Oxidation-reduction imaging of myoglobin reveals two-phase oxidation in the reperfused myocardium.

Myocardial infarction (MI) is a serious acute cardiovascular syndrome that causes myocardial injury due to blood flow obstruction to a specific myocardial area. Under ischemic-reperfusion settings, a burst of reactive oxygen species is generated, leading to redox imbalance that could be attributed to several molecules, including myoglobin. Myoglobin is dynamic and exhibits various oxidation-reduction states that have been an early subject of attention in the food industry, specifically for meat consumers. However, rarely if ever have the myoglobin optical properties been used to measure the severity of MI. In the current study, we develop a novel imaging pipeline that integrates tissue clearing, confocal and light sheet fluorescence microscopy, combined with imaging analysis, and processing tools to investigate and characterize the oxidation-reduction states of myoglobin in the ischemic area of the cleared myocardium post-MI. Using spectral imaging, we have characterized the endogenous fluorescence of the myocardium and demonstrated that it is partly composed by fluorescence of myoglobin. Under ischemia-reperfusion experimental settings, we report that the infarcted myocardium spectral signature is similar to that of oxidized myoglobin signal that peaks 3 h post-reperfusion and decreases with cardioprotection. The infarct size assessed by oxidation-reduction imaging at 3 h post-reperfusion was correlated to the one estimated with late gadolinium enhancement MRI at 24 h post-reperfusion. In conclusion, this original work suggests that the redox state of myoglobin can be used as a promising imaging biomarker for characterizing and estimating the size of the MI during early phases of reperfusion.

Impact of Age on Systemic Inflammatory Profile of Patients With ST-Segment-Elevation Myocardial Infarction and Acute Ischemic Stroke.

BACKGROUND: Aging is associated with a chronic low-grade inflammatory state. This condition may affect the acute inflammatory response involved in ST-segment-elevation myocardial infarction (STEMI) or acute ischemic stroke (AIS). We sought to compare the profile of a set of circulating inflammatory markers between young and older patients admitted for STEMI or AIS. METHODS: HIBISCUS-STEMI (Cohort of Patients to Identify Biological and Imaging Markers of Cardiovascular Outcomes in ST Elevation Myocardial Infarction) and HIBISCUS-STROKE (Cohort of Patients to Identify Biological and Imaging Markers of Cardiovascular Outcomes in Stroke) are 2 cohort studies that enrolled patients with STEMI treated with primary percutaneous coronary intervention in the cardiac intensive care unit of Lyon and patients with AIS treated with mechanical thrombectomy in the Lyon Stroke Center, respectively from 2016 to 2019. Patients were classified as older if they were ≥65 years and as young if they were <65 years. In both cohorts, CRP (C-reactive protein), IL (interleukin)-6, IL-8, IL-10, MCP (monocyte chemoattractant protein), sTNF-RI (soluble tumor necrosis factor receptor I), sST2 (soluble form suppression of tumorigenicity 2), and VCAM-1 (vascular cellular adhesion molecule-1) were measured on serum collected at 5 time points using enzyme-linked immunosorbent assay. A multiple logistic regression model was performed to detect an association between area under the curve of circulating inflammatory markers within the first 48 hours and older age. RESULTS: A total of 260 patients with STEMI and 164 patients with AIS were included. Of them, there were 76 (29%) and 105 (64%) older patients with STEMI and AIS, respectively. Following multivariable analysis, a high area under the curve of IL-6 and sTNF-RI, a low lymphocyte count, and a high neutrophil-lymphocyte ratio at 24 hours were associated with older age in patients with STEMI and AIS. CONCLUSIONS: Older patients had higher IL-6 and sTFN-RI levels within the first 48 hours associated with a lower lymphocyte count and a higher neutrophil-lymphocyte ratio at 24 hours in both cohorts.

Simultaneous assessment of microcalcifications and morphological criteria of vulnerability in carotid artery plaque using hybrid 18F-NaF PET/MRI.

