel CAD.

METHODS

A total of 87 adult subjects with suspected CAD who underwent both quantified by multidetector computerized tomography (MDCT) and Invasive Coronary Angiography (ICA) were enrolled in this observational study. EVF was measured by MDCT by calculating the sum of cross- sectional areas of fat multiplied by slice thickness. EFV measurement and its association with the presence of obstructive CAD (defined as coronary artery stenosis > 70%) was evaluated.

RESULTS

Overall, 89.6% patients had obstructive CAD with higher EFV as compared to 10.3% patients with non-obstructive CAD (57 ± 20.14 cm3 vs. 44 ± 7.4 cm3; P < 0.001). Furthermore, EFV was significantly increased in group II as compared with group I (74 ± 24.3 ml vs. 53 ± 16.2 ml; P < 0.003). On the hand, the coronary calcium score (CAC) was insignificantly increased in group II as compared with group I (486.1 vs. 211.2; P = 0.10). Multivariate analysis revealed that, EFV might be an independent risk factor for not only the presence of obstructive CAD (odds ratio [OR], 1.062; 95% CI 1.018- 1.108; P < 0.005) but also in predicting multivessel disease affection.

CONCLUSIONS

Our results demonstrated that, EFV was significantly increased not only with obstructive CAD, independent of other traditional risk factors and CAC score, but also it can be considered a good predictor of multivessel disease occurrence.

Epicardial fat density, coronary artery disease and inflammation in people living with HIV

Studies have shown an increased risk of coronary artery disease (CAD) in the human immunodeficiency virus (HIV) population. Epicardial fat (EF) quality may be linked to this increased risk. In our study, we evaluated the associations between EF density, a qualitative characteristic of fat, and inflammatory markers, cardiovascular risk factors, HIV-related parameters, and CAD. Our study was cross-sectional, nested in the Canadian HIV and Aging Cohort Study, a large prospective cohort that includes participants living with HIV (PLHIV) and healthy controls. Participants underwent cardiac computed tomography angiography to measure volume and density of EF, coronary artery calcium score, coronary plaque, and low attenuation plaque volume. Association between EF density, cardiovascular risk factors, HIV parameters, and CAD were evaluated using adjusted regression analysis. A total of 177 PLHIV and 83 healthy controls were included in this study. EF density was similar between the two groups (-77.4 ± 5.6 HU for PLHIV and -77.0 ± 5.6 HU for uninfected controls, P = .162). Multivariable models showed positive association between EF density and coronary calcium score (odds ratio, 1.07, P = .023). Among the soluble biomarkers measured in our study, adjusted analyses showed that IL2Rα, tumor necrosis factor alpha and luteizing hormone were significantly associated with EF density. Our study showed that an increase in EF density was associated with a higher coronary calcium score and with inflammatory markers in a population that includes PLHIV.

Update in Human Immunodeficiency Virus and Aging

Effective and consistent antiretroviral therapy has enabled people with human immunodeficiency virus (HIV) (PWH) to survive longer than previously encountered earlier in the epidemic. Consequently, PWH are subject to the struggles and clinical conditions typically associated with aging. However, the aging process in PWH is not the same as for those who do not have HIV. There is a complex interplay of molecular, microbiologic, and pharmacologic factors that leads to accelerated aging in PWH; this leads to increased risk for certain age-related comorbidities requiring greater vigilance and interventions in routine care.

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.

Multimodality Imaging in HIV-Associated Cardiovascular Complications: A Comprehensive Review

Human immunodeficiency virus (HIV) infection is a leading cause of mortality and morbidity worldwide. The introduction of antiretroviral therapy (ART) has significantly reduced the risk of developing acquired immune deficiency syndrome and increased life expectancy, approaching that of the general population. However, people living with HIV have a substantially increased risk of cardiovascular diseases despite long-term viral suppression using ART. HIV-associated cardiovascular complications encompass a broad spectrum of diseases that involve the myocardium, pericardium, coronary arteries, valves, and systemic and pulmonary vasculature. Traditional risk stratification tools do not accurately predict cardiovascular risk in this population. Multimodality imaging plays an essential role in the evaluation of various HIV-related cardiovascular complications. Here, we emphasize the role of multimodality imaging in establishing the diagnosis and aetiopathogenesis of various cardiovascular manifestations related to chronic HIV disease. This review also provides a critical appraisal of contemporary data and illustrative cases.

