Effects of Fatty Acid Therapy in Addition to Strong Statin on Coronary Plaques in Acute Coronary Syndrome: An Optical Coherence Tomography Study

Lipid-lowering Therapy and Coronary Plaque Regression

Lipid-lowering therapy plays a central role in reducing cardiovascular events. Over the past few decades, clinical trials utilizing several imaging techniques have consistently shown that lipid-lowering therapy can reduce the coronary plaque burden and improve plaque composition. Although intravascular ultrasound has been the most extensively used modality to assess plaque burden, other invasive modalities, such as optical coherence tomography and near-infrared spectroscopy, provide relevant data on plaque vulnerability, and computed tomography angiography detects both plaque volume and characteristics non-invasively. A large body of evidence supports the notion that reducing low-density lipoprotein cholesterol using statins combined with ezetimibe and proprotein convertase subtillisin/kexin type 9 inhibitors consistently shows improvements in plaque burden and favorable morphological changes. This review summarizes previously obtained data on the impact of lipid-lowering treatment strategies on atherosclerotic plaque regression, as assessed using several imaging modalities.

Advancements in risk stratification and management strategies in primary cardiovascular prevention

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of morbidity and mortality worldwide, highlighting the urgent need for advancements in risk assessment and management strategies. Although significant progress has been made recently, identifying and managing apparently healthy individuals at a higher risk of developing atherosclerosis and those with subclinical atherosclerosis still poses significant challenges. Traditional risk assessment tools have limitations in accurately predicting future events and fail to encompass the complexity of the atherosclerosis trajectory. In this review, we describe novel approaches in biomarkers, genetics, advanced imaging techniques, and artificial intelligence that have emerged to address this gap. Moreover, polygenic risk scores and imaging modalities such as coronary artery calcium scoring, and coronary computed tomography angiography offer promising avenues for enhancing primary cardiovascular risk stratification and personalised intervention strategies. On the other hand, interventions aiming against atherosclerosis development or promoting plaque regression have gained attention in primary ASCVD prevention. Therefore, the potential role of drugs like statins, ezetimibe, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, omega-3 fatty acids, antihypertensive agents, as well as glucose-lowering and anti-inflammatory drugs are also discussed. Since findings regarding the efficacy of these interventions vary, further research is still required to elucidate their mechanisms of action, optimize treatment regimens, and determine their long-term effects on ASCVD outcomes. In conclusion, advancements in strategies addressing atherosclerosis prevention and plaque regression present promising avenues for enhancing primary ASCVD prevention through personalised approaches tailored to individual risk profiles. Nevertheless, ongoing research efforts are imperative to refine these strategies further and maximise their effectiveness in safeguarding cardiovascular health.

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.

Effects of omega-3, omega-6, and total dietary polyunsaturated fatty acid supplementation in patients with atherosclerotic cardiovascular disease: a systematic review and meta-analysis

Background: Uncertainty exists about the link between omega-3 fatty acid, omega-6 fatty acid, and total polyunsaturated fatty acid (PUFA) intake and mortality in atherosclerotic cardiovascular disease (ASCVD) patients, and no meta-analyses summarize the relationship between these various types of PUFAs and ASCVD. Methods: Web of Science, PubMed, EBSCO and Cochrane Library up to November 30, 2022 were searched for prospective randomized controlled studies investigating the relationships among omega-3, omega-6, and PUFA intake and mortality and cardiovascular events in ASCVD patients. This study has been registered at PROSPERO (No. CRD42023407566). Results: This meta-analysis included 21 publications from 17 studies involving 40 861 participants published between 1965 and 2022. In ASCVD patients, omega-3 may lower all-cause mortality (RR: 0.90, 95% CI [0.83, 0.98], I2 = 8%), CVD mortality (RR: 0.82, 95% CI [0.73, 0.91], I2 = 34%) and CVD events (RR: 0.90, 95% CI [0.86, 0.93], I2 = 79%). Subgroup analyses showed that EPA or EPA ethyl ester supplementation reduced CVD events, while the mixture of EPA and DHA had no significant impact. Long-chain omega-3 consumption of 1.0-4.0 g per d reduced death risk by 3.5% for each 1 g per d increase. Omega-6 and PUFA had no significant effect on mortality or CVD events, with low-quality evidence and significant heterogeneity. Conclusions: omega-3 intake is associated with a reduced risk of all-cause mortality, CVD mortality, and CVD events in ASCVD patients, while omega-6 or total PUFA intake showed no significant association. Increasing the omega-3 intake by 1 g per d resulted in a 3.5% decrease in the risk of death. These findings support the recommendation of supplements with omega-3 fatty acids for the secondary prevention of ASCVD.

Effect of Eicosapentaenoic Acid/Docosahexaenoic Acid on Coronary High-Intensity Plaques Detected Using Noncontrast T1-weighted Imaging: The AQUAMARINE EPA/DHA Randomized Study

AIM

Omega-3 fatty acids have emerged as a new option for controlling the residual risk for coronary artery disease (CAD) in the statin era. Eicosapentaenoic acid (EPA) is associated with reduced CAD risk in the Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention trial, whereas the Statin Residual Risk with Epanova in High Cardiovascular Risk Patients with Hypertriglyceridemia trial that used the combination EPA/docosahexaenoic acid (DHA) has failed to derive any clinical benefit. These contradictory results raise important questions about whether investigating the antiatherosclerotic effect of omega-3 fatty acids could help to understand their significance for CAD-risk reduction.