BACKGROUND: Previous studies have suggested the role of microcalcifications in plaque vulnerability. This exploratory study sought to assess the potential of hybrid positron-emission tomography (PET)/magnetic resonance imaging (MRI) using 18F-sodium fluoride (18F-NaF) to check simultaneously 18F-NaF uptake, a marker of microcalcifications, and morphological criteria of vulnerability. METHODS AND RESULTS: We included 12 patients with either recently symptomatic or asymptomatic carotid stenosis. All patients underwent 18F-NaF PET/MRI. 18F-NaF target-to-background ratio (TBR) was measured in culprit and nonculprit (including contralateral plaques of symptomatic patients) plaques as well as in other arterial walls. Morphological criteria of vulnerability were assessed on MRI. Mineral metabolism markers were also collected. 18F-NaF uptake was higher in culprit compared to nonculprit plaques (median TBR 2.6 [2.2-2.8] vs 1.7 [1.3-2.2]; P = 0.03) but was not associated with morphological criteria of vulnerability on MRI. We found a positive correlation between 18F-NaF uptake and calcium plaque volume and ratio but not with circulating tissue-nonspecific alkaline phosphatase (TNAP) activity and inorganic pyrophosphate (PPi) levels. 18F-NaF uptake in the other arterial walls did not differ between symptomatic and asymptomatic patients. CONCLUSIONS: 18F-NaF PET/MRI may be a promising tool for providing additional insights into the plaque vulnerability.

Large vessel cardioembolic stroke and embolic stroke of undetermined source share a common profile of matrix metalloproteinase-9 level and susceptibility vessel sign length.

BACKGROUND: Embolic stroke of undetermined source (ESUS) accounts for up to 25% of ischemic strokes. Identification of biomarkers that could improve the prediction of stroke subtype and subsequently of stroke prevention still remains a major issue. METHODS: The HIBISCUS-STROKE cohort includes ischemic stroke patients with large vessel occlusion treated with mechanical thrombectomy following admission magnetic resonance imaging. Presence and length of susceptibility vessel sign (SVS) were assessed by gradient-recalled echo T2*-weighted imaging. Matrix metalloproteinase-9 (MMP-9) was measured on sera collected at admission. A multiple logistic regression model was performed to detect independent markers distinguishing cardioembolic (CE) from large-artery atherosclerosis (LAA) subtype. RESULTS: A total of 147 patients were included, of them the etiology was distributed as follows: 86 (58.5%) CE, 26 (17.7%) LAA, and 35 (23.8%) ESUS. The optimal cutoff for differentiating CE from LAA subtype was 14.5 mm for SVS length (sensitivity, 79.7%; specificity, 72.7%) and 1110 ng/ml for admission MMP-9 level (sensitivity, 85.3%; specificity, 52.2%). Multivariate analysis revealed that current smoking (odds ratio [OR] 0.07, 95% confidence interval [CI] 0.01-0.93), tandem occlusion (OR 0.01, 95% CI 0.01-0.21), SVS length (OR 0.78, 95% CI 0.63-0.97), and admission MMP-9 level (OR 0.99, 95% CI 0.99-1.00) were inversely associated with CE subtype. SVS length and MMP-9 level did not differ between ESUS and CE subtypes. CONCLUSION: SVS length and admission MMP-9 level may improve the prediction of CE subtype whose profile is close to ESUS, thus suggesting a common cardiac embolic source.

An innovative sequence of hypoxia-reoxygenation on adult mouse cardiomyocytes in suspension to perform multilabeling analysis by flow cytometry.

Cardiovascular diseases remain the leading cause of death worldwide. Although major therapeutic progress has been made during the past decades, a better understanding of the underlying mechanisms will certainly help to improve patient's prognosis. In vitro models, particularly adult mouse cardiomyocytes, have been largely used; however, their fragility and large size are major obstacles to the use of flow cytometry. Conventional techniques, such as cell imaging, require the use of large numbers of animals and are time consuming. Here, we described a new, simple, and rapid one-day protocol using living adult mouse cardiomyocytes in suspension exposed to hypoxia-reoxygenation that allows a multilabeling analysis by flow cytometry. Several parameters can be measured by fluorescent probes labeling to assess cell viability (propidium iodide, calcein-AM, and Sytox Green), mitochondrial membrane potential [DilC1(5) and TMRM], reactive oxygen species production (MitoSOX Red), and mitochondrial mass (MitoTracker Deep Red). We address the robustness and sensitivity of our model using a cardioprotective agent, cyclosporine A. Overall, our new experimental set-up offers a high-speed quantitative multilabeling analysis of adult mouse cardiomyocytes exposed to hypoxia-reoxygenation. Our model might be interesting to investigate other cellular stresses (oxidative and inflammation) or to perform pharmacological screening.

