Associations between antiretroviral use and subclinical coronary atherosclerosis

Relationships of Liver X Receptor Antagonists and Atherosclerosis in Drinking Water from Six Chinese Major Cities

While environmental factors have been considered contributors to atherosclerosis, it remains unclear whether drinking water promotes foam cell formation, the initial event of atherosclerosis. This study revealed that drinking water from six major cities in China, namely, Harbin, Jinan, Shanghai, Wuhan, Chongqing, and Zhuhai, significantly promoted foam cell formation in an in vitro macrophage model at a minimum concentration fold of 2. Moreover, cholesterol efflux was significantly impeded by all samples at 2-16-fold, while cholesterol influx was induced only by samples from Jinan and Chongqing at 16-fold, suggesting the dominant role of efflux in foam cell formation. Interestingly, except for the sample from Jinan, the samples exhibited complete inhibition of liver X receptor α (LXRα) activities at 160-fold, indicating the potential role of chemicals in drinking water in promoting foam cell formation by antagonizing LXRα. Through LXRα protein affinity selection-mass spectrometry, we identified ten LXRα-binding compounds, with efavirenz being revealed for the first time as a significant inducer of foam cell formation through LXRα antagonism. Overall, this study clarifies the atherosclerotic risks posed by drinking water and demonstrates the efavirenz-related atherosclerotic effects.

High-Sensitivity Troponins and Subclinical Coronary Atherosclerosis Evaluated by Coronary Calcium Score Among Older Asians Living With Well-Controlled Human Immunodeficiency Virus

Background

Elevated levels of high-sensitivity cardiac troponin (hs-cTn) are suggestive of myocardial cell injury and coronary artery disease. We explored the association between hs-cTn and subclinical arteriosclerosis using coronary artery calcification (CAC) scoring among 337 virally suppressed patients with human immunodeficiency virus (HIV) who were ≥50 years old and without evidence of known coronary artery disease.

Methods

Noncontrast cardiac computed tomography and blood sampling for hs-cTn, both subunit I (hs-cTnI) and subunit T (hs-cTnT), were performed. The relationship between CAC (Agatston score) and serum hs-cTn levels was analyzed using Spearman correlation and logistic regression models.

Results

The patients, of whom 62% were male, had a median age of 54 years and had been on antiretroviral therapy for a median of 16 years; the CAC score was >0 in 50% of patients and ≥100 in 16%. Both hs-cTn concentrations were positively correlated with the Agatston score, with correlation coefficients of 0.28 and 0.27 (P < .001) for hs-cTnI and hs-cTnT, respectively. hs-cTnI and hs-cTnT concentrations of ≥4 and ≥5.3 pg/mL, respectively, provided the best performance for discriminating patients with Agatston scores ≥100, with a sensitivity and specificity of 76% and 60%, respectively, for hs-cTnI and 70% and 50% for hs-cTnT. In multivariable logistic regression analysis, each log unit increase in hs-cTnI level was independently associated with increased odds of having an Agatston score ≥100 (odds ratio, 2.83 [95% confidence interval, 1.69-4.75]; P <.001). Although not an independent predictor, hs-cTnT was also associated with an increased odds of having an Agatston score ≥100 (odds ratio, 1.58 [95% confidence interval, .92-2.73]; P = .10).

Conclusions

Among Asians aged ≥50 years with well-controlled HIV infection and without established cardiovascular disease, 50% had subclinical arteriosclerosis. Increasing hs-cTnI and hs-cTnT concentrations were associated with an increased risk of severe subclinical arteriosclerosis, and hs-cTn may be a potential biomarker to detect severe subclinical arteriosclerosis.

Abacavir antiretroviral therapy and indices of subclinical vascular disease in persons with HIV

Objective

Indices of cardiovascular disease (CVD) risk, vascular endothelial dilation, arterial stiffness and endothelial repair were examined in persons with HIV (PWH) on an antiretroviral therapy (ART) that included abacavir (ABC+) in comparison with PWH on ART without abacavir (ABC-), and with HIV seronegative (HIV-) individuals.

