Predictive value of telomere length on outcome following acute myocardial infarction: evidence for contrasting effects of vascular vs. blood oxidative stress

Analysis of the perivascular fat attenuation index and quantitative plaque parameters in relation to haemodynamically impaired myocardial ischaemia

To investigate the correlation between quantitative plaque parameters, the perivascular fat attenuation index, and myocardial ischaemia caused by haemodynamic impairment. Patients with stable angina who had invasive flow reserve fraction (FFR) assessment and coronary artery computed tomography (CT) angiography were retrospectively enrolled. A total of 138 patients were included in this study, which were categorized into the FFR < 0.75 group (n = 43), 0.75 ≤ FFR ≤ 0.8 group (n = 37), and FFR > 0.8 group (n = 58), depending on the range of FFR values. The perivascular FAI and CTA-derived parameters, including plaque length (PL), total plaque volume (TPV), minimum lumen area (MLA), and narrowest degree (ND), were recorded for the lesions. An FFR < 0.75 was defined as myocardial-specific ischaemia. The relationships between myocardial ischaemia and parameters such as the PL, TPV, MLA, ND, and FAI were analysed using a logistic regression model and receiver operating characteristic (ROC) curves to compare the diagnostic accuracy of various indicators for myocardial ischaemia. The PL, TPV, ND, and FAI were greater in the FFR < 0.75 group than in the grey area group and the FFR > 0.80 group (all p < 0.05). The MLA in the FFR < 0.75 group was lower than that in the grey area group and the FFR > 0.80 group (both P < 0.05). There were no significant differences in the PL, TPV, or ND between the grey area and the FFR > 0.80 group, but there was a significant difference in the FAI. The coronary artery lesions with FFRs ≤ 0.75 had the greatest FAI values. Multivariate analysis revealed that the perivascular FAI and PL density are significant predictors of myocardial ischaemia. The FAI has some predictive value for myocardial ischaemia (AUC = 0.781). After building a combination model using the FAI and plaque length, the predictive power increased (AUC, 0.781 vs. 0.918), and the change was statistically significant (P < 0.001). The combined model of PL + FAI demonstrated great diagnostic efficacy in identifying myocardial ischaemia caused by haemodynamic impairment; the lower the FFR was, the greater the FAI. Thus, the PL + FAI could be a combined measure to securely rule out myocardial ischaemia.

Progress in Understanding Oxidative Stress, Aging, and Aging-Related Diseases

Under normal physiological conditions, reactive oxygen species (ROS) are produced through redox reactions as byproducts of respiratory and metabolic activities. However, due to various endogenous and exogenous factors, the body may produce excessive ROS, which leads to oxidative stress (OS). Numerous studies have shown that OS causes a variety of pathological changes in cells, including mitochondrial dysfunction, DNA damage, telomere shortening, lipid peroxidation, and protein oxidative modification, all of which can trigger apoptosis and senescence. OS also induces a variety of aging-related diseases, such as retinal disease, neurodegenerative disease, osteoarthritis, cardiovascular diseases, cancer, ovarian disease, and prostate disease. In this review, we aim to introduce the multiple internal and external triggers that mediate ROS levels in rodents and humans as well as the relationship between OS, aging, and aging-related diseases. Finally, we present a statistical analysis of effective antioxidant measures currently being developed and applied in the field of aging research.

17-year follow-up of association between telomere length and all-cause mortality, cardiovascular mortality in individuals with metabolic syndrome: results from the NHANES database prospective cohort study

BACKGROUND

The relationship between leukocyte telomere length (LTL) and mortality risk in individuals with metabolic syndrome (MetS) remains poorly understood. This study aimed to investigate the association between telomere length and long-term all-cause mortality, and cardiovascular disease (CVD) mortality, in individuals with MetS in the United States.

METHODS

A total of 1980 participants with MetS aged 18 years or older from the National Health and Nutrition Examination Survey (NHANES) prospective cohort study (1999-2002) were included in this cohort study. Medical records review was used to identify the cause of deaths as of December 2018. We employed Kaplan-Meier curves, fitted curves, and Cox proportional hazards regression models to estimate hazard ratios (HRs) for all-cause and CVD mortality, stratified by tertiles of LTL.

RESULTS

Over a median follow-up of 17.75 years of participants with metabolic syndrome, 819 deaths occurred, including 231 cardiovascular deaths. After adjusting for multiple covariates, participants with shorter telomere length had a significantly higher risk of all-cause mortality (HR, 1.33; 95% CI, 1.11-1.6) and CVD mortality (HR, 1.36; 95% CI, 0.96-1.93) compared with those in the highest tertile of telomere length. All-cause mortality (P < 0.001) and cardiovascular disease mortality (P = 0.028) followed a similar pattern across tertiles of telomere length.

CONCLUSION

In individuals with MetS, shorter telomere length is associated with increased risks of death from cardiovascular disease and all causes. The underlying mechanisms and clinical implications of these findings require additional investigation.

Hepatic steatosis evidenced by computed tomography in patients undergoing primary percutaneous coronary intervention for acute myocardial infarction

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and acute myocardial infarction (AMI) have common pathological links. This study investigates the prognostic impact of NAFLD assessed as hepatic steatosis (HS) by computed tomography (CT) in AMI patients and explores the mechanistic role of NAFLD in cardiovascular (CV) events using coronary angioscopy (CAS).

METHODS

We retrospectively examined 342 AMI patients who underwent CT followed by primary percutaneous coronary intervention (PCI) between January 2014 and December 2019. HS was defined as a hepatic to spleen attenuation ratio of <1.0 on CT scans. Major cardiac events (MCE) included cardiac death, non-fatal myocardial infarction, target-vessel revascularization, and target-lesion revascularization.

RESULTS

HS was identified in 88 patients (26 %). Patients with HS were significantly younger, had a higher body mass index, and higher hemoglobin A1c, triglyceride, and malondialdehyde low-density lipoprotein levels (all p < 0.05). MCE occurred more frequently [27 (30.7 %) vs. 39 (15.4 %), p = 0.001] in the HS group than in the non-HS group. In the multivariate analysis, the presence of HS was an independent predictor of MCE after adjusting for metabolic risk factor and liver function markers. Among the 74 patients who underwent CAS for a median of 15 days after primary PCI, 51 (69 %) had intrastent thrombus, which was strongly associated with the presence of HS [18 (35 %) vs. 1 (4 %), p = 0.005].

CONCLUSIONS

AMI patients with NAFLD detected by CT often had CAS-derived intrastent thrombi and were at a high risk for CV events. Therefore, these patients should be carefully monitored.

Association between telomere length and intima-media thickness of both common carotid arteries in patients with coronary heart disease: From the CORDIOPREV randomized controlled trial

BACKGROUND AND AIMS

A critical telomere length (TL) is associated with cardiovascular mortality. Dietary habits have been demonstrated to affect cardiovascular risk. However, it remains unclear how exactly TL determines the response to specific dietary approaches in the reduction of arterial injury. We aimed to evaluate whether TL was associated with the progression of arterial injury (assessed by intima-media thickness of both common carotid arteries: IMT-CC), after long-term consumption of two healthy dietary models in patients with coronary heart disease (CHD).

METHODS

From the 1002 CHD patients of the CORDIOPREV study, 903 completed IMT-CC and TL evaluation at baseline and were randomized to follow a Mediterranean diet or a low-fat diet for 5 years.