High rate of left ventricular hypertrophy on screening echocardiography among adults living with HIV in Malawi

BACKGROUND

There are limited data on structural heart disease among people living with HIV in southern Africa, where the success of antiretroviral therapy (ART) has drastically improved life expectancy and where risk factors for cardiovascular disease are prevalent.

METHODS

We performed a cross-sectional study of screening echocardiography among adults (≥18 years) with HIV in Malawi presenting for routine ART care. We used univariable and multivariable logistic regression to evaluate correlates of abnormal echocardiogram.

RESULTS

A total of 202 individuals were enrolled with a median age of 45 years (IQR 39-52); 52% were female, and 27.7% were on antihypertensive medication. The most common clinically significant abnormality was left ventricular hypertrophy (LVH) (12.9%, n=26), and other serious structural heart lesions were rare (<2% with ejection fraction less than 40%, moderate-severe valve lesions or moderate-severe pericardial effusion). Characteristics associated with abnormal echocardiogram included older age (OR 1.04, 95% CI 1.01 to 1.08), higher body mass index (OR 1.09, 95% CI 1.02 to 1.17), higher mean systolic blood pressure (OR 1.03, 95% CI 1.02 to 1.05) and higher mean diastolic blood pressure (OR 1.03, 95% CI 1.01 to 1.05). In a multivariable model including age, duration on ART, body mass index, and systolic and diastolic blood pressure, only mean body mass index (adjusted OR 1.10, 95% CI 1.02 to 1.19), systolic blood pressure (aOR 1.05, 95% CI 1.03 to 1.08) and diastolic blood pressure (aOR 0.96, 95% CI 0.92 to 1.00) remained associated with abnormal echocardiogram.

CONCLUSIONS

LVH was common in this population of adults on ART presenting for routine care and was associated with elevated blood pressure. Further research is needed to characterise the relationship between chronic hypertension, LVH and downstream consequences, such as diastolic dysfunction and heart failure in people living with HIV.

Epicardial adipose tissue is a robust measure of increased risk of myocardial infarction - a meta-analysis on over 6600 patients and rationale for the EPIC-ACS study

BACKGROUND

Epicardial adipose tissue (EAT) surrounds the heart and the coronary vessels. EAT produces pro- and anti-inflammatory cytokines. Several studies have already documented the association of EAT and cardiovascular risk factors as well as coronary artery disease manifestations. Currently computed tomography (CT) is considered the gold standard for measurement of 3-dimensional volume of EAT. In addition, echocardiography might be an easy accessible alternative in particular in an emergency setting.

METHODS

We performed a metaanalysis of existing studies describing the differences of EAT in patients with and without myocardial infarction. We used established databases and were searching for "epicardial adipose tissue" or "pericardial adipose tissue" and "myocardial infarction", "coronary events", or "acute coronary syndrome". We included over 6600 patients from 7 studies. Random effect models were calculated and all analyses were performed by using the Review Manager 5.3.

RESULTS

Patients with myocardial infarction had 37% (confidence interval [0.21-0.54], P value <.001)] higher measures of EAT compared to patients without myocardial infarction. Comparing studies using echocardiography vs CT for assessment of EAT thickness, similar relative differences in EAT with wide overlap of confidence intervals were observed (for echocardiography: 0.4 [0.04-0.76], for CT: 0.36 [0.16-0.57], P value <.001 for both).

CONCLUSIONS

Patients with myocardial infarction have more EAT as compared to patients without myocardial infarction independently of the used imaging modality. Further prospective studies are needed to evaluate, how quantification of EAT in clinical routine can improve patients management.

