Inflammation in Metabolic Cardiomyopathy

Overlapping pandemics of lifestyle-related diseases pose a substantial threat to cardiovascular health. Apart from coronary artery disease, metabolic disturbances linked to obesity, insulin resistance and diabetes directly compromise myocardial structure and function through independent and shared mechanisms heavily involving inflammatory signals. Accumulating evidence indicates that metabolic dysregulation causes systemic inflammation, which in turn aggravates cardiovascular disease. Indeed, elevated systemic levels of pro-inflammatory cytokines and metabolic substrates induce an inflammatory state in different cardiac cells and lead to subcellular alterations thereby promoting maladaptive myocardial remodeling. At the cellular level, inflammation-induced oxidative stress, mitochondrial dysfunction, impaired calcium handling, and lipotoxicity contribute to cardiomyocyte hypertrophy and dysfunction, extracellular matrix accumulation and microvascular disease. In cardiometabolic patients, myocardial inflammation is maintained by innate immune cell activation mediated by pattern recognition receptors such as Toll-like receptor 4 (TLR4) and downstream activation of the NLRP3 inflammasome and NF-κB-dependent pathways. Chronic low-grade inflammation progressively alters metabolic processes in the heart, leading to a metabolic cardiomyopathy (MC) phenotype and eventually to heart failure with preserved ejection fraction (HFpEF). In accordance with preclinical data, observational studies consistently showed increased inflammatory markers and cardiometabolic features in patients with HFpEF. Future treatment approaches of MC may target inflammatory mediators as they are closely intertwined with cardiac nutrient metabolism. Here, we review current evidence on inflammatory processes involved in the development of MC and provide an overview of nutrient and cytokine-driven pro-inflammatory effects stratified by cell type

Growth differentiation factor-15 and prediction of cancer-associated thrombosis and mortality: a prospective cohort study

Background Patients with cancer are at increased risk of venous thromboembolism (VTE) and arterial thromboembolic/thrombotic events (ATEs). Growth differentiation factor-15 (GDF-15) improves cardiovascular risk assessment, but its predictive utility in patients with cancer remains undefined. Objectives To investigate the association of GDF-15 with the risks of VTE, ATE, and mortality in patients with cancer and its predictive utility alongside established models. Methods The Vienna Cancer and Thrombosis Study (CATS)—a prospective, observational cohort study of patients with newly diagnosed or recurrent cancer—which was followed for 2 years, served as the study framework. Serum GDF-15 levels at study inclusion were measured, and any association with VTE, ATE, and death was determined using competing risk (VTE/ATE) or Cox regression (death) modeling. The added value of GDF-15 to established VTE risk prediction models was assessed using the Khorana and Vienna CATScore. Results Among 1531 included patients with cancer (median age, 62 years; 53% men), median GDF-15 levels were 1004 ng/L (IQR, 654-1750). Increasing levels of GDF-15 were associated with the increased risks of VTE, ATE, and all-cause death ([subdistribution] hazard ratio per doubling, 1.16 [95% CI, 1.03-1.32], 1.30 [95% CI, 1.11-1.53], and 1.57 [95% CI, 1.46-1.69], respectively). After adjustment for clinically relevant covariates, the association only prevailed for all-cause death (hazard ratio, 1.21; 95% CI, 1.10-1.33) and GDF-15 did not improve the performance of the Khorana or Vienna CATScore. Conclusion GDF-15 is strongly associated with survival in patients with cancer, independent of the established risk factors. While an association with ATE and VTE was identified in univariable analysis, GDF-15 was not independently associated with these outcomes and failed to improve established VTE prediction models

Chronic SIRT1 supplementation in diabetic mice improves endothelial function by suppressing oxidative stress