RESULTS

Patients at risk of short TL (TL < 20th percentile) presented an elevated IMT-CC, (0.79 ± 0.17 vs patients at non-risk 0.74 ± 0.17 p < 0.001). TL and IMT-CC showed an inverse association (β = -0.035, p = 0.002). Patients who consumed a Mediterranean diet, regardless of the risk of short TL, showed a significant decrease in IMT-CC, with a higher reduction in those patients with risk of short TL (-0.03 ± 0.11, p = 0.036). TL (β = 0.019, p = 0.024), age (β = -0.001, p = 0.031), energy intake (β = -0.000, p = 0.036), use of statins (β = -0.027, p = 0.028) and allocation into the Mediterranean diet (vs low-fat diet) (β = -0.024, p = 0.003) were significant contributors to changes in IMT-CC.

CONCLUSIONS

Patients who had a reduced TL exhibited a greater decrease in IMT-CC after consuming a Mediterranean diet.

Associations between preprocedural carotid artery perivascular fat density and early in-stent restenosis after carotid artery stenting

Objectives

This study investigated the association between perivascular fat density (PFD) via preoperative computed tomographic angiography (CTA) and early in-stent restenosis (ISR) after carotid artery stenting (CAS).

Methods

We retrospectively evaluated 248 consecutive patients who had undergone initial CAS and received a preoperative cervical CTA examination between January 2019 and October 2020. The patients were categorized into two according to whether they sustained ISR during the 2 years postoperative follow-up period. Correlations between PFD and ISR were assessed, and multivariate regression for evaluating predictors of ISR was conducted. Receiver operating characteristic (ROC) curves were used to determine the cutoff value for the PFD.

Results

A total of 181 eligible patients (mean age 61.25 ± 10.35 years, 57 male) were enrolled. The ISR group had a higher proportion of closed-cell stents (48.8% versus 27.5%; p = 0.009) and a greater degree of residual stenosis (28[20,33] % versus 20[14.75,30] %; p < 0.001) than the non-ISR group. The ISR group had a higher mean HU value of PFD than the non-ISR group on the operated side (-42.26 ± 6.81 versus -59.66 ± 10.75; p < 0.001). The degree of residual stenosis (OR 1.146, 95%CI 1.071-1.226, p < 0.001) and PFD on the operated side (OR1.353, 95%CI 1.215-1.506, p < 0.001) were significantly associated with the ISR.

Conclusions

The occurrence of the early ISR after CAS is associated with a higher PFD on the operated side. The results indicate that PFD is a promising marker to predict the ISR after CAS.

Changes in Telomere Length and Indicators of Oxidative Stress in Critically Ill Mechanically Ventilated Adults - A Pilot Study

BACKGROUND

Telomeres are structures at the end of chromosomes that shorten with each cell division. The purpose of this pilot project is to report changes in telomere length (T/S ratio), indicators of oxidative stress (serum protein carbonyl, vitamin C, GSH:GSSG, and total antioxidant capacity) from Intensive Care Unit (ICU) admission to ICU discharge, and to explore their association with ICU-related morbidities among critically ill mechanically ventilated adults.

METHODS

Blood was collected from mechanically ventilated patients (n = 25) at enrollment and within 48 hours of ICU discharge. Telomere length from peripheral blood mononuclear cells (PBMCs) was determined using RTqPCR. ELISAs were used to measure indicators of oxidative stress. Descriptive analysis, paired t-tests, and Pearson's correlations were performed.

RESULTS

Mean age was 62.0 ± 12.3 years, 28.6% were male, and 76.2% were White with disease severity using APACHE III (74.6 ± 24.6) and SOFA (7.6 ± 3.2). Mean T/S ratios shortened (ICU: 0.712, post-ICU: 0.683, p < 0.001, n = 19) and serum protein carbonyl increased (ICU: 7437 nmol/mg ± 3328, post-ICU: 10,254 nmol/mg ± 3962, p < 0.005) as did the oxidative stress index (protein carbonyl/GSH:GSSG, ICU: 1049.972 ± 420.923, post-ICU: 1348.971 ± 417.175, p = 0.0104). T/S ratio was positively associated with APACHE III scores (ICU: r = 0.474, post-ICU: r = 0.628, p < 0.05).

CONCLUSIONS

Pilot findings suggest that critical illness significantly correlates with telomere attrition, perhaps due to increased oxidative stress. Future larger and longitudinal studies investigating mechanisms of telomere attrition and associations with clinical outcomes are needed to identify potential modifiable factors for subsequent intervention to improve outcomes for critically ill patients.

Assessment of myocardial bridging and the pericoronary fat attenuation index on coronary computed tomography angiography: predicting coronary artery disease risk

BACKGROUND

The fat attenuation index (FAI) is a radiological parameter that represents pericoronary adipose tissue (PCAT) inflammation, along with myocardial bridging (MB), which leads to pathological shear stress in the coronary vessels; both are associated with coronary atherosclerosis. In the present study, we assessed the predictive value of FAI values and MB parameters through coronary computed tomography angiography (CCTA) for predicting the risk of coronary atherosclerosis and vulnerable plaque in patients with MB.

METHODS

We included 428 patients who underwent CCTA and were diagnosed with MB. FAI values, MB parameters, and high-risk coronary plaque (HRP) characteristics were recorded. The subjects were classified into two groups (A and B) according to the absence or presence of coronary plaque in the segment proximal to the MB. Group B was further divided into Groups B₁ (HRP-positive) and B₂ (HRP-negative) according to the HRP characteristic classification method. The differences among the groups were analysed. Multiple logistic regression analysis was performed to determine the independent correlation between FAI values and MB parameters and coronary atherosclerosis and vulnerable plaque risk.

RESULTS

Compared to the subjects in Group A, those in Group B presented greater MB lengths, MB depths and muscle index values, more severe MB systolic stenosis and higher FAI_lesion values (all P < 0.05). In multivariate logistic analysis, age (OR 1.076, P < 0.001), MB systolic stenosis (OR 1.102, P < 0.001) and FAI_lesion values (OR 1.502, P < 0.001) were independent risk factors for the occurrence of coronary atherosclerosis. Compared to subjects in Group B₂, those in Group B₁ presented greater MB lengths and higher FAI values (both P < 0.05). However, only the FAI_lesion value was an independent factor for predicting HRP (OR 1.641, P < 0.001).

CONCLUSION

In patients with MB, MB systolic stenosis was associated with coronary plaque occurrence in the segment proximal to the MB. The FAI value was not only closely related to coronary atherosclerosis occurrence but also associated with plaque vulnerability. FAI values may provide more significant value in the prediction of coronary atherosclerosis than MB parameters in CCTA.

Telomere Length: A Cardiovascular Biomarker and a Novel Therapeutic Target

Coronary artery disease (CAD) is a multifactorial disease with a high prevalence, particularly in developing countries. Currently, the investigation of telomeres as a potential tool for the early detection of the atherosclerotic disease seems to be a promising method. Telomeres are repetitive DNA sequences located at the extremities of chromosomes that maintain genetic stability. Telomere length (TL) has been associated with several human disorders and diseases while its attrition rate varies significantly in the population. The rate of TL shortening ranges between 20 and 50 bp and is affected by factors such as the end-replication phenomenon, oxidative stress, and other DNA-damaging agents. In this review, we delve not only into the pathophysiology of TL shortening but also into its association with cardiovascular disease and the progression of atherosclerosis. We also provide current and future treatment options based on TL and telomerase function, trying to highlight the importance of these cutting-edge developments and their clinical relevance.

