Association between Immune Markers and Surrogate Markers of Cardiovascular Disease in HIV Positive Patients: A Systematic Review

Cardiovascular Risk Estimation Is Suboptimal in People With HIV

BACKGROUND

Established cardiovascular disease (CVD) risk prediction functions may not accurately predict CVD risk in people with HIV. We assessed the performance of 3 CVD risk prediction functions in 2 HIV cohorts.

METHODS AND RESULTS

CVD risk scores were calculated in the Mass General Brigham and Kaiser Permanente Northern California HIV cohorts, using the American College of Cardiology/American Heart Association atherosclerotic CVD function, the FHS (Framingham Heart Study) hard coronary heart disease function and the Framingham Heart Study hard CVD function. Outcomes were myocardial infarction or coronary death for FHS hard coronary heart disease function; and myocardial infarction, stroke, or coronary death for American College of Cardiology/American Heart Association and FHS hard CVD function. We calculated regression coefficients and assessed discrimination and calibration by sex; predicted to observed risk of outcome was also compared. In the combined cohort of 9412, 158 (1.7%) had a coronary heart disease event, and 309 (3.3%) had a CVD event. Among women, CVD risk was generally underestimated by all 3 risk functions. Among men, CVD risk was underestimated by the American College of Cardiology/American Heart Association and FHS hard CVD function, but overestimated by the FHS hard coronary heart disease function. Calibration was poor for women using the FHS hard CVD function and for men using all functions. Discrimination in all functions was good for women (c-statistics ranging from 0.78 to 0.90) and moderate for men (c-statistics ranging from 0.71 to 0.72).

CONCLUSIONS

Established CVD risk prediction functions generally underestimate risk in people with HIV. Differences in model performance by sex underscore the need for both HIV-specific and sex-specific functions. Development of CVD risk prediction models tailored to HIV will enhance care for aging people with HIV.

Risk Factors for Community and Intrahousehold Transmission of SARS-CoV-2: Modeling in a Nationwide French Population-Based Cohort Study, the EpiCoV Study

We assessed the risk of acquiring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from household and community exposure according to age, family ties, and socioeconomic and living conditions using serological data from a nationwide French population-based cohort study, the Epidémiologie et Conditions de Vie (EpiCoV) Study. A history of SARS-CoV-2 infection was defined by a positive anti-SARS-CoV-2 enzyme-linked immunosorbent assay immunoglobulin G result in November-December 2020. We applied stochastic chain binomial models fitted to the final distribution of household infections to data from 17,983 individuals aged ≥6 years from 8,165 households. Models estimated the competing risks of being infected from community and household exposure. The age group 18-24 years had the highest risk of extrahousehold infection (8.9%, 95% credible interval (CrI): 7.5, 10.4), whereas the oldest (≥75 years) and youngest (6-10 years) age groups had the lowest risk, at 2.6% (95% CrI: 1.8, 3.5) and 3.4% (95% CrI: 1.9, 5.2), respectively. Extrahousehold infection was also associated with socioeconomic conditions. Within households, the probability of person-to-person transmission increased with age, from 10.6% (95% CrI: 5.0, 17.9) among children aged 6-10 years to 43.1% (95% CrI: 32.6, 53.2) among adults aged 65-74 years. Transmission was higher between partners (29.9%, 95% CrI: 25.6, 34.3) and from mother to child (29.1%, 95% CrI: 21.4, 37.3) than between individuals related by other family ties. In 2020 in France, the main factors identified for extrahousehold SARS-CoV-2 infection were age and socioeconomic conditions. Intrahousehold infection mainly depended on age and family ties.

Sex modifies the association between HIV and coronary artery disease among older adults in Uganda

INTRODUCTION

Little is known about the epidemiology of coronary artery disease (CAD) in sub-Saharan Africa, where the majority of people living with HIV (PLHIV) live. We assessed the association of HIV with CAD and explored relationships with monocyte activation in sex-stratified analyses of older PLHIV and people without HIV (PWOH) in Uganda.

