COVID-19 is associated with long-term vascular complications, but the underlying mechanisms remain incompletely understood. During infection, NAD+ homeostasis becomes dys-regulated, with excessive NAD+ consumption and enhanced catabolic flux through nicotinamide methylation pathways. This imbalance leads to NAD+ depletion accompanied by accumulation of pyridone metabolites, including N-methyl-2-pyridone-5-carboxamide (Met2PY) and N-methyl-4-pyridone-3-carboxamide (Met4PY). These derivatives have been linked to oxidative stress, endothelial dysfunction, and cardiovascular risk, yet their role in long COVID remains unclear. We enrolled 26 post-COVID patients with persistent cardiovascular symptoms and 8 healthy controls. Serum concentrations of Met2PY and Met4PY were quantified by LC/MS. High-sensitivity C-reactive protein (hsCRP), tumor necrosis factor-alpha (TNFα), interleukin-10 (IL-10), and soluble intercellular adhesion molecule-1 (sICAM-1) were measured to assess systemic inflammation and endothelial activation. Statistical analyses included group comparisons and correlation analyses. We observed significantly elevated Met2PY levels (0.770 ± 0.08 vs. 0.389 ± 0.09 µmol/l) and a trend toward increased Met4PY (0.095 ± 0.01 vs. 0.055 ± 0.01 µmol/l) in post-COVID patients compared with controls. Both metabolites positively correlated with hsCRP. Importantly, Met2PY was associated with an unfavorable cytokine profile (higher TNFα/IL-10 ratio) and increased sICAM-1 levels, whereas no such associations were observed for Met4PY. Persistent dysregulation of NAD+ metabolism and accumulation of pyridone metabolites, particularly Met2PY, are associated with markers of chronic endothelial activation and inflammation in long COVID. These findings support the potential utility of Met2PY as a biomarker to identify patients at higher risk for endothelial dysfunction and cardiovascular events, enabling more personalized risk stratification and follow-up.

Autoimmune rheumatic diseases (ARDs) are characterized by excessive immune system dysregulation and a significant inflammatory milieu that provokes multiorgan damage. Inflammation holds a key role in the pathophysiology of cardiovascular disease (CVD), thereby explaining the increased cardiovascular risk of patients with ARDs. Among all cardiovascular risk factors, hypertension is the most prevalent one in patients with ARDs. The pathogenesis of hypertension in ARDs is multifactorial and the result of a complex interplay between several traditional cardiovascular risk factors, the sympathetic nervous system, autoimmune disease specific factors and genetic predisposition. Importantly, even though patients with ARDs and hypertension suffer a markedly increased cardiovascular risk, current guidelines lack a widely accepted risk prediction tool to accurately estimate CVD risk and provide a highly individualized approach. This review aims to analyse the prevalence and pathophysiology of hypertension in patients with ARDs and provide an overview of cardiovascular risk assessment in this high-risk group.

The aim of this research is to develop a bioactive coating with potential applications in vascular stents. For this purpose, the use of natural materials such as chitosan in combination with the nucleoside adenosine has been proposed, which protects against endothelial dysfunction, vasculitis, or thrombosis. The coatings were produced through the electrophoretic deposition method (EDP). Surface characterization was performed using microscopic methods and a drop shape analyzer. Mechanical, corrosion and degradation tests were carried out, and the release profile was analyzed over 3 days. Additionally, platelet adhesion and the effect of the modification on cellular response were evaluated. Adenosine release was confirmed for up to 72 h in biologically significant concentrations. The addition of adenosine increased the contact angle and improved corrosion resistance compared to unmodified coatings. An increase in the coating's stiffness and Young's modulus was also observed. Hardness increased only at the highest adenosine concentration applied. Chitosan modification reduced platelet adhesion to the material surface. Endothelial cell (EC) adhesion and slight proliferation were demonstrated. XTT studies have shown that increasing the concentration of exogenous adenosine above 50 & micro;M improves the survival of fibroblasts. In the case of endothelial cells, no cytotoxic effect is observed regardless of the concentration used. Studies have shown that the chitosan-adenosine composite coating has potential for use in vascular stents.