METHODS

The Attempts at Plaque Vulnerability Quantification with Magnetic Resonance Imaging Using Noncontrast T1-weighted Technic EPA/DHA study is a single-center, triple-arm, randomized, controlled, open-label trial used to investigate the effect of EPA/DHA on high-risk coronary plaques after 12 months of treatment, detected using cardiac magnetic resonance (CMR) in patients with CAD receiving statin therapy. Eligible patients were randomly assigned to no-treatment, 2-g/day, and 4-g/day EPA/DHA groups. The primary endpoint was the change in the plaque-to-myocardium signal intensity ratio (PMR) of coronary high-intensity plaques detected by CMR. Coronary plaque assessment using computed tomography angiography (CTA) was also investigated.

RESULTS

Overall, 84 patients (mean age: 68.2 years, male: 85%) who achieved low-density lipoprotein cholesterol levels of ＜100 mg/dL were enrolled. The PMR was reduced in each group over 12 months. There were no significant differences in PMR changes among the three groups in the primary analysis or analysis including total lesions. The changes in CTA parameters, including indexes for detecting high-risk features, also did not differ.

CONCLUSION

The EPA/DHA therapy of 2 or 4 g/day did not significantly improve the high-risk features of coronary atherosclerotic plaques evaluated using CMR under statin therapy.

Assessing the Efficacy of Omega-3 Fatty Acids + Statins vs. Statins Only on Cardiovascular Outcomes: A Systematic Review and Meta-Analysis of 40,991 Patients

BACKGROUND

Clinical guidelines recommend statin use in patients with a vast array of cardiovascular disturbances. However, there is insufficient evidence regarding the concomitant use of omega-3 fatty acids in addition to statins. This meta-analysis aims to uncover the complete effects of this combination therapy on cardiovascular outcomes, lipid biomarkers, inflammatory markers, and plaque markers.

METHODS

A detailed literature search was conducted using PubMed, Cochrane, and MEDLINE databases, and all the relevant studies found up to September 2023 were included. The primary outcomes assessed in this meta-analysis was 1) Composite of fatal and non-fatal myocardial infarction, 2) Composite of fatal and non-fatal stroke, 3) Coronary revascularization, 4) Death due to cardiovascular causes, 5) MACE (Major Adverse Cardiovascular Events), 6) Unstable angina, 7) Hospitalization due to unstable angina, 8) and lipid volume index. Secondary outcomes included lipid markers, hsCRP, EPA levels, and EPA/AA ratio.

RESULTS

14 RCTs were included, featuring a total of 40,991 patients. Patients receiving the omega-3 + statin regimen were associated with a statistically significant decrease in the incidence of MI, MACE, unstable angina, hospitalization due to unstable angina, Total cholesterol levels, triglycerides, hsCRP, and lipid volume index in comparison to their counterparts receiving placebo + statin (P < 0.05). In contrast, our analysis found no statistically significant difference in the incidence of fatal and non-fatal stroke, coronary revascularization, and cardiovascular mortality.

CONCLUSION

Our research reinforces that all patients, regardless of their cardiovascular health, may benefit from adding omega-3 fatty acids to their statin therapy.

Effectiveness of lipid-lowering therapy on mortality and major adverse cardiovascular event outcomes in patients undergoing percutaneous coronary intervention: a network meta-analysis of randomised controlled trials

BACKGROUND

Emergency percutaneous coronary intervention (PCI) can quickly restore myocardial perfusion after acute coronary syndrome. Whether and which lipid-lowering regimens are effective in reducing major adverse cardiovascular events (MACEs) and mortality risk after PCI remain unclear.

OBJECTIVE

This study assessed the benefits of different lipid-lowering regimens on the risk of MACEs and mortality in the post-PCI population by network meta-analysis.

METHODS

Public databases, including PubMed, Embase and the Cochrane Library, were searched from inception to August 2022. Randomised controlled trials (RCTs) on lipid-lowering regimens in post-PCI populations were included and analysed. The outcomes were the incidence of all-cause mortality and MACEs, whether reported as dichotomous variables or as HRs.

RESULTS

Thirty-nine RCTs were included. For MACEs, alirocumab plus rosuvastatin (OR: 0.18; 95% CI: 0.07 to 0.44), evolocumab plus ezetimibe and statins (OR: 0.19; 95% CI: 0.06 to 0.59), eicosapentaenoic acid (EPA) plus pitavastatin (HR: 0.67; 95% CI: 0.49 to 0.96) and icosapent ethyl plus statins (HR: 0.73; 95% CI: 0.62 to 0.86) had significant advantages and relatively high rankings. For mortality, rosuvastatin (OR: 0.30; 95% CI: 0.11 to 0.84), ezetimibe plus statins (OR: 0.55; 95% CI: 0.43 to 0.89) and icosapent ethyl plus statins (OR: 0.66; 95% CI: 0.45 to 0.96) had significant advantages compared with the control.