METHODS

The Ugandan Study of HIV effects on the Myocardium and Atherosclerosis (mUTIMA) follows 100 PLHIV on antiretroviral therapy (ART) and 100 age- and sex-matched PWOH controls in Kampala, Uganda; all >45 years of age with >1 cardiovascular disease risk factor. At the year 2 exam (2017-2019), 189 participants had available coronary calcium score and 165 had coronary CT angiography (CCTA) for this analysis. A subset of participants (n = 107) had both CCTA and fresh whole blood flow cytometry for monocyte phenotyping.

RESULTS

Median age was 57.8 years and 63% were females. Overall, 88% had hypertension, 37% had diabetes and 4% were smokers. Atherosclerotic cardiovascular disease (ASCVD) risk was modestly higher for PWOH, but not statistically significant (median 10-year ASCVD risk 7.2% for PLHIV vs. 8.6% for PWOH, p = 0.09). Median duration of ART was 12.7 years and 86% had suppressed viral load. Despite a high prevalence of risk factors, only 34/165 (21%, 95% CI 15-28%) had any coronary plaque. After adjustment for ASCVD risk score, HIV status was not associated with CAD (OR 0.55, 95% CI 0.23-1.30) but was associated with more severe CAD (segment severity score>3) among those with disease (OR 10.9, 95% CI 1.67-70.45). Females had a trend towards higher odds of CAD among PLHIV (OR 4.1, 95% CI 0.4-44.9), but a trend towards lower odds of CAD among PWOH (OR 0.30; 95% CI 0.07-1.3; HIV*sex interaction p = 0.019). CAD was positively correlated with classical monocytes (r = 0.3, p = 0.012) and negatively correlated with CX3CR1 expression (r = -0.31, p = 0.011) in PLHIV and negatively correlated with patrolling monocytes (r = -0.36, p = 0.031) and tissue factor expression (r = -0.39, p = 0.017) in PWOH.

CONCLUSIONS

Our results suggest that HIV may be associated more with severity rather than the presence of CAD in Uganda. Sex differences in the HIV effect suggest that tailored CAD prevention strategies may be required in this setting.

Advanced Glycation End Products Associated With Cardiometabolic Biomarkers in Treated Human Immunodeficiency Virus Infection

Background

Despite advances in antiretroviral therapy (ART), people living with human immunodeficiency virus (HIV) continue to be at increased risk of cardiometabolic complications compared to HIV-uninfected individuals. Advanced glycation end products (AGEs) are implicated in the development and progression of cardiometabolic complications in the general population. Their role in HIV remains unclear.

Methods

ACTG A5260s is a prospective open-label randomized trial in which ART-naive people living with HIV were randomized to tenofovir disoproxil fumarate /emtricitabine plus atazanavir/ritonavir, darunavir/ritonavir, or raltegravir over 96 weeks. Changes in circulating AGEs with ART initiation were assessed, and linear regression was used to examine the associations between serum AGEs with carotid intima-media thickness (cIMT), visceral and subcutaneous adipose tissue, total fat, lean mass, body mass index, insulin resistance, leptin, and adiponectin.

Results

Overall, 214 participants were included. Ninety percent were male, 48% were White, the median age was 36 years, median HIV-1 RNA was 4.58 log₁₀ copies/mL, and median CD4 count was 338 cells/µL. Most AGEs remained relatively unchanged following 96 weeks of ART initiation, except for methylglyoxal-derived hydroimidazolone 1 (MG-H1), which increased following 96 weeks of ART (mean fold change, 1.15 [95% confidence interval, 1.02–1.30]). No differences were detected across ART regimens. Increases in AGE levels over time were associated with worsening body fat composition measures, insulin resistance, and cIMT, even after adjusting for clinically relevant factors.

Conclusions

AGE levels did not decrease following ART initiation. Most AGE levels remained stable, except for MG-H1, which increased. In people with HIV on ART, the accumulation of circulating AGEs over time appears to be independently associated with worsening cardiometabolic biomarkers.

Summary: Antiretroviral therapy (ART) does not appear to be effective in reducing advanced glycation end product (AGE) levels. On the contrary, AGE levels seem to increase following ART initiation. Accumulation of AGEs was found to be independently associated with cardiometabolic complications in treated people living with HIV.

