PBX/Knotted 1 homeobox-2 (PKNOX2) is a novel regulator of myocardial fibrosis

Much effort has been made to uncover the cellular heterogeneities of human hearts by single-nucleus RNA sequencing. However, the cardiac transcriptional regulation networks have not been systematically described because of the limitations in detecting transcription factors. In this study, we optimized a pipeline for isolating nuclei and conducting single-nucleus RNA sequencing targeted to detect a higher number of cell signal genes and an optimal number of transcription factors. With this unbiased protocol, we characterized the cellular composition of healthy human hearts and investigated the transcriptional regulation networks involved in determining the cellular identities and functions of the main cardiac cell subtypes. Particularly in fibroblasts, a novel regulator, PKNOX2, was identified as being associated with physiological fibroblast activation in healthy hearts. To validate the roles of these transcription factors in maintaining homeostasis, we used single-nucleus RNA-sequencing analysis of transplanted failing hearts focusing on fibroblast remodelling. The trajectory analysis suggested that PKNOX2 was abnormally decreased from fibroblast activation to pathological myofibroblast formation. Both gain- and loss-of-function in vitro experiments demonstrated the inhibitory role of PKNOX2 in pathological fibrosis remodelling. Moreover, fibroblast-specific overexpression and knockout of PKNOX2 in a heart failure mouse model induced by transverse aortic constriction surgery significantly improved and aggravated myocardial fibrosis, respectively. In summary, this study established a high-quality pipeline for single-nucleus RNA-sequencing analysis of heart muscle. With this optimized protocol, we described the transcriptional regulation networks of the main cardiac cell subtypes and identified PKNOX2 as a novel regulator in suppressing fibrosis and a potential therapeutic target for future translational studies.

BACH1 regulates the differentiation of vascular smooth muscle cells from human embryonic stem cells via CARM1-mediated methylation of H3R17

The role of BACH1 in the process of vascular smooth muscle cell (VSMC) differentiation from human embryonic stem cells (hESCs) remains unknown. Here, we find that the loss of BACH1 in hESCs attenuates the expression of VSMC marker genes, whereas overexpression of BACH1 after mesoderm induction increases the expression of VSMC markers during in vitro hESC-VSMC differentiation. Mechanistically, BACH1 binds directly to coactivator-associated arginine methyltransferase 1 (CARM1) during in vitro hESC-VSMC differentiation, and this interaction is mediated by the BACH1 bZIP domain. BACH1 recruits CARM1 to VSMC marker gene promoters and promotes VSMC marker expression by increasing H3R17me2 modification, thus facilitating in vitro VSMC differentiation from hESCs after the mesoderm induction. The increased expression of VSMC marker genes by BACH1 overexpression is partially abolished by inhibition of CARM1 or the H3R17me2 inhibitor TBBD in hESC-derived cells. These findings highlight the critical role of BACH1 in hESC differentiation into VSMCs by CARM1-mediated methylation of H3R17.

BACH1 controls hepatic insulin signaling and glucose homeostasis in mice

Hepatic insulin resistance is central to the metabolic syndrome. Here we investigate the role of BTB and CNC homology 1 (BACH1) in hepatic insulin signaling. BACH1 is elevated in the hepatocytes of individuals with obesity and patients with non-alcoholic fatty liver disease (NAFLD). Hepatocyte-specific Bach1 deletion in male mice on a high-fat diet (HFD) ameliorates hyperglycemia and insulin resistance, improves glucose homeostasis, and protects against steatosis, whereas hepatic overexpression of Bach1 in male mice leads to the opposite phenotype. BACH1 directly interacts with the protein-tyrosine phosphatase 1B (PTP1B) and the insulin receptor β (IR-β), and loss of BACH1 reduces the interaction between PTP1B and IR-β upon insulin stimulation and enhances insulin signaling in hepatocytes. Inhibition of PTP1B significantly attenuates BACH1-mediated suppression of insulin signaling in HFD-fed male mice. Hepatic BACH1 knockdown ameliorates hyperglycemia and improves insulin sensitivity in diabetic male mice. These results demonstrate a critical function for hepatic BACH1 in the regulation of insulin signaling and glucose homeostasis.

Cardiac-specific BACH1 ablation attenuates pathological cardiac hypertrophy by inhibiting the Ang II type 1 receptor expression and the Ca2+/CaMKII pathway

AIMS

BACH1 is up-regulated in hypertrophic hearts, but its function in cardiac hypertrophy remains largely unknown. This research investigates the function and mechanisms of BACH1 in the regulation of cardiac hypertrophy.

METHODS AND RESULTS

Male cardiac-specific BACH1 knockout mice or cardiac-specific BACH1 transgenic (BACH1-Tg) mice and their respective wild-type littermates developed cardiac hypertrophy induced by angiotensin II (Ang II) or transverse aortic constriction (TAC). Cardiac-specific BACH1 knockout in mice protected the hearts against Ang II- and TAC-induced cardiac hypertrophy and fibrosis, and preserved cardiac function. Conversely, cardiac-specific BACH1 overexpression markedly exaggerated cardiac hypertrophy and fibrosis and reduced cardiac function in mice with Ang II- and TAC-induced hypertrophy. Mechanistically, BACH1 silencing attenuated Ang II- and norepinephrine-stimulated calcium/calmodulin-dependent protein kinase II (CaMKII) signalling, the expression of hypertrophic genes, and hypertrophic growth of cardiomyocytes. Ang II stimulation promoted the nuclear localization of BACH1, facilitated the recruitment of BACH1 to the Ang II type 1 receptor (AT1R) gene promoter, and then increased the expression of AT1R. Inhibition of BACH1 attenuated Ang II-stimulated AT1R expression, cytosolic Ca2+ levels, and CaMKII activation in cardiomyocytes, whereas overexpression of BACH1 led to the opposite effects. The increased expression of hypertrophic genes induced by BACH1 overexpression upon Ang II stimulation was suppressed by CaMKII inhibitor KN93. The AT1R antagonist, losartan, significantly attenuated BACH1-mediated CaMKII activation and cardiomyocyte hypertrophy under Ang II stimulation in vitro. Similarly, Ang II-induced myocardial pathological hypertrophy, cardiac fibrosis, and dysfunction in BACH1-Tg mice were blunted by treatment with losartan.

CONCLUSION

This study elucidates a novel important role of BACH1 in pathological cardiac hypertrophy by regulating the AT1R expression and the Ca2+/CaMKII pathway, and highlights potential therapeutic target in pathological cardiac hypertrophy.

Coronary Collateral Circulation: A New Predictor of Mortality in Heart Transplant Recipients With Allograft Vasculopathy

Coronary collateral arteries (CCAs) are anastomotic channels between vessels; although beneficial in atherosclerosis, their role in heart transplantation (HT) recipients is underinvestigated. CCAs initially develop as microcirculation and cardiac allograft vasculopathy (CAV), promoting immune-dependent proliferative angiogenic response, and play a role in their development. In our hypothesis, ischemia induced by coronary microvascular dysfunction (CMD) triggers the development of CCAs, which are, in turn, less functional as affected by CAV themselves.

Methods

One hundred twenty-one patients receiving HT at our institution were retrospectively evaluated and were included if transthoracic echocardiography with coronary flow velocity reserve (CFVR) assessment and coronary angiography were performed. CMD was defined as CFVR of ≤2.5. Patients with CAV were enrolled, and their angiograms were reviewed to evaluate the presence of CCAs. Cardiovascular mortality was assessed as the main clinical outcome.

