HIV-associated vascular diseases: Structural and functional changes, clinical implications

MOYAMOYA disease in an adolescent with HIV-1

Moyamoya disease has been reported in both children and adults with HIV-1. Most cases reported in children were found to have unsuppressed viral loads and low CD4 counts. Although the aetiology of the disease is largely unknown, a few studies have postulated cytokine imbalance and immune activation as possible causes. Intimal staining of the involved cerebral arteries have revealed transmembrane glycoprotein of HIV-gp 41. We present the case of an 18-year-old boy with congenitally acquired HIV-1 who presented with right hemiparesis at the age of 12 years and was found to have Moyamoya disease on neuroimaging. His CD4 count has always been low (<100 cells/cumm) in spite of being virally suppressed. He was started on anti-retroviral therapy at 5 and half years of age and he was continued on the same. He was treated conservatively and he continues to have residual right hemiparesis.

Endovascular management of HIV vasculopathy

HIV is a multisystem disease process that can affect the cardiovascular system resulting in vasculopathy. As highly active anti-retroviral therapy has allowed patients to live longer with the disease, vascular complications such as aneurysms, occlusive disease, spontaneous arteriovenous fistulae, and arterial dissections have been described. The pathogenesis of vascular-related complications in HIV is poorly understood but is thought to involve an interplay between viral-induced inflammation, vascular smooth muscle changes, endothelial alterations, and circulating blood factors. The most well-described management strategies for symptomatic aneurysm-related complications are surgical in nature, with mostly anecdotal reports of endovascular intervention. We present a case of a 24-year-old male who was found to have findings consistent with HIV vasculopathy on angiography after presenting with acute GI hemorrhage secondary to left gastric artery bleeding. Our patient was managed with endovascular embolization. Although studies have shown promise regarding the endovascular management of HIV-related aneurysmal complications in the short term, more research is needed to evaluate the long-term success of these interventions.

Neuropilin-1, a myeloid cell-specific protein, is an inhibitor of HIV-1 infectivity

Myeloid lineage cells such as macrophages and dendritic cells (DCs), targeted by HIV-1, are important vehicles for virus dissemination through the body as well as viral reservoirs. Compared to activated lymphocytes, myeloid cells are collectively more resistant to HIV-1 infection. Here we report that NRP-1, encoding transmembrane protein neuropilin-1, is highly expressed in macrophages and DCs but not CD4⁺ T cells, serving as an anti-HIV factor to inhibit the infectivity of HIV-1 progeny virions. Silencing NRP-1 enhanced the transmission of HIV-1 in macrophages and DCs significantly and increased the infectivity of the virions produced by these cells. We further demonstrated that NRP-1 was packaged into the progeny virions to inhibit their ability to attach to target cells, thus reducing the infectivity of the virions. These data indicate that NRP-1 is a newly identified antiviral protein highly produced in both macrophages and DCs that inhibit HIV-1 infectivity; thus, NRP-1 may be a novel therapeutic strategy for the treatment of HIV-1 infection.

Prevention of sudden cardiac death in persons living with HIV infection

Persons living with HIV infection (PLWH) have been recognized to have an increased risk of sudden cardiac death (SCD). Prevention of this risk should theoretically be included in their long-term management. However, only a few approaches have been proposed to optimize such interventions. Targeting detection of the commonly associated conditions such as coronary artery disease, left ventricular dysfunction, heart failure, QT interval prolongation and ventricular arrhythmias is the first step of this prevention. However, although detection of the risk of SCD is a suitable challenge in PLWH, it remains uncertain whether optimized treatment of the identified risks would unequivocally translate into a decrease in SCD rates.

Assessment of retinal microvascular health by optical coherence tomography angiography among persons with HIV

Microvasculopathy may link HIV-related chronic inflammation and premature multimorbidity. In this proof-of-concept study, we used optical coherence tomography angiography (OCTA) to evaluate the retina as a convenient assessment of microvascular health among persons with HIV (PWH) undergoing surveillance ophthalmic care at Emory from 2018 to 2021. Among patients with longstanding HIV, OCTA identified microvascular abnormalities even among eyes without clinical retinal disease. Retinovascular evaluation by OCTA is a feasible, noninvasive technique for assessing microvasculopathy among PWH.

Review of the neurological aspects of HIV infection

There are almost 40 million people in the world who live with the human immunodeficiency virus (HIV). The neurological manifestations associated with HIV contribute to significant morbidity and mortality despite the advances made with anti-retroviral therapy (ART). This review presents an approach to classification of neurological disorders in HIV, differentiating diseases due to the virus itself and those due to opportunistic infection. The effects of antiretroviral therapy are also discussed. The emphasis is on the developing world where advanced complications of HIV itself and infections such as tuberculosis (TB), toxoplasmosis and cryptococcal meningitis remain prevalent.

Sudden cardiac death in HIV-infected patients: A contemporary review

HIV‐infected individuals have an increased risk of sudden cardiac death compared to the general population; yet the mechanisms underlying this increased risk remain unclear. The mechanisms underlying the heightened sudden cardiac death risk in HIV‐infected individuals is likely multifactorial. We reviewed the literature to elucidate and summarize the potential mechanisms contributing to sudden cardiac death in the HIV patient population. There is biologic plausibility that the following mechanisms may be contributing to the significantly heightened risk of sudden cardiac death in HIV to varying degrees: ventricular arrhythmias, myocardial fibrosis and scar, prolonged QTc interval (both as a direct effect of HIV on repolarization as well as a result of concurrent medications/antiretroviral therapies), substance abuse, structural heart disease, and premature atherosclerosis. Further understanding of the mechanisms underlying the increased sudden cardiac death risk in HIV can lead to identification of modifiable risk factors, implementation of public health programs, and potential revision of ICD implantation guidelines to ultimately reduce the incidence of sudden cardiac death in HIV‐infected patients. Further studies are needed to assess the relative contribution of each of these mechanisms and risk factors.

