Effect of PCSK9 inhibitor on lipoprotein particles in patients with acute coronary syndromes

Efficacy and Safety of PSCK9 Inhibitors on Patients with Acute Coronary Syndrome: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Background

PCSK9 MaB (Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor) may reduce the occurrence of major adverse cardiovascular events (MACEs) in patients diagnosed with acute coronary syndrome (ACS). In this meta-analysis, we conducted a thorough compilation of evidence from established clinical studies to evaluate PCSK9 MaB's capacity to control blood lipid levels and prevent MACEs in ACS patients.

Methods

We conducted searches on Pubmed, Embase, the Cochrane Library, and Web of Science to identify relevant articles. Data from ACS patients were extracted using a standardized format for aggregating data. We calculated the risk ratio (RR) for MACE and assessed changes in blood lipid parameters. All statistical analyses were performed using RevMan.

Results

11 articles representing 5 trials were included in our systematic review and meta-analysis. When compared to a placebo, PCSK9 MaB significantly reduced the risk of MACEs ( I 2 = 0%, p = 0.63, RR [95% CI] = 0.88 [0.81, 0.97], p < 0.01) and the recurrence rate of ACS ( I 2 = 45%, p = 0.18, RR [95% CI] = 0.89 [0.83, 0.95], p < 0.01). Additionally, PCSK9 MaB notably reduced low-density lipoprotein cholesterol (LDL-C) levels (SMD [95% CI] = -2.12 [-2.32, -1.92], p < 0.01) and Apolipoprotein B (ApoB) levels (SMD [95% CI] = -1.83 [-2.48, -1.18], p < 0.01). Importantly, there were no significant differences in adverse reactions between the PCSK9 MaB group and the control group.

Conclusions

PCSK9 MaB, whether used as a standalone treatment or in combination with other therapies, can effectively inhibit PCSK9. It substantially lowers key blood lipid parameters, including low-density lipoprotein (LDL), ApoB, and triglycerides, all without giving rise to notable safety concerns.

Effect of PCSK9 inhibition on plasma levels of small dense low density lipoprotein-cholesterol and 7-ketocholesterol

BACKGROUND

Oxidized forms of cholesterol (oxysterols) are implicated in atherogenesis and can accumulate in the body via direct absorption from food or through oxidative reactions of endogenous cholesterol, inducing the formation of LDL particles loaded with oxidized cholesterol. It remains unknown whether drastic reductions in LDL-cholesterol (LDL-C) are associated with changes in circulating oxysterols and whether small dense LDL (sdLDL) are more likely to carry these oxysterols and susceptible to the effects of PCSK9 inhibition (PCSK9i).

OBJECTIVE

We investigate the effect of LDL-C reduction accomplished via PCSK9i on changes in plasma levels of sdLDL-cholesterol (sdLDL-C) and a common, stable oxysterol, 7-ketocholesterol (7-KC), among 134 patients referred to our Preventive Cardiology clinic.

METHODS

Plasma lipid panel, sdLDL-C, and 7-KC measurements were obtained from patients before and after initiation of PCSK9i.

RESULTS

The intervention caused a significant lowering of LDL-C (-55.4 %). The changes in sdLDL-C levels (mean reduction 51.4 %) were highly correlated with the reductions in LDL-C levels (R = 0.829, p < 0.001). Interestingly, whereas changes in plasma free 7-KC levels with PCSK9i treatment were much smaller than (-6.6 %) and did not parallel those of LDL-C and sdLDL-C levels, they did significantly correlate with changes in triglycerides and very low-density lipoprotein-cholesterol (VLDL-C) levels (R = 0.219, p = 0.025).

CONCLUSION

Our findings suggest a non-preferential clearance of LDL subparticles as a consequence of LDL receptor upregulation caused by PCSK9 inhibition. Moreover, the lack of significant reduction in 7-KC with PCSK9i suggests that 7-KC may be in part carried by VLDL and lost during lipoprotein processing leading to LDL formation.

