European Lipid Guidelines and Cardiovascular Risk Estimation: Current Status and Future Challenges.

PURPOSE OF REVIEW: Genetic, experimental, epidemiologic, and clinical data support the causal role of elevated levels of low-density lipoprotein cholesterol (LDL-C) in atherosclerosis and cardiovascular disease (CVD). The recommendations of the 2019 European guidelines are based on the concept of differential CV risk, which in turn defines the LDL-C goals that should be achieved. RECENT FINDINGS: The 2019 ESC/EAS guidelines for dyslipidaemia use the Systematic COronary Risk Evaluation (SCORE) model to assess CV risk, which provides a 10-year risk of fatal CV event. The SCORE model has recently been updated to reflect current rates of cardiovascular disease in Europe. The new SCORE2 model provides estimates of the 10-year risk of fatal and non-fatal CVD events in people aged 40-69 years, thus improving the identification of individuals at higher risk of a CVD event. However, as in the SCORE age is the main determinant of risk, young people have a relatively low estimated 10-year risk of a CV event even with high levels of one or more causal risk factors. Individuals with familial hypercholesterolaemia, who have elevated LDL-C levels from birth and have a high risk of premature CVD, are one example. The concept of cumulative LDL exposure is thus becoming increasingly important. This is also supported by Mendelian randomisation studies showing that carrying genetic variants associated with lower LDL-C levels reduces CV risk. These observations have introduced the concept of "cholesterol-years", which takes into account both LDL-C levels and time of exposure. It is crucial that future European guidelines pay more attention to this point.

How to Handle Elevated Triglycerides: Life after PROMINENT.

PURPOSE OF REVIEW: Hypertriglyceridaemia (HTG) is a common condition characterised by elevated levels of plasma triglycerides (TG), which are transported in the blood mainly by TG-rich lipoproteins (TRL). Elevated TG levels (150-400 mg/dL) are associated with increased cardiovascular risk. Severe HTG (>880 mg/dL) is associated with a risk of acute pancreatitis only. Randomised clinical trials investigating the clinical benefit of TG-lowering drugs in patients with elevated TG levels have provided conflicting results. RECENT FINDINGS: Elevated TG levels are only one marker of altered lipid/lipoprotein metabolism and indeed reflect altered concentrations of one or more classes or subfractions of TRL, which in turn may have a different association with CV risk. Fibrates, the drugs most commonly used to treat HTG, provide cardiovascular benefits to only a specific subgroup of patients. The lack of clinical benefit from pemafibrate has emphasised the concept that lowering TG levels is not sufficient to reduce the CV risk unless it is accompanied by a reduction in the number of circulating atherogenic lipoproteins, which can be assessed by determining apolipoprotein B levels. Treatment with omega-3 fatty acids was also ineffective in reducing CV risk, with the exception of icosapent ethyl, which, however, appears to have beneficial effects beyond lipids. New drugs are currently being developed that aim to lower TG levels by targeting apolipoprotein C-III or angiopoietin-like-3, both of which are involved in the metabolism of TGs. TG reduction can be achieved by various drugs, but most of them are ineffective in reducing CV risk. The results of outcome studies on new TG-lowering drugs will clarify whether lowering apoB levels is critical to achieve clinical benefit.

The burden of hypercholesterolemia and ischemic heart disease in an ageing world.

Despite a general improvement in global health conditions in the last decades, cardiovascular diseases (CVDs) are still the first global cause of death and disability worldwide, with ischemic heart disease (IHD) being responsible for half of CVD deaths. Hypercholesterolemia is a major causal risk factor for IHD. Although the availability of effective cholesterol-lowering drugs largely increased in the last few years, we are still facing disparities in the awareness of dyslipidaemia as a CVD-associated risk factor and therefore in health expenditure among different world areas. Although no significant changes have been reported globally in the levels of plasma cholesterol in the last three decades, relevant differences among world areas according to their economic status can be observed. Only high-income countries have experienced an improvement in plasma lipid profile which translated into a substantial decrease in the deaths and disabilities due to IHD, whereas countries in other income groups showed no reduction or even an increase. As expected, most of the deaths for IHD attributable to high LDL-C occur in people aged 60 years and above, although significant differences can be observed according to income. Altogether these observations suggest the need for measures to reduce the gap in treating hypercholesterolemia among income groups, with special attention to women and older people.

