Inclisiran in lipid management: A Literature overview and future perspectives.

Primary and secondary prevention protocols aim at reducing the plasma levels of lipids - with particular reference to low-density lipoprotein cholesterol (LDL-C) plasma concentrations - in order to improve the overall survival and reduce the occurrence of major adverse cardiovascular events. The use of statins has been widely considered as the first-line approach in lipids management as they can dramatically impact on the cardiovascular risk profile of individuals. The introduction of ezetimibe and proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors overcame the adverse effects of statins and ameliorate the achievement of the target lipids levels. Indeed, advances in therapies promote the use of specific molecules - i.e. short strands of RNA named small-interfering RNAs (siRNAs) - to suppress the transcription of genes related to lipids metabolism. Recently, the inclisiran has been developed: this is a siRNA able to block the mRNA of the PCSK9 gene. About 50% reduction in low-density lipoprotein cholesterol levels have been observed in randomized controlled trials with inclisiran. The aim of this review was to summarize the literature regarding inclisiran and its possible role in the general management of patients with lipid disorders and/or in primary/secondary prevention protocols.

PCSK9 Biology and Its Role in Atherothrombosis.

It is now about 20 years since the first case of a gain-of-function mutation involving the as-yet-unknown actor in cholesterol homeostasis, proprotein convertase subtilisin/kexin type 9 (PCSK9), was described. It was soon clear that this protein would have been of huge scientific and clinical value as a therapeutic strategy for dyslipidemia and atherosclerosis-associated cardiovascular disease (CVD) management. Indeed, PCSK9 is a serine protease belonging to the proprotein convertase family, mainly produced by the liver, and essential for metabolism of LDL particles by inhibiting LDL receptor (LDLR) recirculation to the cell surface with the consequent upregulation of LDLR-dependent LDL-C levels. Beyond its effects on LDL metabolism, several studies revealed the existence of additional roles of PCSK9 in different stages of atherosclerosis, also for its ability to target other members of the LDLR family. PCSK9 from plasma and vascular cells can contribute to the development of atherosclerotic plaque and thrombosis by promoting platelet activation, leukocyte recruitment and clot formation, also through mechanisms not related to systemic lipid changes. These results further supported the value for the potential cardiovascular benefits of therapies based on PCSK9 inhibition. Actually, the passive immunization with anti-PCSK9 antibodies, evolocumab and alirocumab, is shown to be effective in dramatically reducing the LDL-C levels and attenuating CVD. While monoclonal antibodies sequester circulating PCSK9, inclisiran, a small interfering RNA, is a new drug that inhibits PCSK9 synthesis with the important advantage, compared with PCSK9 mAbs, to preserve its pharmacodynamic effects when administrated every 6 months. Here, we will focus on the major understandings related to PCSK9, from its discovery to its role in lipoprotein metabolism, involvement in atherothrombosis and a brief excursus on approved current therapies used to inhibit its action.

Fatty acid desaturase 2 (FADS 2) rs174575 (C/G) polymorphism, circulating lipid levels and susceptibility to type-2 diabetes mellitus.

Several factors influence an individual's susceptibility in inter-individual lipid changes and its role in the onset of type-2 diabetes mellitus (T2DM). Considering the above fact, the present investigation focuses on determining the association between fatty acid desaturase 2 (FADS2) rs174575 (C/G) polymorphism, circulating lipid levels and susceptibility to type-2 diabetes mellitus. As per the inclusion and exclusion criteria a total of 429 subjects (non-diabetic-216; diabetic-213) were recruited for the study. Glycemic and lipid profile status were assessed using commercially available kits. Based on the previous reports SNP rs174575 of fatty acid desaturase gene (FADS2) was selected and identified using the dbSNP database. The amplified products were sequenced by means of Sanger sequencing method. Lipid profile status and apolipoprotein levels revealed statistically significant difference between the groups. Three models were assessed namely, recessive model (CC vs CG + GG), dominant model (CC + CG vs GG) and additive model (CC vs CG vs GG). The recessive model, displayed a statistically significant variations between the circulating lipid levels in T2DM. The multivariate model with genotype (G allele carriers), triglyceride (TG) and insulin served as a predictive model. The study results potentiate the functional link between FADS2 gene polymorphism, lipid levels and type-2 diabetes mellitus.