Matrix Metalloproteinase-9 and Monocyte Chemoattractant Protein-1 Are Associated With Collateral Status in Acute Ischemic Stroke With Large Vessel Occlusion.

BACKGROUND AND PURPOSE: In ischemic stroke, inflammatory status may condition the development of collateral circulation. Here we assessed the relationship between systemic inflammatory biomarkers and collateral status in large vessel occlusion before mechanical thrombectomy. METHODS: HIBISCUS-STROKE is a cohort study including acute ischemic stroke patients with large vessel occlusion treated with mechanical thrombectomy following admission magnetic resonance imaging. MMP-9 (matrix metalloproteinase-9) and MCP-1 (monocyte chemoattractant protein-1) were measured on blood sampling collected at admission. Collateral status was assessed on pretreatment Digital subtraction angiography and categorized into poor (Higashida score, 0-2) and good (Higashida score, 3-4). A multiple logistic regression model was performed to detect independent markers of good collateral status. RESULTS: One hundred and twenty-two patients were included, of them 71 patients (58.2%) had a good collateral status. In univariate analysis, low MMP-9 levels (P=0.01), high MCP-1 levels (P<0.01), a low National Institute of Health Stroke Score (P=0.046), a high diastolic blood pressure (P=0.049), the absence of tandem occlusion (P=0.046), a high Alberta Stroke Program Early CT Score (P<0.01) and a low volume on the diffusion-weighted imaging (P<0.01) were associated with good collateral status. Following multivariate analysis, low MMP-9 levels (P=0.02) and high MCP-1 levels (P<0.01) remained associated with good collateral status. CONCLUSIONS: Low MMP-9 and high MCP-1 levels were associated with good pretreatment collateral status in patients with acute ischemic stroke with large vessel occlusion. These results might suggest a relationship between collateral status and inflammation.

Deleterious Anti-Inflammatory Macrophage Recruitment in Early Post-Infarction Phase: Unraveling the IL-6/MCP-1/STAT3 Axis.

Using a translational approach with an ST-segment myocardial infarction (STEMI) cohort and mouse model of myocardial infarction, we highlighted the role of the secreted IL-6 and MCP-1 cytokines and the STAT3 pathway in heart macrophage recruitment and activation. Cardiac myocytes secrete IL-6 and MCP-1 in response to hypoxic stress, leading to a recruitment and/or polarization of anti-inflammatory macrophages via the STAT3 pathway. In our preclinical model of myocardial infarction, neutralization of IL-6 and MCP-1 or STAT3 pathway reduced infarct size. Together, our data demonstrate that anti-inflammatory macrophages can be deleterious in the acute phase of STEMI.

Therapeutic Spp1 silencing in TREM2+ cardiac macrophages suppresses atrial fibrillation.

Atrial fibrillation (AFib) and the risk of its lethal complications are propelled by fibrosis, which induces electrical heterogeneity and gives rise to reentry circuits. Atrial TREM2+ macrophages secrete osteopontin (encoded by Spp1), a matricellular signaling protein that engenders fibrosis and AFib. Here we show that silencing Spp1 in TREM2+ cardiac macrophages with an antibody-siRNA conjugate reduces atrial fibrosis and suppresses AFib in mice, thus offering a new immunotherapy for the most common arrhythmia.

Specific inflammatory profile of acute ischemic stroke patients with left atrial enlargement.

Background: The inflammatory process underlying atrial myopathy may affect the inflammatory response activated in acute ischemic stroke (AIS). Objectives: We aimed to assess whether left atrial enlargement (LAE) as a marker of atrial myopathy is associated with a different profile of circulating inflammatory markers in AIS patients. Methods: HIBISCUS-STROKE is a cohort study including anterior circulation AIS patients treated with mechanical thrombectomy following MRI. Ten circulating inflammatory markers were measured at admission and 6, 24, and 48 h after admission. LAE was defined as a left atrial volume index (LAVi) ≥34 ml/m2. A multiple logistic regression model was performed to detect an independent association between the area under the curve (AUC) of these markers and LAE. Results: We included 143 patients. Of them, 85 (59.4%) had LAE. On univariable analysis, we found that patients with LAE had higher soluble form suppression of tumorigenicity 2 (sST2), soluble tumor necrosis factor receptor I (sTNFR1), and vascular cellular adhesion molecule-1 (VCAM-1) AUC, were older, mostly female, had a higher National Institutes of Health Stroke Scale (NIHSS) score and blood glucose level at admission, had more often hypertension, and a cardioembolic source of AIS, such as atrial fibrillation, while they were less frequently current smokers and had a lower rate of tandem occlusion than patients without LAE. On multivariable analysis, we found that among circulating inflammatory markers, only high VCAM-1 (OR: 9.13, 95% CI: 3.21-25.9) and sST2 (OR: 3.40, 95% CI: 1.68-6.86) AUC remained associated with LAE. Conclusions: High VCAM-1 and sST2 levels within the first 48 h are associated with LAE in AIS patients.