Central obesity is a contributor to systemic inflammation and monocyte activation in virally suppressed adults with chronic HIV in Kenya

OBJECTIVES

Heightened systemic inflammation is common in obese individuals and persons with HIV (PWH) and is independently associated with an increased risk of cardiovascular diseases (CVDs). We investigated the combined effect of central obesity, a surrogate measure of visceral fat and HIV on circulating levels of inflammatory cytokines among Kenyan adults.

DESIGN

A cross-sectional study.

METHODS

We analysed and compared data from 287 virally suppressed PWH and 277 noninfected Kenyan adults, including biomarkers of gut epithelial dysfunction (intestinal fatty acid binding protein), monocyte activation (soluble CD163 and CD14) and inflammation [interleukin (IL)-1β, IL-6, TNF-α and hsCRP] by HIV/central obesity status (HIV-positive/obese, HIV-negative/obese, HIV-positive/nonobese and HIV-negative/nonobese). Central obesity was defined as waist circumference more than 80 cm for women and more than 94 cm for men. We assessed the association of HIV/obesity status with elevated biomarkers (>75th percentile) using logistic regression.

RESULTS

Median age for participants was 44 years and 37% were centrally obese. Levels of all biomarkers were higher among the HIV-positive/obese compared with the HIV-negative/nonobese (P < 0.05 for all comparisons). The HIV-positive/obese group had the greatest odds of having elevated inflammatory biomarkers compared with other groups even after adjustment of age, BMI and other conventional CVD risk factors (P < 0.05 for all). Additional adjustment for sCD163 in the multivariate model substantially attenuated the association for HIV-positive/obesity with IL-1β, IL-6 and TNF-α but not hsCRP. The contribution of HIV-positive/obesity to inflammation was independent of the degree of immunosuppression.

CONCLUSION

Central obesity is prevalent among virally suppressed African PWH and is associated with greater inflammation and monocyte activation independent of other comorbidities and HIV-specific factors.

Patterns of Immune Activation in HIV and Non HIV Subjects and Its Relation to Cardiovascular Disease Risk

Introduction

Insight into inflammation patterns is needed to understand the pathophysiology of HIV and related cardiovascular disease (CVD). We assessed patterns of inflammation related to HIV infection and CVD risk assessed with carotid intima media thickness (CIMT).

Methods

A cross-sectional study was performed in Johannesburg, South Africa, including participants with HIV who were virally suppressed on anti-retroviral therapy (ART) as well as HIV-negative participants who were family members or friends to the HIV-positive participants. Information was collected on CVD risk factors and CIMT. Inflammation was measured with the Olink panel ‘inflammation’, allowing to simultaneously assess 92 inflammation markers. Differences in inflammation patterns between HIV-positive and HIV-negative participants were explored using a principal component analysis (PCA) and ANCOVA. The impact of differentiating immune markers, as identified by ANCOVA, on CIMT was assessed using linear regression while adjusting for classic CVD risk factors.

Results

In total, 185 HIV-positive and 104 HIV negative participants, 63% females, median age 40.7 years (IQR 35.4 – 47.7) were included. HIV-positive individuals were older (+6 years, p <0.01) and had a higher CIMT (p <0.01). No clear patterns of inflammation were identified by use of PCA. Following ANCOVA, nine immune markers differed significantly between HIV-positive and HIV-negative participants, including PDL1. PDL1 was independently associated with CIMT, but upon stratification this effect remained for HIV-negative individuals only.

Conclusion

HIV positive patients on stable ART and HIV negative controls had similar immune activation patterns. CVD risk in HIV-positive participants was mediated by inflammation markers included in this study.

Prevalence of Silent Atherosclerosis and Other Comorbidities in an Outpatient Cohort of Adults Living with HIV: Associations with HIV Parameters and Biomarkers