Imperatorin alleviates metabolic and vascular alterations in high-fat/high-fructose diet-fed rats by modulating adiponectin receptor 1, eNOS, and p47phox expression.

In the present study, the therapeutic effects of imperatorin on metabolic and vascular alterations and possible underlying mechanisms were investigated in high-fat/high-fructose diet (HFFD)-fed rats. Male Sprague-Dawley rats were fed a high-fat diet plus 15% fructose in drinking water for 16 weeks. HFFD-fed rats were treated with imperatorin (15 or 30 mg/kg/day) for the last 4 weeks. In HFFD-fed rats, imperatorin significantly reduced obesity, hypertension, dyslipidemia, and insulin resistance. Imperatorin markedly improved vascular endothelial function and alleviated changes in vascular morphology. Furthermore, imperatorin treatment significantly increased the plasma levels of the nitric oxide metabolite and adiponectin, and upregulated adiponectin receptor 1 and endothelial nitric oxide synthase (eNOS) protein expression in the thoracic aorta. Imperatorin treatment decreased vascular superoxide anion production and downregulated aortic NADPH oxidase subunit p47phox protein expression. These findings indicated that imperatorin alleviates HFFD-induced metabolic and vascular alterations in rats. The possible underlying mechanism may involve the restoration of adiponectin receptor 1 and eNOS expression and suppression of p47phox expression.

AMPK activator C24 inhibits hepatic lipogenesis and ameliorates dyslipidemia in HFHC diet-induced animal models.

Dyslipidemia is a chronic metabolic disease characterized by elevated levels of lipids in plasma. Recently, various studies demonstrate that the increased activity of adenosine 5'-monophosphate-activated protein kinase (AMPK) causes health benefits in energy regulation. Thus, great efforts have been made to develop AMPK activators as a metabolic syndrome treatment. In the present study, we investigated the effects of the AMPK activator C24 on dyslipidemia and the potential mechanisms. We showed that C24 (5-40 µM) dose-dependently increased the phosphorylation of AMPKα and acetyl-CoA carboxylase (ACC), and inhibited lipogenesis in HepG2 cells. Using compound C, an AMPK inhibitor, or hepatocytes isolated from liver tissue-specific AMPK knockout AMPKα1α2fl/fl;Alb-cre mice (AMPK LKO), we demonstrated that the lipogenesis inhibition of C24 was dependent on hepatic AMPK activation. In rabbits with high-fat and high-cholesterol diet-induced dyslipidemia, administration of C24 (20, 40, and 60 mg · kg-1· d-1, ig, for 4 weeks) dose-dependently decreased the content of TG, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) in plasma and played a role in protecting against hepatic dysfunction by decreasing lipid accumulation. A lipid-lowering effect was also observed in high-fat and high-cholesterol diet-fed hamsters. In conclusion, our results demonstrate that the small molecular AMPK activator C24 alleviates hyperlipidemia and represents a promising compound for the development of a lipid-lowering drug.

Lipoprotein(a) Reduction With Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors: A Systematic Review and Meta-analysis.