Cardiovascular computed tomography and HIV: The evolving role of imaging biomarkers in enhanced risk prediction

The treatment of human immunodeficiency virus (HIV) with antiretroviral (ARV) medications has revolutionised the care for these patients. The dramatic increase in life expectancy has brought new challenges in treating diseases of aging in this cohort. Cardiovascular disease (CVD) is now a leading cause of morbidity and mortality with risk matched HIV-positive patients having double the risk of MI compared to HIV-negative patients. This enhanced risk is secondary to the interplay the virus (and accessory proteins), ARV medications and traditional risk factors. The culmination of these factors can lead to a hybrid metabolic syndrome characterised by heightened ectopic fat. Cardiovascular computed tomography (CT) is ideal for quantifying epicardial adipose tissue volumes, hepatosteatosis and cardiovascular disease burden. The CVD risk attributed to disease burden and plaque morphology is well established in general populations but is less clear in HIV populations. The purpose of this review article is to appraise the latest data on CVD development in HIV-positive patients and how the use of cardiovascular CT may be used to enhance risk prediction in this population. This may have important implications on individualised treatment decisions and risk reduction strategies which will improve the care of these patients.

Relationship between epicardial fat volume measured by multi-detector computed tomography and coronary artery disease

Background

The association between epicardial fat thickness and coronary artery disease (CAD) has been evaluated previously using echocardiography. Recently, multidetector computed tomography (MDCT), as a valuable tool in cardiovascular CT imaging, can improve characterization of CAD and give a more accurate volumetric quantitation of EF. The purpose of our study was to evaluate the relationship between the epicardial fat volume and CAD using multi-detector row CT.

Results

Out of the studied 120 patients, 22 patients were negative for CAD, while 98 patients had positive CAD. There was significant difference between both groups as regard epicardial fat volume (p < 0.001), and good relation was found between the amount of epicardial fat volume and coronary calcium score, number of affected vessel, plaque burden and degree of stenosis (p =  < 0.001).

Conclusion

EAT volume was larger in the presence of obstructive CAD and atheromatous plaques. These data suggest that EAT is associated with the development of coronary atherosclerosis and potentially the most dangerous types of plaques.

Association of epicardial fat with noncalcified coronary plaque volume and with low attenuation plaque in people with HIV

OBJECTIVES

People with HIV are exposed to a higher risk of coronary artery disease (CAD) compared with the general population. Epicardial fat may play a unique role in promoting coronary atherosclerosis. We measured epicardial fat in participants living with HIV and controls and investigated its association with coronary plaque volume and low attenuation plaque, a marker of plaque vulnerability.

DESIGN

This is a cross-sectional study, nested in the Canadian HIV and Aging Cohort Study, a large prospective cohort actively following participants with HIV and controls. Participants with low/intermediate cardiovascular risk without symptoms/history of CAD were invited to undergo cardiac computed tomography (CT).

METHODS

Volume of epicardial fat, coronary plaque and low attenuation component of the plaque were measured. Association between epicardial fat, coronary plaque volume and low attenuation component was tested using adjusted regression analysis.

RESULTS

A total of 169 participants with HIV and 81 controls underwent cardiac CT. Participants with HIV had a greater epicardial fat volume compared with controls (P = 0.019). In participants with HIV, epicardial fat volume was positively associated with duration of nonnucleoside reverse transcriptase inhibitors (NNRTI) (β=2.19, P = 0.004). After adjustment for cardiovascular risk factors, epicardial fat volume was positively associated to noncalcified plaque volume [odds ratio (OR) = 1.09, P = 0.028] and to the low-attenuation plaque component portion (β=0.38, P = 0.026).

CONCLUSION

The association of epicardial fat volume to noncalcified plaque volume and to low attenuation component plaque may suggest a potential mechanism by which epicardial fat could be a silent driver of CAD in the HIV population.

