P eople with HIV infection now live longer and increasingly experience age-related diseases such as coronary artery disease. Studies from North America and Europe showed a greater myocardial infarction risk ratio varying from 1.5 to 2.1 in people living with HIV (PLWH) compared with the general population (1-3). Other than age, overrepresentation of traditional cardiovascular risk factors such as smoking, dyslipidemia, hypertension, and diabetes (1,4) probably also contributes to the increased incidence of cardiovascular disease in PLWH, although this increased incidence persists after adjustment for these risk factors (1,2). An impact of antiretroviral therapy on coronary artery disease has been discussed in multiple studies (5,6). Mechanisms such as inflammation and immune dysfunction seem to have a role along the pathways to this higher risk of cardiovascular disease (7,8).Coronary CT angiography is a noninvasive imaging option of choice for the characterization, quantification, and monitoring of coronary HIV-related atherosclerosis in clinical studies and may provide robust anatomic substrates suitable for correlative assessment in mechanistic studies. Controversial findings exist regarding the higher rates of noncalcified coronary plaque in PLWH compared with healthy volunteers without HIV (9-13). In our prospective study nested in a large cohort, we aimed to compare the burden and CT characteristics of subclinical coronary atherosclerotic plaque in asymptomatic PLWH without known cardiovascular disease compared with healthy volunteers without HIV. We hypothesized Background: People living with HIV (PLWH) have a higher risk of myocardial infarction. Coronary atherosclerotic plaque CT characterization helps to predict cardiovascular risk.Purpose: To measure CT characteristics of coronary plaque in PLWH without known cardiovascular disease and healthy volunteers without HIV. Materials and Methods:In this prospective study, noncontrast CT (all participants, n = 265) was used for coronary artery calcium (CAC) scoring in asymptomatic PLWH and healthy volunteers without HIV, without known cardiovascular disease, from 2012 to 2019. At coronary CT angiography (n = 233), prevalence, frequency, and volume of calcified, mixed, and noncalcified plaque were measured. Poisson regressions were used with adjustment for cardiovascular risk factors.Results: There were 181 PLWH (mean age, 56 years 6 7; 167 men) and 84 healthy volunteers (mean age, 57 years 6 8; 65 men) evaluated by using noncontrast CT. CT angiography was performed in 155 PLWH and 78 healthy volunteers. Median 10-year Framingham risk score was not different between PLWH and healthy volunteers (10% vs 9%, respectively;

Despite the success of antiretroviral therapy (ART), people living with HIV (PLWH) are still at higher risk for cardiovascular diseases (CVDs) that are mediated by chronic inflammation. Identification of novel inflammatory mediators with the inherent potential to be used as CVD biomarkers and also as therapeutic targets is critically needed for better risk stratification and disease management in PLWH. Here, we investigated the expression and potential role of the multi-isoform proinflammatory cytokine IL-32 in subclinical atherosclerosis in PLWH (n=49 with subclinical atherosclerosis and n=30 without) and HIV- controls (n=25 with subclinical atherosclerosis and n=24 without). While expression of all tested IL-32 isoforms (α, β, γ, D, ϵ, and θ) was significantly higher in peripheral blood from PLWH compared to HIV- controls, IL-32D and IL-32θ isoforms were further upregulated in HIV+ individuals with coronary artery atherosclerosis compared to their counterparts without. Upregulation of these two isoforms was associated with increased plasma levels of IL-18 and IL-1β and downregulation of the atheroprotective protein TRAIL, which together composed a unique atherosclerotic inflammatory signature specific for PLWH compared to HIV- controls. Logistic regression analysis demonstrated that modulation of these inflammatory variables was independent of age, smoking, and statin treatment. Furthermore, our in vitro functional data linked IL-32 to macrophage activation and production of IL-18 and downregulation of TRAIL, a mechanism previously shown to be associated with impaired cholesterol metabolism and atherosclerosis. Finally, increased expression of IL-32 isoforms in PLWH with subclinical atherosclerosis was associated with altered gut microbiome (increased pathogenic bacteria; Rothia and Eggerthella species) and lower abundance of the gut metabolite short-chain fatty acid (SCFA) caproic acid, measured in fecal samples from the study participants. Importantly, caproic acid diminished the production of IL-32, IL-18, and IL-1β in human PBMCs in response to bacterial LPS stimulation. In conclusion, our studies identified an HIV-specific atherosclerotic inflammatory signature including specific IL-32 isoforms, which is regulated by the SCFA caproic acid and that may lead to new potential therapies to prevent CVD in ART-treated PLWH.