ABSTRACT: Lipoprotein(a) [Lp(a)] is a cardiovascular factor, for which there is no approved specific lowering treatment. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been shown to have lowering effects on Lp(a). Aim of this systematic review is to synthesize the current literature and quantify the effects of PCSK9 inhibitors on the serum Lp(a) levels in human subjects. Double-blind, phase 2 or 3, randomized-controlled trials comparing PCSK9 inhibitors (alirocumab or evolocumab) to placebo and/or ezetimibe and/or other lipid-lowering therapy were deemed eligible for inclusion. We searched MEDLINE (via PubMed), CENTRAL, Scopus, and Web of Science as of 17 June 2020. Quality assessment was performed using the Revised Cochrane risk-of-bias tool for randomized trials. Forty-three studies were identified (64,107 patients randomized) and 41 studies were included in the quantitative analysis. PCSK9 inhibitors reduced Lp(a) levels by -26.7% (95% CI, -29.5% to -23.9%) with a significant heterogeneity within studies. There was significant difference in Lp(a) change from baseline according to comparator (placebo: mean -27.9%; 95% CI, -31.1% to -24.6% vs. ezetimibe: mean, -22.2%; 95% CI, -27.2% to -17.2%; P = 0.04) and duration of treatment (≤12 weeks: mean, -30.9%; 95% CI, -34.7% to -27.1% vs. >12 weeks: mean, -21.9%; 95% CI, -25.2% to -18.6%; P < 0.01). Meta-regression analysis showed that only the mean percentage change from baseline low-density lipoprotein cholesterol due to the intervention is significantly associated with the effect size difference (P < 0.0001). PCSK9 inhibitors reduced low-density lipoprotein cholesterol by -54% (95% CI -57.6% to -50.6%). There is substantial efficacy of the currently approved PCSK9 inhibitors in the lowering of Lp(a) levels. Dedicated randomized controlled trials are needed to establish the benefit of this intervention.

Lysozyme is a component of the innate immune system linked to obesity associated-chronic low-grade inflammation and altered glucose tolerance.

BACKGROUND & AIMS: Several proteins of the innate immune system are known to be deregulated with insulin resistance. We here aimed to investigate the relationship among circulating lysozyme (both plasma concentration and activity) and obesity-associated metabolic disturbances. METHODS: Plasma lysozyme concentration was determined cross-sectionally in a discovery (Cohort 1, n = 137) and in a replication cohort (Cohort 2, n = 181), in which plasma lysozyme activity was also analyzed. Plasma lysozyme was also evaluated longitudinally in participants from the replication cohort (n = 93). Leukocyte lysozyme expression (LYZ mRNA) were also investigated in an independent cohort (Cohort 3, n = 76), and adipose tissue (AT) LYZ mRNA (n = 25) and plasma peptidoglycan levels (n = 61) in subcohorts from discovery cohort. RESULTS: Translocation of peptidoglycan (as inferred from its increased circulating levels) was linked to plasma lysozyme, hyperinsulinemia and dyslipidemia in obese subjects. In both discovery and replication cohorts, plasma lysozyme levels and activity were significantly increased in obesity in direct association with obesity-associated metabolic disturbances and inflammatory parameters, being circulating lysozyme negatively correlated with fasting glucose, HbA1c and insulin resistance (HOMA-IR) in obese subjects. Of note, total cholesterol (p < 0.0001) and LDL cholesterol (p = 0.003) contributed independently to age-, gender- and BMI adjusted plasma lysozyme activity. Longitudinally, changes in HbA1c levels and serum LDL cholesterol were negatively associated with circulating lysozyme antimicrobial activity. On the contrary, the change in glucose infusion rate during the clamp (insulin sensitivity) was positively associated with lysozyme concentration. CONCLUSIONS: Increased plasma lysozyme levels and activity are found in obese subjects. The longitudinal findings suggest that plasma lysozyme might be protective on the development of obesity-associated metabolic disturbances.

