Application Value of PCSK9 Inhibitor in Cardiovascular High Risk Patients: A Meta-Analysis.

Background: Proprotein convertase subtilisin / Kexin type 9 (PCSK9) inhibitors are efficacious lipid-lowering agents. This drug is related to improving the prognosis of patients with cardiovascular disease (CVD). The purpose of this meta-analysis was to systematically analyze the safety and efficacy of PCSK9 inhibitors in all published randomized controlled trials (RCTs). Methods: As of October 25, 2021, we searched PubMed, EMBASE, MEDLINE, Cochrane Library and web of science. Results: From 684 articles, we included 11 trials for meta-analysis, including 52511 participants (26938 in the PCSK9 inhibitor group and 25573 in the control group). In terms of effectiveness, PCSK9 inhibitors reduced the risk of major adverse cardiovascular events(MACE) (OR=0.89, 95% Cl: 0.83-0.95, P=0.0009), but did not significantly reduce the risk of cardiovascular death (OR=0.95, 95% Cl: 0.84-1.07, P=0.38) or all-cause death (OR=0.93, 95% Cl: 0.85-1.03, P=0.18); In terms of safety, PCSK9 did not increase the risk of treatment-emergent adverse events (TEAE)(OR=0.98, 95% Cl: 0.94-1.02, P=0.28). Conclusion: PCSK9 inhibitors can significantly reduce the risk of MACE in patients with high cardiovascular risk, which is well tolerated, but the impact on the risk of death is unclear.

New Loss-of-Function Mutations in PCSK9 Reduce Plasma LDL Cholesterol.

BACKGROUND: Lower plasma levels of LDL (low-density lipoprotein) cholesterol (LDL-C) can reduce the risk of atherosclerotic cardiovascular disease. The loss-of-function mutations in PCSK9 (proprotein convertase subtilisin/kexin type 9) have been known to associate with low LDL-C in many human populations. PCSK9 genetic variants in Chinese Uyghurs who are at high risk of atherosclerotic cardiovascular disease due to their dietary habits have not been reported. METHODS: The study involved the whole-exome and target sequencing of college students from Uyghur and other ethnic groups in Xinjiang, China, for the association of PCSK9 loss-of-function mutations with low plasma levels of LDL-C. The mechanisms by which the identified mutations affect the function of PCSK9 were investigated in cultured cells using biochemical and cell assays. The causal effects of the identified PCSK9 mutations on LDL-C levels were verified in mice injected with adeno-associated virus expressing different forms of PCSK9 and fed a high-cholesterol diet. RESULTS: We identified 2 PCSK9 mutations-E144K and C378W-in Chinese Uyghurs with low plasma levels of LDL-C. The E144K and C378W mutations impaired the maturation and secretion of the PCSK9 protein, respectively. Adeno-associated virus-mediated expression of E144K and C378W mutants in Pcsk9 KO (knockout) mice fed a high-cholesterol diet also hampered PCSK9 secretion into the serum, resulting in elevated levels of LDL receptor in the liver and reduced levels of LDL-C in the serum. CONCLUSIONS: Our study shows that E144K and C378W are PCSK9 loss-of-function mutations causing low LDL-C levels in mice and probably in humans as well.

European Physician Survey Characterizing the Clinical Pathway and Treatment Patterns of Patients Post-Myocardial Infarction.

INTRODUCTION: The 2019 European Society of Cardiology and European Atherosclerosis Society (2019 ESC/EAS) guidelines stress the importance of managing low-density lipoprotein cholesterol (LDL-C) after myocardial infarction (MI) to reduce the risk of cardiovascular events. Information on guideline implementation is limited. The aim of this survey was to describe current clinical practice regarding LDL-C management in the first year post-MI across Europe, improving understanding of the role of ESC/EAS guidelines on clinical practice. METHODS: A qualitative web-based cross-sectional physician survey about the patient pathway and LDL-C management post-MI was conducted in 360 physicians from France, Italy, Germany, The Netherlands, Spain, and the UK (n = 60/country) between December 2019 and June 2020. Secondary and primary care physicians (SCPs/PCPs) described their experiences treating patients post-MI over the preceding 2 months. RESULTS: Physicians reported that on average 90.7% of patients not prescribed lipid-lowering therapy (LLT) before an MI initiated LLT as inpatients; for patients already taking LLT, treatment was intensified for 64.7% of inpatients post-MI. SCPs reported prescribing higher-intensity statins and/or ezetimibe for between 72.3% (Italy) and 88.6% (UK) of patients post-MI. More than 80.0% of SCPs and 51.2% of PCPs stated that they would initiate a change in LLT immediately if patients did not achieve their LDL-C treatment goal by 12 weeks post-MI; 82.0% of SCPs and 55.1% of PCPs reported referring to 2019 ESC/EAS guidelines for management of patients post-MI. Barriers to initiating PCSK9 inhibitors (PCSK9is) included prior prescription of a maximally tolerated dose of statin (49.4%) and/or ezetimibe (38.9%), requirement to reach threshold LDL-C levels (44.9%), and pre-authorization requirements (30.4%). CONCLUSION: Differences in clinical practice post-MI were reported across the countries surveyed, including divergence between 2019 ESC/EAS and local guidelines. Increased use of innovative medicines to achieve LDL-C goals should reduce risk of subsequent cardiovascular events in very high-risk patients post-MI.

