Is Targeting LDL-C Levels Below 70 mg/dL Beneficial for Cardiovascular and Overall Health? A Critical Examination of the Evidence

Over the past two decades, cardiovascular disease (CVD) prevention guidelines have progressively lowered LDL-C targets to <70 mg/dL for high-risk individuals based on the assumption of a linear relationship between LDL-C levels and CVD risk. However, the available evidence challenges this premise. Multiple studies demonstrate a weak or inconsistent association between LDL-C levels and atherosclerosis progression at the individual patient-level. Systematic reviews supporting the linearity assumption have notable limitations, including extrapolation beyond observed LDL-C ranges and potential ecological fallacy, as meta-regression analyses rely on study-level data, while patient-level data within the same trials often show no association between LDL-C reduction and CVD outcomes. Moreover, randomized controlled trials explicitly designed to assess LDL-C targets have yielded inconclusive and biased results. LDL-C itself is a heterogeneous marker, with particle size and composition influencing its atherogenicity. The cardiovascular benefits of lipid-lowering therapies may arise in part from pleiotropic effects unrelated to LDL-C lowering. Additionally, several studies indicate that higher LDL-C levels are paradoxically associated with longevity in elderly populations that is equal to or even greater than that of the general population. Collectively, this body of evidence raises questions about the validity of current LDL-C targets < 70 mg/dL in high-risk patients.

Therapeutic PCSK9 targeting: Inside versus outside the hepatocyte?

As a major regulator of LDL receptor (LDLR) activity and thus of LDL-cholesterol (LDL-C) levels, proprotein convertase subtilisin/kexin type 9 (PCSK9) represents an obvious therapeutic target for lipid lowering. The PCSK9 inhibitors, alirocumab and evolocumab, are human monoclonal antibodies (mAbs) that act outside the cell by complexing circulating PCSK9 and thus preventing its binding to the LDLR. In contrast, inclisiran, a small interfering RNA (siRNA), inhibits hepatic synthesis of PCSK9, thereby resulting in reduced amounts of the protein inside and outside the cell. Both approaches result in decreased plasma LDL-C concentrations and improved cardiovascular outcomes. Marginally superior LDL-C reduction (≈ 60 %) is achieved with mAbs as compared to the siRNA (≈ 50 %); head-to-head comparisons are required to confirm between-class differences in efficacy. Both drug classes have shown variability in LDL-C lowering response between individuals in waterfall analyses. Whereas mAb-mediated inhibition leads to a compensatory increase in plasma PCSK9 levels, siRNA treatment reduces them. These agents differ in their pharmacokinetic and pharmacodynamic features, which may translate into distinct clinical opportunities under acute (e.g. acute coronary syndromes) as compared to chronic conditions. Both drug classes provide additional reduction in LDL-C levels (up to 50 %) beyond those achieved with statin therapy, facilitating attainment of guideline-recommended LDL-C goals in high and very high-risk patients. Additional PCSK9 inhibitors, including an oral macrocyclic peptide, a small PCSK9 binding protein and a novel small molecule, plus hepatic gene editing of PCSK9, are under development. This review critically appraises pharmacological strategies to target PCSK9 either inside or outside the cell.

Pharmacological regression of atherosclerotic plaque in patients with type 2 diabetes

Atherosclerosis of the coronary arteries continues to be one of the major global health burdens and acute coronary syndrome is responsible annually for at least 30 % of all deaths globally. Acute coronary syndrome may be the consequence of thrombus formation after erosion or rupture of obstructive or non-obstructive atherosclerotic plaque. The rupture of plaques is mostly caused by mechanical stress usually called cap fatigue. Vulnerable plaques are characterized by a softer atheromatous core and a thinner fibrous cap, with inflammation and hypercholesterolemia playing a crucial role in the atherothrombotic process. Based on animal studies that extend back to the 1920s, regression of atherosclerotic plaques in humans has just started to be considered and pursued. The idea that the human atherosclerotic plaques could regress at all met an important resistance over the decades; indeed, advanced plaques contain components, such as necrosis, calcification and fibrosis, which are hard to be removed. However, new animal models and imaging technics allowed a more complete and accurate quantitative assessment of plaque volume and are shedding new light on atherosclerosis regression. In this review, we are revisiting the existence of atherosclerosis regression in preclinical and clinical studies, with a focus on the latest mechanistic insights and on the newest pharmacological agents, particularly in patients with diabetes. Interestingly, we suggested that based on literature insights and preclinical studies, a combination of drugs to target hyperglycemia, dyslipidemia and inflammation may be desirable for a fast-track Pharmacological regression of atherosclerotic plaque in patients with type 2 diabetes.

Achieving More Optimal Lipid Control with Non-Statin Lipid Lowering Therapy

PURPOSE OF REVIEW

The use of statins has transformed approaches to the prevention of cardiovascular disease. However, many patients remain at a major risk of experiencing cardiovascular events, due to a range of factors including suboptimal control of low-density lipoprotein cholesterol (LDL-C). Accordingly, there is an ongoing need to develop additional strategies, beyond the use of statins, to achieve more effective reductions in cardiovascular risk.

RECENT FINDINGS

Genomic studies have implicated the causal role of LDL in atherosclerosis and identified that polymorphisms influencing factors involved in lipid metabolism influence both the level of LDL-C and cardiovascular risk. These findings have highlighted the potential for cardiovascular benefit from development of therapies targeting these factors and incremental benefit when used in combination with statins. Clinical trials have demonstrated that these new agents have favourable effects on both atherosclerotic plaque and cardiovascular events. Additional work has sought to improve intensification of statin therapy and adherence with lipid lowering therapy, to achieve more effective cardiovascular prevention via lipid lowering. Emerging therapies, beyond statins, have the potential to optimise lipid levels and play an effective role in the prevention of cardiovascular disease.

Statin use is associated with less ST-elevation versus non-ST-elevation myocardial infarction in a nationwide study

BACKGROUND AND AIMS

Statin therapy reduces myocardial infarction rate but whether it is associated with a shift of ST-elevation myocardial infarction (STEMI) towards non-ST-elevation myocardial infarction (non-STEMI) remains unknown. Thus, we tested the hypothesis that statin use is associated with less STEMI relative to non-STEMI in first-time myocardial infarction.

METHODS

In a nationwide study, including 66,896 patients with first-time myocardial infarction between 2010 and 2021, we obtained multivariable risk estimates for STEMI versus non-STEMI according to any statin use, cumulated statin use, and daily statin dose. Furthermore, we obtained hazard ratios for 60-day mortality (5545 deaths) following myocardial infarction according to type of infarction.

RESULTS

Odds ratios for STEMI versus non-STEMI were 0.81 (95 % CI:0.77-0.85) and 1.07 (1.01-1.13) in current and previous statin users compared to never statin users. Cumulated statin exposure yielded odds ratios of 0.96 (0.87-1.07) for <2 statin-years, 0.87 (0.79-0.95) for 2-4.9 statin-years, 0.80 (0.74-0.87) for 5-10 statin-years, and 0.75 (0.70-0.80) for >10 statin-years compared to never users. Corresponding odds ratios for statin dose intensity were 0.89 (0.84-0.95) for low-intensity, 0.77 (0.73-0.82) for moderate-intensity, and 0.70 (0.63-0.77) for high-intensity. Results were similar in multiple sensitivity analyses and using a cohort design. The hazard ratio for 60-day mortality after first-time STEMI versus non-STEMI was 2.24 (2.13-2.37).

CONCLUSIONS

In this nationwide study, prior statin use is associated with less STEMI relative to non-STEMI in a dose dependent manner. This indicates that statin therapy, in addition to reducing myocardial infarction event rates, also result in a less severe presentation of myocardial infarctions.

Plaque Stabilization and Regression, from Mechanisms to Surveillance and Clinical Strategies

With advances in therapies to reduce cardiovascular events and improvements in coronary imaging, an increasing number of clinical trials have demonstrated that treatments to reduce cardiovascular events in coronary artery disease are associated with favorable effects on atherosclerotic plaque size and characteristics. It has been observed that various drugs may induce plaque regression and enhance plaque stability after plaque formation. Numerous clinical trials have been conducted to verify the occurrence of plaque stabilization and regression and their beneficial effects on cardiovascular events. Using invasive imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT), researchers have been able to gather evidence supporting the existence of coronary plaque stabilization and regression. In this review, we explore the possible mechanisms of plaque stabilization and regression, summarize the imaging features of plaque stabilization and regression, and assemble the evidence from clinical studies that have used different features as observational endpoints.

