Effect of combination of ezetimibe and a statin on coronary plaque regression in patients with acute coronary syndrome

Atherosclerotic plaque stabilization and regression: a review of clinical evidence

Atherosclerotic plaque results from a complex interplay between lipid deposition, inflammatory changes, cell migration and arterial wall injury. Over the past two decades, clinical trials utilizing invasive arterial imaging modalities, such as intravascular ultrasonography, have shown that reducing levels of atherogenic lipoproteins, mainly serum LDL-cholesterol (LDL-C), to very low levels can safely reduce overall atherosclerotic plaque burden and favourably modify plaque composition. Classically, this outcome has been achieved with intensive statin therapy. Since 2016, newer and potent lipid-lowering strategies, such as proprotein convertase subtilisin-kexin type 9 inhibition, have shown incremental effects on plaque regression and risk of clinical events. Despite maximal reduction in plasma LDL-C levels, considerable residual cardiovascular risk remains in some patients. Therefore, there is a need to study therapeutic approaches that address residual risk beyond LDL-C reduction to promote plaque stabilization or regression. Contemporary imaging modalities, such as coronary computed tomography angiography, enable non-invasive assessment of the overall atherosclerotic plaque burden as well as of certain local plaque characteristics. This technology could allow further study of plaque stabilization and regression using novel therapeutic approaches. Non-invasive plaque assessment might also offer the potential to guide personalized management strategies if validated for this purpose.

Management of Coronary Vulnerable Plaque With Medical Therapy or Local Preventive Percutaneous Coronary Intervention

Acute coronary syndromes (ACS) often result from the rupture or erosion of high-risk coronary atherosclerotic plaques (ie, vulnerable plaques). Advances in intracoronary imaging such as intravascular ultrasound, optical coherence tomography, or near-infrared spectroscopy have improved the identification of vulnerable plaques, characterized by large plaque burden, small minimal luminal area, thin fibrous cap, and large lipid content. Although pharmacology, including lipid-lowering agents, and intensive risk-factor control are pivotal for management of vulnerable plaques and secondary prevention, recurrent events tend to accrue despite intensive pharmacotherapy. Therefore, it has been hypothesized that local preventive percutaneous coronary intervention may passivate these vulnerable plaques, preventing the occurrence of plaque-related ACS. However, solid evidence is lacking on its use for treatment of non-flow-limiting vulnerable plaques. As such, the optimal management of vulnerable plaques has not been established. Herein, we have reviewed the diagnosis and management of vulnerable plaques, focusing on systematic pharmacology and focal treatments.

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.

Effect of ezetimibe-statin combination therapy vs. statin monotherapy on coronary atheroma phenotype and lumen stenosis in patients with coronary artery disease: a meta-analysis and trial sequential analysis

Background

Evidence indicates that the addition of ezetimibe to statin therapy reduces cardiovascular events. However, the impact of ezetimibe-statin combination therapy on coronary plaque regression, plaque stabilization, and diameter stenosis remains a matter of controversy.

Methods

We performed electronic searches in PubMed, Web of Knowledge, and the Cochrane Central Register of Controlled Trials to identify eligible trials assessing the effects of ezetimibe-statin combination therapy versus statin monotherapy reporting at least one outcome among total atheroma volume (TAV), minimum fibrous cap thickness (FCT), lumen volume (LV), and lumen area (LA) derived from intravascular imaging modalities of intravascular ultrasound (IVUS) and optical coherence tomography (OCT). We used the random-effects model and performed trial sequential analysis (TSA) during this meta-analysis.

Results

Eleven articles with a total of 926 individuals (460 in the dual-lipid-lowering therapy group and 466 in the statin monotherapy group) were included in the final meta-analysis. Compared to statin monotherapy, ezetimibe-statin combination therapy was associated with significantly decreased TAV [WMD = -3.17, 95% CI (-5.42 to -0.92), and p = 0.006], with no effect on the LV of the coronary artery [WMD = -0.52, 95% CI (-2.24 to 1.21), and p = 0.56], the LA of the coronary artery [WMD = 0.16, 95% CI (-0.10-0.42), and p = 0.22], or minimum FCT thickness [WMD = 19.11, 95%CI (-12.76-50.97)].

Conclusion

In patients with coronary artery disease, ezetimibe-statin combination therapy resulted in a significant regression in TAV compared to statin monotherapy, whereas no overall improvements of minimum FCT or lumenal stenosis were observed.

