Cardiac manifestations of HIV/AIDS: a review of disease spectrum and clinical management

Convergent perturbation of the human domain-resolved interactome by viruses and mutations inducing similar disease phenotypes

An important goal of systems medicine is to study disease in the context of genetic and environmental perturbations to the human interactome network. For diseases with both genetic and infectious contributors, a key postulate is that similar perturbations of the human interactome by either disease mutations or pathogens can have similar disease consequences. This postulate has so far only been tested for a few viral species at the level of whole proteins. Here, we expand the scope of viral species examined, and test this postulate more rigorously at the higher resolution of protein domains. Focusing on diseases with both genetic and viral contributors, we found significant convergent perturbation of the human domain-resolved interactome by endogenous genetic mutations and exogenous viral proteins inducing similar disease phenotypes. Pan-cancer, pan-oncovirus analysis further revealed that domains of human oncoproteins either physically targeted or structurally mimicked by oncoviruses are enriched for cancer driver rather than passenger mutations, suggesting convergent targeting of cancer driver pathways by diverse oncoviruses. Our study provides a framework for high-resolution, network-based comparison of various disease factors, both genetic and environmental, in terms of their impacts on the human interactome.

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

Background:

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

Methods:

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

Results:

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

Conclusion:

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

Infectious Diseases

The objectives of this chapter are to provide a brief understanding of the following:1.

Clinical evaluation of infectious diseases and altered immune disorders, including physical examination and laboratory studies

2.

Various infectious disease processes, including etiology, pathogenesis, clinical presentation, and management

3.

Commonly encountered altered immune disorders, including etiology, clinical presentation, and management

4.

Precautions and guidelines that a physical therapist should implement when treating a patient with an infectious disease process or altered immunity

HIV Tat induces expression of ICAM-1 in HUVECs: implications for miR-221/-222 in HIV-associated cardiomyopathy

Cardiac involvement is a well-documented complication of human immunodeficiency virus-1 (HIV-1) infection. Previous studies have demonstrated increased adhesion of monocytes to human vascular endothelial cells in HIV-infected individuals. HIV Tat protein, which is the transactivator of transcription (Tat), plays a key role in activating endothelial cells. In the present study, we demonstrated that exposure of HUVECs to HIV Tat protein resulted in induced expression of cell adhesion molecules specifically ICAM-1, leading to increased adhesion of monocytes to the endothelium. This effect of Tat was mediated through activation of mitogen-activated protein kinases and downstream transcription factor NF-κB. Increased expression of ICAM-1 was regulated by microRNA (miRNA) miR-221 and to some extent by miR-222, both of which are known to target ICAM-1. Functional inhibition of the respective miRNAs with anti-miR oligonucleotides resulted in induction of ICAM-1 protein in HUVECs. Furthermore, Tat-stimulated regulation of ICAM-1 via miR-221/-222 involved the NF-kB-dependent pathway. Functional implication and specificity of up-regulated ICAM-1 was confirmed using the ICAM-1 neutralizing antibody in the in vitro cell adhesion assays. These findings were further confirmed in vivo using the HIV transgenic (Tg) rats. These animals not only demonstrated increased expression of ICAM-1 mRNA, with a concomitant reduction in the expression of miR-221 in the aorta and heart, but also had increased expression of the ICAM-1 protein that was predominantly in the endothelial cell layer. Taken together, these findings implicate that Tat-mediated induction of ICAM-1 expression plays a critical role in monocyte adhesion observed in HIV-1-associated cardiomyopathies.

Echocardiographic patterns in treatment-naïve HIV-positive patients in Lagos, south-west Nigeria

Introduction

Cardiovascular abnormalities are common in HIV-infected patients, although often clinically quiescent. This study sought to identify by echocardiography early abnormalities in treatment-naïve patients.

Methods

One hundred patients and 50 controls with no known traditional risk factors for cardiovascular disease were recruited for the study. The cases and controls were matched for age, gender and body mass index. Both groups had clinical and echocardiographic evaluation for cardiac abnormalities, and CD₄ count was measured in all patients.

Results

The cases comprised 57 females (57.0%) and 43 males (43.0%), while the controls were 28 females (56.0%) and 22 males (44.0%) (χ² = 0.01; p = 0.913). The mean age of the cases was 33.2 ± 7.7, while that of the controls was 31.7 ± 9.7 (t = 1.02; p = 0.31). Echocardiographic abnormalities were significantly more common in the cases than the controls (78 vs 16%; p = 0.000), including systolic dysfunction (30 vs 8%; p = 0.024) and diastolic dysfunction (32 vs 8%; p = 0.002). Other abnormalities noted in the cases were pericardial effusion in 47% (χ² = 32.10; p = 0.000) and dilated cardiomyopathy in 5% (five); none of the controls had either complication. One patient each had aortic root dilatation, mitral valve prolapse and isolated right heart dilatation and dysfunction.

Conclusion

Cardiac abnormalities are more common in HIV-infected people than in normal controls. A careful initial and periodic cardiac evaluation to detect early involvement of the heart in the HIV disease is recommended.

Diastolic dysfunction is associated with myocardial viral load in simian immunodeficiency virus-infected macaques

OBJECTIVE

To establish the relationship between HIV-induced cardiac diastolic dysfunction, immune responses, and virus replication in the heart using the simian immunodeficiency virus (SIV)/macaque model.

DESIGN

Cardiac diastolic dysfunction is common in HIV-infected individuals including asymptomatic patients and those treated with combination antiretroviral therapy. SIV-infected macaques develop cardiac dysfunction, serving as a useful model to establish mechanisms underlying HIV-induced cardiac dysfunction. To understand the relationship between functional cardiac impairment, viral replication in the heart, and associated host inflammatory responses, cardiac function was evaluated in SIV-infected macaques and functional decline was correlated with features of the host immune response and the extent of viral replication in both the myocardium and plasma.

METHODS

Cardiac function was evaluated longitudinally in 22 SIV-infected and eight uninfected macaques using mitral inflow and tissue Doppler echocardiography. Myocardial macrophage populations were evaluated by CD68 and CD163 immunostaining. SIV RNA levels in both myocardium and plasma were measured by qRT-PCR.

