Proprotein convertase subtilisin/kexin 9 inhibitors in reducing cardiovascular outcomes: a systematic review and meta-analysis

Coronary atherosclerotic plaque modification: the present and the future

INTRODUCTION

Coronary atherosclerosis, marked by lipid deposition and inflammation, drives cardiovascular morbidity. Traditional treatments focus on lipid reduction, yet newer therapies target plaque composition, aiming to enhance stability and prevent coronary events.

AREAS COVERED

A comprehensive literature search was conducted across PubMed, Embase, and Scopus till January 2025 to identify studies on coronary plaque modification. This review highlights current and emerging therapies for coronary plaque modification. Key pharmacologic agents include Proprotein convertase subtilisin/kexin type 9 inhibitors for lipid management, colchicine for inflammation control, and Glucagon-like peptide-1 receptor agonists, and Sodium-glucose cotransporter-2 inhibitors for metabolic benefits. Clinical trials indicate these agents' roles in reducing plaque volume and vulnerability. Advances in imaging and biomarkers, such as lipoprotein(a) and inflammatory markers, enable refined monitoring of plaque changes over time.

EXPERT OPINION

Future management of atherosclerosis may involve personalized strategies, integrating AI-driven predictive tools and biomarkers to assess individual plaque characteristics and optimize therapy. Continued exploration of targeted anti-inflammatory therapies and novel biomarkers like Lp(a) could enhance outcomes, offering a more precise approach to reducing cardiovascular risk and stabilizing high-risk plaques.

Safety of proprotein convertase subtilisin/kexin 9 inhibitors: a systematic review and meta-analysis

OBJECTIVE

To determine the harms of proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors in people who need lipid-lowering therapy.

METHODS

This systematic review included randomised controlled trials that compared PCSK9 inhibitors with placebo, standard care or active lipid-lowering comparators in people who need lipid-lowering therapy with the follow-up duration of at least 24 weeks. We summarised the relative effects for potential harms from PCSK9 inhibitors using random-effect pairwise meta-analyses and assessed the certainty of evidence using GRADE (Grading of Recommendation Assessment, Development and Evaluation) for each outcome.

RESULTS

We included 32 trials with 65 861 participants (with the median follow-up duration of 40 weeks, ranging from 24 to 146 weeks). The meta-analysis showed an incidence of injection-site reaction leading to discontinuation (absolute incidence of 15 events (95% CI 11 to 20) per 1000 persons in a 5-year time frame, high certainty evidence). PCSK9 inhibitors do not increase the risk of new-onset diabetes mellitus, neurocognitive events, cataracts or gastrointestinal haemorrhage with high certainty evidence. PCSK9 inhibitors probably do not increase the risks of myalgia or muscular pain leading to discontinuation or any adverse events leading to discontinuation with moderate evidence certainty. Given very limited evidence, PCSK9 inhibitors might not increase influenza-like symptoms leading to discontinuation (risk ratio 1.5; 95% CI 0.06 to 36.58). We did not identify credible subgroup analyses results, including shorter versus longer follow-up duration of trials.

CONCLUSIONS

PCSK9 inhibitors slightly increase the risk of severe injection-site reaction but not cataracts, gastrointestinal haemorrhage, neurocognitive events, new-onset diabetes or severe myalgia or muscular pain.

Global Burden Attributable to High Low-Density Lipoprotein-Cholesterol From 1990 to 2019

BACKGROUND

High low-density lipoprotein-cholesterol (LDL-C) is a public health issue contributing to ischemic heart disease (IHD) and stroke.

METHOD

In this ecological study, we collected summary exposure values (SEVs), deaths, disability-adjusted life of years (DALYs), and Social Demographic Index (SDI) of high LDL-C from 1990 to 2019 using the query tool from the Global Burden of Disease (GBD) Collaborative Network. Outcomes include SEVs, deaths, and DALYs attributable to high LDL-C stratified by sex, age, region, SDI, countries, and territories. Estimated annual percentage changes (EAPCs) were applied to estimate annual trends of changes in these outcomes. We applied the weighted segmented regression with break-point estimation to detect the linear piecewise relationship between SDI and high LDL-C disease burden.