Recruited macrophages elicit atrial fibrillation.

Atrial fibrillation disrupts contraction of the atria, leading to stroke and heart failure. We deciphered how immune and stromal cells contribute to atrial fibrillation. Single-cell transcriptomes from human atria documented inflammatory monocyte and SPP1+ macrophage expansion in atrial fibrillation. Combining hypertension, obesity, and mitral valve regurgitation (HOMER) in mice elicited enlarged, fibrosed, and fibrillation-prone atria. Single-cell transcriptomes from HOMER mouse atria recapitulated cell composition and transcriptome changes observed in patients. Inhibiting monocyte migration reduced arrhythmia in Ccr2-∕- HOMER mice. Cell-cell interaction analysis identified SPP1 as a pleiotropic signal that promotes atrial fibrillation through cross-talk with local immune and stromal cells. Deleting Spp1 reduced atrial fibrillation in HOMER mice. These results identify SPP1+ macrophages as targets for immunotherapy in atrial fibrillation.

Bone marrow adipocytes fuel emergency hematopoiesis after myocardial infarction.

After myocardial infarction (MI), emergency hematopoiesis produces inflammatory myeloid cells that accelerate atherosclerosis and promote heart failure. Since the balance between glycolysis and mitochondrial metabolism regulates hematopoietic stem cell homeostasis, metabolic cues may influence emergency myelopoiesis. Here, we show in humans and female mice that hematopoietic progenitor cells increase fatty acid metabolism after MI. Blockade of fatty acid oxidation by deleting carnitine palmitoyltransferase (Cpt1A) in hematopoietic cells of Vav1Cre/+Cpt1Afl/fl mice limited hematopoietic progenitor proliferation and myeloid cell expansion after MI. We also observed reduced bone marrow adiposity in humans, pigs and mice following MI. Inhibiting lipolysis in adipocytes using AdipoqCreERT2Atglfl/fl mice or local depletion of bone marrow adipocytes in AdipoqCreERT2iDTR mice also curbed emergency hematopoiesis. Furthermore, systemic and regional sympathectomy prevented bone marrow adipocyte shrinkage after MI. These data establish a critical role for fatty acid metabolism in post-MI emergency hematopoiesis.

A lower admission level of interleukin-6 is associated with first-pass effect in ischemic stroke patients.

BACKGROUND: First-pass effect (FPE) defined as a complete or near-complete reperfusion achieved after a single thrombectomy pass is predictive of favorable outcome in acute ischemic stroke (AIS) patients. We aimed to assess whether admission levels of inflammatory markers are associated with FPE. METHODS: HIBISCUS-STROKE (CoHort of Patients to Identify Biological and Imaging markerS of CardiovascUlar Outcomes in Stroke) includes AIS patients with large vessel occlusion treated with mechanical thrombectomy following brain MRI. C-reactive protein, interleukin (IL)-6, IL-8, IL-10, monocyte chemoattractant protein-1, soluble tumor necrosis factor receptor I, soluble form suppression of tumorigenicity 2, matrix metalloproteinase-9 (MMP-9), soluble P-selectin, and vascular cellular adhesion molecule-1 were measured in admission sera using an ELISA assay. FPE was defined as a complete or near-complete reperfusion (thrombolysis in cerebral infarction scale (TICI) 2c or 3) after the first pass. A multivariate logistic regression analysis was performed to assess independent factors associated with FPE. RESULTS: A total of 151 patients were included. Among them, 43 (28.5%) patients had FPE. FPE was associated with low admission levels of IL-6, MMP-9, and platelet count, an older age, lack of hypertension, lack of tandem occlusion, a shorter thrombus length, and a reduced procedural time. Following multivariate analysis, a low admission level of IL-6 was associated with FPE (OR 0.66, 95% CI 0.46 to 0.94). Optimal cut-off of IL-6 level for distinguishing FPE from non-FPE was 3.0 pg/mL (sensitivity 92.3%, specificity 42.3%). CONCLUSION: A lower admission level of IL-6 is associated with FPE.

