Emerging therapies for refractory hypercholesterolemia: a narrative review.

Refractory hypercholesterolemia (RH) is characterized by the failure of patients to achieve therapeutic targets for low-density lipoprotein-cholesterol (LDL-C) despite receiving maximal tolerable doses of standard lipid-lowering treatments. It predominantly impacts individuals with familial hypercholesterolemia (FH), thereby elevating the risk of cardiovascular complications. The prevalence of RH is now recognized to be substantially greater than previously thought. This review provides a comprehensive insight into current and emerging therapies for RH patients, including groundbreaking genetic-based therapeutic approaches. The review places emphasis on the dependency of therapies on low-density lipoprotein receptors (LDLRs) and highlights the critical role of considering LDLR activity in RH patients for individualization of the treatment.

Refractory hypercholesterolemia (RH) is a condition where patients are unable to get below target levels of 'bad' cholesterol despite receiving maximum doses of standard treatments. It is commonly present in those with a genetic disorder, called familial hypercholesterolemia (FH), known to increase the risk of heart complications. RH's prevalence is now understood to be higher than previously believed and this review offers insights into current and emerging therapies for RH, including genetic-based treatments. It stresses the importance of the mechanistic pathways behind cholesterol clearance, particularly low-density lipoprotein receptor (LDLR) activity, in RH treatment customization.

OxLDL as a prognostic biomarker of plaque instability in patients qualified for carotid endarterectomy.

Atherosclerotic plaque instability increases the risk of stroke. As such, determining the nature of an instability atherosclerotic plaque may speed up qualification for carotid endarterectomy (CEA), thus reducing the risk of acute vascular events. The aim of the study was to determine the diagnostic value of oxidized LDL cholesterol (ox-LDL), matrix metalloproteinase 9 (MMP-9) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in serum as a prognostic markers of instability atherosclerotic plaques. Serum was collected from 67 patients who underwent CEA in accordance with the qualification criteria. The levels of ox-LDL, MMP-9 and 8-OHdG were assessed by ELISA. The predictive value of the markers was determined based on an ROC curve, and the cut-off points with the highest sensitivity and specificity were determined. Patients with unstable atherosclerotic plaque had significantly higher serum ox-LDL, MMP-9 and 8-OHdG values. It was found that in patients before CEA, ox-LDL >31.4 ng/mL was associated with an 82.5% probability of unstable atherosclerotic plaque, MMP-9 >113.1 ng/mL with 78.6%, and 8-OHdG >2.15 ng/mL with 64.7%. Multivariate regression analysis found ox-LDL to be an independent factor associated with plaque instability. Patients with unstable plaques tend to have higher serum levels of ox-LDL, MMP-9 and 8-OHdG compared to those with stable plaques. The optimal cut-off point for ox-LDL (AUC 0.86, p <0.0001) was 31.14 ng/mL, with 91.18% sensitivity and 78.79% specificity. The high sensitivity and specificity of ox-LDL suggests that it can be used as an independent marker of plaque instability.

Lipoprotein(a) is associated with DNA damage in patients with heterozygous familial hypercholesterolemia.

Heterozygous familial hypercholesterolemia (HeFH) is a common autosomal-dominant inherited disorder associated with atherosclerotic cardiovascular disease (ASCVD). HeFH subjects have a higher lipoprotein(a), i.e. Lp(a), concentration than the general population. Patients with FH are exposed to elevated levels of LDL from birth and ox-LDL may induce other oxidation pathways. The aim of the study was to determine the levels of markers of oxidative stress and DNA damage in patients with HeFH and describe the effect of Lp(a) on the resulting damage. Higher DNA damage was identified in patients with HeFH compared to the normolipidemic ones, and ASCVD was associated with greater damage. Oxidative stress markers were elevated in HeFH patients; however, only ox-LDL was higher in the ASCVD group and its level correlated with DNA damage. A positive correlation was found between DNA damage and Lp(a) concentration in the HeFH patients. Higher levels of Lp(a) were associated with greater DNA damage, especially in patients with HeFH and ASCVD. In HeFH patients, the optimal Lp(a) cut-off point associated with ASCVD is > 23.45 nmol/L, i.e. much lower than for the general population; however this cut-off point needs validation in a larger group of HeFH patients.