RESULTS

Globally, 3.00 million (95% uncertainty interval [UI], 2.35-3.76 million) people in 1990 and 4.40 million (95% UI, 3.30-5.65 million) people died from high LDL-C in 2019. The absolute annual burden from deaths and DALYs attributed to high LDL-C increased by 46% (95% UI, 35-56%) and 41% (95% UI, 31-50%) from 1990 to 2019. The age-standardized SEV, death, and DALY was decreased by 9% (95% UI, -11 to -8%), 37% (95% UI, -41-33%), and 32% (95% UI, -37 to -28%), respectively, during the study period. There was a negative association between SDI and high LDL-C-related age-standardized death and DALY rates when SDI surpassed 0.71 and 0.71, respectively.

CONCLUSION

Although the overall age-standardized burden of high LDL-C is controlled in the past 30 years, it remains increasing in moderate SDI countries, and decreasing trends are disappearing in high SDI countries. New challenges require new actions stratified by countries with different SDI levels.

PCSK9 inhibitors and ezetimibe for the reduction of cardiovascular events: a clinical practice guideline with risk-stratified recommendations

CLINICAL QUESTION

In adults with low density lipoprotein (LDL) cholesterol levels >1.8 mmol/L (>70 mg/dL) who are already taking the maximum dose of statins or are intolerant to statins, should another lipid-lowering drug be added, either a proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitor or ezetimibe, to reduce the risk of major cardiovascular events? If so, which drug is preferred? Having decided to use one, should we add the other lipid-lowering drug?

CURRENT PRACTICE

Most guidelines emphasise LDL cholesterol targets in their recommendations for prescribing PCSK9 inhibitors and/or ezetimibe in adults at high risk of experiencing a major adverse cardiovascular event. However, to achieve these goals in very high risk patients with statins alone is almost impossible, so physicians are increasingly considering other lipid-lowering drugs solely for achieving LDL cholesterol treatment goals rather than for achieving important absolute cardiovascular risk reduction. Most guidelines do not systematically assess the cardiovascular benefits of adding PCSK9 inhibitors and/or ezetimibe for all risk groups across primary and secondary prevention, nor do they report, in accordance with explicit judgments of assumed patients' values and preferences, absolute benefits and harms and potential treatment burdens.

RECOMMENDATIONS

The guideline panel provided mostly weak recommendations, which means we rely on shared decision making when applying these recommendations. For adults already using statins, the panel suggests adding a second lipid-lowering drug in people at very high and high cardiovascular risk but recommends against adding it in people at low cardiovascular risk. For adults who are intolerant to statins, the panel recommends using a lipid-lowering drug in people at very high and high cardiovascular risk but against adding it in those at low cardiovascular risk. When choosing to add another lipid-lowering drug, the panel suggests ezetimibe in preference to PCSK9 inhibitors. The panel suggests further adding a PCSK9 inhibitor to ezetimibe for adults already taking statins at very high risk and those at very high and high risk who are intolerant to statins.

HOW THIS GUIDELINE WAS CREATED

An international panel including patients, clinicians, and methodologists produced these recommendations following standards for trustworthy guidelines and using the GRADE approach. The panel identified four risk groups of patients (low, moderate, high, and very high cardiovascular risk) and primarily applied an individual patient perspective in moving from evidence to recommendations, though societal issues were a secondary consideration. The panel considered the balance of benefits and harms and burdens of starting a PCSK9 inhibitor and/or ezetimibe, making assumptions of adults' average values and preferences. Interactive evidence summaries and decision aids accompany multi-layered recommendations, developed in an online authoring and publication platform (www.magicapp.org) that also allows re-use and adaptation.