Results

Forty patients were found to have CCAs. Patients with CCAs have lower CFVR than those without CCAs (2.22 ± 0.72 versus 2.69 ± 0.92;P = 0.003), reflecting in different rates of CMD in the 2 groups (72.5% versus 37%; P < 0.001). CMD is associated with higher CAV grades (P < 0.001), which are also associated with CCAs (P < 0.001). Patients with poorly developed CCAs have lower CFVR (P < 0.001). At multivariable analysis, CMD (P = 0.008) and higher CAV grades (P = 0.005) are independent predictors of CCAs. During the median follow-up time of 10.2 (6.6-13.3) y, patients with CCAs have been found to have higher mortality than those without CCAs (57.5% versus 32.1%; P = 0.007). CCAs are associated with a lower probability of survival also in patients with CMD (P < 0.001) and are independent predictors of mortality (P < 0.001).

Conclusions

Our results demonstrate an interplay between CAV, CMD, and CCAs. We confirm that CAV is associated with CMD, and we show, for the first time, that CMD is associated with CCAs. CCAs are pathophysiologically associated with more severe graft vasculopathy and independently predict mortality after HT.

BACH1 deficiency prevents neointima formation and maintains the differentiated phenotype of vascular smooth muscle cells by regulating chromatin accessibility

The transcription factor BTB and CNC homology 1(BACH1) has been linked to coronary artery disease risk by human genome-wide association studies, but little is known about the role of BACH1 in vascular smooth muscle cell (VSMC) phenotype switching and neointima formation following vascular injury. Therefore, this study aims to explore the role of BACH1 in vascular remodeling and its underlying mechanisms. BACH1 was highly expressed in human atherosclerotic plaques and has high transcriptional factor activity in VSMCs of human atherosclerotic arteries. VSMC-specific loss of Bach1 in mice inhibited the transformation of VSMC from contractile to synthetic phenotype and VSMC proliferation and attenuated the neointimal hyperplasia induced by wire injury. Mechanistically, BACH1 suppressed chromatin accessibility at the promoters of VSMC marker genes via recruiting histone methyltransferase G9a and cofactor YAP and maintaining the H3K9me2 state, thereby repressing VSMC marker genes expression in human aortic smooth muscle cells (HASMCs). BACH1-induced repression of VSMC marker genes was abolished by the silencing of G9a or YAP. Thus, these findings demonstrate a crucial regulatory role of BACH1 in VSMC phenotypic transition and vascular homeostasis and shed light on potential future protective vascular disease intervention via manipulation of BACH1.

How to optimize the adherence to a guideline-directed medical therapy in the secondary prevention of cardiovascular diseases: a clinical consensus statement from the European Association of Preventive Cardiology

A key factor to successful secondary prevention of cardiovascular disease (CVD) is optimal patient adherence to treatment. However, unsatisfactory rates of adherence to treatment for CVD risk factors and CVD have been observed consistently over the last few decades. Hence, achieving optimal adherence to lifestyle measures and guideline-directed medical therapy in secondary prevention and rehabilitation is a great challenge to many healthcare professionals. Therefore, in this European Association of Preventive Cardiology clinical consensus document, a modern reappraisal of the adherence to optimal treatment is provided, together with simple, practical, and feasible suggestions to achieve this goal in the clinical setting, focusing on evidence-based concepts.

Epigenetics in the primary and secondary prevention of cardiovascular disease: influence of exercise and nutrition

Increasing evidence links changes in epigenetic systems, such as DNA methylation, histone modification, and non-coding RNA expression, to the occurrence of cardiovascular disease (CVD). These epigenetic modifications can change genetic function under influence of exogenous stimuli and can be transferred to next generations, providing a potential mechanism for inheritance of behavioural intervention effects. The benefits of exercise and nutritional interventions in the primary and secondary prevention of CVD are well established, but the mechanisms are not completely understood. In this review, we describe the acute and chronic epigenetic effects of physical activity and dietary changes. We propose exercise and nutrition as potential triggers of epigenetic signals, promoting the reshaping of transcriptional programmes with effects on CVD phenotypes. Finally, we highlight recent developments in epigenetic therapeutics with implications for primary and secondary CVD prevention.

Translational opportunities of single-cell biology in atherosclerosis

The advent of single-cell biology opens a new chapter for understanding human biological processes and for diagnosing, monitoring, and treating disease. This revolution now reaches the field of cardiovascular disease (CVD). New technologies to interrogate CVD samples at single-cell resolution are allowing the identification of novel cell communities that are important in shaping disease development and direct towards new therapeutic strategies. These approaches have begun to revolutionize atherosclerosis pathology and redraw our understanding of disease development. This review discusses the state-of-the-art of single-cell analysis of atherosclerotic plaques, with a particular focus on human lesions, and presents the current resolution of cellular subpopulations and their heterogeneity and plasticity in relation to clinically relevant features. Opportunities and pitfalls of current technologies as well as the clinical impact of single-cell technologies in CVD patient care are highlighted, advocating for multidisciplinary and international collaborative efforts to join the cellular dots of CVD.

From novel discovery tools and biomarkers to precision medicine-basic cardiovascular science highlights of 2021/22

Here, we review the highlights of cardiovascular basic science published in 2021 and early 2022 on behalf of the European Society of Cardiology Council for Basic Cardiovascular Science. We begin with non-coding RNAs which have emerged as central regulators cardiovascular biology, and then discuss how technological developments in single-cell 'omics are providing new insights into cardiovascular development, inflammation, and disease. We also review recent discoveries on the biology of extracellular vesicles in driving either protective or pathogenic responses. The Nobel Prize in Physiology or Medicine 2021 recognized the importance of the molecular basis of mechanosensing and here we review breakthroughs in cardiovascular sensing of mechanical force. We also summarize discoveries in the field of atherosclerosis including the role of clonal haematopoiesis of indeterminate potential, and new mechanisms of crosstalk between hyperglycaemia, lipid mediators, and inflammation. The past 12 months also witnessed major advances in the field of cardiac arrhythmia including new mechanisms of fibrillation. We also focus on inducible pluripotent stem cell technology which has demonstrated disease causality for several genetic polymorphisms in long-QT syndrome and aortic valve disease, paving the way for personalized medicine approaches. Finally, the cardiovascular community has continued to better understand COVID-19 with significant advancement in our knowledge of cardiovascular tropism, molecular markers, the mechanism of vaccine-induced thrombotic complications and new anti-viral therapies that protect the cardiovascular system.

Crosstalk between high-density lipoproteins and endothelial cells in health and disease: Insights into sex-dependent modulation

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Intense research in vascular biology has advanced our knowledge of molecular mechanisms of its onset and progression until complications; however, several aspects of the patho-physiology of atherosclerosis remain to be further elucidated. Endothelial cell homeostasis is fundamental to prevent atherosclerosis as the appearance of endothelial cell dysfunction is considered the first pro-atherosclerotic vascular modification. Physiologically, high density lipoproteins (HDLs) exert protective actions for vessels and in particular for ECs. Indeed, HDLs promote endothelial-dependent vasorelaxation, contribute to the regulation of vascular lipid metabolism, and have immune-modulatory, anti-inflammatory and anti-oxidative properties. Sex- and gender-dependent differences are increasingly recognized as important, although not fully elucidated, factors in cardiovascular health and disease patho-physiology. In this review, we highlight the importance of sex hormones and sex-specific gene expression in the regulation of HDL and EC cross-talk and their contribution to cardiovascular disease.

