Role of the Nuclear Receptor Corepressor 1 (NCOR1) in Atherosclerosis and Associated Immunometabolic Diseases

Atherosclerotic cardiovascular disease is part of chronic immunometabolic disorders such as type 2 diabetes and nonalcoholic fatty liver disease. Their common risk factors comprise hypertension, insulin resistance, visceral obesity, and dyslipidemias, such as hypercholesterolemia and hypertriglyceridemia, which are part of the metabolic syndrome. Immunometabolic diseases include chronic pathologies that are affected by both metabolic and inflammatory triggers and mediators. Important and challenging questions in this context are to reveal how metabolic triggers and their downstream signaling affect inflammatory processes and vice-versa. Along these lines, specific nuclear receptors sense changes in lipid metabolism and in turn induce downstream inflammatory and metabolic processes. The transcriptional activity of these nuclear receptors is regulated by the nuclear receptor corepressors (NCORs), including NCOR1. In this review we describe the function of NCOR1 as a central immunometabolic regulator and focus on its role in atherosclerosis and associated immunometabolic diseases.

Prognostic values of fasting hyperglycaemia in non-diabetic patients with acute coronary syndrome: A prospective cohort study

Background:

Controversy remains regarding the prevalence of hyperglycaemia in non-diabetic patients hospitalised with acute coronary syndrome and its prognostic value for long-term outcomes.

Methods and results:

We evaluated the prevalence of hyperglycaemia (defined as fasting glycaemia ⩾10 mmol/l) among patients with no known diabetes at the time of enrolment in the prospective Special Program University Medicine-Acute Coronary Syndromes cohort, as well as its impact on all-cause death, myocardial infarction, stroke and incidence of diabetes at one year. Among 3858 acute coronary syndrome patients enrolled between December 2009–December 2014, 709 (18.4%) had known diabetes, while 112 (3.6%) of non-diabetic patients had hyperglycaemia at admission. Compared with non-hyperglycaemic patients, hyperglycaemic individuals were more likely to present with ST-elevation myocardial infarction and acute heart failure. At discharge, hyperglycaemic patients were more frequently treated with glucose-lowering agents (8.9% vs 0.66%, p<0.001). At one-year, adjudicated all-cause death was significantly higher in non-diabetic patients presenting with hyperglycaemia compared with patients with no hyperglycaemia (5.4% vs 2.2%, p=0.041) and hyperglycaemia was a significant predictor of one-year mortality (adjusted hazard ratio 2.39, 95% confidence interval 1.03–5.56). Among patients with hyperglycaemia, 9.8% had developed diabetes at one-year, while the corresponding proportion among patients without hyperglycaemia was 1.8% (p<0.001). In multivariate analysis, hyperglycaemia at presentation predicted the onset of treated diabetes at one-year (odds ratio 4.15, 95% confidence interval 1.59–10.86; p=0.004).

Conclusion:

Among non-diabetic patients hospitalised with acute coronary syndrome, a fasting hyperglycaemia of ⩾10 mmol/l predicted one-year mortality and was associated with a four-fold increased risk of developing diabetes at one year.

Obesity-induced activation of JunD promotes myocardial lipid accumulation and metabolic cardiomyopathy

AIMS

Metabolic cardiomyopathy (MC)-characterized by intra-myocardial triglyceride (TG) accumulation and lipotoxic damage-is an emerging cause of heart failure in obese patients. Yet, its mechanisms remain poorly understood. The Activator Protein 1 (AP-1) member JunD was recently identified as a key modulator of hepatic lipid metabolism in obese mice. The present study investigates the role of JunD in obesity-induced MC.

METHODS AND RESULTS

JunD transcriptional activity was increased in hearts from diet-induced obese (DIO) mice and was associated with myocardial TG accumulation and left ventricular (LV) dysfunction. Obese mice lacking JunD were protected against MC. In DIO hearts, JunD directly binds PPARγ promoter thus enabling transcription of genes involved in TG synthesis, uptake, hydrolysis, and storage (i.e. Fas, Cd36, Lpl, Plin5). Cardiac-specific overexpression of JunD in lean mice led to PPARγ activation, cardiac steatosis, and dysfunction, thereby mimicking the MC phenotype. In DIO hearts as well as in neonatal rat ventricular myocytes exposed to palmitic acid, Ago2 immunoprecipitation, and luciferase assays revealed JunD as a direct target of miR-494-3p. Indeed, miR-494-3p was down-regulated in hearts from obese mice, while its overexpression prevented lipotoxic damage by suppressing JunD/PPARγ signalling. JunD and miR-494-3p were also dysregulated in myocardial specimens from obese patients as compared with non-obese controls, and correlated with myocardial TG content, expression of PPARγ-dependent genes, and echocardiographic indices of LV dysfunction.

CONCLUSION

miR-494-3p/JunD is a novel molecular axis involved in obesity-related MC. These results pave the way for approaches to prevent or treat LV dysfunction in obese patients.

Eligibility for PCSK9 inhibitors based on the 2019 ESC/EAS and 2018 ACC/AHA guidelines

AIMS

The 2018 American College of Cardiology (ACC)/American Heart Association (AHA) and 2019 European Society of Cardiology (ESC)/European Atherosclerosis Society (EAS) lipid guidelines recently updated their recommendations regarding proprotein convertase subtilisin/kexin-9 inhibitors (PCSK9i). We assessed the potential eligibility for PCSK9i according to the new guidelines in patients with acute coronary syndromes.