THE EVIDENCE

A linked systematic review and network meta-analysis (14 trials including 83 660 participants) of benefits found that PCSK9 inhibitors or ezetimibe probably reduce myocardial infarctions and stroke in patients with very high and high cardiovascular risk, with no impact on mortality (moderate to high certainty evidence), but not in those with moderate and low cardiovascular risk. PCSK9 inhibitors may have similar effects to ezetimibe on reducing non-fatal myocardial infarction or stroke (low certainty evidence). These relative benefits were consistent, but their absolute magnitude varied based on cardiovascular risk in individual patients (for example, for 1000 people treated with PCSK9 inhibitors in addition to statins over five years, benefits ranged from 2 fewer strokes in the lowest risk to 21 fewer in the highest risk). Two systematic reviews on harms found no important adverse events for these drugs (moderate to high certainty evidence). PCSK9 inhibitors require injections that sometimes result in injection site reactions (best estimate 15 more per 1000 in a 5 year timeframe), representing a burden and harm that may matter to patients. The MATCH-IT decision support tool allows you to interact with the evidence and your patients across the alternative options: https://magicevidence.org/match-it/220504dist-lipid-lowering-drugs/.

UNDERSTANDING THE RECOMMENDATIONS

The stratification into four cardiovascular risk groups means that, to use the recommendations, physicians need to identify their patient's risk first. We therefore suggest, specific to various geographical regions, using some reliable risk calculators that estimate patients' cardiovascular risk based on a mix of known risk factors. The largely weak recommendations concerning the addition of ezetimibe or PCSK9 inhibitors reflect what the panel considered to be a close balance between small reductions in stroke and myocardial infarctions weighed against the burdens and limited harms.Because of the anticipated large variability of patients' values and preferences, well informed choices warrant shared decision making. Interactive evidence summaries and decision aids linked to the recommendations can facilitate such shared decisions. The strong recommendations against adding another drug in people at low cardiovascular risk reflect what the panel considered to be a burden without important benefits. The strong recommendation for adding either ezetimibe or PCSK9 inhibitors in people at high and very high cardiovascular risk reflect a clear benefit.The panel recognised the key uncertainty in the evidence concerning patient values and preferences, namely that what most people consider important reductions in cardiovascular risks, weighed against burdens and harms, remains unclear. Finally, availability and costs will influence decisions when healthcare systems, clinicians, or people consider adding ezetimibe or PCSK9 inhibitors.

A Systematic Review and Meta-Analysis of Therapeutic Efficacy and Safety of Alirocumab and Evolocumab on Familial Hypercholesterolemia

Objectives

The aim of this study was to provide the first study to systematically analyze the efficacy and safety of PCSK9-mAbs in the treatment of familial hypercholesterolemia (FH).

Methods

A computer was used to search the electronic Cochrane Library, PubMed/MEDLINE, and Embase databases for clinical trials using the following search terms: "AMG 145", "evolocumab", "SAR236553/REGN727", "alirocumab", "RG7652", "LY3015014", "RN316/bococizumab", "PCSK9", and "familial hypercholesterolemia" up to November 2020. Study quality was assessed with the Cochrane Collaboration's tool, and publication bias was evaluated by a contour-enhanced funnel plot and the Harbord modification of the Egger test. After obtaining the data, a meta-analysis was performed using R software, version 4.0.3.

Results

A meta-analysis was performed on 7 clinical trials (926 total patients). The results showed that PCSK9-mAbs reduced the LDL-C level by the greatest margin, WMD -49.14%, 95% CI: -55.81 to -42.47%, on FH versus control groups. PCSK9-mAbs also significantly reduced lipoprotein (a) (Lp (a)), total cholesterol (TC), triglycerides (TG), apolipoprotein-B (Apo-B), and non-high-density lipoprotein cholesterol (non-HDL-C) levels and increased HDL-C and apolipoprotein-A1 (Apo-A1) levels of beneficial lipoproteins. Moreover, no significant difference was found between PCSK9-mAbs treatment and placebo in common adverse events, serious events, and laboratory adverse events.

Conclusion

PCSK9-mAbs significantly decreased LDL-C and other lipid levels with satisfactory safety and tolerability in FH treatment.