The Imperative to Enhance Cost-Effectiveness for Cardiovascular Therapeutic Development

Cardiovascular disease (CVD) is the leading cause of mortality worldwide. Therapeutic agents, such as those that lower low-density lipoprotein cholesterol, have been a critical factor in mitigating CVD event risk and demonstrate the important role that drug discovery plays in reducing morbidity and mortality. However, rapidly rising development costs, diminishing returns, and an increasingly challenging regulatory environment have all contributed to a declining number of cardiovascular (CV) therapeutic agents entering the health care marketplace. For pharmaceutical companies, a traditional cardiovascular outcomes trial (CVOT) can be a major financial burden and impediment to CV agent development. They can take as long as a decade to conduct, delaying potential investment return while carrying risk of failure. For patients, lengthy CVOTs delay drug accessibility. Without cost-effective CVOTs, drug innovation may be compromised, with CV patients bearing the consequences. This paper reviews potential approaches for making CV drug development more cost-effective.

Atherosclerotic Plaque Erosion: Mechanisms, Clinical Implications, and Potential Therapeutic Strategies-A Review

Atherosclerosis is an insidious and progressive inflammatory disease characterized by the formation of lipid-laden plaques within the intima of arterial walls with potentially devastating consequences. While rupture of vulnerable plaques has been extensively studied, a distinct mechanism known as plaque erosion (PE) has gained recognition and attention in recent years. PE, characterized by the loss of endothelial cell lining in the presence of intact fibrous cap, contributes to a significant and growing proportion of acute coronary events. However, despite a heterogeneous substrate underlying coronary thrombosis, treatment remains identical. This article provides an overview of atherosclerotic PE characteristics and its underlying mechanisms, highlights its clinical implications, and discusses potential therapeutic strategies.

Role of Lipid-Lowering and Anti-Inflammatory Therapies on Plaque Stabilization

Atherosclerosis is the predominant underlying etiopathology of coronary artery disease. Changes in plaque phenotype from stable to high risk may spur future major adverse cardiac events (MACE). Different pharmacological therapies have been implemented to mitigate this risk. Over the last two decades, intravascular imaging modalities have emerged in clinical studies to clarify how these therapies may affect the composition and burden of coronary plaques. Lipid-lowering agents, such as statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 inhibitors, were shown not only to reduce low-density lipoprotein levels and MACE but also to directly affect features of coronary plaque vulnerability. Studies have demonstrated that lipid-lowering therapy reduces the percentage of atheroma volume and number of macrophages and increases fibrous cap thickness. Future studies should answer the question of whether pharmacological plaque stabilization may be sufficient to mitigate the risk of MACE for selected groups of patients with atherosclerotic coronary disease.

New targets and mechanisms of action for lipid-lowering and anti-inflammatory therapies in atherosclerosis: where does the field stand?

INTRODUCTION

Atherosclerotic cardiovascular disease remains a leading cause of morbidity and mortality worldwide, despite widespread use of statins. There is a need to develop additional therapeutic strategies that will complement statins to achieve more effective reductions in cardiovascular risk.

AREAS COVERED

This review provides a comprehensive summary of current areas of therapeutic development targeting both lipid and inflammatory factors implicated in the pathogenesis of atherosclerosis. In addition to develop of novel approaches that will produce more effective lowering of low-density lipoprotein cholesterol, clinical trials are currently evaluating the potential to target other atherogenic lipid parameters such as triglyceride-rich lipoproteins and Lp(a), in addition to promoting the biological properties of high-density lipoproteins. Targeting inflammation within the vascular wall has emerged as a new frontier in cardiovascular prevention, with early evidence that use of anti-inflammatory agents have the potential to reduce cardiovascular risk.

EXPERT OPINION

Clinical practice has an increasing array of therapeutic tools to achieve more effective lowering of low-density lipoprotein cholesterol for high-risk patients. In addition, clinical trials have the potential to deliver a range of additional agents to the clinic, that target alternative lipid and inflammatory mediators. This will permit the potential to personalize cardiovascular prevention.

A Practical Approach to the Management of Residual Cardiovascular Risk: United Arab Emirates Expert Consensus Panel on the Evidence for Icosapent Ethyl and Omega-3 Fatty Acids

PURPOSE

Patients with hyperlipidemia treated with statins remain at a residual cardiovascular (CV) risk. Omega-3 polyunsaturated fatty acids hold the potential to mitigate the residual CV risk in statin-treated patients, with persistently elevated triglyceride (TG) levels.

METHOD

We reviewed the current evidence on the use of icosapent ethyl (IPE), an omega-3 fatty acid yielding a pure form of eicosapentaenoic acid.

RESULTS

REDUCE-IT reported a significant 25% reduction in CV events, including the need for coronary revascularization, the risk of fatal/nonfatal myocardial infarction, stroke, hospitalization for unstable angina, and CV death in patients on IPE, unseen with other omega-3 fatty acids treatments. IPE was effective in all patients regardless of baseline CV risk enhancers (TG levels, type-2 diabetes status, weight status, prior revascularization, or renal function). Adverse events (atrial fibrillation/flutter) related to IPE have occurred mostly in patients with prior atrial fibrillation. Yet, the net clinical benefit largely exceeded potential risks. The combination with other omega-3 polyunsaturated fatty acids, in particular DHA, eliminated the effect of EPA alone, as reported in the STRENGTH and OMEMI trials. Adding IPE to statin treatment seems to be cost-effective, especially in the context of secondary prevention of CVD, decreasing CV event frequency and subsequently the use of healthcare resources.

CONCLUSION

Importantly, IPE has been endorsed by 20 international medical societies as a statin add-on treatment in patients with dyslipidemia and high CV risk. Robust medical evidence supports IPE as a pillar in the management of dyslipidemia.

Characteristics of Coronary Atherosclerosis Related to Plaque Burden Regression During Treatment With Alirocumab: The ARCHITECT Study

BACKGROUND

Intensive lipid-lowering therapy may induce coronary atherosclerosis regression. Nevertheless, the factors underlying the effect of lipid-lowering therapy on disease regression remain poorly characterized. Our aim was to determine which characteristics of atherosclerotic plaque are associated with a greater reduction in coronary plaque burden (PB) after treatment with alirocumab in patients with familial hypercholesterolemia.

METHODS

The ARCHITECT study (Effect of Alirocumab on Atherosclerotic Plaque Volume, Architecture and Composition) is a phase IV, open-label, multicenter, single-arm clinical trial to assess the effect of the treatment with alirocumab for 78 weeks on the coronary atherosclerotic PB and its characteristics in subjects with familial hypercholesterolemia without clinical atherosclerotic cardiovascular disease. Participants underwent a coronary computed tomographic angiography at baseline and a final one at 78 weeks. Every patient received alirocumab 150 mg subcutaneously every 14 days in addition to high-intensity statin therapy.

RESULTS

One hundred and four patients were enrolled. Median age was 53.3 (46.2-59.4) years and 54 were women (51.9%). The global coronary PB changed from 34.6% (32.5%-36.8%) at entry to 30.4% (27.4%-33.4%) at follow-up, which is -4.6% (-7.7% to -1.9%; P<0.001) reduction. A decrease in the percentage of unstable core (fibro-fatty+necrotic plaque; from 14.1 [7.9-22.3] to 8.0 [6.4-10.6]; -6.6%; P<0.001) was found. A greater PB (β, 0.36 [0.13-0.59]; P=0.002) and a higher proportion of unstable core (β, 0.15 [0.08-0.22]; P<0.001) were significantly related to PB regression.

CONCLUSIONS

Treatment with alirocumab in addition to high-intensity statin therapy might produce a greater PB regression in patients with familial hypercholesterolemia with higher baseline PB and in those with larger unstable core. Further studies are needed to corroborate the hypothesis raised by these results.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05465278.

Impact of PCSK9 inhibitors on coronary atheroma phenotype following myocardial infarction: insights from intravascular imaging

PURPOSE OF REVIEW

The aim of this study was to review the impact of combination lipid lowering with statins and proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors on coronary atherosclerosis using serial intravascular imaging.

RECENT FINDINGS

Early studies using intravascular ultrasound established the ability of increasingly intensive lipid lowering to both slow progression and ultimately promote regression of coronary disease. More recent clinical trials that have employed serial imaging with optical coherence tomography have permitted the ability to evaluate the impact of intensive lipid lowering on compositional features associated with plaque vulnerability. In particular, the combination of intensive statin and PCSK9 inhibitor therapy promotes plaque stability in patients following an acute coronary syndrome.

SUMMARY

More intensive lipid lowering using the combination of statins and PCSK9 inhibitors promote plaque regression in addition to promoting calcification, fibrous cap thickening and reductions in plaque lipid. These plaque-stabilizing effects underscore the benefits of combination therapy on cardiovascular events and highlight the importance of combination lipid-lowering therapy.

