The biology of atherosclerosis: general paradigms and distinct pathogenic mechanisms among HIV-infected patients

Inflammatory and Immune Mechanisms for Atherosclerotic Cardiovascular Disease in HIV

Atherosclerotic vascular disease disproportionately affects persons living with HIV (PLWH) compared to those without. The reasons for the excess risk include dysregulated immune response and inflammation related to HIV infection itself, comorbid conditions, and co-infections. Here, we review an updated understanding of immune and inflammatory pathways underlying atherosclerosis in PLWH, including effects of viral products, soluble mediators and chemokines, innate and adaptive immune cells, and important co-infections. We also present potential therapeutic targets which may reduce cardiovascular risk in PLWH.

Deficiency of Caspase-1 Attenuates HIV-1-Associated Atherogenesis in Mice

Within arterial plaque, HIV infection creates a state of inflammation and immune activation, triggering NLRP3/caspase-1 inflammasome, tissue damage, and monocyte/macrophage infiltration. Previously, we documented that caspase-1 activation in myeloid cells was linked with HIV-associated atherosclerosis in mice and people with HIV. Here, we mechanistically examined the direct effect of caspase-1 on HIV-associated atherosclerosis. Caspase-1-deficient (Casp-1-/-) mice were crossed with HIV-1 transgenic (Tg26+/-) mice with an atherogenic ApoE-deficient (ApoE-/-) background to create global caspase-1-deficient mice (Tg26+/-/ApoE-/-/Casp-1-/-). Caspase-1-sufficient (Tg26+/-/ApoE-/-/Casp-1+/+) mice served as the controls. Next, we created chimeric hematopoietic cell-deficient mice by reconstituting irradiated ApoE-/- mice with bone marrow cells transplanted from Tg26+/-/ApoE-/-/Casp-1-/- (BMT Casp-1-/-) or Tg26+/-/ApoE-/-/Casp-1+/+ (BMT Casp-1+/+) mice. Global caspase-1 knockout in mice suppressed plaque deposition in the thoracic aorta, serum IL-18 levels, and ex vivo foam cell formation. The deficiency of caspase-1 in hematopoietic cells resulted in reduced atherosclerotic plaque burden in the whole aorta and aortic root, which was associated with reduced macrophage infiltration. Transcriptomic analyses of peripheral mononuclear cells and splenocytes indicated that caspase-1 deficiency inhibited caspase-1 pathway-related genes. These results document the critical atherogenic role of caspase-1 in chronic HIV infection and highlight the implication of this pathway and peripheral immune activation in HIV-associated atherosclerosis.

High frequencies of adaptive NK cells are associated with absence of coronary plaque in cytomegalovirus infected people living with HIV

The objective of this study was to evaluate whether adaptive NKG2C+CD57+ natural killer (adapNK) cell frequencies are associated with pre-clinical coronary atherosclerosis in participants of the Canadian HIV and Aging Cohort Study. This cross-sectional study included 194 Canadian HIV and Aging Cohort Study participants aged ≥ 40 years of which 128 were cytomegalovirus (CMV)+ people living with HIV (PLWH), 8 were CMV-PLWH, 37 were CMV mono-infected individuals, and 21 were neither human immunodeficiency virus nor CMV infected. Participants were evaluated for the frequency of their adapNK cells and total plaque volume (TPV). TPV was assessed using cardiac computed tomography. Participants were classified as free of, or having, coronary atherosclerosis if their TPV was "0" and ">0," respectively. The frequency of adapNK cells was categorized as low, intermediate or high if they constituted <4.6%, between ≥4.6% and 20% and >20%, respectively, of the total frequency of CD3-CD56dim NK cells. The association between adapNK cell frequency and TPV was assessed using an adjusted Poisson regression analysis. A greater proportion of CMV+PLWH with TPV = 0 had high adapNK cell frequencies than those with TPV > 0 (61.90% vs 39.53%, P = .03) with a similar non-significant trend for CMV mono-infected participants (46.15% vs 34.78%). The frequency of adapNK cells was negatively correlated with TPV. A high frequency of adapNK cells was associated with a relative risk of 0.75 (95% confidence intervals 0.58, 0.97, P = .03) for presence of coronary atherosclerosis. This observation suggests that adapNK cells play a protective role in the development of coronary atherosclerotic plaques.

Cardiovascular risk factors and comorbidities in people living with HIV: A cross-sectional multicenter study from Colombia comorbidities in a Colombian PLWHIV population

INTRODUCTION

HIV is an independent risk factor for cardiovascular diseases (CVD). There is insufficient information regarding comorbidities and cardiovascular risk factors in the Colombian HIV population. The aim of this study is to describe the prevalence of cardiovascular risk factors and comorbidities in patients from the HIV Colombian Group VIHCOL.

METHODS

This is a multicenter, cross-sectional study conducted in the VIHCOL network in Colombia. Patients 18 years or older who had at least 6 months of follow-up were included. A stratified random sampling was performed to estimate the adjusted prevalence of cardiovascular risk factors and comorbidities.

RESULTS

A total of 1616 patients were included. 83.2% were men, and the median age was 34 years. The adjusted prevalence for dyslipidemia, active tobacco use, hypothyroidism, and arterial hypertension was 51.2% (99% CI: 48.0%-54.4%), 7.6% (99% CI: 5.9%-9.3%), 7.4% (99% CI: 5.7%-9.1%), and 6.3% (99% CI: 4.8%-7.9%), respectively.

CONCLUSIONS

In this Colombian HIV cohort, there is a high prevalence of modifiable CVD risk factors such as dyslipidemia and active smoking. Non-pharmacological and pharmacological measures for the prevention and management of these risk factors should be reinforced.

Assessment of coronary inflammation in antiretroviral treated people with HIV infection and active HIV/hepatitis C virus co-infection

OBJECTIVE

People with HIV (PWH) and co-infected with hepatitis C virus (PWH + HCV) have increased risk of cardiovascular disease (CVD). Peri-coronary inflammation, measured by fat attenuation index (FAI) on coronary computed tomography angiography (CCTA), independently predicts cardiovascular risk in the general population but has not been studied in the PWH + HCV population. We tested whether peri-coronary inflammation is increased in PWH or PWH + HCV, and whether inflammation changes over time.

DESIGN

Cross-sectional analysis to determine FAI differences among groups. Longitudinal analysis in PWH to assess changes in inflammation over time.

METHODS

Age-matched and sex-matched seropositive groups (PWH and PWH + HCV) virologically suppressed on antiretroviral therapy, HCV viremic, and without prior CVD and matched controls underwent CCTA. Peri-coronary FAI was measured around the proximal right coronary artery (RCA) and left anterior descending artery (LAD). Follow-up CCTA was performed in 22 PWH after 20.6-27.4 months.

RESULTS

A total of 101 participants (48 women) were studied (60 PWH, 19 PWH + HCV and 22 controls). In adjusted analyses, peri-coronary FAI did not differ between seropositive groups and controls. Low attenuation coronary plaque was significantly less common in seropositive groups compared with controls (LAD, P = 0.035; and RCA, P = 0.017, respectively). Peri-coronary FAI values significantly progressed between baseline and follow-up in PWH (RCA: P = 0.001, LAD: P = <0.001).

CONCLUSION

PWH and PWH + HCV without history of CVD do not have significantly worse peri-coronary inflammation, assessed by FAI, compared with matched controls. However, peri-coronary inflammation in mono-infected PWH significantly increased over approximately 22 months. FAI measures may be an important imaging biomarker for tracking asymptomatic CVD progression in PWH.