Prognosis value of serum soluble ST2 level in acute ischemic stroke and STEMI patients in the era of mechanical reperfusion therapy.

BACKGROUND: Soluble form suppression of tumorigenicity 2 (sST2) is known to have prognostic value in ST-elevation myocardial infarction (STEMI) and could impact mortality after acute ischemic stroke (AIS). However, before considering sST2 as a therapeutic target, the kinetics of release and its association with adverse clinical events in both STEMI and AIS patients have to be determined. METHODS: We prospectively enrolled 251 STEMI patients, treated with primary percutaneous coronary intervention, and 152 AIS patients treated with mechanical thrombectomy. We evaluated the level of sST2 in patient sera at five time point (admission, 4, 24, 48 h and 1 month from admission for STEMI patients and admission, 6, 24, 48 h and 3 months from admission for AIS patients). Major adverse clinical events (MACE) (all-cause death, acute myocardial infarction, stroke or hospitalization for heart failure) in STEMI patients and all-cause death in AIS patients were recorded during a 12-month follow-up. RESULTS: Mean age of the study population was 59 ± 12 and 69 ± 15 years in STEMI and AIS patients, respectively. In STEMI patients, sST2 peaked 24 h after admission (25.5 ng/mL interquartile range (IQR) [14.9-29.1]) whereas an earlier and lower peak was observed in AIS patients (16.8 ng/mL IQR [15.2-18.3] at 6 h). Twenty-five (10.0%) STEMI patients experienced a MACE and 12 (7.9%) AIS patients had all-cause death within the first 12 months. A high level of sST2 at 24 h was associated with MACE in STEMI patients (hazard ratio (HR) = 2.5; 95% confidence interval (CI) [1.1-5.6], p = 0.03) and all-cause death in AIS patients (HR = 11.7; 95% CI [3.8-36.2], p < 0.01) within the first 12 months. CONCLUSIONS: The study highlights that sST2 levels at 24 h are associated with an increased risk to adverse clinical events in both diseases.

Inflammatory profile and white matter hyperintensity burden in acute ischemic stroke patients.

Inflammation is involved in small vessel disease (SVD). We aim to clarify whether inflammation related to white matter hyperintensities (WMH), a key component of SVD, may affect the inflammatory response in acute ischemic stroke (AIS) patients. For this, we sequentially measured 10 circulating inflammatory markers and assessed WMH burden on admission MRI in AIS patients treated with thrombectomy. Of 149 patients, 57 (38.3%) had a high WMH burden (Fazekas≥3). A high WMH burden was associated with 4 markers levels but this association did not remain following multivariable analyses. WMH burden is not associated with a specific inflammatory profile in AIS.

Association of Blood Biomarkers of Inflammation With Penumbra Consumption After Mechanical Thrombectomy in Patients With Acute Ischemic Stroke.

BACKGROUND AND OBJECTIVES: The objective of this study was to assess the relationship between blood biomarkers of inflammation and lesion growth within the penumbra in acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT). METHODS: The HIBISCUS-STROKE cohort enrolled patients admitted in the Lyon Stroke Center for an anterior circulation AIS treated with MT after brain MRI assessment. Lesion growth within the penumbra was assessed on day 6 MRI using a voxel-based nonlinear coregistration method and dichotomized into low and high according to the median value. C-reactive protein, interleukin (IL)-6, IL-8, IL-10, monocyte chemoattractant protein-1, soluble tumor necrosis factor receptor I, soluble form suppression of tumorigenicity 2 (sST2), soluble P-selectin, vascular cellular adhesion molecule-1, and matrix metalloproteinase-9 were measured in sera at 4 time points within the first 48 hours. Reperfusion was considered as successful if Thrombolysis in Cerebral Infarction score was 2b/2c/3. A multiple logistic regression model was performed to detect any association between area under the curve (AUC) of these biomarkers within the first 48 hours and a high lesion growth within the penumbra. RESULTS: Ninety patients were included. The median lesion growth within the penumbra was 2.3 (0.7-6.2) mL. On multivariable analysis, a high sST2 AUC (OR 3.77, 95% CI 1.36-10.46), a high baseline DWI volume (OR 3.65, 95% CI 1.32-10.12), and a lack of successful reperfusion (OR 0.19, 95% CI 0.04-0.92) were associated with a high lesion growth within the penumbra. When restricting analyses to patients with successful reperfusion (n = 76), a high sST2 AUC (OR 5.03, 95% CI 1.64-15.40), a high baseline DWI volume (OR 3.74, 95% CI 1.22-11.53), and a high penumbra volume (OR 3.25, 95% CI 1.10-9.57) remained associated with a high lesion growth within the penumbra. DISCUSSION: High sST2 levels within the first 48 hours are associated with a high lesion growth within the penumbra.

