Coronary atheroma regression and adverse cardiac events: A systematic review and meta-regression analysis

Strategies to improve cardiovascular health and treatment of dyslipidemia in Spain. Expert Insights Project

OBJECTIVES

To gather opinions, recommendations, and proposals for improvement from Spanish clinicians on cardiovascular (CV) health, with particular focus on dyslipidemia management.

METHODS

The Expert Insights project involved 8face-to-face sessions held throughout Spain, attended by 138 CV health experts. Clinicians answered to 25 questions survey related to CV health and dyslipidemia control. Each session included an analysis and a discussion on the perceived realities and areas for improvement.

RESULTS

72% of centers have a standardized process for monitoring patients after a CV episode at discharge, but only 37% during their clinical follow-up. Patient care and management are dependent on the physician, with a lack of coordination between hospital specialties and primary care (PC). 95% of clinicians believe it is necessary to standarize treatment optimization. 65% of centers prescribe combined lipid-lowering treatment after a CV episode. Updating cLDL levels in the Therapeutic Positioning Report and standardizing and globalizing the prescription document would reduce iPCSK9 prescription barriers and lead to more equitable access.

CONCLUSIONS

In Spain, there are significant deficiencies in the management of dyslipidemia, with a great need for a consensus on standardizing management processes and optimizing patient treatment. The opinions, recommendations, and improvement proposals from Spanish clinicians on CV health are an important starting point to improve the situation.

The clinical relevance of the reversal of coronary atherosclerotic plaque

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of death globally despite advances in preventive therapies. Understanding of the initiation and progression of atherosclerosis, the interplay between lipoproteins, endothelial dysfunction, inflammation, and immune responses is critical to treating this disease. The development of vulnerable coronary plaques prone to thrombosis, can lead to acute coronary syndromes, for these reasons, the potential plaque stabilization and regression through pharmacological interventions, particularly lipid-lowering agents like statins and PCSK9 inhibitors is crucial. The imaging techniques such as intravascular ultrasound (IVUS), near-infrared spectroscopy (NIRS), and optical coherence tomography (OCT) play a key role in assessing plaque composition and guiding interventional therapeutic strategies. Clinical evidence supports the efficacy of intensive lipid-lowering therapy in inducing plaque regression, with studies demonstrating reductions in plaque volume and improvements in plaque morphology assessed by IVUS, OCT and NIRS. While pharmacological interventions show promise in promoting plaque regression and stabilization, their impact on long-term cardiovascular events requires further investigation. Multimodality imaging and comprehensive outcome trials are proposed as essential tools for elucidating the relationship between plaque modification and clinical benefit in coronary atherosclerosis. The stabilization or regression of atherosclerotic plaque might serve as the phenomenon linking the reduction in LDL-C levels to the decrease in cardiovascular events. Overall, this review emphasizes the ongoing efforts to advance our understanding of ASCVD pathophysiology and optimize therapeutic approaches for improving patient outcomes.

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.

Regression and stabilization of atherogenic plaques

Atherosclerotic plaque assessment has become a crucial element in the examination of cardiovascular diseases. Plaque may exhibit progression and could become unstable if not treated, making plaque regression and stabilization among the most important goals of any cardiovascular intervention in cardiovascular medicine. In this review, we explore the current understanding of plaque regression and stabilization, discuss imaging and measurement techniques, and examine the evidence for pharmacological interventions and other interventions aimed at addressing this condition.

Effect of combining evolocumab with statin on carotid intraplaque neovascularization in patients with premature coronary artery disease (EPOCH)

BACKGROUND AND AIMS

We aimed to explore the effect of PCSK9 inhibitor based on the background of statin on carotid intraplaque neovascularization (IPN) assessed by serial contrast-enhanced ultrasound (CEUS) analysis in Chinese patients with premature coronary artery disease (PCAD).

METHODS

41 patients were included to receive treatments with biweekly evolocumab (n = 22) or placebo (n = 19) in addition to statin therapy for 52 weeks. All patients were newly diagnosed with PCAD and treatments were initiated at baseline of the observations. Baseline and 52-week CEUS were acquired to measure the max plaque height (MPH) and IPN. The primary outcome was the 52-week IPN changes, the secondary endpoints included the 52-week MPH changes and major adverse cardiovascular events.

