Effect of Cumulating Exposure to Abacavir on the Risk of Cardiovascular Disease Events in Patients From the Swiss HIV Cohort Study

Adipose Tissue Dysfunction and Energy Balance Paradigms in People Living With HIV

Over the past 4 decades, the clinical care of people living with HIV (PLWH) evolved from treatment of acute opportunistic infections to the management of chronic, noncommunicable comorbidities. Concurrently, our understanding of adipose tissue function matured to acknowledge its important endocrine contributions to energy balance. PLWH experience changes in the mass and composition of adipose tissue depots before and after initiating antiretroviral therapy, including regional loss (lipoatrophy), gain (lipohypertrophy), or mixed lipodystrophy. These conditions may coexist with generalized obesity in PLWH and reflect disturbances of energy balance regulation caused by HIV persistence and antiretroviral therapy drugs. Adipocyte hypertrophy characterizes visceral and subcutaneous adipose tissue depot expansion, as well as ectopic lipid deposition that occurs diffusely in the liver, skeletal muscle, and heart. PLWH with excess visceral adipose tissue exhibit adipokine dysregulation coupled with increased insulin resistance, heightening their risk for cardiovascular disease above that of the HIV-negative population. However, conventional therapies are ineffective for the management of cardiometabolic risk in this patient population. Although the knowledge of complex cardiometabolic comorbidities in PLWH continues to expand, significant knowledge gaps remain. Ongoing studies aimed at understanding interorgan communication and energy balance provide insights into metabolic observations in PLWH and reveal potential therapeutic targets. Our review focuses on current knowledge and recent advances in HIV-associated adipose tissue dysfunction, highlights emerging adipokine paradigms, and describes critical mechanistic and clinical insights.

Recent abacavir use and incident cardiovascular disease in contemporary-treated people with HIV

OBJECTIVE

Assessing whether the previously reported association between abacavir (ABC) and cardiovascular disease (CVD) remained amongst contemporarily treated people with HIV.

DESIGN

Multinational cohort collaboration.

METHODS

RESPOND participants were followed from the latest of 1 January 2012 or cohort enrolment until the first of a CVD event (myocardial infarction, stroke, invasive cardiovascular procedure), last follow-up or 31 December 2019. Logistic regression examined the odds of starting ABC by 5-year CVD or chronic kidney disease (CKD) D:A:D risk score. We assessed associations between recent ABC use (use within the past 6 months) and risk of CVD with negative binomial regression models, adjusted for potential confounders.

RESULTS

Of 29 340 individuals, 34% recently used ABC. Compared with those at low estimated CVD and CKD risks, the odds of starting ABC were significantly higher among individuals at high CKD risk [odds ratio 1.12 (95% confidence interval = 1.04-1.21)] and significantly lower for individuals at moderate, high or very high CVD risk [0.80 (0.72-0.88), 0.75 (0.64-0.87), 0.71 (0.56-0.90), respectively]. During 6.2 years of median follow-up (interquartile range; 3.87-7.52), there were 748 CVD events (incidence rate 4.7 of 1000 persons-years of follow up (4.3-5.0)]. The adjusted CVD incidence rate ratio was higher for individuals with recent ABC use [1.40 (1.20-1.64)] compared with individuals without, consistent across sensitivity analyses. The association did not differ according to estimated CVD (interaction P  = 0.56) or CKD ( P  = 0.98) risk strata.

CONCLUSION

Within RESPOND's contemporarily treated population, a significant association between CVD incidence and recent ABC use was confirmed and not explained by preferential ABC use in individuals at increased CVD or CKD risk.

Abacavir use is associated with increased prothrombin conversion

There is ongoing debate as to whether abacavir (ABC) increases the risk for cardiovascular disease(CVD) in people living with HIV (PLHIV) and the mechanisms underlying this possible association. We recently showed that the use of an ABC-containing regimen was independently associated with increased thrombin generation (TG). In the present study, we aim to explore these findings further, by studying the mechanistical processes that underly the global thrombin generation test via thrombin dynamics analysis. Thrombin dynamics analysis can pinpoint the cause of increased thrombin generation associated with ABC-use either to the procoagulant prothrombin conversion pathway or the anticoagulant thrombin inactivation pathway. In this cross-sectional study, 208 virally suppressed PLHIV were included, of whom 94 were on a ABC-containing regimen, 92 on a tenofovir disoproxil fumarate (TDF)-containing regimen, and the remainder on other regimens. We used Calibrated Automated Thrombinography to measure thrombin generation and perform thrombin dynamics analysis. The total amount of prothrombin conversion, as well as the maximum rate of prothrombin conversion were significantly increased in PLHIV on an ABC containing regimen compared to other treatment regimens. The levels of pro- and anticoagulant factors were comparable, indicating that the ABC-induced changes affect the kinetics of prothrombin conversion rather than procoagulant factor levels. Moreover, Von Willebrand Factor (VWF), active VWF and VWF pro-peptide levels were significantly higher in PLHIV than controls without HIV. However, they did not differ between ABC and non-ABC treated participants.

CD4:CD8 Ratio and CD8 Cell Count and Their Prognostic Relevance for Coronary Heart Disease Events and Stroke in Antiretroviral Treated Individuals: The Swiss HIV Cohort Study

INTRODUCTION

HIV infection leads to a persistent expansion of terminally CD8 T cells and CD8 T suppressor cells, a marker of chronic immune activation leading to a low CD4:CD8 ratio that may persist in the presence of potent antiretroviral therapy and regained CD4 helper cells. It remains unclear whether a low CD4:CD8 ratio is associated with cardiovascular diseases.

METHODS

We conducted an observational cohort study to investigate the association of immune depression and activation as characterized by the proxy of the CD4:CD8 ratio on the hazard of coronary heart disease (CHD) and stroke among treated individuals living with HIV, while accounting for viral load and known risk factors for cardiovascular diseases and exposure to abacavir or protease inhibitors. We used Cox proportional hazard models with time-dependent cumulative and lagged exposures to account for time-evolving risk factors and avoid reverse causality.

RESULTS

CD4, CD8, and CD4:CD8 immunological markers were not associated with an increased hazard for CHD. CD8 cell count lagged at 12 months above 1000 cells per μL increased the hazard of stroke, after adjusting for sociodemographics, cardiovascular risk factors, and exposure to specific types of antiretroviral drugs.

CONCLUSIONS

This analysis of treated HIV-positive individuals within a large cohort with long-term follow-up does not provide evidence for a prognostic role of immune dysregulation regarding CHD. However, increased CD8 cell count may be a moderate risk factor for stroke. Early detection and treatment of HIV-positive individuals are crucial for an optimal immune restoration and a limited CD8 cells expansion.

Navigating Human Immunodeficiency Virus and Primary Care Concerns Specific to the Transgender and Gender-Nonbinary Population

Human immunodeficiency virus (HIV) prevention and treatment remain critically important to outpatient care among transgender and gender-nonbinary individuals. Epidemiologically, trans men and trans women are significantly more likely to have HIV compared with all adults of reproductive age. Here, we provide an overview of unique primary care considerations affecting transgender and gender-nonbinary individuals, including screening and treatment of HIV and other sexually transmitted infections as well as cancer screening and fertility preservation options. We also seek to review current literature and clinical practice guidelines related to drug–drug interactions between antiretroviral therapy (ART) and gender-affirming hormonal therapy (GAHT). In short, integrase strand transfer inhibitor–based therapy is not expected to have significant drug interactions with most GAHT and is preferred in most transgender individuals, including those on GAHT. Clinicians should also remain aware of current GAHT regimens and consider tailoring ART and GAHT to reduce cardiovascular and other risk factors.

Do contemporary antiretrovirals increase the risk of end-stage liver disease? Signals from patients starting therapy in the North American AIDS Cohort Collaboration on Research and Design

PURPOSE

Despite effective antiretroviral therapy, rates of end-stage liver disease (ESLD) remain high. It is not clear whether contemporary antiretrovirals contribute to the risk of ESLD.

METHODS

We included patients from cohorts with validated ESLD data in the North American AIDS Cohort Collaboration on Research and Design. Patients had to initiate antiretroviral therapy after 1 January 2004 with a nucleos(t)ide backbone of either abacavir/lamivudine or tenofovir/emtricitabine and a contemporary third (anchor) drug. Patients were followed until a first ESLD event, death, end of a cohort's ESLD validation period, loss to follow-up or 31 December 2015. We estimated associations between cumulative exposure to each drug and ESLD using a hierarchical Bayesian survival model with weakly informative prior distributions.

RESULTS

Among 10 564 patients included from 12 cohorts, 62 had an ESLD event. Of the nine anchor drugs, boosted protease inhibitors atazanavir and darunavir had the strongest signals for ESLD, with increasing hazard ratios (HR) and narrowing credible intervals (CrI), from a prior HR of 1.5 (95% CrI 0.32-7.1) per 5 year's exposure to posterior HRs respectively of 1.8 (95% CrI 0.82-3.9) and 2.0 (95% CrI 0.86-4.7). Both backbones and efavirenz showed no signal. Hepatitis C coinfection was the most important covariate risk factor (HR 4.4, 95% CrI 2.6-7.0).

CONCLUSIONS

While contemporary antiretrovirals pose less risk for ESLD than hepatitis coinfection, atazanavir and darunavir had a toxicity signal. We show how hierarchical Bayesian modelling can be used to detect toxicity signals in cohort event monitoring data even with complex treatments and few events.