Relationship between Endothelial Function, Antiretroviral Treatment and Cardiovascular Risk Factors in HIV Patients of African Descent in South Africa: A Cross-Sectional Study

Limited information on the effect of antiretroviral treatment (ART) on vascular function in South Africans of African descent living with human immunodeficiency virus (HIV) is available. The relationship between ART, vascular function and cardiovascular risk factors in South Africans of African ancestry with HIV was therefore studied. This cross-sectional study recruited 146 HIV-positive individuals on ART (HIV⁺ART⁺), 163 HIV-positive individuals not on ART (HIV⁺ART⁻) and 171 individuals without HIV (HIV⁻) in Mthatha, Eastern Cape Province of South Africa. Flow-mediated dilation (FMD) test was performed to assess endothelial function. Anthropometry and blood pressure parameters were measured. Lipid profile, glycaemic indices, serum creatinine as well as CD4 count and viral load were assayed in blood. Urinary albumin to creatinine ratio (ACR) was determined as a marker of cardiovascular risk. Obesity and albuminuria were positively associated with HIV, and HIV⁺ART⁺ participants had significantly higher HDL cholesterol. Dyslipidaemia markers were significantly higher in hypertensive HIV⁺ART⁺ participants compared with the controls (HIV⁺ART⁻ and HIV⁻ participants). FMD was not different between HIV⁺ART⁺ participants and the controls. Moreover, HIV⁺ART⁺ participants with higher FMD showed lower total cholesterol and LDL cholesterol comparable to that of HIV⁻ and HIV⁺ART⁻ participants. A positive relationship between FMD and CD4 count was observed in HIV⁺ART⁺ participants. In conclusion, antiretroviral treatment was associated with cardiovascular risk factors, particularly dyslipidaemia, in hypertensive South Africans of African ancestry with HIV. Although, ART was not associated with endothelial dysfunction, flow-mediated dilatation was positively associated with CD4 count in HIV-positive participants on ART.

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.

Promoting Cardiovascular Health in Patients Living with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome

Patients living with human immunodeficiency virus/acquired immunodeficiency syndrome (PLWHA) are at increased risk of cardiovascular disease because of advances in human immunodeficiency virus/acquired immunodeficiency syndrome treatment and increased life expectancy. Cardiovascular health promotion in PLWHA includes strategies for risk factor reduction, disease prevention, early detection, and treatment of cardiovascular disease.

Association of HIV-infection, antiretroviral treatment and metabolic syndrome with large artery stiffness: a cross-sectional study

Background

Effective combined antiretroviral therapy (cART) has improved life expectancy among people living with HIV-1 infection. Treated HIV-1infection increases the prevalence of metabolic syndrome (MS). Despite sub-Saharan Africa having among the highest rates of HIV-1 infection, the effects of MS in HIV-1-infected individuals on cardiovascular risk is poorly explored. The aim of the study was to assess whether MS and/or HIV-1 treatment correlates with large elastic artery stiffness in HIV-1-infected patients treated with first-line cART.

Methods

The study sample comprised of 102 subjects free of cardiovascular disease and major risk factors divided into two groups based on HIV-1 infection, treatment, and MS status: HIV-1⁺/cART⁺/MS⁺ (n = 12); HIV-1⁺/cART⁻/MS⁺ (n = 16); HIV-1⁻/ MS⁺ (n = 10); HIV-1⁺/cART⁺/MS⁻ (n = 42); HIV-1⁺/cART⁻/MS⁻ (n = 32); HIV-1⁻/ MS⁻ (n = 39). MS was established according the International Diabetes Federation definition. Large artery stiffness was measured using applanation tonometry to assess aortic pulse wave velocity (aPWV) and aortic augmentation index at heart rate of 75 bpm (AIx@HR75). cART included lamivudine/zidovudine and nevirapine or efavirenz.

Results

The prevalence of MS in the HIV-1-infected patients was 28%. There were no significant differences in aPWV in the non-MS groups. However, in subjects with MS, aPWV was significantly higher in the HIV-1 cART patients (9.0 ± 1.9 m/s) compared with both controls (7.5 ± 1.8 m/s; P = 0.018) and untreated HIV-1 patients (7.7 ± 1.3 m/s; P = 0.023), and these differences remained after adjustment for blood pressure and sex. Aortic PWV was significantly elevated (P = 0.009) in HIV-1 cART patients with MS compared to their counterparts without MS. Untreated HIV-1 patients with MS also demonstrated increased aPWV compared to their counterparts without MS (P = 0.05). Aortic AIx@HR75 was, on average, ~ 5% higher in HIV-1 cART patients with MS (28.3 ± 62% compared with untreated HIV-1 patients with MS (23.5 ± 9%; P = 0.075). Sub-group multivariate analysis identified MS as an independent predictor of increased aPWV in HIV-1 cART patients.

Conclusions

Our study established that presence of MS in HIV-1 patients on treatment was associated with increased aPWV and hence increased arterial stiffness in sub-Saharan African HIV-1 patients on first-line cART.

Microvascular Function in Aging Among Women Living with HIV

Combined antiretroviral therapy (CART) has turned HIV-infection to a treatable chronic disease during which many patients survive to middle and older age. However, they prematurely develop non-AIDS comorbidities such as cardiovascular disease, metabolic syndrome, diabetes, and HIV-associated neurocognitive disorders (HAND). Microcirculatory changes and endothelial dysfunction occur early both in HIV-infected and in aging patients, in whom they usually precede cardiovascular and neurocognitive impairments. Also, mild cognitive involvement has been reported in women during the menopausal transition. Disruption of the blood-brain barrier, as well as microvascular and cerebral blood flow changes, has been reported in HIV patients with HAND, including postmenopausal women. However, most studies addressing this issue included women aged less than 50 years. Whether HIV-infected women growing older with CART would be subsequently exposed to an increased progression of cognitive impairment overtime remains unknown.

Cross-sectional imaging of aortic infections

Aortic infections are uncommon clinical entities, but are associated with high rates of morbidity and mortality. In this review, we focus on the cross-sectional imaging appearance of aortic infections, including aortic valve endocarditis, pyogenic aortitis, mycotic aneurysm and aortic graft infections, with an emphasis on CT, MRI and PET/CT appearance. Teaching Points • Aortic infections are associated with high morbidity and mortality. • CT, MRI and FDG PET/CT play complementary roles in aortic infection imaging. • Radiologists should be vigilant for aortic infection manifestations to ensure timely diagnosis.