Approach

The 115 participants (63% men), aged 30–50 years, did not have CVD, metabolic, endocrine, or chronic renal conditions. PWH were on stable ART for six-months or more. Vascular assessments included flow-mediated dilation (FMD), aortic, radial and femoral arterial stiffness (cAIx, crPWV, cfPWV), and thigh and calf arterial compliance (Vmax50). Endothelial repair was indexed by endothelial progenitor cell colony forming units (EPC-CFU). Traditional CVD risk measures included blood pressure, central adiposity, lipids, insulin resistance (HOMA-IR), CRP and ASCVD score. Analyses controlled for demographics (age, sex, education), medications (antihypertensive, statin/fibrate, antipsychotic), and substance abuse (ASSIST).

Results

No group differences were observed in central adiposity, HOMA-IR, CRP, or ASCVD risk score. However, the ABC- group displayed greater dyslipidemia. The ABC+ group displayed no difference on FMD, cAIx, cfPWV or calf Vmax50 compared with other groups. When CD4 count and viral load were controlled, no additional differences between the ABC+ and ABC- groups emerged. Analyses of crPWV and thigh Vmax50 suggested supported by a trend toward lower EPC-CFU in the HIV+ groups than the HIV- group.

Conclusions

Findings indicate that ABC treatment of 30–50 year-old PWH on stable ART is not likely to contribute in a robust way to higher CVD risk.

Short Communication: Predictive Value of HIV-Related Versus Traditional Risk Factors for Coronary Atherosclerosis in People Aging with HIV

Cardiovascular disease (CVD) is an important cause of morbidity in people living with HIV (PLWH). We compared the predictive value of HIV-related and traditional CVD risk factors to assess which factors best predict the presence of subclinical coronary atherosclerosis in PLWH. This is a cross-sectional study in PLWH over 50 years of age who performed computed tomography coronary artery calcium (CAC) scoring between 2009 and 2019 at Chelsea and Westminster Hospital. The following outcomes were analyzed: CAC = 0 (no calcification), CAC >0 (any calcification), CAC >100 (moderate calcification), and CAC >400 (severe calcification). Univariate and multivariate logistic regression analyses were performed to assess predictors of coronary calcification. A total of 744 patients were included (mean age 56 ± 5.7 years, 94.8% male, 84% white). A CAC >0 was found in 392 (52.7%), CAC >100 in 90 (12.1%), and CAC >400 in 42 (5.6%) subjects. CAC >100 was strongly associated with hypertension [odds ratio, OR: 2.91, (95% confidence interval: 1.93-4.36), p < .001], dyslipidemia [2.71 (1.81-4.06), p < .001], and diabetes [2.53 (1.29-4.96), p = .01]. Regarding HIV-specific factors, a significant association was found with exposure (>6 years) to protease inhibitors [1.67 (1.06-2.61), p = .05], whereas exposure to tenofovir (>8 years) was negatively associated with CAC >100 [0.54 (0.30-0.98), p = .05]. Despite the high prevalence of hypertension (45.4%) only 21.5% were on antihypertensives, whereas only 29.2% of eligible candidates were receiving lipid-lowering drugs for primary prevention of CVD. Traditional cardiometabolic risk factors remain the strongest predictors of coronary atherosclerosis in PLWH as in the general population. These results underscore the importance of optimizing treatment of hypertension and promoting primary prevention strategies that may be underused in PLWH.

Cardiovascular computed tomography and HIV: The evolving role of imaging biomarkers in enhanced risk prediction

The treatment of human immunodeficiency virus (HIV) with antiretroviral (ARV) medications has revolutionised the care for these patients. The dramatic increase in life expectancy has brought new challenges in treating diseases of aging in this cohort. Cardiovascular disease (CVD) is now a leading cause of morbidity and mortality with risk matched HIV-positive patients having double the risk of MI compared to HIV-negative patients. This enhanced risk is secondary to the interplay the virus (and accessory proteins), ARV medications and traditional risk factors. The culmination of these factors can lead to a hybrid metabolic syndrome characterised by heightened ectopic fat. Cardiovascular computed tomography (CT) is ideal for quantifying epicardial adipose tissue volumes, hepatosteatosis and cardiovascular disease burden. The CVD risk attributed to disease burden and plaque morphology is well established in general populations but is less clear in HIV populations. The purpose of this review article is to appraise the latest data on CVD development in HIV-positive patients and how the use of cardiovascular CT may be used to enhance risk prediction in this population. This may have important implications on individualised treatment decisions and risk reduction strategies which will improve the care of these patients.