CONCLUSION

EPA, especially icosapent ethyl, plus statins had a beneficial effect on reducing the risk of MACEs and mortality in post-PCI patients. Proprotein convertase subtilisin/kexin type-9 inhibitors plus statins were able to reduce the risk of MACEs, but the risk of mortality remained unclear.

PROSPERO REGISTRATION NUMBER

CRD42018099600.

Association between Eicosapentaenoic Acid to Arachidonic Acid Ratio and Characteristics of Plaque Rupture

AIMS

Eicosapentaenoic acid (EPA) has shown beneficial effects on coronary plaque stabilization. Based on our previous study, we speculated that EPA might be associated with the development of healed plaques and might limit thrombus size. This study aimed to elucidate the association between EPA and arachidonic acid (AA) ratios and various plaque characteristics in patients with plaque rupture.

METHODS

A total of 95 patients with acute coronary syndrome (ACS) caused by plaque rupture who did not take lipid-lowering drugs and underwent percutaneous coronary intervention using optical coherence tomography (OCT) were included. Clinical characteristics, lipid profiles, and OCT findings were compared between patients with lower and higher EPA/AA ratios (0.41) according to the levels in the Japanese general population.

RESULTS

In the high EPA/AA (n=29, 30.5%) and low EPA/AA (n=66, 69.5 %) groups, the high EPA/AA group was significantly older (76.1 vs. 66.1 years, P＜0.01) and had lower peak creatine kinase (556 vs. 1651 U/L, P=0.03) than those with low EPA/AA. Similarly, patients with high EPA/AA had higher prevalence of layered and calcified plaque (75.9 vs. 39.4 %, P＜0.01; 79.3 vs. 50.0 %, P＜0.01, respectively) than low EPA/AA group. Multivariate logistic regression analysis demonstrated that a high EPA/AA ratio was an independent factor in determining the development of layered and calcified plaques.

CONCLUSION

A high EPA/AA ratio may be associated with the development of layered and calcified plaques in patients with plaque rupture.

Effect of Intensive Lipid-Lowering Therapy on Coronary Plaque Stabilization Derived from Optical Coherence Tomography: a Meta-analysis and Meta-regression

PURPOSE

The definitive impacts of intensive lipid-lowering therapy (LLT) on plaque stabilization and the relationship between the key markers during LLT and plaque stability remain unquestioned. Thus, these meta-analysis and meta-regression intend to holistically evaluate the influence exerted by rigorous LLT on the minimum fibrous cap thickness (FCT) and maximum lipid arc as discerned through optical coherence tomography (OCT). This study further scrutinizes the correlation of this impact with variations in high-sensitivity C-reactive protein (hs-CRP), low-density lipoprotein cholesterol (LDL-C), or additional parameters within patients diagnosed with coronary artery disease (CAD).

METHODS

Comprehensive searches were conducted on platforms including PubMed, Embase, and the Cochrane Library for randomized controlled trials (RCTs) published until June 1, 2023. The search was language agnostic and targeted RCTs elaborating on the correlation between high-intensity statin therapy or statins used concomitantly with other lipid-lowering medications and the minimum FCT and maximum lipid arc as assessed by OCT. The meta-analyses were executed employing a standard mean difference (SMD) algorithm with random-effects on continuous variables. These methodologies align with the Preferred Reporting Items for Systematic and Meta-analysis (PRISMA) guidelines.

RESULTS

A spectrum of 12 RCTs engaging 972 patients were identified and mobilized for these analyses. Meta-analysis outcomes depicted a conspicuous correlation between intensive LLT and an enhanced minimum FCT (12 studies with 972 participants; SMD, 0.87; 95% CI, 0.54 to 1.21; P < 0.01), reduced maximum lipid arc (9 studies with 564 participants; SMD, -0.43; 95% CI, -0.58 to -0.29; P < 0.01). Meta-regression analysis has determined an association of elevated minimum FCT with decreased LDL-C (β, -0.0157; 95% CI, -0.0292 to -0.0023; P = 0.025), total cholesterol (TC) (β, -0.0154; 95% CI, -0.0303 to -0.0005; P = 0.044), and apolipoprotein B (ApoB) (β, -0.0209; 95% CI, -0.0361 to -0.0057; P = 0.022). However, no significant association was discerned relative to variations in hs-CRP/CRP (β, -0.1518; 95% CI, -1.3766 to -1.0730; P = 0.772), triglyceride (TG) (β, -0.0030; 95% CI, -0.0258 to -0.0318; P = 0.822), and high-density lipoprotein cholesterol (HDL-C) (β, 0.0313; 95% CI, -0.0965 to 0.1590; P = 0.608). Subsequent subgroup meta-analysis demonstrated that high-intensity statin therapy (5 studies with 204 participants; SMD, 1.03; 95% CI, 0.67 to 1.39; P < 0.01), as well as a combinative approach including PCSK9 antibodies and statins (3 studies with 522 participants; SMD, 1.17; 95% CI, 0.62 to 1.73; P < 0.01) contributed to an increase in minimum FCT. Parallelly, high-intensity statin therapy (4 studies with 183 participants; SMD, -0.42; 95% CI, -0.65 to -0.19; P < 0.01) or the combined application of PCSK9 antibodies and statins (2 studies with 222 participants; SMD, -0.98; 95% CI, -1.26 to -0.70; P < 0.01) was evidenced to decrease the maximum lipid arc.

