Platelet lipidomics and de novo lipogenesis: impact on health and disease.

PURPOSE OF REVIEW: Lipids play vital roles in platelet structure, signaling, and metabolism. In addition to capturing exogenous lipids, platelets possess the capacity for de novo lipogenesis, regulated by acetyl-coA carboxylase 1 (ACC1). This review aims to cover the critical roles of platelet de novo lipogenesis and lipidome in platelet production, function, and diseases. RECENT FINDINGS: Upon platelet activation, approximately 20% of the platelet lipidome undergoes significant modifications, primarily affecting arachidonic acid-containing species. Multiple studies emphasize the impact of de novo lipogenesis, with ACC1 as key player, on platelet functions. Mouse models suggest the importance of the AMPK-ACC1 axis in regulating platelet membrane arachidonic acid content, associated with TXA 2 secretion, and thrombus formation. In human platelets, ACC1 inhibition leads to reduced platelet reactivity. Remodeling of the platelet lipidome, alongside with de novo lipogenesis, is also crucial for platelet biogenesis. Disruptions in the platelet lipidome are observed in various pathological conditions, including cardiovascular and inflammatory diseases, with associations between these alterations and shifts in platelet reactivity highlighted. SUMMARY: The platelet lipidome, partially regulated by ACC-driven de novo lipogenesis, is indispensable for platelet production and function. It is implicated in various pathological conditions involving platelets.

Fibroblasts and platelets: a face-to-face dialogue at the heart of cardiac fibrosis.

Myocardial fibrosis is a feature found in most cardiac diseases and a key element contributing to heart failure and its progression. It has therefore become a subject of particular interest in cardiac research. Mechanisms leading to pathological cardiac remodeling and heart failure are diverse, including effects on cardiac fibroblasts, the main players in cardiac extracellular matrix synthesis, but also on cardiomyocytes, immune cells, endothelial cells, and more recently, platelets. Although transforming growth factor-ß (TGF-ß) is a primary regulator of fibrosis development, the cellular and molecular mechanisms that trigger its activation after cardiac injury remain poorly understood. Different types of anti-TGF-ß drugs have been tested for the treatment of cardiac fibrosis and have been associated with side effects. Therefore, a better understanding of these mechanisms is of great clinical relevance and could allow us to identify new therapeutic targets. Interestingly, it has been shown that platelets infiltrate the myocardium at an early stage after cardiac injury, producing large amounts of cytokines and growth factors. These molecules can directly or indirectly regulate cells involved in the fibrotic response, including cardiac fibroblasts and immune cells. In particular, platelets are known to be a major source of TGF-ß1. In this review, we have provided an overview of the classical cellular effectors involved in the pathogenesis of cardiac fibrosis, focusing on the emergent role of platelets, while discussing opportunities for novel therapeutic interventions.

Laboratory Testing for Endocrine Hypertension: Current and Future Perspectives.

BACKGROUND: Secondary hypertension (SH) is a form of high blood pressure caused by an identifiable underlying condition. Although, it accounts for a small fraction of the overall hypertensive population, detection and management of SH is of utmost importance, because SH phenotypes carry a high cardiovascular risk and can possibly be cured by timely treatment. CONTENT: This review focuses on the endocrine causes of SH, such as primary aldosteronism, Cushing syndrome, thyroid disease, pheochromocytoma and paraganglioma, acromegaly, and rare monogenic forms. It discusses current biomarkers, analytical methods, and diagnostic strategies, highlighting advantages and limitations of each approach. It also explores the emerging -omics technologies that can provide a comprehensive and multidimensional assessment of SH and its underlying mechanisms. SUMMARY: Endocrine SH is a heterogeneous and complex condition that requires proper screening and confirmatory tests to avoid diagnostic delays and improve patient outcomes. Careful biomarker interpretation is essential due to potential interferences, variability, and method-dependent differences. Liquid chromatography-tandem mass spectrometry is a superior method for measuring low-concentration hormones and metabolites involved in SH, but it requires expertise. Omics approaches have great potential to identify novel biomarkers, pathways, and targets for SH diagnosis and treatment, especially considering its multifactorial nature.