Mitochondrial Dynamics: Pathogenesis and Therapeutic Targets of Vascular Diseases

Vascular diseases, particularly atherosclerosis, are associated with high morbidity and mortality. Endothelial cell (EC) or vascular smooth muscle cell (VSMC) dysfunction leads to blood vessel abnormalities, which cause a series of vascular diseases. The mitochondria are the core sites of cell energy metabolism and function in blood vessel development and vascular disease pathogenesis. Mitochondrial dynamics, including fusion and fission, affect a variety of physiological or pathological processes. Multiple studies have confirmed the influence of mitochondrial dynamics on vascular diseases. This review discusses the regulatory mechanisms of mitochondrial dynamics, the key proteins that mediate mitochondrial fusion and fission, and their potential effects on ECs and VSMCs. We demonstrated the possibility of mitochondrial dynamics as a potential target for the treatment of vascular diseases.

COVID-19 and its effects on endothelium in HIV-positive patients in sub-Saharan Africa: Cardiometabolic risk, thrombosis and vascular function (ENDOCOVID STUDY)

BACKGROUND

COVID-19 has affected almost every country in the world, especially in terms of health system capacity and economic burden. People from sub-Saharan Africa (SSA) often face interaction between human immunodeficiency virus (HIV) infection and non-communicable diseases such as cardiovascular disease. Role of HIV infection and anti-retroviral treatment (ART) in altered cardiovascular risk is questionable and there is still need to further carry out research in this field. However, thus far it is unclear, what impact the COVID-19 co-infection in people living with HIV (PLHIV), with or without therapy will have. The ENDOCOVID project aims to investigate whether and how HIV-infection in COVID-19 patients modulates the time course of the disease, alters cardiovascular risk, and changes vascular endothelial function and coagulation parameters/ thrombosis risk.

METHODS

A total of 1026 patients will be included into this study. Cardiovascular research PLHIV with (n = 114 in each of the three recruiting centers) - or without - ART (n = 114 in each of the three recruiting centers) with COVID-19 and HIV-negative with COVID-19 (n = 114 in each of the three recruiting centers) will be carried out via clinical and biochemical measurements for cardiovascular risk factors and biomarkers of cardiovascular disease (CVD). Vascular and endothelial function will be measured by brachial artery flow-mediated dilatation (FMD), carotid intima-media thickness (IMT) assessments, and retinal blood vessel analyses, along with vascular endothelial biomarkers and cogualation markers. The correlation between HIV-infection in COVID-19 PLHIV with or without ART and its role in enhancement of cardiovascular risk and endothelial dysfunction will be assessed at admission, weekly, at discharge and, 4 weeks post-discharge (if possible).

IMPACT OF PROJECT

The ENDOCOVID project aims to evaluate in the long-term the cardiovascular risk and vascular endothelial function in PLHIV thus revealing an important transitional cardiovascular phenotype in COVID-19. The study was registered under clinicaltrials.gov (NCT04709302).

Cardiovascular effects of air pollution: current evidence from animal and human studies

Air pollution is a global health concern. Particulate matter (PM)_2.5, a component of ambient air pollution, has been identified by the World Health Organization as one of the pollutants that poses the greatest threat to public health. Cardiovascular health effects have been extensively documented, and these effects are still being researched to provide an overview of recent literature regarding air pollution-associated cardiovascular morbidity and mortality in humans. Additionally, potential mechanisms through which air pollutants affect the cardiovascular system are discussed based on human and additional animal studies. We used the strategy of a narrative review to summarize the scientific literature of studies that were published in the past 7 yr. Searches were carried out on PubMed and Web of Science using predefined search queries. We obtained an initial set of 800 publications that were filtered to 78 publications that were relevant to include in this review. Analysis of the literature showed significant associations between air pollution, especially PM_2.5, and the risk of elevated blood pressure (BP), acute coronary syndrome, myocardial infarction (MI), cardiac arrhythmia, and heart failure (HF). Prominent mechanisms that underlie the adverse effects of air pollution include oxidative stress, systemic inflammation, endothelial dysfunction, autonomic imbalance, and thrombogenicity. The current review underscores the relevance of air pollution as a global health concern that affects cardiovascular health. More rigorous standards are needed to reduce the cardiovascular disease burden imposed by air pollution. Continued research on the health impact of air pollution is needed to provide further insight.

HIV-related cardiovascular diseases: the search for a unifying hypothesis

Although the extensive rollout of antiretroviral (ARV) therapy resulted in a longer life expectancy for people living with human immunodeficiency virus (PLHIV), such individuals display a relatively increased occurrence of cardiovascular diseases (CVD). This health challenge stimulated significant research interests in the field, leading to an improved understanding of both lifestyle-related risk factors and the underlying mechanisms of CVD onset in PLHIV. However, despite such progress, the precise role of various risk factors and mechanisms underlying the development of HIV-mediated CVD still remains relatively poorly understood. Therefore, we review CVD onset in PLHIV and focus on 1) the spectrum of cardiovascular complications that typically manifest in such persons and 2) underlying mechanisms that are implicated in this process. Here, the contributions of such factors and modulators and underlying mechanisms are considered in a holistic and integrative manner to generate a unifying hypothesis that includes identification of the core pathways mediating CVD onset. The review focuses on the sub-Saharan African context, as there are relatively high numbers of PLHIV residing within this region, indicating that the greater CVD risk will increasingly threaten the well-being and health of its citizens. It is our opinion that such an approach helps point the way for future research efforts to improve treatment strategies and/or lifestyle-related modifications for PLHIV.

Anti-Inflammatory Interleukin 10 Inversely Relates to Coronary Atherosclerosis in Persons With Human Immunodeficiency Virus

Interleukin 10 (IL-10) is an anti-inflammatory cytokine that may be protective against coronary atherosclerosis. In an observational study of persons with human immunodeficiency virus (PWH) and uninfected controls, IL-10 was measured in serum samples by means of enzyme-linked immunosorbent assay, and coronary atherosclerosis was assessed using computed tomographic angiography. Among PWH, a 10-fold decrease in IL-10 was associated with a 2.6-fold increase in the odds of coronary plaque (P = .01), after controlling for traditional and nontraditional cardiovascular risk factors. IL-10 was also inversely associated with total coronary plaque (ρ = -0.19; P = .02) and noncalcified coronary plaque (ρ = -0.24; P = .004). Our findings suggest a role for IL-10 in mitigating atherosclerosis in PWH. Clinical Trials Registration. NCT00455793.

Risk of myocardial infarction among people living with HIV: an updated systematic review and meta-analysis

OBJECTIVE

Cardiovascular disease (CVD) is one of the leading non-AIDS-defining causes of death among HIV-positive (HIV+) individuals. However, the evidence surrounding specific components of CVD risk remains inconclusive. We conducted a systematic review and meta-analysis to synthesise the available evidence and establish the risk of myocardial infarction (MI) among HIV+ compared with uninfected individuals. We also examined MI risk within subgroups of HIV+ individuals according to exposure to combination antiretroviral therapy (ART), ART class/regimen, CD4 cell count and plasma viral load (pVL) levels.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews until 18 July 2018. Furthermore, we scanned recent HIV conference abstracts (CROI, IAS/AIDS) and bibliographies of relevant articles.

ELIGIBILITY CRITERIA

Original studies published after December 1999 and reporting comparative data relating to the rate of MI among HIV+ individuals were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers working in duplicate, independently extracted data. Data were pooled using random-effects meta-analysis and reported as relative risk (RR) with 95% CI.