CONCLUSIONS

Intensive LLT, mainly high-intensity statin therapy and combined PCSK9 antibody with statin, has a beneficial effect on coronary plaque stabilization derived from OCT in patients with CAD. Coronary plaque stabilization is primarily due to lipid-lowering effect, not anti-inflammatory effect. Moreover, the lipid-lowering effect has nothing to do with the changes in HDL-C and TG, but is mainly related to the reduction of LDL-C, TC, and ApoB.

Higher docosahexaenoic acid levels lower the protective impact of eicosapentaenoic acid on long-term major cardiovascular events

Introduction

Long-chain omega-3 polyunsaturated fatty acids (OM3 PUFA) are commonly used for cardiovascular disease prevention. High-dose eicosapentaenoic acid (EPA) is reported to reduce major adverse cardiovascular events (MACE); however, a combined EPA and docosahexaenoic acid (DHA) supplementation has not been proven to do so. This study aimed to evaluate the potential interaction between EPA and DHA levels on long-term MACE.

Methods

We studied a cohort of 987 randomly selected subjects enrolled in the INSPIRE biobank registry who underwent coronary angiography. We used rapid throughput liquid chromatography-mass spectrometry to quantify the EPA and DHA plasma levels and examined their impact unadjusted, adjusted for one another, and fully adjusted for comorbidities, EPA + DHA, and the EPA/DHA ratio on long-term (10-year) MACE (all-cause death, myocardial infarction, stroke, heart failure hospitalization).

Results

The average subject age was 61.5 ± 12.2 years, 57% were male, 41% were obese, 42% had severe coronary artery disease (CAD), and 311 (31.5%) had a MACE. The 10-year MACE unadjusted hazard ratio (HR) for the highest (fourth) vs. lowest (first) quartile (Q) of EPA was HR = 0.48 (95% CI: 0.35, 0.67). The adjustment for DHA changed the HR to 0.30 (CI: 0.19, 0.49), and an additional adjustment for baseline differences changed the HR to 0.36 (CI: 0.22, 0.58). Conversely, unadjusted DHA did not significantly predict MACE, but adjustment for EPA resulted in a 1.81-fold higher risk of MACE (CI: 1.14, 2.90) for Q4 vs. Q1. However, after the adjustment for baseline differences, the risk of MACE was not significant for DHA (HR = 1.37; CI: 0.85, 2.20). An EPA/DHA ratio ≥1 resulted in a lower rate of 10-year MACE outcomes (27% vs. 37%, adjusted p-value = 0.013).

Conclusions

Higher levels of EPA, but not DHA, are associated with a lower risk of MACE. When combined with EPA, higher DHA blunts the benefit of EPA and is associated with a higher risk of MACE in the presence of low EPA. These findings can help explain the discrepant results of EPA-only and EPA/DHA mixed clinical supplementation trials.

Association Between Omega-3 Fatty Acid Intake and Dyslipidemia: A Continuous Dose-Response Meta-Analysis of Randomized Controlled Trials

Background Previous results provide supportive but not conclusive evidence for the use of omega-3 fatty acids to reduce blood lipids and prevent events of atherosclerotic cardiovascular disease, but the strength and shape of dose-response relationships remain elusive. Methods and Results This study included 90 randomized controlled trials, reported an overall sample size of 72 598 participants, and examined the association between omega-3 fatty acid (docosahexaenoic acid, eicosapentaenoic acid, or both) intake and blood lipid changes. Random-effects 1-stage cubic spline regression models were used to study the mean dose-response association between daily omega-3 fatty acid intake and changes in blood lipids. Nonlinear associations were found in general and in most subgroups, depicted as J-shaped dose-response curves for low-/high-density lipoprotein cholesterol. However, we found evidence of an approximately linear dose-response relationship for triglyceride and non-high-density lipoprotein cholesterol among the general population and more evidently in populations with hyperlipidemia and overweight/obesity who were given medium to high doses (>2 g/d). Conclusions This dose-response meta-analysis demonstrates that combined intake of omega-3 fatty acids near linearly lowers triglyceride and non-high-density lipoprotein cholesterol. Triglyceride-lowering effects might provide supportive evidence for omega-3 fatty acid intake to prevent cardiovascular events.

The Emerging Role of Icosapent Ethyl in Patients with Cardiovascular Disease: Mechanistic Insights and Future Applications

Omega-3 polyunsaturated fatty acids (PUFAs) were early established as therapeutic option for patients with high triglyceride levels. Their effects on lipoprotein particles, including a reduction in very low-density lipoprotein and a shift from small to large low-density lipoprotein, is increasingly recognised. This is coupled with their ability to be incorporated within the cellular membrane, leading to plaque stability and anti-inflammatory effects. Nonetheless, recent clinical trials have not been consistent in demonstrating the potential cardioprotective effects of omega-3 fatty acids. This is despite the circumstantial evidence from imaging studies illustrating the stabilising effects on atherosclerotic plaques and slowing of plaque progression. In this article, we will review the effects of omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on lipid biomarkers, atherosclerotic plaque features, and clinical outcome studies and provide a mechanistic role in managing residual risk of atherosclerosis. This will provide better insight into the inconsistency of the recently reported clinical outcome studies.

