Interleukin-1 receptor accessory protein blockade limits the development of atherosclerosis and reduces plaque inflammation.

AIMS: The interleukin-1 receptor accessory protein (IL1RAP) is a co-receptor required for signalling through the IL-1, IL-33, and IL-36 receptors. Using a novel anti-IL1RAP-blocking antibody, we investigated the role of IL1RAP in atherosclerosis. METHODS AND RESULTS: Single-cell RNA sequencing data from human atherosclerotic plaques revealed the expression of IL1RAP and several IL1RAP-related cytokines and receptors, including IL1B and IL33. Histological analysis showed the presence of IL1RAP in both the plaque and adventitia, and flow cytometry of murine atherosclerotic aortas revealed IL1RAP expression on plaque leucocytes, including neutrophils and macrophages. High-cholesterol diet fed apolipoprotein E-deficient (Apoe-/-) mice were treated with a novel non-depleting IL1RAP-blocking antibody or isotype control for the last 6 weeks of diet. IL1RAP blockade in mice resulted in a 20% reduction in subvalvular plaque size and limited the accumulation of neutrophils and monocytes/macrophages in plaques and of T cells in adventitia, compared with control mice. Indicative of reduced plaque inflammation, the expression of several genes related to leucocyte recruitment, including Cxcl1 and Cxcl2, was reduced in brachiocephalic arteries of anti-IL1RAP-treated mice, and the expression of these chemokines in human plaques was mainly restricted to CD68+ myeloid cells. Furthermore, in vitro studies demonstrated that IL-1, IL-33, and IL-36 induced CXCL1 release from both macrophages and fibroblasts, which could be mitigated by IL1RAP blockade. CONCLUSION: Limiting IL1RAP-dependent cytokine signalling pathways in atherosclerotic mice reduces plaque burden and plaque inflammation, potentially by limiting plaque chemokine production.

Elevated soluble LOX-1 predicts risk of first-time myocardial infarction.

BACKGROUND: There is an unmet clinical need for novel therapies addressing the residual risk in patients receiving guideline preventive therapy for coronary heart disease. Experimental studies have identified a pro-atherogenic role of the oxidized LDL receptor LOX-1. We investigated the association between circulating soluble LOX-1 (sLOX-1) and the risk for development of myocardial infarction. METHODS: The study subjects (n = 4658) were part of the Malmö Diet and Cancer study. The baseline investigation was carried out 1991-1994 and the incidence of cardiovascular events monitored through national registers during a of 19.5 ± 4.9 years follow-up. sLOX-1 and other biomarkers were analyzed by proximity extension assay and ELISA in baseline plasma. RESULTS: Subjects in the highest tertile of sLOX-1 had an increased risk of myocardial infarction (hazard ratio (95% CI) 1.76 (1.40-2.21) as compared with those in the lowest tertile. The presence of cardiovascular risk factors was related to elevated sLOX-1, but the association between sLOX-1 and risk of myocardial infarction remained significant when adjusting for risk factors. CONCLUSIONS: In this prospective population study we found an association between elevated sLOX-1, the presence of carotid disease and the risk for first-time myocardial infarction. Taken together with previous experimental findings of a pro-atherogenic role of LOX-1, this observation supports LOX-1 inhibition as a possible target for prevention of myocardial infarction.

Activation of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) represents a possible target for treatment of the residual inflammatory risk in cardiovascular patients on guideline therapy.Having high levels of soluble LOX-1, a marker of cellular LOX-1 activation, is associated with an increased risk for development of myocardial infarction and heart failure.sLOX-1 levels correlated with major cardiovascular risk factors and biomarkers reflecting LDL oxidation.

Invariant natural killer T cells and incidence of first-time coronary events: a nested case-control study.

Aims: Invariant natural killer T (iNKT) cells, a T cell subset that is CD1d-restricted and expresses a semi-invariant T cell receptor, have been proposed to contribute to dyslipidaemia-driven cardiovascular disease due to their ability to specifically recognize lipid antigens. Studies in mice have attributed pro-atherogenic properties to iNKT cells, but studies in humans investigating associations of iNKT cells with incident coronary events (CE) are lacking. Methods and results: Here, we used flow cytometry to enumerate circulating iNKT cells (CD3+ CD1d-PBS57-Tetramer+) in a case-control cohort nested within the prospective population-based Malmö Diet and Cancer Study (n = 416) to explore associations with incident first-time CE during a median follow-up of 14 years. We found a significant inverse association between CD4- and CD8- double negative (DN) iNKT cells and incident CE, with an odds ratio of 0.62 [95% confidence interval (CI) 0.38-0.99; P = 0.046] comparing the highest vs. the lowest tertile of DN iNKT cells. The association remained significant after adjustment for cardiovascular risk factors with an odds ratio of 0.57 (95% CI 0.33-0.99; P = 0.046). In contrast, total iNKT cells were not significantly associated with incident CE after adjustment, with an odds ratio of 0.74 (95% CI 0.43-1.27; P = 0.276). Conclusion: Our findings indicate that animal studies suggesting an atherosclerosis-promoting role for iNKT cells may not translate to human cardiovascular disease as our data show an association between high circulating numbers of DN iNKT cells and decreased risk of incident CE.

