Cardiovascular Efficacy and Safety of Bococizumab in High-Risk Patients

Current pharmacotherapy for the treatment of dyslipidemia associated with HIV infection

Introduction: Cardiovascular disease is an important cause of morbidity and mortality in persons with human immunodeficiency virus (PWH). The risk of atherosclerotic cardiovascular disease (ASCVD) is higher in PWH compared to uninfected persons. Dyslipidemia is a critical link in the pathogenesis of ASCVD in PWH. Chronic inflammation associated with HIV infection may drive both dyslipidemia and ASCVD. Areas covered: The authors review the evidence for using lipid-lowering therapy in PWH and includes an overview of the utility and complexity of using statins in PWH, in particular, drug interactions, safety, and efficacy. In addition, data covering alternate therapies like omega-3 fatty acids, fibrates, niacin, ezetimibe, and PCSK-9 inhibitors are reviewed. Expert opinion: Dyslipidemia is a common problem in PWH. The risk of ASCVD is higher in PWH. Lipid-lowering therapy reduces the risk of ASCVD, but clinical endpoint trials are lacking in PWH. Statin therapy is the mainstay of primary prevention for ASCVD. The timing of when to initiate primary prevention with statins in PWH is unclear. Beyond statins, there are limited data that other lipid-lowering agents have utility in PWH. Ongoing trials like the REPRIEVE trial will inform the community about the optimal approach to lipid-lowering therapy in PWH.

NLRP3 Inflammasome and the IL-1 Pathway in Atherosclerosis

Inflammation is an important driver of atherosclerosis, the underlying pathology of cardiovascular diseases. Therefore, therapeutic targeting of inflammatory pathways is suggested to improve cardiovascular outcomes in patients with cardiovascular diseases. This concept was recently proven by CANTOS (Canakinumab Anti-Inflammatory Thrombosis Outcomes Study), which demonstrated the therapeutic potential of the monoclonal IL (interleukin)-1β-neutralizing antibody canakinumab. IL-1β and other IL-1 family cytokines are important vascular and systemic inflammatory mediators, which contribute to atherogenesis. The NLRP3 (NOD [nucleotide oligomerization domain]-, LRR [leucine-rich repeat]-, and PYD [pyrin domain]-containing protein 3) inflammasome, an innate immune signaling complex, is the key mediator of IL-1 family cytokine production in atherosclerosis. NLRP3 is activated by various endogenous danger signals abundantly present in atherosclerotic lesions, such as oxidized low-density lipoprotein and cholesterol crystals. Consequently, NLRP3 inflammasome activation contributes to the vascular inflammatory response driving atherosclerosis development and progression. Here, we review the mechanisms of NLRP3 inflammasome activation and proinflammatory IL-1 family cytokine production in the context of atherosclerosis and discuss treatment possibilities in light of the positive outcomes of the CANTOS trial.

Discontinued Drugs for the Treatment of Cardiovascular Disease from 2016 to 2018

Cardiovascular drug research and development (R&D) has been in active state and continuously attracts attention from the pharmaceutical industry. However, only one individual drug can eventually reach the market from about the 10,000 compounds tested. It would be useful to learn from these failures when developing better strategies for the future. Discontinued drugs were identified from a search performed by Thomson Reuters Integrity. Additional information was sought through PubMed, ClinicalTrials.gov, and pharmaceutical companies search. Twelve compounds discontinued for cardiovascular disease treatment after reaching Phase I-III clinical trials from 2016 to 2018 are detailed in this manuscript, and the reasons for these failures are reported. Of these, six candidates (MDCO-216, TRV027, ubenimex, sodium nitrite, losmapimod, and bococizumab) were dropped for lack of clinical efficacy, the other six for strategic or unspecified reasons. In total, three candidates were discontinued in Phase I trials, six in Phase II, and three in Phase III. It was reported that the success rate of drug R&D utilizing selection biomarkers is higher. Four candidate developments (OPC-108459, ONO-4232, GSK-2798745, and TAK-536TCH) were run without biomarkers, which could be used as surrogate endpoints in the 12 cardiovascular drugs discontinued from 2016 to 2018. This review will be useful for those involved in the field of drug discovery and development, and for those interested in the treatment of cardiovascular disease.

Medical Therapy for Long-Term Prevention of Atherothrombosis Following an Acute Coronary Syndrome: JACC State-of-the-Art Review

Following an acute coronary syndrome (ACS), heightened predisposition to atherothrombotic events may persist for years. Advances in understanding the pathobiology that underlies this elevated risk furnish a mechanistic basis for devising long-term secondary prevention strategies. Recent progress in ACS pathophysiology has challenged the focus on single "vulnerable plaques" and shifted toward a more holistic consideration of the "vulnerable patient," thus highlighting the primacy of medical therapy in secondary prevention. Despite current guideline-directed medical therapy, a consistent proportion of post-ACS patients experience recurrent atherothrombosis due to unaddressed "residual risk": contemporary clinical trials underline the pivotal role of platelets, coagulation, cholesterol, and systemic inflammation and provide a perspective on a personalized, targeted approach. Emerging data sheds new light on heretofore unrecognized residual risk factors. This review aims to summarize evolving evidence relative to secondary prevention of atherothrombosis, with a focus on recent advances that promise to transform the management of the post-ACS patient.

Association of lowering apolipoprotein B with cardiovascular outcomes across various lipid-lowering therapies: Systematic review and meta-analysis of trials

AIMS

The effect of therapeutic lowering of apolipoprotein B (apoB) on mortality and major adverse cardiovascular events is uncertain. It is also unclear whether these potential effects vary by different lipid-lowering strategies.

METHODS

A total of 29 randomized controlled trials were selected using PubMed, Cochrane Library and EMBASE through 2018. We selected trials of therapies which ultimately clear apolipoprotein B particles by upregulating low-density lipoprotein receptor (LDL-R) expression (statins, ezetimibe, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, bile acid sequestrants) or therapies which reduce apolipoprotein B independent of LDL-R (cholesteryl ester transfer protein inhibitor, fibrates, niacin, omega-3 fatty acids) with sample size of ≥1000 patients and follow-up of ≥1 year. The meta-regression and meta-analyses were constructed using a random effects model.

RESULTS

In 332,912 patients, meta-regression analyses showed relative risks of 0.95 for all-cause mortality (95% confidence interval 0.92-0.99) and 0.93 (0.88-0.98) for cardiovascular mortality for every 10 mg/dL decrease in apolipoprotein B by all interventions combined. Reduction in all-cause mortality was limited to statins (0.92 (0.86-0.98)). For MACE, the relative risk per 10 mg/dL reduction in apolipoprotein B was 0.93 (0.90-0.97) for all therapies combined, with both statin (0.88 (0.83-0.93)) and non-statin therapies (0.96 (0.94-0.99)). which clear apolipoprotein B by upregulating LDL-R showing significant reductions; whereas interventions which lower apolipoprotein B independent of LDL-R did not demonstrate this effect (1.02 (0.81-1.30)).