Cholesterol crystals and atherosclerotic plaque instability: Therapeutic potential of Eicosapentaenoic acid

Atherosclerotic plaques associated with acute coronary syndromes (ACS), i.e. culprit lesions, frequently feature a ruptured fibrous cap with thrombotic complications. On imaging, these plaques exhibit a low attenuation, lipid-rich, necrotic core containing cholesterol crystals and are inherently unstable. Indeed, cholesterol crystals are causally associated with plaque vulnerability in vivo; their formation results from spontaneous self-assembly of cholesterol molecules. Cholesterol homeostasis is a central determinant of the physicochemical conditions leading to crystal formation, which are favored by elevated membrane free cholesterol content in plaque endothelial cells, smooth muscle cells, monocyte-derived macrophages, and foam cells, and equally by lipid oxidation. Emerging evidence from imaging trials in patients with coronary heart disease has highlighted the impact of intervention involving the omega-3 fatty acid, eicosapentaenoic acid (EPA), on vulnerable, low attenuation atherosclerotic plaques. Thus, EPA decreased features associated with unstable plaque by increasing fibrous cap thickness in statin-treated patients, by reducing lipid volume and equally attenuating intraplaque inflammation. Importantly, atherosclerotic plaques rapidly incorporate EPA; indeed, a high content of EPA in plaque tissue is associated with decreased plaque inflammation and increased stability. These findings are entirely consistent with the major reduction seen in cardiovascular events in the REDUCE-IT trial, in which high dose EPA was administered as its esterified precursor, icosapent ethyl (IPE); moreover, clinical benefit was proportional to circulating EPA levels. Eicosapentaenoic acid is efficiently incorporated into phospholipids, where it modulates cholesterol-enriched domains in cell membranes through physicochemical lipid interactions and changes in rates of lipid oxidation. Indeed, biophysical analyses indicate that EPA exists in an extended conformation in membranes, thereby enhancing normal cholesterol distribution while reducing propagation of free radicals. Such effects mitigate cholesterol aggregation and crystal formation. In addition to its favorable effect on cholesterol domain structure, EPA/IPE exerts pleiotropic actions, including antithrombotic, antiplatelet, anti-inflammatory, and proresolving effects, whose plaque-stabilizing potential cannot be excluded. Docosahexaenoic acid is distinguished from EPA by a higher degree of unsaturation and longer carbon chain length; DHA is thus predisposed to changes in its conformation with ensuing increase in membrane lipid fluidity and promotion of cholesterol aggregation into discrete domains. Such distinct molecular effects between EPA and DHA are pronounced under conditions of high cellular cholesterol content and oxidative stress. This review will focus on the formation and role of cholesterol monohydrate crystals in destabilizing atherosclerotic plaques, and on the potential of EPA as a therapeutic agent to attenuate the formation of deleterious cholesterol membrane domains and of cholesterol crystals. Such a therapeutic approach may translate to enhanced plaque stability and ultimately to reduction in cardiovascular risk.

A biological rationale for the disparate effects of omega-3 fatty acids on cardiovascular disease outcomes

The omega-3 fatty acids (n3-FAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) rapidly incorporate into cell membranes where they modulate signal transduction pathways, lipid raft formation, and cholesterol distribution. Membrane n3-FAs also form specialized pro-resolving mediators and other intracellular oxylipins that modulate inflammatory pathways, including T-cell differentiation and gene expression. Cardiovascular (CV) trials have shown that EPA, administered as icosapent ethyl (IPE), reduces composite CV events, along with plaque volume, in statin-treated, high-risk patients. Mixed EPA/DHA regimens have not shown these benefits, perhaps as the result of differences in formulation, dosage, or potential counter-regulatory actions of DHA. Indeed, EPA and DHA have distinct, tissue-specific effects on membrane structural organization and cell function. This review summarizes: (1) results of clinical outcome and imaging trials using n3-FA formulations; (2) membrane interactions of n3-FAs; (3) effects of n3-FAs on membrane oxidative stress and cholesterol crystalline domain formation during hyperglycemia; (4) n3-FA effects on endothelial function; (5) role of n3-FA-generated metabolites in inflammation; and (6) ongoing and future clinical investigations exploring treatment targets for n3-FAs, including COVID-19.