Cardiovascular risks associated with protease inhibitors for the treatment of HIV

Introduction: Cumulative use of some first-generation protease inhibitors has been associated with higher rates of dyslipidemia and increased risk of cardiovascular disease. The protease inhibitors most commonly in use are atazanavir and darunavir, which have fewer detrimental lipid effects and greater tolerability. This paper aims to review the evidence of a potential association of these contemporary protease inhibitors with the risk of ischemic CVD and atherosclerotic markers.Areas covered: We searched for publications of randomized trials and observational studies on PubMed from 1 January 2000 onwards, using search terms including: protease inhibitors; darunavir; atazanavir; cardiovascular disease; cardiovascular events; dyslipidemia; mortality; carotid intima media thickness; arterial elasticity; arterial stiffness and drug discontinuation. Ongoing studies registered on clinicaltrials.gov as well as conference abstracts from major HIV conferences from 2015-2020 were also searched.Expert opinion: Atazanavir and darunavir are no longer part of first-line HIV treatment, but continue to be recommended as alternative first line, second- and third-line regimens, as part of two drug regimens, and darunavir is used as salvage therapy. Although these drugs will likely remain in use globally for several years to come, baseline CVD risk should be considered when considering their use, especially as the population with HIV ages.

Assessment of Coronary Artery Disease With Computed Tomography Angiography and Inflammatory and Immune Activation Biomarkers Among Adults With HIV Eligible for Primary Cardiovascular Prevention

IMPORTANCE

Cardiovascular disease (CVD) is increased among people with HIV (PWH), but little is known regarding the prevalence and extent of coronary artery disease (CAD) and associated biological factors in PWH with low to moderate traditional CVD risk.

OBJECTIVES

To determine unique factors associated with CVD in PWH and to assess CAD by coronary computed tomography angiography (CTA) and critical pathways of arterial inflammation and immune activation.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study among male and female PWH, aged 40 to 75 years, without known CVD, receiving stable antiretroviral therapy, and with low to moderate atherosclerotic cardiovascular disease (ASCVD) risk according to the 2013 American College of Cardiology/American Heart Association pooled cohort equation, was part of the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE), a large, ongoing primary prevention trial of statin therapy among PWH conducted at 31 US sites. Participants were enrolled from May 2015 to February 2018. Data analysis was conducted from May to December 2020.

EXPOSURE

HIV disease.

MAIN OUTCOMES AND MEASURES

The primary outcome was the prevalence and composition of CAD assessed by coronary CTA and, secondarily, the association of CAD with traditional risk indices and circulating biomarkers, including insulin, monocyte chemoattractant protein 1 (MCP-1), interleukin (IL) 6, soluble CD14 (sCD14), sCD163, lipoprotein-associated phospholipase A2 (LpPLA2), oxidized low-density lipoprotein (oxLDL), and high-sensitivity C-reactive protein (hsCRP).

RESULTS

The sample included 755 participants, with a mean (SD) age of 51 (6) years, 124 (16%) female participants, 267 (35%) Black or African American participants, 182 (24%) Latinx participants, a low median (interquartile range) ASCVD risk (4.5% [2.6%-6.8%]), and well-controlled viremia. Overall, plaque was seen in 368 participants (49%), including among 52 of 175 participants (30%) with atherosclerotic CVD (ASCVD) risk of less than 2.5%. Luminal obstruction of at least 50% was rare (25 [3%]), but vulnerable plaque and high Leaman score (ie, >5) were more frequently observed (172 of 755 [23%] and 118 of 743 [16%], respectively). Overall, 251 of 718 participants (35%) demonstrated coronary artery calcium score scores greater than 0. IL-6, LpPLA2, oxLDL, and MCP-1 levels were higher in those with plaque compared with those without (eg, median [IQR] IL-6 level, 1.71 [1.05-3.04] pg/mL vs 1.45 [0.96-2.60] pg/mL; P = .008). LpPLA2 and IL-6 levels were associated with plaque in adjusted modeling, independent of traditional risk indices and HIV parameters (eg, IL-6: adjusted odds ratio, 1.07; 95% CI, 1.02-1.12; P = .01).

