HIV and Global Cardiovascular Health

MRI Assessment of Diastolic Dysfunction in People Living With the Human Immunodeficiency Virus: Correlation With Markers of Disease Activity

BACKGROUND

Despite the advent of combination antiretroviral therapy, people living with human immunodeficiency virus (PLWH) are at an increased risk for cardiac disease.

PURPOSE

To explore the presence and extent of diastolic atrial and left ventricular dysfunction in PLWH using cardiac MRI in correlation with clinical markers of disease activity.

STUDY TYPE

Prospective.

POPULATION

A total of 163 participants comprising 101 HIV-infected individuals (age: 52 years [42-62 years]; 92% male) and 62 age- and sex-matched healthy volunteers (age: 51 years [30-72 years]; 85% male).

FIELD STRENGTH/SEQUENCE

3.0 T, cardiac MRI including balanced steady-state free precession (SSFP) for the short-axis, two-, three-, and four-chamber views were performed.

ASSESSMENT

Assessment of cardiac function and strain analysis were accomplished by CVI42 software. Blood samples for CD4+ T cells and cardiac risk factors were also collected before MRI.

STATISTICAL TESTS

Independent t tests, Mann-Whitney U test, Pearson's correlation analysis, and multivariate linear analyses (significance level: P < 0.05).

RESULTS

PLWH had a significantly larger left atrial volume maximum index (LAVImax: 32.6 ± 8.7 vs. 28.7 ± 8.1 mL/m2), minimum (LAVImin: 14.8 ± 5.5 vs. 11.5 ± 5.4 mL/m2,), and prior to atrial contraction (LAVIpre-a: 23.4 ± 6.7 vs. 19.7 ± 7.2 mL/m2) as compared to healthy volunteers. The LA reservoir (LAtEF: 55.0 ± 10.2 vs. 61.4 ± 10.4; Sls: 29.0 ± 8.1 vs. 33.8 ± 11.8), conduit (LApEF: 28.4 ± 8.2 vs. 32.3 ± 11.3, P = 0.01; Sle: 16.3 ± 6.5 vs. 18.9 ± 8.2), and booster pump function (LAaEF: 37.4 ± 12.4 vs. 42.7 ± 13.1, P = 0.01, Sla: 12.7 ± 5.1 vs. 14.9 ± 5.7) were all significant impaired in PLWH. Global circumferential left ventricular diastolic strain rate (LVGCS-d) was significantly lower in the HIV patients. Multivariate analysis results showed that Nadir CD4+ T cells had a significant adverse association with LVGCS-d (β = 0.51).

CONCLUSION

LA structure abnormalities and LV diastolic dysfunction were manifested in PLWH, with Nadir CD4+ T cell counts potentially serving as a risk factor for early cardiac diastolic dysfunction.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 3.

HIV Infection, Antiretroviral Drugs, and the Vascular Endothelium

Endothelial cell activation, injury, and dysfunction underlies the pathophysiology of vascular diseases and infections associated with vascular dysfunction, including human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome. Despite viral suppression with combination antiretroviral therapy (ART), people living with HIV (PLWH) are prone to many comorbidities, including neurological and neuropsychiatric complications, cardiovascular and metabolic diseases, premature aging, and malignancies. HIV and viral proteins can directly contribute to the development of these comorbidities. However, with the continued high prevalence of these comorbidities despite viral suppression, it is likely that ART or some antiretroviral (ARVs) drugs contribute to the development and persistence of comorbid diseases in PLWH. These comorbid diseases often involve vascular activation, injury, and dysfunction. The purpose of this manuscript is to review the current literature on ARVs and the vascular endothelium in PLWH, animal models, and in vitro studies. I also summarize evidence of an association or lack thereof between ARV drugs or drug classes and the protection or injury/dysfunction of the vascular endothelium and vascular diseases.

Alterations in Th17 Cells and Non-Classical Monocytes as a Signature of Subclinical Coronary Artery Atherosclerosis during ART-Treated HIV-1 Infection