Detection of Subclinical Coronary Artery Lesions by Framingham Risk Score, Peripheral Artery Atheromatosis and Coronary Artery Calcium Score: A Pilot Study in Asymptomatic Individuals Living with HIV

The incidence of acute coronary events is increased among people living with HIV (PLWH), but there is no risk estimation score, nor a surrogate biomarker able to predict subclinical coronary artery disease (sCAD). We assessed the performance of: (i) Framingham risk score (FRMs), (ii) peripheral (carotid and femoral) artery atheromatosis, and (iii) coronary artery calcium (CACs) score, to detect the presence of sCAD, in PLWH. In a cohort of PLWH free of cardiovascular disease (CVD), we measured sCAD and CACs by computed tomography, calculated FRMs, and assessed carotid/femoral plaques by ultrasound. In 56 participants (age: 49 ± 10 years, men: 88%, FRMs: 7.2 ± 6.9; mean number of carotid/femoral plaques: 1.4 ± 1.5; CACs >0 present in 59%, median CACs 0.9 [IQR 0-22]): (i) minimal sCAD (stenosis 1%-24%; present in 30%) and mild sCAD (25%-49%, 25%) were effectively detected by FRMs, number of plaques, and CACs [area under the curve (AUC) of CACs was better than that of both FRM and plaques, p < .05]; (ii) moderate sCAD (stenosis 50%-69%; present in 8.9%) was detected by number of plaques and CACs, but similar AUC (0.969 vs. 0.867, respectively, p = NS); and (iii) severe sCAD (70%-99%, present in only 3 [5.4%]) was detected only by CACs. A high prevalence of sCAD in asymptomatic PLWH free of CVD was detected; CACs is a highly efficient biomarker to detect all grades of sCAD, however, the number of carotid/femoral plaques combined is also a very promising-lower cost and radiation free-surrogate biomarker. Future, larger studies are needed to verify these results.

Use of Coronary Artery Calcium Scoring to Improve Cardiovascular Risk Stratification and Guide Decisions to Start Statin Therapy in People Living With HIV

BACKGROUND

Cardiovascular disease (CVD) risk assessment remains a critical step in guiding decisions to initiate primary prevention interventions in people living with HIV (PLWH).

SETTING

We investigated whether coronary artery calcium (CAC) scoring allowed a more accurate selection of patients who may benefit from statin therapy, compared with current risk assessment tools alone.

METHODS

Cross-sectional analysis of PLWH over 50 years old who underwent CAC scoring between 2009 and 2019. Framingham Risk score (FRS), QRISK2 and D:A:D scores were calculated for each participant at the time of CAC scoring and statin eligibility determined based on current European guidelines on the prevention of CVD in PLWH.

RESULTS

A total of 739 patients were included (mean age 56 ± 5, 92.8% male, 84% white). Among 417 (56.4%) candidates for statin therapy based on FRS ≥10%, 174 (23.5%) had no detectable calcification (CAC = 0). Conversely, 145 (19.6%) patients with detectable calcification (CAC > 0) were identified as low-risk (FRS < 10%). When compared with FRS, CAC scoring reclassified CVD risk in 43.1% of patients, 145 (19.6%) to a higher risk group that could benefit from statin therapy and 174 (23.5%) statin candidates to a lower risk group. QRISK2 and D:A:D scores performed similarly to FRS, underestimating the presence of significant coronary calcification in 21.1% and 24.9% respectively and overestimating risk in 16.9% and 18.8% patients with CAC = 0.

CONCLUSIONS

Establishing a decision-model based on the combination of conventional risk tools and CAC scoring improves risk assessment and the selection of PLWH who would benefit from statin therapy.