CONCLUSIONS AND RELEVANCE

In this study of a large primary prevention cohort of individuals with well-controlled HIV and low to moderate ASCVD risk, CAD, including noncalcified, nonobstructive, and vulnerable plaque, was highly prevalent. Participants with plaque demonstrated higher levels of immune activation and arterial inflammation, independent of traditional ASCVD risk and HIV parameters.

Antiretroviral Drugs Associated With Subclinical Coronary Artery Disease in the Swiss Human Immunodeficiency Virus Cohort Study

BACKGROUND

Coronary artery disease (CAD) events have been associated with certain antiretroviral therapy (ART) agents. In contrast, the influence of ART on subclinical atherosclerosis is not clear. The study objective was to assess the association between individual ART agents and the prevalence and extent of subclinical CAD.

METHODS

Coronary artery calcium (CAC) scoring and coronary computed tomography angiography (CCTA) were performed in ≥45-year-old Swiss Human Immunodeficiency Virus Cohort Study participants. The following subclinical CAD endpoints were analyzed separately: CAC score >0, any plaque, calcified plaque, noncalcified/mixed plaque, segment involvement score (SIS), and segment severity score (SSS). Logistic regression models calculated by inverse probability of treatment weights (IPTW) were used to explore associations between subclinical CAD and cumulative exposure to the 10 most frequently used drugs.

RESULTS

There were 403 patients who underwent CCTA. A CAC score >0 was recorded in 188 (47%), any plaque in 214 (53%), calcified plaque in 151 (38%), and noncalcified/mixed plaque in 150 (37%) participants. A CAC score >0 was negatively associated with efavirenz (IPTW adjusted odds ratio per 5 years 0.73, 95% confidence interval [CI] 0.56-0.96), tenofovir disoproxil fumarate (0.68, 95% CI 0.49-0.95), and lopinavir (0.64, 95% CI 0.43-0.96). Any plaque was negatively associated with tenofovir disoproxil fumarate (0.71, 95% CI 0.51-0.99). Calcified plaque was negatively associated with efavirenz (0.7, 95% CI 0.57-0.97). Noncalcified/mixed plaque was positively associated with abacavir (1.46, 95% CI 1.08-1.98) and negatively associated with emtricitabine (0.67, 95% CI 0.46-0.99). For SSS and SIS, we found no association with any drug.

CONCLUSIONS

An increased risk of noncalcified/mixed plaque was only found in patients exposed to abacavir. Emtricitabine was negatively associated with noncalcified/mixed plaque, while tenofovir disoproxil fumarate and efavirenz were negatively associated with any plaque and calcified plaque, respectively.

No progression of subclinical atherosclerosis in HIV-infected patients starting an initial regimen including tenofovir alafenamide/emtricitabine plus raltegravir, dolutegravir or elvitegravir/cobicistat during a two-year follow-up

Objectives: Cardiovascular disease has become one of the most common comorbidities among HIV-infected patients, but available data about the correlation between antiretroviral drugs and progression rate of atherosclerotic disease are still limited. We evaluated the progression rate of carotid atherosclerosis in patients starting an initial antiretroviral regimen including one integrase strand transfer inhibitor (INSTI).Methods: Observational, prospective study involving HIV-1-infected, antiretroviral therapy-naive, adult patients who started an antiretroviral regimen including tenofovir alafenamide/emtricitabine (TAF/FTC) plus raltegravir (RAL group), elvitegravir/cobicistat (EVG/c group), or dolutegravir (DTG group). Patients with known cardiovascular disease or diabetes mellitus were excluded from the study. The progression rate of atherosclerosis has been assessed by carotid Doppler ultrasonography at baseline and after 24 months.Results: Overall, 102 patients were enrolled into the study: 73 males, with mean age of 48.7 years: 32, 36 and 34 patients were included in the RAL, EVG/c and DTG groups, respectively. The baseline features of the enrolled patients were comparable across the three groups. At 24 months, the mean intima-media thickness (IMT) increase at the carotid bifurcation was 0.026 mm in the RAL group, 0.029 mm in EVG/c group and 0.032 mm in DTG group. The mean IMT increases after 24 months were comparable across the three groups and statistically not significant in all the evaluated anatomical sites.Conclusions: The initial antiretroviral therapy with TAF/FTC plus RAL, EVG/c or DTG for 24 months led to a comparable and not significant effect on the progression rate of carotid atherosclerosis.