RESULTS

Thirty-two of the 8130 identified records were included in the review. The pooled RR suggests that HIV+ individuals have a greater risk of MI compared with uninfected individuals (RR: 1.73; 95% CI 1.44 to 2.08). Depending on risk stratification, there was moderate variation according to ART uptake (RR, ART-treated=1.80; 95% CI 1.17 to 2.77; ART-untreated HIV+ individuals: 1.25; 95% CI 0.93 to 1.67, both relative to uninfected individuals). We found low CD4 count, high pVL and certain ART characteristics including cumulative ART exposure, any/cumulative use of protease inhibitors as a class, and exposure to specific ART drugs (eg, abacavir) to be importantly associated with a greater MI risk.

CONCLUSIONS

Our results indicate that HIV infection, low CD4, high pVL, cumulative ART use in general including certain exposure to specific ART class/regimen are associated with increased risk of MI. The association with cumulative ART may be an index of the duration of HIV infection with its attendant inflammation, and not entirely the effect of cumulative exposure to ART per se.

PROSPERO REGISTRATION NUMBER

CRD42014012977.

Blood pressure trajectories and the mediated effects of body mass index and HIV-related inflammation in a mixed cohort of people with and without HIV in rural Uganda

We sought to describe changes in blood pressure and estimate the effect of HIV on blood pressure (BP) over 4 years of observation in a cohort of 155 HIV-infected adults (≥40 years) on antiretroviral therapy (ART) and 154 sex- and age-quartile-matched, population-based, HIV-uninfected controls for four years in rural Uganda, we compared changes in blood pressure (BP) by HIV serostatus and tested whether body mass index and inflammation (high-sensitivity C-reactive protein and interleukin-6) and immune activation (sCD14 and sCD163) mediated the effects of HIV on BP using hierarchical multivariate and two-stage parametric regression models. Overall HIV-uninfected participants had higher mean BP than HIV-infected counterparts (differences in trend P < 0.0001 for diastolic BP and P = 0.164 for systolic BP). After initial declines in BP in both groups between years 1 and 2, BP moderately increased in both groups through year 4, with greater change over time observed in the HIV-uninfected group. Body mass index mediated 72% (95%CI 57, 97) of the association between HIV and systolic BP. We found a minimal mediating effect of sCD14 on the relationship between HIV and SBP (9%, 95% CI 5%, 21%), but found no association between other HIV-related biomarkers. Over four years of observation, HIV-infected people in rural Uganda have lower BP than HIV-uninfected counterparts despite having higher levels of inflammation. BMI, rather than measures of HIV-associated inflammation, explained a majority of the difference in BP observed.

Brief Report: Statin Effects on Myocardial Fibrosis Markers in People Living With HIV

BACKGROUND

In observational studies, patients with HIV have higher levels of soluble ST2 (sST2), galectin-3, and growth differentiation factor-15 (GDF-15) than non-HIV controls. As statins exert pleiotropic immunomodulatory effects that may affect markers of myocardial fibrosis, the objective of the current study is to determine whether biomarkers of myocardial fibrosis reflecting subclinical pathology may be modified by statin therapy in patients with HIV.

SETTING AND METHODS

Forty HIV+ men and women participated in a single center 12-month randomized, double-blind placebo-controlled trial of atorvastatin 40 mg every day vs. placebo. At baseline and 12-months, sST2, GDF-15, galectin-3 were measured.

RESULTS

The changes in sST2 were -0.310 (-4.195, 2.075) vs. 1.163 (0.624, 4.715) ng/mL, median (interquartile range) atorvastatin vs. placebo (P = 0.04). The change in sST2 was significantly related to changes in monocyte activation marker sCD14 (r = 0.63, P < 0.0001) and MCP (r = 0.52, P = 0.0009), markers of generalized inflammation hs-IL-6 (r = 0.58, P = 0.0002), oxLDL (r = 0.49, P = 0.002), and GDF-15 (r = 0.54, P = 0.0008).

CONCLUSIONS

sST2, a member of the IL-1 receptor family and a marker of fibrosis and inflammation increases over time among patients with HIV and this increase is attenuated by statin therapy in HIV. This effect may relate to immunomodulatory mechanisms of statins.

Inhibition of LPS-stimulated ecto-adenosine deaminase attenuates endothelial cell activation

Vascular inflammation is an important factor in the pathophysiology of cardiovascular diseases, such as atherosclerosis. Changes in the extracellular nucleotide and in particular adenosine catabolism may alter a chronic inflammation and endothelial activation. This study aimed to evaluate the relation between vascular ecto-adenosine deaminase (eADA) activity and endothelial activation in humans and to analyze the effects of LPS-mediated inflammation on this activity as well as mechanisms of its increase. Moreover, we investigated a therapeutic potential of ADA inhibition by deoxycofromycin (dCF) for endothelial activation. We demonstrated a positive correlation of vascular eADA activity and ADA1 mRNA expression with endothelial activation parameters in humans with atherosclerosis. The activation of vascular eADA was also observed under LPS stimulation in vivo along with endothelial activation, an increase in markers of inflammation and alterations in the lipid profile of a rat model. Ex vivo and in vitro studies on human specimen demonstrated that at an early stage of vascular pathology, eADA activity originated from activated endothelial cells, while at later stages also from an inflammatory infiltrate. We proposed that LPS-stimulated increase in endothelial adenosine deaminase activity could be a result of IL-6/JAK/STAT pathway activation, since the lack of IL-6 in mice was associated with lower vascular and plasma eADA activities. Furthermore, the inhibitors of JAK/STAT pathway decreased LPS-stimulated adenosine deaminase activity in endothelial cells. We demonstrated that cell surface eADA activity could be additionally regulated by transcytosis pathways, as exocytosis inhibitors including lipid raft inhibitor, methyl-β-cyclodextrin decreased LPS-induced eADA activity. This suggests that cholesterol-dependent protein externalization mediated by lipid rafts could be an important factor in the eADA increase. Moreover, endocytosis inhibitors and exocytosis activators increased this activity on the cell surface. Furthermore, the inhibition of adenosine deaminase in endothelial cells in vitro attenuated LPS-mediated IL-6 release and soluble ICAM-1 and VCAM-1 concentration in the incubation medium through the restoration of the extracellular adenosine pool and adenosine receptor-dependent pathways. This study demonstrated that the vascular endothelial eADA activity remains under control of inflammatory mediators acting through JAK/STAT pathway that could be further modified by dyslipidemic-dependent exocytosis and transcytosis pathways. Inhibition of eADA blocked endothelial activation suggesting a crucial role of this enzyme in the control of vascular inflammation. This supports the concept of eADA targeted vascular protection therapy.

Recurrence after hospitalization for acute coronary syndrome among HIV-infected and HIV-uninfected individuals

OBJECTIVES

We evaluated the association of HIV infection and immunodeficiency with acute coronary syndrome (ACS) recurrence, and with all-cause mortality as a secondary outcome, after hospitalization for ACS among HIV-infected and HIV-uninfected individuals.

METHODS

We conducted a retrospective cohort study within Kaiser Permanente Northern California of HIV-infected and HIV-uninfected adults discharged after ACS hospitalization [types: ST-elevation myocardial infarction (STEMI), non-STEMI, or unstable angina] during 1996-2010. We compared the outcomes of ACS recurrence and all-cause mortality within 3 years, both overall by HIV status and stratified by recent CD4 count, with HIV-uninfected individuals as the reference group. Hazard ratios (HRs) were obtained from Cox regression models with adjustment for age, sex, race/ethnicity, year, ACS type, smoking, and cardiovascular risk factors.