Background Despite antiretroviral therapy (ART), people living with HIV (PLWH) have increased risk of inflammatory comorbidities, including cardiovascular diseases. Gut epithelial damage, and translocation of bacterial lipopolysaccharide (LPS) or fungal β-D-Glucan (BDG) drive inflammation in ART-treated PLWH. Herein, we investigated whether markers of gut damage and microbial translocation were associated with cardiovascular risk in asymptomatic ART-treated PLWH. Methods We cross-sectionally analyzed plasma from 93 ART-treated PLWH and 52 uninfected controls older than 40 years of age from the Canadian HIV and Aging Cohort. Participants were cardiovascular disease free and underwent a cardiac computed tomography to measure total coronary atherosclerotic plaque volume (TPV). Levels of bacterial LPS, and gut damage markers REG3α and I-FABP were measured by ELISA. Fungal BDG levels were analyzed using the Fungitell ® assay. Results BDG levels but not LPS were significantly elevated in ART-treated PLWH with coronary artery plaque (p=0.0007). Moreover, BDG but not LPS levels correlated with TPV (r=0.25, p=0.01). I-FABP but not REG3α levels correlated with TPV (r=0.23, p=0.03). However, BDG and LPS levels were not elevated in uninfected controls with plaque. In multivariable models, elevated BDG levels were independently associated with the presence of coronary atherosclerosis in PLWH but not in uninfected controls. Conclusion Translocation of fungal BDG was associated with coronary atherosclerosis assessed by CT-scan imaging in ART-treated PLWH, suggesting a HIV-specific pathway leading to cardiovascular disease. Further investigation is needed to appraise causality of this association. Translocation of fungal products may represent a therapeutic target to prevent cardiovascular disease in ART-treated PLWH.

a,b,d , for the investigators of the Canadian HIV and Aging Cohort Study Objectives: People with HIV are exposed to a higher risk of coronary artery disease (CAD) compared with the general population. Epicardial fat may play a unique role in promoting coronary atherosclerosis. We measured epicardial fat in participants living with HIV and controls and investigated its association with coronary plaque volume and low attenuation plaque, a marker of plaque vulnerability.Design: This is a cross-sectional study, nested in the Canadian HIV and Aging Cohort Study, a large prospective cohort actively following participants with HIV and controls. Participants with low/intermediate cardiovascular risk without symptoms/history of CAD were invited to undergo cardiac computed tomography (CT).Methods: Volume of epicardial fat, coronary plaque and low attenuation component of the plaque were measured. Association between epicardial fat, coronary plaque volume and low attenuation component was tested using adjusted regression analysis.Results: A total of 169 participants with HIV and 81 controls underwent cardiac CT. Participants with HIV had a greater epicardial fat volume compared with controls (P ¼ 0.019). In participants with HIV, epicardial fat volume was positively associated with duration of nonnucleoside reverse transcriptase inhibitors (NNRTI) (b¼2.19, P ¼ 0.004). After adjustment for cardiovascular risk factors, epicardial fat volume was positively associated to noncalcified plaque volume [odds ratio (OR) ¼ 1.09, P ¼ 0.028] and to the low-attenuation plaque component portion (b¼0.38, P ¼ 0.026). Conclusion:The association of epicardial fat volume to noncalcified plaque volume and to low attenuation component plaque may suggest a potential mechanism by which epicardial fat could be a silent driver of CAD in the HIV population.

ObjectiveTo assess computed tomography pulmonary angiography (CTPA) positive yield rate for pulmonary embolism (PE) in a Canadian academic tertiary center.ResultsThis one-center retrospective cross-sectional study includes from 5565 (model 1) to 5296 (model 2) patients that were evaluated for suspected PE in 2015, among which 1331 (23.9% (model 1) to 25.1% (model 2)) underwent CTPA. Mean age of CTPA patients was 60.2 ± 16.6 years, of which 575 were males (43.2%). Two hundred eleven CTPA examinations were positive for PE, giving a CTPA positive yield rate of 15.9% (95% CI (13.93–17.87)). One hundred and thirteen (8.1%) CTPA were considered indeterminate, and eleven were considered nondiagnostic (0.8%). Among the 211 CTPA positive for PE, 67 (32%) were proximal emboli, 98 (47%) were segmental emboli and 44 (21%%) were subsegmental emboli. In conclusion, in this retrospective study done in a Canadian academic tertiary center, we report a positive rate of 15.9% for PE detection with CTPA, which is above the generally accepted lower threshold of 10% for the yield of CTPA.