HIV infection and coronary heart disease: mechanisms and management

Antiretroviral therapy has largely transformed HIV infection into a chronic disease condition. As such, physicians and other providers caring for individuals living with HIV infection need to be aware of the potential cardiovascular complications of HIV infection and the nuances of how HIV infection increases the risk of cardiovascular diseases, including acute myocardial infarction, stroke, peripheral artery disease, heart failure and sudden cardiac death, as well as how to select available therapies to reduce this risk. In this Review, we discuss the epidemiology and clinical features of cardiovascular disease, with a focus on coronary heart disease, in the setting of HIV infection, which includes a substantially increased risk of myocardial infarction even when the HIV infection is well controlled. We also discuss the mechanisms underlying HIV-associated atherosclerotic cardiovascular disease, such as the high rates of traditional cardiovascular risk factors in patients with HIV infection and HIV-related factors, including the use of antiretroviral therapy and chronic inflammation in the setting of effectively treated HIV infection. Finally, we highlight available therapeutic strategies, as well as approaches under investigation, to reduce the risk of cardiovascular disease and lower inflammation in patients with HIV infection.

Subclinical Atherosclerosis Imaging in People Living with HIV

In many, but not all studies, people living with HIV (PLWH) have an increased risk of coronary artery disease (CAD) events compared to the general population. This has generated considerable interest in the early, non-invasive detection of asymptomatic (subclinical) atherosclerosis in PLWH. Ultrasound studies assessing carotid artery intima-media thickness (CIMT) have tended to show a somewhat greater thickness in HIV+ compared to HIV−, likely due to an increased prevalence of cardiovascular (CV) risk factors in PLWH. Coronary artery calcification (CAC) determination by non-contrast computed tomography (CT) seems promising to predict CV events but is limited to the detection of calcified plaque. Coronary CT angiography (CCTA) detects calcified and non-calcified plaque and predicts CAD better than either CAC or CIMT. A normal CCTA predicts survival free of CV events over a very long time-span. Research imaging techniques, including black-blood magnetic resonance imaging of the vessel wall and 18F-fluorodeoxyglucose positron emission tomography for the assessment of arterial inflammation have provided insights into the prevalence of HIV-vasculopathy and associated risk factors, but their clinical applicability remains limited. Therefore, CCTA currently appears as the most promising cardiac imaging modality in PLWH for the evaluation of suspected CAD, particularly in patients <50 years, in whom most atherosclerotic coronary lesions are non-calcified.

Associations between lipids and subclinical coronary atherosclerosis

OBJECTIVE

Whether HIV modifies the relationship of serum lipids with coronary atherosclerosis and coronary plaque subtypes is uncertain. We examined the associations between traditional lipids and coronary atherosclerosis among HIV-infected (HIV+) and HIV-uninfected (HIV-) men.

DESIGN

The Multicenter AIDS Cohort Study is an observational cohort with a total of 429 HIV+ and 303 HIV- men who had non-contrast cardiac computed tomography performed to measure coronary artery calcium and coronary computed tomography angiography to measure coronary stenosis, coronary plaque presence, and composition.

METHODS

We used multivariable adjusted prevalence ratios to examine the relationship between the SD difference in each lipid parameter and coronary atherosclerosis.

RESULTS

Total cholesterol (TC)/HDL-cholesterol had the strongest associations with coronary atherosclerosis regardless of HIV status. Overall, lipid parameters were most strongly associated with the presence of mixed plaque, stenosis more than 50%, and coronary artery calcium for both HIV+ and HIV- men. HIV+ men had similar, but weaker associations, between lipid parameters and coronary atherosclerosis compared with HIV- men. The strongest association was between the TC/HDL-cholesterol and stenosis more than 50% for both HIV+ [prevalence ratios 1.25 per SD (95% confidence interval 1.07-1.43)] and HIV- men [prevalence ratios 1.46 per SD (95% confidence interval 1.08-1.85)].