RESULTS

Among 226 HIV-infected and 86 321 HIV-uninfected individuals with ACS, HIV-infected individuals had a similar risk of ACS recurrence compared with HIV-uninfected individuals [HR 1.08; 95% confidence interval (CI) 0.76-1.54]. HIV infection was independently associated with all-cause mortality after ACS hospitalization overall (HR 2.52; 95% CI 1.81-3.52). In CD4-stratified models, post-ACS mortality was higher for HIV-infected individuals with CD4 counts of 201-499 cells/μL (HR 2.64; 95% CI 1.66-4.20) and < 200 cells/μL (HR 5.41; 95% CI 3.14-9.34), but not those with CD4 counts ≥ 500 cells/μL (HR 0.67; 95% CI 0.22-2.08), compared with HIV-uninfected individuals (P trend < 0.001).

CONCLUSIONS

HIV infection and immunodeficiency were not associated with recurrence of ACS after hospitalization. All-cause mortality was higher among HIV-infected compared with HIV-uninfected individuals, but there was no excess mortality risk among HIV-infected individuals with high CD4 counts.

Novel mediators of statin effects on plaque in HIV: a proteomics approach

OBJECTIVE

HIV patients have increased atherosclerotic coronary vascular disease (ASCVD), thought to be mediated through inflammatory mechanisms. We hypothesized that among asymptomatic HIV-infected patients with subclinical coronary plaque, statin therapy would modulate unique inflammatory and cardiovascular proteins in relation to change in subclinical coronary plaque volume. We tested this hypothesis using a novel proteomics approach.

DESIGN

Forty HIV-infected participants were randomized to atorvastatin (40 mg/day) versus placebo, and underwent computed tomography coronary angiography to quantify plaque volume at baseline and 1 year.

METHODS

We used Olink Cardiovascular III and Cardiometabolic panels based on dual antibody epitope recognition with linked DNA amplification to compare change over time in 184 proteins in treatment versus placebo and in relation to change in coronary plaque volume.

RESULTS

Six proteins (TFPI, CCL24, NT-Pro BNP, MBL2, LTBR, PCOLCE) changed significantly in the atorvastatin versus placebo group, many in innate immune and other novel inflammatory pathways. Twenty-six proteins changed significantly in relationship to total coronary plaque volume over 1 year. Notably, many of these proteins changed only weakly in relationship to change in low-density lipoprotein (LDL). Overlapping these two broad discovery approaches, proteins involved in myocardial fibrosis/collagen formation and monocyte chemoattraction changed with statin treatment, in relationship to plaque volume, but not LDL.

CONCLUSION

This proof-of-concept study employing a proteomic discovery platform offers insight into statin effects on novel immune pathways relevant to ASCVD progression in HIV. Novel biomarker discovery may enhance precision medicine strategies to estimate the efficacy of targeted therapies to reduce ASCVD progression and events in HIV.

Human Immunodeficiency Virus Infection And Hypertension. Is There a Connection?

Data support that hypertension (HTN) is prevalent among human immunodeficiency virus (HIV) patients contributing to increased risk of cardiovascular disease. Immunodeficiency and prolonged antiretroviral treatment along with common risk factors including older age, male gender, and high body mass index might conduce to greater incidence of HTN. The purpose of this review was to summarize recent evidence of the increased cardiovascular risk in these patents linking HIV infection to HTN.

HIV infection and stroke

The landscape of human immunodeficiency virus (HIV) infection is changing with the increasing coverage of antiretroviral therapy (ART). Patients are living longer but continually exposed to a virologically suppressed HIV infection. This has resulted in a decrease in acquired immune deficiency syndrome (AIDS)-related complications such as opportunistic infections, and an increase in non-AIDS complications such as stroke. In this era, stroke is perhaps the most important neurologic complication of HIV infection. Furthermore, stroke is more of a heterogeneous disease in people living with HIV infection and therefore needs to be approached systematically. Many of the etiologies are treatable. HIV-associated vasculopathy is perhaps the most common etiology in this population and our understanding of this is still evolving. Moreover, the treatment of HIV infection may contribute to an excess risk of stroke and interact with stroke therapies.

Factors associated with high cardiovascular risk in a primarily African American, urban HIV-infected population

Objective:

To determine factors associated with increased risk of developing cardiovascular disease in a high-risk patient population.

Design:

Cross-sectional analysis of a retrospective cohort study.

Methods:

One-hundred patients at an inner city HIV clinic in 2008 were reviewed. The atherosclerotic vascular disease risk score was calculated using the Pooled Cohort Equation. Chi-square test was performed to identify associations of potential risk factors with elevated atherosclerotic vascular disease risk.

Results:

Eighty-one participants were included in the final analysis. In total, 95.1% were African American, and 38.3% were women. The median atherosclerotic vascular disease risk score was 8.8% and 8.1% in 2008 and 2012, respectively. The medical co-morbidities associated with increased atherosclerotic vascular disease risk were hepatitis C infection (X² = 3.93; p value = 0.048), elevated triglycerides levels (X² = 4.0; p value = 0.046), and low albumin (X² = 4.65; p value = 0.031). There were a higher number of women with known atherosclerotic vascular disease despite lower median atherosclerotic vascular disease risk score compared to men.

Conclusion:

An elevated risk of developing cardiovascular disease persists in high-risk demographic groups of the HIV epidemic even in the current HIV era. There is an unexplained gender disparity and some non-traditional risk factors not accounted for in the Pooled Cohort Equation may be contributing to the excess cardiovascular disease risk observed among HIV-infected patients.

A histomorphometric study on the effects of antiretroviral therapy (ART) combined with a high-calorie diet (HCD) on aortic perivascular adipose tissue (PVAT)

Perivascular adipose tissue (PVAT), surrounding arteries is metabolically active. Obesity and antiretroviral therapy (ART) may cause pathophysiological conditions in the aortic wall and surrounding PVAT. The aim of the study was to determine the histological effects on the aortic wall, aortic PVAT adipocyte morphology and leptin staining intensity in obese rats treated with ART. Wistar rats (N=36) were divided into four groups; a lean control (C/ART-), ART control (C/ART+), high-calorie diet (HCD) untreated (HCD/ART-) and HCD and ART experimental (HCD/ART+). The aorta and surrounding PVAT were stained with haematoxylin and eosin (H&E) and anti-leptin antibodies for immunohistochemistry (IHC). The C/ART+ group had a thinner tunica media compared to the HCD/ART- group. The tunica adventitia was thicker in the ART groups (C/ART+ and HCD/ART+) compared to the lean control group. White adipocytes in the HCD/ART- group was larger in size compared to the other three groups. The high-calorie diet groups (HCD/ART- and HCD/ART+) had increased adipocyte sizes, for both brown and differentiating adipocytes, compared to the control groups (C/ART- and C/ART+). The unilocular and differentiating adipocytes in the C/ART+ group showed intense leptin staining. Unilocular and differentiating adipocytes in the HCD/ART- and HCD/ART+ groups showed weak to no leptin staining intensity. The present study indicated that ART and a HCD, separately and combined, altered both the tunica media and adventitia of the aortic wall, whereas the HCD alone caused adipocytes to increase in size. The leptin staining intensity suggested that ART alone may lead to increased leptin expression, whereas ART combined with a HCD may cause leptin deficiency. Changes seen with ART in a rat model suggest that aortic wall thickness and PVAT adipocyte morphology alterations should be considered by clinicians in obese individuals receiving ART.