METHODS AND RESULTS

We analysed a contemporary, prospective Swiss cohort of patients hospitalised for acute coronary syndromes. We modelled a statin intensification effect and an incremental ezetimibe effect on low-density lipoprotein-cholesterol levels among patients who were not on high-intensity statins or ezetimibe. One year after the index acute coronary syndrome event, treatment eligibility for PCSK9i was defined as low-density lipoprotein-cholesterol of 1.4 mmol/l or greater according to ESC/EAS guidelines. For ACC/AHA guidelines, treatment eligibility was defined as low-density lipoprotein-cholesterol of 1.8 mmol/l or greater in the presence of very high-risk atherosclerotic cardiovascular disease, defined by multiple major atherosclerotic cardiovascular disease events and/or high-risk conditions. Of 2521 patients, 93.2% were treated with statins (53% high-intensity statins) and 7.3% with ezetimibe at 1 year, and 54.9% had very high-risk atherosclerotic cardiovascular disease. Low-density lipoprotein-cholesterol levels less than 1.8 mmol/l and less than 1.4 mmol/l at 1 year were observed in 37.5% and 15.7% of patients, respectively. After modelling the statin intensification and ezetimibe effects, these numbers increased to 76.1% and 49%, respectively. The proportion of patients eligible for PCSK9i was 51% according to ESC/EAS criteria versus 14% according to ACC/AHA criteria.

CONCLUSIONS

In this analysis, the 2019 ESC/EAS guidelines rendered half of all post-acute coronary syndrome patients potentially eligible for PCSK9i treatment, as compared to a three-fold lower eligibility rate based on the 2018 ACC/AHA guidelines.

Clinical predictors of left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy

AIM

The impact of clinical characteristics for predicting patterns of ventricular involvement in arrhythmogenic right ventricular cardiomyopathy (ARVC) are not well defined. The aims of this study were to characterize different patterns of ventricular involvement in patients with ARVC and to stratify them based on clinical characteristics exercise and underlying genetic mutations.

METHODS

Sixty-four patients with definite ARVC from the Swiss ARVC Registry were enrolled. Right and left ventricular functions were assessed at baseline and most recent follow-up. All patients received genetic testing. Serum high-sensitivity cardiac Troponin T (hs-cTNT) and N-terminal of pro-brain natriuretic peptide (NT-proBNP) were determined at baseline.

RESULTS

Thirty-five patients (55%) had isolated right ventricular (RV) involvement, 12 patients (19%) had biventricular (BiV) involvement at baseline and 17 patients (26%) had no left ventricular (LV) involvement at baseline, but revealed new onset LV involvement at mean follow-up of 7.5 years. Patients with BiV involvement at baseline harbored significantly more desmoplakin and multiple mutations and patients with new-onset LV involvement at follow-up frequently showed non-desmosomal mutations. Patients engaging in competitive sports more often showed LV involvement during follow-up. Baseline hs-cTNT and NT-proBNP levels were higher in patients developing BiV involvement.

CONCLUSION

Multiple mutations are more common in ARVC patients with BiV involvement. Competitive exercise is associated with disease progression resulting in BiV involvement. Hs-cTNT and NT-proBNP are elevated in patients with BiV involvement and may help to identify ARVC patients at risk for developing BiV disease.

Comparison of P2Y12 receptor inhibitors in patients with ST-elevation myocardial infarction in clinical practice: a propensity score analysis of five contemporary European registries

Aims

Among acute coronary syndromes (ACS), ST-segment elevation myocardial infarction (STEMI) has the most severe early clinical course. Recent randomized clinical trials have demonstrated that novel antithrombotic therapies improve in-hospital outcomes in STEMI patients. We aimed to describe the effectiveness and safety of P₂Y₁₂ receptor inhibitors in clinical practice in patients with STEMI based on data from contemporary European ACS registries.

Methods and results

Five registries from the PIRAEUS initiative (AAPCI/ADPAT, ALKK-PIC, AMIS Plus, Belgium STEMI, and EYESHOT) provided data for the assessment of P₂Y₁₂ receptor inhibitor-based dual antiplatelet therapy. Registries were heterogeneous in terms of setting, patient characteristics, and treatment selection. Matched pair analysis and propensity score matching were used to assess all-cause in-hospital death rates based on data from 25 250 patients (8577 patients on prasugrel, 5995 on ticagrelor, and 10 678 on clopidogrel). The odds ratio (OR) for the death of any cause when compared with clopidogrel was 0.72 [95% confidence interval (CI) 0.62–0.84, P < 0.001] in favour of the new P₂Y₁₂ receptor inhibitors (prasugrel and ticagrelor combined). In the comparison between prasugrel and ticagrelor, there were no relevant differences (OR 0.97, 95% CI 0.77–1.23; P = 0.81). Event rates of cardiovascular death and stroke were also substantially lower for the new P₂Y₁₂ receptor inhibitors. The differences between clopidogrel and prasugrel or ticagrelor on major bleeding were numerically in the same order as for death of any cause but were not statistically significant. No differences in ischaemic and bleeding outcomes were observed between prasugrel and ticagrelor.