Coronary Flow Evaluation in Heart Transplant Patients Compared to Healthy Controls Documents the Superiority of Coronary Flow Velocity Reserve Companion as Diagnostic and Prognostic Tool

Background

Distinct contributions by functional or structural alterations of coronary microcirculation in heart transplantation (HT) and their prognostic role have not been fully elucidated. We aimed to identify the mechanisms of coronary microvascular dysfunction (CMD) in HT and their prognostic implications.

Methods

134 patients, surviving at least 5 years after HT, without evidence of angiographic vasculopathy or symptoms/signs of rejection were included. 50 healthy volunteers served as controls. All underwent the assessment of rest and hyperemic coronary diastolic peak flow velocity (DPVr and DPVh) and coronary flow velocity reserve (CFVR) and its inherent companion that is based on the adjusted quadratic mean: CCFVR = √{(DPVr)2 + (DPVh)2}. Additionally, basal and hyperemic coronary microvascular resistance (BMR and HMR) were estimated.

Results

Based on CFVR and DPVh, HT patients can be assigned to four endotypes: endotype 1, discordant with preserved CFVR (3.1 ± 0.4); endotype 2, concordant with preserved CFVR (3.4 ± 0.5); endotype 3, concordant with impaired CFVR (1.8 ± 0.3) and endotype 4, discordant with impaired CFVR (2.0 ± 0.2). Intriguingly, endotype 1 showed lower DPVr (p &lt; 0.0001) and lower DPVh (p &lt; 0.0001) than controls with lower CFVR (p &lt; 0.0001) and lower CCFVR (p &lt; 0.0001) than controls. Moreover, both BMR and HMR were higher in endotype 1 than in controls (p = 0.001 and p &lt; 0.0001, respectively), suggesting structural microvascular remodeling. Conversely, endotype 2 was comparable to controls. A 13/32 (41%) patients in endotype 1 died in a follow up of 28 years and mortality rate was comparable to endotype 3 (14/31, 45%). However, CCFVR was &lt; 80 cm/s in all 13 deaths of endotype 1 (characterized by preserved CFVR). At multivariable analysis, CMD, DPVh &lt; 75 cm/s and CCFVR &lt; 80 cm/s were independent predictors of mortality. The inclusion of CCFVR &lt; 80 cm/s to models with clinical indicators of mortality better predicted survival, compared to only adding CMD or DPVh &lt; 75 cm/s (p &lt; 0.0001 and p = 0.03, respectively).

Conclusion

A normal CFVR could hide detection of microvasculopathy with high flow resistance and low flow velocities at rest. This microvasculopathy seems to be secondary to factors unrelated to HT (less rejections and more often diabetes). The combined use of CFVR and CCFVR provides more complete clinical and prognostic information on coronary microvasculopathy in HT.

Multiparametric analysis of coronary flow in psoriasis using a coronary flow reserve companion

BACKGROUND

Coronary microvascular dysfunction (CMD) is usually evaluated measuring coronary flow velocity reserve (CFVR). A more comprehensive analysis of CFVR including additional consideration of the associated logical companion-CFVR, where hyperemic diastolic coronary flow velocity may act as surrogate, was applied in this study to elucidate the mechanism of CMD in psoriasis.

METHODS AND RESULTS

Coronary flow velocity reserve was analysed using transthoracic echocardiographs of 127 psoriasis patients (age 36 ± 8 years; 104 males) and of 52 sex- and age-matched healthy controls. CFVR determination was repeated in the patient subgroup (n = 78) receiving anti-inflammatory therapy. Baseline and hyperemic microvascular resistance (MR) were calculated. CMD was defined as CFVR ≤ 2.5. Four endotypes of CMD were identified referring to concordant or discordant impairments of hyperemic flow or CFVR. We evaluated the companion-CFVR, as derived from the quadratic mean of hyperemic and diastolic flow velocity at rest. Coronary flow parameters, including CFVR (p = 0.01), were different among the two endotypes having CFVR > 2.5. Specifically, all 11 (14%) patients with CFVR deterioration despite therapy, belonged to endotype 1, and had higher baseline and hyperemic MR (p < 0.0001, both). Interestingly, while CFVR was comparable in patients with worsened versus those with improved CFVR, the companion-CFVR could discriminate by being lower in patients with worsened CFVR (p = 0.01).

CONCLUSIONS

The reduced CFVR in psoriasis is driven by decreased companion-CFVR, combined with increased hyperemic MR. Adoption of the mandatory companion-CFVR enables a personalized characterization superior to that achieved by exclusive consideration of CFVR.

Deletion of BACH1 Attenuates Atherosclerosis by Reducing Endothelial Inflammation

BACKGROUND

The transcription factor BACH1 (BTB and CNC homology 1) suppressed endothelial cells (ECs) proliferation and migration and impaired angiogenesis in the ischemic hindlimbs of adult mice. However, the role and underlying mechanisms of BACH1 in atherosclerosis remain unclear.

METHODS

Mouse models of atherosclerosis in endothelial cell (EC)-specific-Bach1 knockout mice were used to study the role of BACH1 in the regulation of atherogenesis and the underlying mechanisms.

RESULTS

Genetic analyses revealed that coronary artery disease-associated risk variant rs2832227 was associated with BACH1 gene expression in carotid plaques from patients. BACH1 was upregulated in ECs of human and mouse atherosclerotic plaques. Endothelial Bach1 deficiency decreased turbulent blood flow- or western diet-induced atherosclerotic lesions, macrophage content in plaques, expression of endothelial adhesion molecules (ICAM1 [intercellular cell adhesion molecule-1] and VCAM1 [vascular cell adhesion molecule-1]), and reduced plasma TNF-α (tumor necrosis factor-α) and IL-1β levels in atherosclerotic mice. BACH1 deletion or knockdown inhibited monocyte-endothelial adhesion and reduced oscillatory shear stress or TNF-α-mediated induction of endothelial adhesion molecules and/or proinflammatory cytokines in mouse ECs, human umbilical vein ECs, and human aortic ECs. Mechanistic studies showed that upon oscillatory shear stress or TNF-α stimulation, BACH1 and YAP (yes-associated protein) were induced and translocated into the nucleus in ECs. BACH1 upregulated YAP expression by binding to the YAP promoter. BACH1 formed a complex with YAP inducing the transcription of adhesion molecules. YAP overexpression in ECs counteracted the antiatherosclerotic effect mediated by Bach1-deletion in mice. Rosuvastatin inhibited BACH1 expression by upregulating microRNA let-7a in ECs, and decreased Bach1 expression in the vascular endothelium of hyperlipidemic mice. BACH1 was colocalized with YAP, and the expression of BACH1 was positively correlated with YAP and proinflammatory genes, as well as adhesion molecules in human atherosclerotic plaques.

CONCLUSIONS

These data identify BACH1 as a mechanosensor of hemodynamic stress and reveal that the BACH1-YAP transcriptional network is essential to vascular inflammation and atherogenesis. BACH1 shows potential as a novel therapeutic target in atherosclerosis.

