Lipoprotein(a) and proprotein convertase subtilisin/kexin type 9 inhibitors

Non-stenotic Carotid Plaques in Embolic Stroke of Unknown Source

Embolic stroke of unknown source (ESUS) represents one in five ischemic strokes. Ipsilateral non-stenotic carotid plaques are identified in 40% of all ESUS. In this narrative review, we summarize the evidence supporting the potential causal relationship between ESUS and non-stenotic carotid plaques; discuss the remaining challenges in establishing the causal link between non-stenotic plaques and ESUS and describe biomarkers of potential interest for future research. In support of the causal relationship between ESUS and non-stenotic carotid plaques, studies have shown that plaques with high-risk features are five times more prevalent in the ipsilateral vs. the contralateral carotid and there is a lower incidence of atrial fibrillation during follow-up in patients with ipsilateral non-stenotic carotid plaques. However, non-stenotic carotid plaques with or without high-risk features often coexist with other potential etiologies of stroke, notably atrial fibrillation (8.5%), intracranial atherosclerosis (8.4%), patent foramen ovale (5-9%), and atrial cardiopathy (2.4%). Such puzzling clinical associations make it challenging to confirm the causal link between non-stenotic plaques and ESUS. There are several ongoing studies exploring whether select protein and RNA biomarkers of plaque progression or vulnerability could facilitate the reclassification of some ESUS as large vessel strokes or help to optimize secondary prevention strategies.

Lipoprotein(a): A Concealed Precursor of Increased Cardiovascular Risk? A Real-World Regional Lipid Clinic Experience

OBJECTIVE

Lipoprotein(a) [Lp(a)] is an independent cardiovascular risk factor. We present real-life characteristics of patients with increased Lp(a) levels attending a University Lipid Clinic.

METHODS

We retrospectively studied patients attending the University of Ioannina Hospital Lipid Clinic with Lp(a) levels ≥30 mg/dL who were followed-up for a median of 22 months.

RESULTS

One hundred eight patients (median age 59 years, 49% females) were included with median Lp(a) levels 67 mg/dL (30-320). Of patients, 25.1% had established atherosclerotic cardiovascular disease (ASCVD): 11.1 and 5.6% positive personal history of myocardial infarction (MI) and stroke, respectively, 6.5% carotid artery disease and 1.9% lower extremities arterial disease (LEAD). In addition, 35.2% of participants had heterozygous familial hypercholesterolemia (heFH), 37.9% positive family history of premature ASCVD, 29.6% hypertension, 12.0% diabetes and 5.5% chronic kidney disease (CKD). Of patients, 67.6% were receiving statin therapy and 16.6% additional ezetimibe at baseline visit, and 83 and 35% were receiving statin treatment and additional ezetimibe, respectively, during follow-up. Low-density cholesterol (LDL-C) levels and LDL-C_{corrected for Lp(a)} levels were significantly reduced in lipid-lowering therapy naive patients by 37 and 40% (p <0.05), in lipid-lowering therapy intensified patients by 31 and 36% (p <0.05), and in patients on stable lipid-lowering treatment by 15% (p <0.05) and 10% (p >0.05), respectively, during follow-up. Lp(a) levels increased by 9% (p <0.05).

CONCLUSION

Our data confirm the high prevalence of established ASCVD, hFH and positive familial history of premature ASCVD in patients with elevated Lp(a) levels. Lp(a) levels slightly increased during follow-up.

Lipoprotein(a) in atherosclerosis: from pathophysiology to clinical relevance and treatment options