Enhanced autophagy in pulmonary endothelial cells on exposure to HIV-Tat and morphine: Role in HIV-related pulmonary arterial hypertension

Intravenous drug use is one of the major risk factors for HIV-infection in HIV-related pulmonary arterial hypertension patients. We previously demonstrated exaggerated pulmonary vascular remodeling with enhanced apoptosis followed by increased proliferation of pulmonary endothelial cells on simultaneous exposure to both opioids and HIV protein(s). Here we hypothesize that the exacerbation of autophagy may be involved in the switching of endothelial cells from an early apoptotic state to later hyper-proliferative state. Treatment of human pulmonary microvascular endothelial cells (HPMECs) with both the HIV-protein Tat and morphine resulted in an oxidative stress-dependent increase in the expression of various markers of autophagy and formation of autophagosomes when compared to either Tat or morphine monotreatments as demonstrated by western blot, transmission electron microscopy and immunofluorescence. Autophagy flux experiments suggested increased formation rather than decreased clearance of autolysosomes. Inhibition of autophagy resulted in a significant increase in apoptosis and reduction in proliferation of HPMECs with combined morphine and Tat (M+T) treatment compared to monotreatments whereas stimulation of autophagy resulted in opposite effects. Significant increases in the expression of autophagy markers as well as the number of autophagosomes and autolysosomes was observed in the lungs of SIV-infected macaques and HIV-infected humans exposed to opioids. Overall our findings indicate that morphine in combination with viral protein(s) results in the induction of autophagy in pulmonary endothelial cells that may lead to an increase in severity of angio-proliferative remodeling of the pulmonary vasculature on simian and human immunodeficiency virus infection in the presence of opioids.

Population-Based Estimates of Life Expectancy After HIV Diagnosis: United States 2008-2011

INTRODUCTION

Using National HIV surveillance system data, we estimated life expectancy and average years of life lost (AYLL) among persons diagnosed with HIV infection during 2008-2011.

METHODS

Population-based surveillance data, restricted to persons with diagnosed HIV infection aged 13 years or older, from all 50 states and Washington, D.C. were used to estimate life expectancy after HIV diagnosis using the life table method. Generated estimates were compared with life expectancy in the general population in the same calendar year to calculate AYLL. Life expectancy and AYLL were also estimated for subgroups by age, sex, and race/ethnicity.

RESULTS

The overall life expectancy after HIV diagnosis in the United States increased by 3.43 years from 25.43 (95% CI: 25.37 to 25.49) in 2008 to 28.86 (95% CI: 28.80 to 28.92) in 2011. Improvements were observed irrespective of sex, race/ethnicity, transmission category, and stage of disease at diagnosis, though the extent of improvement varied by different characteristics. Based on the life expectancy in the general population, in 2010, the AYLL were 12.8 years for males and 16.5 years for females. By race/ethnicity, on average, blacks (13.3 years) and whites (13.4 years) had fewer AYLL than Hispanics/Latinos (14.7).

CONCLUSIONS

Despite improvements in life expectancy among people diagnosed with an HIV infection during 2008-2011, disparities by sex and by race/ethnicity persist. Targeted efforts should continue to further reduce disparities and improve life expectancy after HIV diagnosis.

Drug therapies for HIV-related metabolic disorders

INTRODUCTION

Human immunodeficiency virus (HIV) has become a chronic disease often associated with dyslipidaemia and insulin resistance. Combination antiretroviral therapy (cART) may contribute to metabolic disturbances, eventually leading to increased cardiovascular disease (CVR) in this population. Escalating interventions to decrease CVR include promoting a healthy lifestyle, such as quitting smoking, diet and regular exercise. If they do not achieve the goals, a change of cART should be considered, followed by or used concomitantly with the use of chemical therapies.

AREAS COVERED

The aim of this article is to review the available drug therapies for the treatment of metabolic disorders in HIV-infected patients and to examine their safety and effectiveness in this population. A review of the literature was conducted, highlighting the most relevant articles.

EXPERT OPINION

Switching strategies can be useful but its expected benefit is not high. Therefore, chemical intervention is often needed. Statins have been proven to reduce CVR in the general population and in HIV-infected patients. Simvastatin is contraindicated in patients treated with boosted PI due to interactions; atorvastatin is safe at submaximal dose and needs close monitoring, while pravastatin lacks lipid-lowering potency, and rosuvastatin and pitavastatin are safe. Ezetimibe and fibrates are also safe and effective in HIV-infected patients and can be used in combination with statins. The management of glucose homeostatic disorders in HIV-infected patients follows the same guidelines as in the general population. However, there are specific considerations with respect to the interactions of particular medications with cART. When drug therapy is needed, metformin is the first-line drug. Decisions regarding second- and third-line drugs should be carefully individualized.

Angiogenic, lymphangiogenic and adipogenic effects of HIV-1 matrix protein p17

Lymphangiogenesis and concurrent angiogenesis are essential in supporting proliferation and survival of AIDS-related lymphomas, which are often metastatic. In vitro studies suggest a candidate angiogienic and lymphangiogenic factor encoded by HIV: the matrix protein p17. p17 accumulates in lymph nodes of patients even when they are undergoing highly active antiretroviral therapy. p17 has been found to affect immune cells, and recent data showed that a variant p17, called S75X, induces cell growth by triggering MAPK/ERK and PI3K/AKT pathways. We tested the in vivo angiogenic activity of p17 by injecting it in Matrigel plugs in nude mice. Plugs were retrieved 7 days after injection, and assessed macroscopically, and by light and confocal microscopy. Our data revealed that both reference and S75X variant p17 promote angiogenesis and lymphangiogenesis in vivo. Our results suggest that the induction of angiogenesis and lymphangiogenesis by HIV-1 p17 may generate a favorable microenvironment that could trigger tumor growth and maintenance. Moreover, the presence of adipocytes infiltration observed at the histological level suggests a possible interplay between angiogenesis, lymphangiogenesis and adipogenesis. These findings offer new opportunities for the development of treatment strategies to combat HIV-related cancers.