Comparison of the Peripheral Reactive Hyperemia Index with Myocardial Perfusion Reserve by 82Rb PET/CT in HIV-Infected Patients

After the introduction of antiretroviral therapy (ART) the life expectancy of patients infected with human immunodeficiency virus (HIV) is now approaching that of the general population and the importance of non-AIDS co-morbidities is increasing. Specifically, the risk of coronary artery disease (CAD) seems to be higher in HIV-infected patients and an accurate risk prediction of CAD is of high importance for optimal long term treatment. In this study, we assessed the correlation of the endoPAT, which is an office-based CVD screening tool with the myocardial perfusion reserve by ⁸²-rubidium PET/CT. We measured the reactive hyperemia index, which is a measure of the endothelial responsiveness, by the use of an endoPAT device (Itamar Medical, Caesarea, Israel) in 48 ART treated HIV-infected patients with high CD 4 cell counts and viral suppression (HIV-RNA < 20 copies/mL), who had previously undergone measurement of the myocardial perfusion reserve by ⁸²-rubidium PET/CT for study purposes. We found an inverse correlation between the reactive hyperemia index and the myocardial perfusion reserve which most likely indicates different vascular physiology. This study did not find evidence to suggest the immediate implementation of the reactive hyperemia index as a screening tool for early coronary artery disease in well-treated HIV-infected patients pending further validation in larger prospective studies.

Cardiovascular Disease, Statins, and HIV

Human immunodeficiency virus (HIV)-infected patients are at an increased risk of serious, non-AIDS-defining comorbidities, even in the setting of viral suppression with combination antiretroviral therapy. This increased risk is due in part to immune dysfunction and heightened inflammation and immune activation associated with chronic HIV infection. Statins have wide-reaching immunomodulatory effects, and their use in the HIV-infected population may be of particular benefit. In this article, we review the pathogenesis of increased inflammation during HIV infection and how it contributes to the risk of cardiovascular disease among HIV-infected individuals. We then we review the immunomodulatory effects of statins and how they may attenuate the risk of cardiovascular disease and other comorbidities in this unique patient population.

Lower coronary plaque burden in patients with HIV presenting with acute coronary syndrome

OBJECTIVE

Treated HIV infection is associated with a higher incidence of coronary artery disease and myocardial infarction, although the mechanisms remain unclear. We sought to characterise the burden of coronary artery disease in men with HIV using retrospective data from invasive coronary angiograms in patients presenting with acute coronary syndrome (ACS).

METHODS

Demographic and coronary angiographic data were obtained from 160 men with ST elevation myocardial infarction, non-STEMI or high-risk chest pain; 73 HIV-infected cases and 87 age-matched controls. The burden of coronary disease was calculated using the Gensini Angiographic Scoring System by 2 independent cardiologists blinded to HIV status.

RESULTS

The 2 groups were matched for age, sex and cardiac event subtype and there was no difference in rates of smoking or cholesterol levels. Compared with control participants, patients with HIV had higher usage of antihypertensives (46 (63%) vs 30 (35%), p<0.001) and statins (47 (64%) vs 29 (33%), p<0.001). There was no difference in plaque distribution between both groups; however, the Gensini score was 42% lower in cases with HIV than in controls (p<0.03). C reactive protein was higher in cases with HIV (13.4±15.4 vs 3.7±3.6).

CONCLUSIONS

Men with HIV presenting with ACS paradoxically had a lower burden of coronary plaque than matched controls, despite more aggressive risk factor management, suggesting that plaque vulnerability, rather than total burden of atherosclerosis, may be important in the pathophysiology of coronary artery disease in men with HIV.

Associations between antiretroviral use and subclinical coronary atherosclerosis

OBJECTIVES

HIV infection is associated with increased prevalence of subclinical coronary plaque. The extent to which such plaque reflects effects of HIV infection or effects of long-term antiretroviral therapy (ART) use remains unclear and was the goal of this analysis.

DESIGN AND METHODS

We compared the prevalence and extent of coronary plaque and stenosis between users of specific ART drugs or drug classes using coronary computed tomography (CT) among HIV-infected men in the Multicenter AIDS Cohort Study. To account for time-dependent confounders, including cardiovascular disease risk factors and time-varying reasons for using specific treatments, we conducted fully adjusted logistic and linear models with inverse probability of treatment weighting.

RESULTS

There were 618 men who underwent noncontrast coronary CT; 450 also underwent coronary CT angiography. At the time of scanning, 81% had undetectable plasma HIV RNA. In fully adjusted models, cumulative use of zidovudine, abacavir, darunavir, and protease inhibitors as a drug class were inconsistently associated with specific forms of plaque presence or extent.

CONCLUSION

Among virally suppressed HIV-infected men with extensive ART exposure, no consistent associations between use of specific ART drugs and both subclinical coronary plaque presence and extent were apparent. Our findings support the hypothesis that, among virally suppressed persons, type of ART used is not in general a major determinant of subclinical coronary plaque risk.

Use of Abacavir and Risk of Cardiovascular Disease Among HIV-Infected Individuals

BACKGROUND

Evidence is conflicting about the association of abacavir use and cardiovascular disease (CVD) among HIV-infected individuals. Previous studies may have been biased by the preferential initiation or continuation of abacavir in patients with renal dysfunction.

METHODS

We conducted a cohort study in Kaiser Permanente California during 1998-2011, following HIV-infected adults initiating antiretroviral therapy until the earliest of CVD (ie, coronary heart disease or ischemic stroke), health plan disenrollment, death, or end of study. We used inverse-probability weighting to fit marginal structural models to estimate hazard ratios (HRs) for CVD comparing regimens with and without abacavir. Propensity score models included demographics, HIV-specific factors, and CVD risk factors, including alcohol/drug use, smoking, overweight/obesity, diabetes, lipid-lowering and hypertension therapy, and renal dysfunction (ie, estimated glomerular filtration rate <60 mL·min·1.73 m).

RESULTS

Among 8154 subjects, 178 had ≥1 CVD event, with 24/704 (3.4%) in the abacavir group and 154/7450 (2.1%) in the group initiating regimens without abacavir. Abacavir users had more renal dysfunction at antiretroviral therapy initiation (7.0% vs. 3.3%, P < 0.001). Compared with patients initiating regimens without abacavir, abacavir users had a 2.2-fold higher risk of CVD in intention-to-treat analysis [HR 2.2, 95% confidence interval (CI): 1.4 to 3.5], a 2.7-fold higher risk when remaining on their initial regimens for ≥1 year (HR 2.7, 95% CI: 1.5 to 5.0), and a 2.1-fold higher risk in per-protocol analysis (HR 2.1, 95% CI: 0.9 to 5.0).

CONCLUSIONS

Abacavir was associated with an over 2-fold increased risk of CVD, which was not explained by renal dysfunction or other CVD risk factors.

Contribution of antiretroviral therapy to cardiovascular disease risk in HIV-infected patients

Rates of cardiovascular disease (CVD) are over twice as high in HIV-infected compared with uninfected patients, and this excess risk could be due to the effect of antiretroviral medications (ARVs) but the data regarding this are mixed. We described the literature on associations reported between classes and individual ARVs and rates of CVD and to changes in surrogate markers of subclinical CVD. Many PIs and certain NRTIs contribute to the development of CVD though recent generations of PIs appear to have less effect on development of CVD as assessed by surrogate measures of subclinical CVD. Future antiretroviral drug development efforts should include surrogate measures of subclinical cardiovascular to minimize the potential contributions of new ARVs to subclinical or clinical CVD.