CONCLUSION

While both statin and established non-statin therapies (PCSK9 inhibitor and ezetimibe) reduced cardiovascular risk per decrease in apolipoprotein B, interventions which reduce apolipoprotein B independently of LDL-R were not associated with cardiovascular benefit.

Effects of PCSK9 inhibitors on LDL cholesterol, cardiovascular morbidity and all-cause mortality: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors determine a wide reduction of LDL cholesterol, greater than other lipid-lowering agents. The present meta-analysis is aimed at the assessment of PCSK9 inhibitors effect on LDL Cholesterol, cardiovascular morbidity and all-cause mortality.

METHODS AND RESULTS

A Medline and Clinicaltrials.gov search for eligible studies until December 1, 2017, was performed. All randomized trials (> 12 weeks) comparing PCSK-9 inhibitors with placebo or active drugs were retrieved. Primary endpoints: (a) LDL cholesterol at endpoint; (b) Major cardiovascular events (MACE); (c) All-cause mortality. Data extraction was performed independently by two of the authors, and conflicts resolved by a third investigator. A total of 38 trials fulfilling the inclusion criteria were identified, with mean duration of 36.4 weeks. The reduction of LDL cholesterol at endpoint, versus placebo, ezetimibe, and high-dose statins was - 65.3 [- 69.6, - 60.9]%, - 57.7 [- 68.3;- 47.0]%, and - 34.5 [- 40.8;- 28.1]%, respectively, with alirocumab possibly showing a smaller effect than the other drugs of the class. Treatment with PCSK9 inhibitors was associated with a reduction in the incidence of MACE (Mantel-Haenszel Odds Ratio [MH-OR] 0.83 [0.78, 0.88]), with significant effects of alirocumab and evolocumab only. The number needed to treat for 2 years for preventing one event was 89. All-cause mortality and cardiovascular mortality were not reduced by treatment with PCSK-9 inhibitors (MH-OR 0.94 [0.84, 1.04] and 0.97[0.86;1.09]).

CONCLUSIONS

PCSK-9 inhibitors are effective in reducing LDL cholesterol and the incidence of major cardiovascular events in high-risk patients. Bococizumab does not show significant effects on MACE.

REGISTRATION NUMBER

PROSPERO-CRD42018087640.

Treat stroke to target trial design: First trial comparing two LDL targets in patients with atherothrombotic strokes

BACKGROUND

In patients with non-cardio-embolic stroke, atorvastatin 80 mg/day reduced the relative risk of recurrent stroke by 16%, and a post hoc analysis showed that achieving an LDL-c of less than 70 mg/dL reduced the relative risk by 28% as compared to an on-treatment LDL of 100 mg/dL or more. Current guidelines from the French drug agency recommend treating with a statin after an ischaemic stroke to a target of less than 100 mg/dL, but no study directly tested LDL-c targets. The Treat Stroke to Target (TST) trial will compare the efficacy of achieving an LDL-c of less than 70 mg/dL versus an achieved LDL-c of 100 ± 10 mg/dL for secondary prevention in patients with recent ischaemic stroke of atherosclerotic origin.Main hypothesis: An achieved on-treatment LDL-c of less than 70 mg/dL will reduce by 25% the risk of recurrent ischaemic stroke, myocardial infarction, urgent coronary or carotid revascularisation following new symptoms requiring hospitalisation, and vascular death compared with on-treatment LDL-c of 100 ± 10 mg/dL.

DESIGN

Patients are randomised to either LDL-c levels, and the investigator who is not blinded can use the lipid-lowering agent of his/her choice available on the market (including statins and ezetimibe), in order to achieve the assigned LDL-c level. To be eligible for enrolment, patients have a recent ischaemic stroke or TIA of atherosclerotic origin with at least one arterial stenosis of a cerebral artery, enrolled between acute phase of the qualifying stroke (once the neurological deficit is stabilised) and three months. The initial planned sample size of 3760 participants followed three years was amended to allow follow-up of all enrolled patients until 385 primary efficacy outcome events have occurred, and no later than 31 December 2019. Patients will be recruited in 76 sites in two countries (France and South Korea) between March 2010 and December 2018 (last included patient followed up to one year). Safety outcomes will include haemorrhagic strokes and new onset diabetes. All primary endpoints will be adjudicated by an endpoint committee, blinded to the assigned LDL-c level. Two sub-studies assess (1) the relative effect of assigned LDL-c levels on occurrence of new atherosclerotic plaque as detected by carotid ultrasound during follow-up, using M'ATH software for repositioning and (2) the genetic and biomarker drivers of recurrent primary endpoints according to assigned LDL-c lowering arm, in atherosclerotic strokes.

SUMMARY

The TST trial is evaluating the benefits of achieving an LDL-c less than 70 mg/dL for secondary stroke prevention in ischaemic stroke patients of atherosclerotic origin. Main results are anticipated in 2020 or earlier (ClinicalTrials.gov NCT01252875).

Shifting Paradigms Revisited: Biotechnology and the Pharmaceutical Sciences

In 2003, Crommelin et al. published an article titled: "Shifting paradigms: biopharmaceuticals versus low molecular weight drugs" (https://doi.org/10.1016/S0378-5173(03)00376-4). In the present commentary, 16 years later, we discuss pharmaceutically relevant aspects of the evolution of biologics since then. First, we discuss the increasing repertoire of biologics, in particular, the rapidly growing monoclonal antibody family and the advent of advanced therapy medicinal products. Next, we discuss trends in formulation and characterization as well as summarize our current insights into immunogenicity of biologics. We spend a separate section on new product(ion) paradigms for biologics, such as cell-free production systems, production of advanced therapy medicinal products, and downscaled production approaches. Furthermore, we share our views on issues related to reaching the patient, including routes and techniques of administration, alternative development models for affordable biologics, biosimilars, and handling of biologics. In the concluding section, we outline outstanding issues and make some suggestions for resolving those.

Atherosclerosis

Atherosclerosis, the formation of fibrofatty lesions in the artery wall, causes much morbidity and mortality worldwide, including most myocardial infarctions and many strokes, as well as disabling peripheral artery disease. Development of atherosclerotic lesions probably requires low-density lipoprotein, a particle that carries cholesterol through the blood. Other risk factors for atherosclerosis and its thrombotic complications include hypertension, cigarette smoking and diabetes mellitus. Increasing evidence also points to a role of the immune system, as emerging risk factors include inflammation and clonal haematopoiesis. Studies of the cell and molecular biology of atherogenesis have provided considerable insight into the mechanisms that link all these risk factors to atheroma development and the clinical manifestations of this disease. An array of diagnostic techniques, both invasive (such as selective coronary arteriography) and noninvasive (such as blood biomarkers, stress testing, CT and nuclear scanning), permit assessment of cardiovascular disease risk and targeting of therapies. An expanding armamentarium of therapies that can modify risk factors and confer clinical benefit is available; however, we face considerable challenge in providing equitable access to these treatments and in maximizing adherence. Yet, the clinical application of the fruits of research has advanced preventive strategies, enhanced clinical outcomes in affected individuals, and improved their quality of life. Rapidly accelerating knowledge and continued research promise to provide further progress in combating this common chronic disease.