Lipoprotein(a) (Lp(a)) was discovered more than 50 years ago, and a decade later, it was recognized as a risk factor for coronary artery disease. However, it has gained importance only in the past 10 years, with emergence of drugs that can effectively decrease its levels. Lp(a) is a low-density lipoprotein (LDL) with an added apolipoprotein(a) attached to the apolipoprotein B component via a disulphide bond. Circulating levels of Lp(a) are mainly genetically determined. Lp(a) has many functions, which include proatherosclerotic, prothrombotic and pro-inflammatory roles. Here, we review recent data on the role of Lp(a) in the atherosclerotic process, and treatment options for patients with cardiovascular diseases. Currently 'Proprotein convertase subtilisin/kexin type 9' (PCSK9) inhibitors that act through non-specific reduction of Lp(a) are the only drugs that have shown effectiveness in clinical trials, to provide reductions in cardiovascular morbidity and mortality. The effects of PCSK9 inhibitors are not purely through Lp(a) reduction, but also through LDL cholesterol reduction. Finally, we discuss new drugs on the horizon, and gene-based therapies that affect transcription and translation of apolipoprotein(a) mRNA. Clinical trials in patients with high Lp(a) and low LDL cholesterol might tell us whether Lp(a) lowering per se decreases cardiovascular morbidity and mortality.KEY MESSAGESLipoprotein(a) is an important risk factor in patients with cardiovascular diseases.Lipoprotein(a) has many functions, which include proatherosclerotic, prothrombotic and pro-inflammatory roles.Treatment options to lower lipoprotein(a) levels are currently scarce, but new drugs are on the horizon.

Progress and prospects of biological approaches targeting PCSK9 for cholesterol-lowering, from molecular mechanism to clinical efficacy

INTRODUCTION

Cardiovascular disorders are one of the leading causes of mortality and morbidity worldwide. Recent advances showed a promising role of proprotein convertase subtilisin/kexin type 9 (PCSK9) as a critical player in regulating plasma LDL levels and lipid metabolism.

AREAS COVERED

This review addresses the molecular functions of PCSK9 with a vision on the clinical progress of utilizing monoclonal antibodies and other biological approaches to block PCSK9 activity. The successful clinical trials with monoclonal antibodies are reviewed. Recent advances in (pre)clinical trials of other biological approaches, such as small interfering RNAs, are also discussed.

EXPERT OPINION

Discovery of PCSK9 and clinical use of its inhibitors to manage lipid metabolism is a step forward in hypolipidaemic therapy. A better understanding of the molecular activity of PCSK9 can help to identify new approaches in the inhibition of PCSK9 expression/activity. Whether if PCSK9 plays a role in other cardiometabolic conditions may provide grounds for further development of therapies.

Actual situation of lipoprotein apheresis in patients with elevated lipoprotein(a) levels

An elevation of lipoprotein(a) (Lp(a)) is an internationally recognized atherogenic risk factor, documented in epidemiological studies, in studies with Mendelian randomization and in genome-wide association studies (GWAS). At present, no drug is available to effectively reduce its concentration. In Germany, an elevation of Lp(a) associated with progressive cardiovascular diseases is officially recognized as an indication for a lipoprotein apheresis (LA). The number of patients who were treated with LA with this abnormality was steadily increasing in the years 2013-2016 - the official data are reported. In all new patients, who started to be treated at our LA center in 2017 (n = 20) the increased Lp(a) was a main indication for extracorporeal therapy, though some of them also showed clearly elevated LDL cholesterol (LDL-C) concentrations despite being treated with a maximal tolerated lipid-lowering drug therapy. A diabetes mellitus was seen in 5 patients. The higher was the Lp(a) level before the first LA session, the higher was the cardiovascular risk. Lp(a) concentrations measured before LA sessions were usually about 20% lower than those before the start of the LA therapy. Acutely, Lp(a) levels were reduced by about 70%. Following LA sessions the Lp(a) levels increased and in the majority reach pre-session concentrations after one week. Thus a weekly interval is best for the patients, but a few may need two sessions per week to stop the progress of atherosclerosis. The interval mean values were about 39% lower than previous levels. Several papers had been published showing a higher efficiency of LA therapy on the incidence of cardiovascular events in patients with high Lp(a) values when comparing with hypercholesterolemic patients with normal Lp(a) concentrations. Russian specific anti-Lp(a) columns positively affected coronary atherosclerosis. PCSK9 inhibitors reduce Lp(a) concentrations in many patients and in this way have a positive impact on cardiovascular outcomes. In the future, an antisense oligonucleotide against apolipoprotein(a) may be an alternative therapeutic option, provided a clear-cut reduction of cardiovascular events will be demonstrated.