European guidelines for the treatment of dyslipidaemias: New concepts and future challenges.

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of mortality and morbidity worldwide. Low-density lipoprotein cholesterol (LDL-C) is one of the most important causal factors for ASCVD. Based on the evidence of the clinical benefits of lowering LDL-C, the current 2019 European Society of Cardiology (ESC) and European Atherosclerosis Society (EAS) guidelines provide guidance for optimal management of people with dyslipidaemia. These guidelines include new and revised concepts, with a general tightening of LDL-C goals to be achieved, especially for patients at high and very high cardiovascular risk, based on the results of clinical trials of the recently approved drugs for the treatment of hypercholesterolaemia. However, some issues are still open for discussion. Among others, the concept of lifetime exposure to elevated LDL-C levels will probably drive the pharmacological approach and future guidelines. In addition, other factors such as non-HDL-C, apolipoprotein B, and lipoprotein(a) are becoming increasingly important in determining cardiovascular risk. Finally, there is the question of whether combination therapy should be used as the first step to maximise the effectiveness of the pharmacological approach, avoiding the stepwise approach, which is likely to have a detrimental effect on adherence. Given the ever-changing landscape and the availability of new drugs targeting other important lipids, future guidelines will need to consider all these issues.

Neutral effect of SGLT2 inhibitors on lipoprotein metabolism: From clinical evidence to molecular mechanisms.

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are effective, well-tolerated, and safe glucose-lowering compounds for patients with type 2 diabetes mellitus (T2DM). SGLT2i benefit encompasses protection from heart and kidney failure, independently of the presence of diabetes. In addition, SGLT2i consistently reduce the risk of hospitalization for heart failure and, although with some heterogeneity between specific members of the class, favourably affect the risk of cardiovascular outcomes. The molecular mechanisms underlying the cardiovascular favourable effect are not fully clarified. Studies testing the efficacy of SGLT2i in human cohorts and experimental models of atherosclerotic cardiovascular disease (ASCVD) have reported significant differences in circulating levels and composition of lipoprotein classes. In randomized clinical trials, small but significant increases in low-density lipoprotein cholesterol (LDL-C) levels have been observed, with a still undefined clinical significance; on the other hand, favourable (although modest) effects on high-density lipoprotein cholesterol (HDL-C) and triglycerides have been reported. At the molecular level, glycosuria may promote a starving-like state that ultimately leads to a metabolic improvement through the mobilization of fatty acids from the adipose tissue and their oxidation for the production of ketone bodies. This, however, may also fuel hepatic cholesterol synthesis, thus inhibiting atherogenic lipoprotein uptake from the liver. Long-term studies collecting detailed information on lipid-lowering therapies at baseline and during the trials with SGLT2i, as well as regularly monitoring lipid profiles are warranted to disentangle the potential implications of SGLT2i in modulating lipoprotein-mediated atherosclerotic cardiovascular risk.

LDL-cholesterol control in the primary prevention of cardiovascular diseases: An expert opinion for clinicians and health professionals.

AIMS: Although adequate clinical management of patients with hypercholesterolemia without a history of known cardiovascular disease is essential for prevention, these subjects are often disregarded. Furthermore, the scientific literature on primary cardiovascular prevention is not as rich as that on secondary prevention; finally, physicians often lack adequate tools for the effective management of subjects in primary prevention and have to face some unsolved relevant issues. This document aims to discuss and review the evidence available on this topic and provide practical guidance. DATA SYNTHESIS: Available algorithms and risk charts represent the main tool for the assessment of cardiovascular risk in patients in primary prevention. The accuracy of such an estimate can be substantially improved considering the potential contribution of some additional risk factors (C-reactive protein, lipoprotein(a), family history of cardiovascular disease) and conditions (environmental pollution, sleep quality, socioeconomic status, educational level) whose impact on the cardiovascular risk has been better understood in recent years. The availability of non-invasive procedures to evaluate subclinical atherosclerosis may help to identify subjects needing an earlier intervention. Unveiling the presence of these conditions will improve cardiovascular risk estimation, granting a more appropriate intervention. CONCLUSIONS: The accurate assessment of cardiovascular risk in subjects in primary prevention with the use of algorithms and risk charts together with the evaluation of additional factors will allow physicians to approach each patient with personalized strategies, which should translate into an increased adherence to therapy and, as a consequence, a reduced cardiovascular risk.