Effect of coexisting vascular disease on long-term risk of recurrent events after TIA or stroke

OBJECTIVE

To determine whether patients with TIA or ischemic stroke with coexisting cardiovascular disease (i.e., history of coronary or peripheral artery disease) are still at high risk of recurrent ischemic events despite current secondary prevention guidelines.

METHODS

In a population-based study in Oxfordshire, UK (Oxford Vascular Study), we studied consecutive patients with TIA or ischemic stroke for 2002-2014. Patients were treated according to current secondary prevention guidelines and we determined risks of coronary events, recurrent ischemic stroke, and major bleeding stratified by the presence of coexisting cardiovascular disease.

RESULTS

Among 2,555 patients (9,148 patient-years of follow-up), those (n = 640; 25.0%) with coexisting cardiovascular disease (449 coronary only; 103 peripheral only; 88 both) were at higher 10-year risk of coronary events than those without (22.8%, 95% confidence interval 17.4-27.9; vs 7.1%, 5.3-8.8; p < 0.001; age- and sex-adjusted hazard ratio [HR] 3.07, 2.24-4.21) and of recurrent ischemic stroke (31.5%, 25.1-37.4; vs 23.4%, 20.5-26.2; p = 0.0049; age- and sex-adjusted HR 1.23, 0.99-1.53), despite similar rates of use of antithrombotic and lipid-lowering medication. However, in patients with noncardioembolic TIA/stroke, risk of extracranial bleeds was also higher in those with coexisting cardiovascular disease, particularly in patients aged <75 years (8.1%, 2.8-13.0; vs 3.4%, 1.6-5.3; p = 0.0050; age- and sex-adjusted HR 2.71, 1.16-6.30), although risk of intracerebral hemorrhage was not increased (age- and sex-adjusted HR 0.36, 0.04-2.99).

CONCLUSIONS

As in older studies, patients with TIA/stroke with coexisting cardiovascular disease remain at high risk of recurrent ischemic events despite current management. More intensive lipid-lowering might therefore be justified, but benefit from increased antithrombotic treatment might be offset by the higher risk of extracranial bleeding.

An update on trials of novel lipid-lowering drugs

PURPOSE OF REVIEW

A number of novel trials have assessed the efficacy of new lipid-lowering therapies in cardiovascular disease (CVD).

RECENT FINDINGS

Proprotein convertase subtilisin kexin-9 inhibitors reduce low-density lipoprotein cholesterol (LDL-C) by 50-55%. A CVD outcome trial in patients with acute coronary syndromes with evolocumab achieved a LDL-C of 0.8 mmol/l (31 mg/dl) and a 20% relative risk reduction in CVD events in 2.2 years. Cholesterol ester transfer protein inhibitors raise high-density lipoprotein cholesterol and can lower LDL-C. Anacetrapib reduced coronary artery disease events by 7%, but not wider composite CVD outcomes, in a population with chronic CVD with pretreatment LDL-C of 1.6 mmol/l (62 mg/dl). The conflicting outcomes of cholesterol ester transfer protein inhibitor trials means these compounds are not being developed further. Trials using lipid drugs targeting inflammation have previously been generally unsuccessful, but recent data on the interleukin-1B receptor antagonist canakinumab has proven the concept of intervention on inflammation in atherosclerosis by showing a reduction in acute coronary interventions, but at the predictable cost of increased infections.

SUMMARY

Despite the success of proprotein convertase subtilisin kexin-9 inhibition, the ability to achieve low LDL-C with off-patent medications and the costs of novel therapies will limit their use even in high-risk patients and confine them to the highest-risk sub-groups of patients.

PCSK9 Inhibitors in a Statin-Intolerant Transgender Man With Heterozygous Familial Hypercholesterolemia: A Case Report

In female-to-male transgender individuals, testosterone is used to induce masculinization. Sex steroid therapy may increase circulating triglyceride and low-density lipoprotein cholesterol (LDL-C) levels and may decrease high-density lipoprotein cholesterol (HDL-C) levels, resulting in a more atherogenic lipid profile. These potentially adverse effects of androgen therapy may be exacerbated by the presence of familial hypercholesterolemia (FH). We describe the case of a transgender man with genetically diagnosed FH who was intolerant to statins and was started on a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor to control his lipoproteins more effectively.

The 35-year-old female-to-male transgender individual was referred to our center with a history of elevated LDL-C levels. Despite treatment with high doses of high-potency statins and ezetimibe, he had never achieved a sustained reduction in LDL-C; his levels of LDL-C were fluctuating between 170 and 344 mg/dL (4.4 and 8.9 mmol/L). Moreover, he developed side effects to statins in the form of myalgia and discontinued statin treatment. At the Sahlgrenska Lipid Clinic, a genetic diagnosis of heterozygous FH was established, and PCSK9 inhibitor therapy was started. The patient’s LDL-C level has been reduced by approximately 40% for 23 months, and no adverse events have been reported.

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

BACKGROUND

To evaluate the effects of proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors on major adverse cardiovascular events (MACE).

METHODS

Our systematic review included randomised controlled trials if they studied PCSK9 inhibitors in patients for primary and/or secondary prevention of cardiovascular diseases or with hypercholesterolaemia/hyperlipidaemia. Dichotomous variables from individual studies were pooled by relative risks (RR) and their 95% CIs using the random-effect model. Risk difference (RD) in the 10-year frame was also estimated using the pooled RR and the estimated baseline risk using the control group. Grading of Recommendation Assessment, Development and Evaluation was used to assess the quality of evidence.

RESULTS

We included 54 trials with 97 910 patients in the analysis. Compared with controls, PCSK9 inhibitors significantly reduced the risk of MACE by 16% (RR, 0.84; 95% CI 0.79 to 0.89; RD: 47 fewer per 1000 vs 286 as the baseline risk; 95% CI 32 to 59 fewer), non-fatal myocardial infarction (MI) by 17% (RR, 0.83; 95% CI 0.74 to 0.93; RD, 35 fewer per 1000 vs 207 as the baseline; 95% CI 13 to 53 fewer) and any stroke by 25% (RR, 0.75; 95% CI 0.65 to 0.85; RD, 16 fewer per 1000 vs 61 as the baseline; 95% CI 9 to 21 fewer) with moderate quality evidence. No significant differences were found between PCSK9 inhibitors and control groups in all-cause mortality, cardiovascular death, heart failure or unstable angina with low-quality evidence.

CONCLUSIONS

This study demonstrated that PCSK9 inhibitors could significantly reduce the risk of MACE, non-fatal MI and stroke.

TRIAL REGISTRATION

PROSPERO; CRD42017073904.

Effects of alirocumab on cardiovascular and metabolic outcomes after acute coronary syndrome in patients with or without diabetes: a prespecified analysis of the ODYSSEY OUTCOMES randomised controlled trial

BACKGROUND

After acute coronary syndrome, diabetes conveys an excess risk of ischaemic cardiovascular events. A reduction in mean LDL cholesterol to 1·4-1·8 mmol/L with ezetimibe or statins reduces cardiovascular events in patients with an acute coronary syndrome and diabetes. However, the efficacy and safety of further reduction in LDL cholesterol with an inhibitor of proprotein convertase subtilisin/kexin type 9 (PCSK9) after acute coronary syndrome is unknown. We aimed to explore this issue in a prespecified analysis of the ODYSSEY OUTCOMES trial of the PCSK9 inhibitor alirocumab, assessing its effects on cardiovascular outcomes by baseline glycaemic status, while also assessing its effects on glycaemic measures including risk of new-onset diabetes.

