Coronary artery disease and HIV; getting to the HAART of the matter

HIV-Related Myocardial Fibrosis: Inflammatory Hypothesis and Crucial Role of Immune Cells Dysregulation

Although the underlying mechanisms driving human immunodeficiency virus (HIV)-mediated cardiovascular diseases (CVD) onset and progression remain unclear, the role of chronic immune activation as a significant mediator is increasingly being highlighted. Chronic inflammation is a characteristic feature of CVD and considered a contributor to diastolic dysfunction, heart failure, and sudden cardiac death. This can trigger downstream effects that result in the increased release of pro-coagulant, pro-fibrotic, and pro-inflammatory cytokines. Subsequently, this can lead to an enhanced thrombotic state (by platelet activation), endothelial dysfunction, and myocardial fibrosis. Of note, recent studies have revealed that myocardial fibrosis is emerging as a mediator of HIV-related CVD. Together, such factors can eventually result in systolic and diastolic dysfunction, and an increased risk for CVD. In light of this, the current review article will focus on (a) the contributions of a chronic inflammatory state and persistent immune activation, and (b) the role of immune cells (mainly platelets) and cardiac fibrosis in terms of HIV-related CVD onset/progression. It is our opinion that such a focus may lead to the development of promising therapeutic targets for the treatment and management of CVD in HIV-positive patients.

Trends and perioperative outcomes of patients with human immunodeficiency virus (HIV) undergoing lower extremity revascularization

The development of highly active antiretroviral therapy (HAART) has significantly improved the life expectancy of patients with human immunodeficiency virus (HIV), but has led to the rise of chronic conditions including peripheral artery disease (PAD). However, trends and outcomes among patients with HIV undergoing lower extremity revascularization are poorly characterized. The aim of this study was to investigate the trends and perioperative outcomes of lower extremity revascularization among patients with HIV and PAD in a national database. The National Inpatient Sample (NIS) was reviewed between 2003 and 2014. All hospital admissions with a diagnosis of PAD undergoing lower extremity revascularization were stratified based on HIV status. Outcomes were assessed using propensity score matching and multivariable regression. Among all patients undergoing lower extremity revascularization for PAD, there was a significant increase in the proportion of patients with HIV from 0.21% in 2003 to 0.52% in 2014 (p < 0.01). Patients with HIV were more likely to be younger, male, and have fewer comorbidities, including coronary artery disease and diabetes, at the time of intervention compared to patients without HIV. With propensity score matching and multivariable regression, HIV status was associated with increased total hospital costs, but not length of stay, major amputation, or mortality. Patients with HIV with PAD who undergo revascularization are younger with fewer comorbidities, but have increased hospital costs compared to those without HIV. Lower extremity revascularization for PAD is safe for patients with HIV without increased risk of in-hospital major amputation or mortality, and continues to increase each year.

Radionuclide imaging of inflammation in atherosclerotic vascular disease among people living with HIV infection: current practice and future perspective

People living with human immunodeficiency virus (HIV) infection have twice the risk of atherosclerotic vascular disease compared with non-infected individuals. Inflammation plays a critical role in the development and progression of atherosclerotic vascular disease. Therapies targeting inflammation irrespective of serum lipid levels have been shown to be effective in preventing the occurrence of CVD. Radionuclide imaging is a viable method for evaluating arterial inflammation. This evaluation is useful in quantifying CVD risk and for assessing the effectiveness of anti-inflammatory treatment. The most tested radionuclide method for quantifying arterial inflammation among people living with HIV infection has been with F-18 FDG PET/CT. The level of arterial uptake of F-18 FDG correlates with vascular inflammation and with the risk of development and progression of atherosclerotic disease. Several limitations exist to the use of F-18 FDG for PET quantification of arterial inflammation. Many targets expressed on macrophage, a significant player in arterial inflammation, have the potential for use in evaluating arterial inflammation among people living with HIV infection. The review describes the clinical utility of F-18 FDG PET/CT in assessing arterial inflammation as a risk for atherosclerotic disease among people living with HIV infection. It also outlines potential newer probes that may quantify arterial inflammation in the HIV-infected population by targeting different proteins expressed on macrophages.