Expression Profiles and Functional Analysis of Plasma Exosomal Circular RNAs in Acute Myocardial Infarction

Acute myocardial infarction (AMI) is a common cardiovascular disease with high rates of morbidity and mortality globally. The dysregulation of circular RNAs (circRNAs) has been shown to be closely related to various pathological aspects of AMI. However, the function of exosomal circRNAs in AMI has yet to be investigated. The purpose of this study was to investigate the expression profiles of plasma exosomal circRNAs in AMI and explore their potential functionality. The expression profiles of plasma exosomal circRNAs in patients with AMI, stable coronary heart atherosclerotic disease (CAD), and healthy controls were obtained from a GEO expression dataset (GSE159657). We also analyzed bioinformatics functionality, potential pathways, and interaction networks related to the microRNAs associated with the differentially expressed circRNAs. A total of 253 exosomal circRNAs (184 up- and 69 down-regulated) and 182 exosomal circRNAs (94 up- and 88 down-regulated) were identified as being differentially expressed between the control group and the AMI and CAD patients, respectively. Compared with the CAD group, 231 different exosomal circRNAs (177 up- and 54 down-regulated) were identified in the AMI group. Functional analysis suggested that the parental genes of exosomal has_circ_0061776 were significantly enriched in the biological process of lysine degradation. Pathway interaction network analysis further indicated that exosomal has_circ_0061776 was associated with has-miR-133a, has-miR-214, has-miR-423, and has-miR-217 and may play a role in the pathogenesis of AMI through the MAPK signaling pathway. This study identified the differential expression and functionality of exosomal circRNAs in AMI and provided further understanding of the potential pathogenesis of an exosomal circRNA-related competing endogenous RNA (ceRNA) network in AMI.

Leukocyte Telomere Length as a Molecular Biomarker of Coronary Heart Disease

Background. This work is a review of preclinical and clinical studies of the role of telomeres and telomerase in the development and progression of coronary heart disease (CHD). Materials and methods. A search for full-text publications (articles, reviews, meta-analyses, Cochrane reviews, and clinical cases) in English and Russian was carried out in the databases PubMed, Oxford University Press, Scopus, Web of Science, Springer, and E-library electronic library using keywords and their combinations. The search depth is 11 years (2010–2021). Results. The review suggests that the relative leukocyte telomere length (LTL) is associated with the development of socially significant and widespread cardiovascular diseases such as CHD and essential hypertension. At the same time, the interests of researchers are mainly focused on the study of the relative LTL in CHD. Conclusions. Despite the scientific and clinical significance of the analyzed studies of the relative length of human LTL as a biological marker of cardiovascular diseases, their implementation in real clinical practice is difficult due to differences in the design and methodology of the analyzed studies, as well as differences in the samples by gender, age, race, and ethnicity. The authors believe that clinical studies of the role of the relative length of leukocyte telomeres in adult patients with coronary heart disease are the most promising and require large multicenter studies with a unified design and methodology.

The Perivascular Fat Attenuation Index Improves the Diagnostic Performance for Functional Coronary Stenosis

Background: Coronary computed tomography angiography (CCTA) is an established first-line test in the investigation of patients with suspected coronary artery disease (CAD), while the perivascular fat attenuation index (FAI) derived from CT seems to be a feasible and efficient tool for the identification of ischemia. The association between the FAI and lesion-specific ischemia as assessed by fractional flow reserve (FFR) remains unclear. Methods: In a total of 261 patients, 294 vessels were assessed for CCTA stenosis, vessel-specific FAI, lesion-specific FAI, and plaque characteristics. The diagnostic accuracies of each parameter and the combined approach were analyzed via the receiver operating characteristic curve (ROC) with FFR as the reference standard. The determinants of FAI were statistically analyzed. Results: The cutoff values of vessel-specific FAI and lesion-specific FAI scores calculated according to the Youden index were −70.97 and −73.95 HU, respectively. No significant differences were noted between them; however, they exhibited a strong correlation. No significant differences were noted between the area under the curve (AUC) scores of vessel-specific FAI (0.677), lesion-specific FAI (0.665), and CCTA (0.607) (p > 0.05 for all) results. The addition of two FAI measures to the CCTA showed improvements in the discrimination (AUC) and reclassification ability (relative integrated discrimination improvement (IDI) and category-free net reclassification index (NRI)), vessel-specific FAI (AUC, 0.696; NRI, 49.6%; IDI, 5.9%), and lesion-specific FAI scores (AUC, 0.676; NRI, 43.3%; IDI, 5.4%); (p < 0.01 for all). Multivariate analysis revealed that low-attenuation plaque (LAP) volume was an independent predictor of two FAI measures. Conclusion: The combined approach of adding vessel-specific FAI or lesion-specific FAI scores could improve the identification of ischemia compared with CCTA alone. The LAP volume was the independent risk factor for both tools.

Pericoronary fat attenuation index and coronary plaque quantified from coronary computed tomography angiography identify ischemia-causing lesions

BACKGROUND

The association between pericoronary fat attenuation index (FAI), plaque characteristics, and lesion-specific ischemia identified by fractional flow reserve (FFR) remains unclear.

METHODS

Coronary computed tomography angiography (CCTA) stenosis, FAI, plaque characteristics, FFR derived from computed tomography (FFR_CT) and FFR were assessed in 280 vessels of 247 patients. Stenosis ≥50% was considered obstructive. Optimal thresholds of FAI and plaque variables were defined by the area under the receiver-operating characteristics curve (AUC) analysis. Ischemia was defined by FFR ≤ 0.80.

RESULTS

FAI ≥ -71.9 HU, low-attenuation plaque (LAP) ≥ 49.62 mm³ and aggregate plaque volume (APV) ≥ 28.91% predicted ischemia independent of other plaque characteristics. The addition of FAI ≥ -71.9 HU improved discrimination (AUC, 0.720 vs. 0.674, P = 0.035) and reclassification abilities (category-free net reclassification index [NRI], 0.470, P < 0.001; relative integrated discrimination improvement [IDI], 0.047, P < 0.001) of ischemia compared with stenosis evaluation alone, with further discrimination (AUC, 0.772 vs. 0.720, P = 0.028) and reclassification abilities (NRI, 0.385, P = 0.001; relative IDI, 0.077, P < 0.001) of ischemia by adding information regarding LAP ≥49.62 mm³ + APV ≥ 28.91%. And the diagnostic performance of combination approach was comparable to that of FFR_CT alone (AUC, 0.772 vs. 0.762, P = 0.771).

CONCLUSIONS

Stenosis severity, FAI, plaque characteristics predicted lesion-specific ischemia. The combination of FAI and plaque assessment improved the discrimination of ischemia compared with stenosis assessment alone.

Screening for Regulatory Network of miRNA–Inflammation, Oxidative Stress and Prognosis-Related mRNA in Acute Myocardial Infarction: An in silico and Validation Study

Background

Acute myocardial infarction (AMI), which commonly leads to heart failure, is among the leading causes of mortality worldwide. The aim of this study was to find potential regulatory network for miRNA-inflammation, oxidative stress and prognosis-related mRNA to uncover molecular mechanisms of AMI.

Methods

The expression profiles of miRNA and mRNA in the blood samples from AMI patients were downloaded from the Gene Expression Omnibus (GEO) dataset for differential expression analysis. Weighted gene co-expression network analysis (WGCNA) was used to further identify important mRNAs. The negatively regulatory network construction of miRNA–inflammation, oxidative stress and prognosis-related mRNAs was performed, followed by protein–protein interaction (PPI) and functional analysis of mRNAs.