Macrophage Plasticity and Atherosclerosis Therapy

Atherosclerosis is a chronic disease starting with the entry of monocytes into the subendothelium and the subsequent differentiation into macrophages. Macrophages are the major immune cells in atherosclerotic plaques and are involved in the dynamic progression of atherosclerotic plaques. The biological properties of atherosclerotic plaque macrophages determine lesion size, composition, and stability. The heterogenicity and plasticity of atherosclerotic macrophages have been a hotspot in recent years. Studies demonstrated that lipids, cytokines, chemokines, and other molecules in the atherosclerotic plaque microenvironment regulate macrophage phenotype, contributing to the switch of macrophages toward a pro- or anti-atherosclerosis state. Of note, M1/M2 classification is oversimplified and only represent two extreme states of macrophages. Moreover, M2 macrophages in atherosclerosis are not always protective. Understanding the phenotypic diversity and functions of macrophages can disclose their roles in atherosclerotic plaques. Given that lipid-lowering therapy cannot completely retard the progression of atherosclerosis, macrophages with high heterogeneity and plasticity raise the hope for atherosclerosis regression. This review will focus on the macrophage phenotypic diversity, its role in the progression of the dynamic atherosclerotic plaque, and finally discuss the possibility of treating atherosclerosis by targeting macrophage microenvironment.

Different Lipid Parameters in Predicting Clinical Outcomes in Chinese Statin-Naïve Patients After Coronary Stent Implantation

Background: Low-density lipoprotein cholesterol (LDL-C) is a critical surrogate outcome for cardiovascular disease (CVD). Recent observational studies identified different predictive lipid parameters, but these have not been fully validated in the Chinese population. This study aimed to compare the predictive value of lipid parameters for cardiovascular outcomes in Chinese statin-naïve patients who underwent percutaneous coronary intervention (PCI). Methods: We retrospectively recruited statin-naïve patients who underwent PCI for stable angina and acute coronary syndrome at Sichuan Provincial People's Hospital between 1 January 2016 and 31 December 2017. A follow-up was conducted via outpatient visits or telephone. We divided patients into three groups based on lipid parameter tertiles. We calculated the hazard ratios (HRs) of the highest and lowest tertiles for major adverse cardiovascular events (MACEs) using multivariate Cox proportional hazards regression. We compared the association strength of lipid parameters with MACEs using the HR of non-LDL-C lipid parameters relative to LDL-C. Results: Among 445 included patients, the highest LDL-C, LDL-C/high-density lipoprotein cholesterol (HDL-C), atherosclerosis index, and non-HDL-C level tertiles were associated with an average increase of 165% (HR 2.65, confidence interval [CI] 1.26 to 5.61; P = 0.01), 324% (HR 4.24, CI 1.89 to 9.52; P < 0.001), 152% (HR 2.52, CI 1.22 to 5.22; P = 0.01), and 125% (HR 2.25, CI 1.09 to 4.64; P = 0.01) in the hazard of composite CVD, respectively. Lipoprotein (a) levels did not show a significant association with the endpoints. Except for LDL-C/HDL-C, different lipid parameter HR ratios were <1.0; none were statistically significant. Conclusion: Compared with non-LDL-C lipid parameters, LDL-C acts better predictive value for cardiovascular outcomes in general Chinese statin-naïve post-PCI patients.

Management of Dyslipidemia for Cardiovascular Disease Risk Reduction: Synopsis of the 2020 Updated U.S. Department of Veterans Affairs and U.S. Department of Defense Clinical Practice Guideline

DESCRIPTION

In June 2020, the U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DoD) released a joint update of their clinical practice guideline for managing dyslipidemia to reduce cardiovascular disease risk in adults. This synopsis describes the major recommendations.

METHODS

On 6 August to 9 August 2019, the VA/DoD Evidence-Based Practice Work Group (EBPWG) convened a joint VA/DoD guideline development effort that included clinical stakeholders and conformed to the Institute of Medicine's tenets for trustworthy clinical practice guidelines. The guideline panel developed key questions, systematically searched and evaluated the literature (English-language publications from 1 December 2013 to 16 May 2019), and developed 27 recommendations and a simple 1-page algorithm. The recommendations were graded by using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system.

RECOMMENDATIONS

This synopsis summarizes key features of the guideline in 7 crucial areas: targeting of statin dose (not low-density lipoprotein cholesterol goals), additional tests for risk prediction, primary and secondary prevention, laboratory testing, physical activity, and nutrition.