Increased Circulating Levels of Growth Differentiation Factor 15 in Association with Metabolic Disorders in People Living with HIV Receiving Combined Antiretroviral Therapy

Objective: People living with HIV (PLWH) have an increased cardiovascular risk (CVR) owing to dyslipidemia, insulin resistance, metabolic syndrome, and HIV/combination antiretroviral therapy (cART)-associated lipodystrophy (HALS). Atherosclerosis and inflammation are related to growth differentiation factor-15 (GDF15). The relationship between metabolic disturbances, HALS, and CVR with GDF15 in PLWH is not known. Research design and methods: Circulating GDF15 levels in 152 PLWH (with HALS = 60, without HALS = 43, cART-naïve = 49) and 34 healthy controls were assessed in a cross-sectional study. Correlations with lipids, glucose homeostasis, fat distribution, and CVR were explored. Results: PLWH had increased circulating GDF15 levels relative to controls. The increase was the largest in cART-treated PLWH. Age, homeostatic model assessment of insulin resistance 1 (HOMA1-IR), HALS, dyslipidemia, C-reactive protein, and CVR estimated with the Framingham score correlated with GDF15 levels. The GDF15-Framingham correlation was lost after age adjustment. No correlation was found between GDF15 and the D:A:D Data Collection on Adverse Effects of Anti-HIV Drugs (D:A:D) score estimated CVR. CVR independent predictors were patient group (naïve, HALS−, and HALS+) and cumulated protease inhibitor or nucleoside reverse transcriptase inhibitor exposure. Conclusions: PLWH, especially when cART-treated, has increased GDF15 levels—this increase is associated with dyslipidemia, insulin resistance, metabolic syndrome, HALS, and inflammation-related parameters. GDF15 is unassociated with CVR when age-adjusted.

Acute myocardial infarction associated with abacavir and tenofovir based antiretroviral drug combinations in the United States

INTRODUCTION

Although individual antiretroviral drugs have been shown to be associated with elevated cardiovascular disease (CVD) risk, data are limited on the role of antiretroviral drug combinations. Therefore, we sought to investigate CVD risk associated with antiretroviral drug combinations.

METHODS

Using an administrative health-plan dataset, risk of acute myocardial infarction (AMI) associated with current exposure to antiretroviral drug combinations was assessed among persons living with HIV receiving antiretroviral therapy (ART) across the U.S. from October 2009 through December 2014. To account for confounding-by-indication and for factors simultaneously acting as causal mediators and confounders, we applied inverse probability of treatment weighted marginal structural models to longitudinal data of patients.

RESULTS

Over 114,417 person-years (n = 73,071 persons) of ART exposure, 602 cases of AMI occurred at an event rate of 5.26 (95% CI: 4.86, 5.70)/1000 person-years. Of the 14 antiretroviral drug combinations studied, persons taking abacavir-lamivudine-darunavir had the highest incidence rate (IR: 11/1000; 95% CI: 7.4-16.0) of AMI. Risk (HR; 95% CI) of AMI was elevated for current exposure to abacavir-lamivudine-darunavir (1.91; 1.27-2.88), abacavir-lamivudine-atazanavir (1.58; 1.08-2.31), and tenofovir-emtricitabine-raltegravir (1.35; 1.07-1.71). Tenofovir-emtricitabine-efavirenz was associated with reduced risk (0.65; 0.54-0.78). Abacavir-lamivudine-darunavir was associated with increased risk of AMI beyond that expected of abacavir alone, likely attributable to darunavir co-administration. We did not find an elevated risk of AMI when abacavir-lamivudine was combined with efavirenz or raltegravir.

CONCLUSION

The antiretroviral drug combinations abacavir-lamivudine-darunavir, abacavir-lamivudine-atazanavir and tenofovir-emtricitabine-raltegravir were found to be associated with elevated risk of AMI, while tenofovir-emtricitabine-efavirenz was associated with a lower risk. The AMI risk associated with abacavir-lamivudine-darunavir was greater than what was previously described for abacavir, which could suggest an added risk from darunavir. The results should be confirmed in additional studies.

Meta-Analysis of Efficacy and Safety of Coformulated Bictegravir, Emtricitabine, and Tenofovir Alafenamide Among People Living with HIV

Introduction

Integrase strand transfer inhibitor (InSTI)-based antiretroviral regimens have become the recommended antiretroviral therapy for people living with HIV (PLWH) who are antiretroviral-naïve or stably antiretroviral-treated. This meta-analysis aimed to systematically review the efficacy and safety of coformulated bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) among PLWH.

Methods

Randomized controlled trials (RCTs) were included to compare the efficacy and safety between BIC/FTC/TAF and other antiretroviral regimens containing a non-nucleoside reverse transcriptase inhibitor, protease inhibitor, or integrase strand transfer inhibitor plus two nucleos(t)ide reverse transcriptase inhibitors. A Mantel–Haenszel model was used to investigate the combination or interaction of a group of independent studies. I² was used to determine whether a fixed-effect model or random-effect model was to be used.

Results

A total of seven published randomized clinical trials including 3547 participants were analyzed; three studies were conducted in antiretroviral-naïve PLWH and four in stably antiretroviral-treated PLWH. At week 48, the efficacy with BIC/FTC/TAF was not statistically significantly different from that with control regimens [odds ratio (OR) 1.01 (95% CI 0.79, 1.30)]. BIC/FTC/TAF had comparable safety profiles to control regimens: OR for all adverse effects (AEs) was 0.92 (95% CI 0.78, 1.09); OR for any grade 3 or grade 4 AEs was 0.96 (95% CI 0.66, 1.39); and OR for treatment-related AEs was 1.31 (95% CI 0.68, 2.53).

Conclusions

This meta-analysis of published randomized clinical trials of antiretroviral-naïve and stably antiretroviral-treated PLWH suggests that BIC/FTC/TAF is as safe and efficacious as are its comparators at week 48. The interstudy differences in selected populations and control regimens may lead to the high heterogeneity of the meta-analysis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00449-z.

Association of Incomplete Adherence to Antiretroviral Therapy With Cardiovascular Events and Mortality in Virologically Suppressed Persons With HIV: The Swiss HIV Cohort Study

BACKGROUND

Incomplete antiretroviral therapy (ART) adherence, even if sufficient to maintain viral suppression, is associated with enhanced inflammation in persons with HIV (PWH). However, its clinical implications remain unknown.

METHODS

PWH enrolled in the Swiss HIV Cohort Study without a history of cardiovascular disease (CVD) who initiated ART between 2003 and 2018 and had viral suppression (<50 copies/mL) for ≥6 months were evaluated. The association between incomplete self-reported ART adherence (≥1 or ≥2 missed doses in the last month) and (1) any CVD event (myocardial infarction, revascularization, cerebral hemorrhage, stroke, and/or death due to CVD event) or (2) non-CVD-related death was evaluated using adjusted Cox proportional hazards models.

RESULTS

A total of 6971 PWH (74% male) were included in the analysis (median age [interquartile range {IQR}], 39 [32-47] years). The median (IQR) follow-up was 8 (4-11) years, with 14 (8-23) adherence questionnaires collected per participant. In total, 205 (3%) participants experienced a CVD event, and 186 (3%) died a non-CVD-related death. In an adjusted competing risk model where missing data were imputed, missing ≥1 ART dose showed an increased, but not statistically significant, risk for CVD events (hazard ratio [HR], 1.23; 95% CI, 0.85-1.79; P = .28). Non-CVD-related mortality showed a statistically significantly increased risk with missing ≥1 ART dose (HR, 1.44; 95% CI, 1.00-2.07; P = .05) and missing ≥2 ART doses (HR, 2.21; 95% CI, 1.37-3.57; P = .001).

CONCLUSIONS

Incomplete ART adherence was significantly associated with an increased risk for non-CVD-related mortality in PWH with virologic suppression. This highlights the potential role of nonadherence to ART as a driver of non-AIDS clinical outcomes.

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.

Cardiovascular Events in an Inner-City HIV Clinic and Relationship to Abacavir Versus Tenofovir Disoproxil Fumarate-Containing Antiretroviral Regimens

Following cardiovascular events (CVE) among people living with HIV (PLWH) is essential. Abacavir (ABC)'s impact on CVE challenges clinicians. We characterized CVE at our HIV clinic associated with ABC versus tenofovir disoproxil fumarate (TDF). This was a retrospective study of PLWH who started combination antiretroviral therapy with no prior CVE. Patients were evaluated as antiretroviral naive or antiretroviral experienced. Regimens included the following: always-ABC, always-TDF, first-ABC-switched-to-TDF, and first-TDF-switched-to-ABC regimens. Frequencies, rates, and Poisson regression were used to analyze CVE (cardiovascular/cerebrovascular) and were stratified with an a priori cutoff of before or after January 1, 2009. 1,440/2,852 patients were antiretroviral naive; 658 on always-ABC regimens, 1,186 on always-TDF regimens, 737 first-ABC-switched-to-TDF regimens, and 271 first-TDF-switched-to-ABC regimens. Seventy seven CVE occurred overall [16 naive vs. 61 experienced (p < .0001)]. Sixty events were cardiovascular and 17 cerebrovascular (p < .0001). Sixty-nine CVE occurred before 2009 and eight after (p < .0001). There were 5.65 CVE-per-1,000-years [95% confidence interval (CI) 3.23-9.87] in the always-ABC, 1.95 CVE-per-1,000-years (95% CI 1.08-3.51) in the always-TDF, 2.01 CVE-per-1,000-years (95% CI 1.14-3.56) in the ABC-switched-to-TDF, and 1.82 CVE-per-1,000-years (95% CI 0.77-4.30) in TDF-switched-to-ABC (p <.01). Multivariable Poisson regression incidence rate ratios (IRRs) revealed that being on ABC-only (IRR 2.89; 95% CI 2.13-3.94), age (IRR 1.06 per year; 95% CI 1.04-1.07), and smoking (IRR for current 2.81; 95% CI 1.97-3.99; IRR for former 2.49; 95% CI 1.72-3.61) increased risk of CVE. Thus, in our clinic, CVE rates were increased in those on ABC and adds to the body of literature suggesting concern.