HIV-associated pulmonary arterial hypertension: from bedside to the future

Pulmonary arterial hypertension (PAH) is a life-threatening complication of HIV infection. The prevalence of HIV-associated PAH (HIV-PAH) seems not to be changed over time, regardless of the introduction of highly active antiretroviral therapy (HAART). In comparison with the incidence of idiopathic PAH in the general population (1-2 per million), HIV-infected patients have a 2500-fold increased risk of developing PAH. HIV-PAH treatment is similar to that for all PAH conditions and includes lifestyle changes, general treatments and specific treatments.

Cardiovascular disease in human immunodeficiency virus-infection as a cause of hospitalization: a case-series in a General Hospital in Peru

Background

Cardiovascular disease in the context of human immunodeficiency virus infection has become a major clinical concern in recent years. In the current report we assess hospitalizations due to cardiovascular disease in human immunodeficiency virus patients in a Social Security reference hospital in Peru.

Methods

A retrospective study was carried out between January 1996 and December 2012 in a General Hospital in Lima, Peru.

Results

We included 26 patients hospitalized due to cardiovascular disease. Mean age was 46.3 years (SD 12.5), predominantly male (57.7%). Ten patients (38.4%) were in Acquired Immunodeficiency Syndrome stages. Seventeen (65.4%) received high-active-antiretroviral therapy. Eleven (42.3%) had cardiac involvement and 15 (57.7%) had non-cardiac vascular involvement. The most frequent causes of cardiac involvement were pericardial effusion and myocardial infarction. On the other hand, deep vein thrombosis and stroke were the most frequent for non-cardiac vascular involvement.

Conclusions

Cardiovascular disease is an important cause of hospitalization in Peruvian human immunodeficiency virus patients, with differences between immunosuppression stages. Further studies analyzing associated factors are warranted.

Proposed research plan for the derivation of a new Cardiac Risk Index

The Revised Cardiac Risk Index (RCRI) was incorporated into the American College of Cardiology/American Heart Association (ACC/AHA) recommendations for the preoperative evaluation of the cardiac patient for noncardiac surgery. The purpose of this review was to analyze studies on cardiovascular clinical risk prediction that had used the previous "standard best" model, the RCRI, as a comparator. This review aims to determine whether modification of the current risk factors or adoption of other risk factors or other risk indices would improve upon the discrimination of cardiac risk prediction when compared with the RCRI. This is necessary because recent risk prediction models have shown better discrimination for major adverse cardiac events, and the pre-eminence of the RCRI is now in question. There is now a need for a new "best standard" cardiovascular risk prediction model to supersede the RCRI. This is desirable because it would: (1) allow for a global standard of cardiovascular risk assessment; (2) provide a standard comparator in all risk prediction research; (3) result in comparable data collection; and (4) allow for individual patient data meta-analyses. This should lead to continued progress in cardiovascular clinical risk prediction. A review of the current evidence suggests that to improve the preoperative clinical risk stratification for adverse cardiac events, a new risk stratification model be built that maintains the clinical risk factors identified in the RCRI, with the following modifications: (1) additional glomerular filtration rate cut points (as opposed to a single creatinine cut point); (2) age; (3) a history of peripheral vascular disease; (4) functional capacity; and (5) a specific surgical procedural category. One would expect a substantial improvement in the discrimination of the RCRI with this approach. Although most noncardiac surgeries will benefit from a standard "generic" cardiovascular risk prediction model, there are data to suggest that patients with human immunodeficiency virus disease who are undergoing vascular surgery may benefit from specific cardiovascular risk prediction models.

HIV-associated large-vessel vasculopathy: a review of the current and emerging clinicopathological spectrum in vascular surgical practice

An established relationship exists between human immunodeficiency virus (HIV) and the vascular system, which is characterised by clinical expressions of aneurysmal and occlusive disease that emanate from a common pathological process. The exact pathogenesis is currently unknown; attempts to implicate opportunistic pathogens have been futile. Theories converge on leucocytoclastic vasculitis with the vaso vasora as the vasculopathic epicentre. It is thought that the virus itself or viral proteins trigger the release of inflammatory mediators that cause endothelial dysfunction and smooth muscle proliferation leading to vascular injury and thrombosis. The beneficial effects of highly active anti-retroviral therapy alter the natural history of the disease profile and promote longevity but are negated by cardiovascular complications. Atherosclerosis is an emerging challenge. Presently patients are managed by standard surgical protocols because of non-existent universal surgical interventional guidelines. Clinical response to treatment is variable and often compounded by complications of graft occlusion, sepsis and poor wound healing. The clinical, imaging and pathological observations position HIV-associated large-vessel vasculopathy as a unique entity. This review highlights the spectrum of HIV-associated large-vessel aneurysmal, occlusive and atherosclerotic disease in vascular surgical practice.

Cardiovascular manifestations of HIV infection in children

BACKGROUND

HIV infection in children is now considered as a chronic condition, in which various non-infectious complications may occur, including those affecting the developing cardiovascular system. As children are expected to survive well into adulthood, understanding childhood as well as potential future cardiovascular complications is of major importance.

METHODS AND RESULTS

We reviewed published literature on childhood cardiac manifestations and longer term effects of pediatric HIV infection on the cardiovascular system. Evidence gaps that should be prioritized in research are highlighted. Through poorly understood mechanisms, HIV infection may cause various cardiac complications already manifesting in childhood, such as structural and functional myocardial derangements, pulmonary hypertension, pericardial effusion and possibly endocarditis. Evidence indicates that HIV infection in children also has unfavorable effects on the vasculature and cardiovascular biomarkers, such as increased intima-media thickness and decreased flow-mediated dilation, a marker of endothelial function. However, studies are small and predominantly include antiretroviral therapy-treated children, so that it is difficult to differentiate between effects of HIV infection per se and antiretroviral therapy treatment, reported in adults to have cardiovascular side effects.

CONCLUSIONS

HIV infection in children may greatly impact the cardiovascular system, including effects on the heart, which tend to manifest early in childhood, and on the vasculature. The underlying mechanisms, essential for targeted prevention, are poorly understood. Current evidence largely stems from research in adults. However, as modes of infection, immune maturity, growth and development, and treatment are markedly different in children, specific pediatric research, accounting for the complex interplay of normal growth and development, HIV infection and treatment, is clearly warranted.