The vascular endothelium performs numerous regulatory functions that impact inflammatory responses, thrombosis, vascular tone and angiogenesis. Endothelial dysfunction is a key contributor to the pathogenesis of various human diseases, either as a primary trigger or as a consequence of organ damage.This review examines how ageing reshapes endothelial cell metabolism and mitochondrial function, progressively undermining endothelial homeostasis and resilience. Age-related endothelial alterations, including reduced nitric oxide bioavailability, heightened oxidative stress, impaired vasodilatory capacity and pro-inflammatory activation, arise from coordinated shifts in energy production, substrate utilization and redox signaling. In this context, cellular senescence, a stable arrest of the cell cycle accompanied by distinct metabolic, secretory and inflammatory changes, appears to be an important response to cumulative metabolic and mitochondrial stress. Senescent endothelial cells not only reflect this stress burden but also actively propagate dysfunction through sustained pro-inflammatory and pro-oxidant signalling, thereby accelerating vascular ageing. We highlight the central role of mitochondria in these events. Age-associated mitochondrial dysfunction disrupts bioenergetics, enhances reactive oxygen species generation and fuels chronic low-grade inflammation, amplifying endothelial decline.By bringing together current evidence-based knowledge on endothelial cell bioenergetics, mitochondrial impairment and metabolic reprogramming, this review identifies mitochondria-driven metabolic deterioration as a key mechanism underlying endothelial ageing and underscores mitochondrial metabolism as a promising, yet underexploited, therapeutic target in age-related vascular dysfunction.

Mitochondrial dysfunction plays a critical role in the pathogenesis of cardiovascular and metabolic diseases. However, direct assessment of mitochondrial respiration in human vascular tissue remains technically challenging. In this study, we present an ex vivo approach for real-time analysis of mitochondrial respiration in human left internal mammary artery (LIMA) grafts obtained during coronary artery bypass grafting (CABG). LIMA segment was collected intraoperatively and processed for bioenergetic assessment using the Seahorse XF Flex 3D Analyzer. Mitochondrial respiration was evaluated using the Mito Stress Test, enabling real-time measurement of oxygen consumption rate (OCR). In parallel, tissue nucleotide levels were quantified using high-performance liquid chromatography (HPLC), allowing complementary assessment of cellular energy status and redox balance. We demonstrate the feasibility of measuring mitochondrial respiration in intact human arterial tissue ex vivo. To our knowledge, this is the first application of the Seahorse XF Flex 3D platform for real-time bioenergetic analysis in intact human vascular tissue. Combined analysis of OCR and nucleotide levels enabled integrated assessment of vascular bioenergetic status. The applied protocol enabled reliable assessment of key bioenergetic parameters, including basal and maximal respiration. This study establishes a novel proof-of-concept workflow for ex vivo bioenergetic profiling of human vascular grafts, providing a platform for future investigations of vascular metabolism in cardiovascular and metabolic disorders.

Clinical management of hypertension in patients with autoimmune rheumatic diseases (ARDs) is challenging. Firstly, the impact on blood pressure (BP) of several antirheumatic drugs varies and the available evidence points towards a wide range of effects. Secondly, management of hypertension in terms of diagnosis, BP thresholds and therapeutic targets currently follows the general recommendations, even though patients with ARDs present a markedly adverse cardiovascular profile. Thirdly, lifestyle interventions in terms of non-pharmaceutical management follow the general recommendations. Notably, it has been shown that they can improve autoimmune disease-specific endpoints, however, their intimate effect on BP has not been fully explored. Finally, the choice of anti-hypertensive medication currently complies with the general antihypertensive therapy recommendations, in the absence of appropriately designed studies in these populations. This review aims to summarize the impact of antirheumatic drugs on BP and present the available data regarding clinical management of hypertension in patients with ARDs.

OBJECTIVE:Endothelial and microvascular dysfunction are key features of Long COVID. Disturbances in cellular redox balance, reflected by altered nicotinamide adenine dinucleotide (NAD+/NADH) dynamics, may underlie vascular impairment. Flow-Mediated Skin Fluorescence (FMSF) evaluates microvascular function by monitoring NADH fluorescence during ischemia and reperfusion. We integrated FMSF-derived microvascular phenotyping with targeted NAD+ metabolite profiling to determine whether altered NAD+ metabolism is associated with impaired microvascular responses in Long COVID. METHODS:Microvascular function was assessed in 36 patients with Long COVID and 47 age-matched controls using FMSF. NADH fluorescence changes during ischemia and hyperemia were analyzed as markers of endothelial responsiveness. NAD+ and related metabolites were measured using high-performance liquid chromatography and mass spectrometry. RESULTS:Patients with Long COVID showed impaired FMSF parameters, including blunted ischemic responses and delayed recovery after hyperemia, indicating microvascular dysfunction. These changes were accompanied by a reduced NAD+/NADH ratio and lower NADP levels, consistent with redox imbalance. Abnormal fluorescence profiles were associated with altered NAD+ metabolism, including reduced precursor availability and accumulation of degradation products. Higher NR concentrations showed associations with selected microvascular and eNOS-related parameters. CONCLUSIONS:FMSF provides a clinically applicable tool for detecting microvascular dysfunction in Long COVID. NAD+ redox imbalance is linked to impaired microcirculatory responses, supporting FMSF as a functional marker of microvascular impairment associated with altered NAD+ metabolism.