Do Combination Antiretroviral Therapy Regimens for HIV Infection Feature Diverse T-Cell Phenotypes and Inflammatory Profiles?

Immune abnormalities featuring HIV infection persist despite the use of effective combination antiretroviral therapy (cART) and may be linked to the development of noninfectious comorbidities. The aim of the present narrative, nonsystematic literature review is to understand whether cART regimens account for qualitative differences in immune reconstitution. Many studies have reported differences in T-cell homeostasis, inflammation, coagulation, and microbial translocation parameters across cART classes and in the course of triple vs dual regimens, yet such evidence is conflicting and not consistent. Possible reasons for discrepant results in the literature are the paucity of randomized controlled clinical trials, the relatively short follow-up of observational studies, the lack of clinical validation of the numerous inflammatory biomarkers utilized, and the absence of research on the effects of cART in tissues. We are currently thus unable to establish if cART classes and regimens are truly accountable for the differences observed in immune/inflammation parameters in different clinical settings. Questions still remain as to whether an early introduction of cART, specifically in the acute stage of disease, or newer drugs and novel dual drug regimens are able to significantly impact the quality of immune reconstitution and the risk of disease progression in HIV-infected subjects.

The comparative effectiveness of NRTI-sparing dual regimens in emulated trials using observational data from the Swiss HIV Cohort Study

BACKGROUND

Nucleoside (or nucleotide) reverse transcriptase inhibitors (NRTIs) cause side effects in some patients, prompting the use of either partly or fully NRTI-sparing regimens.

METHODS

We used data from the Swiss HIV Cohort Study to estimate the effectiveness of two new dolutegravir dual regimens relative to the alternative NRTI-sparing dual regimens that our clinicians used previously. We emulated two trials by propensity score matching case patients on the dolutegravir regimen with control patients on an alternative regimen. We analysed the case control sets using a Bayesian Cox model and estimated effectiveness as the percentage still on their trial regimen without virological failure at 48 weeks.

RESULTS

In a comparison of partly NRTI-sparing regimens, 58 cases treated with dolutegravir were matched to 17 controls treated with boosted darunavir (both with lamivudine or emtricitabine). The estimated difference in effectiveness was 15% (95% credible interval [CrI] 2-33) and 12% (95% CrI 0-26) in two sequential analyses 1 year apart. In a comparison of fully NRTI-sparing regimens, 54 cases treated with dolutegravir were matched to 32 controls treated with raltegravir (both with boosted darunavir). The estimated difference in effectiveness was 9% (95% CrI -1-21) and 5% (95% CrI -4-15) in the two sequential analyses.

CONCLUSIONS

Estimates of relative effectiveness suggest that both dolutegravir regimens are not inferior to these alternative regimens. All four regimens seem suitable for patients needing an NRTI-sparing regimen: there were few virological failures and few treatment changes due to toxicity.

Investigating the effect of antiretroviral switch to tenofovir alafenamide on lipid profiles in people living with HIV

BACKGROUND

Whilst reporting improved renal and bone safety profiles, studies have noted changes in lipid profiles among people living with HIV (PLWH) receiving antiretroviral therapy (ART) switching away from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF). We aimed to characterize changes in lipids observed after switching to TAF-containing ART in a real-world setting.

METHODS

A prospective study on PLWH enrolled in the UCD-ID Cohort study who switched to TAF-containing ART. Routine laboratory data [including lipids (total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides], ART history and use of lipid-lowering therapy (LLT) were analysed preswitch and postswitch to TAF. Dyslipidaemia was classified according to the National Cholesterol Education Program-Adult Panel III (NCEP-ATP III). Change in lipid parameters and change in the proportion of individuals with dyslipidaemia postswitch was assessed using the paired t-test and the Stuart--Maxwell test, respectively.

RESULTS

Of 775 PLWH enrolled in the cohort, 238 switched to TAF containing ART, of whom 194 had both preswitch and postswitch lipids measured a median (IQR) 24 (14-41) weeks postswitch to TAF. TC, LDL, HDL, triglycerides and TC : HDL ratio significantly increased postswitch [mean change (SE) mmol/l; +0.37 (0.06), P < 0.001; +0.25 (0.06), P < 0.001; +0.05 (0.02), P = 0.003, +0.13 (0.07), P = 0.02, and +0.16 (0.08), P = 0.013) respectively]. There were significant increases in the proportions of PLWH with more severe dyslipidaemia postswitch across TC and LDL (both P < 0.001).

CONCLUSION

These data suggest clinically relevant, worsening lipid profiles postswitch to TAF, with a larger proportion of PLWH exceeding recommended lipid thresholds postswitch. How these changes will impact on cardiovascular risk or need for LLT remains to be determined.

Heterogeneous Patient Preferences for Modern Antiretroviral Therapy: Results of a Discrete Choice Experiment

OBJECTIVE

Limited data describe patient preferences for the growing number of antiretroviral therapies (ARTs). We quantified preferences for key characteristics of modern ART deemed relevant to shared decision making.

METHODS

A discrete choice experiment survey elicited preferences for ART characteristics, including dosing (frequency and number of pills), administration characteristics (pill size and meal requirement), most bothersome side effect (from diarrhea, sleep disturbance, headaches, dizziness/difficulty thinking, depression, or jaundice), and most bothersome long-term effect (from increased risk of heart attacks, bone fractures, renal dysfunction, hypercholesterolemia, or hyperglycemia). Between March and August 2017, the discrete choice experiment was fielded to 403 treatment-experienced persons living with human immunodeficiency virus (HIV), enrolled from 2 infectious diseases clinics in the southern United States and a national online panel. Participants completed 16 choice tasks, each comparing 3 treatment options. Preferences were analyzed using mixed and latent class logit models.

RESULTS

Most participants were male (68%) and older (interquartile range: 42-58 years), and had substantial treatment experience (interquartile range: 7-21 years). In mixed logit analyses, all attributes were associated with preferences. Side and long-term effects were most important, with evidence of substantial preference heterogeneity. Latent class analysis identified 5 preference classes. For classes 1 (40%), 2 (24%), and 3 (21%), side effects were most important, followed by long-term effects. For class 4 (10%), dosing was most important. Class 5 (4%) was largely indifferent to ART characteristics.

CONCLUSION

Overall, treatment-experienced persons living with HIV valued minimizing side effects and long-term toxicities over dosing and administration characteristics. Preferences varied widely, highlighting the need to elicit individual patient preferences in models of shared antiretroviral decision making.

Early scale-up of antiretroviral therapy at diagnosis for reducing economic burden of cardiometabolic disease in HIV-infected population

OBJECTIVE

The current study aims to assess the effect of early scale-up of antiretroviral therapy (ART) at HIV diagnosis on the economic burden of cardiometabolic diseases (CMDs) in HIV-infected population.

DESIGN

Cohort study.

METHODS

The study cohort comprised 10 693 newly diagnosed HIV patients without CMDs before HIV diagnosis identified from a nationwide HIV cohort in Taiwan. The patients were stratified by ART use [medication possession ratio ≥0.8: (high) vs. <0.8: (low)] and AIDS-defining illnesses (ADI) status [present: (+) vs. absent: (-)] at the first year of HIV diagnosis into four groups: ART (low) and ADI (-), ART (low) and ADI (+), ART (high) and ADI (-), and ART (high) and ADI (+). The economic analysis of incident CMDs was from the perspective of Taiwan's single-payer healthcare system and estimated using generalized estimating equations.

RESULTS

CMDs significantly increased annual direct medical costs by 31% (hypertension) to 127% [cardiovascular diseases (CVDs)]. The annual cost burden of diabetes, dyslipidemia, and CVDs in the ART (high) and ADI (-) group significantly decreased by 42, 30, and 31%, respectively, compared with the ART (low) and ADI (+) group. Compared with the ART (low) and ADI (+) group, the annual cost burden of CVDs in the ART (high) and ADI (-) and ART (high) and ADI (+) groups decreased by 31 and 14%, respectively, suggesting increased cost-savings when ART is initiated at diagnosis before ADI occurrence.

CONCLUSION

The early scale-up of ART at diagnosis before ADI occurrence is important for minimizing the economic burden of incident CMDs among HIV-infected patients.

Metabolic Syndrome in HIV/HCV Co-infected Patients

Purpose of review

We review the scope and burden of metabolic syndrome in HIV/HCV co-infected patients, risk factors and potential mechanisms driving the increased cardio-metabolic risk in this population, and discuss relevant clinical considerations for management in the era of highly effective antiretroviral therapy (ART) and curative anti-HCV direct-acting antivirals.

Recent findings

HIV/HCV co-infected patients are at elevated risk of metabolic syndrome, attributed to (1) patient-specific factors, (2) viral-mediated effects, and (3) ART exposure. Risk factors for cardio-metabolic disorders are common in this population and include poor socioeconomic conditions, substance use, cardiovascular comorbidities, and liver/kidney disease. Chronic HIV/HCV infection induces an inflammatory and immune activated state in the host leading to alterations in glucose and lipid metabolism. Selection of life-saving ART must carefully consider the differential metabolic risk associated with each drug class and agent, such as dyslipidemia, hyperglycemia and insulin resistance, weight gain and hypertension. Emerging evidence supports metabolic derangements in chronic HCV may be improved by viral eradication with direct-acting antivirals, however, additional study in HIV/HCV co-infected patients is needed.

Summary

Future research programs should aim to better characterize metabolic syndrome in HIV/HCV co-infected patients with the goal of improved screening, treatment and prevention.