Prevalence of aortic valve dystrophy and insufficiency in a cohort of 255 HIV-positive patients followed-up in a cardiology department between 2012 and 2014

OBJECTIVES

To study valve appearance and the presence of valve disease in a cohort of people living with HIV (PLHIV).

DESIGN

A prospective study of PLHIV examined at the cardiology department of the Clermont Ferrand university hospital group (CHU) between January 1, 2012, and December 31, 2014. Were excluded those with a history of infection associated with a possible endocarditis.

METHODS

Demographic, medical characteristics and cardiovascular disease risk factors at time of cardiovascular examination and Doppler-echocardiography were recorded and analyzed.

RESULTS

In total, 903 PLHIV were examined in the infectious diseases department, 255 of whom were included. These consisted of 67 women (26.3%) and 188 men, of a mean age of 51.2±9.7years, in whom coronary artery disease was diagnosed in 18 patients (7.0%), two women and 16 men, representing a prevalence of 3.0% in females and 8.5% in males. The appearance of the aortic cusps was considered dystrophic in 14.1% of cases (36/255), dysplastic in two cases (0.8%), exhibiting a bicuspid deformity in one case. The prevalence of aortic valve abnormality was therefore 6.0% in the women (4/67) and 17.0% in the men (32/188). On facing off this data with the Kora Monica study findings, an increase in prevalence appears only to truly manifest after 50years of age. We registered 35 aortic insufficiency cases (13.7%), representing a higher incidence than that of the Framingham cohort, with age and masculine gender being the determining factors.

CONCLUSION

Valve disease, along with coronary artery disease, should be closely monitored in PLHIV.

Inflammation, immune activation, and cardiovascular disease in HIV

Cardiovascular disease is one of the leading causes of morbidity and mortality in people living with HIV. Several epidemiological studies have shown an increased risk of myocardial infarction and stroke compared to uninfected controls. Although traditional risk factors contribute to this increased risk of cardiovascular disease, HIV-specific mechanisms likely also play a role. Systemic inflammation has been linked to cardiovascular disease in several populations suffering from chronic inflammation, including people living with HIV. Although antiretroviral therapy reduces immune activation, levels of inflammatory markers remain elevated compared to uninfected controls. The causes of this sustained immune response are likely multifactorial and incompletely understood. In this review, we summarize the evidence describing the relationship between inflammation and cardiovascular disease and discuss potential anti-inflammatory treatment options for cardiometabolic disease in people living with HIV.

Infectious and Non-infectious Etiologies of Cardiovascular Disease in Human Immunodeficiency Virus Infection

Background:

Increasing rates of HIV have been observed in women, African Americans, and Hispanics, particularly those residing in rural areas of the United States. Although cardiovascular (CV) complications in patients infected with human immunodeficiency virus (HIV) have significantly decreased following the introduction of antiretroviral therapy on a global scale, in many rural areas, residents face geographic, social, and cultural barriers that result in decreased access to care. Despite the advancements to combat the disease, many patients in these medically underserved areas are not linked to care, and fewer than half achieve viral suppression.

Methods:

Databases were systematically searched for peer-reviewed publications reporting infectious and non-infectious etiologies of cardiovascular disease in HIV-infected patients. Relevant articles cited in the retrieved publications were also reviewed for inclusion.

Results:

A variety of outcomes studies and literature reviews were included in the analysis. Relevant literature discussed the manifestations, diagnosis, treatment, and outcomes of infectious and non-infectious etiologies of cardiovascular disease in HIV-infected patients.

Conclusion:

In these medically underserved areas, it is vital that clinicians are knowledgeable in the manifestations, diagnosis, and treatment of CV complications in patients with untreated HIV. This review summarizes the epidemiology and causes of CV complications associated with untreated HIV and provide recommendations for management of these complications.

Atherosclerosis is Evident in Treated HIV-Infected Subjects With Low Cardiovascular Risk by Carotid Cardiovascular Magnetic Resonance

OBJECTIVE

Premature atherosclerosis has been observed among HIV-infected individuals with high cardiovascular risk using one-dimensional ultrasound carotid intima-media thickness. We evaluated the assessment of HIV-infected individuals with low traditional cardiovascular disease risk using cardiovascular magnetic resonance, which allows three-dimensional assessment of the carotid artery wall.

METHODS

Carotid cardiovascular magnetic resonance was performed in 33 HIV-infected individuals (cases) (19 male, 14 female), and 35 HIV-negative controls (20 male, 15 female). Exclusion criteria included smoking, hypertension, hyperlipidemia (total cholesterol/HDL ratio > 5) or family history of premature atherosclerosis. Cases were stable on combination antiretroviral therapy with plasma HIV-1 RNA <50 copies per milliliter. Using computer modeling, the arterial wall, lumen, and total vessel volumes were calculated for a 4-cm length of each carotid artery centered on the bifurcation. The wall/outer-wall ratio (W/OW), an index of vascular thickening, was compared between the groups.

RESULTS

Cases had a median CD4 cell count of 690 cells per microliter. Mean (±SD) age and 10-year Framingham coronary risk scores were similar for cases and controls (45.2 ± 9.7 years versus 46.9 ± 11.6 years and 3.97% ± 3.9% versus 3.72% ± 3.5%, respectively). W/OW was significantly increased in cases compared with controls (36.7% versus 32.5%, P < 0.0001); this was more marked in HIV-infected females. HIV status was significantly associated with increased W/OW after adjusting for age (P < 0.0001). No significant association between antiretroviral type and W/OW was found-W/OW lowered comparing abacavir to zidovudine (P = 0.038), but statistical model fits poorly.

CONCLUSIONS

In a cohort of treated HIV-infected individuals with low measurable cardiovascular risk, we have observed evidence of premature subclinical atherosclerosis.

Normal Myocardial Flow Reserve in HIV-Infected Patients on Stable Antiretroviral Therapy: A Cross-Sectional Study Using Rubidium-82 PET/CT

Studies have found HIV-infected patients to be at increased risk of myocardial infarction, which may be caused by coronary microvascular dysfunction. For the first time among HIV-infected patients, we assessed the myocardial flow reserve (MFR) by Rubidium-82 (82Rb) positron emission tomography (PET), which can quantify the coronary microvascular function. MFR has proved highly predictive of future coronary artery disease and cardiovascular events in the general population.In a prospective cross-sectional study, HIV-infected patients all receiving antiretroviral therapy (ART) with full viral suppression and HIV-uninfected controls were scanned using 82Rb PET/computed tomography at rest and adenosine-induced stress, thereby obtaining the MFR (stress flow/rest flow), stratified into low ≤1.5, borderline >1.5 to 2.0, or normal >2.0.Fifty-six HIV-infected patients and 25 controls were included. The HIV-infected patients had a mean age of 53 years (range 37-68 years) with 23% active smokers. The controls had a mean age of 52 years (range 36-68 years) and 26% active smokers. In the HIV-infected group 73% had a normal MFR, 17% borderline, and 10% low values of MFR. Among controls these values were 71%, 19%, and 10%, respectively (P = 0.99). However, the HIV-infected group had lower values of stress myocardial blood flow (MBF) (2.63 ± 0.09 mL/g/min vs 2.99 ± 0.14 mL/g/min; P = 0.03). We found no evidence of decreased MFR as assessed by 82Rb PET among HIV-infected patients on stable ART with full viral suppression compared with HIV-uninfected controls. We did notice a decreased MBF during stress.