When the same treatment has different response: The role of pharmacogenomics in statin therapy.

Statins, also known as HMG-CoA reductase inhibitors, are one of the most potently prescribed and thoroughly researched medications, predominantly utilized for managing cardiovascular diseases by modulating serum cholesterol levels. Despite the well-documented efficacy of statins in reducing overall mortality via attenuating the risk of cardiovascular diseases, notable interindividual variability in therapeutic responses persists as such variability could compromise the lipid-lowering efficacy of the drug, potentially increasing susceptibility to adverse effects or attenuating therapeutic outcomes.This phenomenon has catalysed a growing interest in the scientific community to explore common genetic polymorphisms within genes that encode for pivotal enzymes within the pharmacokinetic pathways of statins. In our review, we focus to provide insight into potentially clinically relevant polymorphisms associated with statins' pharmacokinetic participants and assess their consequent implications on modulating the therapeutic outcomes of statins among distinct genetic carrier.

Severe COVID-19 classified by simple covid risk index is associated with higher levels of advanced oxidation protein products and 8-hydroxy 2 deoxyguanosine.

SARS-CoV-2 has become one of the most important and challenging medical research topics in recent years. The presence of endothelial dysfunction, immune thrombosis, and oxidative stress contributes to complications and requires more extended hospitalisation of patients. In this article, we focused on analysing the impact of oxidative stress on the severity of COVID-19 infection. The study group consisted of 72 patients with laboratory-confirmed SARS-CoV enrolled. The patients were divided into moderate and severe diseases according to the SCRI (Simple Covid Risk Index, including lymphocyte/D-dimer ratio). Using the ELISA kit, we determined the level of AOPP and 8-OHdG. Patients with severe COVID-19 had higher levels of both AOPP (P < 0.05) and 8-OHdG (P < 0.05) compared to patients with moderate disease. Albumin levels were significantly lower (P < 0.001), although fibrinogen (P < 0.01), D-dimer (P < 0.001), and TF (P < 0.05) levels were higher in severe patients than in moderate course. AOPP/Alb was also higher among severe patients (P < 0.05). Our data suggest a potential role for AOPP and 8-OHdG in predicting the outcome of SARS-CoV-2 patients. Elevated AOPP levels were associated with increased Dimer-D, TF, and vWF activity levels.

SGLT2 Inhibitors May Restore Endothelial Barrier Interrupted by 25-Hydroxycholesterol.

SGLT2 (Sodium-glucose Cotransporter-2) inhibitors are newer glucose-lowering drugs with many cardiovascular benefits that are not fully understood yet. Endothelial integrity plays a key role in cardiovascular homeostasis. 25-hydroxycholesterol (25-OHC), which is a proatherogenic stimuli that impairs endothelial barrier functions. VE-cadherin is an endothelial-specific protein crucial in maintaining endothelial integrity. The aim of this study was to assess the influence of SGLT2i on the integrity of endothelial cells interrupted by 25-OHC. We also aimed to evaluate whether this effect is associated with changes in the levels of VE-cadherin. We pre-incubated HUVECs with 10 µg/mL of 25-hydroxycholesterol (25-OHC) for 4 h and then removed it and incubated endothelial cells with 1 µM of empagliflozin, 1 µM canagliflozin, or 1 µM dapagliflozin for 24 h. The control group included HUVECs cultured with the medium or with 25-OHC 10 µg/mL. The integrity of endothelial cells was measured by the RTCA-DP xCELLigence system, and VE-cadherin was assessed in confocal microscopy. Our results show that SGLT2 inhibitors significantly increase endothelial integrity in comparison to medium controls, and they improve endothelial cell integrity interrupted by 25-OHC. This effect is associated with significant improvements in VE-cadherin levels. SGLT2i: empagliflozin, canagliflozin, and dapagliflozin have a beneficial effect on the endothelial cell integrity and VE-cadherin levels reduced by 25-OHC.