Single-Cell Analysis Identify Transcription Factor BACH1 as a Master Regulator Gene in Vascular Cells During Aging

Vascular aging is a potent driver of cardiovascular and cerebrovascular diseases. Vascular aging features cellular and functional changes, while its molecular mechanisms and the cell heterogeneity are poorly understood. This study aims to 1) explore the cellular and molecular properties of aged cardiac vasculature in monkey and mouse and 2) demonstrate the role of transcription factor BACH1 in the regulation of endothelial cell (EC) senescence and its mechanisms. Here we analyzed published single-cell RNA sequencing (scRNA-seq) data from monkey coronary arteries and aortic arches and mouse hearts. We revealed that the gene expression of YAP1, insulin receptor, and VEGF receptor 2 was downregulated in both aged ECs of coronary arteries’ of monkey and aged cardiac capillary ECs of mouse, and proliferation-related cardiac capillary ECs were significantly decreased in aged mouse. Increased interaction of ECs and immunocytes was observed in aged vasculature of both monkey and mouse. Gene regulatory network analysis identified BACH1 as a master regulator of aging-related genes in both coronary and aorta ECs of monkey and cardiac ECs of mouse. The expression of BACH1 was upregulated in aged cardiac ECs and aortas of mouse. BACH1 aggravated endothelial cell senescence under oxidative stress. Mechanistically, BACH1 occupied at regions of open chromatin and bound to CDKN1A (encoding for P21) gene enhancers, activating its transcription in senescent human umbilical vein endothelial cells (HUVECs). Thus, these findings demonstrate that BACH1 plays an important role in endothelial cell senescence and vascular aging.

Correction to: Blood Pressure-Lowering Therapy

The Open Access chapter ‘Blood Pressure-Lowering Therapy’ was published online unfortunately without the Conflict of Interest statement. The COI statement should appear as:

Sex and gender in cardiovascular medicine: presentation and outcomes of acute coronary syndrome

Although health disparities in women presenting with acute coronary syndrome (ACS) have received growing attention in recent years, clinical outcomes from ACS are still worse for women than for men. Women continue to experience higher patient and system delays and receive less aggressive invasive treatment and pharmacotherapies. Gender- and sex-specific variables that contribute to ACS vulnerability remain largely unknown. Notwithstanding the sex differences in baseline coronary anatomy and function, women and men are treated the same based on guidelines that were established from experimental and clinical trial data over-representing the male population. Importantly, younger women have a particularly unfavourable prognosis and a plethora of unanswered questions remains in this younger population. The present review summarizes contemporary evidence for gender and sex differences in vascular biology, clinical presentation, and outcomes of ACS. We further discuss potential mechanisms and non-traditional risk conditions modulating the course of disease in women and men, such as unrecognized psychosocial factors, sex-specific vascular and neural stress responses, and the potential impact of epigenetic modifications.

The Endothelium Is Both a Target and a Barrier of HDL's Protective Functions

The vascular endothelium serves as a barrier between the intravascular and extravascular compartments. High-density lipoproteins (HDL) have two kinds of interactions with this barrier. First, bloodborne HDL must pass the endothelium to access extravascular tissues, for example the arterial wall or the brain, to mediate cholesterol efflux from macrophages and other cells or exert other functions. To complete reverse cholesterol transport, HDL must even pass the endothelium a second time to re-enter circulation via the lymphatics. Transendothelial HDL transport is a regulated process involving scavenger receptor SR-BI, endothelial lipase, and ATP binding cassette transporters A1 and G1. Second, HDL helps to maintain the integrity of the endothelial barrier by (i) promoting junction closure as well as (ii) repair by stimulating the proliferation and migration of endothelial cells and their progenitor cells, and by preventing (iii) loss of glycocalix, (iv) apoptosis, as well as (v) transmigration of inflammatory cells. Additional vasoprotective functions of HDL include (vi) the induction of nitric oxide (NO) production and (vii) the inhibition of reactive oxygen species (ROS) production. These vasoprotective functions are exerted by the interactions of HDL particles with SR-BI as well as specific agonists carried by HDL, notably sphingosine-1-phophate (S1P), with their specific cellular counterparts, e.g., S1P receptors. Various diseases modify the protein and lipid composition and thereby the endothelial functionality of HDL. Thorough understanding of the structure-function relationships underlying the multiple interactions of HDL with endothelial cells is expected to elucidate new targets and strategies for the treatment or prevention of various diseases.

Endothelial function in cardiovascular medicine: a consensus paper of the European Society of Cardiology Working Groups on Atherosclerosis and Vascular Biology, Aorta and Peripheral Vascular Diseases, Coronary Pathophysiology and Microcirculation, and Thrombosis

Endothelial cells (ECs) are sentinels of cardiovascular health. Their function is reduced by the presence of cardiovascular risk factors, and is regained once pathological stimuli are removed. In this European Society for Cardiology Position Paper, we describe endothelial dysfunction as a spectrum of phenotypic states and advocate further studies to determine the role of EC subtypes in cardiovascular disease. We conclude that there is no single ideal method for measurement of endothelial function. Techniques to measure coronary epicardial and micro-vascular function are well established but they are invasive, time-consuming, and expensive. Flow-mediated dilatation (FMD) of the brachial arteries provides a non-invasive alternative but is technically challenging and requires extensive training and standardization. We, therefore, propose that a consensus methodology for FMD is universally adopted to minimize technical variation between studies, and that reference FMD values are established for different populations of healthy individuals and patient groups. Newer techniques to measure endothelial function that are relatively easy to perform, such as finger plethysmography and the retinal flicker test, have the potential for increased clinical use provided a consensus is achieved on the measurement protocol used. We recommend further clinical studies to establish reference values for these techniques and to assess their ability to improve cardiovascular risk stratification. We advocate future studies to determine whether integration of endothelial function measurements with patient-specific epigenetic data and other biomarkers can enhance the stratification of patients for differential diagnosis, disease progression, and responses to therapy.

Endothelial dysfunction in COVID-19: a position paper of the ESC Working Group for Atherosclerosis and Vascular Biology, and the ESC Council of Basic Cardiovascular Science

The COVID-19 pandemic is an unprecedented healthcare emergency causing mortality and illness across the world. Although primarily affecting the lungs, the SARS-CoV-2 virus also affects the cardiovascular system. In addition to cardiac effects, e.g. myocarditis, arrhythmias, and myocardial damage, the vasculature is affected in COVID-19, both directly by the SARS-CoV-2 virus, and indirectly as a result of a systemic inflammatory cytokine storm. This includes the role of the vascular endothelium in the recruitment of inflammatory leucocytes where they contribute to tissue damage and cytokine release, which are key drivers of acute respiratory distress syndrome (ARDS), in disseminated intravascular coagulation, and cardiovascular complications in COVID-19. There is also evidence linking endothelial cells (ECs) to SARS-CoV-2 infection including: (i) the expression and function of its receptor angiotensin-converting enzyme 2 (ACE2) in the vasculature; (ii) the prevalence of a Kawasaki disease-like syndrome (vasculitis) in COVID-19; and (iii) evidence of EC infection with SARS-CoV-2 in patients with fatal COVID-19. Here, the Working Group on Atherosclerosis and Vascular Biology together with the Council of Basic Cardiovascular Science of the European Society of Cardiology provide a Position Statement on the importance of the endothelium in the underlying pathophysiology behind the clinical presentation in COVID-19 and identify key questions for future research to address. We propose that endothelial biomarkers and tests of function (e.g. flow-mediated dilatation) should be evaluated for their usefulness in the risk stratification of COVID-19 patients. A better understanding of the effects of SARS-CoV-2 on endothelial biology in both the micro- and macrovasculature is required, and endothelial function testing should be considered in the follow-up of convalescent COVID-19 patients for early detection of long-term cardiovascular complications.