Atherosclerotic Coronary Plaque Regression and Risk of Adverse Cardiovascular Events: A Systematic Review and Updated Meta-Regression Analysis

Importance

The association between changes in atherosclerotic plaque induced by lipid-lowering therapies (LLTs) and reduction in major adverse cardiovascular events (MACEs) remains controversial.

Objective

To evaluate the association between coronary plaque regression assessed by intravascular ultrasound (IVUS) and MACEs.

Data Sources

A comprehensive, systematic search of publications in PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science was performed.

Study Selection

Clinical prospective studies of LLTs reporting change in percent atheroma volume (PAV) assessed by IVUS and describing MACE components were selected.

Data Extraction and Synthesis

Reporting was performed in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The association between mean change in PAV and MACEs was analyzed by meta-regression using mixed-effects, 2-level binomial logistic regression models, unadjusted and adjusted for clinical covariates, including mean age, baseline PAV, baseline low-density lipoprotein cholesterol level, and study duration.

Main Outcome and Measures

Mean PAV change and MACE in intervention and comparator arms were assessed in an updated systematic review and meta-regression analysis of IVUS trials of LLTs that also reported MACEs.

Results

This meta-analysis included 23 studies published between July 2001 and July 2022, including 7407 patients and trial durations ranging from 11 to 104 weeks. Mean (SD) patient age ranged from 55.8 (9.8) to 70.2 (7.6) years, and the number of male patients from 245 of 507 (48.3%) to 24 of 26 (92.3%). Change in PAV across 46 study arms ranged from -5.6% to 3.1%. The number of MACEs ranged from 0 to 72 per study arm (17 groups [37%] reported no events, 9 [20%] reported 1-2 events, and 20 [43%] reported ≥3 events). In unadjusted analysis, a 1% decrease in mean PAV was associated with 17% reduced odds of MACEs (unadjusted OR, 0.83; 95% CI, 0.71-0.98; P = .03), and with a 14% reduction in MACEs in adjusted analysis (adjusted OR, 0.86; 95% CI, 0.75-1.00; P = .050). Further adjustment for cardiovascular risk factors showed a 19% reduced risk (adjusted OR, 0.81; 95% CI, 0.68-0.96; P = .01) per 1% decrease in PAV. A 1% reduction of PAV change between intervention and comparator arms within studies was also associated with a significant 25% reduction in MACEs (OR, 0.75; 95% CI, 0.56-1.00; P = .046).

Conclusions and Relevance

In this meta-analysis, regression of atherosclerotic plaque by 1% was associated with a 25% reduction in the odds of MACEs. These findings suggest that change in PAV could be a surrogate marker for MACEs, but given the heterogeneity in the outcomes, additional data are needed.

Lipid-Associated GWAS Loci Predict Antiatherogenic Effects of Rosuvastatin in Patients with Coronary Artery Disease

We have shown that lipid-associated loci discovered by genome-wide association studies (GWAS) have pleiotropic effects on lipid metabolism, carotid intima-media thickness (CIMT), and CAD risk. Here, we investigated the impact of lipid-associated GWAS loci on the efficacy of rosuvastatin therapy in terms of changes in plasma lipid levels and CIMT. The study comprised 116 CAD patients with hypercholesterolemia. CIMT, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) were measured at baseline and after 6 and 12 months of follow-up, respectively. Genotyping of fifteen lipid-associated GWAS loci was performed by the MassArray-4 System. Linear regression analysis adjusted for sex, age, body mass index, and rosuvastatin dose was used to estimate the phenotypic effects of polymorphisms, and p-values were calculated through adaptive permutation tests by the PLINK software, v1.9. Over one-year rosuvastatin therapy, a decrease in CIMT was linked to rs1689800, rs4846914, rs12328675, rs55730499, rs9987289, rs11220463, rs16942887, and rs881844 polymorphisms (Pperm < 0.05). TC change was associated with rs55730499, rs11220463, and rs6065906; LDL-C change was linked to the rs55730499, rs1689800, and rs16942887 polymorphisms; and TG change was linked to polymorphisms rs838880 and rs1883025 (Pperm < 0.05). In conclusion, polymorphisms rs1689800, rs55730499, rs11220463, and rs16942887 were found to be predictive markers for multiple antiatherogenic effects of rosuvastatin in CAD patients.

Novel ultrasound techniques in the identification of vulnerable plaques-an updated review of the literature

Atherosclerosis is an inflammatory disease partly mediated by lipoproteins. The rupture of vulnerable atherosclerotic plaques and thrombosis are major contributors to the development of acute cardiovascular events. Despite various advances in the treatment of atherosclerosis, there has been no satisfaction in the prevention and assessment of atherosclerotic vascular disease. The identification and classification of vulnerable plaques at an early stage as well as research of new treatments remain a challenge and the ultimate goal in the management of atherosclerosis and cardiovascular disease. The specific morphological features of vulnerable plaques, including intraplaque hemorrhage, large lipid necrotic cores, thin fibrous caps, inflammation, and neovascularisation, make it possible to identify and characterize plaques with a variety of invasive and non-invasive imaging techniques. Notably, the development of novel ultrasound techniques has introduced the traditional assessment of plaque echogenicity and luminal stenosis to a deeper assessment of plaque composition and the molecular field. This review will discuss the advantages and limitations of five currently available ultrasound imaging modalities for assessing plaque vulnerability, based on the biological characteristics of the vulnerable plaque, and their value in terms of clinical diagnosis, prognosis, and treatment efficacy assessment.

Alirocumab and Coronary Atherosclerosis in Asymptomatic Patients with Familial Hypercholesterolemia: The ARCHITECT Study

BACKGROUND

The effect of alirocumab, a PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor, on coronary plaque burden in patients with familial hypercholesterolemia has not been addressed. Our aim was to assess changes in coronary plaque burden and its characteristics after treatment with alirocumab by quantification and characterization of atherosclerotic plaque throughout the coronary tree on the basis of a noninvasive analysis of coronary computed tomographic angiography in asymptomatic subjects with familial hypercholesterolemia receiving optimized and stable treatment with maximum tolerated statin dose with or without ezetimibe.

METHODS

This study is a phase IV, open-label, multicenter, single-arm clinical trial to assess changes in coronary plaque burden and its characteristics after 78 weeks of treatment with alirocumab in patients with familial hypercholesterolemia without clinical atherosclerotic cardiovascular disease. Participants underwent an initial coronary computed tomographic angiography at baseline and another at 78 weeks. Every patient received 150 mg of alirocumab subcutaneiously every 14 days in addition to high-intensity statin therapy. The main outcome was the change on coronary plaque burden and its characteristics by quantification and characterization of atherosclerotic plaque throughout the coronary tree on the basis of analysis of coronary computed tomographic angiography.

RESULTS

The study was completed by 104 patients. The median age was 53.3 (46.2-59.4) years. Of these patients, 54 were women (51.9%). Median low-density lipoprotein cholesterol was 138.9 (117.5-175.3) mg/dL at entry and 45.0 (36.0-65.0) mg/dL at follow-up (P<0.001). Coronary plaque burden changed from 34.6% (32.5%-36.8%) at entry to 30.4% (27.4%-33.4%) at follow-up (P<0.001). A significant change in the characteristics of the coronary atherosclerosis was also found: an increase in the proportion of calcified (+0.3%; P<0.001) and mainly fibrous (+6.2%; P<0.001) plaque, accompanied by a decrease in the percentage of fibro-fatty (-3.9%; P<0.001) and necrotic plaque (-0.6%; P<0.001).

CONCLUSIONS

Treatment with alirocumab in addition to high-intensity statin therapy resulted in significant regression of coronary plaque burden and plaque stabilization on coronary computed tomographic angiography over 78 weeks in these groups of patients with familial hypercholesterolemia without clinical atherosclerotic cardiovascular disease. ARCHITECT (Effect of Alirocumab on Atherosclerotic Plaque Volume, Architecture and Composition) could link and explain ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) results.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05465278.