RESULTS

Echocardiographic abnormalities developed in SIV-infected macaques that closely resembled diastolic dysfunction reported in asymptomatic HIV-infected individuals. Although CD68 and CD163 were upregulated in the myocardium of SIV-infected animals, neither macrophage marker correlated with functional decline. SIV-induced diastolic dysfunction was strongly correlated with extent of SIV replication in the myocardium, implicating virus or viral proteins in the initiation and progression of cardiac dysfunction.

CONCLUSION

This study demonstrated a strong correlation between cardiac functional impairment and extent of SIV replication in the myocardium, suggesting that persistent viral replication in myocardial macrophages induces cardiomyocyte damage manifest as diastolic dysfunction.

Cardiovascular dysfunction in HIV-infected children in a sub-Saharan African country: comparative cross-sectional observational study

OBJECTIVE

Cardiac dysfunction is rarely diagnosed in HIV-infected children in our setting and standard care does not include baseline and follow-up echocardiography. We aimed to determine the prevalence, pattern and predictors of HIV-related cardiac dysfunction.

METHODS

Pre-diagnosed HIV-infected children aged 18 months to 12 years from a tertiary teaching hospital in Lagos, South-West Nigeria were enrolled in a comparative, observational cross-sectional study; matched with apparently healthy controls of the same age group, were recruited sequentially between May 2004 and 2007. Proportions of pre-defined cardiac abnormalities such as heart failure diagnosed by clinical examination and dilated cardiomyopathy and ventricular dysfunction by echocardiography were determined.

RESULTS

Prevalence of cardiac abnormalities in HIV-infected children was 75.9%. Abnormalities included heart failure, dilated cardiomyopathy (33.7%), decreased LVSF of ≤ 25% in 33.7%, increased left ventricular mass (20.5%) and pericardial effusion (14.5%).

CONCLUSION

Structural and functional abnormalities are prevalent in HIV-infected African children and therefore justify inclusion of routine echocardiography in their standard care.

Red blood cell deformability in patients with human immunodeficiency virus infection

Red blood cell (RBC) deformability is a major determinant of the ability of the RBC to pass repeatedly through the microcirculation. A decrease in RBC deformability leads to tissue perfusion and organ dysfunction. The purpose of this study was to measure the rigidity of RBCs from human immunodeficiency virus (HIV) seropositive individuals and investigate its relation to immune status and viral load. A filtration method based on the initial flow rate principle was used to determine the index of rigidity (IR) of 53 samples from HIV patients and 53 healthy individuals. The mean IR was significantly increased in patients with HIV compared to healthy individuals (P < 0.01). IR was inversely correlated with current CD4+ T-lymphocyte counts (P < 0.0001). High CD4 cell counts (>200 cells/microl) are related to low IR values, independently of the viral load (VL). No differences in rigidity were noted between the VL groups, although there was a trend towards an increased IR in patients with high VL within the group of CD4<200. RBC deformability is decreased in HIV disease, in a degree mainly related to CD4 depletion. Further studies are needed to elucidate the underlying mechanisms and the role of VL in highly immunocompromised HIV patients.

Selective expression of human immunodeficiency virus Nef in specific immune cell populations of transgenic mice is associated with distinct AIDS-like phenotypes

We previously reported that CD4C/human immunodeficiency virus (HIV)(Nef) transgenic (Tg) mice, expressing Nef in CD4(+) T cells and cells of the macrophage/dendritic cell (DC) lineage, develop a severe AIDS-like disease, characterized by depletion of CD4(+) T cells, as well as lung, heart, and kidney diseases. In order to determine the contribution of distinct populations of hematopoietic cells to the development of this AIDS-like disease, five additional Tg strains expressing Nef through restricted cell-specific regulatory elements were generated. These Tg strains express Nef in CD4(+) T cells, DCs, and macrophages (CD4E/HIV(Nef)); in CD4(+) T cells and DCs (mCD4/HIV(Nef) and CD4F/HIV(Nef)); in macrophages and DCs (CD68/HIV(Nef)); or mainly in DCs (CD11c/HIV(Nef)). None of these Tg strains developed significant lung and kidney diseases, suggesting the existence of as-yet-unidentified Nef-expressing cell subset(s) that are responsible for inducing organ disease in CD4C/HIV(Nef) Tg mice. Mice from all five strains developed persistent oral carriage of Candida albicans, suggesting an impaired immune function. Only strains expressing Nef in CD4(+) T cells showed CD4(+) T-cell depletion, activation, and apoptosis. These results demonstrate that expression of Nef in CD4(+) T cells is the primary determinant of their depletion. Therefore, the pattern of Nef expression in specific cell population(s) largely determines the nature of the resulting pathological changes.

Cardiovascular manifestations in human immunodeficiency virus-infected patients

Human immunodeficiency virus (HIV) is now a pandemic. It afflicts multiple organs, including the cardiovascular system. This occurs by direct invasion as well as opportunistic infections complicating acquired immunodeficiency syndrome. The presence of newer highly active antiretroviral therapy has led to longer survival of patients infected with HIV, but the cardiac abnormalities related to HIV have remained less well characterized. It is now evident that cardiac involvement in patients with acquired immunodeficiency syndrome is relatively common. This includes coronary artery disease, dilated cardiomyopathy, pericardial effusion, pulmonary hypertension, and ill effects of highly active antiretroviral therapy in the form of lipodystrophy, lipoatrophy, and dyslipidemia. In fact, HIV can now be viewed as a potential risk factor for coronary artery disease, and the dilemma facing clinicians is how to quantify this risk. Awareness of accelerated coronary artery disease and dilated cardiomyopathy is critical to implement preventive measures early in the course of HIV. However, better guidelines are still needed on the basis of prospective randomized controlled studies involving large populations. In conclusion, this review describes cardiac abnormalities associated with HIV, including possible molecular mechanisms. The co-morbid sequelae, their presentation, and pharmacologic management are also discussed.