Aims Enhancing SIRT1 activity exerts beneficial cardiovascular effects. In diabetes, plasma SIRT1 levels are reduced. We aimed to investigate the therapeutic potential of chronic recombinant murine SIRT1 (rmSIRT1) supplementation to alleviate endothelial and vascular dysfunction in diabetic mice (db/db). Methods and results Left internal mammary arteries obtained from patients undergoing coronary artery bypass grafting with or without a diagnosis of diabetes were assayed for SIRT1 protein levels. Twelve-week-old male db/db mice and db/+ controls were treated with vehicle or rmSIRT1 intraperitoneally for 4 weeks, after which carotid artery pulse wave velocity (PWV) and energy expenditure/activity were assessed by ultrasound and metabolic cages, respectively. Aorta, carotid, and mesenteric arteries were isolated to determine endothelial and vascular function using the myograph system. Arteries obtained from diabetic patients had significantly lower levels of SIRT1 relative to non-diabetics. In line, aortic SIRT1 levels were reduced in db/db mice compared to db/+ mice, while rmSIRT1 supplementation restored SIRT1 levels. Mice receiving rmSIRT1 supplementation displayed increased physical activity and improved vascular compliance as reflected by reduced PWV and attenuated collagen deposition. Aorta of rmSIRT1-treated mice exhibited increased endothelial nitric oxide (eNOS) activity, while endothelium-dependent contractions of their carotid arteries were significantly decreased, with mesenteric resistance arteries showing preserved hyperpolarization. Ex vivo incubation with reactive oxygen species (ROS) scavenger Tiron and NADPH oxidase inhibitor apocynin revealed that rmSIRT1 leads to preserved vascular function by suppressing NADPH oxidase (NOX)-related ROS synthesis. Chronic rmSIRT1 treatment resulted in reduced expression of both NOX1 and NOX4, in line with a reduction in aortic protein carbonylation and plasma nitrotyrosine levels. Conclusions In diabetic conditions, arterial SIRT1 levels are significantly reduced. Chronic rmSIRT1 supplementation improves endothelial function and vascular compliance by enhancing eNOS activity and suppressing NOX-related oxidative stress. Thus, SIRT1 supplementation may represent novel therapeutic strategy to prevent diabetic vascular disease

History of peripheral artery disease and cardiovascular risk of real-world patients with acute coronary syndrome: Role of inflammation and comorbidities

BACKGROUND Patients with acute coronary syndromes (ACS) remain at risk of cardiovascular disease (CVD) recurrences. Peripheral artery disease (PAD) may identify a very high risk (VHR) group who may derive greater benefit from intensified secondary prevention. METHODS Among ACS-patients enrolled in the prospective multi-center Special Program University Medicine (SPUM), we assessed the impact of PAD on major cardiovascular events (MACE: composite of myocardial infarction, stroke and all-cause death) and major bleeding. Multivariate analysis tested the relation of each significant variable with MACE, as well as biomarkers of inflammation and novel markers of atherogenesis. RESULTS Out of 4787 ACS patients, 6.0% (n = 285) had PAD. PAD-patients were older (p < 0.001), with established CVD and signs of increased persistent inflammation (hs-CRP; 23.6 ± 46.5 vs 10.4 ± 27.2 mg/l, p < 0.001 and sFlt-1; 1399.5 ± 1501.3 vs 1047.2 ± 1378.6 ng/l, p = 0.018). In-hospital-death (3.2% vs 1.4%, p = 0.022) and -MACE (5.6% vs 3.0%, p = 0.017) were higher in PAD-patients. MACE at 1 year (18.6% vs 7.9%,p < 0.001) remained increased even after adjustment for confounders (Adj. HR 1.53, 95% CI: 1.14-2.08, p = 0.005). Major bleeding did not differ between groups (Adj. HR 1.18; 95% CI 0.71-1.97, p = 0.512). Although PAD predicted MACE, PAD-patients were prescribed less frequently for secondary prevention at discharge. CONCLUSIONS In this real-world ACS patient cohort, concomitant PAD is a marker of VHR and is associated with increased and persistent inflammation, higher risk for MACE without an increased risk of major bleeding. Therefore, a history of PAD may be useful to identify those ACS patients at VHR who require more aggressive secondary prevention

History of peripheral artery disease and cardiovascular risk of real-word patients with acute coronary syndrome: Role of inflammation and comorbidities.

BACKGROUND Patients with acute coronary syndromes (ACS) remain at risk of cardiovascular disease (CVD) recurrences. Peripheral artery disease (PAD) may identify a very high risk (VHR) group who may derive greater benefit from intensified secondary prevention. METHODS Among ACS-patients enrolled in the prospective multi-center Special Program University Medicine (SPUM), we assessed the impact of PAD on major cardiovascular events (MACE: composite of myocardial infarction, stroke and all-cause death) and major bleeding. Multivariate analysis tested the relation of each significant variable with MACE, as well as biomarkers of inflammation and novel markers of atherogenesis. RESULTS Out of 4787 ACS patients, 6.0% (n = 285) had PAD. PAD-patients were older (p < 0.001), with established CVD and signs of increased persistent inflammation (hs-CRP; 23.6 ± 46.5 vs 10.4 ± 27.2 mg/l, p < 0.001 and sFlt-1; 1399.5 ± 1501.3 vs 1047.2 ± 1378.6 ng/l, p = 0.018). In-hospital-death (3.2% vs 1.4%, p = 0.022) and -MACE (5.6% vs 3.0%, p = 0.017) were higher in PAD-patients. MACE at 1 year (18.6% vs 7.9%,p < 0.001) remained increased even after adjustment for confounders (Adj. HR 1.53, 95% CI: 1.14-2.08, p = 0.005). Major bleeding did not differ between groups (Adj. HR 1.18; 95% CI 0.71-1.97, p = 0.512). Although PAD predicted MACE, PAD-patients were prescribed less frequently for secondary prevention at discharge. CONCLUSIONS In this real-world ACS patient cohort, concomitant PAD is a marker of VHR and is associated with increased and persistent inflammation, higher risk for MACE without an increased risk of major bleeding. Therefore, a history of PAD may be useful to identify those ACS patients at VHR who require more aggressive secondary prevention