METHODS

ODYSSEY OUTCOMES was a randomised, double-blind, placebo-controlled trial, done at 1315 sites in 57 countries, that compared alirocumab with placebo in patients who had been admitted to hospital with an acute coronary syndrome (myocardial infarction or unstable angina) 1-12 months before randomisation and who had raised concentrations of atherogenic lipoproteins despite use of high-intensity statins. Patients were randomly assigned (1:1) to receive alirocumab or placebo every 2 weeks; randomisation was stratified by country and was done centrally with an interactive voice-response or web-response system. Alirocumab was titrated to target LDL cholesterol concentrations of 0·65-1·30 mmol/L. In this prespecified analysis, we investigated the effect of alirocumab on cardiovascular events by glycaemic status at baseline (diabetes, prediabetes, or normoglycaemia)-defined on the basis of patient history, review of medical records, or baseline HbA_1c or fasting serum glucose-and risk of new-onset diabetes among those without diabetes at baseline. The primary endpoint was a composite of death from coronary heart disease, non-fatal myocardial infarction, fatal or non-fatal ischaemic stroke, or unstable angina requiring hospital admission. ODYSSEY OUTCOMES is registered with ClinicalTrials.gov, number NCT01663402.

FINDINGS

At study baseline, 5444 patients (28·8%) had diabetes, 8246 (43·6%) had prediabetes, and 5234 (27·7%) had normoglycaemia. There were no significant differences across glycaemic categories in median LDL cholesterol at baseline (2·20-2·28 mmol/L), after 4 months' treatment with alirocumab (0·80 mmol/L), or after 4 months' treatment with placebo (2·25-2·28 mmol/L). In the placebo group, the incidence of the primary endpoint over a median of 2·8 years was greater in patients with diabetes (16·4%) than in those with prediabetes (9·2%) or normoglycaemia (8·5%); hazard ratio (HR) for diabetes versus normoglycaemia 2·09 (95% CI 1·78-2·46, p<0·0001) and for diabetes versus prediabetes 1·90 (1·65-2·17, p<0·0001). Alirocumab resulted in similar relative reductions in the incidence of the primary endpoint in each glycaemic category, but a greater absolute reduction in the incidence of the primary endpoint in patients with diabetes (2·3%, 95% CI 0·4 to 4·2) than in those with prediabetes (1·2%, 0·0 to 2·4) or normoglycaemia (1·2%, -0·3 to 2·7; absolute risk reduction p_interaction=0·0019). Among patients without diabetes at baseline, 676 (10·1%) developed diabetes in the placebo group, compared with 648 (9·6%) in the alirocumab group; alirocumab did not increase the risk of new-onset diabetes (HR 1·00, 95% CI 0·89-1·11). HRs were 0·97 (95% CI 0·87-1·09) for patients with prediabetes and 1·30 (95% CI 0·93-1·81) for those with normoglycaemia (p_interaction=0·11).

INTERPRETATION

After a recent acute coronary syndrome, alirocumab treatment targeting an LDL cholesterol concentration of 0·65-1·30 mmol/L produced about twice the absolute reduction in cardiovascular events among patients with diabetes as in those without diabetes. Alirocumab treatment did not increase the risk of new-onset diabetes.

FUNDING

Sanofi and Regeneron Pharmaceuticals.

Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) Inhibitors, Reality or Dream in Managing Patients with Cardiovascular Disease

BACKGROUND

Statins have been a major keystone in the management of patients with atherosclerotic cardiovascular disease. The benefits of inhibiting HMG CoA reductase, via statins, were translated into reduction in LDL-c with proportionate decrease in cardiovascular events in response to the magnitude of LDL-c reduction. Despite major advances in pharmacological treatments, including the use of high-dose statins, there are urgent need to further reduce future cardiovascular risk. This is in particularly important since 1 out of 5 high-risk atherosclerotic patients who achieve low LDL-c return with a second cardiovascular event within five years. Although this residual risk post-statin is largely heterogeneous, lowering LDL-c beyond 'normal' or guidelines-recommended level using novel therapies has resulted in further reduction in cardiovascular events.

OBJECTIVE

The current review will discuss the use of PCSK9 inhibitors in patients with atherosclerotic disease. PCSK9 inhibitors are a new class of lipid-lowering drugs that are either fully human monoclonal antibodies (evolocumab and alirocumab) or humanised monoclonal antibodies (bococizumab) that effectively reduce LDL-c to unprecedented level. By blocking circulating PCSK9, these drugs would preserve LDL receptors and prevent them from cellular degradation. This process promotes recycling of LDL receptors back to hepatocytes surface, leading into further reduction of LDL-c. Combining PCSK9 inhibitors with statin have led into lower LDL-c, reduction in plaque volume and more importantly reduction in future cardiovascular events.

CONCLUSION

These drugs are very promising, nonetheless, the unselective approach of applying these monoclonal antibodies may not prove to be cost-effective and potentially exposing some patients to unnecessary side effects.

Effect of Access to Prescribed PCSK9 Inhibitors on Cardiovascular Outcomes

Supplemental Digital Content is available in the text.

Atherosclerotic cardiovascular disease remains a major cause of death and disability, especially for high-risk familial hypercholesterolemia individuals. PCSK9i (proprotein convertase subtilisin kexin type 9 inhibitors) reduce low-density lipoprotein cholesterol levels and cardiovascular event rates. However, PCSK9i prescriptions are rejected at high rates by payers, and use is often delayed or eventually abandoned as a treatment option. We tested the hypothesis that acute coronary syndromes, coronary interventions, stroke, and cardiac arrest are more prevalent in patients with rejected or abandoned PCSK9i prescriptions than for those with paid PCSK9i prescriptions.

Practical guide for the use of PCSK9 inhibitors in Portugal

Reducing low-density lipoprotein cholesterol (LDL-C) levels is one of the most important strategies for reducing the risk of cardiovascular events. However, in clinical practice, a high proportion of patients do not achieve recommended LDL-C levels through lifestyle and lipid-lowering therapy with statins and ezetimibe. PCSK9 inhibitors (PCSK9i) are a new therapeutic option that significantly (50-60%) reduces LDL-C levels, which in clinical trials translates into an additional reduction in risk for cardiovascular events, and has a good safety profile. However, it is a high-cost therapy, and therefore its use in clinical practice should take its cost-effectiveness into account. Priority should be given to use in patients at higher cardiovascular risk and those in whom high LDL-C levels persist despite optimal lipid-lowering therapy. This consensus document aims to summarize the main data on the clinical use of PCSK9i and to make recommendations for Portugal on the profile of patients who may benefit most from this therapy.