Potential for recovery after extremely prolonged VV-ECMO support in well-selected severe COVID-19 patients: a retrospective cohort study.

BACKGROUND: VenoVenous ExtraCorporeal Membrane Oxygenation (VV-ECMO) has been widely used as supportive therapy for severe respiratory failure related to Acute Respiratory Distress Syndrome (ARDS) due to coronavirus 2019 (COVID-19). Only a few data describe the maximum time under VV-ECMO during which pulmonary recovery remains possible. The main objective of this study is to describe the outcomes of prolonged VV-ECMO in patients with COVID-19-related ARDS. METHODS: This retrospective study was conducted at a tertiary ECMO center in Brussels, Belgium, between March 2020 and April 2022. All adult patients with ARDS due to COVID-19 who were managed with ECMO therapy for more than 50 days as a bridge to recovery were included. RESULTS: Fourteen patients met the inclusion criteria. The mean duration of VV-ECMO was 87 ± 29 days. Ten (71%) patients were discharged alive from the hospital. The 90-day survival was 86%, and the one-year survival was 71%. The evolution of the patients was characterized by very impaired pulmonary compliance that started to improve slowly and progressively on day 53 (± 25) after the start of ECMO. Of note, four patients improved substantially after a second course of steroids. CONCLUSIONS: There is potential for recovery in patients with very severe ARDS due to COVID-19 supported by VV-ECMO for up to 151 days.

Association of Plasma Myeloperoxidase with Inflammation and Diabetic status in HFpEF.

Background: Inflammation and oxidative stress are thought to play an important role in the pathophysiology of heart failure with preserved ejection fraction (HFpEF) through the development of endothelial dysfunction. Myeloperoxidase (MPO) functions as a link between oxidative stress and inflammation and is an interesting therapeutic target. The objective of this observational cohort study was to compare MPO levels between HFpEF and old controls, to define clinical characteristics associated with high levels of MPO and to assess the relation between MPO levels and vascular function. Methods: Patients with HFpEF (N = 55) and controls > 60 years (N = 18) were prospectively included. All subjects underwent complete echocardiography and blood sampling. MPO levels were dosed by ELISA assay. Effective arterial elastance (Ea) and peripheral arterial tonometry (EndoPAT reactive hyperemia index RHI and augmentation index AIx) were used to assess vascular function. Characteristics between groups defined by the median of MPO were compared using independent samples t-test or chi square test. Results: Patients with HFpEF (80 ± 8.7 years, 65% female) had higher levels of MPO compared to controls (75 ± 5.0 years, 72% female) (34.7 ng/mL [22.7; 44.0] vs 22.6 [18.2; 32.0], p = 0.026). MPO levels were correlated with markers of inflammation; C-reactive protein (Pearson's R = 0.46, p = 0.001) and neutrophile to lymphocyte ratio (R = 0.36, p = 0.031) and with signs of left ventricular (LV) remodelling and elevated filling pressures, namely NT-proBNP levels (R = 0.32, p = 0.019), decreased LV ejection fraction (LVEF, R = -0.36, p = 0.008) and E/e' ratio (R = 0.35, p = 0.011). HFpEF patients with levels of MPO above the median were more often men (48% vs 21%, p = 0.037) and suffered more often from diabetes (48% vs 18%, p = 0.017). Intriguingly, they had lower indices of vascular stiffness (augmentation index 11.1 [0.1; 30.7] vs 19.9 [10.5; 33.4], p = 0.018 and arterial elastance Ea 2.06 ± 0.676 vs 2.43 ± 0.721, p = 0.065) and there was no difference in endothelial function (1.82 [1.34; 2.30] vs 1.66 [1.32; 1.95], p = 0.55). Conclusions: HFpEF patients have higher levels of MPO than controls, reflecting leukocyte activation and oxidative stress. Among patients, high levels of MPO are associated with male sex, diabetic status, subtle left ventricular dysfunction and pronounced diastolic dysfunction. The association between oxidative stress and vascular stiffness, on the other hand could not be demonstrated. Clinical Trial Registration: Clinical trial NCT03197350.