Antiretroviral Drug Levels and Interactions Affect Lipid, Lipoprotein, and Glucose Metabolism in HIV-1 Seronegative Subjects: A Pharmacokinetic-Pharmacodynamic Analysis

BACKGROUND

HIV-infected patients treated with antiretroviral medications (ARVs) develop undesirable changes in lipid and glucose metabolism that mimic the metabolic syndrome and may be proatherogenic. Antiretroviral drug levels and their interactions may contribute to these metabolic alterations.

METHODS

Fifty six HIV-seronegative adults were enrolled in an open-label, randomized, pharmacokinetic interaction study, and received a nonnucleoside reverse transcriptase inhibitor (efavirenz on days 1-21) plus a protease inhibitor (PI; amprenavir on days 11-21), with a second PI on days 15-21 (saquinavir, nelfinavir, indinavir, or ritonavir). Fasting triglycerides, total LDL-and HDL-cholesterol, glucose, insulin, and C-peptide levels were measured on days 0, 14, 21, and 2-3 weeks after discontinuing drugs. Regression models were used to estimate changes in these parameters and associations between these changes and circulating levels of study drugs.

RESULTS

Short-term efavirenz and amprenavir administration significantly increased cholesterol, triglycerides, and glucose levels. Addition of a second protease inhibitor further increased triglycerides, total and LDL-cholesterol levels. Higher amprenavir levels predicted larger increases in triglycerides, total, and LDL-cholesterol. Two weeks after all study drugs were stopped, total, LDL-, and HDL-cholesterol remained elevated above baseline.

CONCLUSIONS

ARV regimens that include a nonnucleoside reverse transcriptase inhibitor plus single or boosted PIs are becoming more common, but the pharmacodynamic interactions associated with these regimens can result in persistent, undesirable alterations in serum lipid/lipoprotein levels. Additional pharmacodynamic studies are needed to examine the metabolic effects of ritonavir-boosted regimens, with and without efavirenz.

Reduced aerobic capacity and physical functioning in older HIV-infected men

Aerobic capacity and physical functioning decline with age and chronic illness. The extent of physical disability is unknown in older HIV-infected adults, who represent a rapidly growing proportion of HIV/AIDS patients in the United States. We performed functional performance testing including treadmill testing in 32 HIV-infected male veterans aged 40-69 years. Controls were 47 healthy male subjects tested previously in the same exercise laboratory. HIV-infected subjects were classified as younger (40-49 years, n = 12) or older age (50+ years, n = 20). Peak aerobic capacity (VO2peak) was significantly reduced in the older vs. younger HIV subjects [19.1 mL/kg/min +/- 5.7 (mean, SD) vs. 25.2 +/- 4.2, p = 0.01]. VO2peak was reduced 41% +/- 15% (mean, SD) in HIV-infected subjects compared to expected values from age-matched healthy controls. Regression analyses show a similar decline in VO2peak with age in HIV-infected and healthy controls. Mean 6-min walk distance was not significantly different between the HIV-infected age groups, and was reduced only 8% compared to expected values for healthy adults. Current CD4 count and HAART exposure were similar in the two age groups and were not significantly associated with VO2peak. Anemia (HCT <35%) was significantly associated with reduced VO2peak (p = 0.02), but this association was not independent of the effect of age (p = 0.1). We conclude that older HIV-infected adults have markedly impaired aerobic capacity but maintain the capacity to undertake day-to-day activities. Additional physiologic and metabolic testing is needed to measure the effect of HAART toxicity and primary aging on aerobic capacity, and to determine if older HIV-infected adults are at greater risk.

[Metabolic alterations in HIV-associated lipodystrophy syndrome]

The introduction of highly active antiretroviral therapy (HAART) has reduced morbidity and mortality in patients infected with the human immunodeficiency virus (HIV). However, prolonged treatment with combination regimens can be difficult to sustain because of problems with adherence and toxic effects. Treatment with antiretroviral agents--protease inhibitors in particular--has uncovered a syndrome of abnormal fat redistribution, impaired glucose metabolism, insulin resistance and dyslipidemia, collectively termed lipodystrophy syndrome (SLHIV). Nowadays, no clinical guidelines are available for the prevention or treatment of SLHIV, and its cause have yet to be totally elucidated. This review emphasizes the clinical features and the data from previous studies about the SLHIV taking into account that a better understanding of this syndrome for HIV specialists, cardiologists and endocrinologists is fundamental for the disease control.

A Comparison of HIV-Positive Patients with and without Infective Endocarditis: An Echocardiographic Study—The Emory Endocarditis Group Experience

OBJECTIVE

To determine the clinical features in HIV-positive patients with and without infective endocarditis (IE).

PATIENTS AND METHODS

All bacteremic, HIV-positive patients with suspected IE admitted over a four-year period who underwent either transesophageal echocardiography (TEE) or transthoracic echocardiography (TTE) were retrospectively reviewed with regard to clinical, laboratory, and demographic characteristics.

RESULTS

Ten (11.5%) of 87 HIV-positive patients had a clinical diagnosis of IE based on the Duke Criteria. The mean age of patients with IE was 37.8 years and without IE 39.9 years (P = NS). Both patient groups were similar with respect to gender, race, IVDA, renal failure requiring hemodialysis, history of predisposing heart disease, origin of infection, and causative organism of infection. The mean CD4 count (cells/microL) was 200.7 in patients with IE and 95.9 in patients without IE (P = NS). Of 10 HIV-positive patients with IE, seven had left-sided heart involvement, two had complications related to IE, three required cardiothoracic surgery, and three died.

CONCLUSIONS

There were no differences found with regard to the clinical characteristics of HIV-positive patients with and without IE. No correlation could be drawn between mortality and the degree of immunosuppression in patients from this study. The high incidence of IE (11.5%) and mortality rate (30%) in this study suggests that IE in HIV-positive patients, including non-intravenous drug abusers, represents a real concern for clinicians and their management of these patients.

Right and left ventricular cardiac function in a developed world population with human immunodeficiency virus studied with radionuclide ventriculography

BACKGROUND

Cardiac dysfunction has been reported in a substantial part of patients infected with the human immunodeficiency virus (HIV). However, most studies are from a time before the introduction of highly active antiretroviral treatment (HAART), which has significantly reduced HIV-associated morbidity and mortality rates. Accordingly, the prevalence of HIV-associated cardiac dysfunction may also have changed. The aim of the study was to establish the prevalence of right- and left-sided cardiac dysfunction in a Danish HIV population, most of whom were undergoing HAART, with radionuclide ventriculography.