Quantification of perivascular inflammation does not provide incremental prognostic value over myocardial perfusion imaging and calcium scoring

Aims

Perivascular fat attenuation index (FAI) has emerged as a novel coronary computed tomography angiography (CCTA)–based biomarker predicting cardiovascular outcomes by capturing early coronary inflammation. It is currently unknown whether FAI adds prognostic value beyond that provided by single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) and CCTA findings including coronary artery calcium scoring (CACS).

Methods and results

A total of 492 patients (mean age 62.5 ± 10.8 years) underwent clinically indicated multimodality CCTA and electrocardiography (ECG)-gated ^99mTc-tetrofosmin SPECT-MPI between May 2005 and December 2008 at our institution, and follow-up data on major adverse cardiovascular events (MACE) was obtained for 314 patients. FAI was obtained from CCTA images and was measured around the right coronary artery (FAI[RCA]), the left anterior descending artery (FAI[LAD]), and the left main coronary artery (FAI[LMCA]). During a median follow-up of 2.7 years, FAI[RCA] > − 70.1 was associated with an increased rate of MACE (log rank p = 0.049), while no such association was seen for FAI[LAD] or FAI[LMCA] (p = NS). A multivariate Cox regression model accounting for cardiovascular risk factors, CCTA and SPECT-MPI findings identified FAI[RCA] as an independent predictor of MACE (HR 2.733, 95% CI: 1.220–6.123, p = 0.015). However, FAI[RCA] was no longer a significant predictor of MACE after adding CACS (p = 0.279). A first-order interaction term consisting of sex and FAI[RCA] was significant in both models (HR 2.119, 95% CI: 1.218–3.686, p = 0.008; and HR 2.071, 95% CI: 1.111–3.861, p = 0.022).

Conclusion

FAI does not add incremental prognostic value beyond multimodality MPI/CCTA findings including CACS. The diagnostic value of FAI[RCA] is significantly biased by sex.

Multiparametric evaluation of coronary flow predicts long-term outcome in heart transplantation: from coronary flow velocity reserve to its newly introduced companion

Background

Coronary microvascular dysfunction (CMD) leads to a worse prognosis in heart transplantation (HT) patients. Coronary flow velocity reserve (CFVR) estimates the physiologic impact of allograft disease on the coronary circulation.

Purpose

Our aim was to determine the prognostic role of CFVR and its companion (CFVRC) on long-term survival of HT patients with a follow-up of 28 years.

Methods

134 HT patients, surviving at least 5 years after HT, with normal systolic ventricular function and no evidence of angiographic allograft vasculopathy or symptoms/signs of rejection were included. The enrolled population underwent echocardiographic evaluation of microvascular function by the assessment of both the ratio of hyperemic to rest diastolic peak velocity (DPVh and DPVr). These measurements yield CFVR and its associated companion, defined as CFVRC = √{(DPVr)2 + (DPVh)2}, as well as basal and hyperemic coronary microvascular resistance (BMR and HMR). A CFVR≤2.5 was considered abnormal; the median value of DPVh (75 cm/s) and CFVRC (80 cm/s) were utilized to dichotomize the population.

Results

Based on CFVR and DPVh, HT patients can be assigned to four groups: group 1 (n=32), discordant with preserved CFVR (3.1±0.4); group 2 (n=60), concordant with preserved CFVR (3.4±0.5); group 3 (n=31), concordant with impaired CFVR (1.8±0.3) and group 4 (n=11), discordant with impaired CFVR (2.0±0.2). Survival for each patient group is presented in the Figure (panel A). Specifically, survival was similar in group 1 when compared to group 3 (p=0.8), but significantly lower when compared to group 2 (p=0.03). Therefore, a normal CFVR (&gt;2.5) may not be able to predict the unfavourable long-term outcome. CFVR in fact is an incomplete dimensionless ratio; if the paired velocities are low with high BMR and HMR (group 1), the use of CFVR alone may miss some events, that are yet captured by CFVRC. Differences between survivors and no survivors are presented in the Table. At multivariable survival analysis, CMD, DPVh&lt;75 cm/s, CFVRC&lt;80 cm/s were independent predictors of mortality in HT patients. Consequently, we evaluated the added role of the CMD, DPVh&lt;75 cm/s and CFVRC&lt;80 cm/s to prognostic models including the clinical (Figure, panel B) predictors of mortality. The inclusion of CFVRC&lt;80 cm/s to model with clinical predictors of mortality permitted better prediction of survival in HT patients, compared to only adding CMD or DPVh&lt;75 cm/s.

Conclusions

This study is the first to demonstrate that the CFVR alone, even representing a determinant of survival in long-term HT patients, is not sufficient to completely predict long-term survival in HT patients. In comparison to CMD and DPVh, the CFVRC provides a significant improvement in survival prediction in long-term HT patients. Thus, the proposed multiparametric approach offers a more comprehensive evaluation of prognosis in HT patients, just by applying available data without the need to perform additional measurements.

Funding Acknowledgement

Type of funding source: None

Coronary flow evaluation in heart transplant patients compared to healthy controls documents the inadequacy of the coronary flow velocity reserve metric

Background

Coronary microvasculopathy has impact on prognosis in heart transplantation (HT). Distinct contributions by functional or structural alterations of coronary microcirculation in HT and their prognostic role have not been fully elucidated.

Purpose

We aimed to identify the mechanisms of coronary microvascular impairment in HT and their possible prognostic implications by applying a comprehensive analysis in a comparative study.

Methods

Included were 134 patients, surviving at least 5 years, with normal systolic function and no evidence of allograft vasculopathy or symptoms/signs of rejection. To permit comparison, 50 healthy volunteers without cardiovascular diseases, and matched for age and sex, served as controls. All underwent echocardiographic evaluation of microvascular function by the assessment of rest and hyperemic diastolic peak blood velocity (DPVr and DPVh). These paired data enable calculation of coronary flow velocity reserve (CFVR) and its inherent companion that is based on the quadratic mean: CFVRC = √{(DPVr)2 + (DPVh)2}. Additionally, basal and hyperemic coronary microvascular resistance (BMR and HMR) were estimated. A CFVR ≤2.5 was considered abnormal; the median value of DPVh (75 cm/s) and CFVRC (80 cm/s) were selected as cut-offs to classify patients.