Imaging modalities for cardiovascular phenotyping in asymptomatic people living with HIV

Cardiovascular disease (CVD) has emerged as a leading cause of non-HIV-related mortality among people living with HIV (PLWH). Despite the growing CVD burden in PLWH, there is concern that general population risk score models may underestimate CVD risk in these patients. Imaging modalities have received mounting attention lately to better understand the pathophysiology of subclinical CVD and provide improved risk assessment in this population. To date, traditional and well-established techniques such as echocardiography, pulse wave velocity, and carotid intima thickness continue to be the basis for the diagnosis and subsequent monitoring of vascular atherosclerosis and heart failure. Furthermore, novel imaging tools such as cardiac computed tomography (CT) and cardiac CT angiography (CCTA), positron emission tomography/CT (PET/CT), and cardiac magnetic resonance (CMR) have provided new insights into accelerated cardiovascular abnormalities in PLWH and are currently evaluated with regards to their potential to improve risk stratification.

Utility of routine non-gated CT chest in detection of subclinical atherosclerotic calcifications of coronary arteries in hospitalised HIV patients

OBJECTIVES

To evaluate coronary artery calcification (CAC) on routine CT chest in hospitalised HIV patients and to assess individual risk factors.

METHODS

Routine CT chests, May 2010-November 2015, of 143 hospitalised HIV-positive patients were reviewed for qualitative assessment of calcification in major coronary arteries by two radiologists. Presence, location and burden of calcification were evaluated on 3 mm axial images of CT chest. Cardiovascular risk factors and HIV lab parameters such as CD4 count, viral load and duration, and status of antiretroviral treatment were collected. Statistical analysis including multivariate logistic regression was performed.

RESULTS

Forty-one patients (28.7%) showed CAC, left anterior descending (n = 38, 92.7%), circumflex (n = 18, 43.9%) and Right Coronary Artery (n = 13, 31.7%); mostly mild CAC burden and mostly proximal left coronary arteries with excellent interobserver and intraobserver agreements (K = 0.9, and 1). Age of CAC+ group (53.9 years) was significantly higher than CAC- group (43.4, p < 0.001, minimum age of CAC+, 27 years). No significant difference between two groups in sex, ethnicity and risk factors and HAART status. CAC+ group showed significantly longer HIV duration (12.3 years vs 8.6, p < 0.0344) and higher CD4 cell counts (mean = 355.9 vs 175.3, p = 0.0053) and significantly lower viral load (76 vs 414K, p = 0.02) than CAC- group. On multivariate logistic regression, age, HIV duration and CD4 were significantly associated with CAC+ (p-values < .05).

CONCLUSIONS

One-third of hospitalised HIV patients showed subclinical CAC on CT chest. HIV duration and age of patients were independent risk factors for developing CAC. Higher CD4 cell count was strongly associated with CAC+.

ADVANCES IN KNOWLEDGE

Routine CT chest with or without contrast performed for non-cardiac indications is helpful in identification of subclinical CAC in HIV patients and radiologists should be encouraged to report CAC.CAC is seen in younger age group in HIV, and awareness of this finding on routine CT chest would help guiding clinicians to assess risk stratification for primary prevention of ischemic heart disease in this population at an earlier stage when compared to normal population.Duration of HIV infection and age of patients were independent risk factors for developing CAC in our study and CD4 count was strongly associated with presence of CAC.

18Fluoride-based molecular imaging of coronary atherosclerosis in HIV infected patients

BACKGROUND AND AIMS

Molecular imaging with ¹⁸Fluorodeoxyglucose (FDG) and ¹⁸F-sodium-fluoride (NaF) captures arterial inflammation and micro-calcification and can reveal potentially unstable atherosclerotic plaques.

METHODS

We performed FDG and NaF PET/CT imaging in two clinically similar cohorts of patients living with HIV (PLWH) with no symptomatic cardiovascular disease. The prevalence and intensity of coronary artery uptake of each tracer, measured as target-to-background ratio (TBR), were assessed in patients at low and high cardiovascular risk.