Brain virtual histology with X-ray phase-contrast tomography Part I: whole-brain myelin mapping in white-matter injury models.

White-matter injury leads to severe functional loss in many neurological diseases. Myelin staining on histological samples is the most common technique to investigate white-matter fibers. However, tissue processing and sectioning may affect the reliability of 3D volumetric assessments. The purpose of this study was to propose an approach that enables myelin fibers to be mapped in the whole rodent brain with microscopic resolution and without the need for strenuous staining. With this aim, we coupled in-line (propagation-based) X-ray phase-contrast tomography (XPCT) to ethanol-induced brain sample dehydration. We here provide the proof-of-concept that this approach enhances myelinated axons in rodent and human brain tissue. In addition, we demonstrated that white-matter injuries could be detected and quantified with this approach, using three animal models: ischemic stroke, premature birth and multiple sclerosis. Furthermore, in analogy to diffusion tensor imaging (DTI), we retrieved fiber directions and DTI-like diffusion metrics from our XPCT data to quantitatively characterize white-matter microstructure. Finally, we showed that this non-destructive approach was compatible with subsequent complementary brain sample analysis by conventional histology. In-line XPCT might thus become a novel gold-standard for investigating white-matter injury in the intact brain. This is Part I of a series of two articles reporting the value of in-line XPCT for virtual histology of the brain; Part II shows how in-line XPCT enables the whole-brain 3D morphometric analysis of amyloid- ß (A ß ) plaques.

Cerebrospinal fluid can exit into the skull bone marrow and instruct cranial hematopoiesis in mice with bacterial meningitis.

Interactions between the immune and central nervous systems strongly influence brain health. Although the blood-brain barrier restricts this crosstalk, we now know that meningeal gateways through brain border tissues facilitate intersystem communication. Cerebrospinal fluid (CSF), which interfaces with the glymphatic system and thereby drains the brain's interstitial and perivascular spaces, facilitates outward signaling beyond the blood-brain barrier. In the present study, we report that CSF can exit into the skull bone marrow. Fluorescent tracers injected into the cisterna magna of mice migrate along perivascular spaces of dural blood vessels and then travel through hundreds of sub-millimeter skull channels into the calvarial marrow. During meningitis, bacteria hijack this route to invade the skull's hematopoietic niches and initiate cranial hematopoiesis ahead of remote tibial sites. As skull channels also directly provide leukocytes to meninges, the privileged sampling of brain-derived danger signals in CSF by regional marrow may have broad implications for inflammatory neurological disorders.

Myocardial Ischemia-Reperfusion and Diabetes: Lessons Learned From Bedside to Bench.

In front of the failure to translate from bench to bedside cardioprotective drugs against myocardial ischemia-reperfusion, research scientists are currently revising their animal models. Owing to its growing incidence nowadays, type 2 diabetes (T2D) represents one of the main risk factors of co-morbidities in myocardial infarction. However, discrepancies exist between reported animal and human studies. Our aim was here to compare the impact of diabetes on cell death after cardiac ischemia-reperfusion in a human cohort of ST-elevation myocardial infarction (STEMI) patients with a diet-induced mouse model of T2D, using a high-fat high-sucrose diet for 16 weeks (HFHSD). Interestingly, a small fraction (<14%) of patients undergoing a myocardial infarct were diabetic, but treated, and did not show a bigger infarct size when compared to non-diabetic patients. On the contrary, HFHSD mice displayed an increased infarct size after an in vivo cardiac ischemia-reperfusion, together with an increased cell death after an in vitro hypoxia-reoxygenation on isolated cardiomyocytes. To mimic the diabetic patients' medication profile, 6 weeks of oral gavage with Metformin was performed in the HFHSD mouse group. Metformin treatment of the HFHSD mice led to a similar extent of lower cell death after hypoxia-reoxygenation as in the standard diet group, compared to the HFHSD cardiomyocytes. Altogether, our data highlight that due to their potential protective effect, anti-diabetic medications should be included in pre-clinical study of cardioprotective approaches. Moreover, since diabetic patients represent only a minor fraction of the STEMI patients, diabetic animal models may not be the most suitable translatable model to humans, unlike aging that appears as a common feature of all infarcted patients.