CONCLUSION

The associations between lipids and coronary atherosclerosis tended to be weaker for HIV+ compared with HIV- men, although TC/HDL had the strongest association for both HIV+ and HIV- men. A weaker association between lipid levels and coronary atherosclerosis for HIV+ men may contribute to the decreased discrimination of cardiovascular disease risk observed in HIV+ individuals.

HIV and Aging - Perhaps Not as Dramatic as We Feared?

Ever since the introduction of highly active antiretroviral therapy (ART) in 1995, HIV infection has been linked to "metabolic" complications (insulin resistance, dyslipidemia, osteoporosis, and others). Studies suggested increased rates of myocardial infarction, renal insufficiency, neurocognitive dysfunction, and fractures in HIV-postitive patients. Even long-term suppression of HIV seemed to be accompanied by an excess of deleterious inflammation that could promote these complications. The aims of this viewpoint paper are to summarize recent data and to examine the possibility that the problem of aging-related morbidity in HIV might not be as dramatic as previously believed.

A Review of Long-Term Toxicity of Antiretroviral Treatment Regimens and Implications for an Aging Population

Human immunodeficiency virus (HIV) is a chronic infectious disease currently requiring lifelong antiretroviral therapy (ART). People living with HIV (PLWH) face an increased risk of comorbidities associated with aging, chronic HIV, and the toxicity arising from long-term ART. A literature review was conducted to identify the most recent evidence documenting toxicities associated with long-term ART, particularly among aging PLWH. In general, PLWH are at a greater risk of developing fractures, osteoporosis, renal and metabolic disorders, central nervous system disorders, cardiovascular disease, and liver disease. There remains limited evidence describing the economic burden of long-term ART. Overall, an aging HIV population treated with long-term ART presents a scenario in which the clinical, humanistic, and economic burden for healthcare systems will demand thoughtful policy solutions that preserve access to treatment. Newer treatment regimens with fewer drugs may mitigate some of the cumulative toxicity burden of long-term ART.

Funding: ViiV Healthcare.

Cardiovascular disease and use of contemporary protease inhibitors: the D:A:D international prospective multicohort study

BACKGROUND

Although earlier protease inhibitors have been associated with increased risk of cardiovascular disease, whether this increased risk also applies to more contemporary protease inhibitors is unknown. We aimed to assess whether cumulative use of ritonavir-boosted atazanavir and ritonavir-boosted darunavir were associated with increased incidence of cardiovascular disease in people living with HIV.

METHODS

The prospective Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study consists of people living with HIV-1 from 11 cohorts in Australia, Europe, and the USA. Participants were monitored from Jan 1, 2009, until the earliest of a cardiovascular event, 6 months after the last visit, or until Feb 1, 2016. The outcome of interest was the incidence of cardiovascular disease in adults (aged ≥16 years) living with HIV who were being treated with contemporary treatments. We defined cardiovascular disease as centrally validated myocardial infarction, stroke, sudden cardiac death, or use of invasive cardiovascular procedures, including coronary bypass, coronary angioplasty, and carotid endarterectomy. We used Poisson regression models to assess the associations between cardiovascular disease and the contempoary protease inhibitors atazanavir and darunavir (both boosted with ritonavir).

FINDINGS

49 709 participants were enrolled in the original cohort from 1999 onwards; 35 711 (71·8%) participants with available data on CD4 cell count and viral load at the 2009 baseline were included in the current analysis, and 13 998 (28·2%) participants had insufficent follow-up data after 2009. During a median 6·96 years of follow-up (IQR 6·28-7·08), 1157 people developed cardiovascular disease (incidence rate 5·34 events per 1000 person-years; 95% CI 5·03-5·65). The incidence rate of cardiovascular disease progressively increased from 4·91 events per 1000 person-years (4·59-5·23) in individuals unexposed to ritonavir-boosted darunavir to 13·67 events per 1000 person-years (8·51-18·82) in those exposed to the drug for more than 6 years. The changes associated with ritonavir-boosted atazanavir were less pronounced, showing an incidence rate of 5·03 cardiovascular events per 1000 person-years (4·69-5·37) in unexposed individuals to 6·68 events per 1000 person-years (5·02-8·35) in participants exposed for more than 6 years. After adjustment, keeping factors on the potential causal pathway from boosted protease inhibitor use to cardiovascular disease fixed at baseline, ritonavir-boosted darunavir use was associated with increased risk of cardiovascular disease (incidence rate ratio 1·59; 95% CI 1·33-1·91 per 5 years additional use), but use of ritonavir-boosted atazanavir was not (1·03; 0·90-1·18). This association remained after adjustment for time-updated factors on the potential causal pathway; myocardial infarction and stroke separately; plasma bilirubin concentration; and after stratification by use of ritonavir-boosted darunavir as the first ever protease inhibitor, used in combination with a non-nucleoside reverse transcriptase inhibitor, by previous virological failure, and by those at high risk of cardiovascular disease.