RESULTS

The mean ± SD age of the participants was 46.76 ± 8.56 years, and 61% (25/41) of patients were on statins before the start of the study. There was no statistically significant difference in the history of statins treatment and the initiated lipid-lowering therapy of atorvastatin and rosuvastatin between groups (p > 0.05). At 52 weeks, the evolocumab group showed a lower LDL level (0.84 ± 0.45 mmol/L vs. 1.58 ± 0.51 mmol/L, p < 0.001) and a greater decrease in percent reduction of LDL-C level (-65% vs. -32%) and a higher percent of achieving lipid-lowering target (95% vs. 53%, p < 0.05) compared with the placebo group. At 52 weeks, IPN (evolocumab group: 0.50 ± 0.60 vs. 1.50 ± 0.80, p < 0.001; placebo group: 0.79 ± 0.54 vs. 1.26 ± 0.65, p < 0.05) and MPH (evolocumab group: 2.01 ± 0.44 mm vs. 2.57 ± 0.90 mm, p < 0.05, placebo group: 2.21 ± 0.58 mm vs. 2.92 ± 0.86 mm, p < 0.05) reduced significantly in both groups from baseline to 52-week follow-up. IPN and MPH were decreased by both treatments. Still, there was no significant difference in delta (52 weeks - baseline) MPH by an ANOVA analysis between the two groups [evolocumab group: -0.56 mm (2.01 mm-2.57 mm); placebo group: -0.71 mm (2.21 mm-2.92 mm), p > 0.05]. In the evolocumab group, the change in the mean reduction of IPN from baseline [-1.00 (0.50-1.50) vs. -0.47 (0.79-1.26), p < 0.05] and the incidence of patients with carotid IPN decrease were significantly greater reduction (90% vs. 58%, p < 0.05).

CONCLUSIONS

If compared to placebo, the PCSK9 inhibitor evolocumab combined with statins resulted in a greater decrease in LDL-C and plaque neovascularization in Chinese patients with PCAD.

Cardiovascular prevention in diabetes mellitus. Is it appropriate to speak of moderate or intermediate risk?

Diabetes, especially type 2, is considered a risk situation for atherosclerotic cardiovascular disease (ASCVD). Subjects with diabetes type 2 have a mortality rate due to ASCVD 3 times higher than that found in the general population, attributed to hyperglycemia and the frequent association of other cardiovascular risk factors, such as atherogenic dyslipidemia. Numerous scientific societies have established a risk classification for ASCVD in diabetes based on 3 degrees (moderate, high and very high). The objectives of dyslipidemia control are clearly defined and accepted, and vary depending on the previously established cardiovascular risk. In moderate or intermediate risk, the guidelines propose a less intensive intervention, maintaining LDL-C levels<100mg/dL and NO-HDL-C levels<130mg/dL, and waiting 10 years until reaching the high-risk category to initiate more intensive treatment. However, during the decade of follow-up recommended in the guidelines, cholesterol deposition in the arterial wall increases, facilitating the development of an unstable and inflammatory atheromatous plaque, and the development of ASCVD. Alternatively, diabetes could be considered from the outset to be a high-risk situation and the goal should be LDL-C<70mg/dL. Furthermore, maintaining LDL-C levels<70mg/dL contributes to reducing and stabilizing atheromatous plaque, avoiding or reducing mortality episodes due to ASCVD during those years of diabetes evolution. Should we maintain the proposed objectives in subjects with diabetes and moderate risk for a decade until reaching the high cardiovascular risk phase or, on the contrary, should we adopt a more intensive stance from the beginning seeking to reduce cardiovascular risk in the majority of patients with diabetes? Is it better to wait or prevent with effective therapeutic measures from the first moment?

Eradicating Atherosclerotic Events by Targeting Early Subclinical Disease: It Is Time to Retire the Therapeutic Paradigm of Too Much, Too Late

Recent decades have seen spectacular advances in understanding and managing atherosclerotic cardiovascular disease, but paradoxically, clinical progress has stalled. Residual risk of atherosclerotic cardiovascular disease events is particularly vexing, given recognized lifestyle interventions and powerful modern medications. Why? Atherosclerosis begins early in life, yet clinical trials and mechanistic studies often emphasize terminal, end-stage plaques, meaning on the verge of causing heart attacks and strokes. Thus, current clinical evidence drives us to emphasize aggressive treatments that are delayed until patients already have advanced arterial disease. I call this paradigm "too much, too late." This brief review covers exciting efforts that focus on preventing, or finding and treating, arterial disease before its end-stage. Also included are specific proposals to establish a new evidence base that could justify intensive short-term interventions (induction-phase therapy) to treat subclinical plaques that are early enough perhaps to heal. If we can establish that such plaques are actionable, then broad screening to find them in early midlife individuals would become imperative-and achievable. You have a lump in your coronaries! can motivate patients and clinicians. We must stop thinking of a heart attack as a disease. The real disease is atherosclerosis. In my opinion, an atherosclerotic heart attack is a medical failure. It is a manifestation of longstanding arterial disease that we had allowed to progress to its end-stage, despite knowing that atherosclerosis begins early in life and despite the availability of remarkably safe and highly effective therapies. The field needs a transformational advance to shift the paradigm out of end-stage management and into early interventions that hold the possibility of eradicating the clinical burden of atherosclerotic cardiovascular disease, currently the biggest killer in the world. We urgently need a new evidence base to redirect our main focus from terminal, end-stage atherosclerosis to earlier, and likely reversible, human arterial disease.