People living with HIV (PLWH) are at risk of noninfectious comorbidities. It is important to individualize those at higher risk. In a single-center cohort of PLWH, we performed a cross-sectional analysis of comorbidities, diagnosed according to standard procedures. The primary endpoint was the prevalence of subclinical carotid/coronary atherosclerosis. Secondary endpoints were its association with selected inflammatory/immune activation biomarkers and with other comorbidities. Associations were examined by using Chi-square or Fisher's exact test for categorical variables and Student or Wilcoxon tests for quantitative variables, and a stepwise multivariate logistical model was performed for further exploration. Among 790 participants [median age: 49.8 years (interquartile range, IQR: 44.5-55.6), 77.1% males, median CD4: 536/mm³ (IQR: 390-754), 83.6% with undetectable viral load], asymptomatic atherosclerosis was found in 26% and was associated in multivariate analysis with older age, longer known duration of infection, higher sCD14, and lower adiponectin levels. Hypertension was found in 33.5% of participants, diabetes in 19.4%, renal impairment in 14.6%, elevated low-density lipoprotein-cholesterol in 13.3%, elevated triglyceride/high-density lipoprotein (HDL)-cholesterol ratio in 6.6%, and osteoporosis in 7.9%. The presence of two or more comorbidities was found in 42.1% of participants and was associated in multivariate analysis with older age and longer exposure to antiretrovirals. Comorbidities were diversely associated with biomarkers: osteoporosis with higher IL-6, renal impairment with higher sCD14, hypertension with higher D-dimer, diabetes and elevated triglyceride/HDL-cholesterol ratio both with lower adiponectin and lower 25-hydroxyvitamin D. Asymptomatic atherosclerosis and multimorbidity were frequent in a cohort of middle-aged, well-controlled, PLWH and were associated with traditional and HIV-specific factors. Associations between morbidities and inflammatory/immune activation biomarkers were diverse.

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.

Antiretroviral therapy reduces but does not normalize immune and vascular inflammatory markers in adults with chronic HIV infection in Kenya

INTRODUCTION

Markers of monocyte/macrophage activation and vascular inflammation are associated with HIV-related cardiovascular diseases (CVD) and mortality. We compared these markers among African people living with HIV (PLWH) and HIV-negative adults, and examined risk factors associated with elevated biomarkers (>75th percentile) in PLWH on antiretroviral therapy (ART).

DESIGN

Cross-sectional study.

METHODS

We measured serum concentrations of a gut integrity biomarker (intestinal-fatty acid binding protein), monocyte/macrophage activation biomarkers (soluble CD14 and CD163), and vascular inflammation biomarkers [soluble intercellular adhesion molecule 1 (sICAM-1) and soluble vascular adhesion molecule 1 (sVCAM-1)]. We assessed the relationship of these inflammatory parameters with HIV, using logistic regression adjusting for traditional CVD risk factors.

RESULTS

Among the 541 participants, median age was 43 years and half were female. Among 275 PLWH, median CD4 T-cell count and duration of ART use was 509 cells/μl and 8 years, respectively. PLWH had significantly higher prevalence of elevated inflammatory biomarkers compared with HIV-negative individuals even after adjustment for traditional CVD risk factors. Compared with individuals without HIV, the prevalence of elevated biomarkers was highest among persons with detectable viral load and CD4 T-cell counts 200 cells/μl or less. In a subanalysis among PLWH, nadir CD4 T-cell count 200 cells/μl or less was associated with elevated soluble CD14 (sCD14); dyslipidemia with elevated sCD14, sICAM-1, and sVCAM-1; and overweight/obesity with reduced sCD14. Longer ART exposure (>4 years) was associated with reduced sVCAM-1 and sICAM-1.

CONCLUSION

HIV and not traditional CVD risk factors is a primary contributor of monocyte/macrophage activation and inflammation despite ART. Anti-inflammatory therapies in addition to ART may be necessary to reduce these immune dysregulations and improve health outcomes of African PLWH.

Statin effect on coronary calcium distribution, mass and volume scores and associations with immune activation among HIV+ persons on antiretroviral therapy

BACKGROUND

Inflammation has been associated with whole heart coronary artery calcification (CAC) among people with HIV (PWH) on antiretroviral therapy (ART); however, prior studies have not evaluated the distribution of calcium or separated mass versus volume scores, which are differentially associated with clinical events in the general population. Statins may also have a greater effect on CAC mass compared with volume.

METHODS

147 PWH were randomized 1:1 to rosuvastatin 10 mg or placebo and followed for 96 weeks. We re-analysed coronary calcium scans from 0, 48 and 96 weeks to determine mass and volume scores and measures of CAC diffusivity. Mixed effects models and generalized estimating equations were used to examine longitudinal associations of CAC with treatment and biomarkers.