METHODS

Ninety-five consecutive patients with HIV infection were included. Mean HIV duration was 104 months, and 84% of the patients received HAART. All patients underwent radionuclide ventriculography, and plasma levels of atrial natriuetic peptide (ANP), brain natriuetic peptide (BNP), and endothelin-1 (ET-1) were measured. Thirty age- and sex-matched healthy volunteer subjects were included to establish reference values of radionuclide measurements of left and right ventricular ejection fraction and of left ventricular volume.

RESULTS

Of 95 patients with HIV, 1 (1%) had a reduced left ventricular ejection fraction and 6 (7%) had a reduced right ventricle ejection fraction (0.35-0.42) compared with reference values from the age- and sex-matched reference population. Patients with HIV and reduced cardiac function did not differ in the duration of HIV, CD4 count, CD4 nadir, or HIV RNA load. No correlations were found between reduced cardiac function and levels of the 3 peptides measured.

CONCLUSIONS

No major dysfunction of the left ventricle is present in a developed world HIV population. However, a small but significant part of this population has modestly reduced right-sided systolic function.

Impaired oxygen on-kinetics in persons with human immunodeficiency virus are not due to highly active antiretroviral therapy

OBJECTIVE

To determine the effects of human immunodeficiency virus (HIV) and highly active antiretroviral therapy (HAART) on oxygen on-kinetics in HIV-positive persons.

DESIGN

Quasi-experimental cross-sectional.

SETTING

Infectious disease clinic and exercise laboratory.

PARTICIPANTS

Referred participants (N=39) included 13 HIV-positive participants taking HAART, 13 HIV-positive participants not taking HAART, and 13 noninfected controls.

INTERVENTIONS

Participants performed 1 submaximal exercise treadmill test below the ventilatory threshold, 1 above the ventilatory threshold, and 1 maximal treadmill exercise test to exhaustion.

MAIN OUTCOME MEASURES

Change in oxygen consumption (Delta.VO2) and oxidative response index (Delta.VO2/mean response time).

RESULTS

Delta.VO2 was significantly lower in both HIV-positive participants taking (946.5+/-68.1mL) and not taking (871.6+/-119.6mL) HAART than in controls (1265.3+/-99.8mL) during submaximal exercise above the ventilatory threshold. The oxidative response index was also significantly lower (P<.05) in HIV-positive participants both taking (15.0+/-1.3mL/s) and not taking (15.1+/-1.7mL/s) HAART than in controls (20.8+/-2.1mL/s) during exercise above the ventilatory threshold.

CONCLUSION

Oxygen on-kinetics during submaximal exercise above the ventilatory threshold was impaired in HIV-positive participants compared with a control group, and it appeared that the attenuated oxygen on-kinetic response was primarily caused by HIV infection rather than HAART.

[Is there an increased risk for cardiovascular disease in HIV-infected patients on antiretroviral therapy?]

There is a growing concern about an increased risk for cardiovascular disease in HIV infected patients receiving antiretroviral therapy (ART). This risk could be related to metabolic abnormalities associated with long-term use of antiretroviral drugs. In fact, well recognized cardiovascular risk factors such as hypertension, dyslipidaemia, diabetes mellitus and central fat deposition are increasingly seen in HIV patients on ART. These factors can also be associated with non reversible risk factors, such as male sex, age greater than 40 years and family history of premature coronary artery disease. In addition, cigarette smoking and sedentary lifestyle may predispose these patients to significant cardiovascular disease. A direct atherogenic effect of HIV infection itself or antiretroviral drugs is unlikely. Epidemiological studies have suggested an increased risk for coronary artery disease in HIV infected persons; nevertheless, only long term follow-up could confirm this statement. Despite these uncertainties, it seems reasonable to identify and manage cardiovascular risk factors in HIV infected patients.

Decreased peak arteriovenous oxygen difference during treadmill exercise testing in individuals infected with the human immunodeficiency virus

OBJECTIVE

To determine if arteriovenous oxygen difference was lower in asymptomatic individuals with human immunodeficiency virus (HIV) infection than in sedentary but otherwise healthy controls.

DESIGN

Quasi-experimental cross-sectional.

SETTING

Clinical exercise laboratory.

PARTICIPANTS

Fifteen subjects (10 men, 5 women) with HIV and 15 healthy gender- and activity level-matched controls (total N=30).

INTERVENTION

Participants performed an incremental maximal exercise treadmill test to exhaustion. Electrocardiogram, metabolic, and noninvasive cardiac output measurements were evaluated at rest and throughout the tests. Data were analyzed by using analysis of covariance.

MAIN OUTCOME MEASURES

Peak oxygen consumption (Vo(2)), cardiac output, stroke volume, and arteriovenous oxygen difference. The arteriovenous oxygen difference was determined indirectly using the Fick equation.

RESULTS

Peak VO(2) was significantly lower (P<.0005) in participants with HIV (24.6+/-1.2mL.kg(-1).min(-1)) compared with controls (32.0+/-1.2mL.kg(-1).min(-1)). There were no significant intergroup differences in cardiac output or stroke volume at peak exercise. Peak arteriovenous oxygen difference was significantly lower (P<.04) in those infected with HIV (10.8+/-0.5 volume %) than in controls (12.4+/-0.5 volume %).

CONCLUSION

The observed deficit in aerobic capacity in the participants with HIV appeared to be the result of a peripheral tissue oxygen extraction or utilization limitation. In addition to deconditioning, potential mechanisms for this significant attenuation may include HIV infection and inflammation, highly active antiretroviral therapy medication regimens, or a combination of these factors.