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.

'Super Rehab': can we achieve coronary artery disease regression? A feasibility study protocol

INTRODUCTION

Patients diagnosed with coronary artery disease (CAD) are currently treated with medications and lifestyle advice to reduce the likelihood of disease progression and risk of future major adverse cardiovascular events (MACE). Where obstructive disease is diagnosed, revascularisation may be considered to treat refractory symptoms. However, many patients with coexistent cardiovascular risk factors, particularly those with metabolic syndrome (MetS), remain at heightened risk of future MACE despite current management.Cardiac rehabilitation is offered to patients post-revascularisation, however, there is no definitive evidence demonstrating its benefit in a primary prevention setting. We propose that an intensive lifestyle intervention (Super Rehab, SR) incorporating high-intensity exercise, diet and behavioural change techniques may improve symptoms, outcomes, and enable CAD regression.This study aims to examine the feasibility of delivering a multicentre randomised controlled trial (RCT) testing SR for patients with CAD, in a primary prevention setting.

METHODS AND ANALYSIS

This is a multicentre randomised controlled feasibility study of SR versus usual care in patients with CAD. The study aims to recruit 50 participants aged 18-75 across two centres. Feasibility will be assessed against rates of recruitment, retention and, in the intervention arm, attendance and adherence to SR. Qualitative interviews will explore trial experiences of study participants and practitioners. Variance of change in CAD across both arms of the study (assessed with serial CT coronary angiography) will inform the design and power of a future, multi-centre RCT.

ETHICS AND DISSEMINATION

Ethics approval was granted by South West-Frenchay Research Ethics Committee (reference: 21/SW/0153, 18 January 2022). Study findings will be disseminated via presentations to relevant stakeholders, national and international conferences and open-access peer-reviewed research publications.

TRIAL REGISTRATION NUMBER

ISRCTN14603929.

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.

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.

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.

Effect of Evolocumab on Coronary Plaque Phenotype and Burden in Statin-Treated Patients Following Myocardial Infarction

OBJECTIVES

The purpose of this study was to determine the effect of evolocumab on optical coherence tomography (OCT) measures of plaque composition.

BACKGROUND

The proprotein convertase subtilisin kexin type-9 inhibitor evolocumab produced coronary atheroma regression in statin-treated patients.

METHODS

Patients with a non-ST-segment elevation myocardial infarction were treated with monthly evolocumab 420 mg (n = 80) or placebo (n = 81) for 52 weeks. Patients underwent serial OCT and intravascular ultrasound imaging within a matched arterial segment of a nonculprit vessel. The primary analysis determined the change in the minimum fibrous cap thickness and maximum lipid arc throughout the imaged arterial segment. Additional analyses determined changes in OCT features in lipid-rich plaque regions and plaque burden. Safety and tolerability were evaluated.

RESULTS

Among treated patients, (age 60.5 ± 9.6 years; 28.6% women; low-density lipoprotein cholesterol [LDL-C], 141.3 ± 33.1 mg/dL), 135 had evaluable imaging at follow-up. The evolocumab group achieved lower LDL-C levels (28.1 vs 87.2 mg/dL; P < 0.001). The evolocumab group demonstrated a greater increase in minimum fibrous cap thickness (+42.7 vs +21.5 μm; P = 0.015) and decrease in maximum lipid arc (-57.5^o vs. -31.4^o; P = 0.04) and macrophage index (-3.17 vs -1.45 mm; P = 0.04) throughout the arterial segment. Similar benefits of evolocumab were observed in lipid-rich plaque regions. Greater regression of percent atheroma volume was observed with evolocumab compared with placebo (-2.29% ± 0.47% vs -0.61% ± 0.46%; P = 0.009). The groups did not differ regarding changes in microchannels or calcium.