Results

A total of three pairs of negatively regulatory network of miRNA–inflammation and prognosis-related mRNAs (hsa-miR-636/hsa-miR-491-3p/hsa-miR-188-5p/hsa-miR-188-3p-AQP9, hsa-miR-518a-3p-C5AR1 and hsa-miR-509-3-5p/hsa-miR-127-5p-PLAUR), two pairs of negatively regulatory network of miRNA–oxidative stress and prognosis-related mRNAs (hsa-miR-604-TLR4 and hsa-miR-139-5p-CXCL1) and three pairs of negatively regulatory network of miRNA-inflammation, oxidative stress and prognosis-related mRNA (hsa-miR-634/hsa-miR-591-TLR2, hsa-miR-938-NFKBIA and hsa-miR-520h/hsa-miR-450b-3p-ADM) were identified. In the KEGG analysis, some signaling pathways were identified, such as complement and coagulation cascades, pathogenic Escherichia coli infection, chemokine signaling pathway and cytokine–cytokine receptor interaction and Toll-like receptor signaling pathway.

Conclusion

Identified negatively regulatory network of miRNA-inflammation/oxidative stress and prognosis-related mRNA may be involved in the process of AMI. Those inflammation/oxidative stress and prognosis-related mRNAs may be diagnostic and prognostic biomarkers for AMI.

Dapagliflozin Improves Cardiac Function, Remodeling, Myocardial Apoptosis, and Inflammatory Cytokines in Mice with Myocardial Infarction

Dapagliflozin (DAPA) exerts cardioprotective effects in non-diabetic patients. Nonetheless, the protective mechanism remains unknown. This study aims to evaluate the performance of DAPA on cardiac function and remodeling as well as its potential mechanism in mice with myocardial infarction (MI). Here, a MI mice model was established. One week after MI, mice were treated with saline or DAPA (1.5 mg/kg/day) for 4 weeks. At the end of this study, echocardiography was performed to assess cardiac structure and function. Myocardial apoptosis was analyzed by Western blot and immunofluorescence. Inflammatory cytokines and cardiac fibrosis were analyzed by real-time PCR and Masson's trichrome stain, respectively. Results showed that DAPA improved cardiac structure and function, attenuated cardiac fibrosis, and inhibited inflammatory cytokines and myocardial apoptosis. Moreover, the inhibition of PI3K/AKT/mTOR pathway might be related to the cardioprotective role of DAPA. These findings reveal that dapagliflozin is a potential therapeutic agent for MI patients without diabetes.

Perivascular fat imaging by computed tomography (CT): a virtual guide

Imaging in medicine has been revolutionised by technological, computational and research advances over the past decades. Computed tomography (CT), in particular, has seen rapid evolution especially in the field of cardiovascular non-invasive imaging. It is being recognised as the first-line tool for the assessment of stable and unstable disease with diagnostic, prognostic and re-stratification potential. Vascular inflammation is a key component of the atherosclerotic process and has been shown to induce molecular, transcriptional and structural changes to perivascular adipose tissue (PVAT). Being a diverse structure itself, PVAT surrounds the human vessels and is characterised by a highly rich secretome, including, amongst others, adipokines, cytokines, gaseous messengers and miRNAs It is implicated in a bidirectional interplay with the adjacent vascular wall, affecting and being affected by aspects of its biology, mainly inflammation. In this review, we discuss the current status of cardiac CT in imaging vascular inflammation through PVAT phenotyping. LINKED ARTICLES: This article is part of a themed issue on Molecular imaging - visual themed issue. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.21/issuetoc.

Association Between Carotid Artery Perivascular Fat Density and Intraplaque Hemorrhage

Objectives: Perivascular adipose tissue plays a key role in atherosclerosis, but its effects on the composition of carotid atherosclerotic plaques are unknown. This study aimed to investigate the association between inflammatory carotid artery and intraplaque hemorrhage (IPH) in the carotid artery.

Methods: This is a single-center retrospective study. Carotid inflammation was assessed by perivascular fat density (PFD) in 72 participants (mean age, 65.1 years; 56 men) who underwent both computed tomography angiography (CTA) and magnetic resonance imaging (MRI) within 2 weeks. The presence of IPH was assessed with MRI. Carotid stenosis, maximum plaque thickness, calcification, and ulceration were evaluated through CTA. The association between PFD and the occurrence of IPH was studied using generalized estimating equations analysis.

Results: Of 156 plaques, 72 plaques (46.2%) had IPH. Plaques with IPH showed higher PFD than those without [−41.4 ± 3.9 vs. −55.8 ± 6.5 Hounsfield unit (HU); p < 0.001]. After age, calcification, degree of stenosis, maximum plaque thickness, and ulceration were adjusted for, PFD (OR, 1.96; 95% CI, 1.41–2.73; p < 0.001) was found to be strongly associated with the presence of IPH.

Conclusions: A higher PFD is associated with the presence of IPH in the carotid artery. These findings may provide a novel marker to identify carotid IPH and risk stratification.

Comparison of the choroidal structural components and choroidal vascularity index between patients with obstructive sleep apnea syndrome and healthy controls

AIM

To compare the choroidal structural components and choroidal vascularity index (CVI) between patients with obstructive sleep apnea syndrome (OSAS) and healthy controls.

METHODS

The choroidal images of the eyes of patients with OSAS and healthy controls, which were obtained by using enhanced depth imaging optical coherence tomography (EDI-OCT), were binarized into luminal area (LA) and stromal area (SA) using the ImageJ software. CVI was calculated as the ratio of LA to the total choroid area (TCA). The CVI, LA, SA, and TCA measurements were compared between the groups.

RESULTS

Seventy-one eyes of 57 patients, 33 eyes of 27 patients with OSAS and 38 eyes of 30 healthy individuals, were included. The mean age of all patients was 46.77±9.75 (range, 30-67) years. There was no statistically significant difference for age, sex, axial length (AL) or the side of the eyes between the groups (p>0.05). The mean body mass index (BMI) of the patients was significantly higher in the OSAS group (p<0.05). The mean CVI value was 68.33±1.81% in the OSAS group and 69.21±1.27% in the control group (p<0.05). There was no statistically significant difference for the mean values of LA, SA, and TCA between the groups (p>0.05). No significant correlation was found between the polysomnography test results and the choroidal measurements (p>0.05).

CONCLUSION

In our study, CVI was found to be lower in patients with OSAS than in the healthy controls. Further studies with larger sample sizes are required to evaluate the role of CVI in OSAS.

The role and mechanism of hyperoside against myocardial infarction in mice by regulating autophagy via NLRP1 inflammation pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Hypericum are widely distributed in China. Hypericum perforatum L. (genus Hypericum, family Hypericaceae) has a long history as a traditional Chinese medicine, which was traditionally used for the treatment of emotional distress, cardiothoracic depression, and acute mastitis. Hyperoside (Hyp) extracted from Hypericum perforatum L. has been affirmed to exert therapeutic effects on cardiovascular diseases, with widespread existence in plants of genus Hypericum. Hyp could also be extracted from Crataegus pinnatifida Bunge (genus Crataegus pinnatifida Bunge, family Rosaceae), another traditional Chinese medicine that traditionally prevented and treated heart disease in China. The cardioprotection and mechanism of Hyp comprise anti-inflammation, anti-fibrosis, activation of autophagy, and reversal of cardiac remodeling.

AIM OF THE STUDY

This study aimed to explore the Hyp effect against MI and its underlying mechanism.

