Comparison of the Peripheral Reactive Hyperemia Index with Myocardial Perfusion Reserve by 82Rb PET/CT in HIV-Infected Patients

Coronary microvascular dysfunction is an independent predictor of developing cancer in patients with non-obstructive coronary artery disease

AIMS

Cardiovascular disease and cancer share common pathogenesis and risk factors. Coronary microvascular dysfunction (CMD), reflecting impaired coronary microvascular dilation in response to stress, is related to a higher risk of major cardiovascular events; however, its association with cancer has not been explored.

METHODS AND RESULTS

A retrospective study on 1042 patients with non-obstructive coronary artery diseases (NOCADs) was performed. Data regarding demographic, clinical history, diagnostic coronary reactivity test, and cancer occurrence were collected. Coronary microvascular dysfunction was defined as coronary flow reserve (the ratio of hyperaemic blood flow to resting blood flow) ≤2.5. Thirty-four per cent had CMD (67.4% female and the average age was 52.4 ± 12.2 years). Of 917 patients with no history of cancer, 15.5% developed cancer during follow-up [median of 9 (4, 16) years]. Kaplan-Meier analysis showed that CMD patients had lower cancer-free survival compared with those without CMD (log-rank P = 0.005). Cox proportional hazard analyses showed that after adjusting for age, sex, hypertension, diabetes, smoking, and glomerular filtration rate, CMD is independently associated with cancer [hazard ratio, 1.4; 95% confidence interval (CI), 1.09-2.04; P = 0.04]. The rate of major adverse cardiovascular events (MACE) was significantly higher in CMD patients compared with that in non-CMD patients who had a previous history of cancer [odds ratio (OR), 2.5; 95% CI, 1-6.2; P = 0.04] and those with no history of cancer (OR, 1.4; 95% CI, 1.01-1.9; P = 0.044).

CONCLUSION

Coronary microvascular dysfunction is associated with cancer incidence in patients presenting with NOCADs. This study emphasizes follow-up in patients with CMD to evaluate the risk of MACE as well as potential malignant diseases.

HIV and race are independently associated with endothelial dysfunction

OBJECTIVE

Evaluating the vascular function in HIV-infected compared with HIV uninfected with assessment of body composition, inflammation, and gut integrity markers.

DESIGN

A noninvasive test that measures the endothelial function.

METHODS

We included participants at least 18 years old, with peripheral arterial tonometry testing (EndoPAT2000) between 2014 and 2022. Persons with HIV (PWH) had documented infection, a stable ART regimen, and a viral load less than 400 copies/ml. We measured the vessel's function with the reactive hyperemia index (RHI) (normal >1.67) and Augmentation Index. Lower Augmentation Index reflect better arterial elasticity. We assessed markers of systemic inflammation, immune activation, and gut integrity. We used linear mixed models to estimate endothelial dysfunction with a significant P value less than 0.05.

RESULTS

Overall, 511 participants (296 HIV-infected; 215 HIV-uninfected controls) were included. Estimated RHI among PWH was 13% lower (P = 0.01) compared with persons without HIV. In nonwhite race, the estimated RHI was 9% lower (P = 0.001) than white race. For every 1% increase in BMI, we would expect RHI to increase 0.17% (P = 0.01). At the time of EndoPAT, the estimated RHI was 8% lower (P = 0.04) among protease inhibitor users compared with PWH who were not taking protease inhibitors. The estimated odds of abnormal RHI ≤1.67) is 1.56 times greater [95% confidence interval (CI) 1.05-2.31] in nonwhite race compared with white race, independent of HIV status [OR = 1.4 (95% CI 0.94-2.13)]. There was not enough evidence to suggest that inflammation, gut, or monocyte markers, current or nadir CD4+ cell count, or duration of HIV were associated with endothelial dysfunction.

CONCLUSION

HIV, nonwhite race, and protease inhibitor use are independently associated with endothelial dysfunction.

Association of Endothelial Dysfunction and Antiretroviral Therapy in Early HIV Infection

IMPORTANCE

Human immunodeficiency virus (HIV) infection is associated with increased cardiovascular disease (CVD) events. Endothelial dysfunction (EDF) is involved in CVD pathogenesis; however, EDF onset after HIV acquisition and the potential for reversibility with antiretroviral therapy (ART) have not been evaluated to date.