Vasculitis: an unusual manifestation in an HIV-infected patient

Human immunodeficiency virus (HIV) positive patients may develop vasculitis, either mediated by immunological factors or by direct vascular injury. We describe a patient who developed manifestations suggestive of extremities vasculitis with no identifiable risk factors other than HIV, Epstein Barr and Herpes Simplex Virus (HSV) type 1 co-infection. Physicians should be aware that vasculitis may have a heterogeneous presentation and occur associated with HIV infection. Although unusual, this association should be recognized for early proper treatment and prevention of ischemia.

Stimulating high impact HIV-related cardiovascular research: recommendations from a multidisciplinary NHLBI Working Group on HIV-related heart, lung, and blood disease

The clinical challenges confronting patients with human immunodeficiency virus (HIV) have shifted from acquired immunodeficiency syndrome (AIDS)-related illnesses to chronic diseases, such as coronary artery disease, chronic lung disease, and chronic anemia. With the growing burden of HIV-related heart, lung, and blood (HLB) disease, the National Heart, Lung, and Blood Institute (NHLBI) recognizes it must stimulate and support HIV-related HLB research. Because HIV offers a natural, accelerated model of common pathological processes, such as inflammation, HIV-related HLB research may yield important breakthroughs for all patients with HLB disease. This paper summarizes the cardiovascular recommendations of an NHLBI Working Group, Advancing HIV/AIDS Research in Heart, Lung, and Blood Diseases, charged with identifying scientific priorities in HIV-related HLB disease and developing recommendations to promote multidisciplinary collaboration among HIV and HLB investigators. The working group included multidisciplinary sessions, as well as HLB breakout sessions for discussion of disease-specific issues, with common themes about scientific priorities and strategies to stimulate HLB research emerging in all 3 groups.

Declining relative risk for myocardial infarction among HIV-positive compared with HIV-negative individuals with access to care

Concerns remain for an increased myocardial infarction (MI) risk among individuals infected with human immunodeficiency virus (HIV). We conducted a cohort study evaluating MI risk from 1996 to 2011 by HIV status. The adjusted MI rate ratio for HIV status declined over time, reaching 1.0 (95% confidence interval, .7-1.4) in 2010-2011, the most recent study period.

The role of T cells in the development of cardiovascular disease in HIV-infected patients

Cardiovascular disease (CVD) is highly prevalent in HIV-infected patients. Besides the classical cardiovascular risk factors, HIV related factors play a role, such as immune activation and treatment with highly active antiretroviral therapy (HAART). The resulting T cell activation is regarded as one of the driving forces behind this accelerated atherogenesis. Interventions, such as early treatment and anti-inflammatory therapy, decreasing T cell activation might lead to a lower incidence of CVD in future HIV infected patients. This review specifically explores the role of T cells in the development of atherosclerosis in HIV-infected patients.

HIV and noncommunicable cardiovascular and pulmonary diseases in low- and middle-income countries in the ART era: what we know and best directions for future research

With the advent of effective antiretroviral therapy (ART), HIV is becoming a chronic disease. HIV-seropositive (+) patients on ART can expect to live longer and, as a result, they are at risk of developing chronic noncommunicable diseases related to factors, such as aging, lifestyle, long-term HIV infection, and the potential adverse effects of ART. Although data are incomplete, evidence suggests that even in low- and middle-income countries (LMICs), chronic cardiovascular and pulmonary diseases are increasing in HIV-positive patients. This review summarizes evidence-linking HIV infection to the most commonly cited chronic cardiovascular and pulmonary conditions in LMICs: heart failure, hypertension, coronary artery disease/myocardial infarction, stroke, obstructive lung diseases, and pulmonary arterial hypertension. We describe the observed epidemiology of these conditions, factors affecting expression in LMICs, and key populations that may be at higher risk (ie, illicit drug users and children), and finally, we suggest that strategic areas of research and training intended to counter these conditions effectively. As access to ART in LMICs increases, long-term outcomes among HIV-positive persons will increasingly be determined by a range of associated chronic cardiovascular and pulmonary complications. Actions taken now to identify those conditions that contribute to long-term morbidity and mortality optimize early recognition and diagnosis and implement effective prevention strategies and/or disease interventions are likely to have the greatest impact on limiting cardiovascular and pulmonary disease comorbidity and improving population health among HIV-positive patients in LMICs.

Human immunodeficiency virus-1 (HIV-1)-mediated apoptosis: new therapeutic targets

HIV has posed a significant challenge due to the ability of the virus to both impair and evade the host’s immune system. One of the most important mechanisms it has employed to do so is the modulation of the host’s native apoptotic pathways and mechanisms. Viral proteins alter normal apoptotic signaling resulting in increased viral load and the formation of viral reservoirs which ultimately increase infectivity. Both the host’s pro- and anti-apoptotic responses are regulated by the interactions of viral proteins with cell surface receptors or apoptotic pathway components. This dynamic has led to the development of therapies aimed at altering the ability of the virus to modulate apoptotic pathways. These therapies are aimed at preventing or inhibiting viral infection, or treating viral associated pathologies. These drugs target both the viral proteins and the apoptotic pathways of the host. This review will examine the cell types targeted by HIV, the surface receptors exploited by the virus and the mechanisms whereby HIV encoded proteins influence the apoptotic pathways. The viral manipulation of the hosts’ cell type to evade the immune system, establish viral reservoirs and enhance viral proliferation will be reviewed. The pathologies associated with the ability of HIV to alter apoptotic signaling and the drugs and therapies currently under development that target the ability of apoptotic signaling within HIV infection will also be discussed.

Monocyte activation from interferon-α in HIV infection increases acetylated LDL uptake and ROS production

Atherosclerosis is an inflammatory disease that is accelerated in human immunodeficiency virus (HIV) infection. Individuals with HIV infection have an activated type I interferon (IFN) monocyte phenotype, which may enhance uptake of modified low-density lipoprotein (LDL) thereby initiating a prefoam cell pathology and recruitment into atherosclerotic plaques. In a sampling of HIV-infected subjects, an increase in monocyte activation genes, MX1 and CXCL10, correlated with monocyte expression of the scavenger receptor A (SR-A), a major receptor for lipid uptake and foam cell formation. Monocytes from HIV-infected subjects accumulated more lipid than control uninfected subjects. We modeled increased activation in HIV infection by priming human monocytes with IFNα followed by exposure to acetylated LDL (acLDL). Exposure to IFNα increased acLDL uptake, which generated increased cellular reactive oxygen species (ROS). We posit that HIV infection augments formation of arterial plaques by triggering monocyte activation with a type I IFN profile, which induces SR-A expression, lipid uptake, and subsequent ROS production. These findings may explain in part why HIV-infected individuals with chronic immune activation have an increased risk of atherosclerosis.

Immunodeficiency and risk of myocardial infarction among HIV-positive individuals with access to care

BACKGROUND

We sought to clarify the association of HIV infection and immunodeficiency on myocardial infarction (MI) risk.

METHODS

We conducted a cohort study from 1996 to 2009 of HIV-positive (HIV) and demographically matched HIV-negative (HIV) Kaiser Permanente California health plan members. Rate ratios (RRs) were obtained from Poisson regression models comparing MI incidence rates between HIV (overall and stratified by recent and nadir CD4 count, and recent HIV RNA levels) and HIV subjects, adjusting for age, sex, calendar era, race/ethnicity, census-based socioeconomic status, smoking, alcohol/drug abuse, overweight/obesity, diabetes, hypertension, and lipid-lowering therapy. Among HIV subjects, we also evaluated the independent association of CD4, HIV RNA, and antiretroviral therapy (ART) use.