BACKGROUND/AIMS:Flozins (sodium-glucose cotransporter 2 inhibitors, SGLT2i) are a new class of antidiabetic drugs that reduce cardiovascular mortality and hospitalization rates in heart failure, regardless of type 2 diabetes status. Besides lowering glycemia by inhibiting renal glucose reabsorption, SGLT2 inhibitors may exert sodium-dependent hemodynamic effects and improve cardiomyocyte energy metabolism, substrate preference, and mitochondrial function. However, their impact on endothelial cells remains largely unknown. This study aimed to analyse the effects and mechanisms of SGLT2i on endothelial cell metabolism and function. METHODS:Mouse cardiac endothelial cells (H5V) were used to test the impact of dapagliflozin on endothelial cell metabolism and function in the presence of hypoxia-mimicking conditions. The concentration of intracellular nucleotides was measured using high-performance liquid chromatography. Mitochondrial and glycolytic activity were assessed using Seahorse XFp, while nitric oxide (NO) production was determined by 4-Amino-5-Methylamino-2',7'-Difluorofluorescein (DAF-FM) fluorescence staining. The effects of dapagliflozin treatment on endothelial NO synthesis were also analysed in patients with chronic heart failure and left ventricular ejection fraction above 40% and C57Bl/6J mice. RESULTS:Dapagliflozin augmented adenosine triphosphate (ATP) levels and the ATP/ADP (adenosine diphosphate) ratio in cultured endothelial cells correlated to increased NO production. Dapagliflozin-treated endothelial cells produced ATP through both mitochondrial respiration and glycolysis. Interestingly, mitochondrial respiration was enhanced, while glycolysis was unaffected in endothelial cells after in vitro dapagliflozin treatment. In a murine model, dapagliflozin doubled the rate of coronary NO synthesis and tended to improve coronary capillary density. In humans with chronic heart failure, 3-month treatment with dapagliflozin revealed many metabolic effects, suggesting potential mechanisms related to nitric oxide homeostasis, mitochondrial function, and L-arginine metabolism. CONCLUSION:This study demonstrated the beneficial effect of dapagliflozin on endothelial cell metabolism and function. Regulation of endothelial cell bioenergetics may be an undervalued mechanism of SGLT2i to delay heart failure progression and support cardiac regeneration. These may accelerate endothelial-targeted strategies to support heart failure treatment.

Introduction:Atopic dermatitis (AD) is a chronic, inflammatory skin disease with severe itching. Particular attention is dedicated to the coexistence of AD with diseases of the cardiovascular system. Since the earliest manifestation of cardiovascular disease is microvascular endothelium dysfunction, an attempt was made to assess the skin microcirculation. Aim:The work aims to analyse the assessment of skin microcirculation in patients with atopic dermatitis based on changes of nicotinamide adenine dinucleotide (NADH) fluorescence from the epidermis of the forearm measured with the flow mediated skin fluorescence (FMSF) technique. Material and methods:Thirteen patients with AD and eleven healthy individuals participated in the study. Changes in NADH fluorescence were measured by the FMSF technique on the forearm in response to blockage and release of blood flow. Results are presented as a maximum ischemic response (IRmax and IRindex,), hyperaemic response (HRmax and HRindex) or hypoxia sensitivity (HS). Results:The analysed FMSF parameters: IRmax, IRindex, HRmax and HRindex, HS were not significantly lower in AD patients compared with the control group. There was no association between disease severity and NADH fluorescence. Conclusions:The association of AD with cardiovascular disease is multifactorial. The basis of these connections is still being investigated. Microvascular endothelial dysfunction may be one but not the only mechanism responsible for the increased cardiovascular risk in patients with AD.