Intravascular imaging assessment of pharmacotherapies targeting atherosclerosis: advantages and limitations in predicting their prognostic implications

Intravascular imaging has been often used over the recent years to examine the efficacy of emerging therapies targeting plaque evolution. Serial intravascular ultrasound, optical coherence tomography, or near-infrared spectroscopy-intravascular ultrasound studies have allowed us to evaluate the effects of different therapies on plaque burden and morphology, providing unique mechanistic insights about the mode of action of these treatments. Plaque burden reduction, a decrease in necrotic core component or macrophage accumulation-which has been associated with inflammation-and an increase in fibrous cap thickness over fibroatheromas have been used as surrogate endpoints to assess the value of several drugs in inhibiting plaque evolution and improving clinical outcomes. However, some reports have demonstrated weak associations between the effects of novel treatments on coronary atheroma and composition and their prognostic implications. This review examines the value of invasive imaging in assessing pharmacotherapies targeting atherosclerosis. It summarizes the findings of serial intravascular imaging studies assessing the effects of different drugs on atheroma burden and morphology and compares them with the results of large-scale trials evaluating their impact on clinical outcome. Furthermore, it highlights the limited efficacy of established intravascular imaging surrogate endpoints in predicting the prognostic value of these pharmacotherapies and introduces alternative imaging endpoints based on multimodality/hybrid intravascular imaging that may enable more accurate assessment of the athero-protective and prognostic effects of emerging therapies.

An Expert Opinion on the Role of the Rosuvastatin/Amlodipine Single Pill Fixed Dose Combination in Cardiovascular Prevention

Current cardiovascular disease prevention strategies are based on the management of cardiovascular risk as a continuum, redefining the therapeutic goals for each individual based on the estimated global risk profile. Given the frequent clustering of the principal cardiovascular risk factors, such as hypertension, diabetes and dyslipidaemia, in the same individual, patients are required to take multiple drugs to achieve therapeutic targets. The adoption of single pill fixed dose combinations may contribute to achieve better control of blood pressure and cholesterol compared to the separate administration of the individual drugs, mostly due to better adherence related to therapeutic simplicities. This paper reports the outcomes of an Expert multidisciplinary Roundtable. In particular, the rational and potential clinical use of the single pill fixed dose combination "Rosuvastatin-Amlodipine" for the management of concomitant hypertension/hypercholesterolemia in different clinical fields are discussed. This Expert Opinion also illustrates the importance of an early and effective management of total cardiovascular risk, highlights the substantial benefits of combining blood pressure and lipid-lowering treatments in a single-pill fixed dose combination and attempts to identify and overcome the barriers to the implementation in clinical practice of the fixed dose combinations with dual targets. This Expert Panel identifies and proposes the categories of patients who may benefit the most from this fixed dose combination.

Impact of lipid lowering on coronary atherosclerosis moving from the lumen to the artery wall

Randomized clinical trials have demonstrated that increasingly intensive lowering of low-density lipoprotein cholesterol (LDL-C) reduces the rate of cardiovascular events in the primary and secondary prevention setting. Integration of serial coronary imaging within clinical trials has enabled evaluation of medical therapies on the natural history of coronary disease. These studies have extended from early investigation of coronary obstruction with angiography to more contemporary evaluation of plaque burden and composition with imaging modalities that directly visualize the artery wall. The findings of these trials have demonstrated that intensive lipid lowering promotes plaque regression and stabilization. The lessons of this body of research provide a biological rationale underscoring the ability of intensive lipid lowering to reduce cardiovascular risk and have the potential to promote greater uptake in clinical practice.

ANGPTL4 stabilizes atherosclerotic plaques and modulates the phenotypic transition of vascular smooth muscle cells through KLF4 downregulation

Atherosclerosis, the leading cause of death, is a vascular disease of chronic inflammation. We recently showed that angiopoietin-like 4 (ANGPTL4) promotes cardiac repair by suppressing pathological inflammation. Given the fundamental contribution of inflammation to atherosclerosis, we assessed the role of ANGPTL4 in the development of atherosclerosis and determined whether ANGPTL4 regulates atherosclerotic plaque stability. We injected ANGPTL4 protein twice a week into atherosclerotic Apoe-/- mice and analyzed the atherosclerotic lesion size, inflammation, and plaque stability. In atherosclerotic mice, ANGPTL4 reduced atherosclerotic plaque size and vascular inflammation. In the atherosclerotic lesions and fibrous caps, the number of α-SMA(+), SM22α(+), and SM-MHC(+) cells was higher, while the number of CD68(+) and Mac2(+) cells was lower in the ANGPTL4 group. Most importantly, the fibrous cap was significantly thicker in the ANGPTL4 group than in the control group. Smooth muscle cells (SMCs) isolated from atherosclerotic aortas showed significantly increased expression of CD68 and Krüppel-like factor 4 (KLF4), a modulator of the vascular SMC phenotype, along with downregulation of α-SMA, and these changes were attenuated by ANGPTL4 treatment. Furthermore, ANGPTL4 reduced TNFα-induced NADPH oxidase 1 (NOX1), a major source of reactive oxygen species, resulting in the attenuation of KLF4-mediated SMC phenotypic changes. We showed that acute myocardial infarction (AMI) patients with higher levels of ANGPTL4 had fewer vascular events than AMI patients with lower levels of ANGPTL4 (p < 0.05). Our results reveal that ANGPTL4 treatment inhibits atherogenesis and suggest that targeting vascular stability and inflammation may serve as a novel therapeutic strategy to prevent and treat atherosclerosis. Even more importantly, ANGPTL4 treatment inhibited the phenotypic changes of SMCs into macrophage-like cells by downregulating NOX1 activation of KLF4, leading to the formation of more stable plaques.

Intracoronary Imaging of Vulnerable Plaque-From Clinical Research to Everyday Practice

The introduction into clinical practice of intravascular imaging, including intravascular ultrasound (IVUS), optical coherence tomography (OCT) and their derivatives, allowed for the in vivo assessment of coronary atherosclerosis in humans, including insights into plaque evolution and progression process. Intravascular ultrasound, the most commonly used intravascular modality in many countries, due to its low resolution cannot assess many features of vulnerable plaque such as lipid plaque or thin-cap fibroatheroma. Thus, novel methods were introduced to facilitate this problem including virtual histology intravascular ultrasound and later on near-infrared spectroscopy and OCT. Howbeit, none of the currently used modalities can assess all known characteristics of plaque vulnerability; hence, the idea of combining different intravascular imaging methods has emerged including NIRS-IVUS or OCT-IVUS imaging. All of those described methods may allow us to identify the most vulnerable plaques, which are prone to cause acute coronary syndrome, and thus they may allow us to introduce proper treatment before plaque destabilization.

Intensive lipid lowering agents and coronary atherosclerosis: Insights from intravascular imaging

Advances in intravascular imaging have permitted comprehensive evaluation of coronary atherosclerotic plaque from the perspective of its burden and individual components. These advances have been integrated in clinical trials that have evaluated the impact of intensive lipid lowering regimens. These trials have demonstrated that intensive lipid lowering, using high dose statins as monotherapy and in combination with new lipid lowering agents, produce favorable effects on coronary atheroma, resulting in regression and stabilization. These findings provide important biological insights to understand how intensive lipid lowering may reduce cardiovascular risk. This review aims to provide the reader with a contemporary overview of the findings of these studies and to propose the potential clinical implications for management of higher risk patients with atherosclerotic coronary artery disease.

Aortic stenosis in homozygous familial hypercholesterolaemia: a paradigm shift over a century

AIMS

Homozygous familial hypercholesterolaemia (HoFH) is an orphan disease defined by extreme elevations in low-density lipoprotein cholesterol, cutaneous xanthomas, and pre-mature atherosclerotic cardiovascular disease. Survival has more than doubled over the past three decades. Aortic stenosis (AS) [supravalvular aortic stenosis (SVAS) or valvular aortic stenosis (VAS)] is commonly encountered. There are no medical treatments available and complex high-risk surgeries represent the only available option in severe cases. A systematic review was performed to summarize the current evidence on AS in HoFH and to determine whether pharmacological treatment (statins) have had an impact on clinical presentation, phenotype and clinical course over the past nine decades (PROSPERO CRD42021250565).

METHODS AND RESULTS

MEDLINE, Embase Classic + Embase, Cochrane Central Register of Controlled Trials, PubMed, AfricaWide, and Scopus were searched from inception to 10 November 2021. Searches identified 381 publications, of which 19 were retained; they were cross-sectional or retrospective studies. Separately, 108 individual case reports were described. Within the 424 HoFH cases, AS was identified in 57% of patients in the pre-statin era vs. 35% in patients reported more recently (>2000, long-term statin period). With an increase in longevity due to statins and lipoprotein apheresis, a change in the proportion of patients with SVAS and VAS with a SVAS:VAS ratio of 47:53 and 10:90 for HoFH patients not on statin and on long-term statin, respectively, was noted.

CONCLUSION

These data suggest that SVAS and VAS are frequent in HoFH and that the phenotype has shifted towards calcific VAS as statins and lipoprotein apheresis improve survival in these patients.