CONCLUSIONS

The combination of statin and evolocumab after a non-ST-segment elevation myocardial infarction produces favorable changes in coronary atherosclerosis consistent with stabilization and regression. This demonstrates a potential mechanism for the improved clinical outcomes observed achieving very low LDL-C levels following an acute coronary syndrome. (Imaging of Coronary Plaques in Participants Treated With Evolocumab; NCT03570697).

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.

Coronary Atherosclerotic Plaque Regression: JACC State-of-the-Art Review

Over the last 3 decades there have been substantial improvements in treatments aimed at reducing cardiovascular (CV) events. As these treatments have been developed, there have been parallel improvements in coronary imaging modalities that can assess plaque volumes and composition, using both invasive and noninvasive techniques. Plaque progression can be seen to precede CV events, and therefore, many studies have longitudinally assessed changes in plaque characteristics in response to various treatments, aiming to demonstrate plaque regression and improvements in high-risk features, with the rationale being that this will reduce CV events. In the past, decisions surrounding treatments for atherosclerosis have been informed by population-based risk scores for initiation in primary prevention and low-density lipoprotein cholesterol levels for titration in secondary prevention. If outcome data linking plaque regression to reduced CV events emerge, it may become possible to directly image plaque treatment response to guide management decisions.

The effects of lipid-lowering therapy on coronary plaque regression: a systematic review and meta-analysis

To assess the influence of lipid-lowering therapy on coronary plaque volume, and to identify the LDL and HDL targets for plaque regression to provide a comprehensive overview. The databases searched (from inception to 15 July 2020) to identify prospective studies investigating the impact of lipid-lowering therapy on coronary plaque volume and including quantitative measurement of plaque volume by intravascular ultrasound after treatment. Thirty-one studies that included 4997 patients were selected in the final analysis. Patients had significantly lower TAV (SMD: 0.123 mm³; 95% CI 0.059, 0.187; P = 0.000) and PAV (SMD: 0.123%; 95% CI 0.035, 0.212; P = 0.006) at follow-up. According to the subgroup analyses, TAV was significantly reduced in the LDL < 80 mg/dL and HDL > 45 mg/dL group (SMD: 0.163 mm³; 95% CI 0.092, 0.234; P = 0.000), and PAV was significantly reduced in the LDL < 90 mg/dL and HDL > 45 mg/dL group (SMD: 0.186%; 95% CI 0.081, 0.291; P = 0.001).Thirty-one studies that included 4997 patients were selected in the final analysis. Patients had significantly lower TAV (SMD: 0.123 mm³; 95% CI 0.059, 0.187; P = 0.000) and PAV (SMD: 0.123%; 95% CI 0.035, 0.212; P = 0.006) at follow-up. According to the subgroup analyses, TAV was significantly reduced in the LDL < 80 mg/dL and HDL > 45 mg/dL group (SMD: 0.163 mm³; 95% CI 0.092, 0.234; P = 0.000), and PAV was significantly reduced in the LDL < 90 mg/dL and HDL > 45 mg/dL group (SMD: 0.186%; 95% CI 0.081, 0.291; P = 0.001). Our meta-analysis suggests that not only should LDL be reduced to a target level of < 80 mg/dL, but HDL should be increased to a target level of > 45 mg/dL to regress coronary plaques.

Trial Registration PROSPERO identifier: CRD42019146170.

Nanoparticle-based "Two-pronged" approach to regress atherosclerosis by simultaneous modulation of cholesterol influx and efflux

Reduction of lipoprotein uptake by macrophages and stimulation of cholesterol efflux are two essential steps required for atherosclerotic plaque regression. We used the optimized mannose-functionalized dendrimeric nanoparticle (mDNP)-based platform for macrophage-specific delivery of therapeutics to simultaneously deliver SR-A siRNA (to reduce LDL uptake) and LXR ligand (LXR-L, to stimulate cholesterol efflux) - a novel "Two-pronged" approach to facilitate plaque regression. mDNP-mediated delivery of SR-A siRNA led to a significant reduction in SR-A expression with a corresponding decrease in uptake of oxLDL. Delivery of LXR-L increased expression of ABCA1/G1 and cholesterol efflux. Combined delivery of siRNA and LXR-L led to a significantly greater decrease in macrophage cholesterol content compared to either treatment alone. Administration of this in vitro optimized formulation of mDNP complexed with SR-A-siRNA and LXR-L (Two-pronged complex) to atherosclerotic LDLR-/- mice fed western diet (TD88137) led to significant regression of atherosclerotic plaques with a corresponding decrease in aortic cholesterol content.