MATERIALS AND METHODS

The MI model was constructed in the KM mice via a ligating surgery of the left anterior descending (LAD) coronary artery. Subsequently, the mice were divided into following seven groups: Sham group, MI group, MI + Hyp 9 mg/kg group, MI + Hyp18 mg/kg group, MI + Hyp36 mg/kg group, MI + Fosinopril group, and MI + Hyp-36 mg/kg+3-MA group. Each group was treated with Hyp in different concentrations or positive medicine for two weeks except for the sham group. After two weeks, we examined the cardiac function, electrocardiogram (ECG), myocardial hypertrophy in the non-infarct area, collagen volume fraction (CVF), perivascular collagen area (PVCA) in the infarct area, and several serum cytokines. Autophagy and inflammation in cardiomyocytes were assessed via measuring autophagy-associated proteins and NLRP1 inflammasome pathway related proteins.

RESULTS

Hyp reversed LV remodeling and adverse ECG changes through reducing CVF and myocardial hypertrophy. Additionally, Hyp treatment could reduce inflammation levels in cardiomyocytes, compared with those in MI group. Moreover, NLRP1inflammation pathway was activated after MI. Up-regulation of autophagic flux suppressed NLRP1 inflammation pathway after Hyp treatment. However, co-treatment with 3-MA abrogated above effects of Hyp.

CONCLUSIONS

Hyp had obvious protective effect on heart injury in MI mice. Echocanrdiographic and histological measurements demonstrated that Hyp treatment improved cardiac function, and ameliorated myocardial hypertrophy and fibrinogen deposition after MI. The partial mechanism is that Hyp could up-regulate autophagy after MI. Furthermore, the promotion of autophagic flux would suppress NLRP1 inflammation pathway induced by MI.

Growth differentiation factor 11 attenuates cardiac ischemia reperfusion injury via enhancing mitochondrial biogenesis and telomerase activity

It has been reported that growth differentiation factor 11 (GDF11) protects against myocardial ischemia/reperfusion (IR) injury, but the underlying mechanisms have not been fully clarified. Considering that GDF11 plays a role in the aging/rejuvenation process and that aging is associated with telomere shortening and cardiac dysfunction, we hypothesized that GDF11 might protect against IR injury by activating telomerase. Human plasma GDF11 levels were significantly lower in acute coronary syndrome patients than in chronic coronary syndrome patients. IR mice with myocardial overexpression GDF11 (oe-GDF11) exhibited a significantly smaller myocardial infarct size, less cardiac remodeling and dysfunction, fewer apoptotic cardiomyocytes, higher telomerase activity, longer telomeres, and higher ATP generation than IR mice treated with an adenovirus carrying a negative control plasmid. Furthermore, mitochondrial biogenesis-related proteins and some antiapoptotic proteins were significantly upregulated by oe-GDF11. These cardioprotective effects of oe-GDF11 were significantly antagonized by BIBR1532, a specific telomerase inhibitor. Similar effects of oe-GDF11 on apoptosis and mitochondrial energy biogenesis were observed in cultured neonatal rat cardiomyocytes, whereas GDF11 silencing elicited the opposite effects to oe-GDF11 in mice. We concluded that telomerase activation by GDF11 contributes to the alleviation of myocardial IR injury through enhancing mitochondrial biogenesis and suppressing cardiomyocyte apoptosis.

Telomere Length and Oxidative Stress in Patients with ST-Segment Elevation and Non-ST-Segment Elevation Myocardial Infarction

PURPOSE

The telomere length is shown to act as a biomarker, especially for biological aging and cardiovascular diseases, and it is also suggested that with this correlation, increased exposure to the oxidative stress accelerates the vascular aging process. Therefore, this study aims to understand the correlation between the plasma oxidative stress index (OSI) status and leukocyte telomere length (LTL) and cardiologic parameters between the ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) groups.

METHOD

One hundred one newly diagnosed patients with STEMI (n = 55) and NSTEMI (n = 46) were included in the study, along with 100 healthy controls who matched the patients in terms of age and gender. Plasma total antioxidant status (TAS), total oxidant status (TOS), and LTL were measured.

RESULTS

When LTL, TAS, TOS, and OSI values were evaluated between the patient and control group, OSI (p = 0.000) and LTL (p = 0.05) values were statistically significant in the patient group compared to the control group. Evaluation was conducted to understand whether there is a difference between the STEMI and NSTEMI groups. The plasma OSI (p = 0.007) and LTL (p = 0.05) were found to be significantly lower in STEMI patients. However, LTL and OSI results were not statistically significant in NSTEMI patients.

CONCLUSION

This is the first study evaluating telomere length and oxidative stress in STEMI and NSTEMI patients in Turkey. Our results support the existence of short telomere length in STEMI patients. Future studies on telomere length and oxidative stress will support the importance of our findings.

Imaging of the Pericoronary Adipose Tissue (PCAT) Using Cardiac Computed Tomography: Modern Clinical Implications

Modern coronary computed tomography angiography (CTA) is the gold standard to visualize the epicardial adipose tissue (EAT) and pericoronary adipose tissue (PCAT). The EAT is a metabolic active fat depot enclosed by the visceral pericardium and surrounds the coronary arteries. In disease states with increased EAT volume and dysfunctional adipocytes, EAT secretes an increased amount of adipocytokines and the resulting imbalance of proinflammatory and anti-inflammatory mediators potentially causes atherogenic effects on the coronary vessel wall in a paracrine way ("outside-to-inside" signaling). These EAT-induced atherogenic effects are reported to increase the risk for the development of coronary artery disease, myocardial ischemia, high-risk plaque features, and future major adverse cardiac events. Coronary inflammation plays a key role in the development and progression of coronary artery disease; however, its noninvasive detection remains challenging. In future, this clinical dilemma might be changed by the CTA-derived analysis of the PCAT. On the basis of the concept of an "inside-to-outside" signaling between the inflamed coronary vessel wall and the surrounding PCAT recent evidence demonstrates that PCAT computed tomography attenuation especially around the right coronary artery derived from routine CTA is a promising imaging biomarker and "sensor" to noninvasively detect coronary inflammation. This review summarizes the biological and technical principles of CTA-derived PCAT analysis and highlights its clinical implications to improve modern cardiovascular prevention strategies.

Photobiomodulation Therapy on Myocardial Infarction in Rats: Transcriptional and Posttranscriptional Implications to Cardiac Remodeling

BACKGROUND AND OBJECTIVES

Induction of myocardial infarction (MI) in rats by occlusion of the left anterior descending coronary artery is an experimental model used in research to elucidate functional, structural, and molecular modifications associated with ischemic heart disease. Photobiomodulation therapy (PBMT) has become a therapeutic alternative by modulating various biological processes eliciting several effects, including anti-inflammatory and pro-proliferative actions. The main objective of this work was to evaluate the effect of PBMT in the modulation of transcriptional and post-transcriptional changes that occurred in myocardium signal transduction pathways after MI.

STUDY DESIGN/MATERIALS AND METHODS

Continuous wave (CW) non-thermal laser parameters were: 660 nm wavelength, power 15 mW, with a total energy of 0.9 J, fluence of 1.15 J/cm² , spot size of 0.785 cm² , and time of 60 seconds. Using in silico analysis, we selected and then, quantified the expression of messenger RNA (mRNA) of 47 genes of 9 signaling pathways associated with MI (angiogenesis, cell survival, hypertrophy, oxidative stress, apoptosis, extracellular matrix, calcium kinetics, cell metabolism, and inflammation). Messenger RNA expression quantification was performed in myocardial samples by polymerase chain reaction real-time array using TaqMan customized plates.