Left Atrial Glucose Metabolism Evaluation by 18F-FDG-PET in Persistent Atrial Fibrillation and in Sinus Rhythm.

The role of atrial metabolism alterations for initiation and atrial fibrillation (AF) persistence remains poorly understood. Therefore, we evaluated left atrial glucose metabolism by nicotinic acid derivative stimulated 18-fluorodeoxyglucose positron emission tomography in 36 patients with persistent AF undergoing catheter ablation before and 3 months after return to sinus rhythm and compared values against healthy controls. Under identical hemodynamics and metabolic conditions, and although left ventricular FDG uptake remained unchanged, patients in persistent AF presented significantly higher total left atrial and left atrial appendage uptake, which decreased significantly after return to sinus rhythm, despite improvement of passive and active atrial contractile function. These findings support a role of altered glucose metabolism and metabolic wasting underlying the pathophysiology of persistent AF.

Cardiac structure, function, and coronary anatomy 10 years after isolated contemporary adjuvant radiotherapy in breast cancer patients with low cardiovascular baseline risk.

AIMS: The effects of isolated contemporary low-dose breast cancer (BC) radiotherapy (RT) on the heart remain poorly understood. This study aims to assess the long-term impacts of BC-RT on cardiac structure and function. METHODS AND RESULTS: Seventy-six women (62 ± 7 years) without history of prior heart disease, who had undergone RT for either first left (n = 36) or right (n = 40) BC, without additional medical oncology therapy apart from hormonal treatment 11 ± 1 years earlier, underwent transthoracic echocardiography, cardiac magnetic resonance imaging (CMR), computed tomography coronary angiography (CTCA), NT-proBNP, and a 6-min walk test (6MWT). They were compared with 54 age-matched healthy female controls. By CTCA, 68% of BC patients exhibited no or very mild coronary disease, while only 11% had moderate stenosis (50-69%) and 3% had significant stenosis (>70%). Despite slightly reduced regional echocardiographic midventricular strains, BC patients exhibited similar global left and right ventricular volumes, ejection fractions, and global strains by echocardiography and CMR as controls. Mitral E/e' ratios were slightly higher, and mitral deceleration times were slightly lower, but NT-proBNP was similar to controls. Also, 6MWT was normal. None had late gadolinium enhancement, and extracellular volume fraction was similar in BC (28 ± 3 vs. 29 ± 3, P = 0.15) and controls. No differences were observed relative to dose or side of RT. CONCLUSION: Aside from minor alterations of regional strains and diastolic parameters, women who received isolated RT for BC had low prevalence of coronary disease, normal global systolic function, NT-proBNP, and exercise capacity and showed no structural changes by CMR, refuting significant long-term cardiotoxicity in such low-risk patients.

Quantifying the Survival Loss Linked to Late Therapeutic Indication in High-Gradient Severe Aortic Stenosis.