Cardiovascular complications in patients with HIV infection

As advances in early diagnosis and aggressive therapy, as well as better supportive care, become available to a larger number of patients with HIV infection, survival is being prolonged, and more patients are experiencing cardiac abnormalities. The most common cardiac manifestations of HIV disease are dilated cardiomyopathy, myocarditis, pericardial effusion, endocarditis, pulmonary hypertension, HIV-associated malignant neoplasms, and drug-related cardiotoxicity. The introduction of highly active antiretroviral therapy (HAART) regimens has substantially modified the course of HIV disease by lengthening survival and improving quality of life of HIV-infected patients. However, early data have raised concerns about HAART being associated with an increase in peripheral and coronary arterial disease. This review discusses the principal HIV-associated cardiovascular manifestations and emphasizes new knowledge about their prevalence, pathogenesis, and treatment.

Infective endocarditis and cardiac surgery in intravenous drug abusers and HIV-1 infected patients

Infective endocarditis (IE) is one of the most severe complications of parenteral drug abuse. The incidence of IE in intravenous drug abusers (IVDAs) is 2% to 5% per year, being responsible for 5% to 10% of the overall death rate. The prevalence of HIV infection among IVDAs with IE ranges between 30% and 70% in developed countries and HIV-infection by itself increases the risk of IE in IVDAs. The incidence of IE in IVDAs is currently decreasing in some areas, probably due to changes in drug administration habits by addicts to avoid HIV transmission. Overall, Staphylococcus aureus is the most common etiological agent, being usually sensitive to methicillin (MSSA). The tricuspid valve is the most frequently affected (60% to 70%), followed by the mitral and aortic valves (20% to 30%). HIV-positive IVDAs have a higher ratio of right-sided IE and S aureus IE than HIV-negative IVDAs. Response to antibiotic therapy is similar. Drug addicts with non-complicated MSSA right-sided IE can be treated with an i.v. short-course regimen of nafcillin or cloxacillin for 2 weeks, with or without addition of an aminoglycoside during the first 3 to 7 days. The prognosis of right-sided endocarditis is generally good; overall mortality is less than 5%, and with surgery is less than 2%. In contrast, the prognosis of left-sided IE is less favorable; mortality is 20% to 30%, and even with surgery is 15% to 25%. IE caused by GNB or fungi has the worst prognosis. Mortality between HIV-infected or non-HIV-infected IVDAs with IE is similar. However, among HIV-infected IVDAs, mortality is significantly higher in those who are most severely immunosuppressed, with CD4+ cell count < 200/microL or with AIDS criteria. Conversely, IE in HIV-infected patients who are not drug abusers is rare. The epidemiology of cardiac surgery in IVDAs and/or HIV-infected patients has changed in recent years. There is a decrease in IE and an increase of patients undergoing surgery (CABS) for coronary artery disease secondary to the hyperlipidemia and lipodystrophy induced by highly active antiretroviral therapy (HAART). Cardiac surgery in HIV-infected patients with or without IE does not worsen the prognosis because extracorporeal circulation did not affect the immune status after surgery. Morbidity and mortality seems to stay within the same range as the non-infected patients. In our experience, in the IE in HIV-infected IVDA group, the 1-year survival is 65% and the 5 and 10-year actuarial survival is 35%. For patients operated on for coronary artery disease, the 5-year survival is 100%.

Epidemiology of HIV cardiac disease

The heart is an organ frequently affected in patients with acquired immune deficiency syndrome (AIDS). Since the introduction of highly active antiretroviral therapy (HAART), a sharp decline in mortality and morbidity has been observed in human immunodeficiency virus (HIV)-infected patients. However, numerous reports of myocardial infarcts in young HIV-infected patients have raised concerns of premature coronary artery disease in this population. New risk factors for coronary heart disease such as increased insulin resistance, dyslipidemia, and lipodystrophy syndrome, which are associated with HAART, may accelerate underlying arteriosclerosis in HIV-infected patients. Data on the incidence of coronary heart disease are limited to case reports and retrospective studies. Results from ongoing, large, prospective studies will provide information on whether or not HAART may increase the incidence of myocardial infarcts and whether a drastic change in HIV therapy is warranted.

Infective endocarditis not related to intravenous drug abuse in HIV-1-infected patients: report of eight cases and review of the literature

OBJECTIVES

To add to the limited information on infective endocarditis (IE) not related to intravenous drug abuse (IVDA) in HIV-1-infected patients.

METHODS

We have reviewed the characteristics of eight cases of IE in non-IVDA HIV-1 infected patients diagnosed in our institution between 1979 and 1999 as well as cases in the literature.

RESULTS

All our patients were male, and the mean age was 44 years (range 29-64). HIV-1 risk factors were: homosexuality in five, heterosexuality in two, and the use of blood products in one. HIV stage C was found in six cases, and the median (range) CD4 cell count was 22/microL (4-274 cells/microL). IE was caused by Enterococcus faecalis in three cases, staphylococci in two cases, and Salmonella enteritidis, viridans group streptococci and Coxiella burnetii in one case each. Three patients acquired IE while in the hospital. All IE cases involved a native valve, and underlying valve disease was found in three patients. The aortic valve was the most frequently affected (five cases). Two patients underwent surgery, with a good outcome, and one patient died. Fourteen cases of IE not related to IVDA in HIV-1-infected patients were found in the literature review. The most common causative agents were Salmonella spp. and fungi (four cases each). Two patients had prosthetic valve IE, and the mitral valve was the most frequently affected (10 cases). The remaining clinical characteristics and the outcome were similar to those in the present series.

CONCLUSIONS

IE not related to IVDA is rare in HIV-1-infected patients. In more than half of the cases, IE develops in patients with advanced HIV-1 disease. A wide etiologic range is found, reflecting different clinical and environmental conditions. None of the patients who underwent surgery died, and the overall mortality rate was not higher than in non-HIV-1-infected patients with IE.