Modeling of cumulative effects of time-varying drug exposures on within-subject changes in a continuous outcome

An accurate assessment of the safety or effectiveness of drugs in pharmaco-epidemiological studies requires defining an etiologically correct time-varying exposure model, which specifies how previous drug use affects the outcome of interest. To address this issue, we develop, and validate in simulations, a new approach for flexible modeling of the cumulative effects of time-varying exposures on repeated measures of a continuous response variable, such as a quantitative surrogate outcome, or a biomarker. Specifically, we extend the linear mixed effects modeling to estimate how past and recent drug exposure affects the way individual values of the outcome change throughout the follow-up. To account for the dosage, duration and timing of past exposures, we rely on a flexible weighted cumulative exposure methodology to model the cumulative effects of past drug use, as the weighted sum of past doses. Weights, modeled with unpenalized cubic regression B-splines, reflect the relative importance of doses taken at different times in the past. In simulations, we evaluate the performance of the model under different assumptions concerning (i) the shape of the weight function, (ii) the sample size, (iii) the number of the longitudinal observations and (iv) the intra-individual variance. Results demonstrate the accuracy of our estimates of the weight function and of the between- and within-patients variances, and good correlation between the observed and predicted longitudinal changes in the outcome. We then apply the proposed method to re-assess the association between time-varying glucocorticoid exposure and weight gain in people living with rheumatoid arthritis.

Metabolic events in HIV-infected patients using abacavir are associated with erythrocyte inosine triphosphatase activity

Objectives

Abacavir use has been associated with an increased risk of cardiovascular disease (CVD) and metabolic events in HIV-infected patients, although this finding was not consistently found. It is unclear whether abacavir only increases this risk in subpopulations of HIV-infected patients. It may be hypothesized that inosine 5'-triphosphate pyrophosphohydrolase (ITPase), an enzyme involved in the metabolism of purine analogues used in HIV treatment, plays a role in the risk of CVD and metabolic events in HIV-infected patients.

Methods

ITPase activity and ITPA genotype were determined in 393 HIV-infected patients. ITPase activity <4 mmol IMP/mmol Hb/h was considered decreased. ITPA polymorphisms tested were: c.94C>A (rs1127354) and c.124 + 21A>C (rs7270101). ORs were determined using generalized estimating equation models for developing CVD in patients who had ever been exposed to abacavir, tenofovir or didanosine and for developing metabolic events in patients currently using these drugs.

Results

In patients using abacavir, metabolic events were associated with ITPase activity. No association was demonstrated for tenofovir or didanosine. The OR for metabolic events was 3.11 in patients using abacavir with normal ITPase activity (95% CI 1.34-7.21; P = 0.008) compared with patients with decreased ITPase activity [adjusted for age, BMI, cumulative duration of combination ART (cART) use and the use of PI and NNRTI]. CVD was not associated with ITPase activity or ITPA genotype.

Conclusions

This study shows, for the first time, that ITPase activity is associated with the occurrence of metabolic events in patients using abacavir. Further studies are needed to confirm this association and to elucidate the possible mechanism.

Electronic medical records can be used to emulate target trials of sustained treatment strategies

OBJECTIVE

To emulate three target trials: single treatment vs. no treatment, joint treatment vs. no treatment, and head-to-head comparison of two treatments, we explain how to estimate the observational analogs of intention-to-treat and per-protocol effects, using hazard ratios and survival curves. For per-protocol effects, we describe two methods for adherence adjustment via inverse-probability weighting.

STUDY DESIGN AND SETTING

Prospective observational study using electronic medical records of individuals aged 55-84 with coronary heart disease from >500 practices in the United Kingdom between 2000 and 2010.

RESULTS

The intention-to-treat mortality hazard ratio (95% confidence interval) was 0.90 (0.84, 0.97) for statins vs. no treatment, 0.88 (0.73, 1.06) for statins plus antihypertensives vs. no treatment, and 0.91 (0.77, 1.06) for atorvastatin vs. simvastatin. When censoring nonadherent person-times, the per-protocol mortality hazard ratio was 0.74 (0.64, 0.85) for statins vs. no treatment, 0.55 (0.35, 0.87) for statins plus antihypertensives vs. no treatment, and 1.13 (0.88, 1.45) for atorvastatin vs. simvastatin. We estimated per-protocol hazard ratios for a 5-year treatment using different dose-response marginal structural models and standardized survival curves for each target trial using intention-to-treat and per-protocol analyses.

CONCLUSION

When randomized trials are not available or feasible, observational analyses can emulate a variety of target trials.

Randomized study evaluating the efficacy and safety of switching from an an abacavir/lamivudine-based regimen to an elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide single-tablet regimen

OBJECTIVE

To evaluate the efficacy and safety of switching from an abacavir/lamivudine (ABC/3TC)-based regimen to an elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) single-tablet regimen in virologically suppressed, HIV-1-infected adults.

DESIGN

Randomized, open-label, noninferiority study.

METHODS

Participants with HIV-1 RNA levels less than 50 copies/ml receiving ABC/3TC plus a third agent for at least 6 months were randomized 2 : 1 to switch immediately to E/C/F/TAF (immediate-switch group) for 48 weeks or to continue receiving ABC/3TC plus a third agent for 24 weeks followed by E/C/F/TAF for 24 weeks (delayed-switch group). The primary endpoint was HIV-1 RNA less than 50 copies/ml at Week 24 by Food and Drug Administration Snapshot algorithm (-12% noninferiority margin).

RESULTS

Baseline characteristics of 274 participants (183 in immediate-switch group and 91 in delayed-switch group) were similar. Virologic response was maintained at Week 24 by 93.4 and 97.8% of participants in the immediate-switch and delayed-switch groups, respectively, with a treatment difference of -4.4% (95% confidence interval: -9.4 to 1.9%), confirming noninferiority. Adverse events of any grade were similar between groups through Week 24 (66% E/C/F/TAF, 64% ABC/3TC); adverse event-related drug discontinuations occurred in 4% of participants switching to E/C/F/TAF (no discontinuations because of renal events) and no participants continuing ABC/3TC. Renal biomarkers of urine albumin:creatinine and beta-2-microglobulin:creatinine ratios significantly improved on E/C/F/TAF. Self-reported treatment satisfaction was significantly higher with E/C/F/TAF.

CONCLUSION

Switching to E/C/F/TAF was noninferior to continuing ABC/3TC plus a third agent for maintenance of HIV RNA suppression at Week 24. This study supports E/C/F/TAF as an efficacious and well tolerated option for participants switching from ABC/3TC-based regimens.

Flexible Modeling of the Association Between Cumulative Exposure to Low-Dose Ionizing Radiation From Cardiac Procedures and Risk of Cancer in Adults With Congenital Heart Disease

Adults with congenital heart disease are increasingly being exposed to low-dose ionizing radiation (LDIR) from cardiac procedures. In a recent study, Cohen et al. (Circulation. 2018;137(13):1334-1345) reported an association between increased LDIR exposure and cancer incidence but did not explore temporal relationships. Yet, the impact of past exposures probably accumulates over years, and its strength may depend on the amount of time elapsed since exposure. Furthermore, LDIR procedures performed shortly before a cancer diagnosis may have been ordered because of early symptoms of cancer, raising concerns about reversal causality bias. To address these challenges, we combined flexible modeling of cumulative exposures with competing-risks methodology to estimate separate associations of time-varying LDIR exposure with cancer incidence and all-cause mortality. Among 24,833 patients from the Quebec Congenital Heart Disease Database, 602 had incident cancer and 500 died during a follow-up period of up to 15 years (1995-2010). Initial results suggested a strong association of cancer incidence with very recent LDIR exposures, likely reflecting reverse causality bias. When exposure was lagged by 2 years, an increased cumulative LDIR dose from the previous 2-6 years was associated with increased cancer incidence, with a stronger association for women. These results illustrate the importance of accurate modeling of temporal relationships between time-varying exposures and health outcomes.

Severe infection increases cardiovascular risk among HIV-infected individuals

BACKGROUND

The identification and management of cardiovascular risk factors became a major clinical issue among HIV-infected individuals in the post-cART era. As in the past decades the link between acute infections and cardiovascular diseases became clear in the general population, we sorted to investigate the role of severe infections on incident cardiovascular diseases (CVDs) among HIV-infected individuals.

METHODS

HIV-infected individuals aged ≥18 years, with no history of CVD were followed from January 2000 to December 2013 until the occurrence of the first CVD event, death or end of study, whichever occurred first. To explore the effect of severe infections on the incidence of CVD we used extended Cox regression models and stratified post-hospitalization follow-up time into three periods: < 3 months, 3-12 months and > 12 months post discharge.

RESULTS

One hundred-eighty four persons from 3384 HIV-infected individuals developed incident CVD events during the follow-up (incidence rate = 11.10/1000 PY (95%CI: 9.60-12.82)). Risk of an incident CVD was 4-fold higher at < 3 months post-hospitalization for severe infections (adjusted hazard ratio [aHR], 4.52; 95% confidence interval [CI] 2.46-8.30), after adjusting for sociodemographic and clinical factors as well as comorbidities. This risk remained significant up to one year (3-12 months post hospital discharge aHR 2.39, 95% CI 1.30-4.38). Additionally, non-white race/ethnicity (aHR 1.49, 95% CI 1.10-2.02), age ≥ 60 years (aHR 2.01, 95% CI 1.01-3.97) and hypertension (aHR 1.90, 95% CI 1.38-2.60) were associated with an increased risk of CVD events. High CD4 (≥ 500 cells/mm3: aHR 0.41, 95% CI 0.27-0.62) and cART use (aHR 0.21, 95% CI 0.14-0.31) reduced the risk of CVD events.