Clinical determinants of coronary artery disease burden and vulnerability using optical coherence tomography co-registered with intravascular ultrasound

OBJECTIVES

We investigated clinical determinants of disease burden and vulnerability using optical coherence tomography (OCT) co-registered with intravascular ultrasound (IVUS) in a large cohort of patients.

METHODS

A total of 704 patients [44.5% with acute coronary syndromes (ACS)] underwent coronary intervention. IVUS plaque burden and OCT lipid, macrophage and calcium indices and the presence of thrombus, plaque rupture and thin-cap fibroatheroma (TCFA) were analyzed.

RESULTS

Median patient age was 66 years with 81.8% men, 34.4% with diabetes mellitus and 15.5% with preadmission statins. Median lesion length was 25.7 mm, and 33.0% had a TCFA. Adjusted models indicated (1) older patient age was related to more calcium, but fewer macrophages; (2) men were related to more thrombus with plaque rupture while women had more thrombus without plaque rupture; (3) ACS presentation was related to morphological acute thrombotic events (more thrombus with/without rupture) and plaque vulnerability (more TCFA, more lipid and macrophages and larger plaque burden); (4) diabetes mellitus was related to a greater atherosclerotic disease burden (more lipid and calcium and larger plaque burden) and more thrombus without rupture; (5) hypertension was related to more macrophages; (6) current smoking was related to less calcium; and (7) renal insufficiency and preadmission statin therapy were not independently associated with IVUS or OCT plaque morphology.

CONCLUSION

Patient characteristics, especially diabetes mellitus and aging, affect underlying atherosclerotic burden, among which a greater lipidic burden along with sex differences influence local thrombotic morphology that affects clinical presentation.

What Is Hidden Behind Yellow Pixels: from Pathology to Intravascular Imaging of Atherosclerotic Plaque

PURPOSE OF REVIEW

Intravascular imaging systems can identify lipid-rich and vulnerable plaques and help in treatment guidance. The comparability of different intracoronary imaging methods remains unclear. In this paper, we review atherosclerotic plaque pathology, plaque-stabilising effects of different lipid-lowering therapies and usage of intravascular imaging modalities. We present the results of our study in which we evaluated the correlation of the intravascular ultrasound iMAP system (iMAP-IVUS) and near-infrared spectroscopy (NIRS) in the diagnosis of vulnerable coronary plaques.

RECENT FINDINGS

Lipids have an essential contribution to plaque evolution and vulnerability. Increase in plaque vulnerability alone even without increase in plaque burden defines progression of atherosclerosis. Lipidic tissue has a significant diagnostic value in patient risk stratification and can serve as a treatment target. Different vulnerable plaque parameters can be visualised with iMAP-IVUS and NIRS. Intravascular imaging systems can differ with regard to their sensitivity, specificity and limitations. Lipid-lowering therapy is crucial in plaque stabilisation.

Pharmacogenetic loci for rosuvastatin are associated with intima-media thickness change and coronary artery disease risk

Aim: Polymorphisms at LPA, LDLR, APOE, APOC1, MYLIP and ABCG2 are attractive targets for assessment of their impact on lipid-lowering therapy with rosuvastatin. The present study investigated whether polymorphisms at these genes are associated with the risk of coronary artery disease (CAD) development, and reduction of atherogenic lipids and carotid intima-media thickness (CIMT) in CAD patients, taking rosuvastatin. Materials & methods: 190 CAD patients and 1697 subjects were enrolled in pharmacogenetic and genetic association study, respectively. SNP genotyping was done using the MassARRAY-4 system. Results:MYLIP rs6924995, rs3757354, APOC1 rs445925, LDLR rs6511720, APOE rs7412, ABCG2 rs2199936, rs1481012 variants were significantly associated with CAD susceptibility (p = 0.016, 0.0003, <0.0001, <0.0001, 0.013, 0.016, 0.0035, respectively), as well as with CIMT regression (except ABCG2 variants; p = 0.05, 0.039, 0.039, 0.016, 0.0065), and changes in plasma lipids during rosuvastatin therapy. Conclusion: The studied polymorphisms possess pleiotropic effects on plasma lipids and CIMT, CAD susceptibility, and determine lipid-lowering response to rosuvastatin.

The impact of lipid-lowering medications on coronary artery plaque characteristics

Atherosclerosis is the predominant cause of coronary artery disease. The last several decades have witnessed significant advances in lipid-lowering therapies, which comprise a central component of atherosclerotic cardiovascular disease prevention. In addition to cardiovascular risk reduction with dyslipidemia management, some lipid-based therapies show promise at the level of the atherosclerotic plaque itself through mechanisms governing lipid accumulation, plaque stability, local inflammation, endothelial dysfunction, and thrombogenicity. The capacity of lipid-lowering therapies to modify atherosclerotic plaque burden, size, composition, and vulnerability should correlate with their ability to reduce disease progression. This review discusses plaque characteristics, diagnostic modalities to evaluate these characteristics, and how they are altered by current and emerging lipid-lowering therapies, all in human coronary artery disease.

Inflammation during the life cycle of the atherosclerotic plaque

Inflammation orchestrates each stage of the life cycle of atherosclerotic plaques. Indeed, inflammatory mediators likely link many traditional and emerging risk factors with atherogenesis. Atheroma initiation involves endothelial activation with recruitment of leucocytes to the arterial intima, where they interact with lipoproteins or their derivatives that have accumulated in this layer. The prolonged and usually clinically silent progression of atherosclerosis involves periods of smouldering inflammation, punctuated by episodes of acute activation that may arise from inflammatory mediators released from sites of extravascular injury or infection or from subclinical disruptions of the plaque. Smooth muscle cells and infiltrating leucocytes can proliferate but also undergo various forms of cell death that typically lead to formation of a lipid-rich 'necrotic' core within the evolving intimal lesion. Extracellular matrix synthesized by smooth muscle cells can form a fibrous cap that overlies the lesion's core. Thus, during progression of atheroma, cells not only procreate but perish. Inflammatory mediators participate in both processes. The ultimate clinical complication of atherosclerotic plaques involves disruption that provokes thrombosis, either by fracture of the plaque's fibrous cap or superficial erosion. The consequent clots can cause acute ischaemic syndromes if they embarrass perfusion. Incorporation of the thrombi can promote plaque healing and progressive intimal thickening that can aggravate stenosis and further limit downstream blood flow. Inflammatory mediators regulate many aspects of both plaque disruption and healing process. Thus, inflammatory processes contribute to all phases of the life cycle of atherosclerotic plaques, and represent ripe targets for mitigating the disease.

The changing landscape of the vulnerable plaque: a call for fine-tuning of preclinical models

For decades, the pathological definition of the vulnerable plaque led to invaluable insights into the mechanisms that underlie myocardial infarction and stroke. Beyond plaque rupture, other mechanisms, such as erosion, may elicit thrombotic events underlining the complexity and diversity of the atherosclerotic disease. Novel insights, based on single-cell transcriptomics and other "omics" methods, provide tremendous opportunities in the ongoing search for cell-specific determinants that will fine-tune the description of the thrombosis prone lesion. It coincides with an increasing awareness that knowledge on lesion characteristics, cell plasticity and clinical presentation of ischemic cardiovascular events have shifted over the past decades. This shift correlates with an observed changes of cell composition towards phenotypical stabilizing of human plaques. These stabilization features and mechanisms are directly mediated by the cells present in plaques and can be mimicked in vitro via primary plaque cells derived from human atherosclerotic tissues. In addition, the rapidly evolving of sequencing technologies identify many candidate genes and molecular mechanisms that may influence the risk of developing an atherosclerotic thrombotic event - which bring the next challenge in sharp focus: how to translate these cell-specific insights into tangible functional and translational discoveries?

Reduction of Lipid-Core Burden Index in Nonculprit Lesions at Follow-Up after ST-Elevation Myocardial Infarction: A Randomized Study of Bioresorbable Vascular Scaffold versus Optimal Medical Therapy

BACKGROUND

Non-flow-limiting nonculprit lesions (NCL) that contain a large lipid-rich necrotic core (nonculprit lipid-rich plaques (NC-LRP)) are most likely to cause recurrent acute coronary syndrome after ST-elevation myocardial infarction (STEMI). Near-infrared spectroscopy (NIRS) detects LRPs using the maximum 4 mm lipid-core burden index (maxLCBI4 mm). Few data are available regarding NIRS-guided therapy of these NC-LRPs, which are a potential target for preventive stenting. Bioresorbable vascular scaffold (BVS) provides local drug delivery and could facilitate plaque passivation after resorption. This study sought to assess the safety of BVS implantation in NC-LRPs and its efficacy in reducing maxLCBI4 mm at 2-year follow-up after STEMI.