Impact of Lipid-Lowering Therapy on Mortality According to the Baseline Non-HDL Cholesterol Level: A Meta-Analysis

INTRODUCTION

Previous report showed that more intensive lipid-lowering therapy was associated with less mortality when baseline LDL-C levels were > 100 mg/dL. Non-HDL-C is a better predictor of cardiovascular risk than simpler LDL-C.

AIM

The objective of this meta-analysis was to define the impact of lipid-lowering therapy on the reduction of total and cardiovascular mortality by different baseline levels of non-HDL-C.

METHODS

We performed a meta-analysis including randomized, controlled clinical trials of lipid-lowering therapy, reporting mortality with a minimum of 6 months of follow-up, searching in PubMed/Medline, EMBASE and Cochrane Clinical Trials databases. The random-effects model and meta-regression were performed.

RESULTS

Twenty nine trials of lipid-lowering drugs, including 233,027 patients, were considered eligible for the analyses. According to the baseline non-HDL-C level, the results on cardiovascular mortality were: (1) ≥ 190 mg/dL: OR 0.63 (95% CI 0.53-0.76); (2) 160-189 mg/dL: OR 0.82 (95% CI 0.75-0.89); (3) 130-159 mg/dL: OR 0.71 (95% CI 0.52-0.98); (4) < 130 mg/dL: OR 0.95 (95% CI 0.87-1.05). When evaluating mortality from any cause, the results were the following: (1) ≥ 190 mg/dL: OR 0.70 (95% CI 0.61-0.82); (2) 160-189 mg/dL: OR 0.91 (95% CI 0.83-0.98); (3) 130-159 mg/dL; OR 0.88 (95% CI 0.77-1.00); (4) < 130 mg/dL: OR 0.98 (95% CI 0.91-1.06). The meta-regression analysis showed a significant association between baseline non-HDL-C and mortality.

CONCLUSIONS

In these meta-analyses, lipid-lowering therapy was associated with reduction in the risk of all-cause and cardiovascular mortality when baseline non-HDL-C levels were above than 130 mg/dL.

Targeting CD40-Induced TRAF6 Signaling in Macrophages Reduces Atherosclerosis

Background

Disrupting the costimulatory CD40-CD40L dyad reduces atherosclerosis, but can result in immune suppression. The authors recently identified small molecule inhibitors that block the interaction between CD40 and tumor necrosis factor receptor-associated factor (TRAF) 6 (TRAF-STOPs), while leaving CD40-TRAF2/3/5 interactions intact, thereby preserving CD40-mediated immunity.

Objectives

This study evaluates the potential of TRAF-STOP treatment in atherosclerosis.

Methods

The effects of TRAF-STOPs on atherosclerosis were investigated in apolipoprotein E deficient (Apoe^−/−) mice. Recombinant high-density lipoprotein (rHDL) nanoparticles were used to target TRAF-STOPs to macrophages.

Results

TRAF-STOP treatment of young Apoe^−/− mice reduced atherosclerosis by reducing CD40 and integrin expression in classical monocytes, thereby hampering monocyte recruitment. When Apoe^−/− mice with established atherosclerosis were treated with TRAF-STOPs, plaque progression was halted, and plaques contained an increase in collagen, developed small necrotic cores, and contained only a few immune cells. TRAF-STOP treatment did not impair “classical” immune pathways of CD40, including T-cell proliferation and costimulation, Ig isotype switching, or germinal center formation, but reduced CD40 and β2-integrin expression in inflammatory monocytes. In vitro testing and transcriptional profiling showed that TRAF-STOPs are effective in reducing macrophage migration and activation, which could be attributed to reduced phosphorylation of signaling intermediates of the canonical NF-κB pathway. To target TRAF-STOPs specifically to macrophages, TRAF-STOP 6877002 was incorporated into rHDL nanoparticles. Six weeks of rHDL-6877002 treatment attenuated the initiation of atherosclerosis in Apoe^−/− mice.

Conclusions

TRAF-STOPs can overcome the current limitations of long-term CD40 inhibition in atherosclerosis and have the potential to become a future therapeutic for atherosclerosis.

Update of therapeutic planning tables oriented towards obtaining therapeutic objectives

This is the fourth update of the therapeutic planning tables. These tables are a simple desktop tool, to help in determining the most appropriate oral cholesterol-lowering therapy for patient. This can either be with monotherapy or combination therapy (statins plus ezetimibe), taking into account the patient LDL cholesterol (LDL-C) and the therapeutic objective to be achieved. These therapeutic indications are based on 2 fundamental principles: the causality of LDL-C, and that the effect of cardiovascular protection depends on the decrease in LDL-C. It is based on a colour code that indicates the drugs that have the necessary power to meet the therapeutic objectives of the patient. We provide some recommendations on the strategy to follow to implement the most effective treatment. It is assessed up to what levels a decrease in LDL-C can be expected by adding a PCSK9 inhibitor.

Structure and Function of Proprotein Convertase Subtilisin/kexin Type 9 (PCSK9) in Hyperlipidemia and Atherosclerosis

Background:

One of the important factors in Low-Density Lipoprotein (LDL) metabolism is the LDL receptor (LDLR) by its capacity to bind and subsequently clear cholesterol derived from LDL (LDL-C) in the circulation. Proprotein Convertase Subtilisin-like Kexin type 9 (PCSK9) is a newly discovered serine protease that destroys LDLR in the liver and thereby controls the levels of LDL in plasma. Inhibition of PCSK9-mediated degradation of LDLR has, therefore, become a novel target for lipid-lowering therapy.

Methods:

We review the current understanding of the structure and function of PCSK9 as well as its implications for the treatment of hyperlipidemia and atherosclerosis.

Results:

New treatments such as monoclonal antibodies against PCSK9 may be useful agents to lower plasma levels of LDL and hence prevent atherosclerosis.

Conclusion:

PCSK9's mechanism of action is not yet fully clarified. However, treatments that target PCSK9 have shown striking early efficacy and promise to improve the lives of countless patients with hyperlipidemia and atherosclerosis.

Association of baseline LDL-C with total and cardiovascular mortality in patients using proprotein convertase subtilisin-kexin type 9 inhibitors: A systematic review and meta-analysis

BACKGROUND

The objective of this study was to investigate whether baseline low-density lipoprotein cholesterol (LDL-C) levels influence total and cardiovascular mortality reduction associated with proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitor therapy.

METHODS

In this meta-analysis, 9 randomized controlled trials were selected using Medline, Embase, and CENTRAL until November 2018. Analyses were stratified by mean baseline LDL-C (<100 mg/dL and ≥ 100 mg/dL). Stepwise prespecified sensitivity analyses were performed after excluding the SPIRE trials and by regrouping ODYSSEY OUTCOME mortality data according to the baseline LDL-C (< and ≥100 mg/dL).

