Postmortem cardiomegaly and echocardiographic measurements of left ventricular size and function in children infected with the human immunodeficiency virus. The Prospective P2C2 HIV Multicenter Study

Cardiac Effects of Highly Active Antiretroviral Therapy in Perinatally HIV-Infected Children: The CHAART-2 Study

BACKGROUND

Before the introduction of highly active antiretroviral therapy (HAART), cardiac mortality and morbidity were common in HIV-infected children.

OBJECTIVES

This study sought to identify long-term cardiovascular effects of HAART in HIV-infected children.

METHODS

The CHAART-2 (HAART-Associated Cardiotoxicity in HIV-Infected Children) study prospectively compared 148 echocardiograms from 74 HAART-exposed children to 860 echocardiograms from 140 HAART-unexposed but HIV-infected children from the Pulmonary and Cardiac Complications of Vertically Transmitted HIV Infection (P²C² HIV) study. Both studies used similar protocol, centralized echocardiographic interpretation, and measures expressed as z-scores referenced to healthy controls. Associations between HAART exposure and echocardiographic measures were evaluated using generalized estimating equations.

RESULTS

Comparing the HAART-exposed and HAART-unexposed groups, any HAART exposure was positively associated with left ventricular (LV) fractional shortening (z-score for difference = 1.07; p = 0.02) and HAART exposure duration (z-score difference per year = 0.17; p = 0.003. LV mass was negatively associated with any HAART exposure (z-score difference = -0.64; p = 0.01) as was septal thickness (z-score difference = -0.93; p = 0.001). Duration of HAART exposure was negatively associated with LV end-systolic dimension and heart rate (z-score difference per year= -0.11; p = 0.05; and z-score difference per year = -0.10; p = 0.002, respectively). During 11 years of follow-up, in the HAART-exposed group, LV mass and LV end-diastolic septal thickness were lower whereas LV contractility and LV fractional shortening were higher when compared to the HAART-unexposed group.

CONCLUSIONS

Cardiac structure and function were better in perinatally HIV-infected children exposed to HAART than in those of similar children from the pre-HAART era but did decline over time. Evidence-based strategies for cardiovascular monitoring are needed to inform treatment decisions to improve long-term cardiovascular health.

Cardiac Effects of Antiretroviral-Naïve versus Antiretroviral-Exposed HIV Infection in Children

BACKGROUND

Cardiac involvement in HIV infected children has been frequently reported, but whether this is due to HIV infection itself or to antiretroviral treatment (ART) is unknown.

METHODS

This cross sectional study involved 114 vertically-acquired HIV-infected (56 ART-naive, 58 ART-exposed) and 51 healthy children in Jakarta, Indonesia. Echocardiography was performed to measure dimensions of the left ventricle (LV) and systolic functions. We applied general linear modeling to evaluate the associations between HIV infection/treatment status and cardiac parameters with further adjustment for potential confounders or explanatory variables. Findings are presented as (adjusted) mean differences between each of the two HIV groups and healthy children, with 95% confidence intervals and p values.

RESULTS

Compared to healthy children, ART-naïve HIV-infected children did not show significant differences in age-and-height adjusted cardiac dimensions apart from larger LV internal diameter (difference 2.0 mm, 95%CI 0.2 to 3.7), whereas ART exposed HIV infection showed thicker LV posterior walls (difference = 1.1 mm, 95%CI 0.5 to 1.6), larger LV internal diameter (difference = 1.7 mm, 95%CI 0.2 to 3.2) and higher LV mass (difference = 14.0 g, 7.4 to 20.5). With respect to systolic function, reduced LV ejection fraction was seen in both ART-naïve HIV infected (adjusted difference = -6.7%, -11.4 to -2.0) and, to a lesser extent, in ART-exposed HIV infected children (difference = -4.5%, -8.5 to -0.4). Inflammation level seemed to be involved in most associations in ART-exposed HIV-infected, but few, if any, for decreased function in the ART-naive ones, whereas lower hemoglobin appeared to partially mediate chamber dilation in both groups and reduced function, mainly in ART-exposed children.

CONCLUSIONS

ART-naive HIV infected children have a substantial decrease in cardiac systolic function, whereas the ART-exposed have thicker ventricular walls with larger internal diameter and higher mass, but less functional impairment.

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.

Cardiac status of children infected with human immunodeficiency virus who are receiving long-term combination antiretroviral therapy: results from the Adolescent Master Protocol of the Multicenter Pediatric HIV/AIDS Cohort Study

IMPORTANCE

Prior to contemporary antiretroviral therapies (ARTs), children infected with human immunodeficiency virus (HIV) were more likely to have heart failure. This study suggests that highly active ART (HAART) does not appear to impair heart function.