RESULTS

Our results evidenced that MI modified mRNA expression of several well-known biomarkers related to detrimental cardiac activity in almost all signaling pathways analyzed. However, PBMT reverted most of these transcriptional changes. More expressively, PBMT provoked a robust decrease in mRNA expression of molecules that participate in post-MI inflammation and ECM composition, such as IL-6, TNF receptor, TGFb1, and collagen I and III. Global microRNA (miRNA) expression analysis revealed that PBMT decreased miR-221, miR-34c, and miR-93 expressions post-MI, which are related to deleterious effects in cardiac remodeling.

CONCLUSION

Thus, the identification of transcriptional and post-transcriptional changes induced by PBMT may be used to interfere in the molecular dynamics of cardiac remodeling post-MI.

Proarrhythmic Electrical Remodeling by Noncardiomyocytes at Interfaces With Cardiomyocytes Under Oxidative Stress

Life-threatening ventricular arrhythmias, typically arising from interfaces between fibrosis and surviving cardiomyocytes, are feared sequelae of structurally remodeled hearts under oxidative stress. Incomplete understanding of the proarrhythmic electrical remodeling by fibrosis limits the development of novel antiarrhythmic strategies. To define the mechanistic determinants of the proarrhythmia in electrical crosstalk between cardiomyocytes and noncardiomyocytes, we developed a novel in vitro model of interface between neonatal rat ventricular cardiomyocytes (NRVMs) and controls [NRVMs or connexin43 (Cx43)-deficient HeLa cells] vs. Cx43⁺ noncardiomyocytes [aged rat ventricular myofibroblasts (ARVFs) or HeLaCx43 cells]. We performed high-speed voltage-sensitive optical imaging at baseline and following acute H₂O₂ exposure. In NRVM-NRVM and NRVM-HeLa controls, no arrhythmias occurred under either experimental condition. In the NRVM-ARVF and NRVM-HeLaCx43 groups, Cx43⁺ noncardiomyocytes enabled passive decremental propagation of electrical impulses and impaired NRVM activation and repolarization, thereby slowing conduction and prolonging action potential duration. Following H₂O₂ exposure, arrhythmia triggers, automaticity, and non-reentrant and reentrant arrhythmias emerged. This study reveals that myofibroblasts (which generate cardiac fibrosis) and other noncardiomyocytes can induce not only structural remodeling but also electrical remodeling and that electrical remodeling by noncardiomyocytes can be particularly arrhythmogenic in the presence of an oxidative burst. Synergistic electrical remodeling between H₂O₂ and noncardiomyocytes may account for the clinical arrhythmogenicity of myofibroblasts at fibrotic interfaces with cardiomyocytes in ischemic/non-ischemic cardiomyopathies. Understanding the enhanced arrhythmogenicity of synergistic electrical remodeling by H₂O₂ and noncardiomyocytes may guide novel safe-by-design antiarrhythmic strategies for next-generation iatrogenic interfaces between surviving native cardiomyocytes and exogenous stem cells or engineered tissues in cardiac regenerative therapies.

Prognostic Value of the Nutritional Risk Screening 2002 Scale in Patients With Acute Myocardial Infarction: Insights From the Retrospective Multicenter Study for Early Evaluation of Acute Chest Pain

BACKGROUND

The Nutritional Risk Screening 2002 (NRS-2002) scale is a rapid and effective screening instrument that assesses nutritional risk among hospitalized patients.

OBJECTIVE

The present study aimed to explore the prognostic value of the NRS-2002 scale in acute myocardial infarction (AMI) considering its uncertain role in this particular condition.

METHODS

Patients with AMI included in the Retrospective Multicenter Study for Early Evaluation of Acute Chest Pain were investigated. Kaplan-Meier survival analysis and Cox proportional hazards models were used to analyze the association between NRS-2002 and mortality in patients with AMI. The primary and secondary endpoints were all-cause and cardiac mortality during the follow-up period.

RESULTS

A total of 2307 patients were enrolled, among whom 246 (10.7%) died within a median follow-up duration of 10.67 (8.04-14.33) months. Kaplan-Meier analysis revealed that patients with an NRS-2002 score of 3 or higher had poorer cumulative survival than those with an NRS-2002 score lower than 3 (P < .001). In the multivariate Cox regression analysis, patients with an NRS-2002 score of 3 or higher had more than double the risk for all-cause mortality (hazard ratio, 2.25; 95% confidence interval, 1.50-3.40; P < .001) and twice the risk for cardiac-related mortality (hazard ratio, 2.01; 95% confidence interval, 1.29-3.13; P = .002) than did patients with lower scores.

CONCLUSIONS

Our results showed that the NRS-2002 screening instrument was an independent prognostic predictor for both all-cause and cardiac mortality in patients with AMI. Nutritional risk assessment based on the NRS-2002 scale may provide useful prognostic information of early nutritional risk stratification in patients with AMI.

Mediation of the association between polycyclic aromatic hydrocarbons exposure and telomere attrition by oxidative stress: A prospective cohort study

Previous studies have reported associations between polycyclic aromatic hydrocarbons (PAHs) exposure and telomere attrition, but the underlying mechanisms remain to be elucidated. This study aimed to explore the mediation role of oxidative stress on the effects of PAHs exposure on telomere attrition in a cohort study of 1180 coke-oven workers. We determined baseline urinary concentrations of ten urinary PAH metabolites, two oxidative stress biomarkers [8-hydroxydeoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-isoPGF2α)] and peripheral leukocytes telomere length (TL) in both baseline and follow-up visits. Mediation analysis was applied to assess effects of oxidative stress biomarkers on the PAHs-TL attrition associations. The baseline 8-OHdG had a significant dose-response relationship with TL decline [β(95 %CI) = 0.07(0.03-0.12), P = 0.001] and TL ratio [β(95 %CI)]=0.07 (0.02-0.12), P = 0.003]. Mediation analyses indicated that 8-OHdG mediated a separate 39.1 %, 47.0 %, 43.3 %, and 58.0 % of the associations between 1-hydroxynaphthalene (1-OHNa), 2-OHNa, ΣOHNa, 1-hydroxypyrene (1-OHP) and TL decline (P = 0.016, 0.008, 0.012, and 0.014, respectively). Additionally, 8-OHdG mediated a separate 44.8 %, 49.4 %, 49.2 %, and 35.5 % of the associations between 1-OHNa, 2-OHNa, ΣOHNa, 1-OHP and TL ratio (P = 0.012, 0.008, 0.012, and 0.046, respectively). Our study proposed the positive association of 8-OHdG with TL attrition and revealed the mediation roles of 8-OHdG in PAHs-TL attrition associations.

The association between dietary quality indices and serum telomerase activity in patient candidates for CABG

BACKGROUND

Diet and dietary habits are major determinants of human telomere length. Telomerase activity is affected mostly by oxidative stress and inflammation. However, the association of telomerase activity with dietary quality indices has not been evaluated before. In the current work, we aimed to test the association of telomerase activity with dietary antioxidant quality score (DAQ), dietary inflammatory index and dietary patterns in patients who were candidate for coronary artery bypass grafting surgery (CABG).

METHODS AND MATERIALS

In the current cross-sectional study, 454 candidates for the CABG were enrolled from Tehran Heart Center-Coronary Outcome Measurement (THC-COM) cohort. Laboratory measurements included Hb-A₁C, serum lipid profile, creatinine, blood urea nitrogen, hematocrit, lipoprotein (LP)-a, telomerase activity, serum vitamin D and C-reactive protein. Dietary status was measured by semiquantitative food frequency questionnaire, and dietary indices were calculated. Dietary patterns were extracted by factor analysis method.