RESULTS

Median age at study entry was 46 years; 78% were male and 68% African American. Median CD4+ was 613 and half were on protease inhibitors. Randomization to statin therapy was not associated with a change in mass score, volume score, number of involved vessels or diffusivity index (all P>0.1). Soluble CD14 was associated with the presence of CAC (P=0.05) and borderline associated with number of involved vessels (P=0.07) across all three time points.

CONCLUSIONS

In PWH on ART, moderate intensity rosuvastatin does not appear to have a significant effect on volume, mass or regional distribution of CAC over 96 weeks. We extend previous cross-sectional observations to show that soluble CD14 is associated with whole heart CAC over time and independently of age and systolic blood pressure.

Integrating HIV pre-exposure prophylaxis and harm reduction among men who have sex with men and transgender women to address intersecting harms associated with stimulant use: a modelling study

INTRODUCTION

Among men who have sex with men (MSM) and transgender women (TW), stimulant use is high and has been associated with an increased risk of HIV infection, suicide and cardiovascular disease (CVD) mortality. We used epidemic modelling to investigate these intersecting health harms among MSM/TW in Lima, Peru and assess whether they could be mitigated by prioritizing HIV pre-exposure prophylaxis (PrEP) and harm reduction interventions among MSM/TW who use stimulants.

METHODS

We adapted a dynamic model of HIV transmission among MSM/TW in Lima to incorporate stimulant use and increased HIV risk, suicide and CVD mortality. Among 6% to 24% of MSM/TW using stimulants (mostly cocaine), we modelled an increased risk of unprotected anal sex (RR = 1.35 [95%CI: 1.17 to 1.57]) obtained from local data, and increased risk of suicide (SMR = 6.26 [95%CI: 2.84 to 13.80]) and CVD (SMR = 1.83 [95%CI: 0.39 to 8.57]) mortality associated with cocaine use based on a global systematic review. We estimated the proportion of health harms occurring among MSM/TW who use stimulants in the next year (01-2020/01-2021). We also investigated the 10-year impact (01-2020/01-2030) of: (1) PrEP prioritization for stimulant-using MSM/TW compared to random allocation, and (2) integrating PrEP with a theoretical intervention halving stimulant-associated risk.

RESULTS

MSM/TW in Lima will experience high HIV incidence, suicide mortality and CVD mortality (1.6/100 py, and 0.018/100 py, 0.13/100 py respectively) in 2020. Despite stimulant using MSM/TW comprising an estimated 9.5% (95%CI: 7.8 to 11.5) of all MSM/TW, in the next year, 11% 95%CI (i.e. 2.5% to 97.5% percentile) 10% to 13%) of new HIV infections, 39% (95%CI: 18% to 60%) of suicides and 15% (95%CI: 3% to 44%) of CVD deaths could occur among this group. Scaling up PrEP among all stimulant using MSM/TW could prevent 19% (95%CI: 11% to 31%) more HIV infections over 10 years compared to random allocation. Integrating PrEP and an intervention to halve stimulant-associated risks could reduce new HIV infections by 20% (95%CI: 10% to 37%), suicide deaths by 14% (95%CI: 5% to 27%) and CVD deaths by 3% (95%CI: 0% to 16%) over a decade.

CONCLUSIONS

MSM/TW who use stimulants experience a disproportionate burden of health harms. Prioritizing PrEP based on stimulant use, in addition to sexual behaviour/gender identity criteria, could increase its impact. Integrated substance use, harm reduction, mental health and HIV care among MSM/TW is needed.

Network analysis of host-pathogen protein interactions in microbe induced cardiovascular diseases