Elevated Lp(a) and course of COVID-19: Is there a relationship?

BACKGROUND: Lipoprotein (a)-Lp(a) has proinflammatory, prothrombotic and proatherogenic properties and may theoretically influence the course of COVID-19. OBJECTIVES: The aim of the study was to explore whether patients hospitalized due to COVID-19 with Lp(a) ≥30mg/dl may develop a worse course of the disease, increased incidence of thromboembolic complications, intubation and ICU hospitalization or death. PATIENTS AND METHODS: A retrospective analysis was performed of 124 patients hospitalized due to COVID-19 in the Department of Internal Diseases and Clinical Pharmacology between 29 November 2020 and 15 April 2021. The only exclusion criterion was age≥80 years. Patients were divided into two groups: 1. COVID-19 patients with Lp(a) <30mg/dl regarded as not elevated n = 80; 2. COVID-19 patients with Lp(a) ≥30 regarded as elevated n = 44. RESULTS: A total of 124 COVID-19 patients were included in the study (66 men and 58 women) with a mean age of 62.8±11 years. COVID-19 patients with elevated Lp(a) level had significantly longer hospitalization time (11 vs. 9.5 days; p = 0.0362), more extensive radiological changes in CT scan (35 vs. 30%; p = 0.0301) and higher oxygen demand on admission (8 vs. 5L/min; p = 0.0428). Elevated Lp(a) was also associated with significantly higher OR for High Flow Nasal Oxygen Therapy (HFNOT) OR = 3.5 95%CI(1.2;8.9), p = 0.0140, Intubation and ICU OR = 4.1 95%CI(1.1;15.2) p = 0.0423, Death OR = 2.8 95%CI(0.9;8.5), p = 0.0409. CONCLUSIONS: Elevated Lp(a) might be one of the factors which contribute to a more severe course of COVID-19; however, further studies including larger groups of patients are needed.

Expression of anti and pro-inflammatory genes in human endothelial cells activated by 25-hydroxycholesterol: A comparison of rivaroxaban and dabigatran.

Atherosclerosis is associated with a haemostatic imbalance characterized by excessive activation of pro-inflammatory and pro-coagulant pathways. Non-vitamin K antagonists oral anticoagulant (NOACs) may reduce the incidence of cardiovascular events, cerebral ischemia, thromboembolic events and atherosclerosis. Chronic inflammation, vascular proliferation and the development of atherosclerosis is also influenced by 25-hydroxycholesterol (25-OHC). The aim of the study was to assess the effect of rivaroxaban and dabigatran on the messenger RNA (mRNA) expression of anti-inflammatory cytokines transforming growth factor ß (TGF-ß), interleukin (IL)-37, IL-35 as well as of pro-inflammatory cytokines IL-18 and IL-23, in endothelial cells damaged by 25-OHC. Human umbilical vascular endothelial cells (HUVECs) were treated with 25-OHC (10 µg/mL), rivaroxaban (100, 500 ng/mL), dabigatran (100, 500 ng/mL), 25-OHC + rivaroxaban, and 25-OHC + dabigatran. The mRNA expression of TGF-ß, IL-37, IL-35 subunits EBI3 and p35, IL-18, and IL-23 was analysed using real-time polymerase chain reaction (PCR). The results showed that 25-OHC decreased TGF-ß and IL-37 mRNA expression and increased EBI3, p35, IL-18, IL-23 mRNA expression in endothelial cell as compared to an untreated control (P < .05). Messenger RNA expression of TGF-ß and IL-37 significantly increased following stimulation with rivaroxaban and dabigatran as compared to an untreated control (P < .01). In HUVECs pre-treated with oxysterol, rivaroxaban and dabigatran increased mRNA expression of TGF-ß, IL-37 and decreased mRNA expression of EBI3, p35, IL-23 and IL-18 as compared to 25-OHC (P < .01). Our finding suggests that both rivaroxaban and dabigatran inhibit the inflammatory activation caused by oxysterol in vitro.