Results

HT patients can be assigned to four groups, based on their CFVR and DPVh (Figure A): group 1 (n=32), discordant with preserved CFVR (3.1±0.4); group 2 (n=60), concordant with preserved CFVR (3.4±0.5); group 3 (n=31), concordant with impaired CFVR (1.8±0.3) and group 4 (n=11), discordant with impaired CFVR (2.0±0.2). Group 3 represents the structural microvascular remodeling with high HMR, while group 4 represents the functional remodeling with low BMR. Intriguingly, group 1 showed lower DPVr (p&lt;0.0001) and lower DPVh (p&lt;0.0001) than controls (Figure B, upper panel) with lower CFVR (p&lt;0.0001), even if normal, and lower CFVRC (p&lt;0.0001) than controls (Figure B, lower panel). Moreover, both BMR and HMR were higher in group 1 than in controls (5.3±1 vs 4.4±1.2, p=0.001 and 1.5±0.3 vs 1.1±0.2, p&lt;0.0001, respectively), suggesting structural microvascular remodeling. Conversely, group 2 was comparable with controls (Figure B). Clinical characteristics of the different groups are shown in the Table. 13/32 (40.6%) patients in group 1 died in a follow up of 28 years and mortality rate was comparable to group 3 (14/31, 45.2%). However, CFVRC was &lt;80 cm/s in all 13 deaths in group 1, yet being characterized by preserved CFVR (Figure C).

Conclusions

A normal CFVR could hide detection of microvascular damage with high flow resistance and low flow velocities at rest. This microvasculopathy seems to be secondary to factors unrelated to HT (i.e., less rejections and more often diabetes). Being a dimensionless ratio, CFVR may miss some deaths, yet captured by CFVRC. Thus, the combined use of CFVR and CFVRC provides more complete clinical information on coronary microvasculopathy in HT.

Funding Acknowledgement

Type of funding source: None

Sex-Specific Interpretation of Coronary Flow Reserve and Fractional Flow Reserve Metrics, Including Their Companions

BACKGROUND

Impairment of coronary flow is usually evaluated by considering the ratio of two measurements. Fractional flow reserve (FFR) estimates impact on an epicardial artery by taking mean post-stenotic pressure divided by mean aortic pressure, both obtained during adenosine induced hyperemia. Coronary flow reserve (CFR) compares hyperemic flow or velocity with the baseline situation, also as a ratio. As severity of underlying pathology may differ for men and women, we investigate the impact of these differences on relevant metrics.

METHODS

As sex associated differences may cancel out in a ratio, this weakness of a ratio can be compensated by analyzing the intrinsic companion (C) and consider polar coordinates. Thus, besides the familiar ratio based metrics, we also analyze FFRC and CFRC. Outcomes of in silico studies are employed to extrapolate actual patient data and predict consequences. For FFR 129 patients (38 women) were invasively studied using pressure wires. CFR was measured noninvasively for the left anterior descending coronary artery by recording ultrasound based Doppler velocity in 114 individuals (28 women).

RESULTS

The FFR can be identified as an indicator of the pressure gradient over the stenosis (R=-0.90), while FFRC differs for men compared to women (P=0.04) and correlates (R=0.93) with post-stenotic driving pressure. CFR shows a difference for men versus women (P=0.04) and is best associated with hyperemic flow (R=0.64), whereas CFRC relates to hyperemia recruited velocity (R=0.97). Simulation studies show that FFR may differ for both sexes when considering elderly.

CONCLUSIONS

Analysis of ratios require inclusion of the companion, and sex-specific differences deserve attention.

High Density Lipoproteins: Metabolism, Function, and Therapeutic Potential

High Density Lipoproteins (HDLs) have long been considered as “good cholesterol,” beneficial to the whole body and, in particular, to cardio-vascular health. However, HDLs are complex particles that undergoes dynamic remodeling through interactions with various enzymes and tissues throughout their life cycle, making the complete understanding of its functions and roles more complicated than initially expected. In this review, we explore the novel understanding of HDLs' behavior in health and disease as a multifaceted class of lipoprotein, with different size subclasses, molecular composition, receptor interactions, and functionality. Further, we report on emergent HDL-based therapeutics tested in small and larger scale clinical trials and their mixed successes.

Macrophage NCOR1 protects from atherosclerosis by repressing a pro-atherogenic PPARγ signature

AIMS

Nuclear receptors and their cofactors regulate key pathophysiological processes in atherosclerosis development. The transcriptional activity of these nuclear receptors is controlled by the nuclear receptor corepressors (NCOR), scaffolding proteins that form the basis of large corepressor complexes. Studies with primary macrophages demonstrated that the deletion of Ncor1 increases the expression of atherosclerotic molecules. However, the role of nuclear receptor corepressors in atherogenesis is unknown.

METHODS AND RESULTS

We generated myeloid cell-specific Ncor1 knockout mice and crossbred them with low-density lipoprotein receptor (Ldlr) knockouts to study the role of macrophage NCOR1 in atherosclerosis. We demonstrate that myeloid cell-specific deletion of nuclear receptor corepressor 1 (NCOR1) aggravates atherosclerosis development in mice. Macrophage Ncor1-deficiency leads to increased foam cell formation, enhanced expression of pro-inflammatory cytokines, and atherosclerotic lesions characterized by larger necrotic cores and thinner fibrous caps. The immunometabolic effects of NCOR1 are mediated via suppression of peroxisome proliferator-activated receptor gamma (PPARγ) target genes in mouse and human macrophages, which lead to an enhanced expression of the CD36 scavenger receptor and subsequent increase in oxidized low-density lipoprotein uptake in the absence of NCOR1. Interestingly, in human atherosclerotic plaques, the expression of NCOR1 is reduced whereas the PPARγ signature is increased, and this signature is more pronounced in ruptured compared with non-ruptured carotid plaques.

CONCLUSIONS

Our findings show that macrophage NCOR1 blocks the pro-atherogenic functions of PPARγ in atherosclerosis and suggest that stabilizing the NCOR1-PPARγ binding could be a promising strategy to block the pro-atherogenic functions of plaque macrophages and lesion progression in atherosclerotic patients.

P1941The nuclear receptor corepressor 1 blocks CD36-mediated foam cell formation in atherogenesis

Background

Nuclear receptors and their cofactors regulate the expression of various target genes in different tissue and organs to orchestrate downstream (patho)physiological processes. Although the function of several nuclear receptors in atherosclerosis has been studied, very little is known about the role of nuclear receptor cofactors in atherosclerosis. Given its important role to suppress inflammatory processes, we speculated that macrophage nuclear receptor corepressor 1 (NCOR1) plays a protective function in atherosclerosis development.

Purpose

To evaluate the contribution of macrophage NCOR1 in atherosclerosis we used myeloid cell-specific Ncor1 knockout mice on an atherosclerosis-prone background.

Methods and results

8-week-old male and female mice were exposed to a high high-cholesterol diet for 12 weeks. Our findings demonstrate that the lack of macrophage Ncor1 leads to a severe atherosclerotic phenotype in both sexes. These mice show a higher content of plaques along the thoraco-abdominal aortae as well as at the aortic sinus, which were characterized by larger necrotic cores and thinner fibrous caps, a typical signature of unstable plaques. Moreover, we found that the pro-atherogenic effects of the Ncor1 deletion are mediated via derepression of peroxisome proliferator-activated receptor gamma (PPARγ) target genes in mouse and human macrophages, especially the enhanced expression of the CD36 scavenger receptor and the subsequent rise in oxLDL uptake. Interestingly, while the expression of NCOR1 is reduced, the PPARγ signature is increased in human atherosclerotic plaques, and this signature is further pronounced in ruptured compared to stable carotid plaques.

Conclusion

Our findings suggest that macrophage NCOR1 blocks the pro-atherogenic functions of PPARγ in atherosclerosis and prevents the disease development.