RESULTS

Ninety-three PLWH were submitted to PET/CT imaging with FDG (N = 43) and NaF (N = 50); 42% were at low and 58% at high cardiovascular risk. The intensity of uptake and multivessel coronary artery uptake were significantly higher with NaF than FDG both in low and high-risk patients. When each ¹⁸F-tracer was tested in low and high-risk patients, an equal proportion of subjects showed no vessel, single and multivessel NaF uptake; the same was true for no and single vessel uptake of FDG (no multivessel FDG uptake was noted). Waist circumference, CRP, D-dimer, HIV duration and treatment with nucleoside reverse transcriptase inhibitors were associated with high NaF uptake in univariable analyses; D-dimer remained significant in multivariable analyses (OR = 1.05; p=0.02). There were no significant associations with FDG uptake.

CONCLUSIONS

The prevalence of coronary artery uptake was higher with NaF compared to FDG both in high and low risk patients, hence microcalcification imaging may be a more sensitive tool to detect coronary atherosclerosis than inflammation imaging. However, the uptake of each ¹⁸Fluoride tracer was similar between low and high-risk subjects, and this underscores the discordance between clinical and imaging based risk assessment. Future investigation should address the prognostic significance of NaF coronary artery uptake.

HIV and pericardial fat are associated with abnormal cardiac structure and function among Ugandans

OBJECTIVES

To examine the relationship between pericardial fat (PCF) and cardiac structure and function among HIV-infected patients in the sub-Saharan African country of Uganda. People living with HIV (PLHIV) have altered fat distribution and an elevated risk for heart failure. Whether altered quantity and radiodensity of fat surrounding the heart relates to cardiac dysfunction in this population is unknown.

METHODS

One hundred HIV-positive Ugandans on antiretroviral therapy were compared with 100 age and sex-matched HIV-negative Ugandans; all were >45 years old with >1 cardiovascular disease risk factor. Subjects underwent ECG-gated non-contrast cardiac CT and transthoracic echocardiography with speckle tracking strain imaging. Multivariable linear and logistic regression models were used to explore the association of PCF with echocardiographic outcomes.

RESULTS

Median age was 55% and 62% were female. Compared with uninfected controls, PLHIV had lower body mass index (27 vs 30, p=0.02) and less diabetes (26% vs 45%, p=0.005). Median left ventricular (LV) ejection fraction was 67%. In models adjusted for traditional risk factors, HIV was associated with 10.3 g/m² higher LV mass index (LVMI) (95% CI 3.22 to 17.4; p=0.005), 0.87% worse LV global longitudinal strain (GLS) (95% CI -1.66 to -0.07; p=0.03) and higher odds of diastolic dysfunction (OR 1.96; 95% CI 0.95 to 4.06; p=0.07). In adjusted models, PCF volume was significantly associated with increased LVMI and worse LV GLS, while PCF radiodensity was associated with worse LV GLS (all p<0.05).

CONCLUSIONS

In Uganda, HIV infection, PCF volume and density are associated with abnormal cardiac structure and function.

Statins Reduce Epicardial Adipose Tissue Attenuation Independent of Lipid Lowering: A Potential Pleiotropic Effect

Background

High epicardial adipose tissue (EAT) attenuation (Hounsfield units [HUs]) on computed tomography is considered a marker of inflammation and is associated with an increased risk of cardiovascular events. Statins reduce the volume of EAT, but it is unknown whether they affect EAT HUs.

Methods and Results

We reviewed the chest computed tomographic scans of 420 postmenopausal women randomized to either 80 mg of atorvastatin or 40 mg of pravastatin daily and rescanned after 1 year to measure change in coronary artery calcium score. EAT HUs were measured near the proximal right coronary artery and remote from any area of coronary artery calcium. Computed tomographic images were also queried for subcutaneous adipose tissue (SubQ) attenuation (HUs) change over time. The mean patients’ age was 65±6 years. The baseline EAT HU value was higher than the SubQ HU value (−89.4±24.0 HU versus −123.3±30.4 HU; P<0.001). The EAT HU value decreased significantly in the entire cohort (−5.4±29.7 HU [−6% change]; P<0.001), but equally in the patients given atorvastatin and pravastatin (−6.35+31 HU and −4.55+28 HU; P=0.55). EAT HU change was not associated with change in total cholesterol, low‐density lipoprotein cholesterol, coronary artery calcium, and EAT volume (all P=not significant). Change in high‐density lipoprotein cholesterol was marginally associated with EAT HU change (P=0.07). Statin treatment did not induce a change in SubQ HUs.