Conclusion

This analysis suggests that the prasugrel or ticagrelor compared with clopidogrel have favourable outcomes in clinical practice while not being inferior in terms of safety.

Sirt6 deletion in bone marrow-derived cells increases atherosclerosis - Central role of macrophage scavenger receptor 1

AIMS

Sirtuin 6 (Sirt6) is a NAD⁺-dependent deacetylase that plays a key role in DNA repair, inflammation and lipid regulation. Sirt6-null mice show severe metabolic defects and accelerated aging. Macrophage-foam cell formation via scavenger receptors is a key step in atherogenesis. We determined the effects of bone marrow-restricted Sirt6 deletion on foam cell formation and atherogenesis using a mouse model.

METHODS AND RESULTS

Sirt6 deletion in bone marrow-derived cells increased aortic plaques, lipid content and macrophage numbers in recipient Apoe^-/- mice fed a high-cholesterol diet for 12 weeks (n = 12-14, p < .001). In RAW macrophages, Sirt6 overexpression reduced oxidized low-density lipoprotein (oxLDL) uptake, Sirt6 knockdown enhanced it and increased mRNA and protein levels of macrophage scavenger receptor 1 (Msr1), whereas levels of other oxLDL uptake and efflux transporters remained unchanged. Similarly, in human primary macrophages, Sirt6 knockdown increased MSR1 protein levels and oxLDL uptake. Double knockdown of Sirt6 and Msr1 abolished the increase in oxLDL uptake observed upon Sirt6 single knockdown. FACS analyses of macrophages from aortic plaques of Sirt6-deficient bone marrow-transplanted mice showed increased MSR1 protein expression. Double knockdown of Sirt6 and the transcription factor c-Myc in RAW cells abolished the increase in Msr1 mRNA and protein levels; c-Myc overexpression increased Msr1 mRNA and protein levels.

CONCLUSIONS

Loss of Sirt6 in bone marrow-derived cells is proatherogenic; hereby macrophages play an important role given a c-Myc-dependent increase in MSR1 protein expression and an enhanced oxLDL uptake in human and murine macrophages. These findings assign endogenous SIRT6 in macrophages an important atheroprotective role.

Cardiomyocyte-Specific JunD Overexpression Increases Infarct Size following Ischemia/Reperfusion Cardiac Injury by Downregulating Sirt3

Ischemia/reperfusion (I/R) injury in acute myocardial infarction activates several deleterious molecular mechanisms. The transcription factor JunD regulates pathways involved in oxidative stress as well as in cellular proliferation, differentiation, and death. The present study investigated the potential role of JunD as a modulator of myocardial injury pathways in a mouse model of cardiac I/R injury. Infarct size, systemic and local inflammation, and production of reactive oxygen species, as well as cytosolic and mitochondrial apoptotic pathways were investigated in adult males after myocardial I/R. In wild-type (WT) mice, 30 minutes after ischemia and up to 24 hours following reperfusion, cardiac JunD messenger ribonucleic acid expression was reduced while JunB increased. Cardiac-specific JunD overexpressing mice (JunDTg/0 ) displayed larger infarcts compared with WT. However, postischemic inflammatory or oxidative responses did not differ. JunD overexpression reduced Sirt3 transcription by binding to its promoter, thus leading to mitochondrial dysfunction, myocardial cell death, and increased infarct size. On the other hand, JunD silencing reduced, while Sirt3 silencing increased infarct size. In human myocardial autopsy specimens, JunD-positive areas within the infarcted left ventricle staining corresponded to undetectable Sirt3 areas in consecutive sections of the same heart. Cardiac-specific JunD overexpression increases myocardial infarct size following I/R. These effects are mediated via Sirt3 transcriptional repression, mitochondrial swelling, and increased apoptosis, suggesting that JunD is a key regulator of myocardial I/R injury. The present data set the stage for further investigation of the potential role of Sirt3 activation as a novel target for the treatment of acute myocardial infarction.

Deleterious role of endothelial lectin-like oxidized low-density lipoprotein receptor-1 in ischaemia/reperfusion cerebral injury

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is implicated in cardiovascular disease by modulating apoptosis and oxidative stress. We hypothesized that LOX-1 may be involved in pathophysiology of stroke by mediating ischaemia/reperfusion (I/R)-dependent cell death. Transient middle cerebral artery occlusion (tMCAO) was performed in wild-type (WT) mice, endothelial-specific LOX-1 transgenic mice (eLOX-1TG) and WT animals treated with LOX-1 silencing RNA (siRNA). In WT mice exposed to tMCAO, LOX-1 expression and function were increased in the MCA. Compared to WT animals, eLOX-1TG mice displayed increased stroke volumes and worsened outcome after I/R. Conversely, LOX-1-silencing decreased both stroke volume and neurological impairment. Similarly, in HBMVECs, hypoxia/reoxygenation increased LOX-1 expression, while LOX-1 overexpressing cells showed increased death following hypoxia reoxygenation. Increased caspase-3 activation was observed following LOX-1 overexpression both in vivo and in vitro, thus representing a likely mediator. Finally, monocytes from ischaemic stroke patients exhibited increased LOX-1 expression which also correlated with disease severity. Our data unequivocally demonstrate a key role for LOX-1 in determining outcome following I/R brain damage. Our findings could be corroborated in human brain endothelial cells and monocytes from patients, underscoring their translational relevance and suggesting siRNA-mediated LOX-1 knockdown as a novel therapeutic strategy for stroke patients.