RESULTS

In 83,321 patients, PCSK9 inhibitor therapy was not associated with a reduction in the risk of all-cause mortality (relative risk [RR], 0.94, 95% confidence interval [CI], 0.81-1.09, P = .41). These results remained consistent after excluding the SPIRE trials (RR, 0.89, 95% CI, 0.75-1.05, P = .18). However, the RR varied by baseline LDL-C, with significant RR reduction only in patients with LDL-C ≥ 100 mg/dL (RR, 0.39, 95% CI, 0.20-0.76) (P-interaction = .01). Meta-regression showed RR of 0.97 for all-cause mortality per 1 mg/dL higher baseline LDL-C (95% CI, 0.94-0.99). PCSK9 inhibitor therapy showed no significant effect on cardiovascular mortality, with no effect when excluding the SPIRE trials. However, after regrouping ODYSSEY OUTCOME estimates, there was a significant reduction in cardiovascular mortality restricted to patients with LDL-C ≥ 100 mg/dL (RR, 0.67, 95% CI, 0.51-0.87) (P-interaction = .006).

CONCLUSION

PCSK9 inhibitor therapy on a background statin treatment may reduce the risk of total and cardiovascular mortality in patients with baseline LDL-C ≥ 100 mg/dL. These results support current guidelines reserving PCSK9 inhibitors for high-risk patients with residually high LDL-C.

Proprotein convertase subtilisin/kexin type 9 in kidney disease

Chronic kidney disease (CKD) is associated with a substantially increased risk for the development of atherosclerotic cardiovascular (CV) disease. Accordingly, CV mortality is increased even in the earliest stages of CKD. In the general population and in CKD patients, high plasma levels of low-density lipoprotein cholesterol (LDL-C) are crucially involved in the initiation and progression of atherosclerotic vascular lesions. Lowering LDL-C by use of statins and/or ezetimibe represents the gold standard of lipid-lowering therapy, with a great body of evidence from several large clinical trials. Statin therapy reduces CV events in patients with normal and impaired kidney function alike, while the evidence for patients on maintenance haemodialysis is weaker. The inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) serine protease represents a novel lipid-lowering tool. Currently the monoclonal antibodies evolocumab and alirocumab are the approved PCSK9 inhibitors. Despite maximum-tolerated statin therapy, they efficiently further reduce LDL-C plasma levels without any major adverse effects. Moreover, in large clinical outcome trials, both antibodies have been proven to lower CV events. Notably, the LDL-lowering capacity was independent of baseline kidney function and also efficient in patients with moderate CKD. However, patients with severely impaired kidney function, that is, the population at the highest CV risk, have been excluded from those trials. The relevance of the LDL-independent effects of PCSK9 inhibitors, such as lowering lipoprotein(a) or ameliorating dyslipidaemia in patients with nephrotic syndrome, has to be determined. Therefore further specific studies assessing the effects and outcomes of PCSK9-inhibiting treatment in CKD patients are warranted.

Biologics and Cardiovascular Disease

The advent of biologic therapy has enhanced our ability to augment disease in an increasingly targeted manner. The use of biologics in cardiovascular disease (CVD) has steadily increased over the past several decades. Much of the early data on biologics and CVD were derived from their use in rheumatologic populations. Atherosclerosis, myocardial infarction, and heart failure have been closely linked to the inflammatory response. Accordingly, cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 have been targeted. Noninflammatory mediators, such as proprotein convertase subtilisin kexin type 9 (PCSK9), have been selected for therapeutic intervention as well. Furthermore, RNA interference (RNAi) therapy has emerged and may serve as another targeted therapeutic mechanism. Herein, we will review the history, obstacles, and advances in using biologic therapy for CVD.

Proprotein convertase subtilisin/kexin type 9: from genetics to clinical trials

PURPOSE OF REVIEW

This review describes the pivotal role of genetic insights and technologies in the discovery of proprotein convertase subtilisin/kexin type 9 (PCSK9) and the rapid development of PCSK9 inhibitors - a revolutionary new class of lipid-lowering agents.

RECENT FINDINGS

PCSK9 was discovered as a the third gene implicated in familial hypercholesterolemia. Population genetics studies, enabled by technological advances, were instrumental in validating PCSK9 as a therapeutic target. Monoclonal antibodies against PCSK9 were introduced in the clinic after an unprecedently rapid development path, in which clinical trial results confirmed that these drugs robustly lower cholesterol and improve clinical outcomes regardless of disease indication or background therapy. New strategies to PCSK9 inhibition are underway and have delivered promising preliminary results, including inhibition of PCSK9 synthesis by targeting the cellular gene expression machinery and vaccination. The future will tell whether directly targeting the genome through editing techniques will ultimately enable us to virtually eliminate many of the traditional CVD risk factors.

SUMMARY

The extraordinary PCSK9 narrative highlights the opportunities offered by genetics-driven drug development and holds valuable lessons for future development programs.

Relative Effect of Current Intensive Lipid-Lowering Drugs on Cardiovascular Outcomes in Secondary Prevention - A Meta-Analysis of 12 Randomized Trials

BACKGROUND

We aimed to investigate the comparative cardiovascular benefits of high-dose statin, ezetimibe-statin, and PCSK9 inhibitor-statin treatments in secondary prevention patients.

METHODS AND RESULTS

We selected 12 randomized controlled trials (n=131,978 patients) using PubMed and Embase (inception-June 1, 2018). Subgroup differences were explored by meta-regression and Cochran Q test. The relative effects of high-dose statin, ezetimibe-statin, and PCSK9 inhibitor-statin on major cardiovascular events (MACE), and revascularization were varied and decreased gradually, of which high-dose statin resulted in lower risk of MACE and revascularization than PCSK9 inhibitor-statin per 1 mmol/L reduction of low-density lipoprotein cholesterol (LDL-C): risk ratio (RR) for MACE, 0.86 (95% confidence interval (CI), 0.81-0.90) for high-dose statin, 0.90 (95% CI, 0.83-0.96) for ezetimibe-statin, and 0.94 (95% CI, 0.92-0.96) for PCSK9 inhibitor-statin; RR for revascularization, 0.84 (95% CI, 0.77-0.90) for high-dose statin, 0.91 (95% CI, 0.81-1.00) for ezetimibe-statin, and 0.94 (95% CI, 0.90-0.97) for PCSK9 inhibitor-statin. Similar relative effects of intensive lipid-lowering treatment were also observed in analyses of myocardial infarction and stroke, although no significant difference between groups was identified.

CONCLUSIONS

In secondary prevention patients, the relative benefits of high-dose statin, ezetimibe-statin, and PCSK9 inhibitor-statin treatments were varied and decreased gradually, of which high-dose statin was significantly superior to PCSK9 inhibitor-statin for improving MACE and revascularization per 1 mmol/L reduction of LDL-C.

Indications of PCSK9 inhibitors in clinical practice. Recommendations of the Spanish Sociey of Arteriosclerosis (SEA), 2019

A group of experts convened by the Spanish Society of Arteriosclerosis (SEA) has been in charge of updating the SEA document on the indications of PCSK9 inhibitors (PCSK9i) in clinical practice that was published in 2016. This update is justified by the fact that the data from clinical trials carried out on a large scale with PCSK9i have shown that in addition to their high potency to lower atherogenic cholesterol, they reduce the risk of atherosclerotic cardiovascular disease, both in patients with stable disease, and with recent disease, and with a high degree of security. This update provides the recommendations and level of evidence for the prescription of iPCSK9 in patients with homozygous and heterozygous familial hypercholesterolemia, with atherosclerotic cardiovascular disease, and in primary prevention in patients with very high cardiovascular risk. These recommendations have been established taking into account the concentration of LDL-C, the clinical situation of the patient, the additional risk factors and the cost-effectiveness of their use.