Multimodality Imaging Trials Evaluating the Impact of Omega-3 Fatty Acids on Coronary Artery Plaque Characteristics and Burden

Treatment of established risk factors, especially low-density lipoprotein (LDL) cholesterol, is the cornerstone of preventing atherosclerotic coronary artery disease. Despite reducing LDL cholesterol, there remains a significant risk of cardiovascular disease. Inflammatory and metabolic pathways contribute to recurrence of cardiovascular events, and are often missed in clinical practice. Eicosapentaenoic acid (EPA) may play a crucial role in reducing residual risk of cardiovascular disease. In this review we discuss the clinical applications of omega-3 fatty acids (OM3FAs), their mechanism of action, the difference between pure EPA and docosahexaenoic acid components, and the latest cardiovascular outcome trials and imaging trials evaluating coronary plaque. PubMed and EMBASE were searched to include all the remarkable clinical trials investigating OM3FAs and cardiovascular disease. Beyond statins, additional medications are required to reduce the risk of cardiovascular disease. EPA has shown cardiovascular benefit in addition to statins in large outcome trials. Additionally, multiple serial-imaging studies have demonstrated benefits on plaque progression and stabilization. Due to its pleotropic properties, icosapent ethyl outperforms other OM3FAs in decreasing cardiovascular disease risk in both patients with and without high triglycerides, and is currently recommended as an adjunct to statins. To further strengthen the current evidence, additional research is required to elucidate the inconsistencies between the effects of pure EPA and EPA plus docosahexaenoic acid.

Effects of ω-3 Polyunsaturated Fatty Acids on Coronary Atherosclerosis and Inflammation: A Systematic Review and Meta-Analysis

Background and Purpose

Multiple guidelines suggest the ω-3 polyunsaturated fatty acids (ω-3 PUFAs) help to prevent major vascular events of coronary heart disease (CHD), but the data on large trials of ω-3 fatty acids are controversial. We reviewed the available evidence to determine the effect of ω-3 PUFAs on coronary atherosclerosis.

Materials and Methods

Literature were from online databases. Randomized controlled trials (RCTs) or observational studies were acceptable. Quantitative data synthesis was conducted using R version 4.1.2. Each outcome was calculated using standardized mean difference (SMD) in a random-effect model. Sensitivity analysis was conducted for each outcome. A total of 21 RCTs and 1 observational study with 2,277 participants were included.

Results

Meta-analysis indicated a benefit of ω-3 PUFAs on coronary atherosclerosis, namely, (1) ω-3 PUFAs can reduce the atherosclerotic plaque volume (SMD −0.18; 95% CI −0.31 to −0.05); (2) ω-3 PUFAs can help reduce the loss of the diameter of the narrowest segments of coronary arteries in patients with CHD (SMD 0.29; 95% CI, 0.05–0.53); (3) ω-3 PUFAs do not have significant effect on volume of lipid plaque in coronary arteries (SMD −1.18; 95% CI −2.95 to 0.58), volume of fiber plaque (SMD 0.26; 95% CI −0.81 to 1.33), and calcified plaque (SMD 0.17; 95% CI −0.55 to 0.89); and (4) ω-3 PUFAs had no significant effect on endothelial inflammatory factors in peripheral blood.

Conclusions

We confirmed that ω-3 PUFAs benefit patients with CHD by reducing the progression of coronary atherosclerosis. We indicated that the benefits were not caused by reducing endothelial inflammations of coronary arteries.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021285139, identifier: CRD42021285139.

Achieving coronary plaque regression: a decades-long battle against coronary artery disease

INTRODUCTION

Traditionally atherosclerosis was thought to be progressive and medical treatment solely focused on delaying the progression of atherosclerosis rather than treating the disease itself. Multiple recent studies, however, have demonstrated a significant decrease in cardiovascular mortality with the use of additional anti-atherosclerotic therapies beyond statins. Consistent with these observations, mechanistic studies indicate that these additional anti-atherosclerotic therapies have a positive effect on both halting and reversing the course of atherosclerosis.

AREAS COVERED

We examine the progression of atherosclerosis and the efficacy of various anti-atherosclerotic treatment classes in this review utilizing multimodality imaging techniques. Searches were conducted in electronic databases: PubMed and EMBASE for all peer reviewed publications that examined coronary plaque progression, regression and stabilization using different imaging modalities and antiatherosclerosis therapies. The keywords coronary plaque, coronary angiography, IVUS, intravascular OCT, CCTA in conjunction with the various therapies included in this review were searched in different combinations. All relevant published articles on this topic were identified and their reference lists were screened for relevance.

EXPERT COMMENTARY

Though lipoprotein levels have traditionally been the target for antiatherosclerosis medication, several newer strategies have emerged creating novel targets in the treatment of coronary atherosclerosis. Using a combination of antiatherosclerosis therapies in conjunction with noninvasive imaging modalities like CCTA to directly visualize the plaque, is currently the focus of the future, with the aim of preventing and reversing atherosclerosis.

Reducing residual cardiovascular risk in Europe: Therapeutic implications of European medicines agency approval of icosapent ethyl/eicosapentaenoic acid