Diabetes and baseline glucose are associated with inflammation, left ventricular function and short- and long-term outcome in acute coronary syndromes: role of the novel biomarker Cyr 61

Background

Hyperglycemia in the setting of an acute coronary syndrome (ACS) impacts short term outcomes, but little is known about longer term effects. We therefore designed this study to firstly determine the association between hyperglycemia and short term and longer term outcomes in patients presenting with ACS and secondly evaluate the prognostic role of diabetes, body mass index (BMI) and the novel biomarker Cyr61 on outcomes.

Methods

The prospective Special Program University Medicine-Acute Coronary Syndrome (SPUM-ACS) cohort enrolled 2168 patients with ACS between December 2009 and October 2012, of which 2034 underwent PCI (93.8%). Patients were followed up for 12 months. Events were independently adjudicated by three experienced cardiologists. Participants were recruited from four tertiary hospitals in Switzerland: Zurich, Geneva, Lausanne and Bern. Participants presenting with acute coronary syndromes and who underwent coronary angiography were included in the analysis. Patients were grouped according to history of diabetes (or HbA1c greater than 6%), baseline blood sugar level (BSL; < 6, 6–11.1 and > 11.1 mmol/L) and body mass index (BMI). The primary outcome was major adverse cardiac events (MACE) which was a composite of myocardial infarction, stroke and all-cause death. Secondary outcomes included the individual components of the primary endpoint, revascularisations, bleeding events (BARC classification) and cerebrovascular events (ischaemic or haemorrhagic stroke or TIA).

Results

Patients with hyperglycemia, i.e. BSL ≥ 11.1 mmol/L, had higher levels of C-reactive protein (CRP), white blood cell count (WBC), creatinine kinase (CK), higher heart rates and lower left ventricular ejection fraction (LVEF) and increased N-terminal pro-brain natriuretic peptide. At 30 days and 12 months, those with BSL ≥ 11.1 mmol/L had more MACE and death compared to those with BSL < 6.0 mmol/L or 6.0–11.1 mmol/L (HR-ratio 4.78 and 6.6; p < 0.001). The novel biomarker Cyr61 strongly associated with high BSL and STEMI and was independently associated with 1 year outcomes (HR 2.22; 95% CI 1.33–3.72; Tertile 3 vs. Tertile 1).

Conclusions and relevance

In this large, prospective, independently adjudicated cohort of in all comers ACS patients undergoing PCI, both a history of diabetes and elevated entry glucose was associated with inflammation and increased risk of MACE both at short and long-term. The mediators might involve increased sympathetic activation, inflammation and ischemia as reflected by elevated Cyr61 levels leading to larger levels of troponin and lower LVEF.

Trial registration Clinical Trial Registration Number: NCT01000701. Registered October 23, 2009

P1222Intensification of lipid lowering therapy before and after publication of the IMPROVE-IT trial: A temporal analysis from the SPUM-ACS cohort

Background

The gradual implementation of evidence-based treatment strategies has improved outcomes in patients with acute coronary syndromes (ACS). The Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) was published on June 3rd, 2015, but its relevance on real life practice has not been explored.

Methods

We analyzed a prospective Swiss cohort of 6266 patients hospitalized for ACS between 2009 and 2017. The primary endpoints were the ezetimibe use overall or in combination with high-intensity statin at discharge and at one year after ACS. Secondary endpoint was LDL-C target achievement at one year in a subsample of 2984 patients. Relative Ratios (RR) were used to assess changes in primary endpoints before and after the publication of IMPROVE-IT, adjusting for age, sex, pre-existing diabetes, history of myocardial infarction, baseline low-density lipoprotein cholesterol (LDL-C) and attendance to cardiac rehabilitation.

Results

The period following the publication of the IMPROVE-IT trial was associated with an overall increase in the use of ezetimibe at discharge (from 1.8% to 3.8%, P<0.001, adjusted RR 2.85, 95% CI 1.90–4.25) and at one year (from 5.0% to 13.8%, P<0.001, adjusted RR 3.00, 95% CI 2.40–3.75). Before IMPROVE-IT trial, ezetimibe use at one year was stable around 5%, then steadily increased after its publication until 20% for patients included in 2017. The combination of high-intensity statin and ezetimibe increased from 0.9% to 2.1% at discharge (P<0.001, adjusted RR 3.35, 95% CI 1.90–5.89) and from 2.1% to 7.8% at one year (P<0.001, adjusted RR 3.98, 95% CI 2.90–5.47). The period following the publication of the IMPROVE-IT trial was associated with an improvement of LDL-C target <1.8 mmol/L (adjusted RR 1.37, 95% CI 1.12–1.68).

Conclusion

After the publication of the IMPROVE-IT trial, the use of ezetimibe was increased by three-fold in a large contemporary cohort of ACS patients, concomitant with an improved LDL-C target achievement.

P6440The perils of polyvascular disease with concomitant type 2 diabetes in a real-world cohort of patients with acute coronary syndrome

Background

Despite substantial improvement in type 2 diabetes (DM2) care, the burden of recurrent cardiovascular (CV) events remains high. Polyvascular disease (PVD), has recently emerged as a potential marker of heightened residual ischemic risk in DM2 patients, that are likely to derive a greater absolute risk reduction from more intense, individualized therapy.