Therapeutic S100A8/A9 blockade inhibits myocardial and systemic inflammation and mitigates sepsis-induced myocardial dysfunction.

BACKGROUND AND AIMS: The triggering factors of sepsis-induced myocardial dysfunction (SIMD) are poorly understood and are not addressed by current treatments. S100A8/A9 is a pro-inflammatory alarmin abundantly secreted by activated neutrophils during infection and inflammation. We investigated the efficacy of S100A8/A9 blockade as a potential new treatment in SIMD. METHODS: The relationship between plasma S100A8/A9 and cardiac dysfunction was assessed in a cohort of 62 patients with severe sepsis admitted to the intensive care unit of Linköping University Hospital, Sweden. We used S100A8/A9 blockade with the small-molecule inhibitor ABR-238901 and S100A9-/- mice for therapeutic and mechanistic studies on endotoxemia-induced cardiac dysfunction in mice. RESULTS: In sepsis patients, elevated plasma S100A8/A9 was associated with left-ventricular (LV) systolic dysfunction and increased SOFA score. In wild-type mice, 5 mg/kg of bacterial lipopolysaccharide (LPS) induced rapid plasma S100A8/A9 increase and acute LV dysfunction. Two ABR-238901 doses (30 mg/kg) administered intraperitoneally with a 6 h interval, starting directly after LPS or at a later time-point when LV dysfunction is fully established, efficiently prevented and reversed the phenotype, respectively. In contrast, dexamethasone did not improve cardiac function compared to PBS-treated endotoxemic controls. S100A8/A9 inhibition potently reduced systemic levels of inflammatory mediators, prevented upregulation of inflammatory genes and restored mitochondrial function in the myocardium. The S100A9-/- mice were protected against LPS-induced LV dysfunction to an extent comparable with pharmacologic S100A8/A9 blockade. The ABR-238901 treatment did not induce an additional improvement of LV function in the S100A9-/- mice, confirming target specificity. CONCLUSION: Elevated S100A8/A9 is associated with the development of LV dysfunction in severe sepsis patients and in a mouse model of endotoxemia. Pharmacological blockade of S100A8/A9 with ABR-238901 has potent anti-inflammatory effects, mitigates myocardial dysfunction and might represent a novel therapeutic strategy for patients with severe sepsis.

Vascular smooth muscle-specific YAP/TAZ deletion triggers aneurysm development in mouse aorta.

Inadequate adaption to mechanical forces, including blood pressure, contributes to development of arterial aneurysms. Recent studies have pointed to a mechanoprotective role of YAP and TAZ in vascular smooth muscle cells (SMCs). Here, we identified reduced expression of YAP1 in human aortic aneurysms. Vascular SMC-specific knockouts (KOs) of YAP/TAZ were thus generated using the integrin α8-Cre (Itga8-Cre) mouse model (i8-YT-KO). i8-YT-KO mice spontaneously developed aneurysms in the abdominal aorta within 2 weeks of KO induction and in smaller arteries at later times. The vascular specificity of Itga8-Cre circumvented gastrointestinal effects. Aortic aneurysms were characterized by elastin disarray, SMC apoptosis, and accumulation of proteoglycans and immune cell populations. RNA sequencing, proteomics, and myography demonstrated decreased contractile differentiation of SMCs and impaired vascular contractility. This associated with partial loss of myocardin expression, reduced blood pressure, and edema. Mediators in the inflammatory cGAS/STING pathway were increased. A sizeable increase in SOX9, along with several direct target genes, including aggrecan (Acan), contributed to proteoglycan accumulation. This was the earliest detectable change, occurring 3 days after KO induction and before the proinflammatory transition. In conclusion, Itga8-Cre deletion of YAP and TAZ represents a rapid and spontaneous aneurysm model that recapitulates features of human abdominal aortic aneurysms.