Effect of empagliflozin on plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) in patients with type 2 diabetes.

AIM: Cardiovascular benefits of sodium-glucose cotrasporter-2 (SGLT2) inhibitors occur despite a modest increase in low-density lipoprotein cholesterol (LDL-c). We tested whether the effects of chronic SGLT2 inhibition on lipid profile composition are mediated by elevation in plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) levels inhibiting LDL clearance. METHODS: 78 patients with type 2 diabetes (T2D) received empagliflozin 25 mg/d in an open-label design. At enrollment and after 4-week therapy, fasting blood samples were collected for the measurement of plasma PCSK9, glucose, total and fractional cholesterol, and triglycerides. RESULTS: Plasma PCSK9 was not significantly affected by empagliflozin (-10.7 [-24.1, 2.7] ng/mL). The treatment induced a mild increase in high-density lipoprotein cholesterol (+1.7 [0.5, 3.0] mg/dL), without significant LDL-c alterations (+1.0 [-4.1, 6.0] mg/dl). Changes in LDL-c were associated with changes in fasting glucose levels (ß = 0.320, p = 0.017), but not with plasma PCSK9 (ß = 0.010, p = 0.800), after adjustment for age, sex, baseline LDL-c, and body weight change. CONCLUSION: In patients with T2D, chronic SGLT2 inhibition with empagliflozin has no potentially harmful effects on circulating PCSK9 levels. This finding does not support a pathogenetic role of plasma PCSK9 in the mild plasma lipid alterations observed during SGLT2i treatment.

Rationale and design of two trials assessing the efficacy, safety, and tolerability of inclisiran in adolescents with homozygous and heterozygous familial hypercholesterolaemia.

BACKGROUND: Inclisiran is a small interfering RNA molecule that reduces low-density lipoprotein cholesterol (LDL-C) by inhibition of proprotein convertase subtilisin/kexin type 9. This subcutaneous, twice-yearly administered agent has been shown to effectively and safely lower LDL-C in adult patients with established atherosclerotic cardiovascular disease, adults at high risk for atherosclerotic cardiovascular disease, as well as in adults with heterozygous familial hypercholesterolaemia. With the current, limited treatment options available to reach treatment goals in children with severe heterozygous familial hypercholesterolaemia, homozygous familial hypercholesterolaemia, or statin intolerance, inclisiran could be a valuable new therapeutic option. OBJECTIVES: The objective of these ongoing studies is to investigate the efficacy, safety, and tolerability of inclisiran in adolescents diagnosed with homozygous familial hypercholesterolaemia (ORION-13) or heterozygous familial hypercholesterolaemia (ORION-16). STUDY DESIGN: ORION-13 and ORION-16 are both two-part (1-year double-blind inclisiran vs. placebo/1 year open-label inclisiran) multicentre trials including adolescents aged 12 to <18 years diagnosed with familial hypercholesterolaemia. ORION-13 will include ∼12 participants diagnosed with homozygous familial hypercholesterolaemia and ORION-16 will include ∼150 participants diagnosed with heterozygous familial hypercholesteroleamia. The primary endpoint is the percentage change in LDL-C from baseline to Day 330. Secondary efficacy and safety endpoints include changes in other lipid parameters and treatment-emergent adverse events as well as laboratory parameters and vital signs. Exploratory endpoints include individual responsiveness of the participants and change in LDL-C according to the type of underlying causal mutation. CLINICAL TRIAL REGISTRATION: https://www.clinicaltrials.gov/. Unique identifier: NCT04659863 (ORION-13) and NCT04652726 (ORION-16).

A Retrospective Chart Review Evaluating Efficacy, Tolerability, and Cost of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors (PCSK9i) in Older Adults.