CONCLUSIONS

We provide evidence for a time-dependent association between severe infection and incident cardiovascular disease in HIV-infected individuals. cART use, and high CD4 count were significantly associated with reduced hazards of CVD.

Cumulative Human Immunodeficiency Viremia, Antiretroviral Therapy, and Incident Myocardial Infarction

BACKGROUND

People living with HIV are at risk of increased myocardial infarction (MI). Cumulative HIV viral load (VL) has been proposed as a better measure of HIV inflammation than other measures of VL, like baseline VL, but its associations with MI are not known.

METHODS

The multisite Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort includes clinical data and centrally adjudicated MI with distinction between atheroembolic MI (type 1) and MI related to supply-demand mismatch (type 2). We examined CNICS participants who were not on antiretroviral therapy (ART) at enrollment. Cumulative VL (copy-days of virus) from 6 months after enrollment was estimated with a time-weighted sum using the trapezoidal rule. We modeled associations of cumulative and baseline VL with MI by type using marginal structural Cox models. We contrasted the 75% percentile of the VL distribution with the 25% percentile.

RESULTS

Among 11,324 participants, 218 MIs occurred between 1996 and 2016. Higher cumulative VL was associated with risk of all MI (hazard ratio [HR] = 1.72; 95% confidence interval [CI] = 1.26, 2.36), type 1 MI (HR = 1.23; 95% CI = 0.78, 1.96), and type 2 MI (HR = 2.52; 95% CI = 1.74, 3.66). While off ART, cumulative VL had a stronger association with type 1 MI (HR = 2.13; 95% CI = 1.15, 3.94) than type 2 MI (HR = 1.25; 95% CI = 0.70, 2.25). Baseline VL was associated with all MI (HR = 1.60; 95% CI = 1.28, 2.01), type 1 MI (HR = 1.73; 95% CI = 1.26, 2.38), and type 2 MI (HR = 1.51; 95% CI = 1.10, 2.08).

CONCLUSIONS

Higher cumulative and baseline VL is associated with all MI, with a particularly strong association between cumulative VL and type 2 MI.

Hypertension Risk with Abacavir Use among HIV-Infected Individuals: A Nationwide Cohort Study

PURPOSE

A high risk of cardiovascular disease (CVD) is reported for HIV-infected individuals. While a link between abacavir and CVD risk is suggested, an association between abacavir and hypertension remains unclear. This study evaluated hypertension risk with abacavir use in comparison to non-abacavir antiretroviral treatment (ART).

MATERIALS AND METHODS

From a nationwide cohort of HIV-infected individuals on their initial ART, 6493 who were free of hypertension at baseline were analyzed. The use of ART was treated as a time-varying covariate measured as a daily unit. Incidence rate of hypertension was calculated, and Cox proportional hazard models were used to estimate adjusted hazard ratios (HRs) with 95% confidence interval (CI) of incident hypertension overall and among subgroups.

RESULTS

From the 6493 participants, 24072 person-years (PY) of follow-up were contributed during 2008-2016. The incidence rates of hypertension were 4.6 and 3.6 per 100 PY for abacavir and non-abacavir ART users, respectively. The population attributable fraction of abacavir use on hypertension was 12%. Abacavir exposure did not elevate the risk of hypertension among overall study population [HR, 1.2 (95% CI, 1.0-1.4), p=0.061]. However, those with poor ART adherence, defined as a medication possession ratio <50% [HR, 1.9 (95% CI, 1.5-2.4), p<0.0001] or requiring prophylactic antibiotics [HR, 1.2 (95% CI, 1.0-1.3), p=0.023], were at risk of hypertension induced by abacavir, as were men, individuals aged ≥40 years, and patients visiting tertiary hospitals in urban areas.

CONCLUSION

When present, poor ART adherence, requiring prophylactic antibiotics, male sex, and older age may warrant additional concern for hypertension in patients treated with abacavir.

Managing antiretroviral therapy in the elderly HIV patient

Introduction: Owing to more effective and less toxic antiretroviral therapy (ART), people living with HIV (PLWH) live longer, a phenomenon expected to grow in the next decades. With advancing age, effectively treated PLWH experience not only a heightened risk for non-infective comorbidities and multimorbidity, but also for geriatric syndromes and frailty. In addition, older adults living with HIV (OALWH) have a higher prevalence of so-called iatrogenic triad described as polypharmacy (PP), potentially inappropriate medication use, and drug-drug interactions. Areas covered: This review will focus the management of ART in OALWH. We will discuss iatrogenic triad and best way to address PP. Special focus will be given to pharmacokinetic and pharmacodynamic aspects of ART in the elderly, evaluation of ART toxicities, and specific ART strategies commonly used in this population. Expert commentary: Research should be focused on recruiting more OALWH, frail individuals in particular, into the clinical trials and specific geriatric outcome need to be considered together with traditional viroimmunological outcomes.

Risk of cardiovascular disease associated with exposure to abacavir among individuals with HIV: A systematic review and meta-analyses of results from 17 epidemiologic studies

OBJECTIVES

Abacavir's potential to cause cardiovascular disease (CVD) among people living with HIV (PLWH) is debated. We conduct a systematic review and meta-analyses to assess CVD risk from recent and cumulative abacavir exposure.

METHODS

We searched Medline, Embase, Web of Science, abstracts from Conference on Retroviruses and Opportunistic Infections, and International AIDS Society/AIDS Conferences and bibliographies of review articles to identify research studies published through 2018 on CVD risk associated with abacavir exposure among PLWH. Studies assessing risk of CVD associated with recent (exposure within last 6 months) or cumulative abacavir exposure across all age-groups were eligible. Risks were quantified using fixed- and random-effects models.

RESULTS

Of 378 unique citations, 68 full-text research articles and abstracts were reviewed. Seventeen studies assessed risk of CVD from recent or cumulative abacavir exposure. Summary relative risk (sRR) is increased for recent exposure (n=16 studies, sRR=1.61; 95% confidence interval: 1.48-1.75), higher in antiretroviral-therapy-naive population (n=5, 1.91; 1.48-2.46) and all studies reported RR>1. The sRR for recent exposure was similarly increased for the outcome of acute myocardial infarction, and for studies that adjusted for substance abuse, smoking, prior CVD, traditional CVD risk factors, and CD4 cell-count/HIV viral load. The sRR was increased for cumulative abacavir exposure (per year) (n=4, 1.12; 1.05-1.20) but no increase was seen after adjusting for recent exposure (n=5, 1.00; 0.93-1.08).

CONCLUSIONS

Our findings suggest an increased risk of CVD from recent abacavir exposure. The risk remained elevated after adjusting for potential confounders. Further investigations are needed to understand CVD risk from cumulative exposure.

Biochemical and inflammatory modifications after switching to dual antiretroviral therapy in HIV-infected patients in Italy: a multicenter retrospective cohort study from 2007 to 2015

BACKGROUND

Triple-drug regimens are the gold standard for HIV therapy. Nucleos(t)ide reverse transcriptase inhibitors (NRTIs) reducing regimens are used to decrease drugs toxicity, exposure and costs. Aim of our study was to evaluate trends of biochemical and inflammatory indices in patients switching to dual therapy (DT).

METHODS

We included patients that a) switched to a DT from 2007 to 2015 from a tenofovir/abacavir-based triple regimen b) previously maintained a triple and c) subsequently a dual regimen for 12 months with virological suppression. We retrieved data measured at 5 points (at the switch, 6 and 12 months before and after switch). We used platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR) and CD4/CD8 ratio as inflammatory indices. We assessed temporal trends of viro-immunological, biochemical and inflammatory parameters.

RESULTS

Overall, 364 and 65 patients switched from a tenofovir- and an abacavir-triple regimen, respectively. In the tenofovir-reducing group, creatinine clearance and lipids raised after the switch. There was a significant increase in both CD4+ cells and CD4/CD8. CD8+ cells rose after the switch, while opposite trend was found for PLR. In the abacavir-reducing group total lipids showed a decrease during the first 6 months after the switch and then stabilized. An increase of CD4+ and a decrease of CD8+ cells was observed during the study period, although not statistically significant. While CD4/CD8 remained stable after simplification, PLR decreased significantly after 6 months, then returning to baseline. CD8+ cells increased in the tenofovir-reducing group despite a viro-immunological response. Intriguingly, PLR decreased, maintaining this trend for 12 and 6 months after tenofovir and abacavir interruption respectively.

CONCLUSIONS

Increased PLR has been linked to hypercholesterolemia and metabolic-syndrome, while high CD8+ cells count to increased risk of non-AIDS-related events regardless of CD4 T-cell recovery and to virological failure. Whether these findings may have clinical implications, and which role DT plays on the immune system and on inflammation should be further investigated.

Use of digoxin in atrial fibrillation: One step further in the mortality controversy from the AFFIRM study

BACKGROUND

Whether there is a causal association between digoxin and mortality among patients with atrial fibrillation (AF), with or without congestive heart failure (HF), has been controversial; in particular, two prior analyses of data from the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial have yielded conflicting results. We sought to investigate how digoxin impacts mortality, in the full AFFIRM cohort and for various subgroups, by applying marginal structural modeling (MSM) to AFFIRM data.

METHODS

MSM is a newer statistical approach, which estimates causal association in the absence of randomization. MSM more effectively accounts for time-varying treatment and mitigates potential biases, in contrast to the two statistical approaches used in prior analyses of the AFFIRM data.