Large vessel adventitial vasculitis characterizes patients with critical lower limb ischemia with as compared to without human immunodeficiency virus infection

Objectives

Whether a human immunodeficiency virus (HIV)-associated vasculitis in-part accounts for occlusive large artery disease remains uncertain. We aimed to identify the histopathological features that characterize large vessel changes in HIV sero-positive as compared to sero-negative patients with critical lower limb ischemia (CLI).

Materials and Methods

Femoral arteries obtained from 10 HIV positive and 10 HIV negative black African male patients admitted to a single vascular unit with CLI requiring above knee amputation were subjected to histopathological assessment. None of the HIV positive patients were receiving antiretroviral therapy.

Results

As compared to HIV negative patients with CLI, HIV positive patients were younger (p<0.01) and had a lower prevalence of hypertension (10 vs 90%, p<0.005) and diabetes mellitus (0 vs 50%, p<0.05), but a similar proportion of patients previously or currently smoked (80 vs 60%). 90% of HIV positive patients, but no HIV negative patient had evidence of adventitial leukocytoclastic vasculitis of the vasa vasorum (p<0.0001). In addition, 70% of HIV positive, but no HIV negative patient had evidence of adventitial slit-like vessels. Whilst T-lymphocytes were noted in the adventitia in 80% of HIV positive patients, T-lymphocytes were noted only in the intima in HIV negative patients. The presence of femoral artery calcified multilayered fibro-atheroma was noted in 40% of HIV positive and 90% of HIV negative patients with CLI.

Conclusions

An adventitial vasculitis which characterizes large artery changes in CLI in HIV-infected as compared to non-infected patients, may contribute toward HIV-associated occlusive large artery disease.

HIV, vascular surgery and cardiovascular outcomes: a South African cohort study

Risk factors for peri-operative cardiac morbidity are poorly described in HIV-positive patients. This prospective observational study describes cardiovascular risk factors in a cohort of vascular surgical patients of known HIV status. We recruited 225 patients with 73 (32%) being HIV-positive. When compared with HIV-negative patients, the HIV-positive patients were younger (mean (SD) 56.4 (13.3) vs 40.5 (10.4) years, respectively, p < 0.01). They had fewer Revised Cardiac Risk Index cardiovascular risk factors (median (range [IQR]) 1 (0-5 [0-2]) vs 0 (0-2 [0-0]), respectively, p < 0.001), with the exception of congestive cardiac failure (p = 0.23) and renal dysfunction (p = 0.32), and so were of a significantly lower Revised Cardiac Risk Index risk category (p < 0.01). HIV-positive and -negative patients had similar outcomes in: 30-day mortality (p = 0.78); three-day postoperative troponin leak (p = 0.66); and a composite outcome of mortality and troponin release (p = 0.69). We conclude that although HIV-positive patients have fewer cardiovascular risk factors, they have similar peri-operative major adverse cardiac events to HIV-negative patients. Research should focus on why this is the case, and if alternative clinical risk predictors can be developed for HIV patients.

Metformin: a cheap and well-tolerated drug that provides benefits for viral infections

OBJECTIVES

Insulin resistance in viral infections is common. We have explored the effectiveness of metformin for alleviating insulin resistance in HIV-infected patients and assessed the relevance of the ataxia-telangiectasia mutated (ATM) rs11212617 variant in the clinical response with the rationale that metformin modulates cellular bioenergetics in an ATM-dependent process.

METHODS

HIV-infected patients (n = 385) were compared with controls recruited from the general population (n = 300) with respect to the genotype distribution of the ATM rs11212617 variant and its influence on selected metabolic and inflammatory variables. We also followed up a subset of male patients with HIV and hepatitis C virus (HCV) coinfection (n = 47) who were not receiving antiviral treatment and for whom metformin was prescribed for insulin resistance, which tends to have a higher incidence and severity in coinfected patients.

RESULTS

Among the HIV-infected patients, human cytomegalovirus (91.9%) and HCV (62.3%) coinfections were frequent. Selected metabolic and/or inflammatory variables were significantly altered in infected patients. Treatment with metformin in HIV and HCV coinfected patients was well tolerated and significantly increased the sensitivity of peripheral tissues to insulin. The minor allele (C) of the rs11212617 variant was associated with treatment success and may affect the course of insulin resistance in response to metformin (odds ratio 1.21; 95% confidence interval 1.07-1.39; P = 0.005). There were no differences between treated and untreated patients in viral loads or variables measuring immune defence, indicating that toxicity is unlikely.

CONCLUSIONS

We provide novel data suggesting that identification of the ATM rs11212617 variant may be important in assessing the glycaemic response to metformin treatment for insulin resistance in HIV-infected patients.

Metabolic disorders and cardiovascular consequences of HIV infection and antiretroviral therapy

Metabolic disturbances associated with HIV disease have become an important factor in patient management and have important implications for long-term outcomes, both in regards to mortality and healthcare burden. Recent research has implicated both HIV infection itself and specific antiretroviral therapies in the development of these disorders. This review examines recent findings from research into insulin and glucose dysregulation, serum lipid abnormalities, adipose tissue and derangements in bone metabolism. This review then describes the cardiovascular consequences and management of these metabolic disorders, and summarizes current thinking on the pathogenesis and effects of antiretroviral therapy. Finally, the review raises some questions regarding ongoing challenges and unmet needs in this field of research.

HIV-1 matrix protein p17 promotes angiogenesis via chemokine receptors CXCR1 and CXCR2

Vascular diseases supported by aberrant angiogenesis have increased incidence in HIV-1-infected patients. Several data suggest that endothelium dysfunction relies on action of HIV-1 proteins rather than on a direct effect of the virus itself. The HIV-1 matrix protein p17 is known to deregulate the biological activity of different immune cells. Recently, p17 was found to mimic IL-8 chemokine activity by binding to the IL-8 receptor CXCR1. Here we show that p17 binds with high affinity to CXCR2, a CXCR1-related receptor, and promotes the formation of capillary-like structures on human endothelial cells (ECs) by interacting with both CXCR1 and CXCR2 expressed on the EC surface. ERK signaling via Akt was defined as the pathway responsible for p17-induced tube formation. Ex vivo and in vivo experimental models confirmed the provasculogenic activity of p17, which was comparable to that induced by VEGF-A. The hypothesis of a major role for p17 in HIV-1-induced aberrant angiogenesis is enforced by the finding that p17 is detected, as a single protein, in blood vessels of HIV-1-patients and in particular in the nucleus of ECs. Localization of p17 in the nucleus of ECs was evidenced also in in vitro experiments, suggesting the internalization of exogenous p17 in ECs by mechanisms of receptor-mediated endocytosis. Recognizing p17 interaction with CXCR1 and CXCR2 as the key event in sustaining EC aberrant angiogenesis could help us to identify new treatment strategies in combating AIDS-related vascular diseases.