Effect of Alirocumab on Mortality After Acute Coronary Syndromes

Supplemental Digital Content is available in the text.

Background:

Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome.

Methods:

ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death.

Results:

Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; P_interaction=0.007). In the alirocumab group, all-cause death declined with achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend).

Conclusions:

Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402.

Effects of Non-statin Lipid-Modifying Agents on Cardiovascular Morbidity and Mortality Among Statin-Treated Patients: A Systematic Review and Network Meta-Analysis

Background: Currently, there is a lack of information on the comparative efficacy and safety of non-statin lipid-lowering agents (NST) in cardiovascular (CV) disease risk reduction when added to background statin therapy (ST). This study determine the relative treatment effects of NST on fatal and non-fatal CV events among statin-treated patients.

Methods: A network meta-analysis based on a systematic review of randomized controlled trials (RCTs) comparing non-statin lipid-modifying agents among statin-treated patients was performed. PubMed, EMBASE, CENTRAL, and Clinicaltrial.gov were searched up to April 10, 2018. The primary outcomes were CV and all-cause mortalities. Secondary CV outcomes were coronary heart disease (CHD) death, non-fatal myocardial infarction (MI), any stroke, and coronary revascularization. Risks of discontinuations were secondary safety outcomes.

Results: Sixty-seven RCTs including 259,429 participants with eight interventions were analyzed. No intervention had significant effects on the primary outcomes (CV mortality and all-cause mortality). For secondary endpoints, proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK) plus statin (PCSK/ST) significantly reduced the risk of non-fatal MI (RR 0.82, 95% CI 0.72–0.93, p = 0.003), stroke (RR 0.74, 95% CI 0.65–0.85, p < 0.001), coronary revascularization (RR 0.84, 95% CI 0.75–0.94, p = 0.003) compared to ST. Combinations of ST and all NST except PCSK and ezetimibe showed higher rate of discontinuation due to adverse events compared to ST.

Conclusions: None of NST significantly reduced CV or all-cause death when added to ST. PCSKs and to a lesser extent, ezetimibe may help reduce cardiovascular events with acceptable tolerability profile among broad range of patients.

Proprotein Convertase Subtilisin/Kexin Type 9, Brain Cholesterol Homeostasis and Potential Implication for Alzheimer's Disease

Alzheimer’s disease (AD) has been associated with dysregulation of brain cholesterol homeostasis. Proprotein convertase subtilisin/kexin type 9 (PCSK9), beyond the known role in the regulation of plasma low-density lipoprotein cholesterol, was first identified in the brain with a potential involvement in brain development and apoptosis. However, its role in the central nervous system (CNS) and in AD pathogenesis is still far from being understood. While in vitro and in vivo evidence led to controversial results, genetic studies apparently did not find an association between PCSK9 loss of function mutations and AD risk or prevalence. In addition, a potential impairment of cognitive performances by the treatment with the PCSK9 inhibitors, alirocumab and evolocumab, have been excluded, although ongoing studies with longer follow-up will provide further insights. PCSK9 is able to affect the expression of neuronal receptors involved in cholesterol homeostasis and neuroinflammation, and higher PCSK9 concentrations have been found in the cerebrospinal fluid (CSF) of AD patients. In this review article, we critically examined the science of PCSK9 with respect to its modulatory role of the mechanisms underlying the pathogenesis of AD. In addition, based on literature data, we made the hypothesis to consider brain PCSK9 as a negative modulator of brain cholesterol homeostasis and neuroinflammation and a potential pharmacological target for treatment.

The PCSK9 revolution: Current status, controversies, and future directions

Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) has revolutionized our understanding of cholesterol homeostasis and added to our arsenal against atherosclerotic cardiovascular disease (ASCVD). In a span of approximately 15 years, PCSK9 has morphed from an esoteric and rare cause of familial hypercholesterolemia (FH) into the most efficient cholesterol-lowering target ever known, with the completion of two large scale cardiovascular outcome trials showing positive results. Current Food and Drug Administration (FDA) approved modalities to inhibit PCSK9 are in the form of monoclonal antibodies which display an unparalleled degree of low-density lipoprotein cholesterol (LDL-C) lowering and expand upon the notion that lower LDL-C is better for ASCVD risk reduction. However, the accelerated pace of discovery and therapeutic development has left large gaps in our knowledge regarding the physiology and function of PCSK9. The aim of this review is to provide context to the discovery, history, treatment and current status of PCSK9 and its therapeutic inhibitors and highlight areas of controversy and future directions.

Low-density lipoprotein cholesterol lowering for the prevention of cardiovascular outcomes in patients with ischemic stroke

BACKGROUND

Low-density lipoprotein (LDL) cholesterol has been long associated with the risk for ischemic stroke, myocardial infarction, and cardiovascular death. For more than a decade, the main pharmacological option to prevent stroke and myocardial infarction through LDL-cholesterol lowering was the use of statins. During the recent years, two novel classes of drugs have proven their efficacy and safety to reduce LDL-cholesterol and prevent cardiovascular events in large, well-conducted randomized controlled trials: ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors.

AIMS

The present review summarizes the evidence arising from the latest trials of lipid-lowering treatment for cardiovascular outcomes prevention and discusses their implications for secondary prevention strategies in patients with ischemic stroke.

SUMMARY OF REVIEW

There is strong evidence which confirms the hypothesis that the lower the LDL-cholesterol, the less frequent the cardiovascular events are and underlines the importance of treating our ischemic stroke patients with intensive statin treatment aiming at low LDL-cholesterol levels. The very low levels of LDL cholesterol seem to be safe, even in the mid/long term but longer follow-up data are needed. Currently there are no tools to reliably predict cardiovascular outcomes in the specific population of ischemic stroke patients.

CONCLUSIONS

Stroke physicians should aim for low LDL-cholesterol levels by intensive statin treatment in all ischemic stroke patients. For those patients who are at the highest risk for recurrent stroke or another cardiovascular event and have unacceptable LDL-cholesterol levels despite intensive statin treatment, PCSK9 inhibitors should be considered.

[Are there different responses to different PCSK9 inhibitors?]

The case is presented of a 62-year-old patient who required lipid-lowering therapy with proprotein convertase subtilisin/kexin type9 (PCSK9). It was empirically decided to change one drug to another of the two currently available, obtaining a different response. Our objective is to present our experience and to consider a possible therapeutic option in patients in whom, exceptionally, this could happen.