S100A8∕A9 is a valuable biomarker and treatment target to detect and modulate neutrophil involvement in myocardial infarction.

Myocardial infarction (MI) leads to irreversible ischemic damage of the heart muscle and is the leading cause of heart failure. The ischemic cardiac injury triggers a potent local and systemic immune response. In the acute phase post-MI, neutrophils infiltrate the myocardium in large numbers and induce further cardiomyocyte death, expanding the infarcted area. The alarmin S100A8∕A9 is a proinflammatory mediator primarily produced by myeloid cells, with an emerging role in MI. We previously demonstrated that short-term inhibition of S100A8∕A9 during the inflammatory phase of the immune response to MI improves long-term cardiac function. In the present study, we investigated the effects of S100A8∕A9 blockade on myocardial inflammation and post-ischemic myocardial injury in a mouse model of coronary artery ligation. Immunohistochemical (IHC) staining revealed that the presence of S100A9 is strongly correlated with neutrophil infiltration in the myocardium on days 1 and 3 post-MI. A 3-day treatment with the S100A8∕A9 blocker ABR-238901 starting immediately after MI decreased the number of neutrophils and S100A9 presence in the myocardium and had a positive impact on cardiac damage, reducing infarction size. These findings promote S100A9 as an IHC biomarker of neutrophil infiltration and a promising immunomodulatory target to regulate neutrophil recruitment, reduce ischemic injury and promote long-term beneficial cardiac recovery after MI.

Organizational and patient-level predictors for attaining key risk factor targets in cardiac rehabilitation after myocardial infarction: The Perfect-CR study.

BACKGROUND: Benefits of cardiac rehabilitation (CR) programme components on attaining risk factor targets post-myocardial infarction (MI) and their predictive strength relative to patient characteristics remain unclear. We aimed to identify organizational and patient-level predictors of risk factor target attainment at one-year post-MI. METHODS: In this observational study data on CR organization at 78 Swedish CR centres was collected and merged with patient-level registry data (n = 7549). Orthogonal partial least squares discriminant analysis identified predictors (Variables of Importance for the Projection (VIP) values >0.8) of attaining low-density lipoprotein-cholesterol (LDL-C) <1.8 mmol/L, blood pressure (BP) <140/90 mmHg and smoking abstinence. RESULTS: The strongest predictors (VIP [95% CI]) for attaining LDL-C and BP targets were offering psychosocial management (2.14 [1.78-2.50]; 2.45 [1.91-2.99]), having a psychologist in the CR team (1.62 [1.36-1.87]; 2.05 [1.67-2.44]), extended opening hours (2.13 [2.00-2.27]; 1.50 [0.91-2.10]), adequate facilities (1.54 [0.91-2.18]; 1.89 [1.38-2.40]), and having a medical director (1.70 [0.91-2.48]; 1.46 [1.04-1.88]). The strongest patient-level predictors of attaining LDL-C and/or BP targets were low baseline LDL-C (3.95 [3.39-4.51]) and having no history of hypertension (2.93 [2.60-3.26]), respectively, followed by exercise-based CR participation (1.38 [0.66-2.10]; 1.46 [1.14-1.78]). For smoking abstinence, the strongest organizational predictor was varenicline being prescribed by CR physicians (1.88 [0.95-2.80]) and patient-level predictors were participation in exercise-based CR (2.47 [2.07-2.88]) and group education (1.92 [1.43-2-42]), and no cardiovascular disease history (2.13 [1.78-2.48]). CONCLUSIONS: We identified multiple CR organizational and patient-level predictors of attaining risk factor targets post-MI. These results may influence the future design of comprehensive CR programmes.

S100A9 induces reactive oxygen species-dependent formation of neutrophil extracellular traps in abdominal sepsis.