The impact of a run-in period on treatment effects in cardiovascular prevention randomised control trials: A protocol for a comprehensive review and meta-analysis

Background: A run-in period is often employed in randomised controlled trials to increase adherence to the intervention and reduce participant loss to follow-up in the trial population. However, it is uncertain whether use of a run-in period affects the magnitude of treatment effect. Methods: We will conduct a sensitive search for systematic reviews of cardiovascular preventative trials and a complete meta-analysis of treatment effects comparing cardiovascular prevention trials using a run-in period (“run-in trials”) with matched cardiovascular prevention trials that did not use a run-in period (“non-run-in trials”). We describe a comprehensive matching process which will match run-in trials with non-run-in trials by patient populations, interventions, and outcomes. For each pair of run-in trial and matched non-run-in trial(s), we will estimate the ratio of relative risks and 95% confidence interval. We will evaluate differences in treatment effect between run-in and non-run-in trials and our and our priamry outcome will be the ratio of relative risks for matched run-in and non-run-in trials for their reported cardiovascular composite outcome. Our secondary outcomes are comparisons of mortality, loss to follow up, frequency of adverse events and methodological quality of trials. Conclusions: This study will answer a key question about what influence a run-in period has on the magnitude of treatment effects in randomised controlled trials for cardiovascular prevention therapies.

Proprotein convertase subtilisin/kexin type 9 inhibition in cardiovascular disease: current status and future perspectives

Proprotein convertase subtilisin/kexin type 9 (PCSK9) targets the degradation of low-density lipoprotein (LDL) receptors; it has been proved that its inhibition improves cardiovascular outcomes in patients with established atherosclerotic cardiovascular disease (ASCVD). Herein, we review the current status of PCSK9 inhibitors in clinical practice and the future scope of PCSK9 inhibition. The results of two recent large clinical trials reveal that two PCSK9 monoclonal antibodies evolocumab and alirocumab reduce the risk of a cardiovascular event on top of background statin therapy in patients with stable ASCVD and those with recent acute coronary syndrome, respectively. However, there are several ongoing concerns regarding the efficacy in reducing mortality, cost-effectiveness, and long-term safety of extremely low LDL cholesterol levels with PCSK9 inhibition. The results of ongoing cardiovascular outcomes trials with PCSK9 monoclonal antibodies for primary prevention and with small interfering RNA to PCSK9 for secondary prevention may help to shape the use of this new therapeutic class.

Efficacy and Safety of PCSK9 Monoclonal Antibodies in Patients at High Cardiovascular Risk: An Updated Systematic Review and Meta-Analysis of 32 Randomized Controlled Trials

INTRODUCTION

Proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies are powerful lipid-lowering drugs which have been shown to improve clinical endpoints in patients with hypercholesterolemia. However, it is not clear how effective PCSK9 monoclonal antibodies are for patients at high cardiovascular risk. Also, whether the effectiveness of PCSK9 monoclonal antibodies varies between different drug types, dosages, race, and indications for PCSK9 monoclonal antibodies remains unclear. Therefore, we used recently published studies to systematically evaluate the efficacy and safety of PCSK9 monoclonal antibodies by analyzing the lipid profiles, adverse events, and clinical endpoints in patients at high cardiovascular risk.

METHODS

Randomized controlled trials (RCTs) comparing PCSK9 monoclonal antibodies with placebos or active drugs in patients at high cardiovascular risk were retrieved from electronic databases from their inception until November 2019. Efficacy and safety outcomes included low-density lipoprotein cholesterol (LDL-C) and other lipid profiles, treatment-emergent adverse events (TEAEs) and adverse events of interests, and clinical endpoints. Subgroup analyses based on drug types, dosing, and race were conducted. Statistical analysis was performed using STATA 15.1 and RevMan 5.0.