RESULTS

High telomerase activity was associated with lower prevalence of myocardial infarction (MI) (P = 0.04), high dietary vitamin E and high total dietary antioxidant quality scores. Telomerase activity in top quartile of neo-traditional dietary pattern was higher than other quartiles (P = 0.021). No significant association between telomerase activity and other dietary patterns was obtained. Higher telomerase activity was also associated with higher serum creatinine and lower LP-(a) concentrations (P < 0.05).

CONCLUSION

To our findings, higher telomerase activity was associated with higher DAQ and lower MI prevalence. It seems that adherence to healthy diet increases serum telomerase activity and reduced telomerase concentration is associated with increased cardio-metabolic risk factors. Moreover, adherence to neo-traditional pattern with higher intake of low-fat dairy products was associated with higher telomerase activity.

LEVEL OF EVIDENCE

Level V: A well-designed observational cross-sectional study.

The Importance of Telomere Shortening for Atherosclerosis and Mortality

Telomeres are the protective end caps of chromosomes and shorten with every cell division. Short telomeres are associated with older age and adverse lifestyle factors. Leucocyte telomere length (LTL) has been proposed as a biomarker of biological age. The shortening of LTL with age is the result of the end-replication problem, environmental, and lifestyle-related factors. Epidemiologic studies have shown that LTL predicts cardiovascular disease, all-cause mortality, and death from vascular causes. Age appears to be an important co-variate that explains a substantial fraction of this effect. Although it has been proposed that short telomeres promote atherosclerosis and impair the repair of vascular lesions, existing results are inconsistent. Oxidative stress and chronic inflammation can both accelerate telomere shortening. Multiple factors, including homocysteine (HCY), vitamin B6, and vitamin B12 modulate oxidative stress and inflammation through direct and indirect mechanisms. This review provides a compact overview of telomere physiology and the utility of LTL measurements in atherosclerosis and cardiovascular disease. In addition, it summarizes existing knowledge regarding the impact of oxidative stress, inflammation, HCY, and B-vitamins on telomere function.

The Link between Chronic Stress and Accelerated Aging

People exposed to chronic stress age rapidly. The telomeres in their cells of all types shorten faster. Inflammation is another important feature of stress that, along with aging, accounts for the phenomenon of inflammaging. In addition to aging itself, inflammaging can contribute to the development of several pathologies, including atherosclerosis, diabetes, hypertension, and others. Oxidative stress is one of the main mechanisms related to stress. Oxidative stress is caused by the over-production of reactive oxygen species (ROS) that can damage various tissues. The main source of ROS is mitochondria. Being suppressed by mitochondrial mutations, mitophagy can aggravate the situation. In this case, the aging-specific pro-inflammatory changes are amplified. It happens because of the inability of cells to maintain the normal state of mitochondria. Macrophages are the crucial element of the innate immunity associated with the chronic inflammation and, subsequently, with the inflammaging. In this review, we focus on the therapy approaches potentially reducing the deleterious effects of oxidative stress. These include stimulation of mitophagy, activation of mitochondrial uncoupling, induction of the expression of the telomerase catalytic component gene, and use of antioxidants. Any method reducing oxidative stress should improve post-traumatic stress disorder.

The Application of Traditional Chinese Medicine Injection on Patients with Acute Coronary Syndrome during the Perioperative Period of Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

TCMI with the effect of Liqihuoxue and Yiqihuoxue has been applied as complementary therapies during the perioperative period of PCI for patients with ACS, while the recommended time points and plans of TCMI are still short of the support of evidence-based medicine.

METHODS

A systematic review and meta-analysis was conducted to evaluate the clinical efficacy and safety of TCMI on patients with ACS during the perioperative period of PCI. RCTs were searched based on standardized searching rules in seven medical databases from the inception up to August 2019. Two reviewers conducted the study selection, data extraction, and quality analysis independently. Data were analysed with the support of software RevMan and Stata.

RESULTS

A total of 68 articles with 6,043 patients were enrolled. The result of meta-analysis showed that the TCMI combined with western medicine was superior to the western medicine alone on clinical efficiency (before the PCI, before and after the PCI, or overall, P < 0.05), the occurrence of MACE (myocardial infarction and stenocardia: before the PCI, before and after the PCI, or overall, P < 0.05; arrhythmia: before and after the PCI, P < 0.05), and the level of inflammatory factors (hs-CRP: before the PCI, before and after the PCI, or overall, P < 0.05; IL-6: after the PCI, P < 0.05). The TCMI with the effect of Liqihuoxue obtained more support compared with Yiqihuoxue based on the result of meta-analysis.

CONCLUSIONS

TCMI with the effect of Liqihuoxue or Yiqihuoxue combined with western medicine generally showed the potential advantage on the treatment of ACS during the perioperative period of PCI. However, the optimal time point of intervention and recommended plan based on the effect still needs more clinical evidence. We consider that the research of precise and standardized application of TCMI will be a promising direction for TCM in the future.

Oxidative stress, telomeres and cellular senescence: What non-drug interventions might break the link?

Telomeres are higher order structures that cap and protect chromosome ends. Telomeric DNA naturally shortens during somatic cell division and as a result of oxidative stress. Excessive shortening disrupts the integrity of the telomere, causing cellular senescence, one of the hallmarks of organismal ageing. The accumulation of senescent cells with ageing contributes to the loss of tissue homeostasis and the development of age-related pathologies. Hence, counteracting telomere shortening may be one relevant approach to develop strategies for healthier ageing. In this review I present the case for the existence of a link between oxidative stress, accelerated telomere shortening and cellular senescence. I also examine findings from human observational studies exploring associations between telomere length and oxidative stress-related parameters. Finally, I discuss results from randomised control trials testing the impact of non-pharmacological lifestyle interventions on the maintenance of telomere length, considering the potential mechanisms that might be involved.

NADPH Oxidase Overactivity Underlies Telomere Shortening in Human Atherosclerosis

Telomere shortening and oxidative stress are involved in the pathogenesis of atherosclerosis. Different studies have shown that phagocytic NADPH oxidase is associated with this disease. This study aimed to investigate the association between phagocytic NADPH oxidase and telomere shortening in human atherosclerosis. To assess this potential association, telomere length and phagocytic NADPH oxidase activity were determined by PCR and chemiluminescence, respectively, in a population of asymptomatic subjects free of overt clinical atherosclerosis. We also measured serum 8-hydroxy-2-deoxyguanosine (8-OHdG) levels (an index of oxidative stress) and carotid intima-media thickness (IMT), a surrogate marker of atherosclerosis. After adjusting them for age and sex, telomere length inversely correlated (p < 0.05) with NADPH oxidase-mediated superoxide production, with 8-OHdG values, and with carotid IMT. Interestingly, the asymptomatic subjects with plaques have a lower telomere length (p < 0.05), and higher values of plasma 8-OHdG and superoxide production (p < 0.05). These data were confirmed in a second population in which patients with coronary artery disease showed lower telomere length and higher 8-OHdG and superoxide production than the asymptomatic subjects. In both studies, NADPH oxidase-dependent superoxide production in phagocytic cells was only due to the specific expression of the Nox2 isoform. In conclusion, these findings suggest that phagocytic NADPH oxidase may be involved in oxidative stress-mediated telomere shortening, and that this axis may be critically involved in human atherosclerosis.