Recent evidence suggests that targeting S100A9 reduces pathological inflammation in abdominal sepsis. Herein, we investigated the role of S100A9 in neutrophil extracellular trap (NET) formation in septic lung damage. NETs were detected by electron microscopy in the lung and by confocal microscopy in vitro. Stimulation of isolated mouse bone marrow-derived neutrophils with S100A9 triggered formation of NETs. Blocking TLR4 and RAGE reduced S100A9-induced generation of NETs and DNA-histone complexes. Moreover, S100A9 challenge increased generation of reactive oxygen species (ROS) in bone marrow neutrophils. Co-incubation with the NADPH oxidase inhibitor not only decreased ROS formation but also attenuated induction of DNA-histone complexes in S100A9-stimulated neutrophils. Abdominal sepsis was induced by cecal ligation and puncture (CLP) in male C57BL/6 mice. Administration of the S100A9 inhibitor ABR-238901 decreased CLP-induced formation of NETs in lungs and DNA-histone complexes in plasma. In addition, transmission electron microscopy revealed that S100A9 was abundantly expressed on NETs in the lungs in CLP mice. By use of intravital microscopy, we found that local injection of NETs increased leukocyte adhesion and migration in the mouse cremaster muscle microvasculature. Notably, treatment with ABR-238901 attenuated NET-induced leukocyte adhesion and extravasation in the cremaster muscle, suggesting that NET-associated S100A9 promotes leukocyte recruitment in vivo. Taken together, these novel findings suggest that S100A9 triggers ROS-dependent formation of NETs via TLR4 and RAGE signaling in neutrophils. Moreover, S100A9 regulates both formation of NETs and NET-induced leukocyte recruitment in vivo. Thus, targeting S100A9 might be useful to ameliorate lung damage in abdominal sepsis.

Short-Term Blockade of Pro-Inflammatory Alarmin S100A9 Favorably Modulates Left Ventricle Proteome and Related Signaling Pathways Involved in Post-Myocardial Infarction Recovery.

Prognosis after myocardial infarction (MI) varies greatly depending on the extent of damaged area and the management of biological processes during recovery. Reportedly, the inhibition of the pro-inflammatory S100A9 reduces myocardial damage after MI. We hypothesize that a S100A9 blockade induces changes of major signaling pathways implicated in post-MI healing. Mass spectrometry-based proteomics and gene analyses of infarcted mice left ventricle were performed. The S100A9 blocker (ABR-23890) was given for 3 days after coronary ligation. At 3 and 7 days post-MI, ventricle samples were analyzed versus control and Sham-operated mice. Blockade of S100A9 modulated the expressed proteins involved in five biological processes: leukocyte cell-cell adhesion, regulation of the muscle cell apoptotic process, regulation of the intrinsic apoptotic signaling pathway, sarcomere organization and cardiac muscle hypertrophy. The blocker induced regulation of 36 proteins interacting with or targeted by the cellular tumor antigen p53, prevented myocardial compensatory hypertrophy, and reduced cardiac markers of post-ischemic stress. The blockade effect was prominent at day 7 post-MI when the quantitative features of the ventricle proteome were closer to controls. Blockade of S100A9 restores key biological processes altered post-MI. These processes could be valuable new pharmacological targets for the treatment of ischemic heart. Mass spectrometry data are available via ProteomeXchange with identifier PXD033683.

Effect of a Lifestyle-Focused Web-Based Application on Risk Factor Management in Patients Who Have Had a Myocardial Infarction: Randomized Controlled Trial.

BACKGROUND: Cardiac rehabilitation is central in reducing mortality and morbidity after myocardial infarction. However, the fulfillment of guideline-recommended cardiac rehabilitation targets is unsatisfactory. eHealth offers new possibilities to improve clinical care. OBJECTIVE: This study aims to assess the effect of a web-based application designed to support adherence to lifestyle advice and self-control of risk factors (intervention) in addition to center-based cardiac rehabilitation, compared with cardiac rehabilitation only (usual care). METHODS: All 150 patients participated in cardiac rehabilitation. Patients randomized to the intervention group (n=101) received access to the application for 25 weeks where information about lifestyle (eg, diet and physical activity), risk factors (eg, weight and blood pressure [BP]), and symptoms could be registered. The software provided feedback and lifestyle advice. The primary outcome was a change in submaximal exercise capacity (Watts [W]) between follow-up visits. Secondary outcomes included changes in modifiable risk factors between baseline and follow-up visits and uptake and adherence to the application. Regression analysis was used, adjusting for relevant baseline variables. RESULTS: There was a nonsignificant trend toward a larger change in exercise capacity in the intervention group (n=66) compared with the usual care group (n=40; +14.4, SD 19.0 W, vs +10.3, SD 16.1 W; P=.22). Patients in the intervention group achieved significantly larger BP reduction compared with usual care patients at 2 weeks (systolic -27.7 vs -16.4 mm Hg; P=.006) and at 6 to 10 weeks (systolic -25.3 vs -16.4 mm Hg; P=.02, and diastolic -13.4 vs -9.1 mm Hg; P=.05). A healthy diet index score improved significantly more between baseline and the 2-week follow-up in the intervention group (+2.3 vs +1.4 points; P=.05), mostly owing to an increase in the consumption of fish and fruit. At 6 to 10 weeks, 64% (14/22) versus 46% (5/11) of smokers in the intervention versus usual care groups had quit smoking, and at 12 to 14 months, the respective percentages were 55% (12/22) versus 36% (4/11). However, the number of smokers in the study was low (33/149, 21.9%), and the differences were nonsignificant. Attendance in cardiac rehabilitation was high, with 96% (96/100) of patients in the intervention group and 98% (48/49) of patients receiving usual care only attending 12- to 14-month follow-up. Uptake (logging data in the application at least once) was 86.1% (87/101). Adherence (logging data at least twice weekly) was 91% (79/87) in week 1 and 56% (49/87) in week 25. CONCLUSIONS: Complementing cardiac rehabilitation with a web-based application improved BP and dietary habits during the first months after myocardial infarction. A nonsignificant tendency toward better exercise capacity and higher smoking cessation rates was observed. Although the study group was small, these positive trends support further development of eHealth in cardiac rehabilitation. TRIAL REGISTRATION: ClinicalTrials.gov NCT03260582; https://clinicaltrials.gov/ct2/show/NCT03260582. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1186/s13063-018-3118-1.