RESULTS

Among 4,060 patients in AFFIRM, 660 (16.3%) died during follow-up. Digoxin was associated with significantly higher mortality in the full cohort (estimated hazard ratio [HR] 1.33, 95% confidence interval [CI] 1.11-1.60, P  =  0.002) and in 3,121 patients without HF (HR 1.36, 95% CI 1.07-1.72, P  =  0.011). There was a trend toward higher mortality with digoxin in 939 patients with HF (HR 1.29, 95% CI 0.96-1.72, P  =  0.090). Associations were nonsignificant in 463 patients with HF and left ventricular ejection fraction (EF) ≥40% and in 155 patients with EF ≤30%.

CONCLUSIONS

Digoxin is associated with significantly increased mortality among AFFIRM patients collectively, as determined by MSM statistical methodology. However, the impact of digoxin among AFFIRM patients with coexisting HF is inconclusive.

Recent Abacavir Use Increases Risk of Type 1 and Type 2 Myocardial Infarctions Among Adults With HIV

BACKGROUND

There is persistent confusion as to whether abacavir (ABC) increases the risk of myocardial infarction (MI), and whether such risk differs by type 1 (T1MI) or 2 (T2MI) MI in adults with HIV.

METHODS

Incident MIs in North American Cohort Collaboration on Research and Design participants were identified from 2001 to 2013. Discrete time marginal structural models addressed channeling biases and time-dependent confounding to estimate crude hazard ratio (HR) and adjusted hazard ratio (aHR) and 95% confidence intervals; analyses were performed for T1MI and T2MI separately. A sensitivity analysis evaluated whether Framingham risk score (FRS) modified the effect of ABC on MI occurrence.

RESULTS

Eight thousand two hundred sixty-five adults who initiated antiretroviral therapy contributed 29,077 person-years and 123 MI events (65 T1MI and 58 T2MI). Median follow-up time was 2.9 (interquartile range 1.4-5.1) years. ABC initiators were more likely to have a history of injection drug use, hepatitis C virus infection, hypertension, diabetes, impaired kidney function, hyperlipidemia, low (<200 cells/mm) CD4 counts, and a history of AIDS. The risk of the combined MI outcome was greater for persons who used ABC in the previous 6 months [aHR = 1.84 (1.17-2.91)]; and persisted for T1MI (aHR = 1.62 [1.01]) and T2MI [aHR = 2.11 (1.08-4.29)]. FRS did not modify the effect of ABC on MI (P = 0.14) and inclusion of FRS in the MSM did not diminish the effect of recent ABC use on the combined outcome.

CONCLUSIONS

Recent ABC use was associated with MI after adjustment for known risk factors and for FRS. However, screening for T1MI risks may not identify all or even most persons at risk of ABC use-associated MIs.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSION

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

Aging in HIV-Infected Subjects: A New Scenario and a New View

The prevalence of HIV-infected people aged 50 years or older is increasing rapidly; the proportion will increase from 28% to 73% in 2030. In addition, HIV-infected individuals may be more vulnerable to age-related condition. There is growing evidence that the prevalence of comorbidities and other age-related conditions (geriatric syndromes, functional or neurocognitive/mental problems, polypharmacy, and social difficulties) is higher in the HIV-infected population than in their uninfected counterparts. However, despite the potential impact of this situation on health care, little information exists about the optimal clinical management of older HIV-infected people. Here we examine the age-related conditions in older HIV-infected persons and address clinical management according to author expertise and published literature. Our aim is to advance the debate about the most appropriate management of this population, including less well-studied aspects, such as frequency of screening for psychological/mental and social and functional capabilities.

Metabolic and Cardiovascular Complications in HIV/HCV-Co-infected Patients

PURPOSE OF REVIEW

Fifteen to thirty percent of HIV-infected persons in North America and Europe are co-infected with chronic hepatitis C (HCV). The latter is associated with a significant number of extra-hepatic metabolic complications that could compound HIV-associated increased cardiovascular risk. This article reviews the basic science and epidemiologic and clinical evidence for increased cardio-metabolic risk among HIV/HCV-co-infected patients and discusses potential underlying mechanisms. We will finally review the impact of control of HCV viremia on the cardio-metabolic morbidity and mortality of HIV/HCV-co-infected patients.

RECENT FINDINGS

HCV infection is associated with a number of immune-related complications such as cryoglobulinemia but also metabolic complications including dyslipidemias, hepatic steatosis, insulin resistance, diabetes, and chronic kidney disease. The incidence of these complications is higher among HIV-co-infected patients and might contribute to increased mortality. The potential mechanisms of increased cardiovascular risk among HIV/HCV-co-infected subjects include endothelial dysfunction, chronic inflammation and immune activation, the cardio-metabolic effects of HCV-induced hepatic steatosis and fibrosis or insulin resistance, and chronic kidney disease. However, epidemiologic studies show discordant findings as to whether HCV co-infection further increases the risk of atherosclerotic cardiovascular diseases (acute myocardial infarctions and strokes) among HIV-infected patients. Nonetheless, successful treatment of HCV is associated with significant improvements in cardio-metabolic risk factors including diabetes mellitus. HCV co-infection is associated with a higher incidence of metabolic complications-and likely increased risk of cardiovascular events-that might contribute to increased mortality in HIV. These appear to improve with successful HCV therapy.

Bictegravir, emtricitabine, and tenofovir alafenamide versus dolutegravir, abacavir, and lamivudine for initial treatment of HIV-1 infection (GS-US-380-1489): a double-blind, multicentre, phase 3, randomised controlled non-inferiority trial

BACKGROUND

Integrase strand transfer inhibitors (INSTIs) are recommended components of initial antiretroviral therapy with two nucleoside reverse transcriptase inhibitors. Bictegravir is a novel, potent INSTI with a high in-vitro barrier to resistance and low potential as a perpetrator or victim of clinically relevant drug-drug interactions. We aimed to assess the efficacy and safety of bictegravir coformulated with emtricitabine and tenofovir alafenamide as a fixed-dose combination versus coformulated dolutegravir, abacavir, and lamivudine.

METHODS

We did this double-blind, multicentre, active-controlled, randomised controlled non-inferiority trial at 122 outpatient centres in nine countries in Europe, Latin America, and North America. We enrolled HIV-1 infected adults (aged ≥18 years) who were previously untreated (HIV-1 RNA ≥500 copies per mL); HLA-B*5701-negative; had no hepatitis B virus infection; screening genotypes showing sensitivity to emtricitabine, tenofovir, lamivudine, and abacavir; and an estimated glomerular filtration rate of 50 mL/min or more. Participants were randomly assigned (1:1), via a computer-generated allocation sequence (block size of four), to receive coformulated bictegravir 50 mg, emtricitabine 200 mg, and tenofovir alafenamide 25 mg or coformulated dolutegravir 50 mg, abacavir 600 mg, and lamivudine 300 mg, with matching placebo, once daily for 144 weeks. Randomisation was stratified by HIV-1 RNA (≤100 000 copies per mL, >100 000 to ≤400 000 copies per mL, or >400 000 copies per mL), CD4 count (<50 cells per μL, 50-199 cells per μL, or ≥200 cells per μL), and region (USA or ex-USA). Investigators, participants, and study staff giving treatment, assessing outcomes, and collecting data were masked to group assignment. The primary endpoint was the proportion of participants with plasma HIV-1 RNA less than 50 copies per mL at week 48, as defined by the US Food and Drug Administration snapshot algorithm, with a prespecified non-inferiority margin of -12%. All participants who received one dose of study drug were included in primary efficacy and safety analyses. This trial is registered with ClinicalTrials.gov, number NCT02607930.

FINDINGS

Between Nov 13, 2015, and July 14, 2016, we randomly assigned 631 participants to receive coformulated bictegravir, emtricitabine, and tenofovir alafenamide (n=316) or coformulated dolutegravir, abacavir, and lamivudine (n=315), of whom 314 and 315 patients, respectively, received at least one dose of study drug. At week 48, HIV-1 RNA less than 50 copies per mL was achieved in 92·4% of patients (n=290 of 314) in the bictegravir, emtricitabine, and tenofovir alafenamide group and 93·0% of patients (n=293 of 315) in the dolutegravir, abacavir, and lamivudine group (difference -0·6%, 95·002% CI -4·8 to 3·6; p=0·78), demonstrating non-inferiority of bictegravir, emtricitabine, and tenofovir alafenamide to dolutegravir, abacavir, and lamivudine. No individual developed treatment-emergent resistance to any study drug. Incidence and severity of adverse events was mostly similar between groups except for nausea, which occurred less frequently in patients given bictegravir, emtricitabine, and tenofovir alafenamide than in those given dolutegravir, abacavir, and lamivudine (10% [n=32] vs 23% [n=72]; p<0·0001). Adverse events related to study drug were less common with bictegravir, emtricitabine, and tenofovir alafenamide than with dolutegravir, abacavir, and lamivudine (26% [n=82] vs 40% [n=127]), the difference being driven by a higher incidence of drug-related nausea in the dolutegravir, abacavir, and lamivudine group (5% [n=17] vs 17% [n=55]; p<0·0001).

INTERPRETATION

At 48 weeks, coformulated bictegravir, emtricitabine, and tenofovir alafenamide achieved virological suppression in 92% of previously untreated adults and was non-inferior to coformulated dolutegravir, abacavir, and lamivudine, with no treatment-emergent resistance. Bictegravir, emtricitabine, and tenofovir alafenamide was safe and well tolerated with better gastrointestinal tolerability than dolutegravir, abacavir, and lamivudine. Because coformulated bictegravir, emtricitabine, and tenofovir alafenamide does not require HLA B*5701 testing and provides guideline-recommended treatment for individuals co-infected with HIV and hepatitis B, this regimen might lend itself to rapid or same-day initiation of therapy in the clinical setting.

FUNDING

Gilead Sciences.