An Efficient, Simultaneous Electrochemical Assay of Rosuvastatin and Ezetimibe from Human Urine and Serum Samples

The drug combination of rosuvastatin (ROS) and ezetimibe (EZE) is used to treat hypercholesterolemia. In this work, a simultaneous electrochemical examination of ROS and EZE was conducted for the first time. The electrochemical determination of ROS and EZE was carried out using adsorptive stripping differential pulse voltammetry (AdSDPV) on a glassy carbon electrode (GCE) in 0.1 M H₂SO₄. The effects of the pH, scan rate, deposition potential, and time on the detection of ROS and EZE were analyzed. Under optimum conditions, the developed sensor exhibited a linear response between 1.0 × 10^-6 M and 2.5 × 10^-5 M for EZE and 5.0 × 10^-6 M, and 1.25 × 10^-5 M for ROS. The detection limits for ROS and EZE were 3.0 × 10^-7 M and 2.0 × 10^-6 M, respectively. The developed sensor was validated in terms of linear range, accuracy, precision, the limit of determination (LOD), and the limit of quantification (LOQ), and it was evaluated according to ICH Guidelines and USP criteria. The proposed method was also used to determine ROS and EZE in human urine and serum samples, which are reported in terms of recovery studies.

Additive effects of ezetimibe, evolocumab, and alirocumab on plaque burden and lipid content as assessed by intravascular ultrasound: A PRISMA-compliant meta-analysis

BACKGROUND

The additive effects of ezetimibe, evolocumab or alirocumab on lipid level, plaque volume, and plaque composition using intravascular ultrasound (IVUS) remain unclear.

METHODS

According to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement, we performed a systematic review and meta-analysis of trials assessing the effects of ezetimibe, evolocumab, and alirocumab on coronary atherosclerosis using IVUS. The primary outcome was change in total atheroma volume (TAV), and the secondary outcomes were changes and differences in plaque composition and lipid content.

RESULTS

Data were collected from 9 trials, involving 917 patients who received ezetimibe, evolocumab or alirocumab in addition to a statin and 919 patients who received statins alone. The pooled estimate demonstrated a significant reduction in TAV with the addition of ezetimibe and favorable effects of evolocumab and alirocumab on TAV. Subgroup analysis also supported favorable effects of evolocumab and alirocumab on TAV, according to baseline TAV, gender, type 2 diabetes mellitus, and prior stain use. Addition of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor to statin therapy resulted in significant reductions in low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglycerides (TG), but not in high-density lipoprotein cholesterol (HDL-C). The pooled estimate also showed significant favorable effects of ezetimibe on LDL-C, TC, and TG, but an insignificant effect on HDL-C. Patients who received ezetimibe showed similar changes in the necrotic core, fibro-fatty plaque, fibrous plaque, and dense calcification compared with patients not treated with ezetimibe.

CONCLUSIONS

The addition of ezetimibe to statin therapy may further reduce plaque and lipid burdens but may not modify plaque composition. Although current evidence supports a similar impact from the addition of PCSK9 inhibitors to statin therapy, more evidence is needed to confirm such an effect.

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.

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.

Role of non-statin lipid-lowering therapy in coronary atherosclerosis regression: a meta-analysis and meta-regression

BACKGROUND

Several studies have investigated the association between non-statin lipid-lowering therapy and regression of atherosclerosis. However, these studies were mostly small and their results were not always robust. The objectives were: (1) to define if a dual lipid-lowering therapy (statin + non-statin drugs) is associated with coronary atherosclerosis regression, estimated by intravascular ultrasound (IVUS); (2) to assess the association between dual lipid-lowering-induced changes in low density lipoprotein cholesterol (LDL-C) and non-high-density-lipoprotein cholesterol (non-HDL-C) levels and atherosclerosis regression.

METHODS

A meta-analysis including trials of non-statin lipid-lowering therapy, reporting LDL-C, non-HDL-C and total atheroma volume (TAV) with a minimum of 6 months of follow-up was performed. The primary endpoint was defined as the change in TAV measured from baseline to follow-up, comparing groups of subjects on statins alone versus combination of statin and non-statin drugs. The random-effects model and meta-regression were performed.

RESULTS

Eight eligible trials of non-statin lipid-lowering drugs (1759 patients) were included. Overall, the dual lipid-lowering therapy was associated with a significant reduction in TAV [- 4.0 mm3 (CI 95% -5.4 to - 2.6)]; I2 = 0%]. The findings were similar in the stratified analysis according to the lipid-lowering drug class (ezetimibe or PCSK9 inhibitors). In the meta-regression, a 10% decrease in LDL-C or non-HDL-C levels, was associated, respectively, with 1.0 mm3 and 1.1 mm3 regressions in TAV.

CONCLUSION

These data suggests the addition of ezetimibe or PCSK9 inhibitors to statin therapy results in a significant regression of TAV. Reduction of coronary atherosclerosis observed with non-statin lipid-lowering therapy is associated to the degree of LDL-C and non-HDL-C lowering. Therefore, it seems reasonable to achieve lipid goals according to cardiovascular risk and regardless of the lipid-lowering strategy used (statin monotherapy or dual treatment).