Safety of early hospital discharge following admission with ST-elevation myocardial infarction treated with percutaneous coronary intervention: a nationwide cohort study.

BACKGROUND: The Second Primary Angioplasty in Myocardial Infarction (PAMI-II) risk score is recommended by guidelines to identify low-risk patients with ST-elevation myocardial infarction (STEMI) for an early discharge strategy. AIMS: We aimed to assess the safety of early discharge (≤2 days) for low-risk STEMI patients treated with primary percutaneous coronary intervention (PCI). METHODS: Using nationwide data from the SWEDEHEART registry, we identified patients with STEMI treated with primary PCI during the period 2009-2017, of whom 8,092 (26.4%) were identified as low risk with the PAMI-II score. Low-risk patients were stratified according to their length of hospital stay (≤2 days vs >2 days). The primary endpoint was major adverse cardiovascular events (MACE, including death, reinfarction treated with PCI, stroke or heart failure hospitalisation) at one year, assessed using a Cox proportional hazards model with propensity score as well as an inverse probability weighting propensity score of average treatment effect to adjust for confounders. RESULTS: A total of 1,449 (17.9%) patients were discharged ≤2 days from admission. After adjustment, the one-year MACE rate was not higher for patients discharged at >2 days from admission than for patients discharged ≤2 days (4.3% vs 3.2%; adjusted HR 1.31, 95% confidence interval [CI]: 0.92-1.87, p=0.14), and no difference was observed regarding any of the individual components of the main outcome. Results were consistent across all subgroups with no difference in MACE between early and late discharge patients. CONCLUSIONS: Nationwide observational data suggest that early discharge of low-risk patients with STEMI treated with PCI is not associated with an increase in one-year MACE.

Targeting S100A9 Reduces Neutrophil Recruitment, Inflammation and Lung Damage in Abdominal Sepsis.

S100A9, a pro-inflammatory alarmin, is up-regulated in inflamed tissues. However, the role of S100A9 in regulating neutrophil activation, inflammation and lung damage in sepsis is not known. Herein, we hypothesized that blocking S100A9 function may attenuate neutrophil recruitment in septic lung injury. Male C57BL/6 mice were pretreated with the S100A9 inhibitor ABR-238901 (10 mg/kg), prior to cercal ligation and puncture (CLP). Bronchoalveolar lavage fluid (BALF) and lung tissue were harvested for analysis of neutrophil infiltration as well as edema and CXC chemokine production. Blood was collected for analysis of membrane-activated complex-1 (Mac-1) expression on neutrophils as well as CXC chemokines and IL-6 in plasma. Induction of CLP markedly increased plasma levels of S100A9. ABR-238901 decreased CLP-induced neutrophil infiltration and edema formation in the lung. In addition, inhibition of S100A9 decreased the CLP-induced up-regulation of Mac-1 on neutrophils. Administration of ABR-238901 also inhibited the CLP-induced increase of CXCL-1, CXCL-2 and IL-6 in plasma and lungs. Our results suggest that S100A9 promotes neutrophil activation and pulmonary accumulation in sepsis. Targeting S100A9 function decreased formation of CXC chemokines in circulation and lungs and attenuated sepsis-induced lung damage. These novel findings suggest that S100A9 plays an important pro-inflammatory role in sepsis and could be a useful target to protect against the excessive inflammation and lung damage associated with the disease.