Inclisiran: How Widely and When Should We Use It?

PURPOSE OF REVIEW: Plasma levels of LDL cholesterol (LDL-C) are causally associated with cardiovascular risk. Reducing LDL-C results in a decreased incidence of cardiovascular events, proportionally to the absolute reduction in LDL-C. The inhibition of proprotein convertase subtilisin kexin 9 (PCSK) is a highly effective and safe approach to reducing LDL-C levels. In this review, we discuss the available data on the efficacy and safety of inclisiran, a siRNA targeting PCSK9 and propose a clinical profile for the patients who can benefit the most from this approach. RECENT FINDINGS: Inclisiran is a small interfering RNA targeting the mRNA of PCSK9 specifically in the liver, owing to the conjugation with triantennary N-acetylgalactosamine. Randomized clinical trials have shown that inclisiran provides robust and durable reductions of PCSK9 and LDL-C levels, with a dosing schedule of once every 6 months after the initial and 3-month doses. These effects are consistent in different categories of patients, including patients with atherosclerotic cardiovascular disease and/or risk equivalent or patients with heterozygous familial hypercholesterolaemia. Ultimately the administration schedule may improve patients' compliance given also the favourable safety profile of the drug. Completion of ongoing outcome clinical trials will provide information on both the expected clinical benefit and the safety of inclisiran administered for longer.

LDL-Cholesterol-Lowering Therapy.

The causal relation between elevated levels of LDL-C and cardiovascular disease has been largely established by experimental and clinical studies. Thus, the reduction of LDL-C levels is a major target for the prevention of cardiovascular disease. In the last decades, statins have been used as the main therapeutic approach to lower plasma cholesterol levels; however, the presence of residual lipid-related cardiovascular risk despite maximal statin therapy raised the need to develop additional lipid-lowering drugs to be used in combination with or in alternative to statins in patients intolerant to the treatment. Several new drugs have been approved which have mechanisms of action different from statins or impact on different lipoprotein classes.

Recent insights into low-density lipoprotein metabolism and therapy.

PURPOSE OF REVIEW: Elevated levels of low-density lipoprotein cholesterol (LDL-C) are causal to atherosclerosis and, thus, the reduction of LDL-C represents a major objective for the prevention of cardiovascular disease. Aim of this review is to provide an overview on novel strategies to lower LDL-C. RECENT FINDINGS: Although inhibiting liver cholesterol biosynthesis by statins is used as the main therapeutic approach to increase hepatic LDL-receptor expression and lower plasma cholesterol levels, novel insights into lipid and lipoprotein biology have led to the development of additional lipid-lowering therapies that can be used in combination with or as an alternative to statins in patients with statin-intolerance. New approaches include bempedoic acid, proprotein convertase subtilisin/kexin type 9 inhibitors, and angiopoietin-like protein 3 inhibitors. SUMMARY: In the last decade, several novel therapeutic approaches have been tested and some of them have been approved as lipid-lowering agents. Some drugs are already available in clinical practice, whereas others are at late stages of development.

Monoclonal Antibodies in the Management of Familial Hypercholesterolemia: Focus on PCSK9 and ANGPTL3 Inhibitors.