Association of Interleukin-6 Levels and Futile Reperfusion After Mechanical Thrombectomy.

OBJECTIVE: To assess whether interleukin-6 (IL-6) level is a marker of futile reperfusion in patients with acute ischemic stroke (AIS) with large vessel occlusion treated with mechanical thrombectomy (MT). METHODS: The Cohort of Patients to Identify Biological and Imaging Markers of Cardiovascular Outcomes in Stroke (HIBISCUS-STROKE) includes patients with AIS treated with MT after MRI. We performed a sequential assessment of IL-6 (admission, 6 hours, 24 hours, 48 hours and 3 months from admission). Among patients with successful reperfusion (Thrombolysis in Cerebral Infarction scale 2b/3), reperfusion was considered effective if 3-month modified Rankin Scale (mRS) score was 0 to 2 and futile if 3-month mRS score was 3 to 6. Our model was adjusted for the main confounding variables. RESULTS: One hundred sixty-four patients represent the study population. One hundred thirty-three patients had successful reperfusion (81.1%), while in 46 (34.6%), reperfusion was classified as futile. In single-variable analyses, high IL-6 levels at 6, 24, and 48 hours in combination with a higher age, a prestroke mRS score >2, a history of hypertension or diabetes, lack of current smoking, a higher baseline NIH Stroke Scale score, the absence of associated intravenous thrombolysis, an intracranial internal carotid artery or a tandem occlusion, and an increased infarct growth were associated with futile reperfusion. After multivariable analyses, a high IL-6 level at 24 hours (odds ratio 6.15, 95% confidence interval 1.71-22.10) remained associated with futile reperfusion. CONCLUSIONS: IL-6 is a marker of futile reperfusion in the setting of MT.

Serum Soluble Tumor Necrosis Factor Receptors 1 and 2 Are Early Prognosis Markers After ST-Segment Elevation Myocardial Infarction.

Background: As inflammation following ST-segment elevation myocardial infarction (STEMI) is both beneficial and deleterious, there is a need to find new biomarkers of STEMI severity. Objective: We hypothesized that the circulating concentration of the soluble tumor necrosis factor α receptors 1 and 2 (sTNFR1 and sTNFR2) might predict clinical outcomes in STEMI patients. Methods: We enrolled into a prospective cohort 251 consecutive STEMI patients referred to our hospital for percutaneous coronary intervention revascularization. Blood samples were collected at five time points: admission and 4, 24, 48 h, and 1 month after admission to assess sTNFR1 and sTNFR2 serum concentrations. Patients underwent cardiac magnetic resonance imaging at 1 month. Results: sTNFR1 concentration increased at 24 h with a median of 580.5 pg/ml [95% confidence interval (CI): 534.4-645.6]. sTNFR2 increased at 48 h with a median of 2,244.0 pg/ml [95% CI: 2090.0-2,399.0]. Both sTNFR1 and sTNFR2 peak levels were correlated with infarct size and left ventricular end-diastolic volume and inversely correlated with left ventricular ejection fraction. Patients with sTNFR1 or sTNFR2 concentration above the median value were more likely to experience an adverse clinical event within 24 months after STEMI [hazards ratio (HR): 8.8, 95% CI: 4.2-18.6, p < 0.0001 for sTNFR1; HR: 6.1, 95% CI: 2.5 -10.5, p = 0.0003 for sTNFR2]. Soluble TNFR1 was an independent predictor of major adverse cardiovascular events and was more powerful than troponin I (p = 0.04 as compared to the troponin AUC). Conclusion: The circulating sTNFR1 and sTNFR2 are inflammatory markers of morphological and functional injury after STEMI. sTNFR1 appears as an early independent predictor of clinical outcomes in STEMI patients.