Large-scale visualization and analysis of HPIs involved in microbial CVDs can provide crucial insights into the mechanisms of pathogenicity. The comparison of CVD associated HPIs with the entire set of HPIs can identify the pathways specific to CVDs. Therefore, topological properties of HPI networks in CVDs and all pathogens was studied using Cytoscape3.5.1. Ontology and pathway analysis were done using KOBAS 3.0. HPIs of Papilloma, Herpes, Influenza A virus as well as Yersinia pestis and Bacillus anthracis among bacteria were predominant in the whole (wHPI) and the CVD specific (cHPI) network. The central viral and secretory bacterial proteins were predicted virulent. The central viral proteins had higher number of interactions with host proteins in comparison with bacteria. Major fraction of central and essential host proteins interacts with central viral proteins. Alpha-synuclein, Ubiquitin ribosomal proteins, TATA-box-binding protein, and Polyubiquitin-C &B proteins were the top interacting proteins specific to CVDs. Signaling by NGF, Fc epsilon receptor, EGFR and ubiquitin mediated proteolysis were among the top enriched CVD specific pathways. DEXDc and HELICc were enriched host mimicry domains that may help in hijacking of cellular machinery by pathogens. This study provides a system level understanding of cardiac damage in microbe induced CVDs.

WS. Characteristics, Prevention, and Management of Cardiovascular Disease in People Living With HIV: A Scientific Statement From the American Heart Association

As early and effective antiretroviral therapy has become more widespread, HIV has transitioned from a progressive, fatal disease to a chronic, manageable disease marked by elevated risk of chronic comorbid diseases, including cardiovascular diseases (CVDs). Rates of myocardial infarction, heart failure, stroke, and other CVD manifestations, including pulmonary hypertension and sudden cardiac death, are significantly higher for people living with HIV than for uninfected control subjects, even in the setting of HIV viral suppression with effective antiretroviral therapy. These elevated risks generally persist after demographic and clinical risk factors are accounted for and may be partly attributed to chronic inflammation and immune dysregulation. Data on long-term CVD outcomes in HIV are limited by the relatively recent epidemiological transition of HIV to a chronic disease. Therefore, our understanding of CVD pathogenesis, prevention, and treatment in HIV relies on large observational studies, randomized controlled trials of HIV therapies that are underpowered to detect CVD end points, and small interventional studies examining surrogate CVD end points. The purpose of this document is to provide a thorough review of the existing evidence on HIV-associated CVD, in particular atherosclerotic CVD (including myocardial infarction and stroke) and heart failure, as well as pragmatic recommendations on how to approach CVD prevention and treatment in HIV in the absence of large-scale randomized controlled trial data. This statement is intended for clinicians caring for people with HIV, individuals living with HIV, and clinical and translational researchers interested in HIV-associated CVD.

Rationale and design of the Mechanistic Substudy of the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE): Effects of pitavastatin on coronary artery disease and inflammatory biomarkers

BACKGROUND

People with HIV (PWH) have increased cardiovascular events, inflammation, and high-risk coronary atherosclerosis. Statin therapy has been shown to lower the risk of cardiovascular disease (CVD) in the general population, but whether this results from reductions in coronary atherosclerosis and is mediated by decreased inflammation remains unknown.

METHODS

REPRIEVE is a randomized, placebo-controlled trial of pitavastatin calcium (4 mg/day) vs. placebo enrolling at least 7500 PWH between 40-75 years, on antiretroviral therapy (ART), with low to moderate traditional CVD risk. The Mechanistic Substudy of REPRIEVE (A5333s) is co-enrolling 800 participants from 31 US sites. These participants undergo serial contrast enhanced coronary computed tomography angiography (CCTA) and measurements of biomarkers of inflammation and immune activation at baseline and after 2 years of follow-up. The primary objectives are to determine the effects of pitavastatin on noncalcified coronary atherosclerotic plaque (NCP) volume, low attenuation plaque, and positive remodeling and on changes in immune activation and inflammation and to assess relationships between the two. Changes in CAD will be assessed in a standardized fashion by a core lab with expert readers blinded to time points and participant information; immune activation and inflammation assessment is also performed centrally.

RESULTS

To date the Mechanistic Substudy has completed planned enrollment, with 805 participants.

CONCLUSION

This study represents the first large, randomized, CCTA-based assessment of the effects of a primary prevention strategy for CVD on high-risk CAD, immune activation and inflammation among PWH. The study will assess pitavastatin's effects on coronary plaque, and the interrelationship of these changes with biomarkers of immune activation and inflammation in PWH to determine mechanisms of CVD prevention and improved outcomes in this population.

HIV and Cardiovascular Disease: Update on Clinical Events, Special Populations, and Novel Biomarkers

PURPOSE OF REVIEW

The objective of this review is to provide an update on the link between HIV infection and cardiovascular disease (CVD). We will focus our review mainly on literature describing clinical CVD events and understudied topics of importance.