PURPOSE OF REVIEW: Familial hypercholesterolemia (FH) is a monogenic disorder characterized by high plasma levels of low-density lipoprotein cholesterol (LDL-C) since birth and a high risk of premature cardiovascular disease. The genetic defect is carried in only one allele in heterozygous FH (HeFH) or in both in the most severe homozygous FH (HoFH). Current guidelines recommend to reduce substantially LDL-C levels in these high-risk patients, with the need to use association therapy combining agents with different mechanisms of action. As most cases of FH are attributable to mutations in the gene encoding the low-density lipoprotein receptor (LDLR), statins, even in combination with ezetimibe, are less effective in reducing LDL-C plasma levels in FH patients, who require a more intensive approach with additional lipid-lowering agents. Additional targets playing key roles in regulating LDL-C levels are represented by PCSK9 and ANGPTL3. RECENT FINDINGS: Two monoclonal antibodies (mAbs) targeting PCSK9, evolocumab and alirocumab, significantly reduce LDL-C levels in HeFH patients. In patients with HoFH, the efficacy of mAbs to PCSK9 is strictly related to the presence of a residual LDLR activity; thus, patients carrying null mutations do not respond to the therapy with these mAbs, whereas some effects can be appreciated in HoFH bearing defective mutations. Conversely, evinacumab, the mAb targeting ANGPTL3, is highly effective in reducing LDL-C levels even in HoFH patients carrying null LDLR mutations, thanks to its LDLR-independent mechanism of action. Monoclonal antibodies inhibiting PCSK9 have shown a robust effect in FH patients presenting a residual LDLR activity, while ANGPTL3 inhibitors appear to be promising even in patients carrying null LDLR mutations.

Omega n-3 Supplementation: Exploring the Cardiovascular Benefits Beyond Lipoprotein Reduction.

PURPOSE OF REVIEW: Hypertriglyceridaemia is a highly prevalent disorder worldwide. Genetic and Mendelian randomization studies have suggested that triglyceride (TG)-rich lipoproteins are causal risk factors for coronary heart disease and contribute to the residual cardiovascular risk observed in patients optimally treated with statins. However, clinical trials failed to show cardiovascular benefits of TG-lowering; in this context, trials with omega-3 fatty acids provided contrasting results. Few trials have tested the supplementation of EPA alone rather than the combination of EPA + DHA. The JELIS study showed that EPA 1.8 g/day significantly reduced CV events in hypercholesterolaemic patients given statins, an effect that was independent on lipid reduction. RECENT FINDINGS: The REDUCE-IT trial showed that high-dose (4 g/day) EPA significantly reduces the incidence of major cardiovascular events compared with placebo in patients with elevated TG levels. The clinical benefit was higher than expected by the reduction of TG-rich lipoprotein levels. Recent data support the efficacy of high-dose EPA supplementation on a background of optimal LDL-C-lowering therapy as a key approach to achieve a further and significant reduction of CV events in very-high CV risk patients with persistent hypertriglyceridaemia. The effect on lipids does not appear to fully explain the CV benefit, and additional mechanisms of action of EPA likely contribute to the cardiovascular protection, including the reduction of inflammation and platelet aggregation. Current guidelines recommend using high-dose EPA in combination with a statin in high/very-high CV risk patients with mild-to-moderate elevation of plasma TG to reduce the residual CV risk.

New Pharmacological Approaches to Target PCSK9.

PURPOSE OF REVIEW: Proprotein convertase subtilisin kexin 9 (PCSK9) plays a crucial role in regulating circulating levels of LDL-C as a consequence of its ability to inhibit LDL receptor recycling in the liver. Loss of function variants in the PCSK9 gene result in low LDL-C levels and associate with reduced cardiovascular risk, whereas gain of-function variants associate with hypercholesterolemia and increased risk of early cardiovascular events. Thus, PCSK9 inhibition has been established as an additional approach for the treatment of hypercholesterolemia. The aim of this review is to provide a brief overview of current strategies targeting PCSK9 and discuss clinical results of the emerging approaches. RECENT FINDINGS: Two monoclonal antibodies targeting circulating PCSK9 (evolocumab and alirocumab) have been approved for the treatment of hypercholesterolemia and cardiovascular disease. Later, a gene silencing approach (inclisiran), which inhibits hepatic PCSK9 synthesis, was shown to be as effective as monoclonal antibodies but with a twice a year injection and is currently under evaluation for approval. Due to the elevated costs of such therapies, several other approaches have been explored, including peptide-based anti PCSK9 vaccination, and small oral PCSK9 inhibitors, which are still in preclinical phase. In the coming years, we will assist to a progressive introduction of novel anti-PCSK9 approaches in the clinical practice for the treatment of patients with hypercholesterolemia as well as patients at high cardiovascular risk.