Lipocalin-type prostaglandin D2 synthase deletion induces dyslipidemia and non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is an emerging risk factor for type 2 diabetes mellitus, cardiovascular disease, and all-cause mortality. Previously, we demonstrated that lipocalin-type prostaglandin D2 synthase (L-PGDS) knockout mice show increased glucose intolerance and accelerated atherosclerosis. In the present study, we investigated the role of L-PGDS in mediating NAFLD utilizing L-PGDS knockout (KO) and control C57BL/6 mice fed either low fat (LFD) or high fat diet (HFD) for 14 weeks. Our present study demonstrates that L-PGDS KO mice remain slightly lighter in weight compared to control mice, yet develop NAFLD faster and eventually progress to the more severe non-alcoholic steatohepatitis (NASH). We found increased lipid accumulation in the liver of KO mice over time on both diets, as compared to control mice. The L-PGDS KO mice showed elevated fasting glucose and insulin levels and developed insulin resistance on both LFD and HFD. Lipogenesis marker proteins such as SREBP-1c and LXRα were increased in L-PGDS KO mice after 14 weeks on both diets, when compared to control mice. We replicated our in vivo findings in vitro using HepG2 cells treated with a combination of free fatty acids (oleic and palmitic acid) and exposure to a L-PGDS inhibitor and prostaglandin D2 receptor (DP1) antagonists. We conclude that the absence or inhibition of L-PGDS results in dyslipidemia, altered expression of lipogenesis genes and the acceleration of NAFLD to NASH, independent of diet and obesity. We propose L-PGDS KO mice as a useful model to explore the pathogenesis of NAFLD and NASH, and L-PGDS as a potential therapeutic target for treatment.

Research progress on alternative non-classical mechanisms of PCSK9 in atherosclerosis in patients with and without diabetes.

The proprotein convertase subtilisin/kexin type 9 (PCSK9) acts via a canonical pathway to regulate circulating low-density lipoprotein-cholesterol (LDL-C) via degradation of the LDL receptor (LDLR) on the liver cell surface. Published research has shown that PCSK9 is involved in atherosclerosis via a variety of non-classical mechanisms that involve lysosomal, inflammatory, apoptotic, mitochondrial, and immune pathways. In this review paper, we summarized these additional mechanisms and described how anti-PCSK9 therapy exerts effects through these mechanisms. These additional pathways further illustrate the regulatory role of PCSK9 in atherosclerosis and offer an in-depth interpretation of how the PCSK9 inhibitor exerts effects on the treatment of atherosclerosis.

From Endothelium to Lipids, Through microRNAs and PCSK9: A Fascinating Travel Across Atherosclerosis.

Lipids and endothelium are pivotal players on the scene of atherosclerosis and their interaction is crucial for the establishment of the pathological processes. The endothelium is not only the border of the arterial wall: it plays a key role in regulating circulating fatty acids and lipoproteins and vice versa it is regulated by these lipidic molecules thereby promoting atherosclerosis. Inflammation is another important element in the relationship between lipids and endothelium. Recently, proprotein convertase subtilisin/kexin type 9 (PCSK9) has been recognized as a fundamental regulator of LDL-C and anti-PCSK9 monoclonal antibodies have been approved for therapeutic use in hypercholesterolemia, with the promise to subvert the natural history of the disease. Moreover, growing experimental and clinical evidence is enlarging our understanding of the mechanisms through which this protein may facilitate the genesis of atherosclerosis, independently of its impact on lipid metabolism. In addition, environmental stimuli may affect the post-transcriptional regulation of genes through micro-RNAs, which in turn play a key role in orchestrating the crosstalk between endothelium and cholesterol. Advances in experimental research, with development of high throughput techniques, have led, over the last century, to a tremendous progress in the understanding and fine tuning of the molecular mechanisms leading to atherosclerosis. Identification of pivotal keystone molecules bridging lipid metabolism, endothelial dysfunction and atherogenesis will provide the mechanistic substrate to test valuable targets for prediction, prevention and treatment of atherosclerosis-related disease.

[Association of health literacy with hypertension, diabetes, and dyslipidemia: A cross-sectional survey of a regional Japanese community].