Purpose

We sought to assess the relationship between DM2, PVD and CV outcomes among 2,168 all-comers patients admitted to four Swiss University Hospital for acute coronary syndrome (ACS) and enrolled in the prospective multicenter SPUM registry (NCT 01000701).

Methods

PVD was defined as concomitant peripheral artery disease, stroke or transient ischemic attack, or both. The composite primary endpoint was major adverse cardiac and cerebrovascular events (MACCE: Stroke, myocardial infarction, CV death). Adjusted Cox proportional hazards regression models were implemented to determine the risk associated with PVD disease in DM2 and outcomes, and intention-to-treat analysis was performed.

Results

Out of 2,168 ACS patients, 396 patients (18.3%) had DM2; of these 62 (15%) had PVD. Despite compared with the general ACS population, those with PVD + DM2 were more likely to have a complex history of CV disease, such as previous MI (27.4% vs 14.7%, p=0.021), prior percutaneous (37.1% vs 17%, p<0.001) or surgical (24.2% vs 5.1%, p<0.001) coronary revascularization, one third was not on statin therapy. At 1 year, patients with PVD + DM2 had a higher rate of MACCE compared to those presenting with PVD or DM2 alone. Rates of the single components of the primary endpoint and all-cause of death were all significantly higher in patients with PVD + DM2 vs. PVD or DM2 alone (Fig. 1A, all p<0.001). This enhanced risk persisted after adjustment for significant baseline differences, with a 34% (Adj. HR 1.34, 95% CI 1.15–1.49, p=0.02) increase in MACCE and a 44% increment of all cause of death (Adj. HR 1.44, 95% CI 1.06–1.54, p=0.02, Fig. 1B).

Outcomes by PVD and DM2 status.

Conclusions

Among a real-world cohort of ACS-patients, the coexistence of PVD and DM2 highlights the highest CV risk phenotype, being associated with significant increased rates of MACCE and all-cause of death. These observations might help clinicians to furtherly stratify the very high risk population and to identify patients who may derive the greatest benefit from more intense secondary prevention therapies.

P715Deletion of fibroblast activation protein decreases experimental atherosclerotic plaque formation and vulnerability

Background

Fibroblast activation protein (FAP) is a serine protease that is upregulated in sites of tissue remodeling, including arthritis, tumors and atherosclerosis. We have reported that FAP degrades type I collagen in human thin-cap fibroatheromata; its expression is enhanced in advanced human plaques and induced by inflammation. However, the role of endogenous FAP in atherosclerosis remains unknown.

Purpose

To investigate the effects of constitutive Fap loss-of-function on atherosclerotic plaque formation and vulnerability.

Methods and results

Male 8-week-old Apoe−/− Fap+/+ and Apoe−/− Fap−/− mice were fed a high-cholesterol diet (1.25% chol) for 12 weeks. En face analyses of thoracoabdominal aortae using Oil Red O (ORO) revealed decreased plaques in Apoe−/− Fap−/− mice (5.7±0.5%; n=21) compared to Apoe−/− Fap+/+ mice (10.7±0.7%; n=24; p<0.0001). In parallel, ORO analyses of serial aortic root cross sections showed diminished plaques in Fap-deficient mice (18.4±3.4% vs 27.6±2.1%). As a surrogate of plaque vulnerability, fibrous cap thickness was increased in Apoe−/− Fap−/− mice (65±6 mm vs 35±3 mm; p<0.01), whereas necrotic core size, plaque macrophages (CD68) and T cells (CD3) accumulation, as well as VCAM1 expression did not differ. These changes were independent of plasma triglycerides, total and LDL-cholesterol levels. Plasma of Fap-deficient mice showed decreased FAP activity compared to Fap wildtype controls. Notably, second harmonics generation in cross sections of aortic root plaques showed that the deposition and density of fibrillar collagens was enhanced in Fap-deficient (25.5±4.4%) compared to control plaques (13.8±2.5%; p<0.05). Consistently, Fap deletion led to an accumulation of uncleaved pre-COL3A1, a proteolytic target of FAP.

Conclusions

Constitutive Fap deletion decreases experimental atherosclerosis and features of plaque vulnerability. Thus, inhibition of FAP expression or activity may be a promising therapeutic target in atherosclerosis.

Acknowledgement/Funding

Swiss National Science Foundation, Swiss Heart Foundation

2287Endothelial SIRT6 exerts a beneficial role in cerebral ischemia/reperfusion injury by preserving blood-brain barrier integrity

Introduction

Stroke is a major cause of mortality and morbidity worldwide. Yet, therapeutic strategies are limited to the early reperfusion which can, on the other hand, worsen the brain damage trough ischemia/reperfusion (I/R) injury. Post-stroke blood-brain barrier (BBB) impairment is associated with worsened outcome. Aging is a major risk factor for stroke and genes regulating lifespan also contribute to the determination of cerebral damage during I/R injury.

Purpose

Given the pivotal role of endothelial cells in BBB, we hypothesized that the endothelial-specific expression of the longevity gene SIRT6 may protect the BBB from ischemia/reperfusion damage thus having a beneficial role on stroke outcome.