Treatment with a fixed dose combination antiretroviral therapy drug containing tenofovir, emtricitabine and efavirenz is associated with cardioprotection in high calorie diet-induced obese rats

HIV-infection, certain antiretroviral drug classes, especially protease inhibitors (PI), and obesity are associated with increased ischaemic heart disease (IHD) risk. However, the effect of PI-free fixed dose combination (FDC) antiretroviral therapy (ART) on hearts exposed to ischaemia-reperfusion injury (I/R) is unknown, particularly in obesity. This is becoming relevant as World Health Organisation guidelines recommend a FDC ART containing (non-) nucleoside reverse transcriptase inhibitors (tenofovir (TDF), emtricitabine (FTC) and efavirenz (EFV)) as first-line HIV treatment. Additionally, obesity rates are rising in HIV-infected populations, not only in ART-experienced individuals, but also at the time of ART initiation, which may further increase the risk of IHD. Therefore, we investigated the effects of PI-free FDC ART in myocardial I/R-exposed hearts from obese rats. Obesity was induced in male wistar rats via a 16-week high calorie diet. At week 10, treatment with a FDC ART drug containing TDF/FTC/EFV was initiated. Biometric and metabolic parameters, as well as myocardial functional recovery and infract size (IS), and myocardial signalling proteins following I/R were assessed after 16 weeks. Obese rats presented with increased body and intraperitoneal fat mass, elevated triglyceride and TBARS levels, whilst the hearts responded to I/R with impaired functional performance and increased IS. The FDC ART treatment did not alter biometric and metabolic parameters in obese rats. In a novel finding, ART protected obese hearts against I/R as shown by improved functional performance and smaller IS vs. untreated obese hearts. Cardioprotection was underscored by increased myocardial phosphorylated endothelial nitric oxide synthase (eNOS) and reduced AMP-kinase levels. In conclusion, these results demonstrate for the first time, that 6-weeks treatment of obese rats with a FDC ART drug specifically containing TDF/FTC/EFV conferred cardioprotection against I/R. The FDC ART-induced cardioprotection was seemingly unrelated to metabolic changes, but rather due to direct cardiac mechanisms including the up-regulation of myocardial eNOS.

Prevalence, Incidence, and Contributors of Subclinical Atheromatosis, Arteriosclerosis, and Arterial Hypertrophy in HIV-Infected Individuals: A Single-Center, 3-Year Prospective Study

Cardiovascular disease (CVD) is an important comorbidity for people living with HIV infection (PLWH) in the combined antiretroviral therapy era. We prospectively examined the presence of subclinical arterial disease in 138 consecutive CVD-free, HIV-infected individuals compared to 664 HIV-negative individuals. We studied 10 arterial sites in 4 beds using 5 distinct biomarkers of subclinical atheromatosis, arteriosclerosis, and hypertrophy and evaluated the association of subclinical arterial damage with CVD-related and HIV-related factors at baseline and at 3-year follow-up. Atheromatosis, arteriosclerosis, and arterial hypertrophy were present in 36.1%, 59.7%, and 34.3% of HIV-infected individuals, respectively, at baseline. HIV infection was independently associated with carotid atheromatosis and hypertrophy. The presence of carotid atheromatosis was independently associated with age, years of smoking, and exposure to nonnucleoside reverse transcriptase inhibitors (NNRTIs). The annual incidence of atheromatosis, arteriosclerosis, and arterial hypertrophy was 5.5, 18.6, and 12.5 cases/100 patients, respectively. Carotid atheromatosis progression was significantly associated with NNRTI exposure. People living with HIV infection exhibited high prevalence and incidence of subclinical arterial damage and site-specific predilection for the carotids. These investigations may help optimize HIV-specific CVD prediction models. The NNRTIs may contribute to atheromatosis, emphasizing the need to consider the atherogenic potential of antiretroviral drugs in management strategies.

Cardiovascular Disease in the Setting of Human Immunodeficiency Virus Infection

Background:

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

Objective:

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

Methods:

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

Results:

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

Conclusion:

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

Effect of aspirin treatment on abacavir-associated platelet hyperreactivity in HIV-infected patients

BACKGROUND

Ischemic cardiovascular events are a relevant cause of morbidity and mortality in HIV-infected patients. Use of abacavir (ABC), a nucleoside analog reverse transcriptase inhibitor, has been associated with increased risk of myocardial infarction (MI) and with platelet hyperreactivity. We explored whether low-dose aspirin reduces in vivo platelet activation and platelet hyperreactivity induced by ABC in HIV-infected subjects.

METHODS AND RESULTS

In a randomized, placebo-controlled, cross-over study forty HIV-infected patients with ABC-associated platelet hyperreactivity, defined by a score based on laboratory variables reflecting in vivo platelet activation and ex vivo platelet hyperresponsiveness, were randomized to aspirin 100 mg daily for 15 days with subsequent cross-over to placebo for additional 15 days or placebo for 15 days with subsequent cross-over to aspirin for further 15 days. In vivo and ex vivo platelet activation markers were measured at day 15 and 30. One group of healthy subjects, one of untreated HIV infected-patients and one treated without ABC, were studied concomitantly. Serum TxB₂ and urinary 11-dehydro-TxB₂ were decreased by aspirin in ABC-treated patients, but not as much as in healthy controls. Aspirin therapy reduced significantly platelet hyperreactivity (score: from 9.3, 95% CIs 8.7 to 10.0, to 7.5, 6.9 to 8.0), however without bringing it back to the levels of healthy controls (score: 4.6, 95% CIs 3.6 to 5.6).