Trials in "True" Dyslipidemic Patients Are Urged to Reconsider Comprehensive Lipid Management as a Means to Reduce Residual Cardiovascular Risk

Randomized cardiovascular trials aimed to reduce the excessive residual risk in high‐risk patients through a more aggressive low‐density lipoprotein‐cholesterol control or targeting triglycerides or high‐density lipoprotein‐cholesterol levels have shown a null or, at best, limited incremental benefit. In some cases, the treatment produced meaningful effects only in study subgroups. As a consequence, some compounds were withdrawn (e.g., nicotinic acid derivatives and cholesteryl ester transfer protein inhibitors), whereas others (fibrates) are utilized with reluctance due to the low level of evidence‐based data. By reviewing these trials analytically, we identified a common feature that might explain their meager results: most of them involved patients generically at high cardiovascular risk with normal or near normal lipid levels and not patients with “true” dyslipidemia, who would receive the treatment if it were part of usual care. These observations may warrant re‐examining a central criterion of pragmatism, eligibility, in the outline of forthcoming cardiovascular trials with novel lipid‐modifying drugs.

Cardiomyopathy in obesity, insulin resistance and diabetes

The prevalence of obesity, insulin resistance and diabetes is increasing rapidly. Most patients with these disorders have hypertriglyceridaemia and increased plasma levels of fatty acids, which are taken up and stored in lipid droplets in the heart. Intramyocardial lipids that exceed the capacity for storage and oxidation can be lipotoxic and induce non-ischaemic and non-hypertensive cardiomyopathy, termed diabetic or lipotoxic cardiomyopathy. The clinical features of diabetic cardiomyopathy are cardiac hypertrophy and diastolic dysfunction, which lead to heart failure, especially heart failure with preserved ejection fraction. Although the pathogenesis of the cardiomyopathy is multifactorial, diabetic dyslipidaemia and intramyocardial lipid accumulation are the key pathological features, triggering cellular signalling and modifications of proteins and lipids via generation of toxic metabolic intermediates. Most clinical studies have shown no beneficial effect of anti-diabetic agents and statins on outcomes in heart failure patients without atherosclerotic diseases, indicating the importance of identifying underlying mechanisms and early interventions for diabetic cardiomyopathy. Here, we summarize the molecular mechanisms of diabetic cardiomyopathy, with a special emphasis on cardiac lipotoxicity, and discuss the role of peroxisome proliferator-activated receptor α and dysregulated fatty acid metabolism as potential therapeutic targets.

The rate of patients at high risk for cardiovascular disease with an optimal low-density cholesterol level: a multicenter study from Thailand

BACKGROUND

Hypercholesterolemia is a major risk factor for cardiovascular events in patients with established atherosclerotic disease (EAD) and in those with multiple risk factors (MRFs). This study aimed to investigate the rate of optimal low-density lipoprotein (LDL) cholesterol level in a multicenter registry of patients at high risk for cardiovascular events.

METHODS

A multicenter registry of EAD and MRF patients was conducted. Demographic data, medical history, cardiovascular risk factors, anthropometric data, laboratory data, and medications were recorded and analyzed. We classified patients according to target LDL levels based on recommendation by the European Society of Cardiology (ESC) 2011 into Group 1 which is EAD and diabetes or chronic kidney disease (CKD)-target LDL below 70 mg/dL, and Group 2 which is MRF without diabetes or CKD-target LDL below 100 mg/dL. The rate of optimal LDL level in patients with Group 1 and Group 2 was analyzed and stratified according to the treatment pattern of lipid-lowering medications.

RESULTS

A total of 3100 patients were included. Of those, 51.7% were male. Average age was 65.8 ± 9.7 years. Average LDL level was 96.3 ± 32.6 mg/dL. A vast majority (92.7%) received statin and 9.3% received ezetimibe. Optimal LDL level was achieved in 20.3% of patients in Group 1 (LDL < 70 mg/dL), and in 46.6% in Group 2 (LDL < 100 mg/dL). The overall rate of optimal LDL control was 23% since 89.6% of study population belongs to Group 1. The rate of optimal LDL was not different between high and low potency statin. Factors that were associated with optimal LDL control were older age, the presence of coronary artery disease or peripheral artery disease.

CONCLUSIONS

The rates of optimal LDL level were unacceptably low in this study population. As such, a strategy to improve LDL control in high-risk population should be implemented.

Clinical guidance on the contemporary use of proprotein convertase subtilisin/kexin type 9 monoclonal antibodies

There is now significant evidence for the benefits of lowering low-density lipoprotein cholesterol (LDL-c) to reduce the risk of atherosclerotic cardiovascular disease (ASCVD). Although statins are the most widely prescribed lipid-lowering therapy that effectively lower LDL-c, especially in combination with ezetimibe, some patients require adjunctive therapy to further lower LDL-c and mitigate attendant risk of ASCVD. The gap can be filled by proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies whose use is currently supported by two recent cardiovascular outcome studies and new treatment guidelines. We provide an overview of extant studies investigating PCSK9 monoclonal antibodies in various patient populations, an update of the guidelines regarding their use and a case-based discussion.

Tackling Residual Atherosclerotic Risk in Statin-Treated Adults: Focus on Emerging Drugs

Epidemiological studies and meta-analyses have consistently suggested the importance of lowering low-density lipoprotein cholesterol (LDL-C) to reduce cardiovascular (CV) events. However, these studies and mechanistic studies using intracoronary imaging modalities have reported patients who continue to experience CV events or disease progression despite optimal LDL-C levels on statins. These findings, including statin intolerance, have highlighted the importance of exploring additional potential therapeutic targets to reduce CV risk. Genomic insights have presented a number of additional novel targets in lipid metabolism. In particular, proprotein convertase subtilisin/kexin type 9 inhibitors have rapidly developed and recently demonstrated their beneficial impact on CV outcomes. Triglyceride (TG)-rich lipoproteins have been recently reported as a causal factor of atherosclerotic cardiovascular disease (ASCVD). Indeed, several promising TG-targeting therapies are being tested at various clinical stages. In this review, we present the evidence to support targeting atherogenic lipoproteins to target residual ASCVD risk in statin-treated patients.

Drug Therapy of Dyslipidemia in the Elderly

Abnormal lipoprotein metabolism is an important and modifiable risk factor for atherosclerotic cardiovascular disease (ASCVD), which has been shown in numerous studies to lead to adverse cardiovascular outcomes. As cardiovascular disease (CVD) remains the major cause of morbidity and mortality globally, management of dyslipidemia is a key component of primary and secondary risk-reduction strategies. Because ASCVD risk increases with age, as the population ages, many more people-particularly the elderly-will meet guideline criteria for drug treatment. Statins (HMG-CoA reductase inhibitors) have an unequivocal benefit in reducing ASCVD risk across age groups for secondary prevention. However, the benefit of these drugs for primary prevention in those > 75 years of age remains controversial. We strongly believe that statins should be offered for primary prevention to all older individuals after a shared decision-making process that takes polypharmacy, frailty, and potential adverse effects into consideration. When considering statin therapy in the very old, competing risks of death, and therefore the likelihood that patients will live long enough to benefit from drug therapy, should inform this process. Combination therapies with ezetimibe or proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors should be considered to facilitate the use of tolerable doses of statins. Future investigations of dyslipidemia therapies must appropriately include this at-risk population to identify optimal drugs and drug combinations that have a high benefit:risk ratio for the prevention of ASCVD in the elderly.