[Pulmonary hypertension in patients infected with human immunodeficiency virus: current situation]

The increase in survival that has been achieved with the new treatments in the era of highly active antiretroviral therapy, has enabled clinicians and researchers to analyze issues that emerge in the long term in patients with HIV infection. Although the majority of cardiovascular complications have been widely described, the pathogenesis of pulmonary arterial hypertension is still poorly understood, and is one of the more complex and feared complications as it worsens the prognosis and quality of life of these patients This article reviews newer aspects related to the aetiology, symptoms, diagnosis and treatment of this disease.

Antihypertensive Drugs in Patients Treated with Antiretroviral

Objective:

To review the literature for information regarding pharmacokinetic interactions between antiretrovirals and antihypertensive agents, evaluate the clinical significance of these interactions, and analyze the effect of antihypertensive drugs on the metabolic complications frequently observed in HIV-infected patients to emphasize the advantages and inconveniences of every class of antihypertensive drugs in association with antiretrovirals.

Data Sources:

A literature search was conducted via PubMed and MEDLINE (1950-November 2011) using the search terms drug interactions, cytochrome P450, names of antiretrovirals, names of commonly prescribed antihypertensive drugs, pharmacokinetics, and metabolic complications. Reference citations from relevant publications, manufacturers’ product information, and www.HIV-druginteracttons.org were also reviewed.

Study Selection And Data Extractions:

All articles with an English abstract identified through the data search were examined. Of these, pharmacologic reviews, studies, and case reports were evaluated.

Data Synthesis:

Antihypertensive drugs interact with several antiretroviral drugs, non nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (Pls) in particular. Pharmacokinetic interactions are less expected with diuretics, jî-blockers excreted by the kidney, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin II receptor blockers (ARBs) other than losartan and irbesartan. Calcium channel blockers (CCBs) are metabolized by CYP3A4, with the potential for interaction with NNRTIs and Pls. Because CCBs do not adversely affect glucose or lipid metabolism or renal function, they may be preferred in patients with such complications. ACE inhibitors and ARBs may exert favorable effects on glucose homeostasis. In addition, they may significantly reduce protein excretion and further slow the progression of renal disease.

Conclusions:

The choice of antihypertensive drugs in HIV-infected patients is complex and must take into account the metabolic pathways of antiretroviral drugs and antihypertensive drugs with the potential of pharmacokinetic interactions, as well as the effect of antihypertensive drugs on some biological parameters.

Liver transplantation in human immunodeficiency virus-infected patients: procoagulant, but is antithrombotic prophylaxis required?

Liver transplantation (LT) for human immunodeficiency virus (HIV)-positive recipients with end-stage liver disease has become an accepted practice. However, because these patients are increasingly being recognized as prothrombotic, we reviewed their posttransplant thrombotic complications. Because morphological changes might be responsible in part for this prothrombotic state, we also conducted a histopathological review of explants from HIV-positive patients. Between 1990 and 2010, 24 of 3502 recipients (including 23 adults) were HIV-positive at LT. These patients and their postoperative courses were reviewed with a particular focus on vascular complications, risk factors, and outcomes. Another patient in whom HIV was detected 12 years after LT was also examined. Among the 24 HIV-positive LT recipients (17 males and 22 whole liver grafts; median age = 40 years), 5 developed arterial complications [including 3 cases of hepatic artery thrombosis (HAT), 1 case of generalized arteriopathy (on angiography), and 1 case of endoarteritis (on histological analysis)]. Multiple arterial anastomoses were performed in 8 of the 24 recipients, and HAT occurred twice within this anastomosis group. The outcomes of the 3 patients with HAT included retransplantation, biliary stenting for ischemic cholangiopathy followed by retransplantation, and observation only. In addition, 5 separate venous thrombotic events were detected in the 24 recipients during this period. Moreover, the delayed-HIV recipient developed delayed HAT and subsequently ischemic cholangiopathy and was being assessed for retransplantation at the time of this writing. In conclusion, the prothrombotic state associated with combined HIV and liver disease is a cause of morbidity after LT: 8 of the 24 recipients (33%) in this series suffered vascular thrombotic complications. There is a potential increase in the risk of HAT: the rate for the HIV-positive cohort was higher than the rate for historical HIV-negative controls [12% versus 3.2%, P = 0.016 (Fisher's exact test)]. The minimization of complex arterial reconstruction, coagulopathy screening, and risk-adapted antithrombotic chemoprophylaxis appear to be reasonable precautions.

Ritonavir inhibits the two main prasugrel bioactivation pathways in vitro: a potential drug-drug interaction in HIV patients

Prasugrel is an antiplatelet prodrug used in patients with acute coronary syndrome. Prasugrel is mainly bioactivated by cytochromes P450 3A4/5 and CYP2B6. HIV patients are at risk of cardiovascular disease, and the protease inhibitor ritonavir is a potent inhibitor of these 2 CYPs. The aim of this in vitro study was to determine the impact of ritonavir in prasugrel metabolism. Human liver microsomes (HLMs) and recombinant microsomes were used to identify the enzymes responsible for the bioactivation of prasugrel. Prasugrel concentrations of 5 to 200 μM were used for Km determination. Inhibition by ritonavir was characterized using HLMs at concentrations of 0.1 to 30 μM. Prasugrel active metabolite determination was performed with a validated liquid chromatography-mass spectrometry method. Using recombinant microsomes, prasugrel biotransformation was mainly performed by CYP2B6, CYP2D6, CYP2C19, CYP3A4, and CYP3A5. With specific inhibitors of CYP3A, CYP2B6, CYP2D6, CYP2C9, and CYP2C19, active metabolite production was decreased by 38% ± 15% with 4-(4-chlorobenzyl)pyridine (CYP2B6 inhibitor) and by 45 ± 16% with ketoconazole (CYP3A inhibitor). The Km value for prasugrel metabolism in HLMs was determined to be 92.5 μM. Ritonavir at 0.1 to 30 μM was shown to be a potent dose-dependent inhibitor of prasugrel. In this in-vitro study, we found a potent inhibition of prasugrel bioactivation by ritonavir compared to the specific inhibitors of CYP3A and CYP2B6 due to the simultaneous inhibition of CYP2B6 and CYP3A by ritonavir. This finding suggests a potential significant drug-drug interaction between these two drugs.