METHODS AND RESULTS

In total, 33 non-flow-limiting NCLs from 29 STEMI patients were included in this study. Of these, 15 were LRPs and were randomly assigned to either the BVS + optimal medical therapy (OMT) arm (group 1; N = 7) or the OMT arm (group 2; N = 8). At baseline, there were no differences in plaque characteristics between groups (fractional flow reserve: 0.85 ± 0.04 vs. 0.89 ± 0.06; diameter stenosis (DS): 43.4 ± 8 vs. 40.1 ± 10.7%; plaque burden 54.98 ± 5.8 vs. 49.76 ± 8.31%; and maxLCBI4 mm 402 [348; 564] vs. 373 [298; 516]; p=NS for all comparisons between groups 1 and 2, respectively). Seven BVSs were implanted 3 ± 1 days after STEMI in six patients, without complications. At angiographic follow-up (712 [657; 740] days), a significant and similar reduction of maxLCBI4 mm was observed in both groups, with a median change of 306 [257; 377] in group 1 vs. 300 [278; 346] in group 2 (p=0.44). DS was significantly lower in group 1 vs. group 2 (19.8 ± 7 vs. 41.7 ± 13%, p=0.003), while plaque burden remained unchanged in both groups. Overall survival was 100%, target lesion failure was 13%, and stent thrombosis was 0%.

CONCLUSIONS

BVS + OMT and OMT appear as similarly safe and effective in reducing maxLCBI4mm in NC-LRPs at 2-year follow-up after STEMI.

Low-density lipoproteins cause atherosclerotic cardiovascular disease: pathophysiological, genetic, and therapeutic insights: a consensus statement from the European Atherosclerosis Society Consensus Panel

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Anti-inflammatory Treatment and Cardiovascular Outcomes: Results of Clinical Trials

Atherosclerosis is a chronic inflammatory disorder of the vasculature where cholesterol accumulates in the arterial wall stimulating infiltration of immune cells. This plays an important role in plaque formation, as well as complications caused by its build up. Pro-inflammatory cytokines and chemokines are implicated throughout the progression of the disease and different therapies that aim to resolve this chronic inflammation, reduce cardiovascular (CV) events and improve clinical outcomes have been tested. The results from the pivotal CANTOS trial show that targeting the pro-inflammatory cytokine IL-1β successfully reduces the incidence of secondary CV events. This review briefly assesses the role of inflammation in atherosclerosis, providing a picture of the multiple players involved in the process and offering a perspective on targeting inflammation to prevent atherosclerotic CV events, as well as focusing on the results of the latest Phase III clinical trials.

Ultrasound Methods in the Evaluation of Atherosclerosis: From Pathophysiology to Clinic

Atherosclerosis is a key pathological process that causes a plethora of pathologies, including coronary artery disease, peripheral artery disease, and ischemic stroke. The silent progression of the atherosclerotic disease prompts for new surveillance tools that can visualize, characterize, and provide a risk evaluation of the atherosclerotic plaque. Conventional ultrasound methods-bright (B)-mode US plus Doppler mode-provide a rapid, cost-efficient way to visualize an established plaque and give a rapid risk stratification of the patient through the Gray-Weale standardization-echolucent plaques with ≥50% stenosis have a significantly greater risk of ipsilateral stroke. Although rather disputed, the measurement of carotid intima-media thickness (C-IMT) may prove useful in identifying subclinical atherosclerosis. In addition, contrast-enhanced ultrasonography (CEUS) allows for a better image resolution and the visualization and quantification of plaque neovascularization, which has been correlated with future cardiovascular events. Newly emerging elastography techniques such as strain elastography and shear-wave elastography add a new dimension to this evaluation-the biomechanics of the arterial wall, which is altered in atherosclerosis. The invasive counterpart, intravascular ultrasound (IVUS), enables an individualized assessment of the anti-atherosclerotic therapies, as well as a direct risk assessment of these lesions through virtual histology IVUS.

Multi-modality intravascular imaging for guiding coronary intervention and assessing coronary atheroma: the Novasight Hybrid IVUS-OCT system

Intravascular imaging has evolved alongside interventional cardiology as an adjunctive tool for assessing plaque pathology and for guiding and optimising percutaneous coronary intervention (PCI) in challenging lesions. The two modalities which have dominated the field are intravascular ultrasound (IVUS), which relies on sound waves and optical coherence tomography (OCT), relying on light waves. These approaches however have limited efficacy in assessing plaque morphology and vulnerability that are essential for guiding PCI in complex lesions and identifying patient at risk that will benefit from emerging therapies targeting plaque evolution. These limitations are complementary and, in this context, it has been recognised and demonstrated in multi-modality studies that the concurrent use of IVUS and OCT can help overcome these deficits enabling a more complete and accurate plaque assessment. The Conavi Novasight Hybrid IVUS-OCT catheter is the first commercially available device that is capable of invasive clinical coronary assessment with simultaneously acquired and co-registered IVUS and OCT imaging. It represents a significant evolution in the field and is expected to have broad application in clinical practice and research. In this review article we present the limitations of standalone intravascular imaging techniques, summarise the data supporting the value of multimodality imaging in clinical practice and research, describe the Novasight Hybrid IVUS-OCT system and highlight the potential utility of this technology in coronary intervention and in the study of atherosclerosis.

Added value of cardiovascular calcifications for prediction of recurrent cardiovascular events and cardiovascular interventions in patients with established cardiovascular disease

The purpose is to investigate the added prognostic value of coronary artery calcium (CAC), thoracic aortic calcium (TAC), and heart valve calcium scores for prediction of a combined endpoint of recurrent major cardiovascular events and cardiovascular interventions (MACE +) in patients with established cardiovascular disease (CVD). In total, 567 patients with established CVD enrolled in a substudy of the UCC-SMART cohort, entailing cardiovascular CT imaging and calcium scoring, were studied. Five Cox proportional hazards models for prediction of 4-year risk of MACE + were developed; traditional CVD risk predictors only (model I), with addition of CAC (model II), TAC (model III), heart valve calcium (model IV), and all calcium scores (model V). Bootstrapping was performed to account for optimism. During a median follow-up of 3.43 years (IQR 2.28–4.74) 77 events occurred (MACE+). Calibration of predicted versus observed 4-year risk for model I without calcium scores was good, and the c-statistic was 0.65 (95%CI 0.59–0.72). Calibration for models II–V was similar to model I, and c-statistics were 0.67, 0.65, 0.65, and 0.68 for model II, III, IV, and V, respectively. NRIs showed improvement in risk classification by model II (NRI 15.24% (95%CI 0.59–29.39)) and model V (NRI 20.00% (95%CI 5.59–34.92)), but no improvement for models III and IV. In patients with established CVD, addition of the CAC score improved performance of a risk prediction model with classical risk factors for the prediction of the combined endpoint MACE+ . Addition of the TAC or heart valve score did not improve risk predictions.

Atherosclerosis: Making a U Turn

The development of potent cholesterol-reducing medications in the last decade of the twentieth century has altered the approach to prevention and treatment of cardiovascular disease (CVD). Initial experience with statins, and more recently with the addition of PCSK9 inhibitors, has proven that human CVD, like that in animal models, can be halted and regressed. Available clinical data show that the lower the achieved level of low-density lipoprotein cholesterol, the greater the regression of disease. Investigative studies are now aimed to understand those factors that both accelerate and impede this healing process. Some of these are likely to be modifiable, and the future of atherosclerotic CVD treatment is likely to be early screening, use of measures to repair atherosclerotic arteries, and prevention of most CVD events.

Coronary plaque burden, plaque characterization and their prognostic implications in familial hypercholesterolemia: A computed tomographic angiography study

BACKGROUND AND AIMS

Heterozygous familial hypercholesterolemia (FH) is associated with premature atherosclerotic cardiovascular disease. Semi-automated plaque characterization (SAPC) by coronary computed tomographic angiography (CTA) provides information regarding coronary plaque burden and plaque characterization. Our aim was to quantify and characterize the coronary plaque burden of patients with FH using SAPC analysis and to identify which factors are related to plaque burden and plaque characteristics. A second aim was to analyse the prognostic implications of these parameters.

METHODS

Two hundred and fifty-nine asymptomatic individuals with molecularly determined FH were enrolled in this follow-up cohort study and underwent a coronary CTA analysed with SAPC.