Cardiovascular disease (CVD) remains an important comorbidity in people living with HIV-1 (PLWH) receiving antiretroviral therapy (ART). Our previous studies performed in the Canadian HIV/Aging Cohort Study (CHACS) (>40 years-old; Framingham Risk Score (FRS) > 5%) revealed a 2-3-fold increase in non-calcified coronary artery atherosclerosis (CAA) plaque burden, measured by computed tomography angiography scan (CTAScan) as the total (TPV) and low attenuated plaque volume (LAPV), in ART-treated PLWH (HIV+) versus uninfected controls (HIV-). In an effort to identify novel correlates of subclinical CAA, markers of intestinal damage (sCD14, LBP, FABP2); cell trafficking/inflammation (CCL20, CX3CL1, MIF, CCL25); subsets of Th17-polarized and regulatory (Tregs) CD4+ T-cells, classical/intermediate/non-classical monocytes, and myeloid/plasmacytoid dendritic cells were studied in relationship with HIV and TPV/LAPV status. The TPV detection/values coincided with higher plasma sCD14, FABP2, CCL20, MIF, CX3CL1, and triglyceride levels; lower Th17/Treg ratios; and classical monocyte expansion. Among HIV+, TPV+ versus TPV- exhibited lower Th17 frequencies, reduced Th17/Treg ratios, higher frequencies of non-classical CCR9lowHLADRhigh monocytes, and increased plasma fibrinogen levels. Finally, Th17/Treg ratios and non-classical CCR9lowHLADRhigh monocyte frequencies remained associated with TPV/LAPV after adjusting for FRS and HIV/ART duration in a logistic regression model. These findings point to Th17 paucity and non-classical monocyte abundance as novel immunological correlates of subclinical CAA that may fuel the CVD risk in ART-treated PLWH.

A Blood Immunological Signature of Subclinical Coronary Artery Atherosclerosis in People Living with HIV-1 Receiving Antiretroviral Therapy

Cardiovascular disease (CVD) remains an important co-morbidity in people living with HIV-1 (PLWH) receiving antiretroviral therapy (ART). Our previous studies performed on the Canadian HIV/Aging Cohort Study (CHACS) (>40 years-old; Framingham Risk Score (FRS) >5%), revealed a 2-3-fold increase in non-calcified coronary artery atherosclerosis (CAA) plaque burden, measured by Computed tomography angiography scan (CTAScan) as total (TPV) and low attenuated plaque volume (LAPV) in ART-treated PLWH (HIV+) versus uninfected controls (HIV-). In an effort to identify novel correlates of subclinical CAA, markers of intestinal damage (sCD14, LBP, FABP2); cell trafficking/inflammation (CCL20, CX3CL1, MIF, CCL25); subsets of Th17-polarized and regulatory (Tregs) CD4 + T-cells, classical/intermediate/non-classical monocytes, and myeloid/plasmacytoid dendritic cells, were studied in relationship with HIV and TPV/LAPV status. The TPV detection/values coincided with higher plasma sCD14, FABP2, CCL20, MIF, CX3CL1 and triglyceride levels, lower Th17/Treg ratios, and classical monocyte expansion. Among HIV + , TPV + versus TPV - exhibited lower Th17 frequencies, reduced Th17/Treg ratios, higher frequencies of non-classical CCR9 low HLADR high monocyte, and increased plasma fibrinogen levels. Finally, Th17/Treg ratios and non-classical CCR9 low HLADR high monocyte frequencies remained associated with TPV/LAPV after adjusting for FRS and HIV/ART duration in a logistic regression model. These findings point to Th17 paucity and non-classical monocyte abundance as novel immunological correlates of subclinical CAA that may fuel the CVD risk in ART-treated PLWH.

Coronary artery endothelial function and aging in people with HIV and HIV-negative individuals

Coronary artery disease (CAD) is a common comorbidity in people with human immunodeficiency virus (HIV) (PWH) and impaired coronary endothelial function (CEF) plays a central role in the pathogenesis of CAD. Age-related impaired CEF among PWH, however, is not well characterized. We investigated the association between CEF and age in males and females with and without HIV using 3-T magnetic resonance imaging (MRI). We measured the changes in coronary cross-sectional area (CSA) and coronary blood flow during isometric handgrip exercise (IHE), an established endothelial-dependent stressor with smaller increases in CSA and coronary blood flow indicative of impaired CEF. We included 106 PWH and 82 individuals without HIV. Differences in demographic and clinical characteristics between PWH and individuals without HIV were explored using Pearson's χ2 test for categorical variables and Welch's t test for continuous variables. Linear regression models were used to examine the association between CEF and age. CEF was significantly lower in PWH as compared with individuals without HIV. Coronary endothelial dysfunction was also present at younger ages in PWH than in the individuals without HIV and there were significant differences in CEF between the PWH and individuals without HIV across age groups. Among the individuals without HIV, the percent changes in CSA were inversely related to age in unadjusted and adjusted models. There was no significant association between CEF and age in PWH. To the best of our knowledge, this is the first study to examine the relationship between age and CEF in PWH, and our results suggest that factors other than age significantly impair CEF in PWH across the life span.NEW & NOTEWORTHY This is the first study to examine the relationship between age and coronary endothelial function (CEF) in people with human immunodeficiency virus (HIV) (PWH). CEF was assessed using magnetic resonance imaging (MRI) in people with and without HIV. Although age and CEF were significantly inversely related in individuals without HIV, there was no association between age and CEF in PWH.