Dabigatran: its protective effect against endothelial cell damage by oxysterol.

Recent data showed that dabigatran can reduce not only procoagulatory effects but also block proinflammatory stimuli by inhibiting the expression of cytokines and chemokines and reducing thrombin-induced endothelial permeability. The aim of our study was to assess the effect of dabigatran on the integrity and inflammatory properties of endothelial cells stimulated by 25-hydroxycholesterol (25-OHC, oxysterol). HUVECs (Human Umbilical Vein Endothelial Cells) were stimulated with 25-hydroxycholesterol 10 µg/ml, dabigatran 100 ng/ml or 500 ng/ml and 25-hydroxycholesterol + dabigatran (100 ng/ml, 500 ng/ml). HUVEC integrity and permeability was measured in the RTCA-DP xCELLigence system and by the paracellular flux system. The mRNA expression of ICAM-1, VEGF, IL-33, MCP-1 and TNF-α was analyzed by Real-time PCR. Cell apoptosis and viability was measured by flow cytometry. VEGF protein concentration was assessed in supernatants by ELISA. VE-cadherin expression in endothelial cells was evaluated by confocal microscopy. Pre-stimulation of HUVECs with 25-OHC decreased endothelial cell integrity (p < 0.001) and increased the expression of IL-33, ICAM-1, MCP-1, VEGF, TNF-α mRNA (p < 0.01) compared to unstimulated controls. Following stimulation of HUVECs with dabigatran 100 ng/ml or 500 ng/ml restored HUVEC integrity interrupted by 25-OHC (p < 0.001). In HUVECs pre-stimulated with oxysterol, dabigatran stimulation decreased mRNA expression of the proinflammatory cytokines IL-33 and TNF-α, chemokines MCP-1 ICAM-1 and VEGF (p < 0.01). Dabigatran 500 mg/ml+ 25-OHC increased the endothelial expression of VE-cadherin as compared to 25-OHC (p < 0.01). Our findings suggest that dabigatran stabilizes the endothelial barrier and inhibits the inflammation caused by oxysterol.

Neuroprotective Effect of SGLT2 Inhibitors.

Patients with diabetes are at higher risk of cardiovascular diseases and cognitive impairment. SGLT2 inhibitors (Empagliflozin, Canagliflozin, Dapagliflozin, Ertugliflozin, Sotagliflozin) are newer hypoglycemic agents with many pleiotropic effects. In this review, we discuss their neuroprotective potential. SGLT2 inhibitors (SGLT2i) are lipid-soluble and reach the brain/serum ratio from 0.3 to 0.5. SGLT receptors are present in the central nervous system (CNS). Flozins are not fully SGLT2-selective and have an affinity for the SGLT1 receptor, which is associated with protection against ischemia/reperfusion brain damage. SGLT2i show an anti-inflammatory and anti-atherosclerotic effect, including reduction of proinflammatory cytokines, M2 macrophage polarization, JAK2/STAT1 and NLRP3 inflammasome inhibition, as well as cIMT regression. They also mitigate oxidative stress. SGLT2i improve endothelial function, prevent remodeling and exert a protective effect on the neurovascular unit, blood-brain barrier, pericytes, astrocytes, microglia, and oligodendrocytes. Flozins are also able to inhibit AChE, which contributes to cognitive improvement. Empagliflozin significantly increases the level of cerebral BDNF, which modulates neurotransmission and ensures growth, survival, and plasticity of neurons. Moreover, they may be able to restore the circadian rhythm of mTOR activation, which is quite a novel finding in the field of research on metabolic diseases and cognitive impairment. SGLT2i have a great potential to protect against atherosclerosis and cognitive impairment in patients with type 2 diabetes mellitus.