Effect of Alirocumab on Coronary Atheroma Volume in Japanese Patients With Acute Coronary Syndrome - The ODYSSEY J-IVUS Trial

BACKGROUND

In patients with acute coronary syndrome (ACS), alirocumab reduced the risk of recurring ischemic events. ODYSSEY J-IVUS assessed the effect of alirocumab on coronary atheroma volume in Japanese patients recently hospitalized with ACS and hypercholesterolemia, using intravascular ultrasound imaging analysis.Methods and Results:Patients (n=206) who at index ACS diagnosis either had low-density lipoprotein cholesterol (LDL-C) ≥2.59 mmol/L (≥100 mg/dL) despite stable statin therapy, or were not on statins with LDL-C levels above target after statin initiation, were randomized (1:1) to alirocumab (75 mg every 2 weeks [Q2 W]/up to 150 mg Q2 W), or standard of care (SoC; atorvastatin ≥10 mg/day or rosuvastatin ≥5 mg/day) for 36 weeks. The primary efficacy endpoint (week [W] 36 mean [standard error] percent change in normalized total atheroma volume [TAV] from baseline) was -3.1 (1.0)% with SoC vs. -4.8 (1.0)% with alirocumab (between-group difference: -1.6 [1.4]; P=0.23). W36 absolute change from baseline in percent atheroma volume was -1.3 (0.4)% (SoC) and -1.4 (0.4)% (alirocumab; nominal P=0.79). At W36, LDL-C was reduced from baseline by 13.4% (SoC) vs. 63.9% (alirocumab; nominal P<0.0001). In total, 61.8% (SoC) and 75.7% (alirocumab) of patients reported treatment-emergency adverse events.

CONCLUSIONS

In Japanese patients with ACS and hypercholesterolemia inadequately controlled despite statin therapy, from baseline to W36, a numerically greater percent reduction in normalized TAV was observed with alirocumab vs. SoC, which did not reach statistical significance.

The Goal of Achieving Atherosclerotic Plaque Regression with Lipid-Lowering Therapy: Insights from IVUS Trials

Enormous effort has been put into the prevention of atherosclerosis through risk modification, especially with lipid-lowering therapies. Regression, that is, the reversal of the atherosclerosis process, has long been a goal of atherosclerosis research among basic and clinical investigators. Intravascular ultrasound (IVUS) was developed in the 1990s as an intracoronary imaging technique to observe the details of the vessel walls and to measure the vessel lumen and plaque area with high reproducibility. Compared with the coronary angiogram, IVUS provides far more detailed information on the vessel wall. In this article, we review lipid-lowering trials that have used IVUS and discuss the current understanding of the effectiveness of aggressive lipid-lowering therapy, which inhibits atherosclerotic progression and induces regression and plaque stabilization.

The effect of combined ezetimibe and statin therapy versus statin therapy alone on coronary plaque volume assessed by intravascular ultrasound: A systematic review and meta-analysis

BACKGROUND

Current guidelines recommend an intensive lipid-lowering therapy to achieve the low-density lipoprotein cholesterol (LDL-C) target in patients with high risk of cardiovascular disease. Former studies suggested adding ezetimibe to statin therapy in the above setting may promote plaque changes; however, this effect has not been consistently reported.

METHODS

Electronic searches were performed in MEDLINE, EMBASE, and Cochrane library on November 30, 2017 to identify prospective trials assessing the effects of combined ezetimibe and statin therapy versus statin therapy alone on atheroma volume using intravascular ultrasound. The effect size between treatment groups within individual studies was assessed by weighted mean difference (MD) using a random-effects model.

RESULTS

Eight studies were obtained for systematic review and 6 of them compromising total of 583 subjects that meet the criteria were meta-analyzed. There was a significant reduction from baseline to follow-up in total atheroma volume with an MD of -3.71 mm³ (95% confidence interval: -5.98 to -1.44, P < .001), whereas analysis for percent atheroma volume demonstrated weighted MD of - 0.77% (-1.68 to 0.14, P = .10). A substantial decrease in LDL-C was observed with MD -16.75 mg/dL (-20.89 to -12.60, P < .00001).

CONCLUSION

The addition of ezetimibe to statin therapy is effective in reducing total atheroma volume assessed by intravascular ultrasound and also resulted in effective reduction of plasma LDL-C levels.