OBJECTIVE

To evaluate endothelial function with noninvasive reactive hyperemia index (RHI) in patients with early HIV infection at baseline and after ART initiation.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study in which 61 members of the United States Air Force diagnosed with HIV infection from September 1, 2015, through September 30, 2017, were evaluated for baseline EDF. Natural log-transformed RHI values (lnRHI) of less than 0.51 and at least 0.51 were defined as abnormal and normal, respectively. The RHI interval changes were evaluated in a subgroup of 40 patients. Data were analyzed from September 30, 2017, through January 30, 2018.

EXPOSURE

Early HIV infection.

MAIN OUTCOMES AND MEASURES

Baseline EDF at HIV diagnosis and interval changes associated with ART initiation.

RESULTS

The 61 patients included in the analysis were predominantly male (58 [95%]) and mostly African American (35 [57%]), with a mean (SD) age of 28.1 (6.7) years at HIV diagnosis. Median time from estimated date of HIV seroconversion to RHI assessment was 10.6 months (interquartile range [IQR], 5.1-13.2 months), and the median CD4 lymphocyte count was 552/μL (IQR, 449/μL-674/μL). Patients had a mean (SD) body mass index of 26.2 (4.0), median (IQR) low-density lipoprotein cholesterol level of 97 (80-126) mg/dL, median (IQR) total cholesterol level of 163 (146-195) mg/dL, and no diabetes diagnoses. Overall mean (SD) lnRHI was 0.70 (0.29) at HIV diagnosis. Baseline RHI was normal in 47 patients (77%; mean [SD] lnRHI, 0.82 [0.20]) and was abnormal in 14 patients (23%; mean [SD] lnRHI, 0.30 [0.18]). Age (per 10-year increase) was not associated with an abnormal lnRHI (odds ratio, 2.15; 95% CI, 0.89-5.19; P = .09). Of the 41 patients with follow-up RHI assessments, 40 started ART immediately and repeated the RHI assessments at a median (IQR) of 6.4 (6.0-7.8) months. Use of ART was associated with an overall significan increase in mean (SD) lnRHI (0.13 [0.33]; P = .02). A greater increase in mean (SD) lnRHI was associated with abnormal (n = 11) compared with normal (n = 29) lnRHI at HIV diagnosis (0.33 [0.34]; P = .01 vs 0.04 [0.30]; P = .38). Among those with abnormal baseline lnRHI, 8 (73%) showed improved endothelial function after ART. The patient who declined ART converted from having a normal lnRHI (0.60) to an abnormal lnRHI (0.11) lnRHI after 8.3 months.

CONCLUSIONS AND RELEVANCE

In this study, EDF was common in early HIV infection, with associated reversal in most patients taking ART. Results suggest that persistent EDF and CVD complications may be associated with delayed ART. Further studies are necessary to define the role of noninvasive endothelial function testing in patients with HIV infection.

Seeing Is Believing: Nuclear Imaging of HIV Persistence

A major obstacle to HIV eradication is the presence of infected cells that persist despite suppressive antiretroviral therapy (ART). HIV largely resides outside of the peripheral circulation, and thus, numerous anatomical and lymphoid compartments that have the capacity to harbor HIV are inaccessible to routine sampling. As a result, there is a limited understanding of the tissue burden of HIV infection or anatomical distribution of HIV transcriptional and translational activity. Novel, non-invasive, in vivo methods are urgently needed to address this fundamental gap in knowledge. In this review, we discuss past and current nuclear imaging approaches that have been applied to HIV infection with an emphasis on current strategies to implement positron emission tomography (PET)-based imaging to directly visualize and characterize whole-body HIV burden. These imaging approaches have various limitations, such as the potential for limited PET sensitivity and specificity in the setting of ART suppression or low viral burden. However, recent advances in high-sensitivity, total-body PET imaging platforms and development of new radiotracer technologies that may enhance anatomical penetration of target-specific tracer molecules are discussed. Potential strategies to image non-viral markers of HIV tissue burden or focal immune perturbation are also addressed. Overall, emerging nuclear imaging techniques and platforms may play an important role in the development of novel therapeutic and HIV reservoir eradication strategies.