Methods

Endothelial-specific SIRT6 knockout (eSIRT6−/−) mice and control littermates (CTRL) underwent transient middle cerebral artery occlusion (tMCAO) for 45 min followed by 48 hours of reperfusion. Immunohistochemistry (IHC) was used to investigate BBB permeability by IgG extravasation and molecular mechanisms. Primary human brain microvascular endothelial cells (HBMVECs) transfected with either SIRT6 (siSIRT6) or scrambled (siSCR) small interfering RNA were subjected to hypoxia/reoxygenation (H/R). An in vitro BBB model consisting of a monolayer of siRNA-treated HBMVECs was established and barrier function was assessed by 48 h-lasting transendothelial electrical resistance measurement. SIRT6 expression in monocytes from stroke patients was correlated with the short-term neurological outcome [ΔNIHSS% = (NIHSS discharge-NIHSS admission)/ NIHSS admission*100].

Results

eSIRT6−/− displayed higher infarct volumes and lower survival rate compared to WT mice 48 h after tMCAO. The increased infarct volume was functionally relevant as eSIRT6−/− also showed worse post-stroke neurological impairment. Analysis of brain sections revealed increased BBB damage and increased endothelial expression of cleaved caspase-3 in eSIRT6−/− as compared to control littermates. In vitro, H/R reduced SIRT6 expression in HBMVECs. Mirroring the animal results, SIRT6 silencing impaired the barrier function of HBMVECs 48 h after exposure to H/R. In line with this, SIRT6-silenced HBMVECs showed reduced viability, increased cleaved caspase-3 expression and reduced activation of the anti-apoptotic survival pathway Akt as compared to control cells after H/R. The direct interaction between SIRT6 and Akt was confirmed by co-immunoprecipitation. In ischemic stroke patients, SIRT6 expression was higher in those with short-term neurological improvement (ΔNIHSS% >0) and negatively correlated with ΔNIHSS%.

Conclusion

Endothelial SIRT6 exerts a beneficial role in ischemic stroke by blunting I/R-mediated BBB damage. Specifically, SIRT6 reduces endothelial I/R-induced apoptotic death through activation of the protective Akt pathway. The longevity gene SIRT6 may represent a novel therapeutic target for the treatment of ischemic stroke.

Acknowledgement/Funding

Swiss National Science Foundation

Risk stratification of elderly patients with acute pulmonary embolism

BACKGROUND

Combining high-sensitivity cardiac Troponin T (hs-cTnT), NT-pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) may improve risk stratification of patients with pulmonary embolism (PE) beyond the PESI risk score.

METHODS

In the prospective multicentre SWITCO65+ study, we analysed 214 patients ≥ 65 years with a new submassive PE. Biomarkers and clinical information for the PESI risk score were ascertained within 1 day after diagnosis. Associations of hs-TnT, NT-proBNP, hs-CRP and the PESI risk score with the primary endpoint defined as 6-month mortality were assessed. The discriminative power of the PESI risk score and its combination with hs-cTnT, NT-proBNP and hs-CRP for 6-month mortality was compared using integrated discrimination improvement (IDI) index and net reclassification improvement (NRI).

RESULTS

Compared with the lowest quartile, patients in the highest quartile had a higher risk of death during the first 6 months for hs-cTnT (adjusted HR 10.22; 95% CI 1.79-58.34; P = 0.009) and a trend for NT-proBNP (adjusted HR 4.3; 95% CI 0.9-20.41; P = 0.067) unlike hs-CRP (adjusted HR 1.97; 95% CI 0.48-8.05; P = 0.344). The PESI risk score (c-statistic 0.77 (95% CI 0.69-0.84) had the highest prognostic accuracy for 6-month mortality, outperforming hs-cTnT, NT-proBNP and hs-CRP (c-statistics of 0.72, 0.72, and 0.54), respectively. Combining all three biomarkers had no clinically relevant impact on risk stratification when added to the PESI risk score (IDI = 0.067; 95% CI 0.012-0.123; P = 0.018; NRI = 0.101 95% CI -0.099-0.302; P = 0.321).

CONCLUSIONS

In elderly patients with PE, 6-month mortality can adequately be predicted by the PESI risk score alone.

Evolocumab for Early Reduction of LDL Cholesterol Levels in Patients With Acute Coronary Syndromes (EVOPACS)

BACKGROUND

Although guidelines recommend in-hospital initiation of high-intensity statin therapy in patients with acute coronary syndromes (ACS), low-density lipoprotein cholesterol (LDL-C) target levels are frequently not attained. Evolocumab, a rapidly acting, potent LDL-C-lowering drug, has not been studied in the acute phase of ACS.

OBJECTIVES

The purpose of this study was to assess the feasibility, safety, and LDL-C-lowering efficacy of evolocumab initiated during the in-hospital phase of ACS.

METHODS

The authors conducted an investigator-initiated, randomized, double-blind, placebo-controlled trial involving 308 patients hospitalized for ACS with elevated LDL-C levels (≥1.8 mmol/l on high-intensity statin for at least 4 weeks; ≥2.3 mmol/l on low- or moderate-intensity statin; or ≥3.2 mmol/l on no stable dose of statin). Patients were randomly assigned 1:1 to receive subcutaneous evolocumab 420 mg or matching placebo, administered in-hospital and after 4 weeks, on top of atorvastatin 40 mg. The primary endpoint was percentage change in calculated LDL-C from baseline to 8 weeks.