Myocardial and Pericardial Disease in HIV

Cardiovascular complications are frequently encountered in the HIV-infected population. Cardiac care providers should implement appropriate preventive, screening, and therapeutic strategies to maximize survival and quality of life in this increasingly treatable, chronic disease. All HIV-infected individuals should undergo periodic cardiac evaluation, including echocardiography, in order to identify subclinical cardiac dysfunction. Left ventricular (LV) dysfunction can result from, or be exacerbated by, a variety of treatable infectious, endocrine, nutritional, and immunologic disorders. Aggressive diagnosis and treatment of these conditions may lead to improvement or even normalization of myocardial function. Endomyocardial biopsy should be considered to direct etiology-specific therapy. Standard measures for the prevention and treatment of congestive heart failure are recommended for HIV-infected patients. Afterload reduction with angiotensin-converting enzyme inhibitors may be indicated for patients with elevated afterload and preclinical LV dysfunction diagnosed by echocardiogram. However, judicious drug selection and titration are necessary in this cohort of patients with frequent autonomic dysfunction, at risk for a number of potentially lethal drug interactions. Carnitine, selenium, and multivitamin supplementation should be considered, especially in those with wasting or diarrhea syndromes. Monthly intravenous immunoglobulin (IVIG) infusions have been demonstrated to preserve LV parameters in HIV-infected children; ventricular recovery has been documented in some children with recalcitrant HIV-related cardiomyopathy following IVIG infusion. We support the use of immunomodulatory therapy in the pediatric population, and look forward to further study into the efficacy and broader application of this approach. Highly active antiretroviral therapy (HAART) may be associated with dyslipidemia and the metabolic syndrome. This should be treated with dietary and possibly with pharmacologic interventions. Drug interactions need to be considered when instituting pharmacologic therapies. Pericardial effusions are often seen in patients with advanced HIV infection. Asymptomatic effusions are most often nonspecific in nature, related to the proinflammatory milieu found in advanced AIDS. Nonspecific effusions are a marker of advanced disease and do not require exhaustive etiologic evaluation. In contrast, large or symptomatic effusions are often associated with infection or malignancy, and warrant thorough investigation and etiology-specific treatment.

Plasma levels of brain natriuretic peptide: a potential marker for HIV-related cardiomyopathy

One of the most common and life-threatening cardiovascular complications of HIV-infection is severe global left ventricular dysfunction due to primary heart muscle disease. At present, there is no single, cost-effective and reliable method of identifying the highly prevalent HIV-related cardiac dysfunction. Nonetheless, growing evidence supports the hypothesis that brain natriuretic peptide measurement has the potential to detect patients who develop HIV-related cardiomyopathy. If true, this hypothesis would have important clinical and public health implications.

Infective endocarditis in intravenous drug abusers and HIV-1 infected patients

Infective endocarditis (IE) is one of the most severe complications of parenteral drug abuse. The incidence of IE in intravenous drug abusers (IVDAs) is 2% to 5% per year, being responsible for 5% to 20% of hospital admissions and 5% to 10% of the overall death rate. IVDAs often develop recurrent IE. The prevalence of HIV infection among IVDAs with IE ranges between 30% and 70% in urban areas in developed countries. The incidence of IE in IVDAs is currently decreasing in some geographical areas, probably due to changes in drug administration habits undertaken by addicts in order to avoid HIV transmission. Overall, Staphylococcus aureus is the most common etiological agent, being in most geographical areas sensitive to methicillin (MSSA). The remainder of cases is caused by streptocococci, enterococci, GNR, Candida spp, and other less common organisms. Polymicrobial infection occurs in 2% to 5% of cases. The tricuspid valve is the most frequently affected (60% to 70%), followed by the mitral and aortic valves (20% to 30%); pulmonic valve infection is rare (< 1%). More than one valve is infected in 5% to 10% of cases. HIV-positive IVDAs have a higher ratio of right-sided IE and S. aureus IE than HIV-negative IVDAs. Response to antibiotic therapy is similar among HIV-infected or non-HIV-infected IVDAs. Drug addicts with non-complicated MSSA right-sided IE can be treated successfully with an i.v. short-course regimen of nafcillin or cloxacillin for 2 weeks, with or without addition of an aminoglycoside during the first 3 to 7 days. Surgery in HIV-infected IVDAs with IE does not worsen the prognosis. The prognosis of right-sided endocarditis is generally good; overall mortality is less than 5%, and with surgery less than 2%. In contrast, the prognosis of left-sided IE is less favorable; mortality is 20% to 30%, and even with surgery is 15% to 25%. IE caused by GNB or fungi has the worst prognosis. Mortality between HIV-infected or non-HIV-infected IVDAs with IE is similar. However, among HIV-infected IVDAs, mortality is significantly higher in those who are most severely immunosuppressed, with CD4+ cell count < 200/microL or with AIDS criteria. Finally, IE in HIV-infected patients who are not drug abusers is rare.

Cardiology and AIDS--HAART and the consequences

Since the introduction of highly active antiretroviral therapy (HAART), AIDS has become a treatable disease. A steep decline in morbidity and mortality has been observed in most western countries. The HIV epidemic is now moving into middle-aged populations which are already at increased risk for cardiovascular disease. Since the cardiovascular system is frequently affected in HIV infection, reflections on traditional cardiovascular risk factors is a pressing issue. Moreover, during the last few years, complex lipodystrophic body changes in association with metabolic abnormalities such as dyslipidemia and insulin resistance have become a common feature in HIV+ patients on HAART. Although the precise mechanisms are not fully understood, early reports on myocardial infarctions and vascular changes have raised concern about the possibility of an epidemic of cardiovascular events among HAART patients within the next decade. Not only more data on lipid-lowering drugs in the context of HAART, on switching strategies, and treatment interruptions, but also from intervention studies on traditional risk factors such as smoking, are urgently needed. In this review the key issues concerning cardiovascular aspects of HIV infection in the era of HAART and possible preventive strategies are discussed.