INTRODUCTION: Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) are proven to have profound lowering of low-density lipoprotein cholesterol (LDL-C) in patients with clinical atherosclerotic cardiovascular disease or familial hypercholesterolemia. AIM: The primary purpose of this study was to evaluate PCSK9i utilization in older adults, with a focus on efficacy outcomes within 6 months of initiation. Secondary outcomes included tolerability, out-of-pocket expenses (OPE), and barriers to initiation of therapy. METHODS: We conducted a retrospective chart review of patients ≥ 65 years prescribed PCSK9i therapy by a pharmacist-run lipid clinic within a cardiology practice. RESULTS: A total of 136 older adults were prescribed PCSK9i therapy for a Food and Drug Administration-approved indication between September 2015 and March 2019 with 98 patients included in the analyses. In terms of efficacy, 51 patients who took ≥ 3 doses of PCSK9i with baseline and follow-up lipid panels were assessed. On average, LDL-C reduced by 60% (169-67 mg/dL, p < 0.001). For tolerability, 15 patients reported treatment-emergent side effects, resulting in 10 therapy discontinuations. For the cost analysis, 72 patients reported anticipated OPE for 1 month of therapy. Ultimately 17 patients were approved for manufacturer patient assistance with $0 OPE and 31 patients utilized insurance coverage to obtain therapy reporting a median OPE of $9 United States Dollars ($0-$450). The main barrier to initiation was high OPE. CONCLUSIONS: PCSK9i are effective at lowering LDL-C in older adults. Tolerability was high among patients without a history of statin intolerance. PCSK9i remain high-cost medications to both insurance companies and patients in terms of cost-sharing responsibilities.

Stroke Prevention With the PCSK9 (Proprotein Convertase Subtilisin-Kexin Type 9) Inhibitor Evolocumab Added to Statin in High-Risk Patients With Stable Atherosclerosis.

Background and Purpose- The PCSK9 (proprotein convertase subtilisin-kexin type 9) monoclonal antibody evolocumab lowered LDL (low-density lipoprotein) cholesterol by 59% to 0.8 (0.5-1.2) mmol/L and significantly reduced major vascular events in the FOURIER trial (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk). Herein, we report the results of a prespecified analysis of cerebrovascular events in the overall trial population and in patients stratified by prior stroke. Methods- FOURIER was a randomized, double-blind trial comparing evolocumab versus placebo in patients with established atherosclerosis, additional risk factors, and LDL cholesterol levels ≥1.8 (or non-HDL [high-density lipoprotein] ≥2.6 mmol/L) on statin therapy. The median follow-up was 2.2 years. We analyzed the efficacy of evolocumab to reduce overall stroke and stroke subtypes, as well as the primary cardiovascular composite end point by subgroups according to a history of stroke. Results- Among the 27 564 patients, 469 (1.7%) experienced a total of 503 strokes of which 421 (84%) were ischemic. Prior ischemic stroke, diabetes mellitus, elevated CRP (C-reactive protein), history of heart failure, older age, nonwhite race, peripheral arterial disease, and renal insufficiency were independent predictors of stroke. Evolocumab significantly reduced all stroke (1.5% versus 1.9%; hazard ratio, 0.79 [95% CI, 0.66-0.95]; P=0.01) and ischemic stroke (1.2% versus 1.6%; hazard ratio, 0.75 [95% CI, 0.62-0.92]; P=0.005), with no difference in hemorrhagic stroke (0.21% versus 0.18%; hazard ratio, 1.16 [95% CI, 0.68-1.98]; P=0.59). These findings were consistent across subgroups, including among the 5337 patients (19%) with prior ischemic stroke in whom the hazard ratios (95% CIs) were 0.85 (0.72-1.00) for the cardiovascular composite, 0.90 (0.68-1.19) for all stroke, and 0.92 (0.68-1.25) for ischemic stroke (P interactions, 0.91, 0.22, and 0.09, respectively, compared with patients without a prior ischemic stroke). Conclusions- Inhibition of PCSK9 with evolocumab added to statin in patients with established atherosclerosis reduced ischemic stroke and cardiovascular events in the total population and in key subgroups, including those with prior ischemic stroke. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT01764633.