Risk of cardiovascular events from current, recent, and cumulative exposure to abacavir among persons living with HIV who were receiving antiretroviral therapy in the United States: a cohort study

BACKGROUND

There is ongoing controversy regarding abacavir use in the treatment of HIV infection and the risk of subsequent development of cardiovascular disease. It is unclear how the risk varies as exposure accumulates.

METHODS

Using an administrative health-plan dataset, risk of cardiovascular disease events (CVDe), defined as the first episode of an acute myocardial infarction or a coronary intervention procedure, associated with abacavir exposure was assessed among HIV-infected individuals receiving antiretroviral therapy across the U.S. from October 2009 through December 2014. The data were longitudinal, and analyzed using marginal structural models.

RESULTS

Over 114,470 person-years (n = 72,733) of ART exposure, 714 CVDe occurred at an incidence rate (IR) (95% CI) of 6·23 (5·80, 6·71)/1000 person-years. Individuals exposed to abacavir had a higher IR of CVDe of 9·74 (8·24, 11·52)/1000 person-years as compared to 5·75 (5·30, 6·24)/1000 person-years for those exposed to other antiretroviral agents. The hazard (HR; 95% CI) of CVDe was increased for current (1·43; 1·18, 1·73), recent (1·41; 1·16, 1·70), and cumulative [(1·18; 1·06, 1·31) per year] exposure to abacavir. The risk for cumulative exposure followed a bell-shaped dose-response curve peaking at 24-months of exposure. Risk was similarly elevated among participants free of pre-existing heart disease or history of illicit substance use at baseline.

CONCLUSION

Current, recent, and cumulative use of abacavir was associated with an increased risk of CVDe. The findings were consistent irrespective of underlying cardiovascular risk factors.

Coronary Artery Disease in HIV-Infected Patients: Downside of Living Longer

PURPOSE OF REVIEW

Introduction of combination antiretroviral therapy (ART) has increased the life expectancy of patients with HIV infection, allowing them to live longer with this chronic medical condition and consequently experiencing conditions such as cardiovascular diseases (CVDs). Several studies have investigated the increased risk of CVD in people living with HIV (PLWH). However, less is known about the exact mechanisms involved in this increased risk. Also, specific guidelines for management of CVD in PLWH have not been developed yet. In this article, we review the recent literature on the mechanisms involved in pathogenesis of CVD in PLWH, with an emphasis on coronary artery disease (CAD).

RECENT FINDINGS

Although initial studies suspected the increased prevalence of traditional CVD risk factors and side effects of ART to be involved in the increased CVD risk in PLWH, recent studies have uncovered the important role of chronic persistent inflammation in this increased risk. In addition, biomarkers of inflammation have been associated with both CVD events and subclinical CAD in this population. Lastly, recent studies and ongoing clinical trials have been investigating medical interventions that aim to reduce inflammation and cardiovascular events. Different mechanisms of inflammation have been examined in PLWH, including subclinical viremia, microbial translocation, and coinfection with other pathogens such as cytomegalovirus. Although inflammatory biomarkers have been consistently associated with CVD and subclinical CVD outcomes, their prognostic value is unknown. Recent and ongoing trials are exploring the benefits of anti-inflammatory drugs, statins, and antimicrobial translocation drugs on both inflammation and CVD risk among PLWH.

Competing risks modeling of cumulative effects of time-varying drug exposures

An accurate assessment of drug safety or effectiveness in pharmaco-epidemiology requires defining an etiologically correct time-varying exposure model, which specifies how previous drug use affects the hazard of the event of interest. An additional challenge is to account for the multitude of mutually exclusive events that may be associated with the use of a given drug. To simultaneously address both challenges, we develop, and validate in simulations, a new approach that combines flexible modeling of the cumulative effects of time-varying exposures with competing risks methodology to separate the effects of the same drug exposure on different outcomes. To account for the dosage, duration and timing of past exposures, we rely on a spline-based weighted cumulative exposure modeling. We also propose likelihood ratio tests to test if the cumulative effects of past exposure on the hazards of the competing events are the same or different. Simulation results indicate that the estimated event-specific weight functions are reasonably accurate, and that the proposed tests have acceptable type I error rate and power. In real-life application, the proposed method indicated that recent use of antihypertensive drugs may reduce the risk of stroke but has no effect on the hazard of coronary heart disease events.

Cardiovascular toxicity of abacavir: a clinical controversy in need of a pharmacological explanation

: There is a long-lasting controversy surrounding an association between abacavir (ABC) and an increased risk of cardiovascular disease in HIV-positive patients. Although differing in their specifics, a number of published cohort studies and clinical trials support such an association, usually relating it to recent exposure to the drug, independently of traditional predisposing factors. However, other clinical trials have failed to reveal such a relation and have pointed to methodological differences to explain discrepancies. Significantly, the controversy has been fueled by the lack of a credible mechanism of action to justify the putative detrimental actions of ABC. There is a myriad of contradictory clinical indicators which are not clearly compatible with known profiles of either vascular physiopathology or pharmacological interference. However, basic research has recently hinted at altered homeostatic mechanisms, though this requires clinical validation. In particular, recurrent evidence - both clinical and experimental - relates ABC with vascular inflammation, a leading contributor to the atherosclerotic plaque and thrombosis. ABC's chemical structure is very close to that of endogenous purines (ATP, ADP and AMP), major paracrine signaling molecules capable of triggering prothrombotic and proinflammatory vascular programs. Other proposed mechanisms are a competitive inhibition of guanylyl cyclase in platelets and a subsequent decrease in cyclic guanosine monophosphate (cGMP). The present review aims to shed light on this complex subject by summarizing and critically evaluating all the available clinical data regarding a relationship between ABC and cardiovascular disease, and to put forward potential pharmacological explanations compatible with both the clinical scenario and experimental findings.

Nucleoside reverse transcriptase inhibitor-reducing strategies in HIV treatment: assessing the evidence

Antiretroviral (ARV) therapy, comprising a backbone of two nucleos(t)ide reverse transcriptase inhibitors (NRTIs) plus another ARV, is the recognized standard of care (SOC), which has helped extend life expectancy in people living with HIV. In a quest to reduce lifelong drug exposure and minimize or avoid the toxicity of NRTIs, "NRTI-reducing" regimens have been investigated. This descriptive review assessing the results of NRTI-reducing strategies from the largest randomized trials focuses on virological efficacy, resistance, regimen safety (in terms of bone mineral density, renal function, lipids and central nervous system function) and simplicity. The review considers efficacy across various NRTI-sparing strategies, for example an integrase strand transfer inhibitor (INSTI) plus a ritonavir-boosted protease inhibitor (PI/r) or PI/r + lamivudine (3TC), in both naïve and switch regimes. Of 10 key studies in treatment-naïve adults assessing five NRTI-reducing strategies, only four studies demonstrated noninferiority vs. SOC [GARDEL, NEAT 001, AIDS Clinical Trials Group 5142 and PROGRESS]. In switch settings, 17 studies (10 randomized) were reviewed that used four strategies, including three studies assessing an INSTI plus a nonnucleoside reverse transcriptase inhibitor . Noninferiority of the NRTI-reducing arm was shown in six of 10 studies (ATLAS-M, SALT, DUAL, OLE, LATTE-2 and SWORD). In general, NRTI-reducing therapy did not always result in an improvement in short- or long-term adverse events; however, in many cases, these endpoints were not reported. Some of these studies reported higher virological failure rates with more frequent emergence of resistance mutations. None of these NRTI-reducing strategies has been compared against a single-pill regimen, including those containing tenofovir alafenamide. Only strategies demonstrating noninferior efficacy, a benefit in safety/tolerability, and a favourable cost-efficacy ratio, preferably in a single pill, will eventually match the current SOC of triple ARV therapy.

Using Multiple Pharmacovigilance Models Improves the Timeliness of Signal Detection in Simulated Prospective Surveillance

INTRODUCTION

Prospective pharmacovigilance aims to rapidly detect safety concerns related to medical products. The exposure model selected for pharmacovigilance impacts the timeliness of signal detection. However, in most real-life pharmacovigilance studies, little is known about which model correctly represents the association and there is no evidence to guide the selection of an exposure model. Different exposure models reflect different aspects of exposure history, and their relevance varies across studies. Therefore, one potential solution is to apply several alternative exposure models simultaneously, with each model assuming a different exposure-risk association, and then combine the model results.

METHODS

We simulated alternative clinically plausible associations between time-varying drug exposure and the hazard of an adverse event. Prospective surveillance was conducted on the simulated data by estimating parametric and semi-parametric exposure-risk models at multiple times during follow-up. For each model separately, and using combined evidence from different subsets of models, we compared the time to signal detection.

RESULTS

Timely detection across the simulated associations was obtained by fitting a set of pharmacovigilance models. This set included alternative parametric models that assumed different exposure-risk associations and flexible models that made no assumptions regarding the form/shape of the association. Times to detection generated using a simple combination of evidence from multiple models were comparable to those observed under the ideal, but unrealistic, scenario where pharmacovigilance relied on the single 'true' model used for data generation.

CONCLUSIONS

Simulation results indicate that, if the true model is not known, an association can be detected in a more timely manner by first fitting a carefully selected set of exposure-risk models and then generating a signal as soon as any of the models considered yields a test statistic value below a predetermined testing threshold.

Antiviral Activity, Safety, and Pharmacokinetics of Bictegravir as 10-Day Monotherapy in HIV-1-Infected Adults

OBJECTIVE

To evaluate antiviral activity, safety, and pharmacokinetics of short-term monotherapy with bictegravir (BIC), a novel, potent HIV integrase strand transfer inhibitor (INSTI).