Mesenchymal stem cell-derived extracellular vesicles for metabolic syndrome therapy: Assessing efficacy with nuclear magnetic resonance spectroscopy

Metabolic syndrome (MetS) represents a cluster of metabolic abnormalities. The prevalence of MetS has surged, transforming it into a pressing public health concern that could potentially affect around 20%-25% of the global population. As MetS continues its ascent, diverse interventions, pharmacological, nonpharmacological and combined have been deployed. Yet, a comprehensive remedy that fully eradicates MetS symptoms remains elusive, compounded by the risks of polypharmacy's emergence. Acknowledging the imperative to grasp MetS's intricate pathologies, deeper insights for future research and therapy optimisation become paramount. Conventional treatments often target specific syndrome elements. However, a novel approach emerges in mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) therapy, promising a holistic shift. MSC-EVs, tiny membranous vesicles secreted by mesenchymal stem cells, have garnered immense attention for their multifaceted bioactivity and regenerative potential. Their ability to modulate inflammation, enhance tissue repair and regulate metabolic pathways has prompted researchers to explore their therapeutic application in MetS. This review primarily aims to provide an overview of how MSC-EVs therapy can improve metabolic parameters in subjects with MetS disease and also introduce the usefulness of NMR spectroscopy in assessing the efficacy of MSC-EVs therapy for treating MetS.

Administration of insulin like growth factor I (IGFI) lowers serum lipoprotein(a)-impact on atherosclerotic cardiovascular disease

Insulin like growth factor I (IGFI) secreted by the liver upon stimulation by pituitary growth hormone (GH) acts as the most important growth stimulating hormone in children. The present review presents evidence that among its additional metabolic effects, IGF-I suppresses the synthesis of lipoprotein(a) [Lp(a)], an independent risk factor for atherosclerotic cardiovascular disease. In view of this property, it is suggested that the addition of IGF-I to the armamentarium of hyperlipoproteinemia treatment should be considered.

Serum lipoprotein(a) predicts 1-year major cardiovascular events in patients after percutaneous coronary intervention

BACKGROUND

Lipoprotein(a) [Lp(a)], which is predictive of coronary heart disease (CHD), plays an important role in the pathogenesis of atherosclerosis. This study aimed to evaluate the association of Lp(a) with major adverse cardiovascular events (MACEs) and readmission in individuals who had undergone a percutaneous coronary intervention (PCI).

METHODS

A total of 1,938 patients with CHD who had undergone a PCI from January 2010 to December 2018 were assigned to three groups based on Lp(a) level. Follow-up was performed to assess the 1-year occurrence of MACEs and readmission.

RESULTS

Kaplan-Meier survival curves showed that the cumulative hazard incidence rate of MACEs and repeat PCI (re-PCI) significantly increased with Lp(a) level. Multivariate Cox proportional hazards regression analysis further confirmed Lp(a) as a significant independent predictor of MACEs. The area under the curve of the complex index risk score was significantly larger than those of other independent indicators. In individuals with low-density lipoprotein-cholesterol (LDL-C) levels either below 70 mg/dL or between 70 mg/dL and 100 mg/dL, Lp(a) was associated with increased rates of MACEs and readmission. In addition, a nomogram was constructed to predict 1-year MACE.

CONCLUSIONS

High Lp(a) levels may be a residual risk factor for MACEs in individuals with LDL-C levels under 100 mg/dL. Additionally, the built nomogram could predict 1-year MACEs with high accuracy. Lp(a) independently predicts 1-year MACEs, indicating its importance in risk assessment and the selection of clinical strategies in patients who have undergone a PCI.

Effects of PCSK9 inhibitors on HDL cholesterol efflux and serum cholesterol loading capacity in familial hypercholesterolemia subjects: a multi-lipid-center real-world evaluation