RESULTS

Most patients (78.2%) had not been on previous statin treatment. Mean LDL-C levels decreased from 3.61 to 0.79 mmol/l at week 8 in the evolocumab group, and from 3.42 to 2.06 mmol/l in the placebo group; the difference in mean percentage change from baseline was -40.7% (95% confidence interval: -45.2 to -36.2; p < 0.001). LDL-C levels <1.8 mmol/l were achieved at week 8 by 95.7% of patients in the evolocumab group versus 37.6% in the placebo group. Adverse events and centrally adjudicated cardiovascular events were similar in both groups.

CONCLUSIONS

In this first randomized trial assessing a PCSK9 antibody in the very high-risk setting of ACS, evolocumab added to high-intensity statin therapy was well tolerated and resulted in substantial reduction in LDL-C levels, rendering >95% of patients within currently recommended target levels. (EVOlocumab for Early Reduction of LDL-cholesterol Levels in Patients With Acute Coronary Syndromes [EVOPACS]; NCT03287609).

Trimethyllysine, a trimethylamine N-oxide precursor, provides near- and long-term prognostic value in patients presenting with acute coronary syndromes

AIMS

Trimethyllysine (TML) serves as a nutrient precursor of the gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) and is associated with incident cardiovascular (CV) events in stable subjects. We examined the relationship between plasma TML levels and incident CV events in patients presenting with acute coronary syndromes (ACS).

METHODS AND RESULTS

Plasma levels of TML were quantified in two independent cohorts using mass spectrometry, and its relationship with CV events was investigated. In a Cleveland Cohort (N = 530), comprised of patients presenting to the emergency department with chest pain and suspected ACS, TML was associated with major adverse cardiac events (MACE, myocardial infarction, stroke, need for revascularization, or all-cause mortality) over both 30 days [3rd tertile (T3), adjusted odds ratio (OR) 1.77, 95% confidence interval (CI) 1.04-3.01; P < 0.05] and 6 months (T3, adjusted OR 1.95, 95% CI 1.15-3.32; P < 0.05) of follow-up independent of traditional CV risk factors and indices of renal function. Elevated TML levels were also associated with incident long-term (7-year) all-cause mortality [T3, adjusted hazard ratio (HR) 2.52, 95% CI 1.50-4.24; P < 0.001], and MACE even amongst patients persistently negative for cardiac Troponin T at presentation (e.g. 30-day MACE, T3, adjusted OR 4.49, 95% CI 2.06-9.79; P < 0.001). Trimethyllysine in combination with TMAO showed additive significance for near- and long-term CV events, including patients with 'negative' high-sensitivity Troponin T levels. In a multicentre Swiss Cohort (N = 1683) comprised of ACS patients, similar associations between TML and incident 1-year adverse cardiac risks were observed (e.g. mortality, adjusted T3 HR 2.74, 95% CI 1.28-5.85; P < 0.05; and MACE, adjusted T3 HR 1.55, 95% CI 1.04-2.31; P < 0.05).

CONCLUSION

Plasma TML levels, alone and together with TMAO, are associated with both near- and long-term CV events in patients with chest pain and ACS.

Prognostic value of elevated lipoprotein(a) in patients with acute coronary syndromes

BACKGROUND

Minimal lipoprotein(a) [Lp(a)] target values are advocated for high-risk cardiovascular patients. We investigated the prognostic value of Lp(a) in the acute setting of patients with acute coronary syndromes (ACS).

MATERIALS AND METHODS

Plasma levels of Lp(a) were collected at time of angiography from 1711 patients hospitalized for ACS in a multicentre Swiss prospective cohort. Associations between elevated Lp(a) ≥30 mg/dL (cut-off corresponding to the 75th percentile of the assay) or Lp(a) tertiles at baseline, and major adverse cardiovascular events (MACE) at 1 year, defined as a composite of cardiac death, myocardial infarction or stroke, were assessed using hazard ratios (HR) and 95% confidence intervals (CI) adjusting for traditional cardiovascular risk factors (age, sex, smoking, diabetes, hypertension, low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C] and triglycerides.

RESULTS

Lp(a) levels range between 2.5 and 132 mg/dL with a median value of 6 mg/dL and a mean value of 14.2 mg/dL. A total of 276 patients (23.0%) had Lp(a) plasma levels ≥30 mg/dL. Patients with elevated Lp(a) were more likely to be of female gender and to have higher levels of total cholesterol, LDL-C, HDL-C and triglycerides. Higher Lp(a) was associated with failure to reach the LDL-C target <1.8 mmol/L at 1 year (HR 1.71, 95% CI 1.13-2.58, P = 0.01). No association was found between elevated Lp(a) and MACE at 1 year (HR 1.05, 95% CI 0.64-1.73), nor for Lp(a) tertiles (HR 0.82, 95% CI 0.52-1.28, P > 0.20) or standardized continuous variables (0.98, 95% CI 0.82-1.19 for each increase of standard deviation).

CONCLUSIONS

Our real-world data suggest high Lp(a) levels at time of angiography are not predictive for cardiovascular outcomes in patients otherwise medically well controlled, but might be useful to identify patients who would not be on LDL-C targets 1 year after ACS.