CONCLUSION

Aspirin reduces ABC-induced in vivo platelet activation and platelet hyperreactivity in HIV-infected patients, however without normalizing them. Whether the observed reduction of platelet activation is sufficient to prevent cardiovascular events requires a prospective trial.

Inflammatory Markers and Plasma Lipids in HIV Patients: A Correlation Analysis Study

Background

Recent evidence suggests that HIV infection, even with treatment, increases the risk of coronary heart disease (CHD) and that both chronic inflammation and traditional risk factors play key roles in HIV-associated CHD.

Subjects and Methods

Patients (N=152), attending Harare HIV clinic, 26% of them male and 82% of them on antiretroviral therapy (ART), were studied. Inflammatory markers comprising of cytokines such as pro-inflammatory tumor necrosis factor-α, (TNF-α), anti-inflammatory interleukin 10, (IL-10) and highly sensitive C reactive protein (hsCRP) together with lipids were assayed using enzyme linked immunosorbent assay (ELISA), immuno-turbidimetric and enzymatic assays, respectively. Correlation analysis of inflammatory markers versus lipid profiles was carried out using bivariate regression analysis.

Results

Anti-inflammatory cytokine IL-10 and inflammatory hsCRP levels were elevated when measured in all the HIV positive patients, while TNF-α and lipid levels were within normal ranges. Pro-inflammatory TNF-α was significantly higher in ART-naive patients than ART-experienced patients, whereas the reverse was observed for anti-inflammatory IL-10 and anti-atherogenic HDL-C. Correlation analysis indicated a significant positive linear association between IL-10 and total cholesterol (TC) levels but no other correlations were found.

Conclusion

High cytokine ratio (TNF-α/IL-10) indicates higher CHD risk in ART-naive patients compared to the ART-exposed. The CHD risk could be further strengthened by interplay between inflammatory markers and high prevalence of low HDL-C. Lack of correlation between pro-inflammatory markers (hsCRP and TNF-α) with lipid fractions and correlation between anti-inflammatory IL-10 with artherogenic TC were unexpected findings, necessitating further studies in future.

Assessment of the atrial electromechanical properties of patients with human immunodeficiency virus

The relationship between atrial fibrillation and human immunodeficiency virus (HIV) infection was evaluated. Electro-echocardiographic methods can be used to predict the development of atrial fibrillation (AF). In this study, we aimed to investigate the atrial electromechanical delay (AEMD) parameters of HIV (+) patients. Forty-two HIV (+) patients and 40 HIV (-) healthy volunteers were prospectively enrolled in this study. The electromechanical properties of the subjects' atria were evaluated with tissue Doppler imaging. The left-AEMD, right-AEMD and inter-AEMD were increased in the HIV (+) patients relative to the controls (p=0.003, p<0.001, and p<0.001, respectively). The CD4 count was inversely correlated with the inter-AEMD (r=-0.428, p<0.001). The CD4 count was an independent predictor of the inter-AEMD (β=0.523, p=0.007). Our study demonstrated that both the inter- and intra-atrial electromechanical delays were prolonged in the patients with HIV. This non-invasive and simple technique may provide significant contributions to the assessment of the risk of atrial arrhythmia in patients with HIV.

Association between human immunodeficiency virus infection and arterial stiffness in children

Background Human immunodeficiency virus infection (HIV) is associated with increased cardiovascular risk and adverse cardiovascular outcome in adults. Early recognition of changes in vascular properties might prove essential in cardiovascular prevention in HIV-infected patients. We investigated the relations between HIV infection and arterial stiffness in children. Methods This cross-sectional study included 51 HIV-infected and 52 healthy children (age 3.2-14.5 years, 49 males). All infected children had acquired HIV by vertical transmission and were receiving antiretroviral therapy at time of assessment. Arterial stiffness was measured by pulse wave velocity and aortic augmentation index, using the Arteriograph system (Tensiomed Kft, Budapest, Hungary). We applied multivariable general linear modeling to evaluate the relationship between HIV infection and arterial stiffness with further adjustment for confounders and possible intermediary variables. Findings represent mean group differences with 95% confidence intervals and p values. Results Aortic augmentation index was higher by 9.0% (5.6-12.5, p < 0.001) in HIV-infected than in healthy children. Adjustment for blood pressure, protease inhibitor use, biomarkers for level of inflammation, lipid- and glucose-metabolism, as possible intermediary variables, did not appreciably alter the results. There were no significant differences in pulse wave velocity between HIV-infected and healthy children (mean difference 0.28 m/s, -0.14-0.69, p = 0.19). Conclusion HIV-infected children have an increased aortic augmentation index, compared to healthy children. Early cardiovascular assessment may be important in targeted prevention for HIV-infected children.