Background: International guidelines recommend aortic valve replacement (AVR) as Class I triggers in high-gradient severe aortic stenosis (HGSAS) patients with symptoms and/or left ventricular ejection fraction (LVEF) <50%. The association between waiting for these triggers and postoperative survival penalty is poorly studied. Objectives: The purpose of this study was to examine the impact of guideline-based Class I triggers on long-term postoperative survival in HGSAS patients. Methods: 2,030 patients operated for HGSAS were included and classified as follows: no Class I triggers (no symptoms and LVEF >50%, n = 853), symptoms with LVEF >50% (n = 965), or LVEF <50% regardless of symptoms (n = 212). Survival was compared after matching (inverse probability weighting) for clinical differences. Restricted mean survival time was analyzed to quantify lifetime loss. Results: Ten-year survival was better without any Class I trigger than with symptoms or LVEF <50% (67.1% ± 3% vs 56.4% ± 3% vs 53.1% ± 7%, respectively, P < 0.001). Adjusted death risks increased significantly in operated patients with symptoms (HR: 1.45 [95% CI: 1.15-1.82]) or LVEF <50% (HR: 1.47 [95% CI: 1.05-2.06]) than in those without Class I triggers. Performing AVR with LVEF >60% produced similar outcomes to that of the general population, whereas operated patients with LVEF <60% was associated with a 10-year postoperative survival penalty. Furthermore, according to restricted mean survival time analyses, operating on symptomatic patients or with LVEF <60% led to 8.3- and 11.4-month survival losses, respectively, after 10 years, compared with operated asymptomatic patients with a LVEF >60%. Conclusions: Guideline-based Class I triggers for AVR in HGSAS have profound consequences on long-term postoperative survival, suggesting that HGSAS patients should undergo AVR before trigger onset. Operating on patients with LVEF <60% is already associated with a 10-year postoperative survival penalty questioning the need for an EF threshold recommending AVR in HGSAS patients.

Carbohydrate antigen 125: a useful marker of congestion, fibrosis, and prognosis in heart failure with preserved ejection fraction.

AIMS: Heart failure (HF) with preserved ejection fraction (HFpEF) is a disease associated with high morbidity and mortality, for which it is difficult to identify patients with the poorest prognosis in routine clinical practice. Carbohydrate antigen 125 (CA 125) has been shown to be a potential marker of congestion and prognosis in HF. We sought to better characterize HFpEF patients with high CA 125 levels by using a multimodal approach. METHODS AND RESULTS: We prospectively enrolled 139 HFpEF patients (78 ± 8 years; 60% females) and 25 controls matched for age and sex (77 ± 5 years; 60% females). They underwent two-dimensional echocardiography, cardiac magnetic resonance with late gadolinium enhancement [including extracellular volume (ECV) measurement], and serum measurements of CA 125 level. The primary endpoint of the study was a composite of all-cause mortality or first HF hospitalization. The prognostic impact of CA 125 was determined using Cox proportional hazard models. Median CA 125 levels were significantly higher in HFpEF patients compared with controls [CA 125: 23.5 (14.5-44.7) vs. 14.6 (10.3-21.0) U/mL, P = 0.004]. CA 125 levels were positively correlated with a congestion marker [N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, Pearson's r = 0.37, P < 0.001] and markers of cardiac fibrosis estimated by both ECV (Pearson's r = 0.26, P = 0.003) and fibroblast growth factor 23 levels (Pearson's r = 0.50, P < 0.001). Over a median follow-up of 49 (22-64) months, 97 HFpEF patients reached the composite endpoint. Even after adjustment for the Meta-Analysis Global Group in Chronic risk score, a CA 125 level ≥35 U/mL was still a significant predictor of the composite endpoint [hazard ratio (HR): 1.58 (1.04-2.41), P = 0.032] and more particularly of HF hospitalization [HR: 1.81 (1.13-2.92), P = 0.014]. In contrast, NT-proBNP levels were not an independent predictor. CONCLUSIONS: CA 125 levels were significantly higher in HFpEF patients compared with controls matched for age and sex and were associated with markers of congestion and cardiac fibrosis. CA 125 levels were a strong and independent predictor of HF hospitalization in HFpEF patients. These data suggest a potential value of CA 125 as a biomarker for staging and risk prediction in HFpEF.

Plasma myo-inositol elevation in heart failure: clinical implications and prognostic significance. Results from the BElgian and CAnadian MEtabolomics in HFpEF (BECAME-HF) research project.