Acknowledgement/Funding

The Swiss National Science Foundation, the Novartis Foundation, Olga-Mayenfisch Foundation, the OPO foundation

P724Antibody treatment against pathological pancreatic islet amyloid polypeptide (IAPP) aggregates restores endothelial dysfunction in human-IAPP transgenic rats

Background

Islet amyloid polypeptide (IAPP; or amylin) is produced in pancreatic B-cells and co-secreted with insulin in response to nutrients. In insulin resistance and type 2 diabetes (T2D), higher secretion and impaired processing of IAPP results in its aggregation, contributing to amyloid-induced apoptosis of pancreatic B-cells. Insight into IAPP's role in diabetic endothelial dysfunction is scarce.

Purpose

Rats transgenic for human IAPP (hIAPP), which in contrast to rodent IAPP produces amyloid deposits and contributes to diabetes due to B-cell failure, were studied to understand the mechanisms of endothelial dysfunction in T2D and test the vasoprotective actions of an anti-hIAPP antibody.

Methods

Male hemizygous transgenic Sprague-Dawley rats with islet B-cell expression of hIAPP (TG) and wild-type (WT) controls were sacrificed at 2, 3, 6- and 9-months age to assess endothelial function. In a second experiment, TG rats received weekly injections of antibody against aggregated hIAPP (3 mg/kg; TG-Ab) from 3–12 months of age; TG and WT controls received PBS. Oral glucose tolerance was assessed before harvesting. At the respective time points (12 mts in exp. 2), thoracic aortic rings were isolated and subjected to ex vivo isometric tension recording. After contraction with norepinephrine (NE 1x10–7 mol/L), cumulative relaxation responses were performed to glucagon-like peptide-1 (GLP-1; 10–12 to 10–6 mol/L) and insulin (10–11 to 10–6 mol/L). Pancreas and aortic arch samples were used for immunostaining of hIAPP antibody engagement.

Results

GLP-1 and insulin-mediated vasodilation was impaired in 3 month-old TG rats compared to WT. Glucose intolerance appeared in TG rats at 6 months in comparison to WT (p<0.0001), indicating that endothelial dysfunction in TG rats precedes the onset of glucose intolerance. Anti-hIAPP antibody showed selectivity against aggregated IAPP in pancreatic islets, but there was no target engagement in the aortic arch, questioning a pathogenic role of IAPP deposition in the aortic wall. At 12 months, glucose control in TG-Ab rats was improved in comparison to TG control rats (p<0.013). Vasodilatation in TG-Ab rats was restored in response to GLP-1 (35.5% ± 4.6 vs. 16.0% ± 3.1 in TG controls), similar to that of WT rats (35.5% ± 6.5). Vasodilatation in response to insulin (48.9% ± 4.2) was improved in comparison to both TG (29.4% ± 3.0) and WT controls (32.5% ± 5.7) (p<0.0001; 2-way ANOVA, n=6–11 for all groups.

Conclusion

Early endothelial dysfunction develops in hIAPP rats compared to WT. Endothelial dysfunction is restored by the anti-hIAPP antibody treatment via improved oral glucose tolerance, but it remains unclear whether this effect is due to a local action in the aorta or a secondary effect, e.g. due to a reduction in pancreatic IAPP deposition.

P729The functional relevance of bile acids in the improvement of HDL-mediated endothelial protection after bariatric surgery

Introduction

Roux-en-Y gastric bypass (RYGB) reduces cardiovascular mortality. We showed that high density lipoproteins (HDL)-mediated vasoprotection is improved early after RYGB. Circulating BAs increase upon RYGB and contribute to the weight-loss independent metabolic improvements after surgery. Bile acids (BA) are signaling molecules increasingly recognized as regulators of cardiometabolic homeostasis. BAs circulate in the blood either free or bound to albumin and HDL. The signaling role of HDL-bound BAs (HDL-BAs) is unknown. Indeed, HDL may facilitate BA delivery directly to endothelial cells where BA may synergize with HDL to promote vasoprotection.

Purpose

We studied whether RYGB changes the composition of HDL-BA and whether HDL functional properties may be modulated by specific BA bound to HDL.

Methods

HDL were isolated by ultracentrifugation from 29 morbidly obese patients before and 1 year after RYGB. The HDL-BA composition was determined by liquid chromatography-mass spectrometry (LC/MS-MS) and HDL vasoprotective properties were evaluated ex-vivo in human aortic endothelial cells (HAEC). The size and abundance of HDL particles were determined by NMR spectroscopy in plasma.

Results

The increase in total BA concentrations observed in plasma 1 year after RYGB also translated into higher concentrations (up to 25%) of BA bound to HDL. Moreover, obesity-induced HDL dysfunction was reversed after surgery, as shown by improved HDL-mediated endothelial NO production, anti-apoptotic effects and cholesterol efflux capacity. The size function analyses showed a post-operative shift towards larger HDL. After RYGB there was a remodeling of BA bound to HDL, which are either agonists of the endothelial nuclear farnesoid X receptor (FXR), e.g. chenodeoxy-CA (CDCA), cholic acid (CA) or for the membrane TGR5 receptor, e.g. deoxy-CA (DCA). The composition-function analysis revealed that among all BA subclasses, the specific enrichment in CA and in CDCA bound to HDL correlated with an improved endothelial anti-apoptotic capacity of HDL (R −0.52, p=0.006 for CA-HDL and R −0.35, p=0.07 for CDCA-HDL). Further, the exogenous loading of CA onto healthy native HDL isolated from human serum significantly enhanced their endothelial anti-apoptotic function. In the case of obese, dysfunctional, pro-apoptotic HDL, exogenous CA loading was able to restore HDL anti-apoptotic function.

Conclusion

Exogenous loading of CA restored HDL anti-apoptotic function of HDL from obese patients mimicking the beneficial remodeling of BA bound to HDL observed after RYGB. These results suggest a crucial interaction between endothelial cells and BA in the improvement of HDL's vasoprotective properties.

Acknowledgement/Funding

Swiss national Science Foundation Ambizione and PRIMA grant to EO

The crosstalk between the cardiovascular and the immune system

The heart and the immune system are highly integrated systems cross-talking through cytokines, hormones and neurotransmitters. Their balance can be altered by numerous physical or psychological stressors leading to the onset of inflammation, endothelial dysfunction and tissue damage. Here, we review the main players and mechanisms involved in the field. A new research paradigm, which considers also novel contributors, like endothelial cells, is needed to better understand the pathophysiology of immune-mediated cardiovascular disorders and beyond.

Quantification of intrathoracic fat adds prognostic value in women undergoing myocardial perfusion imaging

AIM

Amongst patients with coronary artery disease (CAD), women experience relatively worse outcomes as compared to men. Evidence to date has failed to explore unique female imaging targets as major determinants of cardiovascular risk. We sought to assess the prognostic value of epicardial (EFV) and intrathoracic fat volume (IFV) quantification in women and men with suspected and known CAD.