DESIGN

Phase 1b, randomized, double-blinded, adaptive, sequential cohort, placebo-controlled study.

METHODS

HIV-infected adults not taking antiretroviral therapy were randomized to receive BIC (5, 25, 50, or 100 mg) or placebo once daily for 10 days. Primary endpoint was time-weighted average change from baseline to day 11 (DAVG11) for plasma HIV-1 RNA. HIV-1 RNA, adverse events (AEs), and laboratory assessments were evaluated through day 17.

RESULTS

Twenty participants were enrolled (n = 4/group). Mean DAVG11 ranged from -0.92 to -1.61 across BIC doses versus -0.01 for placebo. Significant reductions in plasma HIV-1 RNA from baseline at day 11 were observed for all BIC doses compared with placebo (P < 0.001); mean decreases were 1.45-2.43 log10 copies/mL. Increased BIC exposures correlated with increased reduction in plasma HIV-1 RNA from baseline on day 11. Three participants on BIC (50 or 100 mg) achieved plasma HIV-1 RNA <50 copies/mL by end of study. Median Tmax ranged from 1.0 to 1.8 hours (day 1, postdose) and 1.3-2.7 hours (day 10), with median t1/2 ranging from 15.9 to 20.9 hours. No participant developed primary INSTI-R substitution through day 17. BIC was well tolerated, with no discontinuations because of adverse events.

CONCLUSIONS

BIC is a novel, potent, unboosted INSTI that demonstrated rapid, dose-dependent declines in HIV-1 RNA after 10 days of monotherapy. BIC was well tolerated, and displayed rapid absorption and a half-life supportive of once-daily therapy in HIV-infected subjects.

Cardiovascular disease in patients with HIV

With the progressive increase in life expectancy of HIV-positive patient, thanks to "highly active antiretroviral therapy" (HAART), new comorbidities, and especially cardiovascular diseases (CVDs) are emerging as an important concern. An increased risk of coronary artery disease, often in a younger age, has been observed in this population. The underlying pathophysiology is complex and partially still unclear, with the interaction of viral infection-and systemic inflammation-antiretroviral therapy and traditional risk factors. After an accurate risk stratification, primary prevention should balance the optimal HAART to suppress the virus-avoiding side-effects-the intervention on life-style and the treatment of traditional risk factors (hypertension, dyslipidemia, and diabetes). Also the management after a cardiovascular event is challenging: revascularization strategies-both percutaneous and surgical-are valuable options, keeping in mind the higher rates of recurrent events, and caution is essential to avoid drug-drug interactions. Large evidence-based data on HIV-infected patients are still lacking, and recommendations often follow those of general population. Therefore we performed a comprehensive evaluation of the literature to analyze the current knowledge on CVD's prevalence, prevention and treatment in HIV-infected patients.

Cardiovascular disease in women with HIV-1 infection

Cardiovascular disease is a leading cause of death in women, nevertheless it is often underestimated in female patients without overt risk factors. The chronic infection by Human Immunodeficiency Virus (HIV) is clearly associated, along with the use of certain antiretroviral drugs and traditional risk factors, with an increased risk of cardiovascular diseases. The aim of this manuscript is to review the epidemiology, risk factors, pathogenesis, diagnostic approach, primary and secondary prevention strategies of cardiovascular disease in HIV-negative and HIV-positive female subjects. The ultimate goal is to promote knowledge and development of specific and appropriate clinical interventions and guidelines in this group of high-risk patients, mostly in view of the expected growth of ageing females with HIV.

Skin advanced glycation end products in HIV infection are increased and predictive of development of cardiovascular events

OBJECTIVE

HIV-1 infection is associated with an increased cardiovascular disease (CVD) risk. Advanced glycation end products are formed as stable markers of glycaemic and oxidative stress. Skin autofluorescence (SAF) as marker of accumulated advanced glycation end products is increased and predictive of CVD events in diabetes mellitus, chronic kidney disease (CKD), and preexisting CVD. We determined SAF levels in HIV-1 infected patients, testing the hypothesis that SAF predicts CVD events in HIV infection.

DESIGN

Single-centre prospective cohort study.

METHODS

In 2010-2011, SAF was measured in 91 patients. Development of CVD events was monitored during a median follow-up of 4.8 years. SAF values of the patients were expressed as a ratio (rSAF) to expected SAF levels in age-matched healthy volunteers.

RESULTS

Seventy-nine men and 12 women were included, mean age 47 years; 81 patients were on combination antiretroviral therapy. With a mean rSAF of 1.155, SAF levels in patients were 15.5% higher than predicted for their age (95% confidence interval, 10.0-20.0; P < 0.001). In multivariate regression analysis, rSAF was associated with nadir CD4 cell count less than 200 cells/μl (β -0.274; P = 0.01), smoking (β 0.240; P = 0.03), and men who have sex with men (MSM) (β 0.202; P = 0.07). CVD events occurred in six patients (7%). In Cox regression analysis including age, SAF, smoking, diabetes, hypertension and CKD, SAF (P = 0.01), and (Wet Medisch-wetenschappelijk Onderzoek met mensen; WMO) CKD (P = 0.03) remained as independent predictors of CVD events.

CONCLUSION

SAF is increased in HIV-infected patients, and related with smoking, low nadir CD4 cell count, and MSM. Larger studies are needed to confirm whether SAF is an independent predictor of CVD events.

The role of tenofovir alafenamide in future HIV management

HIV infection has become a chronic condition rather than an acute life-threatening disease in developed countries, thanks to consistent innovation and evolution of effective interventions. This has altered HIV management and created new challenges. People living with HIV (PLWHIV) are living longer and so encounter comorbidities linked not only with their disease, but also with ageing, lifestyle and chronic exposure to antiretroviral therapy (ART). Although longevity, viral suppression and the prevention of viral transmission remain key goals, more needs to be achieved to encompass the vision of attaining an optimum level of overall health. Treatment choices and management practices should ensure patients' long-term health with minimal comorbidity. Treatments that balance optimal efficacy with the potential for improved long-term safety are needed for all patients. In this review, we consider the evolution and development of tenofovir alafenamide (TAF), a novel prodrug of tenofovir which offers high antiviral efficacy at doses over ten times lower than that of tenofovir disoproxil fumarate (TDF). Emerging clinical data suggest that elvitegravir, cobicistat, emtricitabine and TAF (E/C/F/TAF) as a single-tablet regimen offers highly effective viral suppression in treatment-naïve and treatment-experienced patients with an improved renal and bone safety profile compared with TDF, this having been demonstrated in diverse groups including patients with existing renal impairment and adolescents. The profile of TAF identifies it as an agent with a promising role within future ART regimens that aim to deliver the vision of undetectable viral load, while requiring less monitoring and having a safety profile designed to minimize comorbid risks while supporting good long-term health.

Modifying Antiretroviral Therapy in Virologically Suppressed HIV-1-Infected Patients

HIV-1-infected patients with suppressed plasma viral loads often require changes to their antiretroviral (ARV) therapy to manage drug toxicity and intolerance, to improve adherence, and to avoid drug interactions. In patients who have never experienced virologic failure while receiving ARV therapy and who have no evidence of drug resistance, switching to any of the acceptable US Department of Health and Human Services first-line therapies is expected to maintain virologic suppression. However, in virologically suppressed patients with a history of virologic failure or drug resistance, it can be more challenging to change therapy while still maintaining virologic suppression. In these patients, it may be difficult to know whether the discontinuation of one of the ARVs in a suppressive regimen constitutes the removal of a key regimen component that will not be adequately supplanted by one or more substituted ARVs. In this article, we review many of the clinical scenarios requiring ARV therapy modification in patients with stable virologic suppression and outline the strategies for modifying therapy while maintaining long-term virologic suppression.

Telmisartan increases vascular reparative capacity in older HIV-infected adults: a pilot study

BACKGROUND

Endothelial progenitor cells (EPCs) are bone marrow-derived cells that contribute to vascular repair. EPCs may be reduced in HIV-infected (HIV+) persons, contributing to cardiovascular disease (CVD). Telmisartan is an angiotensin receptor blocker that increases EPCs in HIV-uninfected adults.

OBJECTIVE

To assess telmisartan's effects on EPC number and immunophenotype in older HIV + adults at risk for CVD.

METHODS

HIV + persons ≥50 years old with HIV-1 RNA < 50 copies/mL on suppressive antiretroviral therapy and ≥1 CVD risk factor participated in a prospective, open-label, pilot study of oral telmisartan 80 mg daily for 12 weeks. Using CD34 and CD133 as markers of early maturity and KDR as a marker of endothelial lineage commitment, EPCs were quantified via flow cytometry and defined as viable CD3^-/CD33^-/CD19^-/glycophorin^- cells of four immunophenotypes: CD133⁺/KDR⁺, CD34⁺/KDR⁺, CD34⁺/CD133⁺, or CD34⁺/KDR⁺/CD133⁺. The primary endpoint was a 12-week change in EPC subsets (NCT01578772).

RESULTS

Seventeen participants (88% men, median age 60 years and peripheral CD4⁺ T lymphocyte count 625 cells/mm³) enrolled and completed the study. After 6 and 12 weeks of telmisartan, frequencies of all EPC immunophenotypes were higher than baseline (all p < 0.10 except week 12 CD133⁺/KDR⁺ EPC, p = 0.13). Participants with lower baseline EPC levels had the largest gains. Additionally, the percentage of CD34⁺ cells with endothelial commitment (KDR⁺) increased.

CONCLUSIONS

Our data suggest that telmisartan use is associated with an increase in circulating EPCs in older HIV + individuals with CVD risk factors. Further controlled studies are needed to assess whether EPC increases translate to a reduction in CVD risk in this population.