Transcriptional Profiling and Functional Analysis of N1/N2 Neutrophils Reveal an Immunomodulatory Effect of S100A9-Blockade on the Pro-Inflammatory N1 Subpopulation.

Neutrophils have been classically viewed as a homogenous population. Recently, neutrophils were phenotypically classified into pro-inflammatory N1 and anti-inflammatory N2 sub-populations, but the functional differences between the two subtypes are not completely understood. We aimed to investigate the phenotypic and functional differences between N1 and N2 neutrophils, and to identify the potential contribution of the S100A9 alarmin in neutrophil polarization. We describe distinct transcriptomic profiles and functional differences between N1 and N2 neutrophils. Compared to N2, the N1 neutrophils exhibited: i) higher levels of ROS and oxidative burst, ii) increased activity of MPO and MMP-9, and iii) enhanced chemotactic response. N1 neutrophils were also characterized by elevated expression of NADPH oxidase subunits, as well as activation of the signaling molecules ERK and the p65 subunit of NF-kB. Moreover, we found that the S100A9 alarmin promotes the chemotactic and enzymatic activity of N1 neutrophils. S100A9 inhibition with a specific small-molecule blocker, reduced CCL2, CCL3 and CCL5 chemokine expression and decreased MPO and MMP-9 activity, by interfering with the NF-kB signaling pathway. Together, these findings reveal that N1 neutrophils are pro-inflammatory effectors of the innate immune response. Pharmacological blockade of S100A9 dampens the function of the pro-inflammatory N1 phenotype, promoting the alarmin as a novel target for therapeutic intervention in inflammatory diseases.

S100A9 Links Inflammation and Repair in Myocardial Infarction.

RATIONALE: The alarmin S100A9 has been identified as a potential therapeutic target in myocardial infarction. Short-term S100A9 blockade during the inflammatory phase post-myocardial infarction inhibits systemic and cardiac inflammation and improves cardiac function long term. OBJECTIVE: To evaluate the impact of S100A9 blockade on postischemic cardiac repair. METHODS AND RESULTS: We assessed cardiac function, hematopoietic response, and myeloid phagocyte dynamics in WT (wild type) C57BL/6 mice with permanent coronary artery ligation, treated with the specific S100A9 blocker ABR-238901 for 7 or 21 days. In contrast to the beneficial effects of short-term therapy, extended S100A9 blockade led to progressive deterioration of cardiac function and left ventricle dilation. The treatment reduced the proliferation of Lin-Sca-1+c-Kit+ hematopoietic stem and progenitor cells in the bone marrow and the production of proreparatory CD150+CD48-CCR2+ hematopoietic stem cells. Monocyte trafficking from the spleen to the myocardium and subsequent phenotype switching to reparatory Ly6CloMerTKhi macrophages was also impaired, leading to inefficient efferocytosis, accumulation of apoptotic cardiomyocytes, and a larger myocardial scar. The transcription factor Nur77 (Nr4a1 [nuclear receptor subfamily 4 group A member 1]) mediates the transition from inflammatory Ly6Chi monocytes to reparatory Ly6Clo macrophages. S100A9 upregulated the levels and activity of Nur77 in monocytes and macrophages in vitro and in Ly6Chi/int monocytes in vivo, and S100A9 blockade antagonized these effects. Finally, the presence of reparatory macrophages in the myocardium was also impaired in S100A9-/- mice with permanent myocardial ischemia, leading to depressed cardiac function long term. CONCLUSIONS: We show that S100A9 plays an important role in both the inflammatory and the reparatory immune responses to myocardial infarction. Long-term S100A9 blockade negatively impacts cardiac recovery and counterbalances the beneficial effects of short-term therapy. These results define a therapeutic window targeting the inflammatory phase for optimal effects of S100A9 blockade as potential immunomodulatory treatment in acute myocardial infarction.

Association between attending exercise-based cardiac rehabilitation and cardiovascular risk factors at one-year post myocardial infarction.