Objectives　This study aimed to identify how communicative and critical health literacy (CCHL) was associated with hypertension, diabetes, and dyslipidemia in a regional Japanese community.Methods　A cross-sectional survey was conducted through stratified random sampling to achieve the study objectives. The sample comprised adults aged 20-75 years, residing in Ebetsu in Hokkaido, Japan. Stratification was accomplished by classifying the population into 3 districts of Ebetsu city, with 1,000 people being randomly selected from each district. A self-reporting questionnaire was then administered over July and August 2018 to these 3,000 participants. Ebetsu city officials distributed and collected the questionnaires, delivering anonymized data to the researchers. Of the 1,630 respondents, 8 did not complete the CCHL questionnaire and 43 did not fill the disease status questionnaire, so these were excluded. The final analysis was performed on the responses received from 692 men and 887 women. The CCHL scores were grouped into quartiles to identify trends related to the diseases and lifestyles. A multiple logistic regression analysis was performed to estimate the associations between CCHL and instances of hypertension, diabetes, and dyslipidemia in both sexes. The analysis was adjusted for age, living arrangement, marital status, educational attainment, current employment status, body mass index, frequency of regular exercise, habit of skipping breakfast, and smoking status.Results　The overall CCHL score was computed as 3.58±0.67 (mean±SD). Among men, the prevalence of hypertension in the highest CCHL score group was significantly lower than that in the lowest CCHL group (OR 0.49; 95%CI: 0.28-0.84). The analysis indicated that the prevalence of hypertension among men was low for the highest CCHL score group (AOR 0.62; 95%CI: 0.32-1.22). Associations between CCHL scores and other diseases were found to be non-significant in both men and women.Conclusion　Male participants with the highest CCHL scores had a significantly lower prevalence of hypertension than those with the lowest CCHL scores. However, these associations were found to be non-significant after adjusting for confounding factors. Future studies on the association of CCHL with lifestyle disorders should apply a longitudinal design.

What Proportion of Patients Admitted with Stroke or Transient Ischemic Attack May Be Suitable for Newer Cholesterol-Lowering Treatment?

BACKGROUND: Protein convertase subtilisin-kexin type 9 (PCSK9) inhibitors effectively clear low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C). We evaluated stroke admissions potentially eligible for more intensive cholesterol treatment. METHODS: Retrospective analysis of consecutive admissions to a hyperacute stroke unit over 5 months in 2017. Records were individually searched. Data were collected on diagnosis, risk factors, and stroke work-up. European Society of Cardiology and European Atherosclerosis Society guidelines for the management of dyslipidaemias were used for screening patients eligible for PCSK9 inhibitors. RESULTS: Of 650 patient admissions: 351 (54%) had acute ischemic stroke or transient ischemic attack (TIA), 80 (12%) hemorrhage, and 219 (34%) mimic syndromes. Patients with hemorrhage (n = 80), mimic syndromes (n = 219), and absent LDL-C, or non-HDL-C testing (n = 27) were subsequently excluded. 324 patients with acute ischemic stroke and TIA were further screened for PCSK9-inhibitor treatment eligibility. Forty-one (13%) patients with LDL-C greater than or equal to 1.8mmol/L (≥70 mg/dL) on maximal tolerated statin dose and with concomitant "very high vascular risk" were identified. "Very high vascular risk" was defined as a documented history of cardiovascular disease and/or peripheral arterial disease. Of 41 patients eligible for PCSK9 inhibitors, median age was 82 years (range 53-96); median vascular risk factors were 2 (range 1-5); 7 (17%) had TIA; 13 (31%) had history of preceding cerebrovascular events, 13 (31%) diabetes mellitus, 17 (42%) cardioembolic events, 9 (22%) lacunar syndrome, 11 (22%) symptomatic internal carotid artery stenosis (n = 9 were >70%), and 4 (10%) undetermined aetiology. Eighty-three percent patients eligible for PCSK9 inhibitors also had non-HDL-C values greater than or equal to 2.6 mmol/L. CONCLUSIONS: Up to 13% of unselected acute ischemic stroke or TIA patients admitted to a hyper-acute stroke unit were potentially suitable for more intensive cholesterol treatment. Our data may act as a useful guide for sample size selection in future stroke trials testing PCSK9 inhibitors.

PCSK9 and inflammation: role of shear stress, pro-inflammatory cytokines, and LOX-1.