PCSK9 Inhibitors: Clinical Relevance, Molecular Mechanisms, and Safety in Clinical Practice / Inibidores de PCSK9: Importância Clínica, Mecanismos Moleculares, e Segurança na Prática Clínica

Abstract Coronary artery disease (CAD) is one of the leading causes of mortality. High circulating levels of low-density lipoprotein (LDL) in the blood are associated with cardiovascular mortality, whether through an etiological role or through its association with the progression of CAD per se. Randomized clinical trials have shown that, when LDL levels are reduced, cardiovascular risk is also reduced, which reinforces this association. The first major trial involving a hypolipidemic agent of the statin family, the Scandinavian Simvastatin Survival Study (4S), was published in 1994 and found a significant reduction in mortality in patients at high cardiovascular risk. However, even in subsequent studies with different statins, a residual risk persisted, and this seems not to have changed over time; it is speculated that this risk may be due to statin intolerance. In this scenario, the potential exists for novel hypolipidemic agents to drive a true revolution in the therapy of dyslipidemia. The recent discovery of PCSK9 inhibitors (PCSK9i), a class of hypolipidemic monoclonal antibodies, is extremely promising. PCSK9 inhibition is capable of promoting a mean LDL reduction of up to 60%, with potential for very significant clinical repercussions, as every 38 mg/dL reduction in LDL appears to be associated with a 22% reduction in cardiovascular risk. This review addresses a brief history of PCSK9i, major trials of these drugs, cardiovascular outcomes, and aspects related to their efficacy and safety. Finally, the molecular mechanisms and possible pleiotropic effects of PCSK9i are also discussed.

Resumo A doença arterial coronariana (DAC) é uma das principais causas de mortalidade. Níveis circulantes elevados de lipoproteína de baixa densidade (LDL) no sangue estão associados com mortalidade cardiovascular, seja por um papel etiológico ou por sua associação com a progressão da DAC em si. Estudos clínicos randomizados mostram que, quando os níveis de LDL são reduzidos, o risco cardiovascular também é reduzido, o que reforça tal associação. O primeiro ensaio importante envolvendo um agente hipolipemiante da família da estatina, o estudo Scandinavian Simvastatin Survival Study (4S), foi publicado em 1994 e encontrou uma redução significativa na mortalidade de pacientes com risco cardiovascular elevado. Contudo, mesmo em estudos subsequentes com diferentes estatinas, observou-se um risco residual persistente, o qual aparentemente não mudou ao longo dos anos. Especula-se que esse risco se deve à intolerância às estatinas. Nesse cenário, existe um potencial para novos agentes hipolipemiantes que levem a uma verdadeira revolução no tratamento das dislipidemias. A descoberta recente dos inibidores de PCSK9 (PCSK9i), uma classe de anticorpos monoclonais, é extremamente promissora. A inibição da PCSK9 é capaz de promover uma redução média nos níveis de LDL de até 60%, com potencial para repercussões clínicas muito significativas, já que para cada redução de 38 mg/dL, parece haver uma redução de 22% no risco cardiovascular. Esta revisão aborda uma breve história dos PCSK9i, os principais ensaios envolvendo esses medicamentos, desfechos cardiovasculares, e aspectos relacionados a sua eficácia e segurança. Finalmente, os mecanismos moleculares e possíveis efeitos pleiotrópicos dos PCSK9i são também discutidos.

Serum Levels of PCSK9 Are Associated with Coronary Angiographic Severity in Patients with Acute Coronary Syndrome.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a circulating protein that promotes degradation of the low density lipoprotein receptor. PCSK9 has emerged as a target for lipid-lowering therapy, but the predictive value of the serum level of PCSK9 for the severity of coronary disease is largely unknown. METHODS: From December 2009 to July 2012, 121 individuals who underwent coronary angiography (CAG) because of clinically suspected acute coronary syndrome were enrolled in this study. Serum levels of PCSK9 and metabolic parameters were measured. SYNTAX (SYNergy between percutaneous coronary intervention with [paclitaxel-eluting] TAXUS stent and cardiac surgery) and GRACE (Global Registry of Acute Coronary Events) scores were calculated. RESULTS: Individuals with CAG lesions (n=100) had significantly higher levels of PCSK9 than those without lesions (n=21). The study population was stratified into three groups according to serum levels of PCSK9. The odds radio for occurrence of one or more CAG lesions was significantly higher in the group with the highest level of PCSK9 (odds ratio, 7.468; P=0.011) than in the group with the lowest level of PCSK9. Serum PCSK9 was positively associated with the number of involved coronary arteries. Multivariable linear regression indicated that levels of PCSK9 were positively correlated with GRACE risk scores and SYNTAX scores. CONCLUSION: Serum PCSK9 concentrations are higher in patients with coronary artery lesions, and are associated with SYNTAX and GRACE scores, suggesting that PCSK9 is a potential biomarker of the severity of coronary artery disease.