RESULTS

Mean follow-up time after coronary CTA was 3.9 ± 2 years. Mean age was 46.9 (10.7) years (130 women, 50.2%). Median plaque burden was 25.0% (19.0-29.0), non-calcified plaque burden 22.83% (17.94-26.88), calcified plaque-burden 1.12% (0.31-2.86) and CCS 8.9 (0-93). Five-year risk was independently related to plaque burden, non-calcified plaque burden, calcified plaque burden and coronary calcium score (B:3.75, 95%CI:2.92-4.58; p < 0.001, B:2.9, 95%CI:2.15-3.66; p < 0.001, B:0.75, 95%CI 0.4-1.1; p < 0.001 and B:82.2, 95%CI:49.28-115.16; p < 0.001 respectively). During follow-up, there were 15 (5.81%) nonfatal events and 1 (0.4%) fatal event. Plaque burden was significantly related to event-free survival during follow-up (HR:1.11; 95%CI:1.05-1.18; p < 0.001).

CONCLUSIONS

Coronary atherosclerosis and its qualitative components may be quantified by means of SAPC in patients with FH. Plaque burden, calcified plaque burden and non-calcified plaque burden were independently related to the estimated cardiovascular risk. Plaque burden was also related to prognosis.

Intra-coronary Imaging for the Evaluation of Plaque Modifications Induced by Drug Therapies for Secondary Prevention

PURPOSE OF REVIEW

Patients diagnosed with coronary artery disease are at a high risk of subsequent cardiovascular events; therefore, secondary prevention in the form of therapeutic lifestyle changes, and drug therapies is vital. This article aims to review potential application of intra-coronary imaging for the evaluation of plaque modifications, induced by medications for secondary prevention for CAD.

RECENT FINDINGS

Intra-coronary imaging provides detailed information on the atherosclerotic plaque which is the primary pathological substrate for the recurrent ischemic cardiovascular events. These modalities can detect features associated with high risk and allow serial in vivo imaging of lesions. Therefore, intravascular imaging tools have been used in landmark studies and played a role in improving our understanding of the disease processes. Changes in size and plaque composition over time can be evaluated by these tools and may help understanding the impact of a treatment. Moreover, surrogate imaging end points can be used when testing new drugs for secondary prevention.

C-reactive protein levels and plaque regression with evolocumab: Insights from GLAGOV

Objective

On-treatment levels of high sensitivity C-reactive protein (hsCRP) in statin-treated patients predict plaque progression and the prospective risk of atherosclerotic cardiovascular events. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors produce additional LDL-C lowering, reduce plaque burden and improve cardiovascular outcomes in statin-treated patients. It is unknown whether residual systemic inflammation attenuates their favorable effects on plaque burden.

Methods

GLAGOV compared the effects of treatment for 78 weeks with evolocumab or placebo on progression of coronary atherosclerosis in statin-treated patients with coronary artery disease.

Clinical demographics, biochemistry and changes in both the burden (percentage atheroma volume (PAV), total atheroma volume (TAV), n ​= ​413) and composition (n ​= ​162) of coronary plaque were evaluated in evolocumab-treated patients according to baseline hsCRP strata (<1, 1–3, >3 ​mg/L).

Results

The study cohort comprised 413 evolocumab-treated patients (32% low [<1 ​mg/L], 41% intermediate [1–3 ​mg/L] and 27% high [>3 ​mg/L] baseline hsCRP levels). Patients in the highest hsCRP stratum were more likely to be female and had a higher prevalence of diabetes, hypertension, and the metabolic syndrome. LDL-C levels were similar across the groups, however participants with higher hsCRP levels had higher triglyceride and lower HDL-C levels at baseline. At follow-up, the change in PAV from baseline (−0.87% [low] vs. −0.84% [intermediate] vs. −1.22% [high], p ​= ​0.46) and the proportion of patients experiencing any degree of regression (65.9% vs. 63.5% vs. 63.1%, p ​= ​0.88) was similar across hsCRP strata and when evaluated by levels of achieved LDL-C. There were no serial differences in plaque composition by hsCRP strata.

Conclusion

The ability of evolocumab to induce regression in statin-treated patients is not attenuated by the presence of enhanced systemic inflammation. This underscores the potential benefits of intensive lipid lowering, even in the presence of heightened inflammatory states.

In vivo imaging of vulnerable plaque with intravascular modalities: its advantages and limitations

In vivo imaging of plaque instability has been considered to have a great potential to predict future coronary events and evaluate the stabilization effect of novel anti-atherosclerotic medical therapies. Currently, there are several intravascular imaging modalities which enable to visualize plaque components associated with its vulnerability. These include virtual histology intravascular ultrasound (VH-IVUS), integrated backscatter IVUS (IB-IVUS), optical coherence tomography (OCT), near-infrared spectroscopy and coronary angioscopy. Recent studies have shown that these tools are applicable for risk stratification of cardiovascular events as well as drug efficacy assessment. However, several limitation exists in each modality. The current review paper will outline advantages and limitation of VH-IVUS, IB-IVUS, OCT, NIRS and coronary angioscopy imaging.

Significant Difference in Acute Coronary Lesions in Patients on Therapeutic Statin Therapy Compared to Those Without

Background Statin therapy has been shown to alter coronary plaque via decreasing lipid-rich pools, substituting with fibrocalcific plaque. We propose that acute coronary lesions in patients on therapeutic statin therapy, compared with patients not on statin therapy with elevated low-density lipoprotein (LDL) levels, will have features typically not associated with lipid-rich disease, such as lengthy fibrocalcific lesions, stent failure (in-stent restenosis and stent thrombosis), and/or bypass graft degeneration. Methods Charts and coronary angiograms of 143 consecutive patients from May 2016 to December 2018 with Type 1 Myocardial Infarction Fourth Universal Definition were retrospectively reviewed. Patients were divided into two groups: group 1, those on statin therapy with an LDL < 100 mg/dL, and group 2, those not on statin therapy with an LDL ≥ 100 mg/dL at the time of an acute coronary syndrome. Acute lesion characteristics and angioplasty techniques/equipment were recorded. Results There were 56 patients in group 1 and 39 patients in group 2. Group 1 patients, compared with group 2, were more likely to have moderate-severe vessel calcification (55.4% vs 10.3%; p < 0.01), lesion length greater than 20 mm (51.8% vs 23.1%; p = 0.019), stent failure (39.3% vs 7.7%; p < 0.01), and bypass graft failure (23.2% vs 7.7%; p = 0.04). Coronary interventions in group 1, compared with group 2, more often required adjunctive angioplasty techniques, including the need for multiple coronary wires, guide extender, thrombectomy, and circulatory support (51.8% vs 7.7%; p < 0.01). There was no significant difference between the number of culprit vessels, including the specific coronary culprit vessel identified between both groups. Conclusion Acute coronary lesions in patients on therapeutic statin therapy, compared to those not on statin therapy with an elevated LDL, tend to be longer, more calcific with increased vessel tortuosity and angulation, as well as from a stent or bypass graft failure mechanism. Furthermore, there is a signal for heightened procedural complexity in the arm with statin therapy. These clinical findings are likely the result of the altered natural history of plaque pathophysiology seen with statin therapy.

Effect of cholesterol re-supplementation and atorvastatin on plaque composition in the thoracic aorta of New Zealand white rabbits

BACKGROUND

Effects of re-supplementation of a cholesterol-enriched diet (CEDrs) on size, cholesterol content and morphology of already existing plaques are not known to date.

METHODS

A group of rabbits received standard chow (SC) for 6 weeks ("negative control"; for plasma lipid measurements only). Group I-IV received 2% CED (induction) for 6 weeks; thereafter, groups II-IV have been fed a SC (= cholesterol withdrawal) for 68 weeks. Afterwards, feeding of groups II-IV was continued as follows: Group II - 10 weeks SC, group III - 4 weeks 0.5% CED (~re-supplementation), afterwards 6 weeks SC (~withdrawal again); group IV - 4 weeks 0.5% CED (re-supplementation) + atorvastatin (2.5 mg/kg body weight/day), afterwards 6 weeks SC (~withdrawal again) + atorvastatin. Plasma lipids, but also plaque size, morphology and cholesterol contents of thoracic aortas were quantified.

RESULTS

After CEDrs, plasma cholesterol levels were increased. However, after withdrawal of CEDrs, plasma cholesterol levels decreased, whereas the cholesterol content of the thoracic aorta was increased in comparison with the group without CEDrs. Plaque size remained unaffected. Atorvastatin application did not change plasma cholesterol level, cholesterol content of the thoracic aorta and plaque size in comparison with the group without drug treatment. However, atorvastatin treatment increased the density of macrophages (MΦ) compared with the group without treatment, with a significant correlation between densities of MΦ (Mac-1⁺) and apoptotic (TUNEL⁺; TP53⁺), antigen-presenting (HLA-DR⁺) or oxidatively stressed (SOD2⁺) cells.