Atherosclerotic cardiovascular disease (ASCVD) and its atherothrombotic complications impose a substantial disease burden in Europe, representing a cost of €210 billion per year for the European Union. Hypertriglyceridemia, a major risk factor for premature ASCVD, is present in more than 20% of the European population, and is a key feature of atherogenic dyslipidemia. Recent findings from the Progression of Early Subclinical Atherosclerosis (PESA) cohort in Spain showed that even in apparently healthy, middle-aged individuals without a history of cardiovascular (CV) risk, elevated triglyceride levels are associated with subclinical atherosclerosis and arterial inflammation. Emerging evidence from epidemiologic and genetic studies supports an independent causative role of triglycerides, triglyceride-rich lipoproteins, and their remnants in this pathology. Icosapent ethyl (IPE) is a highly purified, stable ethyl ester of eicosapentaenoic acid (EPA) that was initially approved by the United States Food and Drug Administration to treat severe hypertriglyceridemia, and subsequently received an expanded indication to reduce the risk of CV events in adult statin-treated patients. Approval was based on the pivotal, randomized, placebo-controlled, double-blind Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT), which showed that high-dose IPE (4 g/day) significantly reduced the risk of primary and secondary composite endpoints comprising major CV events and CV death relative to placebo. In 2021, the European Medicines Agency (EMA) approved IPE to reduce the risk of CV events in adult statin-treated patients at high CV risk with elevated triglyceride levels (≥1.7 mmol/L [≥150 mg/dL]) and established CV disease, or diabetes and at least one other CV risk factor. Clinical studies in Europe, which included patients with acute myocardial infarction, coronary artery disease, and those undergoing cardiac rehabilitation, established that 12.5% to 23.3% of these high-risk populations may benefit from treatment with IPE. Such clinical benefit may in part result from the moderate triglyceride-lowering properties of IPE/EPA; equally however, concentrations of atherogenic remnant particle-cholesterol are markedly reduced. Furthermore, IPE/EPA exerts pleiotropic actions beyond its lipid-lowering properties, which include modulation of endothelial function, attenuation of intra-plaque inflammation and oxidative stress, and reduction in macrophage accumulation. Plasma phospholipids, into which EPA is primarily incorporated and transported, appear to serve as precursors for a series of anti-inflammatory metabolites involving the resolvins RvE1 to RvE3, a pathway which may confer cardioprotective benefits. In addition, plaque imaging data from the Effect of Icosapent Ethyl on Progression of Coronary Atherosclerosis in Patients With Elevated Triglycerides on Statin Therapy (EVAPORATE) and the Combination Therapy of Eicosapentaenoic Acid and Pitavastatin for Coronary Plaque Regression Evaluated by Integrated Backscatter Intravascular Ultrasonography (CHERRY) trials show that plaque stabilization may be favorably affected. These factors may act synergistically to stabilize atherosclerotic plaques and reduce CV risk. In addition to robust efficacy data, multiple cost-utility studies across several countries indicate that IPE/EPA is a cost-effective treatment option that is favorably situated relative to some common willingness-to-pay thresholds. This review will evaluate the relevance of hypertriglyceridemia to residual ASCVD burden in statin-treated dyslipidemic patients, the potential of IPE/EPA to reduce the risk of ASCVD and cardiovascular mortality in high-risk patient populations, and the mechanisms which may underlie these effects. Finally, the clinical implications of the EMA label for IPE will be critically appraised in light of the updated 2019 European Society of Cardiology/European Atherosclerosis Society guidelines on the management of dyslipidemia and the recent European Atherosclerosis Society consensus statement on triglyceride-rich lipoproteins and their remnants, together with considerations of its cost-effectiveness across several countries.

Prognostic Value of Serial Coronary CT Angiography in Atherosclerotic Plaque Modification: What have we learnt?

Purpose of review

To provide an update and to outline the status of coronary computer tomography angiography (CCTA) in evaluation of coronary plaques and discuss the relevance of serial CCTA in guiding cardiovascular risk stratification and anti- atherosclerotic medical therapy.

Recent Findings

Coronary CTA is now the imaging modality of choice in monitoring changes in coronary plaque. It has been used in innumerable clinical trials which have demonstrated the benefits of several therapeutic agents and has excellent correlation with previously used invasive imaging modalities. It is safe, fast, less cumbersome, and a cost-effective testing method compared to other invasive imaging modalities for coronary plaque analysis.

Summary

The emergence of a noninvasive imaging modality such as CCTA, now permits quantification not only of plaque burden but also allows for further distinction of plaque components and identification of vulnerable plaques. Application of these findings continues to extend the prospect of coronary CTA in evaluation and management of atherosclerotic coronary artery disease (CAD) in clinical practice. In the future artificial intelligence and machine learning will play a significant role in plaque analysis allowing for high accuracy and reproducibility which will lead to a substantial increase in the utilization of coronary CTA.

Multimodality Imaging Trials Evaluating the Impact of Omega-3 Fatty Acids on Coronary Artery Plaque Characteristics and Burden

Treatment of established risk factors, especially low-density lipoprotein (LDL) cholesterol, is the cornerstone of preventing atherosclerotic coronary artery disease. Despite reducing LDL cholesterol, there remains a significant risk of cardiovascular disease. Inflammatory and metabolic pathways contribute to recurrence of cardiovascular events, and are often missed in clinical practice. Eicosapentaenoic acid (EPA) may play a crucial role in reducing residual risk of cardiovascular disease. In this review we discuss the clinical applications of omega-3 fatty acids (OM3FAs), their mechanism of action, the difference between pure EPA and docosahexaenoic acid components, and the latest cardiovascular outcome trials and imaging trials evaluating coronary plaque. PubMed and EMBASE were searched to include all the remarkable clinical trials investigating OM3FAs and cardiovascular disease. Beyond statins, additional medications are required to reduce the risk of cardiovascular disease. EPA has shown cardiovascular benefit in addition to statins in large outcome trials. Additionally, multiple serial-imaging studies have demonstrated benefits on plaque progression and stabilization. Due to its pleotropic properties, icosapent ethyl outperforms other OM3FAs in decreasing cardiovascular disease risk in both patients with and without high triglycerides, and is currently recommended as an adjunct to statins. To further strengthen the current evidence, additional research is required to elucidate the inconsistencies between the effects of pure EPA and EPA plus docosahexaenoic acid.