The role of adipose tissue in cardiovascular health and disease

Accumulating knowledge on the biology and function of the adipose tissue has led to a major shift in our understanding of its role in health and disease. The adipose tissue is now recognized as a crucial regulator of cardiovascular health, mediated by the secretion of several bioactive products, including adipocytokines, microvesicles and gaseous messengers, with a wide range of endocrine and paracrine effects on the cardiovascular system. The adipose tissue function and secretome are tightly controlled by complex homeostatic mechanisms and local cell-cell interactions, which can become dysregulated in obesity. Systemic or local inflammation and insulin resistance lead to a shift in the adipose tissue secretome from anti-inflammatory and anti-atherogenic towards a pro-inflammatory and pro-atherogenic profile. Moreover, the interplay between the adipose tissue and the cardiovascular system is bidirectional, with vascular-derived and heart-derived signals directly affecting adipose tissue biology. In this Review, we summarize the current knowledge of the biology and regional variability of adipose tissue in humans, deciphering the complex molecular mechanisms controlling the crosstalk between the adipose tissue and the cardiovascular system, and their possible clinical translation. In addition, we highlight the latest developments in adipose tissue imaging for cardiovascular risk stratification and discuss how therapeutic targeting of the adipose tissue can improve prevention and treatment of cardiovascular disease.

Cellular senescence in cardiac diseases

Replicative capacity of somatic cells is limited. It indicates that aging also develops at the cellular level, and this is described as "cellular senescence". Senescent cells become flattened, enlarged, and irreversibly lose capacity for proliferation. Lack of specific and conclusive markers for cellular senescence makes it difficult to comprehensively define and understand this biological process especially in vivo. Molecules including p53, p21, p16^Ink4a, p38MAPK, and γH2AX, telomere attrition, enhanced signals for SA-β-gal, etc. are widely used to detect senescent cells, but these are indirect indicators of cellular senescence, and biological markers reflecting direct evidence need to be established. Genetic profiles are altered in senescent cells, letting these cells secrete pro-inflammatory molecules. Aging or age-related disorders including heart failure and atherosclerotic diseases link with an accumulation of cells undergoing cellular senescence in cardiovascular systems including heart and vessels. Senescent cells become pathogenic in most cases by mediating chronic sterile inflammation and tissue remodeling. A recent conceptual as well as technical breakthrough in this research area is "senolysis", meaning the specific elimination of senescent cells. Genetic as well as pharmacological models with senolysis contributed to reverse aging phenotypes and ameliorated pathologies in age-related disorders without enhancing the risk of tumorigenesis, and opened a new avenue for aging research. Several compounds are identified as senolytics, and some are already tested in clinical settings. It was recently reported that senolysis reverses aging phenotype in cardiovascular disorders. Generating therapies targeting suppression or elimination of senescent cells would inhibit the progression of undesirable aspects of aging, and become promising therapies for cardiac diseases.

State-of-the-art review article. Atherosclerosis affecting fat: What can we learn by imaging perivascular adipose tissue?

Perivascular adipose tissue (PVAT) surrounding the human coronary arteries, secretes a wide range of adipocytokines affecting the biology of the adjacent vascular wall in a paracrine way. However, we have recently found that PVAT also behaves as a sensor of signals coming from the vascular wall, to which it reacts by changing its morphology and secretory profile. Indeed, vascular inflammation, a key feature of vascular disease pathogenesis, leads to the release of inflammatory signals that disseminate into local fat, inducing local lipolysis and inhibiting adipogenesis. This ability of PVAT to sense inflammatory signals from the vascular wall, can be used as a "thermometer" of the vascular wall, allowing for non-invasive detection of coronary inflammation. Vascular inflammation induces a shift of PVAT's composition from lipid to aqueous phase, resulting into increased computed tomography (CT) attenuation around the inflamed artery, forming a gradient with increasing attenuation closer to the inflamed coronary artery wall. These spatial changes in PVAT's attenuation are easily detected around culprit lesions during acute coronary syndromes. A new biomarker designed to captured these spatial changes in PVAT's attenuation around the human coronary arteries, the Fat Attenuation Index (FAI), has additional predictive value in stable patients for cardiac mortality and non-fatal heart attacks, above the prediction provided by the current state of the art that includes risk factors, calcium score and presence of high risk plaque features. The use of perivascular FAI in clinical practice may change the way we interpret cardiovascular CT angiography, as it is applicable to any coronary CT angiogram, and it offers dynamic information about the inflammatory burden of the coronary arteries, providing potential guidance for preventive measures and invasive treatments.

Impaired Vascular Redox Signaling in the Vascular Complications of Obesity and Diabetes Mellitus

Significance: Oxidative stress, a crucial regulator of vascular disease pathogenesis, may be involved in the vascular complications of obesity, systemic insulin resistance (IR), and diabetes mellitus (DM). Recent Advances: Excessive production of reactive oxygen species in the vascular wall has been linked with vascular disease pathogenesis. Recent evidence has revealed that vascular redox state is dysregulated in cases of obesity, systemic IR, and DM, potentially participating in the well-known vascular complications of these disease entities. Critical Issues: The detrimental effects of obesity and the metabolic syndrome on vascular biology have been extensively described at a clinical level. Further, vascular oxidative stress has often been associated with the presence of obesity and IR as well as with a variety of detrimental vascular phenotypes. However, the mechanisms of vascular redox state regulation under conditions of obesity and systemic IR, as well as their clinical relevance, are not adequately explored. In addition, the notion of vascular IR, and its relationship with systemic parameters of obesity and systemic IR, is not fully understood. In this review, we present all the important components of vascular redox state and the evidence linking oxidative stress with obesity and IR. Future Directions: Future studies are required to describe the cellular effects and the translational potential of vascular redox state in the context of vascular disease. In addition, further elucidation of the direct vascular effects of obesity and IR is required for better management of the vascular complications of DM.

Obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is increasing in prevalence due to rising obesity. While OSA is a disorder primarily of the upper airway during sleep, its pathophysiological impact on other body systems is increasingly recognised. There has been interest in the prevalence of OSA in different ophthalmic conditions and possible causation has been postulated. As OSA is common, it can be expected that people with co-existent OSA will be found in any ophthalmic disease population studied. To determine with confidence the significance of finding patients with OSA in a particular cohort requires a well matched control group, ideally matched for age, obesity, gender and co-morbidities. Only if one can say with certainty that the prevalence of OSA is higher in a group with a particular co-existent ophthalmic disease can we begin to speculate about possible mechanisms for the overlap in these conditions. Possible mechanisms for how OSA might affect the eye are discussed in this review. The current literature is reviewed with respect to diabetic retinopathy, glaucoma, floppy eyelid syndrome, non-arteritic ischaemic optic neuropathy, keratoconus and AMD. Associations with OSA have been found, but robust prospective studies using multi-channel sleep studies to diagnose OSA are lacking. Gaps remain in the evidence and in our knowledge. It is hoped that this review will highlight the need for ophthalmologists to consider OSA in their patients. It also makes recommendations for future research, especially to consider whether therapies for OSA can also be effective for ophthalmic disorders.

Intermittent hypoxia, cardiovascular disease and obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is a common disorder and is associated with cardiovascular disease. Continuous positive airway pressure (CPAP), whilst reducing blood pressure, has not been shown to reduce cardiovascular events when used as a treatment solely for this purpose in patients with previous cardiovascular disease. Developing a better understanding of the mechanisms underlying cardiovascular disease in OSA is important to develop new treatments. Potential causative mechanisms for cardiovascular disease in OSA include arousal induced sympathetic activation, large intrathoracic pressure swings leading to shear stress on the heart and great vessels, and intermittent hypoxia (IH). This review discusses the role of IH, as a major physiological consequence of OSA, in the development of cardiovascular disease.