Antiretroviral treatment-induced dyslipidemia in HIV-infected patients is influenced by the APOC3-related rs10892151 polymorphism

Background

The recently observed association between the APOC3-related rs10892151 polymorphism and serum triglyceride levels has prompted us the possibility to explore whether this genetic variant may play a major role in human immunodeficiency virus (HIV)/antiretroviral therapy-induced dyslipidemia.

Methods

We determined the rs10892151 genotype distribution and serum apolipoprotein (apo) C-III concentration in a group of HIV-infected patients (n = 208) and in a group of age and sex-matched healthy volunteers (n = 200). Circulating lipid and lipoprotein levels were followed for 12 months after antiretroviral treatment initiation in the HIV-infected group.

Results

There were no significant variations in the frequency of the A allele between the healthy and HIV-infected groups (7.5 vs. 8.6%, respectively; p = 0.7); additionally, the A allele was not related to serum apo C-III concentration. However, among patients receiving protease inhibitor (PI) treatment, carriers of the A allele had significantly increased serum triglyceride (5.76 ± 2.54 mmol/L) and total cholesterol (6.63 ± 2.85 mmol/L) concentrations together with depressed levels of HDL-cholesterol (0.75 ± 0.3 mmol/L) when compared with patients not carrying the allele (2.43 ± 1.32, 5.2 ± 2.17 and 1.24 ± 0.4 mmol/L, respectively) at the end of the study. This effect was only evident for HDL-cholesterol concentration when patients were treated with non-nucleoside reverse transcriptase inhibitors (1.05 ± 0.4 vs. 1.28 ± 0.4 mmol/L).

Conclusions

The A allelic variant of the rs10892151 polymorphism is not associated with serum apo C-III concentration, but predisposes HIV-infected patients to less favorable lipid profile, particularly in those patients treated with PIs.

Cardiovascular complications of AIDS

PURPOSE OF REVIEW

The purpose of the present review article is to present the recent data on the cardiovascular complications in patients infected with HIV as well as the preventive strategies to reduce cardiovascular disease in those patients.

RECENT FINDINGS

Individuals infected with HIV frequently demonstrate a metabolic syndrome associated with atherosclerosis and cardiovascular disease. Extensive functional and structural arterial wall changes have been observed in these individuals. It is documented that these vascular changes are closely related to highly active antiretroviral treatment-induced metabolic disorders as well as characteristics of the HIV infection itself. Intensive treatment of vascular dysfunction might be helpful in preventing or retarding the atherosclerotic process in HIV patients.

SUMMARY

Marked changes in arterial function and structure are observed in HIV patients leading to increased cardiovascular morbidity and mortality. Early antiretroviral therapy and aggressive treatment of cardiovascular risk factors might be helpful.

Sustained virological response to interferon-α plus ribavirin decreases inflammation and endothelial dysfunction markers in HIV/HCV co-infected patients

OBJECTIVES

Hepatitis C virus (HCV) antiviral therapy might lead to decreased chronic immune activation and endothelial dysfunction associated with cardiovascular risk. The aim was to evaluate the effect of HCV eradication on serum markers of inflammation and endothelial dysfunction markers in HIV/HCV co-infected patients.

METHODS

We carried out a retrospective study of 69 HIV/HCV co-infected patients on interferon (IFN)-α plus ribavirin. In addition, 47 HIV-infected subjects were selected as a control group. A sustained virological response (SVR) was defined as an undetectable HCV viral load up to 24 weeks after the end of treatment. Tumour necrosis factor (TNF) receptor-1 (TNF-R1), soluble E-selectin (sE-selectin), soluble P-selectin (sP-selectin), soluble intercellular adhesion molecule 1 (sICAM-1) and soluble vascular cell adhesion molecule 1 (sVCAM-1) were measured using a multiplex immunoassay kit.

RESULTS

HIV/HCV co-infected patients had higher values of soluble TNF-R1 (sTNF-R1), sE-selectin and sICAM-1 than HIV mono-infected patients (P < 0.05). SVR patients had a decrease in sTNF-R1, sP-selectin, sE-selectin and sICAM-1 during anti-HCV treatment (P < 0.05) and, at the end of treatment, SVR patients had lower values of sTNF-R1, sE-selectin and sVCAM-1 than non-responder patients (P < 0.05), although the values of sTNF-R1, sP-selectin, sE-selectin and sICAM-1 remained higher than in HIV mono-infected patients (P < 0.05). Moreover, we found a significant positive relationship between an increase in sTNF-R1 and increases in sP-selectin, sE-selectin and sICAM-1 during anti-HCV therapy.

CONCLUSIONS

Chronic hepatitis C infection induces alterations of markers of inflammation and endothelial dysfunction. Eradication of HCV, following IFN-α and ribavirin therapy, reduces immune activation as well as markers of inflammation and endothelial dysfunction.

The role of postexercise measurements in the diagnosis of peripheral arterial disease in HIV-infected patients

Peripheral arterial disease (PAD) is a marker of atherosclerosis, which is not well studied in the population with human immunodeficiency virus (HIV). We prospectively enrolled HIV-infected patients who had normal resting ankle-brachial index (rABI) readings. All participants performed either a treadmill walking test (TT) or pedal plantar flexion test (PFT). Patients were divided into 2 groups according to postexercise changes; PAD and No-PAD group. The 2 groups were compared with regard to established cardiovascular disease risk factors and other HIV infection parameters. Peripheral arterial disease was present in 30 (26.5%) of 113 consecutive HIV-infected patients included in the study. Mean age was 47 ± 10 years. The risk factors studied did not differ significantly among the 2 groups except for male gender, which was significantly associated with PAD (RR: 4.15; CI: 1.6 to 11.1: P < .0008). The prevalence of PAD, diagnosed by significant drop in postexercise ABI and ankle pressure in patients with HIV is high.