Drugs and cardiotoxicity in HIV and AIDS

The advent of potent antiretroviral drugs in recent years has had an impressive impact on mortality and disease progression in HIV-infected patients, so that issues related to long-term effects of drugs are of growing importance. Hyperlipidemia, hyperglycemia, and lipodystrophy are increasingly described adverse effects of highly active antiretroviral therapy (HAART), in particular when protease inhibitors are used. Hyperlipidemia is strikingly associated with the use of most available protease inhibitors, with an estimated prevalence of up to 50%. Because of the short observation period and the small number of cardiovascular events, epidemiological evidence for an increased risk of coronary heart disease in HIV-infected patients treated with HAART is not adequate at present; however, it is likely that shortly more data will accumulate to quantify this risk. Before starting HAART and during treatment it is reasonable to evaluate all patients for traditional coronary risk factors, including lipid profile. Among the drugs that are currently used in HIV+ patients, antibacterials, antifungals, psychotropic drugs and anti-histamines have been associated with QT prolongation or torsade de pointe, a life-threatening ventricular arrhythmia. Among the risk factors that may precipitate an asymptomatic electrocardiographic abnormality into a dangerous arrhythmia is the concomitant use of drugs that share the CYP3A metabolic pathway. Since most protease inhibitors are potent inhibitors of CYP3A, clinicians should be aware of this potentially dangerous effect of HAART. Anthracyclines are potent cytotoxic antibiotics that have been widely used for the treatment of HIV-related neoplasms. Their cardiotoxicity is well known, ranging from benign and reversible arrhythmias to progressive severe cardiomyopathy. The increased survival and quality of life of HIV+ patients emphasize the importance of a high awareness of adverse drug-related cardiac effects.

Coronary heart disease associated with the use of human immunodeficiency virus (HIV)-1 protease inhibitors: report of four cases and review

Four cases of human immunodeficiency virus (HIV)-infected patients who developed coronary heart disease (CHD) while under treatment with a protease inhibitor (PI) are described, and the epidemiologic and clinical features of 18 cases reported in the literature are analyzed. Cardiac manifestations mostly included myocardial infarctions. Smoking and hyperlipidemia were the most common risk factors for CHD, reported in 72 and 81% of the patients, respectively. Hypercholesterolemia was observed in 75% of the cases at the time of the cardiovascular event. Ninety percent of the patients with pretreatment normal lipid values experienced a rise in the plasma lipid levels during PI therapy. Although a definite relationship between the development of CHD and HIV PIs can not be made, this analysis suggests that PI-induced hyperlipidemia may play a role in accelerating coronary atherosclerosis in patients with concomitant risk factors. Evaluation and control of risk factors for CHD should be performed in each patient for whom treatment with a PI is indicated.

Pathogenesis of HIV-associated cardiovascular complications

Reviews and studies published before the introduction of highly active antiretroviral therapy (HAART) have tracked the incidence and course of HIV infection in relation to cardiac illness in both children and adults. The introduction of HAART regimens has significantly modified the course of HIV disease, with longer survival rates and improvement of life quality in HIV-infected people expected. However, early data raised concerns about HAART being associated with an increase in both peripheral and coronary arterial diseases. In this review we discuss HIV-associated cardiovascular complications focusing on pathogenetic mechanisms that could have a role in diagnosis, management, and therapy of these complications in the HAART era.

Mitochondrial toxicity and HIV therapy

Nucleoside reverse transcriptase inhibitors (NRTIs) remain the cornerstone of highly active antiretroviral therapy (HAART) combination regimens. However, it has been known for some time that these agents have the potential to cause varied side effects, many of which are thought to be due to their effects on mitochondria. Mitochondria, the key energy generating organelles in the cell, are unique in having their own DNA, a double stranded circular genome of about 16 000 bases. There is a separate enzyme present inside the cell that replicates mitochondrial DNA, polymerase gamma. NRTIs can affect the function of this enzyme and this may lead to depletion of mitochondrial DNA or qualitative changes. The study of inherited mitochondrial diseases has led to further understanding of the consequences of mutations or depletion in mitochondrial DNA. Key among these is the realisation that there may be substantial heteroplasmy among mitochondria within a given cell, and among cells in a particular tissue. The unpredictable nature of mitochondrial segregation during cellular replication makes it difficult to predict the likelihood of dysfunction in a given tissue. In addition, there is a threshold effect for the expression of mitochondrial dysfunction, both at the mitochondrial and cellular level. Various clinical and in vitro studies have suggested that NRTIs are associated with mitochondrial dysfunction in different tissues, although the weight of evidence is limited in many cases. The heterogeneity in the tissues affected by the different drugs raises interesting questions, and possible explanations include differential distribution or activation of these agents. This article reviews the major recognised toxicities associated with NRTI therapy and evidence for mitochondrial dysfunction in these complications. Data were identified through searching of online databases including Medline and Current Contents for relevant articles, along with abstracts and posters from recent conferences in the HIV and mitochondrial fields.

EMERGENCY DEPARTMENT EVALUATION OF THE CHEST PAIN PATIENT

The emergency physician must have a high degree of suspicion for myocardial ischemia in patients presenting with no obvious for their chest pain. The role of the emergency physician is to determine a relative risk for each patient and to order the appropriate studies to minimize the risk of missed myocardial infarction as well as to recognize acute ischemia or infarction and manage it aggressively. It is not possible to rule out myocardial ischemia or infarction subjectively. It is the opinion of these authors that some form of further testing should be performed on patients in all categories, except those determined to be at very low risk.

The effects of HIV infection on endothelial function

Endothelial dysfunction and/or injury is pivotal to the development of cardiovascular and inflammatory pathology. Endothelial dysfunction and/or injury has been described in Human Immunodeficiency Virus (HIV) infection. Elaboration of circulating markers of endothelial activation, such as soluble adhesion molecules and procoagulant proteins, occurs in HIV infection. Certain endothelial cells, such as those lining liver sinusoids, human umbilical vein endothelial cells, bone marrow stromal endothelial cells or brain microvascular endothelial cells, have been shown to be variably permissive for HIV infection. Entry of virus into endothelial cells may occur via CD4 antigen or galactosyl-ceramide receptors. Other mechanisms of entry including chemokine receptors have been proposed. Nevertheless, endothelial activation may also occur in HIV infection either by cytokines secreted in response to mononuclear or adventitial cell activation by virus or else by the effects of the secreted HIV-associated proteins, gp 120 (envelope glycoprotein) and Tat (transactivator of viral replication) on endothelium. Enhanced adhesiveness of endothelial cells, endothelial cell proliferation and apoptosis as well as activation of cytokine secretion have all been demonstrated. Synergy between select inflammatory cytokines and viral proteins in inducing endothelial injury has been shown. In HIV infection, dysfunctional or injured endothelial cells potentiate tissue injury, inflammation and remodeling, and accelerate the development of cardiovascular disease.