RECENT FINDINGS

Heart failure, peripheral artery disease, and stroke are CVD modalities deserving more attention in the context of HIV infection in the highly active antiretroviral therapy era. Incidence data on clinical CVD from HIV populations in low- and middle-income countries are limited. Multisubstance use is common in HIV, but understudied as a moderator or mediator of the association between HIV and CVD. CVD risk assessment in HIV remains challenging, but new research into novel biomarkers may provide further insights. There is also a need for inclusion of non-biologic factors in our attempts to understand, quantify, and predict CVD risk among PLWHA. Significant attention has been paid to generating and testing hypotheses to understand the mechanisms of myocardial infarction in HIV. Similar attention is deserving for heart failure, PAD, stroke, and cardiovascular disease risk in resource-limited settings and among substance users with HIV.

Coronary artery calcium, HIV and inflammation in Uganda compared with the USA

Objectives

To compare the prevalence of detectable coronary artery calcium (CAC) among higher risk, older people living with HIV (PLWH) and uninfected persons in Uganda versus the USA, and second to explore associations of CAC with HIV-specific variables and biomarkers of inflammation.

Methods

This cross-sectional study of 430 total subjects compared 100 PLWH on antiretroviral therapy and 100 age-matched and sex-matched HIV-uninfected controls in Uganda with 167 PLWH on antiretroviral therapy and 63 uninfected controls in the USA. Multivariable logistic regression was used to examine associations with detectable CAC (CAC >0).

Results

Compared with US subjects, Ugandans were older (mean age 56 vs 52 years) and were more likely to have diabetes (36% vs 3%) and hypertension (85% vs 36%), but were less likely to be male (38% vs 74%) or smokers (4% vs 56%). After adjustment for HIV serostatus, age, sex and traditional risk factors, Ugandans had substantially lower odds of CAC >0 (adjusted OR 0.07 (95% CI 0.03 to 0.17), p<0.001). HIV was not associated with CAC >0 in either country (p>0.1). Among all PLWH, nadir CD4 count was associated with the presence of CAC, and among Ugandans soluble intercellular adhesion molecule (p=0.044), soluble CD163 (p=0.004) and oxidised low-density lipoprotein (p=0.043) were all associated with the presence of CAC.

Conclusions

Ugandans had a dramatically lower prevalence of any coronary calcification compared with US subjects. The role of HIV infection and inflammation as risk factors for subclinical coronary disease in sub-Saharan Africa merits further investigation.

Inflammatory biomarkers and subclinical carotid atherosclerosis in HIV-infected and HIV-uninfected men in the Multicenter AIDS Cohort Study

BACKGROUND

HIV-infected persons have an increased risk of atherosclerosis relative to uninfected individuals. Inflammatory processes may contribute to this risk. We evaluated the associations of 10 biomarkers of systemic inflammation (CRP, IL-6, sTNF-αR1 and 2), monocyte activation (CCL2, sCD163, sCD14), coagulation (fibrinogen, D-dimer), and endothelial dysfunction (ICAM-1) with subclinical carotid atherosclerosis among participants in the Multicenter AIDS Cohort Study (MACS).

METHODS

Carotid plaque and intima media thickness (IMT) in the common carotid (CCA-IMT) and bifurcation region were assessed by B mode ultrasound among 452 HIV-infected and 276 HIV-uninfected men from 2010-2013. Associations between levels of each biomarker and presence of focal plaque and IMT were assessed by logistic and linear regression models, adjusting for demographics, risk behaviors, traditional cardiovascular disease (CVD) risk factors, and HIV disease characteristics.

RESULTS

Compared to HIV-uninfected men, HIV-infected men had significantly higher levels of 8 of the 10 biomarkers. Overall, men with sCD163, CCL2, IL-6, and CRP levels in the highest quintile had approximately 2 times the odds of carotid plaque relative to those with levels in the lowest quintile, independent of demographic and CVD risk factors. Fibrinogen levels were positively associated with CCA-IMT while ICAM-1, CCL2, and sTNF-αR1 levels were positively associated with bifurcation-IMT. Among HIV-uninfected men, higher levels of sTNF-αR2 were positively associated with CCA-IMT, fibrinogen with bifurcation-IMT and carotid plaque, and ICAM-1 with carotid plaque.