Proprotein convertase subtilisin/kexin type 9 (PCSK9), beyond regulating LDL cholesterol (LDL-c) plasma levels, exerts several pleiotropic effects by modulating lipid metabolism in extrahepatic cells such as macrophages. Macrophage cholesterol homeostasis depends on serum lipoprotein functions, including the HDL capacity to promote cell cholesterol efflux (CEC) and the serum capacity to promote cell cholesterol loading (CLC). The aim of this observational study was to investigate the effect of PCSK9 inhibitors (PCSK9-i) treatment on HDL-CEC and serum CLC in patients with familial hypercholesterolemia (FH). 31 genetically confirmed FH patients were recruited. Blood was collected and serum isolated at baseline and after 6 months of PCSK9-i treatment. HDL-CEC was evaluated through the main pathways with a radioisotopic cell-based assay. Serum CLC was assessed fluorimetrically in human THP-1 monocyte-derived macrophages. After treatment with PCSK9-i, total cholesterol and LDL-c significantly decreased (−41.6%, p < 0.0001 and −56.7%, p < 0.0001, respectively). Total HDL-CEC was not different between patients before and after treatment. Conversely, despite no changes in HDL-c levels between the groups, ABCG1 HDL-CEC significantly increased after treatment (+22.2%, p < 0.0001) as well as HDL-CEC by aqueous diffusion (+7.8%, p = 0.0008). Only a trend towards reduction of ABCA1 HDL-CEC was observed after treatment. PCSK9-i significantly decreased serum CLC (−6.6%, p = 0.0272). This effect was only partly related to the reduction of LDL-c levels. In conclusion, PCSK9-i treatment significantly increased HDL-CEC through ABCG1 and aqueous diffusion pathways and reduced the serum CLC in FH patients. The favorable effect of PCSK9-i on functional lipid profile could contribute to the cardiovascular benefit of these drugs in FH patients.

Effect of PCSK9 inhibition with evolocumab on lipoprotein subfractions in familial dysbetalipoproteinemia (type III hyperlipidemia)

BACKGROUND AND AIMS

Familial dysbetalipoproteinemia (FDBL) is a rare inborn lipid disorder characterized by the formation of abnormal triglyceride- and cholesterol-rich lipoproteins (remnant particles). Patients with FDBL have a high risk for atherosclerotic disease. The effect of PCSK9 inhibition on lipoproteins and its subfractions has not been evaluated in FDBL.

METHODS

Three patients (65±7 years, 23±3 kg/m2, 2 females) with FDBL (diagnosed by isoelectrofocusing) and atherosclerosis (coronary and/or cerebro-vascular and/or peripheral arterial disease) resistant or intolerant to statin and fibrate therapy received evolocumab (140mg every 14 days). In addition to a fasting lipid profile (preparative ultracentrifugation), apoB and cholesterol concentrations were determined in 15 lipoprotein-subfractions (density gradient ultracentrifugation; d 1.006-1.21g/ml) before and after 12 weeks of evolocumab treatment. Patients with LDL-hypercholesterolemia (n = 8, 56±8 years, 31±7 kg/m2) and mixed hyperlipidemia (n = 5, 68±12 years, 30±1 kg/m2) also receiving evolocumab for 12 weeks were used for comparison.

RESULTS

All patients tolerated PCSK9 inhibition well. PCSK9 inhibitors reduced cholesterol (29-37%), non-HDL-cholesterol (36-50%) and apoB (40-52%) in all patient groups including FDBL. In FDBL, PCSK9 inhibition reduced VLDL-cholesterol and the concentration of apoB containing lipoproteins throughout the whole density spectrum (VLDL, IDL, remnants, LDL). Lipoprotein(a) was decreased in all patient groups to a similar extent.

CONCLUSIONS

This indicates that the dominant fraction of apoB-containing lipoproteins is reduced with PCSK9 inhibition, i.e. LDL in hypercholesterolemia and mixed hyperlipidemia, and cholesterol-rich VLDL, remnants and LDL in FDBL. PCSK9 inhibition may be a treatment option in patients with FDBL resistant or intolerant to statin and/or fibrate therapy.

High-Density Lipoprotein Subfractions: Much Ado about Nothing or Clinically Important?

High-density lipoproteins (HDL) are a heterogenous group of plasma molecules with a large variety in composition. There is a wide specter in lipid content and the number of different proteins that has been associated with HDL is approaching 100. Given this heterogeneity and the fact that the total amount of HDL is inversely related to the risk of coronary heart disease (CHD), there has been increasing interest in the function of specific HDL subgroups and in what way measuring and quantifying these subgroups could be of clinical importance in determining individual CHD risk. If certain subgroups appear to be more protective than others, it may also in the future be possible to pharmacologically increase beneficial and decrease harmful subgroups in order to reduce CHD risk. In this review we give a short historical perspective, summarize some of the recent clinical findings regarding HDL subclassifications and discuss why such classification may or may not be of clinical relevance.