Conclusions

Statins induced a decrease in EAT HUs over time, independent of intensity of low‐density lipoprotein cholesterol lowering. The positive effect on EAT and the neutral effect on SubQ suggest that statins induced a decrease in metabolic activity in EAT by reduction in cellularity, vascularity, or inflammation. The clinical significance of the observed change in EAT HUs remains to be demonstrated.

Molecular Imaging of Vascular Calcification with 18F-Sodium-Fluoride in Patients Infected with Human Immunodeficiency Virus

¹⁸F-Sodium Fluoride (NaF) accumulates in areas of active hydroxyapatite deposition and potentially unstable atherosclerotic plaques. We assessed the presence of atherosclerotic plaques in 50 adult patients with HIV (HIV+) who had undergone two cardiac computed tomography scans to measure coronary artery calcium (CAC) progression. CAC and its progression are predictive of an unfavorable prognosis. Tracer uptake was quantified in six arterial territories: aortic arch, innominate carotid artery, right and left internal carotid arteries, left coronary (anterior descending and circumflex) and right coronary artery. Thirty-one patients showed CAC progression and 19 did not. At least one territory with high NaF uptake was observed in 150 (50%) of 300 arterial territories. High NaF uptake was detected more often in non-calcified than calcified areas (68% vs. 32%), and in patients without than in those with prior CAC progression (68% vs. 32%). There was no correlation between clinical and demographic variables and NaF uptake. In clinically stable HIV+ patients, half of the arterial territories showed a high NaF uptake, often in the absence of macroscopic calcification. NaF uptake at one time point did not correlate with prior progression of CAC. Prospective studies will demonstrate the prognostic significance of high NaF uptake in HIV+ patients.

Noninvasive Cardiovascular Imaging: Emergence of a Powerful Tool for Early Identification of Cardiovascular Risk in People Living With HIV

Antiretroviral therapy (ART) has been pivotal in prolonging the lifespan of people living with HIV (PLWH). However, this also simultaneously increases their risk of cardiovascular disease (CVD) either related to ART, aging, hypertension, immunosenescence, inflammation, immune activation, or other comorbidities. Although the use of risk markers has greatly enhanced the field of cardiovascular (CV) medicine and improved the prognosis and early diagnosis in the general population, this strategy has not been clearly elucidated in PLWH. Developing accurate risk algorithms for PLWH requires an innate understanding of mechanistic factors influencing their risks. Early identification of CV risk will significantly enhance the prospects of PLWH living longer and relatively healthily. Herein, we discuss the use of multimodality noninvasive CV imaging as robust markers for ameliorating CV risk. The ability to prognosticate CV risk and hence prevent CV events in PLWH would represent an important advance in CV medicine, allowing precise detection and early institution of preventative strategies. Using novel CV imaging modalities and strategies would have a positive impact on precision medicine in this patient cohort.

Epicardial Adipose Tissue May Mediate Deleterious Effects of Obesity and Inflammation on the Myocardium

Epicardial adipose tissue has unique properties that distinguish it from other depots of visceral fat. Rather than having distinct boundaries, the epicardium shares an unobstructed microcirculation with the underlying myocardium, and in healthy conditions, produces cytokines that nourish the heart. However, in chronic inflammatory disorders (especially those leading to heart failure with preserved ejection fraction), the epicardium becomes a site of deranged adipogenesis, leading to the secretion of proinflammatory adipokines that can cause atrial and ventricular fibrosis. Accordingly, in patients at risk of heart failure with preserved ejection fraction, drugs that promote the accumulation or inflammation of epicardial adipocytes may lead to heart failure, whereas treatments that ameliorate the proinflammatory characteristics of epicardial fat may reduce the risk of heart failure. These observations suggest that epicardial adipose tissue is a transducer of the adverse effects of systemic inflammation and metabolic disorders on the heart, and thus, represents an important target for therapeutic interventions.