Prognostic value of total testosterone levels in patients with acute coronary syndromes

BACKGROUND

Endogenous testosterone levels decrease in men with aging. Controversies persist regarding the screening and treatment of low testosterone levels in patients with acute coronary syndromes (ACS).

METHODS AND RESULTS

Total serum testosterone levels were measured in 1054 men hospitalized for ACS that were part of a Swiss prospective cohort. Total testosterone levels were classified first in tertiles and using the cut-off of 300 ng/dL. Primary endpoint was all-cause mortality at one year. Cox regression models adjusting for the GRACE score (composite of age, heart rate systolic blood pressure, creatinine, cardiac arrest at admission, ST segment deviation, abnormal troponin enzyme and Killip classification), preexisting diabetes and inflammation (high-sensitivity C-reactive protein). A total of 430 men (40.8%) had total testosterone levels ≤300 ng/dL. Low total testosterone levels were correlated with lower high-density lipoprotein cholesterol and higher triglycerides, high-sensitivity C-reactive protein, high-sensitivity troponin T, N-terminal-pro B-type natriuretic peptide and glucose levels (all p < 0.01). Patients in the lowest testosterone tertile had a mortality rate at one-year of 5.4% compared with 2.9% in the highest tertile with an unadjusted hazard ratio of 1.92 (95% confidence interval 0.96-1.90, p = 0.095) and adjusted hazard ratio of 1.26 (95% confidence interval 0.57-2.78, p = 0.565). In an exploratory analysis, the highest mortality rate (10.3%) was observed in men aged >65 years old belonging to the lowest testosterone tertile.

CONCLUSION

In this large population of men with ACS, we found a prevalence of low total endogenous testosterone levels of almost 40%. However, low testosterone levels were not significantly associated with mortality after adjustment for high-risk confounders.

Association between income and control of cardiovascular risk factors after acute coronary syndromes: an observational study

BACKGROUND

The role of income in cardiovascular disease prevention after an acute coronary syndrome (ACS) remains unclear. We aimed to assess the association between income and control of cardiovascular risk factors one year after an ACS in a country with universal health insurance.

METHODS

Between 2013 and 2014, we studied 255 consecutive patients with ACS in an observational study in a university hospital in Switzerland in which self-reported household income was assessed. We classified patients into two categories based on the median income in Switzerland: higher than CHF 6000 (&euro; 5300) or less than or equal to CHF 6000 (&euro; 5300) per month. One year after discharge, patients were evaluated for the achievement of lipid and blood pressure targets, smoking cessation and drug adherence. Multivariate odds ratios (OR) were adjusted for age, sex, education, living status and working status.

RESULTS

Overall, 52.2% (n = 133) of patients with ACS were in the low-income category and 47.8% (n = 122) were in the high-income category. One year after discharge, high-income patients had higher rates of smoking cessation (64.2 vs 30.1%, multivariate-adjusted odds ratio (OR) 3.82, 95% confidence interval (CI) 1.58&ndash;9.24) and blood pressure target achievement (78.6 vs 60.2%, multivariate-adjusted OR 2.19, 95% CI 1.09&ndash;4.41) compared to those in the low-income category. There were no differences regarding adherence to drugs or lipid control between the two income groups.

CONCLUSION

A high household income was associated with a higher rate of smoking cessation and better control of blood pressure one year after ACS, independently of education, living status and working status.

A high Gas6 level in plasma predicts venous thromboembolism recurrence, major bleeding and mortality in the elderly: a prospective multicenter cohort study

Essentials Predictive ability of pro-hemostatic Gas6 for recurrent venous thromboembolism (VTE) is unknown. We measured Gas6 levels in 864 patients with VTE over 3 years. High Gas6 (> 157%) at diagnosis is associated with VTE recurrence, major bleeding and mortality. Gas6 plasma levels measured 12 months after the index VTE are discriminatory for VTE recurrence. SUMMARY: Background Growth arrest-specific gene 6 (Gas6) is a prohemostatic protein with an unknown predictive ability for recurrent venous thromboembolism (VTE). In the elderly, VTE results in higher mortality but does not have a higher rate of recurrence than in younger patients. Consequently, anticoagulation management in the elderly is challenging. Objective To prospectively investigate the performance of Gas6 in predicting VTE recurrence, major bleeding and mortality in the elderly. Methods Consecutive patients aged ≥ 65 years with acute VTE were followed for a period of 3 years. Primary outcomes were symptomatic VTE recurrence, major bleeding, and mortality. Plasma Gas6 was measured with ELISA. Results Gas6 levels were measured in 864 patients at the time of the index VTE (T1) and, in 70% of them, also 12 months later (T2). The Gas6 level at T1 was discriminatory for VTE recurrence (C-statistic, 0.56; 95% confidence interval [CI] 0.51-0.62), major bleeding (0.60, 95% CI 0.55-0.65) and mortality (0.69, 95% CI 0.65-0.73) up to 36 months. VTE recurrence up to 24 months after T2 was discriminated by the Gas6 level at T2 (0.62, 95% CI 0.54-0.71). High Gas6 levels (> 157%) and continuous Gas6 levels at T1 were associated with VTE recurrence up to 6 months and 12 months, respectively. Conclusions In elderly patients, a high Gas6 level is associated with higher risks of VTE recurrence, major bleeding, and death. These findings support further studies to assess the performance of Gas6 in adjusting the length of anticoagulation.