BACKGROUND: Randomized trials confirm the benefits of exercise-based cardiac rehabilitation on cardiovascular risk factors. Whether exercise-based cardiac rehabilitation provides the same favourable effects in real-life cardiac rehabilitation settings, in the modern era of myocardial infarction treatment, is less well known. We examined the association between attending exercise-based cardiac rehabilitation and improvements in cardiovascular risk factors at one-year post myocardial infarction in patients included in the Swedish heart disease registry, SWEDEHEART. METHODS: In this retrospective registry-based cohort study, we included 19 136 patients post myocardial infarction (75% men, 62.8±8.7 years) who were registered in SWEDEHEART between 2011 and 2013. The association between attending exercise-based cardiac rehabilitation (43% participation rate) and changes in cardiovascular risk profile between baseline and one-year follow-up was assessed using multivariable regression analysis adjusting for age, comorbidities and medication. RESULTS: Attenders more often reported to have stopped smoking (men 64% vs 50%; women 64% vs 53%, p<0.001 for both, only smokers at baseline considered), be more physically active (men 3.9±2.5 vs 3.4±2.7 days/week; women 3.8±2.6 vs 3.0±2.8 days/week, p<0.001 for both) and achieved a slightly larger reduction in triglycerides (men -0.2±0.8 vs -0.1±0.9 mmol/L, p = 0.001; women -0.1±0.6 vs 0.0±0.8 mmol/L, p = 0.01) at one-year compared to non-attenders. Male attenders gained less weight (+0.0±5.7 vs +0.3±5.7 kg, p = 0.01) while female attenders achieved better lipid control (total cholesterol -1.2±1.4 vs -0.9±1.4 mmol/L, p<0.001; low-density lipoprotein -1.2±1.2 vs -0.9 ±1.2 mmol/L, p<0.001) compared to non-attenders. CONCLUSIONS: In an unselected registry cohort of patients post myocardial infarction, compared to non-attenders those attending exercise-based cardiac rehabilitation achieved significantly larger improvements in cardiovascular risk factors at one-year after the acute event.

Cardiac rehabilitation after acute myocardial infarction in Sweden - evaluation of programme characteristics and adherence to European guidelines: The Perfect Cardiac Rehabilitation (Perfect-CR) study.

BACKGROUND: While patient performance after participating in cardiac rehabilitation programmes after acute myocardial infarction is regularly reported through registry and survey data, information on cardiac rehabilitation programme characteristics is less well described. AIM: The aim of this study was to evaluate Swedish cardiac rehabilitation programme characteristics and adherence to European Guidelines on Cardiovascular Disease Prevention. METHOD: Cardiac rehabilitation programme characteristics at all 78 cardiac rehabilitation centres in Sweden in 2016 were surveyed using a web-based questionnaire (100% response rate). The questions were based on core components of cardiac rehabilitation as recommended by European Guidelines. RESULTS: There was a wide variation in programme duration (2-14 months). All programmes reported offering an individual post-discharge visit with a nurse, and 90% (n = 70) did so within three weeks from discharge. Most programmes offered centre-based exercise training (n = 76, 97%) and group educational sessions (n = 61, 78%). All programmes reported to the national audit, SWEDEHEART, and 60% (n = 47) reported that performance was regularly assessed using audit data, to improve quality of care. Ninety-six per cent (n = 75) had a core team consisting of a cardiologist, a physiotherapist and a nurse and 76% (n = 59) reported having a medical director. Having other allied healthcare professionals included in the cardiac rehabilitation team varied. Forty per cent (n = 31) reported having regular team meetings where nurses, physiotherapists and cardiologist could discuss patient cases. CONCLUSION: The overall quality of cardiac rehabilitation programmes provided in Sweden is high. Still, there are several areas of potential improvement. Monitoring programme characteristics as well as patient outcomes might improve programme quality and patient outcomes both at a local and a national level.

Low Levels of CD4+CD28null T Cells at Baseline Are Associated With First-Time Coronary Events in a Prospective Population-Based Case-Control Cohort.

OBJECTIVE: CD4+CD28null T cells have been shown to be associated with recurrent coronary events and suggested as potential biomarker and therapeutic target. It is unknown whether CD4+CD28null T cells associate with first-time cardiovascular events. We examined CD4+CD28null T cells in a prospective population-based cohort and in patients with advanced atherosclerosis. Approach and Results: CD4+CD28null T cells were quantified in 272 individuals experiencing a first-time coronary event during up to 17 years of follow-up and 272 age- and sex-matched controls in a case-control study, nested within the population-based Malmö Diet and Cancer study. The highest tertile of CD4+CD28null T cells was associated with a lower incidence of first-time coronary events compared with the lowest tertile (odds ratio, 0.48 [95% CI, 0.29-0.79], P=0.004) when adjusting for Framingham risk factors. This association remained significant for events recorded after >9 years of follow-up, when most coronary events occurred, but not during the first 9 years of follow-up, despite similar odds ratio. Additionally, we analyzed CD4+CD28null T cells in 201 patients with advanced atherosclerosis undergoing carotid endarterectomy. The adjusted hazard ratio for cardiovascular events in patients with advanced atherosclerosis was 2.11 (95% CI, 1.10-4.05, P=0.024), comparing the highest with the lowest CD4+CD28null T-cell tertile. CONCLUSIONS: Our findings reveal complex associations between CD4+CD28null T cells and cardiovascular disease. Although we confirm the reported positive associations with an adverse prognosis in patients with already established disease, the opposite associations with first-time coronary events in the population-based cohort may limit the clinical use of CD4+CD28null T cells.