Loss of autophagy protein ATG5 impairs cardiac capacity in mice and humans through diminishing mitochondrial abundance and disrupting Ca2+Ca^{\text{2+}} cycling

Aims Autophagy protects against the development of cardiac hypertrophy and failure. While aberrant Ca2+ handling promotes myocardial remodelling and contributes to contractile dysfunction, the role of autophagy in maintaining Ca2+ homeostasis remains elusive. Here, we examined whether Atg5 deficiency-mediated autophagy promotes early changes in subcellular Ca2+ handling in ventricular cardiomyocytes, and whether those alterations associate with compromised cardiac reserve capacity, which commonly precedes the onset of heart failure. Methods and results RT–qPCR and immunoblotting demonstrated reduced Atg5 gene and protein expression and decreased abundancy of autophagy markers in hypertrophied and failing human hearts. The function of ATG5 was examined using cardiomyocyte-specific Atg5-knockout mice (Atg5−/−). Before manifesting cardiac dysfunction, Atg5−/− mice showed compromised cardiac reserve in response to β-adrenergic stimulation. Consequently, effort intolerance and maximal oxygen consumption were reduced during treadmill-based exercise tolerance testing. Mechanistically, cellular imaging revealed that Atg5 deprivation did not alter spatial and functional organization of intracellular Ca2+ stores or affect Ca2+ cycling in response to slow pacing or upon acute isoprenaline administration. However, high-frequency stimulation exposed stunted amplitude of Ca2+ transients, augmented nucleoplasmic Ca2+ load, and increased CaMKII activity, especially in the nuclear region of hypertrophied Atg5−/− cardiomyocytes. These changes in Ca2+ cycling were recapitulated in hypertrophied human cardiomyocytes. Finally, ultrastructural analysis revealed accumulation of mitochondria with reduced volume and size distribution, meanwhile functional measurements showed impaired redox balance in Atg5−/− cardiomyocytes, implying energetic unsustainability due to overcompensation of single mitochondria, particularly under increased workload. Conclusion Loss of cardiac Atg5-dependent autophagy reduces mitochondrial abundance and causes subtle alterations in subcellular Ca2+ cycling upon increased workload in mice. Autophagy-related impairment of Ca2+ handling is progressively worsened by β-adrenergic signalling in ventricular cardiomyocytes, thereby leading to energetic exhaustion and compromised cardiac reserve

Occlusion of the infarct-related coronary artery presenting as acute coronary syndrome with and without ST-elevation: impact of inflammation and outcomes in a real-world prospective cohort

Background Patients with ST-segment elevation typically feature total coronary occlusion (TCO) of the infarct-related artery (IRA) on angiography, which may result in worse outcomes. Yet, relying solely on electrocardiogram (ECG) findings may be misleading and those presenting with non-ST-segment elevation acute coronary syndromes (NSTE-ACSs) may have TCO as well. Herein, we aimed to delineate clinical characteristics and outcomes of patients with ACS stratified by IRA location. Methods A total of 4787 ACS patients were prospectively recruited between 2009 and 2017 in SPUM-ACS (ClinicalTrials.gov Identifier: NCT01000701). The primary endpoint was major adverse cardiovascular events (MACEs), a composite of all-cause death, non-fatal myocardial infarction and non-fatal stroke at 1 year. Multivariable-adjusted survival models were fitted using backward selection. Results A total of 4412 ACS patients were included in this analysis, 56.0% (n = 2469) ST-elevation myocardial infarction (STEMI) and 44.0% (n = 1943) NSTE-ACS. The IRA was the right coronary artery (RCA) in 33.9% (n = 1494), the left-anterior descending coronary artery (LAD) in 45.6% (n = 2013), and the left circumflex (LCx) in 20.5% (n = 905) patients. In STEMI patients, TCO (defined as TIMI 0 flow at angiography) was observed in 55% of cases with LAD, in 63% with RCA, and in 55% with LCx. In those presenting with NSTE-ACS, TCO was more frequent in those with LCx and RCA as compared to the LAD (27 and 24%, respectively, vs. 9%, P &lt; 0.001). Among patients with NSTE-ACS, occlusion of the LCx was associated with an increased risk of MACE during 1 year after the index ACS (fully adjusted hazard ratio 1.68, 95% confidence interval 1.10–2.59, P = 0.02; reference: RCA and LAD). Features of patients with NSTE-ACS associated with TCO of the IRA included elevated lymphocyte and neutrophil counts, higher levels of high-sensitivity C reactive protein (hs-CRP) and high-sensitivity cardiac troponin T, lower eGFR, and notably a negative history of MI. Conclusion In NSTE-ACS, both LCx and RCA involvement was associated with TCO at angiography despite the absence of ST-segment elevation. Involvement of the LCx, but not the LAD or RCA, as the IRA represented an independent predictor of MACE during 1-year follow-up. Hs-CRP, lymphocyte, and neutrophil counts were independent predictors of total IRA occlusion, suggesting a possible role of systemic inflammation in the detection of TCO irrespective of ECG presentation