PCSK9 degrades low-density lipoprotein cholesterol (LDL) receptors and subsequently increases serum LDL cholesterol. Clinical trials show that inhibition of PCSK9 efficiently lowers LDL cholesterol levels and reduces cardiovascular events. PCSK9 inhibitors also reduce the extent of atherosclerosis. Recent studies show that PCSK9 is secreted by vascular endothelial cells, smooth muscle cells, and macrophages. PCSK9 induces secretion of pro-inflammatory cytokines in macrophages, liver cells, and in a variety of tissues. PCSK9 regulates toll-like receptor 4 expression and NF-κB activation as well as development of apoptosis and autophagy. PCSK9 also interacts with oxidized-LDL receptor-1 (LOX-1) in a mutually facilitative fashion. These observations suggest that PCSK9 is inter-twined with inflammation with implications in atherosclerosis and its major consequence-myocardial ischaemia. This relationship provides a basis for the use of PCSK9 inhibitors in prevention of atherosclerosis and related clinical events.

PCSK9 inhibition and inflammation: A narrative review.

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of morbidity and mortality despite excellent pharmacological and revascularization approaches. Low-density lipoproteins (LDL) are undoubtedly the most significant biochemical variables associated with atheroma, however, compelling data identify inflammation as critical for the maintenance of the atherosclerotic process, underlying some of the most feared vascular complications. Although its causal role is questionable, high-sensitivity C-reactive protein (hs-CRP) represents a major biomarker of inflammation and associated risk in CVD. While statin-associated reduced risk may be related to the lowering of both LDL-C and hs-CRP, PCSK9 inhibitors leading to dramatic LDL-C reductions do no alter hs-CRP levels. On the other hand, hs-CRP levels identify groups of patients with a high risk of CV disease achieving better ASCVD prevention in response to PCSK9 inhibition. In the FOURIER study, even in patients with extremely low levels of LDL-C, there was a stepwise risk increment according to the values of hs-CRP: +9% (<1 mg/L), +10.8% (1-3 mg/L) and +13.1% (>3 mg/L). Likewise, in the SPIRE-1 and -2 studies, bococizumab patients with hs-CRP> 3 mg/L had a 60% greater risk of future CV events. Most of the patients enrolled in the PCSK9 trials were on maximally tolerated statin therapy at baseline, and an elevated hs-CRP may reflect residual inflammatory risk after standard LDL-C lowering therapy. Moreover, data on changes in inflammation markers in carriers of PCSK9 loss-of-function mutations are scanty and not conclusive, thus, evidence from the effects of anti-inflammatory molecules on PCSK9 levels might help unravel this hitherto complex tangle.

Treatment with fibrates is associated with higher LAL activity in dyslipidemic patients.

Lysosomal acid lipase (LAL) is responsible for the hydrolysis of cholesteryl esters (CE) and triglycerides (TG) within the lysosomes; generated cholesterol and free fatty acids (FFA) are released in the cytosol where they can regulate their own synthesis and metabolism. When LAL is not active, as in case of genetic mutations, CE and TG accumulate in the lysosomal compartment, while the lack of release of cholesterol and FFA in the cytosol leads to an upregulation of their synthesis. Thus, LAL plays a central role in the intracellular homeostasis of lipids. Since there are no indications about the effect of different lipid-lowering agents on LAL activity, aim of the study was to address the relationship between LAL activity and the type of lipid-lowering therapy in a cohort of dyslipidemic patients. LAL activity was measured on dried blood spot from 120 patients with hypercholesterolemia or mixed dyslipidemia and was negatively correlated to LDL-cholesterol levels. Among enrolled patients, ninety-one were taking one or more lipid-lowering drugs, as statins, fibrates, ezetimibe and omega-3 polyunsaturated fatty acids. When patients were stratified according to the type of lipid-lowering treatment, i.e. untreated, taking statins or taking fibrates, LAL activity was significantly higher in those with fibrates, even after adjustment for sex, age, BMI, lipid parameters, liver function, metabolic syndrome, diabetes and statin use. In a subset of patients tested after 3 months of treatment with micronized fenofibrate, LAL activity raised by 21%; the increase was negatively correlated with baseline LAL activity. Thus, the use of fibrates is independently associated with higher LAL activity in dyslipidemic patients, suggesting that the positive effects of PPAR-α activation on cellular and systemic lipid homeostasis can also include an improved LAL activity.