CONCLUSION

In addition to greater levels of systemic inflammation, heightened monocyte activation (sCD163, CCL2) may contribute to the burden of atherosclerosis among HIV-infected persons.

Current assessment of heart rate variability and QTc interval length in HIV/AIDS

PURPOSE OF REVIEW

The increasing prevalence of cardiovascular disease comorbidity in persons infected with the HIV has become a global concern. The electrocardiogram (ECG) is increasingly being utilized to provide clinically relevant information regarding cardiac arrhythmias and cardio-autonomic dysfunction. The purpose of this review is to summarize the latest research comparing QT and R-to-R interval length as a function of HIV+ status or antiretroviral therapy (ART) regimen.

RECENT FINDINGS

Prolongation of the corrected QTc interval may be acquired in HIV+ ART-naive individuals, exacerbated by various classes of ART drugs, and is generally predictive of lethal cardiac arrhythmias, with effects observed from childhood to adulthood. Recent literature also suggests the trend of lower heart rate variability in HIV is indicative of cardiorespiratory and inflammatory-immune dysfunction.

SUMMARY

These emergent studies support the clinical relevance of the ECG across the age and HIV disease spectrum. Furthermore, the reported findings have implications for the management of cardiovascular and chronic inflammatory disease comorbidity in persons living with HIV.

Platelet Transcriptome Profiling in HIV and ATP-Binding Cassette Subfamily C Member 4 (ABCC4) as a Mediator of Platelet Activity

An unbiased platelet transcriptome profile identified ATP binding cassette subfamily C member 4 (ABCC4) as a novel mediator of platelet activity in virologically suppressed human immunodeficiency virus (HIV)-infected subjects on antiretroviral therapy. Using ex vivo and in vitro cellular and molecular assays we demonstrated that ABCC4 regulated platelet activation by altering granule release and cyclic nucleotide homeostasis through a cAMP-protein kinase A (PKA)-mediated mechanism. Platelet ABCC4 inhibition attenuated platelet activation and effector cell function by reducing the release of inflammatory mediators, such as sphingosine-1-phosphate. ABCC4 inhibition may represent a novel antithrombotic strategy in HIV-infected subjects on antiretroviral therapy.

The effects of HIV and smoking on aortic and splenic inflammation

OBJECTIVE

To determine the association of smoking and HIV status with tissue-specific inflammation measured by flurodeoxyglucose positron emission tomography (PET).

DESIGN

A cross-sectional study.

METHODS

We prospectively enrolled 55 HIV study participants on stable antiretroviral therapy and 19 age-matched HIV-uninfected controls without known cardiovascular disease. We measured aortic target-to-background ratio (TBR) and spleen standardized uptake values (SUV) 3-h post-FDG, and used regression models to examine the independent association of HIV and smoking status with PET variables.

RESULTS

Overall, median (interquartile range) age was 50 (42-55) years; 81% were men and 54% were current smokers (median 0.5 packs/day, 25 pack-years]. Median CD4 of HIV study participants was 690 cells/ml and 88% had HIV-1 RNA less than 20 c/ml; 43% were on a protease inhibitor. In fully adjusted models, HIV was associated with 0.16 (95% confidence interval 0.04-0.27; P = 0.009) higher aortic TBR, whereas current smoking was marginally associated with a lower TBR [-0.11 (95% confidence interval -0.23 to 0.01); P = 0.07]. Spleen SUVmean was not associated with HIV or smoking, and there was no evidence for an HIVsmoking interaction for aortic or spleen models (all P > 0.1). Spleen SUVmean was positively associated with biomarkers of inflammation and coronary artery calcium, but adjustment for traditional cardiovascular disease risk factors attenuated these relationships.

CONCLUSION

The FDG-PET study of HIV study participants suggests that HIV is associated with increased aortic inflammation independent of traditional risk factors, but smoking is not. Future studies should continue to explore the mechanistic roles of smoking and inflammation at various stages of clinical and subclinical atherosclerotic vascular disease in HIV.