BACKGROUND: The metabolic environment plays a crucial role in the development of heart failure (HF). Our prior research demonstrated that myo-inositol, a metabolite transported by the sodium-myo-inositol co-transporter 1 (SMIT-1), can induce oxidative stress and may be detrimental to heart function. However, plasmatic myo-inositol concentration has not been comprehensively assessed in large cohorts of patients with heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). METHODS: Plasmatic myo-inositol levels were measured using mass spectrometry and correlated with clinical characteristics in no HF subjects and patients with HFrEF and HFpEF from Belgian (male, no HF, 53%; HFrEF, 84% and HFpEF, 40%) and Canadian cohorts (male, no HF, 51%; HFrEF, 92% and HFpEF, 62%). FINDINGS: Myo-inositol levels were significantly elevated in patients with HF, with a more pronounced increase observed in the HFpEF population of both cohorts. After adjusting for age, sex, body mass index, hypertension, diabetes, and atrial fibrillation, we observed that both HFpEF status and impaired kidney function were associated with elevated plasma myo-inositol. Unlike HFrEF, abnormally high myo-inositol (≥69.8 µM) was linked to unfavourable clinical outcomes (hazard ratio, 1.62; 95% confidence interval, [1.05-2.5]) in patients with HFpEF. These elevated levels were correlated with NTproBNP, troponin, and cardiac fibrosis in this subset of patients. INTERPRETATION: Myo-inositol is a metabolite elevated in patients with HF and strongly correlated to kidney failure. In patients with HFpEF, high myo-inositol levels predict poor clinical outcomes and are linked to markers of cardiac adverse remodelling. This suggests that myo-inositol and its transporter SMIT1 may have a role in the pathophysiology of HFpEF. FUNDING: BECAME-HF was supported by Collaborative Bilateral Research Program Québec - Wallonie-Brussels Federation.

Prognostic Implications of Discordant Low-Gradient Severe Aortic Stenosis: Comprehensive Analysis of a Large Multicenter Registry.

Background: Up to 30% of patients with severe aortic stenosis (SAS) (indexed aortic valve area [AVAi] <0.6 cm2/m2) exhibit low-transvalvular gradient despite normal ejection fraction. There is intense debate regarding the prognostic significance of this entity. Objectives: The purpose of this study was to compare the outcome of patients with discordant low-gradient SAS (DLG-SAS) vs moderate aortic stenosis (MAS) and high-gradient SAS (HG-SAS). Methods: We used the BEL-F-ASt (Belgium-France-Aortic Stenosis) registry including consecutive patients with AS. Survival was compared overall and after matching (inverse probability weighting and propensity-score matching) for clinical and imaging variables. The analysis was first performed in the overall population (n = 2,582) and then in the population of unoperated patients (n = 1,812). Results: After-inverse probability weighting-matching, the 3 groups were balanced. Five-year survival was better in MAS than in DLG-SAS and HG-SAS-patients (58.9% vs 47% vs 41.2%, P < 0.001). Similar results were obtained in unoperated patients (54.1% vs 37.9% vs 28.1%, P < 0.001). To explore the impact of MG (≤40 vs >40 mmHg) and AVAi (<0.6 vs ≥0.6 cm2/m2) on outcomes, survival of propensity score-matched cohorts of HG-vs DLG-SAS and MAS vs DLG-SAS were compared. After matching for MG, survival was better in MAS than in DLG-SAS (52% vs 40%, P < 0.001). After matching for AVAi, survival was better in DLG-SAS than in HG-SAS patients (45% vs 33%, P < 0.001). Conclusions: Survival of DLG-SAS is better than that of HG-SAS and worse than that of MAS patients. At comparable MG, the lower the AVAi, the worse the prognosis, whereas at comparable AVAi, the higher the MG, the worse the prognosis. These data argue that DLG-SAS is an intermediate form in the disease continuum.