Multiple coronary aneurysms in a young adult with acquired immunodeficiency syndrome

HIV infection can cause multiple deleterious effects on the cardiovascular system. Emerging evidence has supported a direct association between HIV infection and accelerated atherosclerosis. The mechanism for atherosclerosis in HIV-positive patients is multifactorial, an interplay between conventional risk factors, HIV itself and highly active antiretroviral therapy. The case described is a 29-year-old man with HIV, non-adherent to antiretroviral therapy and with few cardiovascular risk factors, who presented with chest pain and non-ST elevation myocardial infarction. Cardiac catheterization revealed multiple coronary artery aneurysms in the left main coronary artery and the right coronary artery. Aneurysmal formation may develop from vasculitis, HIV itself, accelerated atherosclerosis, congenital formation or medications (e.g. protease inhibitors). The researchers provide a review of coronary artery disease, aneurysmal formation and vasculitic processes in the context of HIV. As this clinical entity becomes more apparent, alternative therapeutic options may need to be explored.

Clinical management of dyslipidaemia associated with combination antiretroviral therapy in HIV-infected patients

The introduction of potent combination antiretroviral therapy (cART) has had a remarkable impact on the natural history of HIV infection, leading to a dramatic decline in the mortality rate and a considerable increase in the life expectancy of HIV-positive people. However, cART use is frequently associated with several metabolic complications, mostly represented by lipid metabolism alterations, which are reported very frequently among persons treated with antiretroviral agents. In particular, hyperlipidaemia occurs in up to 70%-80% of HIV-positive subjects receiving cART and is mainly associated with specific antiretroviral drugs belonging to three classes of antiretroviral agents: NRTIs, NNRTIs and PIs. The potential long-term consequences of cART-associated dyslipidaemia are not completely understood, but an increased risk of premature coronary heart disease has been reported in HIV-infected patients on cART, so prompt correction of lipid metabolism abnormalities is mandatory in this population. Dietary changes, regular aerobic exercise and switching to a different antiretroviral regimen associated with a more favourable metabolic profile are the first steps in clinical management, but lipid-lowering therapy with fibrates or statins is often required. In this case, the choice of hypolipidaemic drugs should take into account the potential pharmacokinetic interactions with many antiretroviral agents.

Management of cardiovascular conditions in a cohort of patients with HIV: experience from a joint HIV/cardiology clinic

The aim of this study was to assess cardiovascular diagnoses and management in a cohort of patients diagnosed with HIV, and the performance of a joint HIV/Cardiology Clinic in a tertiary hospital setting. A retrospective analysis was performed on all patients referred to a joint HIV/Cardiology Clinic at our hospital. Data on 120 patients were collected. In this predominantly male population (male 101 and female 19) coronary artery disease (CAD) was the most common diagnosis (34%, n = 41). Other diseases included hypertension (12.5%, n = 15), cardiomyopathy (12.5%, n = 15) and arrhythmia (6%, n = 8). The majority of remaining cases included non-cardiac chest pain and palpitations. In addition to usual primary and secondary preventive measures for CAD, complex procedures, such as percutaneous coronary intervention, cardiac resynchronisation therapy for left ventricular systolic dysfunction and radiofrequency ablation for arrhythmias, were carried out. Overall cardiovascular mortality among the group was 2.5% (n = 3) over 4 years. The results indicate the efficacy of a specialist joint HIV/Cardiology Clinic in diagnosing and managing various cardiac conditions in a complex cohort of patients with HIV.

Human Immunodeficiency Virus Infection-Related Heart Disease

Human immunodeficiency virus (HIV) infection and antiretroviral medications are independent risk factors for cardiovascular disease. In the pre-antiretroviral therapy (ART) era, HIV-infected patients had increased morbidity and mortality from opportunistic infections; in the post-ART era, these patients are at increased risk of chronic diseases such as acute coronary syndrome, coronary artery disease, cardiac arrhythmias, and cardiomyopathy. They may present with vague symptoms such as weakness, dyspnea, or fatigue as the initial presentation of their cardiovascular disease. An overview of the clinical presentation, workup, management, and treatment of different cardiovascular disease is provided in this article.