METHODS AND RESULTS

Intrathoracic fat volume and EFV were calculated from non-contrast CT and analyzed in a propensity-matched cohort of 190 patients (95 women, mean age 62.5 ± 11.3 years) undergoing myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) for evaluation of CAD. IFV and EFV were significantly lower in women as compared to men (198.2 ± 78.4 vs 293.2 ± 114.7 cm³ and 105.6 ± 48.9 vs 135.8 ± 60.9 cm³, p < 0.001) and showed a strong association with coronary artery calcium score (CACS) and obstructive CAD in women (p < 0.05), but not in men. Fat volumes were not related to abnormal MPI in either population (p = NS). During a median follow-up of 2.8 years, high IFV was associated with reduced event free survival (log rank = 0.019 vs low IFV) in women, but not in men. Accordingly, a multivariate Cox regression model adjusted for cardiovascular risk factors, CACS, CCTA, and MPI findings selected IFV as a significant predictor of major adverse cardiovascular events (MACE) in women (HR 1.32, 95%CI 1.18-1.55, p = 0.001).

CONCLUSION

Quantification of IFV provides incremental prognostic value for MACE in women, beyond that provided by traditional risk factors and imaging findings.

[Metabolism and Function of High-Density Lipoproteins (HDL)]

Metabolism and Function of High-Density Lipoproteins (HDL) Abstract. HDL has long been considered as 'good cholesterol', beneficial to the whole body and in particular to cardio-vascular health. However, HDL is a complex particle that undergoes dynamic remodeling through interactions with various enzymes and tissue types throughout its life cycle. In this review, we explore the novel understanding of HDL as a multifaceted class of lipoprotein, with multiple subclasses of different size, molecular composition, receptor interactions, and functionality, in health and disease. Further, we report on emergent HDL based therapeutics tested in small and larger scale clinical trials and their mixed successes.

Heart Transplantation Survival and Sex-Related Differences

Orthotopic heart transplantation (OHT) is the "gold standard" treatment for patients with end-stage heart failure, with approximately 5000 transplants performed each year worldwide. Heart transplantation survival rates have progressively improved at all time points, despite an increase in donor and recipient age and comorbidity and greater recipient urgency; according to the registry of the International Society of Heart and Lung Transplantation (ISHLT), the median survival of patients posttransplantation is currently 12.2 years.Long-term survival is sub-optimal, and outcomes after OHT remain constrained by the development of acute rejection and cardiac allograft vasculopathy (CAV). Moreover, donor organs are in short supply, making optimal organ utilization an ongoing priority. For these reasons, substantial interest continues to exist in identifying factors portending increased survival and improved organ utilization.

Women and Men in the History of Western Cardiology: Some Notes on Their Position as Patients, Role as Investigational Study Subjects, and Impact as Professionals

Nowadays, it is generally appreciated that studies in the medical field should not only include sex-related aspects but also consider age. In the past, taking the era of Hippocrates as a starting point for the Western medical sciences, such aspects were less urgent and barely relevant. However, considering such details during daily life became increasingly important as the traditional roles of men and women in society and household converged. In the Western world, this fundamental transition process started recently and is advancing at an accelerated pace. Research about the role of women has also evolved, starting from plain history about the lives of women to a description of the relation between men and women, resulting in the gender concept. The present survey highlights a historical selection of observations referring to the impact of men and women on the medical sciences, as patient, study object, and professional. Whenever relevant, focus will be on the field of cardiovascular investigations as documented in the Western world. Rather than being exhaustive, we focus on a few remarkable icons, including Trota of Salerno, Hildegard von Bingen, and Miguel Serveto.

The Heart as a Psychoneuroendocrine and Immunoregulatory Organ

The heart can be viewed not just as muscle pump but also as an important checkpoint for a complex network of nervous, endocrine, and immune signals. The heart is able to process neurological signals independently from the brain and to crosstalk with the endocrine and immune systems. The heart communicates with the psyche through the neuro-endocrine-immune system in a highly integrated way, in order to maintain the homeostasis of the whole body with peculiarities specific to males and females.

Inhibition of Vascular c-Jun N-Terminal Kinase 2 Improves Obesity-Induced Endothelial Dysfunction After Roux-en-Y Gastric Bypass

Background

Roux‐en‐Y gastric bypass (RYGB) reduces obesity‐associated comorbidities and cardiovascular mortality. RYGB improves endothelial dysfunction, reducing c‐Jun N‐terminal kinase (JNK) vascular phosphorylation. JNK activation links obesity with insulin resistance and endothelial dysfunction. Herein, we examined whether JNK1 or JNK2 mediates obesity‐induced endothelial dysfunction and if pharmacological JNK inhibition can mimic RYGB vascular benefits.

Methods and Results

After 7 weeks of a high‐fat high‐cholesterol diet, obese rats underwent RYGB or sham surgery; sham–operated ad libitum–fed rats received, for 8 days, either the control peptide D‐TAT or the JNK peptide inhibitor D‐JNKi‐1 (20 mg/kg per day subcutaneous). JNK peptide inhibitor D‐JNKi‐1 treatment improved endothelial vasorelaxation in response to insulin and glucagon‐like peptide‐1, as observed after RYGB. Obesity increased aortic phosphorylation of JNK2, but not of JNK1. RYGB and JNK peptide inhibitor D‐JNKi‐1 treatment blunted aortic JNK2 phosphorylation via activation of glucagon‐like peptide‐1–mediated signaling. The inhibitory phosphorylation of insulin receptor substrate‐1 was reduced, whereas the protein kinase B/endothelial NO synthase pathway was increased and oxidative stress was decreased, resulting in improved vascular NO bioavailability.

Conclusions

Decreased aortic JNK2 phosphorylation after RYGB rapidly improves obesity‐induced endothelial dysfunction. Pharmacological JNK inhibition mimics the endothelial protective effects of RYGB. These findings highlight the therapeutic potential of novel strategies targeting vascular JNK2 against the severe cardiovascular disease associated with obesity.

Laparoscopic Roux-en-Y gastric bypass versus laparoscopic mini gastric bypass in the treatment of obesity: study protocol for a randomized controlled trial

Background

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is considered the gold standard in bariatric surgery, achieving durable long-term weight loss with improvement of obesity-related comorbidities. Lately, the laparoscopic mini gastric bypass (LMGB) has gained worldwide popularity with similar results to LRYGB in terms of weight loss and comorbidity resolution. However, there is a lack of randomized controlled trials (RCT) comparing LMGB and LRYGB. This article describes the design and protocol of a randomized controlled trial comparing the outcomes of these two bariatric procedures.

Methods/Design

The trial is designed as a single center, randomized, patient and observer blinded trial. The relevant ethics committee has approved the trial protocol. To demonstrate that LMGB is not inferior to LRYGB in terms of excess weight loss (EWL) the study is conducted as a non-inferiority trial with the sample-size calculations performed accordingly. EWL 12 months after surgery is the primary endpoint, whereas 3-year EWL, morbidity, mortality, remission of obesity related comorbidities, quality of life (QOL) and hormonal and lipid profile changes are secondary endpoints. Eighty patients, 18 years or older and with a body mass index (BMI) between 35 and 50 kg/m² who meet the Swiss guidelines for the surgical treatment of morbid obesity will be randomized. The endpoints and baseline measurements will be assessed pre-surgery, peri-surgery and post-surgery (fixed follow up measurements are at discharge and at the time points 6 weeks and 12 and 36 months postoperatively).

Discussion

With its 3-year follow up time, this RCT will provide important data on the impact of LMGB and LRYGB on EWL, remission of comorbidities, QOL and hormonal and lipid profile changes.

Trial registration

ClinicalTrials.gov, NCT02601092. Registered on 28 September 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1957-9) contains supplementary material, which is available to authorized users.