Gliflozins, also known as sodium-glucose cotransporter 2 inhibitors (SGLT2i), constitute a new class of antidiabetic drugs shown to reduce cardiovascular mortality and decrease hospitalisation frequency in patients with heart failure (HF), regardless of coexisting type 2 diabetes. In addition to lowering blood glucose levels by inhibiting renal glucose reabsorption, SGLT2i also affects sodium transport and improves cardiomyocyte mitochondrial function and energy metabolism. The influence of gliflozins on the metabolism and function of endothelial cells is not well understood. Endothelial dysfunction, which occurs in the single layer of cells lining the blood vessels, often precedes damage to heart muscle cells during HF. This dysfunction can manifest in two ways: 1) obstructive atherosclerosis in the coronary arteries due to subendothelial inflammation and lipid plaque deposition and 2) microvascular dysfunction stemming from structural and functional changes in smaller blood vessels. Both factors contribute to the progression of HF and reduce the amount of oxygen supplied to the myocardium. This review aimed to explore the latest findings from preclinical and clinical studies regarding the effects of gliflozins on endothelial cell function, mitochondrial activity and energy metabolism. Targeting endothelial injury may prove beneficial in preventing and treating both macro- and microcirculatory dysfunction, delaying heart failure progression and supporting cardiac regeneration. DATA AVAILABILITY: Data will be made available on request.

Long COVID is a complex pathophysiological condition. However, accumulating data suggests that COVID-19 is a systemic microvascular endothelial dysfunction with different clinical manifestations. In this study, a microvascular function was assessed in long COVID patients (n = 33) and healthy controls (n = 30) using flow-mediated skin fluorescence technique (FMSF), based on measurements of nicotinamide adenine dinucleotide fluorescence intensity during brachial artery occlusion (ischemic response, IR) and immediately after occlusion (hyperemic response, HR). Microcirculatory function readings were taken twice, 3 months apart. In addition, we quantified biochemical markers such as the serum L-arginine derivatives and hypoxia-inducible factor 1 alpha (HIF1 alpha) to assess their relation with microvascular parameters evaluated in vivo. In patients with long COVID, serum HIF1 alpha was significantly correlated to IRindex (r = -0.375, p < 0.05). Similarly, there was a significant inverse correlation of serum asymmetric dimethyl-L-arginine levels to both HRmax (r = -0.343, p < 0.05) and HRindex (r = -0.335, p < 0.05). The IR parameters were found lower or negative in long COVID patients and recovered in three-month follow-up. Hypoxia sensitivity value was significantly higher in long COVID patients examined after three months of treatment based on the combination of ACE-inhibitors and beta-adrenolytic compared to baseline condition (85.2 +/- 73.8 vs. 39.9 +/- 51.7 respectively, p = 0.009). This study provides evidence that FMSF is a sensitive, non-invasive technique to track changes in microvascular function that was impaired in long COVID and recovered after 3 months, especially in patients receiving a cardioprotective therapy.

Background: Cardiac involvement (CI) in systemic sclerosis (SSc) is frequently subclinical and it can be identified in up to 80% of autopsied hearts. If present, symptoms are related to adverse prognosis, and CI represents one of the predominant causes of SSc-related mortality. Methods: A total of 20 patients with a diagnosis of SSc were included and followed up, and 37 volunteers were included and subsequently scanned on a 1.5T MR system. Results: Overall, thirteen (65%) patients had one or more abnormal cardiac findings in CMR (defined as CI[+]), of which in seven (35%), baseline ECGs and standard echocardiograms were normal or unspecific. Compared to healthy volunteers, SSc patients had a lower LVEF% (56.6% vs. 61.6%; p = 0.0131), longer T1 (1028.3 ms vs. 993.1 ms; p = 0.0049) and T2 relaxation times (48.24 ms vs. 43 ms p = 0.0011), and higher extracellular volume (ECV, 27.9% vs. 26.0%; p = 0.0112). However, no difference in CMR-derived, feature-tracking GLS values between patients and healthy controls was found (−15.5[2,8] vs. −16.3[1,1], respectively, p = 0.11). Over 3.4 (1.9–5.5) years, three patients (15%) died, and two others (10%) sustained major cardiac complications. Conclusions: Cardiac magnetic resonance with modern quantitative techniques reveals subtle morpho-functional alterations and thus allows for early diagnosis of myocardial involvement in systemic sclerosis. Our findings emphasize the need for extended diagnostic workup in these patients and demonstrate the ability of cardiac MR to select patients requiring closer follow-up and/or treatment decisions.