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.

Cardiovascular Disease in the Setting of Human Immunodeficiency Virus Infection

Background:

Since the introduction of Antiretroviral Therapy (ART), the life expectancy and health quality for patients infected with Human Immunodeficiency Virus (HIV) have significant-ly improved. Nevertheless, as a result of not only the deleterious effects of the virus itself and pro-longed ART, but also the effects of aging, cardiovascular diseases have emerged as one of the most common causes of death among these patients.

Objective:

The purpose of this review is to explore the new insights on the spectrum of Cardiovascu-lar Disease (CVD) in HIV infection, with emphasis on the factors that contribute to the atherosclerot-ic process and its role in the development of acute coronary syndrome in the setting of infection.

Methods:

A literature search using PubMed, ScienceDirect and Web of Science was performed. Ar-ticles up to Mar, 2017, were selected for inclusion. The search was conducted using MeSH terms, with the following key terms: [human immunodeficiency virus AND (cardiovascular disease OR coronary heart disease) AND (antiretroviral therapy AND (cardiovascular disease OR coronary heart disease))].

Results:

Clinical cardiovascular disease tends to appear approximately 10 years before in infected in-dividuals, when compared to the general population. The pathogenesis behind the cardiovascular, HIV-associated complications is complex and multifactorial, involving traditional CVD risk factors, as well as factors associated with the virus itself - immune activation and chronic inflammation – and the metabolic disorders related to ART regimens.

Conclusion:

Determining the cardiovascular risk among HIV-infected patients, as well as targeting and treating conditions that predispose to CVD, are now emerging concerns among physicians.

Prediction of hard cardiovascular events in HIV patients

OBJECTIVES

To assess the accuracy of risk prediction algorithms used in the general population and an HIV-specific algorithm to predict hard cardiovascular events.

METHODS

We compared the pooled equation algorithm (PE) proposed by the American Heart Association with the Framingham risk score (FRS) and the HIV-specific DAD (Data Collection on Adverse Effects of Anti-HIV Drugs) algorithm in a cohort of 2550 HIV+ patients followed for 17 337 patient-years.

RESULTS

During follow-up we recorded 67 myocardial infarctions and 2 cardiovascular deaths. PE and FRS identified and missed the same number of events (44 of 69 identified by PE and 49 of 69 by FRS). Similarly, DAD and FRS predicted and missed the same number of events (38 of 64 and 44 of 64 identified, respectively). All algorithms showed moderate sensitivity, specificity and positive predictive values, but high negative predictive values. However, PE and DAD identified more patients with no events than FRS (13.8% and 9.3% net reclassification improvement, respectively).

CONCLUSIONS

All algorithms showed a modest predictive ability, although the PE and DAD algorithms identified more patients at low risk.

Heart aging measured with coronary artery calcium scoring and cardiovascular risk assessment algorithms in HIV infected patients

ABTRACT Many sources have highlighted the high incidence of premature cardiovascular events in HIV infected patients. This raises the suspicion of an accelerated aging of the vascular system in this disease characterized by chronic systemic subliminal inflammation and immune dysregulation. Unfortunately all currently available risk assessment algorithms based on traditional risk factors, and even those containing more HIV-specific factors, fail to accurately predict risk in a large proportion of patients. In the general population several models have implemented imaging data to refine risk assessment, and the concept of vascular aging has been of value in improving the performance of these algorithms. It is expected that HIV patients may benefit from a similar approach as it becomes clearer that vascular imaging provides valuable prognostic information in this patient category.