Cholesterol membrane content has a ubiquitous evolutionary function in immune cell activation: the role of HDL.

PURPOSE OF REVIEW: Cellular cholesterol content influences the structure and function of lipid rafts, plasma membrane microdomains essential for cell signaling and activation. HDL modulate cellular cholesterol efflux, thus limiting cholesterol accumulation and controlling immune cell activation. Aim of this review is to discuss the link between HDL and cellular cholesterol metabolism in immune cells and the therapeutic potential of targeting cholesterol removal from cell membranes. RECENT FINDINGS: The inverse relationship between HDL-cholesterol (HDL-C) levels and the risk of cardiovascular disease has been recently challenged by observations linking elevated levels of HDL-C with increased risk of all-cause mortality, infections and autoimmune diseases, paralleled by the failure of clinical trials with HDL-C-raising therapies. These findings suggest that improving HDL function might be more important than merely raising HDL-C levels. New approaches aimed at increasing the ability of HDL to remove cellular cholesterol have been assessed for their effect on immune cells, and the results have suggested that this could be a new effective approach. SUMMARY: Cholesterol removal from plasma membrane by different means affects the activity of immune cells, suggesting that approaches aimed at increasing the ability of HDL to mobilize cholesterol from cells would represent the next step in HDL biology.

Multilevel Models to Estimate Carotid Intima-Media Thickness Curves for Individual Cardiovascular Risk Evaluation.

Background and Purpose- The value of carotid intima-media thickness (cIMT)-a marker of subclinical atherosclerosis-in defining the cardiovascular risk is still debated. The aim of this study was to estimate standard cIMT progression, adjusting values over time for the main cardiovascular risk factors, in a sample of low-to-moderate cardiovascular risk subjects, to identify normative cIMT progression values. Methods- From the progression of lesions in the intima of the carotid cohort, we selected subjects who underwent 4 planned serial clinical evaluations and ultrasound cIMT determinations, on average every 4 years. Subject taking glucose-lowering therapies in secondary cardiovascular prevention or with cardiovascular risk score >5 were excluded from the analysis. The growth of cIMT across the study period (12 years) was assessed by use of individual growth curve modeling within multilevel models. Results- A total of 1175 (36% men; mean age, 53±11 years at baseline) participants at low/intermediate cardiovascular risk have been included in this analysis. A significant and marked slope of the mean and maximum cIMT growth curves (ß=0.009 and ß=0.012, respectively) was observed, confirming that it is a function of age. A stratified analysis by decades of age highlighted a nonlinear cIMT progression over time. In addition, different patterns of cIMT development between sex were observed. Finally, different slopes in mean and maximum cIMT curves, with a significant spread since the fifth decade, were observed in the cIMT growth curve models of subjects developing multifocal carotid atherosclerosis compared with the rest of the population. Conclusions- These findings proved that the rate of change in cIMT over time is a sign of the development of atherosclerosis, which cannot be a priori assumed linear. These data, therefore, support the clinical relevance of these growth curve models for cIMT progression to be considered as useful tool to identify subjects with faster atherosclerosis progression and thus at increased cardiovascular risk.

Cardiovascular events with PCSK9 inhibitors: an updated meta-analysis of randomised controlled trials.