Microcirculatory vascular dysfunction in HIV-1 infected patients receiving highly active antiretroviral therapy

OBJECTIVES

We investigated whether HIV-1 infected patients receiving highly active antiretroviral therapy (HAART) and HIV-1 infected patients who had never received HAART had differences in their vascular microcirculatory function.

METHODS

We assessed the forearm blood flow before and after four minutes of ischemic occlusion of the brachial artery using venous occlusion strain gauge plethysmography. The hyperaemic forearm blood flow was recorded for three minutes at 15 second intervals. We calculated the maximal percent increase of the forearm blood flow during hyperemia. Forty HIV-infected male patients receiving HAART were compared to 20 age- and BMI- matched, male HIV-infected patients who had never received HAART (control group).

RESULTS

Patients on HAART had similar baseline forearm blood flow but lower maximal and percentage (%) change in forearm blood flow than control patients (4.2 +/- 1.7 vs. 4.1 +/- 1.7 l/ 100mL/min P = 0.8, 32 +/- 11.2 vs. 38.9 +/- 10.5 l/100 mL/min. P = 0.04 and 714 +/- 255 vs. 907 +/- 325%, P = 0.01, respectively). Patients receiving HAART had higher cholesterol than control patients (221 +/- 58 vs. 163 +/- 38 mg/dL, P = 0.001). HAART was associated with the percentage change in the blood flow during hyperemia (coefficient regression B = -0.32, P = 0.02) after adjustment for age, cholesterol and viral load.

CONCLUSIONS

HIV-infected patients receiving HAART present abnormalities of arterial microcirculation in comparison with never-treated patients.

Infection with HIV and HCV enhances the release of fatty acid synthase into circulation: evidence for a novel indicator of viral infection

Background

Fatty acid synthase (FASN) is an enzyme synthesized by the liver and plays an important role in lipogenesis. The present study aimed to investigate whether serum FASN concentration may provide a direct link between HIV and/or HCV viral infections and lipid metabolic disorders commonly observed in HIV/HCV-infected patients.

Methods

We evaluated serum FASN concentration in 191 consecutive HIV-infected patients in the absence or presence of HCV co-infection. For comparison, 102 uninfected controls were included. Metabolic and inflammatory phenotype was also compared with respect to the presence of HCV co-infection.

Results

Serum FASN concentration was significantly higher in HIV-infected patients than in healthy participants and HCV co-infected patients showed higher levels than those without co-infection. Levels were also affected by treatment regimen, but marginally influenced by virological variables. Insulin concentration was the sole variable among metabolic parameters that demonstrated a significant correlation with serum FASN concentrations. Serum alanine aminotransferase (ALT) values correlated significantly with serum FASN concentration and provided the best discrimination with respect to the presence or absence of HCV co-infection. In multivariate analysis, only ALT, monocyte chemoattractant protein-1 (MCP-1) and the presence of antiretroviral treatment regimen significantly contributed to explain serum FASN concentration in HIV/HCV co-infected patients.

Conclusion

Serum FASN concentration is significantly increased in HIV-infected individuals. The release of FASN into the circulation is further enhanced in patients who are co-infected with HCV. Subsequent studies should explore the usefulness of this indicator to monitor the effect of viral infections on disease progression and survival.

The role of ERK1/2 signaling pathway in Nef protein upregulation of the expression of the intercellular adhesion molecule 1 in endothelial cells

Human immunodeficiency virus (HIV)-infected patients have increased rates of atherosclerotic cardiovascular diseases because the highly active antiretroviral therapy (HAART) decreased the morbidity and mortality of the disease. Endothelial dysfunction is possibly the most plausible link between HIV infection and related expression of cell adhesion molecules such as intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) on the endothelial cells. HIV-1 accessory protein negative regulate factor (Nef) has been shown to be very important for high virus replication and disease progression. Nef could upregulate the expression of ICAM-1 in the pathogenesis of HIV infection. Here, we provide evidence that the HIV-1 Nef can transcriptionally induce the expression of ICAM-1 in stable expressed Nef vascular endothelial cells. Nef-induced ICAM-1 upregulation requires the activation of the downstream kinase extracellular signal-regulated kinase (ERK). Flow cytometry (FCM) results showed that the percentage of ICAM-1 positive cells in Nef-expressed cells and control cells was (35.3% +/- 2.2%) and (12.5% +/- 0.8%), respectively (P < .01). Furthermore, inhibition of Nef activity by ERK mitogen-activated protein kinase (MAPK) inhibitor effectively blocked ICAM-1 upregulation, suggesting that ERK MAPK activation is an important initiating event in Nef-mediated ICAM-1 expression in Nef-expressed cells. These data demonstrate an important signaling event of Nef in HIV-1 pathogenesis.

Impaired diastolic function in naïve untreated human immunodeficiency virus infected patients

AIM

To evaluate cardiac function and structure in untreated human immunodeficiency virus (HIV) patients without clinical evidence of cardiovascular disease.

METHODS

Fifty-three naïve untreated HIV-infected patients and 56 healthy control subjects underwent clinical assessment, electrocardiography (ECG) and echocardiography, including tissue doppler imaging. Moreover, a set of laboratory parameters was obtained from all subjects, including HIV-RNA plasma levels, CD4 cell counts and tumor necrosis factor-α levels.

RESULTS

The two groups showed normal ECG traces and no differences regarding systolic morphologic parameters. In contrast, a higher prevalence of left ventricular diastolic dysfunction (abnormal relaxation or pseudonormal filling pattern) was found in the HIV patients (36% vs 9% in patients and controls, respectively, P <0.001).

CONCLUSION

Subclinical cardiac abnormalities appear in an early stage of the HIV infection, independent of antiretroviral therapy. The data suggest that HIV per se plays a role in the genesis of diastolic dysfunction.