RESULTS

The study population included 22,081 HIV and 230,069 HIV subjects. The crude MI incidence rate per 100,000 person-years was 283 and 165 for HIV and HIV subjects, respectively, with an adjusted RR of 1.4 [95% confidence interval (CI): 1.3 to 1.6]. Compared with HIV subjects (reference), MI rates were similar for HIV subjects with recent CD4 ≥500 cells per microliter (RR = 1.18; 95% CI: 0.96 to 1.45) and those with nadir CD4 ≥500 cells per microliter (RR = 0.85; 95% CI: 0.55 to 1.33). Among HIV subjects, nadir CD4 was the only HIV-specific factor associated with MIs (RR per 100 cells = 0.88; 95% CI: 0.81 to 0.96), whereas recent CD4 and HIV RNA, prior ART use, and duration of protease inhibitors and nonnucleoside reverse transcriptase inhibitors were not associated with MIs.

CONCLUSION

HIV subjects with recent or nadir CD4 ≥500 cells per microliter had similar MI rates compared with HIV subjects. Lower nadir CD4, in particular, seems to be independently associated with MIs. These results strengthen recommendations for earlier ART initiation.

HIV infection and cardiovascular disease

AIMS

With the success of antiretroviral therapy (ART), non-human immunodeficiency virus (HIV)-related comorbidities like cardiovascular diseases (CVDs) are of increasing concern. We describe important recent research developments on the epidemiology of CVD in HIV infection, ART-related metabolic changes, and cardioprotective anti-inflammatory mechanisms, and summarize management strategies for CVD risk reduction.

METHODS AND RESULTS

We systematically identified and analysed systematic reviews and most cited literature published in the last 3 years and supplemented findings with selected evidence based on clinical expertise. Among HIV-infected individuals, the prevalence of CVD risk factors and the risk for CVD is higher compared with HIV negatives. Antiretroviral drugs may induce dyslipidaemia, reduce insulin sensitivity, and promote body fat redistribution that additionally contributes to CVD risk. Some antiretroviral drugs may increase risk for CVD events, but the absolute risk increase is moderate and has to be put into perspective with the massive HIV-related benefits. Sustained HIV suppression reduces systemic inflammatory markers and is associated with a moderate reduction in CVD events. Regular CVD risk assessment and counselling to stop smoking must be regularly done in all HIV-infected individuals. Statins are effective for the treatment of dyslipidaemia in HIV infection, but drug interactions with ART need to be considered.

CONCLUSION

Human immunodeficiency virus-infected individuals are at increased risk for CVD. Timely initiation of ART with consequent viral suppression is likely to reduce CVD events and to offset potential side effects from ART-induced metabolic changes. Reduction in smoking in HIV-infected individuals is a public health priority.

HIV, inflammation, and calcium in atherosclerosis

Atherosclerosis is consistently higher among the HIV-positive patients, with or without treatment, than among the HIV-negative population. Risk factors linked to atherosclerotic cardiovascular disease in HIV infection are both traditional and HIV specific although the underlying mechanisms are not fully delineated. Three key sequential biological processes are postulated to accelerate progression of atherosclerosis in the context of HIV: (1) inflammation, (2) transformation of monocytes to macrophages and then foam cells, and (3) apoptosis of foam cells leading to plaque development through Ca(2+)-dependent endoplasmic reticulum stress. These proatherogenic mechanisms are further affected when HIV interacts with the genes involved in various phases within this network.

Cardiovascular disease and HIV infection

The emergence of chronic disease complications in controlled HIV disease has changed the landscape of HIV clinical care. HIV infection confers an increased cardiovascular disease risk, which is thought to be due to a complex interplay of mechanistic factors. While traditional cardiovascular risk factors likely play a role, recent evidence suggests that HIV-associated inflammation and immune activation are important mediators of cardiovascular risk. It is unclear whether established preventative interventions for the general population are applicable to HIV-infected patients, and the need to translate mechanistic knowledge into HIV-specific clinical interventions represents an important priority. Developing strategies to prevent cardiovascular disease in HIV-infected individuals calls for a multidisciplinary approach and represents an opportunity to exert a major public health impact in an at-risk population.

Retinal arterioles narrow with increasing duration of anti-retroviral therapy in HIV infection: a novel estimator of vascular risk in HIV?

OBJECTIVES

HIV infection is associated with an increased risk of age-related morbidity mediated by immune dysfunction, atherosclerosis and inflammation. Changes in retinal vessel calibre may reflect cumulative structural damage arising from these mechanisms. The relationship of retinal vessel calibre with clinical and demographic characteristics was investigated in a population of HIV-infected individuals in South Africa.

METHODS

Case-control study of 491 adults ≥30 years, composed of 242 HIV-infected adults and 249 age- and gender-matched HIV-negative controls. Retinal vessel calibre was measured using computer-assisted techniques to determine mean arteriolar and venular diameters of each eye.

RESULTS

The median age was 40 years (IQR: 35-48 years). Among HIV-infected adults, 87.1% were receiving highly active antiretroviral therapy (HAART) (median duration, 58 months), their median CD4 count was 468 cells/µL, and 84.3% had undetectable plasma viral load. Unadjusted mean retinal arteriolar diameters were 163.67±17.69 µm in cases and 161.34±17.38 µm in controls (p = 0.15). Unadjusted mean venular diameters were 267.77±18.21 µm in cases and 270.81±18.98 µm in controls (p = 0.07). Age modified the effect of retinal arteriolar and venular diameters in relation to HIV status, with a tendency towards narrower retinal diameters in HIV cases but not in controls. Among cases, retinal arteriolar diameters narrowed with increasing duration of HAART, independently of age (167.83 µm <3 years of HAART vs. 158.89 µm >6 years, p-trend = 0.02), and with a HIV viral load >10,000 copies/mL while on HAART (p = 0.05). HIV-related venular changes were not detected.

CONCLUSIONS

Narrowing of retinal arteriolar diameters is associated with HAART duration and viral load, and may reflect heightened inflammatory and pro-atherogenic states of the systemic vasculature. Measurement of retinal vascular calibre could be an innovative non-invasive method of estimating vascular risk in HIV-infected individuals.

HIV infection and stroke: current perspectives and future directions

HIV infection can result in stroke via several mechanisms, including opportunistic infection, vasculopathy, cardioembolism, and coagulopathy. However, the occurrence of stroke and HIV infection might often be coincidental. HIV-associated vasculopathy describes various cerebrovascular changes, including stenosis and aneurysm formation, vasculitis, and accelerated atherosclerosis, and might be caused directly or indirectly by HIV infection, although the mechanisms are controversial. HIV and associated infections contribute to chronic inflammation. Combination antiretroviral therapies (cART) are clearly beneficial, but can be atherogenic and could increase stroke risk. cART can prolong life, increasing the size of the ageing population at risk of stroke. Stroke management and prevention should include identification and treatment of the specific cause of stroke and stroke risk factors, and judicious adjustment of the cART regimen. Epidemiological, clinical, biological, and autopsy studies of risk, the pathogenesis of HIV-associated vasculopathy (particularly of arterial endothelial damage), the long-term effects of cART, and ideal stroke treatment in patients with HIV are needed, as are antiretrovirals that are without vascular risk.