Identification of aryl hydrocarbon receptor as a barrier to HIV-1 infection and outgrowth in CD4+ T cells

The aryl hydrocarbon receptor (AhR) regulates Th17-polarized CD4+ T cell functions, but its role in HIV-1 replication/outgrowth remains unknown. Genetic (CRISPR-Cas9) and pharmacological inhibition reveal AhR as a barrier to HIV-1 replication in T cell receptor (TCR)-activated CD4+ T cells in vitro. In single-round vesicular stomatitis virus (VSV)-G-pseudotyped HIV-1 infection, AhR blockade increases the efficacy of early/late reverse transcription and subsequently facilitated integration/translation. Moreover, AhR blockade boosts viral outgrowth in CD4+ T cells of people living with HIV-1 (PLWH) receiving antiretroviral therapy (ART). Finally, RNA sequencing reveals genes/pathways downregulated by AhR blockade in CD4+ T cells of ART-treated PLWH, including HIV-1 interactors and gut-homing molecules with AhR-responsive elements in their promoters. Among them, HIC1, a repressor of Tat-mediated HIV-1 transcription and a tissue-residency master regulator, is identified by chromatin immunoprecipitation as a direct AhR target. Thus, AhR governs a T cell transcriptional program controlling viral replication/outgrowth and tissue residency/recirculation, supporting the use of AhR inhibitors in "shock and kill" HIV-1 remission/cure strategies.

The Relationship Between Impaired Coronary Endothelial Function and Systemic Markers of Inflammation in People Living With HIV

BACKGROUND

People with HIV (PWH) are at an increased risk of cardiovascular disease, partially believed to be related to chronically elevated systemic inflammation. Abnormal systemic endothelial function (SEF) and coronary endothelial function (CEF) develop early in atherogenesis and predict adverse events. It is unknown whether abnormal CEF is related to systemic inflammation in PWH.

METHODS

In this substudy of a prior randomized controlled trial in PWH without prior clinical coronary artery disease suppressed on antiretroviral therapy with CEF as a primary end point (N = 82), we investigated the associations between baseline serum markers of inflammation and adhesion and baseline CEF, assessed by noninvasive MRI measures of percentage changes in coronary blood flow and cross-sectional area during isometric handgrip exercise, and SEF using brachial ultrasound for flow-mediated dilation. We also evaluated whether baseline marker levels were associated with CEF after 8 weeks in the placebo group (N = 40).

RESULTS

CEF measures were abnormal at baseline, based on trial entry criteria. A higher value of CEF was directly associated with levels of interleukin 10, whereas CEF at baseline was inversely associated with E-selectin. Worse CEF at 8 weeks was directly associated with baseline tumor necrosis factor alpha, intercellular adhesion molecule 1, C-reactive protein, interferon gamma and sICAM-3. SEF at baseline or 8 weeks was not associated with any baseline markers.

CONCLUSION

Coronary but not systemic endothelial dysfunction was significantly associated with select markers of inflammation and adhesion in PWH. Furthermore, CEF but not SEF at 8 weeks was associated with baseline levels of inflammation. Our findings suggest that abnormal CEF and systemic markers of inflammation are linked in PWH.

The Gut Microbiome, Microbial Metabolites, and Cardiovascular Disease in People Living with HIV

PURPOSE OF REVIEW

To synthesize recent evidence relating the gut microbiome and microbial metabolites to cardiovascular disease (CVD) in people living with HIV (PLWH).

RECENT FINDINGS

A few cross-sectional studies have reported on the gut microbiome and cardiovascular outcomes in the context of HIV, with no consistent patterns emerging. The largest such study found that gut Fusobacterium was associated with carotid artery plaque. More studies have evaluated microbial metabolite trimethylamine N-oxide with CVD risk in PLWH, but results were inconsistent, with recent prospective analyses showing null effects. Studies of other microbial metabolites are scarce. Microbial translocation biomarkers (e.g., lipopolysaccharide binding protein) have been related to incident CVD in PLWH. Microbial translocation may increase CVD risk in PLWH, but there is insufficient and/or inconsistent evidence regarding specific microbial species and microbial metabolites associated with cardiovascular outcomes in PLWH. Further research is needed in large prospective studies integrating the gut microbiome, microbial translocation, and microbial metabolites with cardiovascular outcomes in PLWH.

[Cardiovascular compromise in the infection by the human immunodeficiency virus]

Human immunodeficiency virus (HIV) infection was associated with increased morbidity and mortality, predominantly for opportunistic infections, before using antiretroviral therapy. With this, patients have experienced increased survival and cardiovascular compromise too. The etiology of these clinical conditions could be related to the infection itself, adverse events associated with antiretroviral therapy, or adverse events produced by the combination with other drugs. Some of these conditions have an acute onset, and their rapid recognition is vital for a better prognosis.