Serum Levels of PCSK9 Are Associated with Coronary Angiographic Severity in Patients with Acute Coronary Syndrome.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a circulating protein that promotes degradation of the low density lipoprotein receptor. PCSK9 has emerged as a target for lipid-lowering therapy, but the predictive value of the serum level of PCSK9 for the severity of coronary disease is largely unknown. METHODS: From December 2009 to July 2012, 121 individuals who underwent coronary angiography (CAG) because of clinically suspected acute coronary syndrome were enrolled in this study. Serum levels of PCSK9 and metabolic parameters were measured. SYNTAX (SYNergy between percutaneous coronary intervention with [paclitaxel-eluting] TAXUS stent and cardiac surgery) and GRACE (Global Registry of Acute Coronary Events) scores were calculated. RESULTS: Individuals with CAG lesions (n=100) had significantly higher levels of PCSK9 than those without lesions (n=21). The study population was stratified into three groups according to serum levels of PCSK9. The odds radio for occurrence of one or more CAG lesions was significantly higher in the group with the highest level of PCSK9 (odds ratio, 7.468; P=0.011) than in the group with the lowest level of PCSK9. Serum PCSK9 was positively associated with the number of involved coronary arteries. Multivariable linear regression indicated that levels of PCSK9 were positively correlated with GRACE risk scores and SYNTAX scores. CONCLUSION: Serum PCSK9 concentrations are higher in patients with coronary artery lesions, and are associated with SYNTAX and GRACE scores, suggesting that PCSK9 is a potential biomarker of the severity of coronary artery disease.

Serum Levels of PCSK9 Are Associated with Coronary Angiographic Severity in Patients with Acute Coronary Syndrome

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a circulating protein that promotes degradation of the low density lipoprotein receptor. PCSK9 has emerged as a target for lipid-lowering therapy, but the predictive value of the serum level of PCSK9 for the severity of coronary disease is largely unknown. METHODS: From December 2009 to July 2012, 121 individuals who underwent coronary angiography (CAG) because of clinically suspected acute coronary syndrome were enrolled in this study. Serum levels of PCSK9 and metabolic parameters were measured. SYNTAX (SYNergy between percutaneous coronary intervention with [paclitaxel-eluting] TAXUS stent and cardiac surgery) and GRACE (Global Registry of Acute Coronary Events) scores were calculated. RESULTS: Individuals with CAG lesions (n=100) had significantly higher levels of PCSK9 than those without lesions (n=21). The study population was stratified into three groups according to serum levels of PCSK9. The odds radio for occurrence of one or more CAG lesions was significantly higher in the group with the highest level of PCSK9 (odds ratio, 7.468; P=0.011) than in the group with the lowest level of PCSK9. Serum PCSK9 was positively associated with the number of involved coronary arteries. Multivariable linear regression indicated that levels of PCSK9 were positively correlated with GRACE risk scores and SYNTAX scores. CONCLUSION: Serum PCSK9 concentrations are higher in patients with coronary artery lesions, and are associated with SYNTAX and GRACE scores, suggesting that PCSK9 is a potential biomarker of the severity of coronary artery disease.

Pooled Safety Analysis of Evolocumab in Over 6000 Patients From Double-Blind and Open-Label Extension Studies.

BACKGROUND: Evolocumab, a fully human monoclonal antibody to PCSK9 (proprotein convertase subtilisin/kexin type 9), markedly reduces low-density lipoprotein cholesterol across diverse patient populations. The objective of this study was to assess the safety and tolerability of evolocumab in a pooled safety analysis from phase 2 or 3 randomized and placebo or comparator-controlled trials (integrated parent trials) and the first year of open-label extension (OLE) trials that included a standard-of-care control group. METHODS: This analysis included adverse event (AE) data from 6026 patients in 12 phase 2 and 3 parent trials, with a median exposure of 2.8 months, and, of those patients, from 4465 patients who continued with a median follow-up of 11.1 months in 2 OLE trials. AEs were analyzed separately for the parent and OLE trials. Overall AE rates, serious AEs, laboratory assessments, and AEs of interest were evaluated. RESULTS: Overall AE rates were similar between evolocumab and control in the parent trials (51.1% versus 49.6%) and in year 1 of OLE trials (70.0% versus 66.0%), as were those for serious AEs. Elevations of serum transaminases, bilirubin, and creatine kinase were infrequent and similar between groups. Muscle-related AEs were similar between evolocumab and control. Neurocognitive AEs were infrequent and balanced during the double-blind parent studies (5 events [0.1%], evolocumab groups versus 6 events [0.3%], control groups). In the OLE trials, 27 patients (0.9%) in the evolocumab groups and 5 patients (0.3%) in the control groups reported neurocognitive AEs. No neutralizing antievolocumab antibodies were detected. CONCLUSIONS: Overall, this integrated safety analysis of 6026 patients pooled across phase 2/3 trials and 4465 patients who continued in OLE trials for 1 year supports a favorable benefit-risk profile for evolocumab.