INTERPRETATION

Cumulative use of ritonavir-boosted darunavir, but not of ritonavir-boosted atazanavir, is associated with progressively increasing risk of cardiovascular disease. Causal inference is limited by the observational nature of the D:A:D study. Our findings should prompt investigation into the possible underlying mechanisms of this finding.

FUNDING

The Highly Active Antiretroviral Therapy Oversight Committee.

Abacavir Use and Risk for Myocardial Infarction and Cardiovascular Events: Pooled Analysis of Data From Clinical Trials

Background

Some observational studies and randomized controlled trials (RCTs) have suggested an association between abacavir (ABC) use and myocardial infarction (MI), whereas others have not.

Methods

This pooled analysis of 66 phase II–IV RCTs estimates exposure-adjusted incidence rates (IRs) and relative rates (RRs) of MI and cardiovascular events (CVEs) in participants receiving ABC- and non-ABC-containing combination antiretroviral therapy (cART). The primary analysis of MI included ABC-randomized trials with ≥48-week follow-up. Sensitivity analyses of MI and CVEs included non-ABC-randomized and <48-week follow-up trials.

Results

In 66 clinical trials, 13 119 adults (75% male, aged 18–85 years) were on ABC-containing cART and 7350 were not. Exposure-adjusted IR for MI was 1.5 per 1000 person-years (PY; 95% confidence interval [CI], 0.67–3.34) in the ABC-exposed group and 2.18 per 1000 PY (95% CI, 1.09–4.40) in the unexposed group. The IR for CVEs was 2.9 per 1000 PY (95% CI, 2.09–4.02) in the exposed group and 4.69 per 1000 PY (95% CI, 3.40–6.47) in the unexposed group with studies of ≥48 weeks of follow-up, with an RR of 0.62 (95% CI, 0.39–0.98). The inclusion of nonrandomized and shorter-duration trials did not significantly change the RR for MI or coronary artery disease.

Conclusions

This pooled analysis found comparable IRs for MI and CVEs among ABC-exposed and -unexposed participants, suggesting no increased risk for MI or CVEs following ABC exposure in a clinical trial population. Modifiable risk factors for MI and CVEs should be addressed when prescribing ART.

Positive Expression of Human Cytomegalovirus Phosphoprotein 65 in Atherosclerosis

Previous studies showed that human cytomegalovirus (HCMV) is associated with atherosclerosis. However, local vascular atherosclerosis related HCMV infection and protein expression remain unclear. This study aimed to assess the relationship between HCMV infection and atherosclerosis. Formalin-fixed, paraffin-embedded peripheral artery specimens were obtained from 15 patients with atherosclerosis undergoing vascular surgery from 2008 to 2010 at Zhongnan Hospital, Wuhan University. Pathological analyses were carried out after hematoxylin and eosin (H&E) and Masson trichrome staining. In situ hybridization and immunohistochemistry with two different monoclonal antibodies were employed to detect HCMV nucleic acids and proteins, respectively. H&E and Masson trichrome staining showed homogeneous extracellular matrix in femoral artery, while smooth muscle fibers were interlaced with collagen fibers; in carotid artery, inflammatory cell infiltration, foam cell vascular change, cholesterol crystals, and layered collagen fibers were observed. In situ hybridization showed no expression of HCMV nucleic acids in all 15 cases. Immunohistochemical staining for protein immediate-early protein (IE1 72) was negative in all cases, while phosphoprotein 65 (pp65) expression was detected in 14 cases. A high rate of positive pp65 signals was found in patients with atherosclerosis, suggesting that local HCMV infection may be associated with the pathogenesis of atherosclerosis. Further studies on this relationship are warranted.