JNK and cardiometabolic dysfunction.

Cardiometabolic syndrome (CMS) describes the cluster of metabolic and cardiovascular diseases that are generally characterized by impaired glucose tolerance, intra-abdominal adiposity, dyslipidemia, and hypertension. CMS currently affects more than 25% of the world's population and the rates of diseases are rapidly rising. These CMS conditions represent critical risk factors for cardiovascular diseases including atherosclerosis, heart failure, myocardial infarction, and peripheral artery disease (PAD). Therefore, it is imperative to elucidate the underlying signaling involved in disease onset and progression. The c-Jun N-terminal Kinases (JNKs) are a family of stress signaling kinases that have been recently indicated in CMS. The purpose of this review is to examine the in vivo implications of JNK as a potential therapeutic target for CMS. As the constellation of diseases associated with CMS are complex and involve multiple tissues and environmental triggers, carefully examining what is known about the JNK pathway will be important for specificity in treatment strategies.

Low Density Lipoprotein (LDL) Cholesterol as a Causal Role for Atherosclerotic Disease: Potential Role of PCSK9 Inhibitors.

Proprotein convertase subtilisin/kexin type 9 (PCSK9)-related discoveries of the turn of the century have translated into substantial novelty in dyslipidemia treatment in the last 5 years. With chronic preventable atherosclerotic cardiovascular diseases (ASCVD) representing an epidemic of morbidity and mortality worldwide, low-density lipoprotein cholesterol (LDL-c) reduction represents a public health priority. By overcoming two major statin-related issues, namely intolerance and ineffectiveness, PCSK9 inhibitors have offered a safe and effective option in selected clinical settings where LDL-c reduction is required. Herein, we recapitulate recent findings, clinical applications, and ASCVD prevention potential of PCSK9 inhibition, with focus on anti-PCSK9 monoclonal antibodies, evolocumab and alirocumab.

A short review of proprotein convertase subtilisin/kexin type 9 inhibitors.

Cardiovascular disease is the leading cause of morbidity and mortality globally, as estimated by the World Health Organization, where in 2016, 15.2 million deaths were attributed to ischemic heart disease and stroke. It is therefore essential to try to reduce the incidence of Cardiovascular disease by controlling modifiable risk factors. One such major modifiable risk factor is cholesterol, which influences the pathogenesis and progression of atherosclerosis. Statins are often prescribed to lower blood levels of low density lipoprotein cholesterol, thereby reducing the risk of Cardiovascular disease by approximately 25-35%. However, there is an increasing number of patients (in particular those with intolerance to statin therapy and those with familial hypercholesterolemia) for whom statin therapy alone is not enough to control low density lipoprotein cholesterol. In this review, the regulation of cholesterol metabolism will be discussed with an emphasis on novel cholesterol lowering drugs used in clinical trials. These second-generation drugs, monoclonal antibodies against the low density lipoprotein receptor gene known as proprotein convertase subtilisin/kexin type 9 inhibitors, are expected to be prescribed to patients who are intolerant to statins, as well as in conjunction with statins. Future perspectives of the clinical use of these drugs is also discussed.

Lipoprotein(a) reductions from PCSK9 inhibition and major adverse cardiovascular events: Pooled analysis of alirocumab phase 3 trials.