Lesion Geometry as Assessed by Optical Coherence Tomography Is Related to Myocardial Ischemia as Determined by Cardiac Magnetic Resonance Imaging

INTRODUCTION

Although the relationship between the geometry of coronary stenosis and the presence of myocardial ischemia is well known, the association between stenosis geometry and severity and/or extent of ischemia is still unexplored. Thus, we investigated this relationship using optical coherence tomography (OCT) to assess stenosis parameters and cardiac magnetic resonance imaging (CMR) to determine both extent and severity of ischemia.

METHODS

We analyzed 55 lesions from 51 patients with stable angina. Pre-interventionally, all patients underwent OCT-analysis of stenosis morphology as well as CMR to determine both the extent and severity of myocardial ischemia.

RESULTS

Percent area stenosis (%AS) was significantly associated with ischemic burden (r = 0.416, p = 0.003). Similar results could be obtained for other stenosis parameters as well as for several other parameters assessing the extent of ischemia. Furthermore, OCT-derived stenosis parameters were associated with the product of ischemic burden and severity of ischemia (%AS: r = 0.435, p = 0.002; similar results for other parameters). A Poiseuille's-law-modelled combination of stenosis length and minimal lumen diameter yielded a good diagnostic efficiency (AUC 0.787) in predicting an ischemic burden >10%.

CONCLUSIONS

Our data highlight the key role of the geometry of coronary lesions in determining myocardial ischemia.

Meta-Analysis Comparing the Effect of Combined Omega-3 + Statin Therapy Versus Statin Therapy Alone on Coronary Artery Plaques

Statin therapy plays an important role in stabilizing and regressing coronary artery plaques. Omega-3 supplements also have anti-inflammatory and antioxidant effects on coronary plaques. However, the effect of omega-3 supplementation on the basis of statin therapy on the stability and composition of plaques, is still unclear. We searched for randomized controlled trials published prior to November 2020 in the PubMed, Embase and Cochrane databases. Finally, eight studies using different imaging techniques to evaluate coronary atherosclerotic plaque, including optical coherence tomography (OCT), coronary CT angiography (cCTA) and intravascular ultrasound (IB-IVUS), met our inclusion criteria. We pooled data extracted from the included studies using the standardized mean difference (SMD) or mean difference (MD) of the random effects model. Compared with statin treatment alone, the combined treatment further delayed the progression of total plaque volume [SMD -0.36, 95% confidence interval (CI) -0.64 to -0.08, p = 0.01] and fiber content (SMD -0.40, 95% CI -0.68 to -0.13, p = 0.004). The plasma high-sensitivity C-reactive protein (hs-CRP) level of patients in the combination treatment group was significantly lower than that of the patients in the statin treatment group alone (SMD -0.30, 95% CI -0.59 to -0.01, p = 0.04). In addition, the combined use of omega-3 further increases the fibrous cap thickness (FCT) of the plaque with an MD of 29.45 μm. There were no significant differences in plasma high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), or lipid content in plaques between the two groups. Omega-3 combined with statins is superior to the statin treatment group in stabilizing and promoting coronary plaque regression and may help to further reduce the occurrence of cardiovascular events.

Omega-3 Fatty Acids and Coronary Artery Disease: More Questions Than Answers

Studies show that patients with elevated triglycerides and well-controlled LDL levels under statin therapy still have a significant residual risk of cardiovascular (CV) events. Despite many attempts to reduce triglycerides with different hypolipidemic drugs, no therapeutic option has given satisfactory results so far. The initial enthusiasm that omega-3 fatty acids can effectively reduce triglycerides and CV risk was replaced with skepticism when the first large clinical trials failed to show any benefit in primary or secondary prevention. However, the latest studies succeeded in showing a positive effect of omega-3 fatty acids on CV outcome in patients with hypertriglyceridemia. The largest benefit was reported in secondary but not primary prevention. Interestingly, the reduction in triglycerides in some of these studies was disproportionately low to the relatively high CV risk reduction, which could indicate some other effects of omega-3 fatty acids that go well beyond hypotriglyceridemic action. This includes blood pressure reduction, antithrombotic effect, improvement of inflammatory status, endothelial function, and insulin resistance. Investigations also reported a significant and positive influence of omega-3 fatty acids on the composition and stabilization of coronary atherosclerotic plaques in patients with and without previous CV events. In addition to insufficiently known mechanisms of action and conflicting results about the effectiveness of omega-3 fatty acids, the safety problems, which include increased prevalence of atrial fibrillation and hemorrhage, were also reported. The aim of this clinical review was to summarize the current knowledge regarding the use of omega-3 fatty acids in CV patients, particularly those with coronary artery disease, and to present an overview of key clinical trial data.