The therapy with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors efficiently reduces plasma cholesterol levels, which has been recently associated with improvement in cardiovascular outcomes. This meta-analysis aimed at investigating the safety and efficacy of treatment with the clinically available anti-PCSK9 monoclonal antibodies (mAbs) in all published randomized clinical trials (RCTs), updating the available results with the recently published ODYSSEY OUTCOMES trial. Data search was carried out using PubMed/MEDLINE and EMBASE (inception - January 2019). Inclusion criteria were: (1) phase 2 or 3 RCTs; (2) comparing anti-PCSK9 mAbs (specifically evolocumab and alirocumab) with placebo; (3) with effects on outcomes reported; (4) with treatment duration longer than 8 weeks. Odds ratios (ORs) with 95% CIs were used as summary statistics. We pooled the estimates by using both the DerSimonian & Laird method (random-effects model). Between-study heterogeneity was tested by Cochrane's Q test and measured with the I2 statistics. Twenty-eight RCTs comprising 62,281 participants (33,204 in the mAb arm, 29,077 in the placebo arm) were included in the meta-analysis. The treatment follow-up ranged from 8 weeks up to 208 weeks. Overall, no significant difference in all-cause mortality was observed between the two groups (OR 0.93 [95% CI, 0.85-1.03]). The treatment with an anti-PCSK9 mAb was associated with a significant reduction of CV events compared with placebo (OR 0.83 [95% CI, 0.78-0.87]), being the FOURIER and ODYSSEY OUTCOMES studies the major contributors. Both myocardial infarction and stroke were significantly reduced following the treatment with an anti-PCSK9 mAb. No significant difference was observed in cardiovascular mortality (OR 0.94 [95% CI, 0.83-1.07]). The incidence of serious adverse events was similar in the two groups (OR: 0.95, [95% CI, 0.91-0.99]). Thus, the pharmacological approach with anti-PCSK9 mAbs significantly and safely improves cardiovascular outcomes. Despite that, the pooled analysis failed to show a significant cardiovascular mortality benefit with anti-PCSK9 mAb treatment, suggesting that specific longer-term studies are warranted to address this issue. We suggest that the observed delay between the rapid effect on plasma cholesterol levels and the emergence of the clinical benefit, observed both in FOURIER and ODYSSEY OUTCOMES trials, might explain this finding.

The Interplay of Lipids, Lipoproteins, and Immunity in Atherosclerosis.

PURPOSE OF REVIEW: Atherosclerosis is an inflammatory disorder of the arterial wall, in which several players contribute to the onset and progression of the disease. Besides the well-established role of lipids, specifically cholesterol, and immune cell activation, new insights on the molecular mechanisms underlying the atherogenic process have emerged. RECENT FINDINGS: Meta-inflammation, a condition of low-grade immune response caused by metabolic dysregulation, immunological memory of innate immune cells (referred to as "trained immunity"), cholesterol homeostasis in dendritic cells, and immunometabolism, i.e., the interplay between immunological and metabolic processes, have all emerged as new actors during atherogenesis. These observations reinforced the interest in directly targeting inflammation to reduce cardiovascular disease. The novel acquisitions in pathophysiology of atherosclerosis reinforce the tight link between lipids, inflammation, and immune response, and support the benefit of targeting LDL-C as well as inflammation to decrease the CVD burden. How this will translate into the clinic will depend on the balance between costs (monoclonal antibodies either to PCSK9 or to IL-1ß), side effects (increased incidence of death due to infections for anti-IL-1ß antibody), and the benefits for patients at high CVD risk.

Strategies for the use of nonstatin therapies.

PURPOSE OF REVIEW: Dyslipidaemias are a major risk factor for cardiovascular disease (CVD); in particular, high levels of low-density lipoprotein cholesterol (LDL-C) have been associated to a higher cardiovascular risk. Reducing LDL-C levels decreases the risk of coronary heart disease (CHD), and the greater the LDL-C reduction, the greater the decrease in cardiovascular risk. Although statins represent the first line lipid-lowering therapy, many patients do not reach the recommended goals or exhibit adverse side effects leading to therapy discontinuation; in addition, a significant percentage of statin-treated patients continue to experience cardiovascular events even in the presence of well controlled LDL-C levels, because of alterations in other lipid/lipoprotein classes, including triglycerides and high-density lipoprotein cholesterol. RECENT FINDINGS: These conditions require further therapeutic interventions to achieve the recommended lipid goals. Several drugs have been developed to address these needs. Recent studies have shown that the association of ezetimibe with rosuvastatin or atorvastatin results in a better hypolipidaemic effect; in addition to this, PCSK9 inhibitors significantly reduce LDL-C levels and cardiovascular events. SUMMARY: For patients who are intolerant to statins or not able to reach the recommended LDL-C levels, despite maximal tolerated dose of statin, or exhibiting additional lipid alterations, several drugs are available that can be used either in monotherapy or on top of the maximally tolerated dose of statins.