BACKGROUND AND AIMS: Elevated lipoprotein(a) [Lp(a)] levels are considered a causal factor for cardiovascular disease. In phase 3 ODYSSEY trials, alirocumab reduced levels of low-density lipoprotein cholesterol (LDL-C) and Lp(a), with concomitant reductions in the risk of major adverse cardiovascular events (MACE). We assessed whether lower on-study and greater percentage reductions in Lp(a) are associated with a lower risk of MACE. METHODS: Post-hoc analysis of data pooled from 10 phase 3 ODYSSEY trials comparing alirocumab with control (placebo or ezetimibe) in patients (n = 4983) with cardiovascular disease and/or risk factors, and hypercholesterolemia despite statin/other lipid-lowering therapies. RESULTS: Median (Q1, Q3) baseline Lp(a) levels were 23.5 (8.0, 67.0) mg/dL. Median Lp(a) changes from baseline with alirocumab were -25.6% vs. -2.5% with placebo (absolute reductions 6.8 vs. 0.5 mg/dL) in placebo-controlled trials, and -21.4% vs. 0.0% with ezetimibe (4.5 vs. 0.0 mg/dL) in ezetimibe-controlled trials. During follow-up (6699 patient-years), 104 patients experienced MACE. A 12% relative risk reduction in MACE per 25% reduction in Lp(a) (p=0.0254) was no longer significant after adjustment for LDL-C changes: hazard ratio per 25% reduction: 0.89 (95% confidence interval, 0.79-1.01; p=0.0780). In subgroup analysis, the association between Lp(a) reduction and MACE remained significant in a fully adjusted model among participants with baseline Lp(a) ≥50 mg/dL (p-interaction vs. Lp(a) < 50 mg/dL: 0.0549). CONCLUSIONS: In this population, Lp(a) reductions were not significantly associated with MACE independently of LDL-C reductions. Reducing the risk of MACE by targeting Lp(a) may require greater reductions in Lp(a) with more potent therapies and/or higher initial Lp(a) levels.

Group IIA Secretory Phospholipase A2, Vascular Inflammation, and Incident Cardiovascular Disease.

Objective- Inflammation is a causal risk factor for cardiovascular disease (CVD). sPLA2-IIA (group IIA secretory phospholipase A2) plays an integral role in regulating vascular inflammation. Although studies investigated sPLA2-IIA in secondary prevention, we prospectively evaluated sPLA2-IIA mass and genetic variants with CVD events in a primary prevention population with chronic inflammation. Approach and Results- The JUPITER trial (Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin) randomized participants with LDL (low-density lipoprotein) <130 mg/dL and hsCRP (high-sensitivity C-reactive protein) ≥2 mg/L to high-intensity rosuvastatin versus placebo. Baseline and 1-year plasma sPLA2-IIA mass was measured (N=11 269 baseline; N=9620 1 year). We also identified genetic variants influencing sPLA2-IIA using genome-wide association and examined them with CVD. Three hundred thirteen incident CVD events occurred during follow-up. Baseline sPLA2-IIA mass (median, 25th-75th percentile: 3.81, 2.49-6.03 ng/mL) was associated with increased risk of CVD: risk factor-adjusted hazard ratio (95% CI; P) per SD increment: 1.22 (1.08-1.38; P=0.002). This remained significant (1.18; 1.04-1.35; P=0.01) after incrementally adjusting for hsCRP. Similar estimates were observed in rosuvastatin and placebo groups ( P treatment interaction>0.05). The rs11573156C variant in PLA2G2A (encoding sPLA2-IIA) had the strongest effect on sPLA2-II: median (25th-75th percentile, ng/mL) for CC and GG genotypes: 2.79 (1.97-4.01) and 7.38 (5.38-10.19), respectively; and had nonsignificant trend for higher CVD risk (hazard ratio, 1.11; 95% CI, 0.89-1.38; P=0.34). Conclusions- In the JUPITER population recruited on chronic inflammation, sPLA2-IIA mass was associated with CVD risk relating to vascular inflammation not fully reflected by hsCRP. Additional studies, including larger functional genetic and clinical studies, are needed to determine whether sPLA2-IIA may be a potential pharmacological target for primary prevention of CVD. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT00239681.