COVID-19: Direct and Indirect Mechanisms of Statins.

The virus responsible for the current COVID-19 pandemic is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): a new virus with high infectivity and moderate mortality. The major clinical manifestation of COVID-19 is interstitial pneumonia, which may progress to acute respiratory distress syndrome (ARDS). However, the disease causes a potent systemic hyperin-flammatory response, i.e., a cytokine storm or macrophage activation syndrome (MAS), which is associated with thrombotic complications. The complexity of the disease requires appropriate intensive treatment. One of promising treatment is statin administration, these being 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors that exert pleiotropic anti-inflammatory effects. Recent studies indicate that statin therapy is associated with decreased mortality in COVID-19, which may be caused by direct and indirect mechanisms. According to literature data, statins can limit SARS-CoV-2 cell entry and replication by inhibiting the main protease (Mpro) and RNA-dependent RNA polymerase (RdRp). The cytokine storm can be ameliorated by lowering serum IL-6 levels; this can be achieved by inhibiting Toll-like receptor 4 (TLR4) and modulating macrophage activity. Statins can also reduce the complications of COVID-19, such as thrombosis and pulmonary fibrosis, by reducing serum PAI-1 levels, attenuating TGF-ß and VEGF in lung tissue, and improving endothelial function. Despite these benefits, statin therapy may have side effects that should be considered, such as elevated creatinine kinase (CK), liver enzyme and serum glucose levels, which are already elevated in severe COVID-19 infection. The present study analyzes the latest findings regarding the benefits and limitations of statin therapy in patients with COVID-19.

Cardiovascular risk and response to lipid lowering therapy in patients with HIV infection according to different recommendations.

BACKGROUND: HIV patients are at increased cardiovascular risk while available European cardiovascular recommendations are ambiguous. METHODS: Retrospective analysis of 389 HIV-patients was conducted. Cardiovascular risk was determined by D:A:D, Framingham and SCORE scales. Patients were divided into risk groups as recommended by EACS 2019, PTN AIDS 2019 and ESC/EAS 2019 Guidelines and hypolipemic treatment was evaluated. RESULTS: In total, 389 HIV-positive patients took part in the study, most of whom were men (n = 312, 80.4%), mean age 41.69±10years. Mean lipid levels among all HIV patients: Tch:177.2±36mg/dl, HDL:48.9±18mg/dl, LDL:103.8±31mg/dl, TG:143.3±81mg/dl, AIP:0.45±0.3, non-HDL:129.2±36 mg/dl. Most of the participants (n = 360, 92.5%) were assigned to the high cardiovascular risk group according to ESC/EAS and PTN AIDS guidelines. The achievement of therapeutic LDLs according to ESC/EAS was 10.3% for those at very high cardiovascular risk (8.7% on lipid lowering treatment vs. 16.7% without hypolipemic drugs) and 12.0% (5.8% treated vs. 13.6% untreated) at high cardiovascular risk; according to PTN AIDS,17.2% achievement was noted by the very high-risk group (13% treated vs. 33.3% untreated), and 45.9% for the high-risk group (37.7% treated vs. 48.0% untreated); according to EACS Guidelines, 2.5% achievement in secondary prevention (3.8% treatedvs. 0% untreated) and 24.7% in primary prevention (22.2% treated vs. 26.1% untreated). Mean doses of statins were 8.75mg±6mg (Rosuvastatin) and 22.35±19mg (Atorvastatin). CONCLUSIONS: The achievement of therapeutic LDLs by all recommendations is unsatisfactory, and generally worse in patients on lipid lowering therapy. Hypolipemic treatment of our HIV patients is based on low doses of statins, even in secondary prevention.