Secondary and Infiltrative Cardiomyopathies

Secondary and infiltrative cardiomyopathies are the least common forms of cardiomyopathy and often are the most difficult to treat. In all cases, efforts should be made to establish a specific diagnosis because the removal or avoidance of the causative agent (eg, alcohol, cocaine, persistent tachycardia) holds the best promise for reversal of ventricular dysfunction. Patients who present with a dilated cardiomyopathy (DCM) should be treated with standard heart failure therapy. However, the "standard" is changing and clinicians need to take heed of results of recent trials establishing the role of beta-blockers, aldosterone, and angiotensin receptor antagonists in addition to the regimen of digoxin, diuretics and angiotensin-converting enzyme (ACE) inhibitors. In contrast, patients who present with a more infiltrative clinical picture often manifest more diastolic dysfunction and need strict volume control to maintain euvolemia. For patients with biopsy-proven myocarditis, immunosuppressive therapy generally should be considered in an effort to maintain and potentially improve ventricular function. Patients with sarcoid heart disease have shown the greatest response to high-dose corticosteroids. Patients with hemochromatosis related cardiomyopathy should be treated with iron chelation therapy and phlebotomy. The role of cardiac transplantation is limited, as most of the secondary and infiltrative causes of cardiomyopathy are associated with an adverse posttransplant outcome. Other surgical options, such as left ventricular assist devices, may offer hope to patients who would otherwise be ineligible for cardiac transplantation. On the horizon, biventricular pacing and treatments targeted at cytokines and hormonal receptors hold the promise of improving symptoms and prolonging survival by counteracting the deleterious effects of these secondary mediators.

Coronary artery disease and human immunodeficiency virus infection

Recent reports of myocardial infarctions in young persons infected with human immunodeficiency virus (HIV) who are receiving protease inhibitor therapy have raised concerns about premature coronary artery disease in this population. Endothelial dysfunction, hypercoagulability, hypertriglyceridemia, and abnormal coronary artery pathology were in fact associated with HIV infection prior to the availability of protease inhibitor therapy. Newly recognized risk factors, such as insulin resistance, hypercholesterolemia, and fat redistribution syndrome, may exacerbate underlying atherosclerotic risk for patients receiving protease inhibitors. Data on the incidence of myocardial infarction among these patients are largely limited to case reports but are of concern. Pending the availability of further data, it is prudent to monitor these patients for hyperlipidemia and consider interventions to modify cardiac risk factors.

Syringe laws and pharmacy regulations are structural constraints on HIV prevention in the US

OBJECTIVE

To review the legal and regulatory barriers that restrict pharmacy sales of syringes to injection drug users (IDUs) and to discuss how reducing these barriers can facilitate access to sterile syringes for IDUs and improve HIV prevention.

BACKGROUND

IDUs' access to sterile syringes from community pharmacies in the United States is limited by state laws and regulations governing syringe sales. Restricted availability of sterile syringes from pharmacies is a structural barrier that greatly impedes HIV prevention for IDUs, who often share and reuse syringes because they cannot obtain and possess sterile syringes. These high-risk behaviors contribute to the transmission of HIV and other blood-borne pathogens among IDUs, their sexual partners, and their children. STATE EXPERIENCES: In Connecticut, because of high HIV prevalence among IDUs, restrictive syringe laws were changed. After the legal changes in Connecticut, both pharmacy sales of syringes in areas of high drug use and purchases of syringes in pharmacies (reported by IDUs) increased, while syringe sharing (reported by IDUs) decreased. Maine and Minnesota have made similar changes in laws.

CONCLUSIONS

Increasing access to sterile syringes through pharmacies requires the repeal or modification of legal barriers. Pharmacy sale of syringes to IDUs is an inexpensive HIV prevention intervention with the potential to substantially reduce HIV transmission. Further studies are needed to document how changes to legal barriers can influence HIV prevention for IDUs.

Impact of highly active antiretroviral therapy in HIV-positive patients with cardiac involvement

OBJECTIVES

Cardiac involvement is frequently observed in HIV-infected patients, especially in those in the late stage of the disease. This study was designed to evaluate the impact of highly active antiretroviral therapy (HAART) in patients with cardiac involvement.

METHODS

A retrospective study of 1042 patients admitted to a Division of Infectious Diseases between 1989 and 1998. During the period 1989-1995, 544 patients were treated with nucleoside reverse transcriptase inhibitors (NRTI), whereas 498 patients were treated with HAART during the period 1996-1998.

RESULTS

Cardiac involvement, including arrhythmias, pericarditis, ischaemia, dilated cardiomyopathy, endocarditis, pulmonary hypertension, and myocarditis were observed in 282 of 544 (51.8%) patients treated with NRTI, compared with 93 of 498 (18.6%) patients with HAART (P < 0.0001).

CONCLUSIONS

HAART has significantly decreased the incidence of cardiac involvement, especially pericarditis, arrhythmias, and dilated cardiomyopathy.

Medical management of HIV disease in children

Significant advances have been made in the understanding of the pathophysiology of HIV infection since the beginning of the epidemic. This knowledge has translated into the development of new therapies for HIV and opportunistic infections, laboratory advances in monitoring viral and immune status, and a better understanding of factors affecting patient outcome. Concomitantly, significant progress has been made in the medical management of children with HIV infection in the past 5 years. The number of children reported with AIDS in the United States is decreasing, and efforts are shifting from caring for children with advanced immunosuppression and severe opportunistic infections to early HAART, maintenance of the immune system, and prevention of opportunistic infections. Primary care physicians are now more involved and informed in the care of HIV-infected patients. Although published data are limited, physicians who have been working with this population have observed a dramatic improvement in the quality of life and length of survival of these patients. Unfortunately, this progress is not shared by developing countries where resources are minimal and antiretroviral agents are commonly unavailable. Although efforts to develop a vaccine to prevent HIV infection are ongoing, progress has been slow. Education and awareness continue to be the most powerful weapons against HIV.