CONCLUSIONS

In rabbits with already existing plaques, CEDrs affects plaque morphology and cellular composition, but not plaque size. Despite missing effects on plasma cholesterol levels, cholesterol content of the thoracic aorta and size of already existing atherosclerotic plaques, atorvastatin treatment transforms the already existing lesions to a more active form, which may accelerate the remodelling to a more stable plaque.

Coronary and peripheral artery plaques: do differences in plaque characteristics translate to differences in lipid management?

Optimal medical management of patients with peripheral arterial disease (PAD) includes statin therapy, which has been shown to decrease the risk of major cardiovascular events. However, the relationship between low-density lipoprotein (LDL) lowering, PAD progression and limb outcomes remains controversial. Although prevention of coronary and cerebrovascular events is a priority, limb outcomes are still important determinants of quality of life and healthcare spending. This review will highlight differences between coronary artery disease (CAD) and PAD, and in particular, the more prevalent role of lipids and LDL cholesterol in CAD versus calcification in PAD. This difference may contribute to the differential impact of LDL cholesterol levels on coronary events and outcomes versus limb outcomes. Beyond LDL lowering, immune modulators have emerged as another agent to treat atherosclerosis in CAD, however similar data in PAD are lacking. Small studies have suggested that other lipids besides LDL cholesterol, such as triglycerides or small dense LDL, may have a greater impact on limb outcomes in patients with PAD. Although statin therapy is central in the management of patients with PAD, current understanding of the distinctions between PAD and CAD suggest that there may be other non-LDL targets for risk reduction that require further study.

Proportion of High-Risk/Very High-Risk Patients in Europe with Low-Density Lipoprotein Cholesterol at Target According to European Guidelines: A Systematic Review

OBJECTIVE

Assess achievement of low-density lipoprotein cholesterol (LDL-C) targets in European Society of Cardiology (ESC)/European Atherosclerosis Society (EAS) guidelines.

DESIGN

Systematic literature review.

DATA SOURCES

Medline, EMBASE, Cumulated Index to Nursing and Allied Health Literature.

ELIGIBILITY CRITERIA

Observational studies reporting LDL-C levels/target attainment, measured between 1 August 2006 to 31 August 2017, in European adults with established cardiovascular disease (CVD), diabetes with target organ damage, familial hypercholesterolaemia (FH) or 10-year risk of fatal CVD ≥ 5% (assessed by Systematic Coronary Risk Evaluation [SCORE]).

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted relevant studies and assessed study quality using the Risk of Bias for Non-Randomised Studies-Interventions (ROBINS-I) tool. Primary outcome was the proportion of patients achieving LDL-C targets in the 2011/2016 ESC/EAS guidelines. Where available, patient characteristics were presented as means weighted by sample size. The proportions of patients achieving LDL-C targets in the 5 years before and after publication of the 2011 guidelines were compared using a chi-square test.

RESULTS

Across 81 eligible studies (303,534 patients), achievement of LDL-C < 1.8 mmol/L was poor among patients with established CVD (16%; range 9-56%) and at very high risk of CVD (SCORE ≥ 10% [18%; 14-25%]). In individuals with FH, SCORE 5-10%, or diabetes and target organ damage, LDL-C < 2.5 mmol/L was achieved by 15% (9-22%), 46% (21-55%) and 13% (6-34%), respectively. Comparing the 5 years before/after publication of the 2011 guidelines, target achievement increased significantly over time but remained suboptimal (LDL-C < 1.8, 22% versus 15%; LDL-C < 2.5, 68% versus 61%; both p < 0.001; established CVD group only).

CONCLUSIONS

These data show suboptimal LDL-C control among European patients at high risk of CVD. Those at greatest overall risk (clinically established CVD or at least a 10% 10-year risk of fatal CVD) had the lowest achievement of 2011/2016 EAS/ESC LDL-C targets. With lower LDL-C targets advocated in 2019 ESC/EAS guidelines, this unmet need will increase.

PROTOCOL REGISTRATION

PROSPERO registration number; CRD77844.

Progression of ultrasound plaque attenuation and low echogenicity associates with major adverse cardiovascular events

Aims

Intravascular ultrasound (IVUS) imaging can visualize vulnerable plaque features including attenuation (AP) and echolucency (ELP). While IVUS-derived vulnerable plaque features associate with microvascular obstruction during percutaneous coronary intervention, the relationship between these plaque features and clinical outcomes has not been established. This analysis aimed to evaluate the association of AP/ELP with cardiovascular events.

Methods and results

Serial IVUS imaging was reviewed in 1497 patients, followed for 18–24 months, with coronary artery disease from two clinical trials. Attenuated plaque and ELP were identified to measure each characteristics (AP arc, ELP area, and lengths), which permitted calculation of an AP index (API) and ELP volume. Attenuated plaque/ELP progression was defined as patients with any increase of API or ELP volume on serial imaging. The major cardiovascular events (MACEs) were defined as death, myocardial infarction, stroke, and coronary revascularization. AP or ELP was identified in 282 patients (18.8%) at baseline and 160 (10.7%) patients demonstrated an increase in AP or ELP at follow-up. The incidence of MACE was higher in patients with baseline AP/ELP than those without (8.2% vs. 3.9%, P = 0.002). Patients with AP/ELP progression were more likely to be acute coronary syndrome (41.9 vs. 33.2%, P = 0.03) and have greater baseline percent atheroma volume (40.0% vs. 35.8%, P &lt; 0.001) than those without. On multivariable analysis, AP/ELP progression was more strongly associated with MACE [baseline AP/ELP: hazard ratio (HR) 1.76, 95% confidence interval (CI) 1.05–2.97, AP/ELP progression: HR 2.19, 95% CI 1.24–3.86].

Conclusion

Attenuation/ELP progression was associated with a higher prevalence of cardiovascular events, supporting a potential role for the identification of high-risk vulnerable plaques in patients with coronary artery disease.

Ca2+ Flux: Searching for a Role in Efferocytosis of Apoptotic Cells in Atherosclerosis

In atherosclerosis, macrophages in the arterial wall ingest plasma lipoprotein-derived lipids and become lipid-filled foam cells with a limited lifespan. Thus, efficient removal of apoptotic foam cells by efferocytic macrophages is vital to preventing the dying foam cells from forming a large necrotic lipid core, which, otherwise, would render the atherosclerotic plaque vulnerable to rupture and would cause clinical complications. Ca2+ plays a role in macrophage migration, survival, and foam cell generation. Importantly, in efferocytic macrophages, Ca2+ induces actin polymerization, thereby promoting the formation of a phagocytic cup necessary for efferocytosis. Moreover, in the efferocytic macrophages, Ca2+ enhances the secretion of anti-inflammatory cytokines. Various Ca2+ antagonists have been seminal for the demonstration of the role of Ca2+ in the multiple steps of efferocytosis by macrophages. Moreover, in vitro and in vivo experiments and clinical investigations have revealed the capability of Ca2+ antagonists in attenuating the development of atherosclerotic plaques by interfering with the deposition of lipids in macrophages and by reducing plaque calcification. However, the regulation of cellular Ca2+ fluxes in the processes of efferocytic clearance of apoptotic foam cells and in the extracellular calcification in atherosclerosis remains unknown. Here, we attempted to unravel the molecular links between Ca2+ and efferocytosis in atherosclerosis and to evaluate cellular Ca2+ fluxes as potential treatment targets in atherosclerotic cardiovascular diseases.

The Role of Vascular Smooth Muscle Cells in Arterial Remodeling: Focus on Calcification-Related Processes

Arterial remodeling refers to the structural and functional changes of the vessel wall that occur in response to disease, injury, or aging. Vascular smooth muscle cells (VSMC) play a pivotal role in regulating the remodeling processes of the vessel wall. Phenotypic switching of VSMC involves oxidative stress-induced extracellular vesicle release, driving calcification processes. The VSMC phenotype is relevant to plaque initiation, development and stability, whereas, in the media, the VSMC phenotype is important in maintaining tissue elasticity, wall stress homeostasis and vessel stiffness. Clinically, assessment of arterial remodeling is a challenge; particularly distinguishing intimal and medial involvement, and their contributions to vessel wall remodeling. The limitations pertain to imaging resolution and sensitivity, so methodological development is focused on improving those. Moreover, the integration of data across the microscopic (i.e., cell-tissue) and macroscopic (i.e., vessel-system) scale for correct interpretation is innately challenging, because of the multiple biophysical and biochemical factors involved. In the present review, we describe the arterial remodeling processes that govern arterial stiffening, atherosclerosis and calcification, with a particular focus on VSMC phenotypic switching. Additionally, we review clinically applicable methodologies to assess arterial remodeling and the latest developments in these, seeking to unravel the ubiquitous corroborator of vascular pathology that calcification appears to be.