RESULTS

Thirty-two RCTs were included in the systematic review, and 25 of them (57,090 individuals) were included in the meta-analysis. PCSK9 monoclonal antibodies significantly improved LDL-C and other lipid profiles (P < 0.05), and no racial differences were found. A recommended dose of 140 mg of evolocumab every 2 weeks was likely to produce a relatively stronger effect than 150 mg of alirocumab every 2 weeks in terms of the absolute change (weighted mean differences (WMD) - 0.36; 95% confidence interval (CI) - 0.71 to - 0.01; P = 0.041) and percent change (WMD - 19.53; 95% CI - 32.02 to - 7.04; P = 0.002) in LDL-C levels. Overall, PCSK9 monoclonal antibodies were safe, except for the significantly increased risk of injection site reactions (relative risks (RR) 1.54; 95% CI 1.38-1.71; P < 0.001). Both alirocumab (RR 0.89; 95% CI 0.83-0.95; P < 0.001) and evolocumab (RR 0.86; 95% CI 0.80-0.92; P < 0.001) were associated with a lower risk of major cardiovascular events (MACEs), especially in secondary preventive patients (alirocumab group: RR 0.88; 95% CI 0.82-0.95; P < 0.001; evolocumab group: RR 0.86; 95% CI 0.80-0.92; P < 0.001). The reduction in MACEs was observed in White but not in Asian subjects. No significant reduction of all-cause mortality was found (RR 0.88; 95% CI 0.72-1.07; P = 0.182).

CONCLUSION

Both alirocumab and evolocumab are well tolerated and can greatly improve lipid profiles for patients at high cardiovascular risk. Both PCSK9 monoclonal antibodies significantly reduce the risk of nonfatal MACEs in patients with previous cardiovascular events, but the effect on all-cause mortality remains uncertain.

Cost-Effectiveness Analysis of Ezetimibe as the Add-on Treatment to Moderate-Dose Rosuvastatin versus High-Dose Rosuvastatin in the Secondary Prevention of Cardiovascular Diseases in China: A Markov Model Analysis

BACKGROUND

For patients with inadequate control of cholesterol using moderate-dose statins in the secondary prevention of cardiovascular diseases (CVD), either doubling the dose of statins or adding ezetimibe should be considered. The cost-effectiveness of them is unknown in the Chinese context. The aim of this study is to compare the cost and effectiveness of the two regimens, and estimate the incremental cost-effectiveness ratio (ICER).

METHODS

A Markov model of five health statuses were used to estimate long-term costs and quality-adjusted life-years (QALYs) of the two treatment regimens from the healthcare perspective. The effectiveness data used to calculate the transition probability was based on a previously published randomized trial. The utility data was gathered from literature and the costs were gathered from the electronic medical record system of West China Hospital in Chinese Yuan (CNY) in 2017 price. One-way sensitivity analysis and probabilistic sensitivity analysis were conducted.

RESULTS

The ICER for ezetimibe plus moderate-dose rosuvastatin was 47,102.99 CNY per QALY for 20 years simulation, which did not reach the threshold of per capita gross domestic product (GDP) of 59,660 CNY per QALY in 2017 in China. Non-CVD-related mortality and CVD-related mortality contributed most to the ICER.

CONCLUSION

Adding ezetimibe to the moderate-dose statin in secondary prevention for CVD is cost-effective, compared with the high-dose statin in the Chinese context whose low-density lipoprotein cholesterol (LDL-c) was not inadequately controlled by moderate-dose statin alone.

Macrophages in Atherosclerosis Regression

Macrophages play a central role in the development of atherosclerotic cardiovascular disease (ASCVD), which encompasses coronary artery disease, peripheral artery disease, cerebrovascular disease, and aortic atherosclerosis. In each vascular bed, macrophages contribute to the maintenance of the local inflammatory response, propagate plaque development, and promote thrombosis. These central roles, coupled with their plasticity, makes macrophages attractive therapeutic targets in stemming the development of and stabilizing existing atherosclerosis. In the context of ASCVD, classically activated M1 macrophages initiate and sustain inflammation, and alternatively activated M2 macrophages resolve inflammation. However, this classification is now considered an oversimplification, and a greater understanding of plaque macrophage physiology in ASCVD is required to aid in the development of therapeutics to promote ASCVD regression. Reviewed herein are the macrophage phenotypes and molecular regulators characteristic of ASCVD regression, and the current murine models of ASCVD regression.