Effect of alirocumab on coronary atheroma volume in Japanese patients with acute coronary syndromes and hypercholesterolemia not adequately controlled with statins: ODYSSEY J-IVUS rationale and design

BACKGROUND

Serial intravascular ultrasound (IVUS) imaging can be used to evaluate the effect of cholesterol-lowering on coronary atheroma progression and plaque volume, with evidence of potential incremental effects with more aggressive lipid-lowering treatments. Alirocumab is a highly specific, fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9). This study will investigate the effect of alirocumab on coronary artery plaque volume in Japanese patients with a recent acute coronary syndrome (ACS) and hypercholesterolemia while on stable statin therapy.

METHODS

ODYSSEY J-IVUS is a phase IV, open-label, randomized, blinded IVUS analysis, parallel-group, multicenter study in Japanese adults recently hospitalized for an ACS and who have elevated low-density lipoprotein cholesterol (LDL-C) values [≥100mg/dL (2.6mmol/L)] at ACS diagnosis and suboptimal LDL-C control on stable statin therapy. Patients will be randomized (1:1) to receive alirocumab or standard-of-care (SOC). The alirocumab arm will receive alirocumab 75mg every 2 weeks (Q2W) added to statin therapy (atorvastatin ≥10mg/day or rosuvastatin ≥5mg/day), with a dose increase to 150mg Q2W in patients whose LDL-C value remains ≥100mg/dL at week 12. The SOC arm will receive atorvastatin ≥10mg/day or rosuvastatin ≥5mg/day, with dose adjustment to achieve LDL-C <100mg/dL. Post-treatment IVUS imaging will be done at week 36±2. The primary objective is to compare the effect of alirocumab versus SOC on coronary atheroma progression (percent change in normalized total atheroma volume) after 9 months of treatment.

CONCLUSION

ODYSSEY J-IVUS will provide insights into the effect of alirocumab on coronary atherosclerotic plaque volume in patients with a recent ACS and hypercholesterolemia while on stable statin therapy. ClinicalTrials.gov number: NCT02984982.

Exploration into lipid management and persistent risk in patients hospitalised for acute coronary syndrome in Japan (EXPLORE-J): protocol for a prospective observational study

INTRODUCTION

The present study is the largest registry study ever conducted in Japan exploring the prevalence of familial hypercholesterolaemia (FH) among patients with acute coronary syndrome (ACS). Our study aims to (1) evaluate the status of lipid management and the subsequent risk of major cardiovascular events following hospitalisation of Japanese patients with ACS in real-world clinical practice; (2) determine the proportion of Japanese patients with ACS who achieve the lipid management goal and have a reduction of event risks with strict lipid management (low-density lipoprotein-cholesterol <1.81 mmol/L); (3) determine the prevalence of FH and (4) investigate the clinical significance of proprotein convertase subtilisin kexin 9 (PCSK9) level.

METHODS AND ANALYSIS

We will conduct a multicentre, prospective, observational study of approximately 2000 Japanese patients with ACS with/without FH hospitalised between April 2015 and August 2016. The primary end point is the incidence of major adverse cardiovascular events (MACEs) after initial hospitalisation. The secondary end points are (1) MACE developed from visit 1 to visit 2 (day 30); (2) MACE developed from visit 2 (day 30) to visit 5 (day 730); (3) treatment rate by lipid-lowering therapies (any statin or intensive, PCSK9 inhibitor, fibrates and ezetimibe); (4) incidence of events by the addition of the following outcomes to the primary end point: coronary revascularisation due to myocardial ischaemia, revascularisation other than coronary artery, inpatient treatment for occurrence or exacerbation of heart failure, transient ischaemic attack, acute arterial occlusion, central retinal artery occlusion and other adverse events prolonging or requiring hospitalisation and (5) proportion of subjects achieving target lipid levels.

ETHICS AND DISSEMINATION

The study protocol was submitted to the ethical review committee of each participating centre for approval. Participation in the study is voluntary and anonymous. The study findings will be disseminated in international peer-reviewed journals and presented at relevant conferences.

CLINICAL TRIAL REGISTRATION

UMIN000018946.

Ezetimibe/statin combination therapy to treat patients with type 2 diabetes

Patients with diabetes represent a population at higher risk for cardiovascular disease. Diabetic dyslipidemia is characterized by the so-called atherogenic lipid triad, consisting of an increase in small dense low density lipoprotein particles and in triglyceride-rich lipoproteins, and a decrease in high-density lipoprotein cholesterol, with an increase in non-HDL cholesterol. Numerous trials have investigated the efficacy of add-on ezetimibe therapy for patients with type 2 diabetes and not controlled by statin therapy. The published data highly suggest that patients with type 2 diabetes may be more likely to benefit from ezetimibe/statin combination therapy. However, evidence specifically addressing hard clinical endpoints and prospective trials addressing differences in response between patients with or without diabetes are still needed.