OBJECTIVE

To determine the cardiac effects of prolonged exposure to HAART on HIV-infected children.

DESIGN

In the National Institutes of Health-funded Pediatric HIV/AIDS Cohort Study's Adolescent Master Protocol (AMP), we used linear regression models to compare echocardiographic measures.

SETTING

A total of 14 US pediatric HIV clinics.

PARTICIPANTS

Perinatally HIV-infected children receiving HAART (n = 325), HIV-exposed but uninfected children (n = 189), and HIV-infected (mostly HAART-unexposed) historical pediatric controls from the National Institutes of Health-funded Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection (P2C2-HIV) Study (n = 70). EXPOSURE Long-term HAART.

MAIN OUTCOMES AND MEASURES

Echocardiographic measures of left ventricular (LV) function and structure.

RESULTS

The 325 AMP HIV-infected children had lower viral loads, higher CD4 counts, and longer durations of ART than did the 70 HIV-infected children from the P2C2-HIV Study (all P < .001). The z scores for LV fractional shortening (a measure of cardiac function) were significantly lower among HIV-infected children from the P2C2-HIV Study than among the AMP HIV-infected group or the 189 AMP HIV-exposed but uninfected controls (P < .05). For HIV-infected children, a lower nadir CD4 percentage and a higher current viral load were associated with significantly lower cardiac function (LV contractility and LV fractional shortening z scores; all P = .001) and an increased LV end-systolic dimension z score (all P < .03). In an interaction analysis by HIV-infected cohort, the HIV-infected children from the P2C2-HIV Study with a longer ART exposure or a lower nadir CD4 percentage had lower mean LV fractional shortening z scores, whereas the mean z scores were relatively constant among AMP HIV-infected children (P < .05 for all interactions).

CONCLUSIONS AND RELEVANCE

Long-term HAART appears to be cardioprotective for HIV-infected children and adolescents.

Myocardial Fas ligand expression increases susceptibility to AZT-induced cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) and myocarditis occur in many HIV-infected individuals, resulting in symptomatic heart failure in up to 5% of patients. Highly active antiretroviral therapy (HAART) has significantly reduced morbidity and mortality of acquired immunodeficiency syndrome (AIDS), but has resulted in an increase in cardiac and skeletal myopathies.

METHODS AND RESULTS

In order to investigate whether the HAART component zidovudine (3'-azido-2',3'-deoxythymidine; AZT) triggers the Fas-dependent cell-death pathway and cause cytoskeletal disruption in a murine model of DCM, 8-week-old transgenic (expressing Fas ligand in the myocardium: FasL Tg) and non-transgenic (NTg) mice received water ad libitum containing different concentrations of AZT (0, 0.07, 0.2, and 0.7 mg/ml). After 6 weeks, cardiac function was assessed by echocardiography and morphology was assessed by histopathologic and immunohistochemical methods. NTg and untreated FasL Tg mice showed little or no change in cardiac structure or function. In contrast, AZT-treated FasL Tg mice developed cardiac dilation and depressed cardiac function in a dose-dependent manner, with concomitant inflammatory infiltration of both ventricles. These changes were associated with an increased sarcolemmal expression of Fas and FasL, as well as increased activation of caspase 3, translocation of calpain 1 to the sarcolemma and sarcomere, and increased numbers of cells undergoing apoptosis. These were associated with changes in dystrophin and cardiac troponin I localization, as well as loss of sarcolemmal integrity.

CONCLUSIONS

The expression of Fas ligand in the myocardium, as identified in HIV-positive patients, might increase the susceptibility to HAART-induced cardiomyopathy due to activation of apoptotic pathways, resulting in cardiac dilation and dysfunction.

Infection of cardiomyocytes and induction of left ventricle dysfunction by neurovirulent polytropic murine retrovirus

Viral infections of the heart are a causative factor of myocarditis as well as of sudden, unexpected deaths of children, yet the mechanisms of pathogenesis remain unclear, in part due to the relatively few animal models of virus-induced myocarditis. In the current study, we examined the ability of polytropic murine retroviruses to infect the heart and induce cardiac dysfunction. In situ hybridization and immunohistochemistry analysis detected virus-infected cardiomyocytes and macrophages in the heart. A significant decrease in left ventricle function, as measured by fractional shortening, was detected in mice infected with the neurovirulent retrovirus Fr98 but not in mice infected with the nonneurovirulent retrovirus Fr54. Virus infection was not associated with consistent findings of fibrosis or substantial cellular infiltrate. Fr98-induced left ventricle dysfunction was associated with a higher virus load, increased mRNA expression of the macrophage marker F4/80, increased chemokine production, and a small number of apoptotic cells in the heart.