Circulating Monocyte Chemoattractant Protein-1 and Risk of Stroke: Meta-Analysis of Population-Based Studies Involving 17 180 Individuals.

Rationale: Proinflammatory cytokines have been identified as potential targets for lowering vascular risk. Experimental evidence and Mendelian randomization suggest a role of MCP-1 (monocyte chemoattractant protein-1) in atherosclerosis and stroke. However, data from large-scale observational studies are lacking. Objective: To determine whether circulating levels of MCP-1 are associated with risk of incident stroke in the general population. Methods and Results: We used previously unpublished data on 17 180 stroke-free individuals (mean age, 56.7±8.1 years; 48.8% men) from 6 population-based prospective cohort studies and explored associations between baseline circulating MCP-1 levels and risk of any stroke, ischemic stroke, and hemorrhagic stroke during a mean follow-up interval of 16.3 years (280 522 person-years at risk; 1435 incident stroke events). We applied Cox proportional-hazards models and pooled hazard ratios (HRs) using random-effects meta-analyses. After adjustments for age, sex, race, and vascular risk factors, higher MCP-1 levels were associated with increased risk of any stroke (HR per 1-SD increment in ln-transformed MCP-1, 1.07; 95% CI, 1.01-1.14). Focusing on stroke subtypes, we found a significant association between baseline MCP-1 levels and higher risk of ischemic stroke (HR, 1.11 [1.02-1.21]) but not hemorrhagic stroke (HR, 1.02 [0.82-1.29]). The results followed a dose-response pattern with a higher risk of ischemic stroke among individuals in the upper quartiles of MCP-1 levels as compared with the first quartile (HRs, second quartile: 1.19 [1.00-1.42]; third quartile: 1.35 [1.14-1.59]; fourth quartile: 1.38 [1.07-1.77]). There was no indication for heterogeneity across studies, and in a subsample of 4 studies (12 516 individuals), the risk estimates were stable after additional adjustments for circulating levels of IL (interleukin)-6 and high-sensitivity CRP (C-reactive protein). Conclusions: Higher circulating levels of MCP-1 are associated with increased long-term risk of stroke. Our findings along with genetic and experimental evidence suggest that MCP-1 signaling might represent a therapeutic target to lower stroke risk.Visual Overview: An online visual overview is available for this article.

Inhibition of pro-inflammatory myeloid cell responses by short-term S100A9 blockade improves cardiac function after myocardial infarction.

AIMS: Neutrophils have both detrimental and beneficial effects in myocardial infarction (MI), but little is known about the underlying pathways. S100A8/A9 is a pro-inflammatory alarmin abundantly expressed in neutrophils that is rapidly released in the myocardium and circulation after myocardial ischaemia. We investigated the role of S100A8/A9 in the innate immune response to MI. METHODS AND RESULTS: In 524 patients with acute coronary syndrome (ACS), we found that high plasma S100A8/A9 at the time of the acute event was associated with lower left ventricular ejection fraction (EF) at 1-year and increased hospitalization for heart failure (HF) during follow-up. In wild-type C57BL/6 mice with MI induced by permanent coronary artery ligation, treatment with the S100A9 blocker ABR-238901 during the inflammatory phase of the immune response inhibited haematopoietic stem cell proliferation and myeloid cell egression from the bone marrow. The treatment reduced the numbers of neutrophils and monocytes/macrophages in the myocardium, promoted an anti-inflammatory environment, and significantly improved cardiac function compared with MI controls. To mimic the clinical scenario, we further confirmed the effects of the treatment in a mouse model of ischaemia/reperfusion. Compared with untreated mice, 3-day ABR-238901 treatment significantly improved left ventricular EF (48% vs. 35%, P = 0.002) and cardiac output (15.7 vs. 11.1 mL/min, P = 0.002) by Day 21 post-MI. CONCLUSION: Short-term S100A9 blockade inhibits inflammation and improves cardiac function in murine models of MI. As an excessive S100A8/A9 release is linked to incident HF, S100A9 blockade might represent a feasible strategy to improve prognosis in ACS patients.