Sex-specific evaluation and redevelopment of the GRACE score in non-ST-segment elevation acute coronary syndromes in populations from the UK and Switzerland: a multinational analysis with external cohort validation.

BACKGROUND The Global Registry of Acute Coronary Events (GRACE) 2.0 score was developed and validated in predominantly male patient populations. We aimed to assess its sex-specific performance in non-ST-segment elevation acute coronary syndromes (NSTE-ACS) and to develop an improved score (GRACE 3.0) that accounts for sex differences in disease characteristics. METHODS We evaluated the GRACE 2.0 score in 420 781 consecutive patients with NSTE-ACS in contemporary nationwide cohorts from the UK and Switzerland. Machine learning models to predict in-hospital mortality were informed by the GRACE variables and developed in sex-disaggregated data from 386 591 patients from England, Wales, and Northern Ireland (split into a training cohort of 309 083 [80·0%] patients and a validation cohort of 77 508 [20·0%] patients). External validation of the GRACE 3.0 score was done in 20 727 patients from Switzerland. FINDINGS Between Jan 1, 2005, and Aug 27, 2020, 400 054 patients with NSTE-ACS in the UK and 20 727 patients with NSTE-ACS in Switzerland were included in the study. Discrimination of in-hospital death by the GRACE 2.0 score was good in male patients (area under the receiver operating characteristic curve [AUC] 0·86, 95% CI 0·86-0·86) and notably lower in female patients (0·82, 95% CI 0·81-0·82; p<0·0001). The GRACE 2.0 score underestimated in-hospital mortality risk in female patients, favouring their incorrect stratification to the low-to-intermediate risk group, for which the score does not indicate early invasive treatment. Accounting for sex differences, GRACE 3.0 showed superior discrimination and good calibration with an AUC of 0·91 (95% CI 0·89-0·92) in male patients and 0·87 (95% CI 0·84-0·89) in female patients in an external cohort validation. GRACE 3·0 led to a clinically relevant reclassification of female patients to the high-risk group. INTERPRETATION The GRACE 2.0 score has limited discriminatory performance and underestimates in-hospital mortality in female patients with NSTE-ACS. The GRACE 3.0 score performs better in men and women and reduces sex inequalities in risk stratification. FUNDING Swiss National Science Foundation, Swiss Heart Foundation, Lindenhof Foundation, Foundation for Cardiovascular Research, and Theodor-Ida-Herzog-Egli Foundation

Nogo-A is secreted in extracellular vesicles, occurs in blood and can influence vascular permeability

Nogo-A is a transmembrane protein with multiple functions in the central nervous system (CNS), including restriction of neurite growth and synaptic plasticity. Thus far, Nogo-A has been predominantly considered a cell contact-dependent ligand signaling via cell surface receptors. Here, we show that Nogo-A can be secreted by cultured cells of neuronal and glial origin in association with extracellular vesicles (EVs). Neuron- and oligodendrocyte-derived Nogo-A containing EVs inhibited fibroblast spreading, and this effect was partially reversed by Nogo-A receptor S1PR2 blockage. EVs purified from HEK cells only inhibited fibroblast spreading upon Nogo-A over-expression. Nogo-A-containing EVs were found in vivo in the blood of healthy mice and rats, as well as in human plasma. Blood Nogo-A concentrations were elevated after acute stroke lesions in mice and rats. Nogo-A active peptides decreased barrier integrity in an in vitro blood-brain barrier model. Stroked mice showed increased dye permeability in peripheral organs when tested 2 weeks after injury. In the Miles assay, an in vivo test to assess leakage of the skin vasculature, a Nogo-A active peptide increased dye permeability. These findings suggest that blood borne, possibly EV-associated Nogo-A could exert long-range regulatory actions on vascular permeability