PCSK9 inhibitors and cardiovascular outcomes

Introduction: Dyslipidemia, particularly elevated low-density lipoprotein cholesterol (LDL-C), is a key risk factor for atherosclerotic cardiovascular disease (ASCVD), and lipid-lowering drugs are beneficial for the primary and secondary prevention of cardiovascular (CV) disease. While statins are clear first-line drugs, new drug developments such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been shown to improve cardiovascular outcomes when added to statins. Evolocumab reduced the risk of cardiovascular events in patients with ASCVD when added to maximally tolerated statin therapy (± ezetimibe), and recent data from the ODYSSEY OUTCOMES trial indicate that alirocumab added to maximally tolerated statin therapy (± other lipid-lowering drugs) reduces the risk of cardiovascular events in patients with a recent acute coronary syndrome. In this article the authors review the available data on the effect of PCSK9 inhibitors on cardiovascular outcomes.Areas covered: This article reviews the available data on the effect of PCSK9 inhibitors on CV outcomes. Relevant papers were identified from a search of PubMed/Medline and the Cochrane Central Register of Controlled Trials (CENTRAL).Expert opinion: The authors conclude that PCSK9 inhibitors provide substantial and durable reductions in LDL-C levels and improve cardiovascular outcomes.

The prevalence and management of familial hypercholesterolemia in patients with acute coronary syndrome in the Polish tertiary centre: Results from the TERCET registry with 19,781 individuals

BACKGROUND AND AIMS

The prevalence of familial hypercholesterolemia (FH) is high among patients with stable coronary artery disease (CAD). However, data on FH on admission among patients with acute coronary syndrome (ACS) are still relatively scarce. Therefore, we aimed to assess the prevalence, lipid-lowering therapy and short- and long-term outcomes in patients with FH among ACS patients.

METHODS AND RESULTS

The investigation was performed in a cohort of 19,781 consecutive patients from the TERCET Registry. There were 7319 patients admitted with ACS: 3085 due to STEMI, 2256 due to NSTEMI, and 1978 due to UA. The stable CAD group (n = 12,462) was considered the reference group. Based on the personal and familial history of premature cardiovascular disease and LDL cholesterol concentration, the Dutch Lipid Clinic Network (DLCN) algorithm was used for FH diagnosis. The overall occurrence of probable/definite FH and possible FH was 1.2% and 13.5% respectively. Among patients with ACS, 1.6% had probable/definite FH and 17.0% possible FH. The highest occurrence of FH was observed in the STEMI subgroup (20.6%). Patients with definite and probable FH had higher 30-day mortality than patients without FH (8.2% and 3.8% vs. 2.0%, respectively; p = 0.0052). No significant differences were observed between the FH groups in the 12-, 36- and 60-month follow-up. Propensity-score matching analysis showed that definite/probable FH patients had significantly higher all-cause mortality at 36- and 60-month follow-up in comparison to non-FH subjects (11.4% vs. 4.8% and 19.2% vs. 7.2%, respectively; p ≤ 0.021 for both).

CONCLUSIONS

The prevalence of FH according to the DLCN criteria in the Polish very high-risk population is significantly higher in patients with ACS than in patients with sCAD. FH is a cause of increased all-cause mortality in the long-term follow-up.

Lipoprotein(a)-an interdisciplinary challenge

Lipoprotein(a) (Lp(a)) is an internationally recognized atherogenic risk factor which is inherited and not changed by nutrition or physical activity. At present, only proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors may modestly decrease its concentration (but not in all patients)-leading to a certain decrease in cardiovascular events (CVE) in controlled studies. However, at present an elevation of Lp(a) is not a generally accepted indication for their use. More effective is lipoprotein apheresis (LA) therapy with respect to both lowering Lp(a) levels and reduction of CVE. In the future, an antisense oligonucleotide against apolipoprotein(a) will probably be available. Atherosclerosis in patients with an elevation of Lp(a) may affect several vessel regions (carotids, aorta, coronaries, leg arteries). Thus, Lp(a) should be measured in high-risk patients. These patients are usually cared for by their family doctors and by other specialists who should closely cooperate. Lipidologists should decide whether costly therapies like PCSK9 inhibitors or LA should be started. The main aim of current therapy is to optimize all other risk factors (LDL cholesterol, hypertension, diabetes mellitus, body weight, renal insufficiency). Patients should be regularly monitored (lab data, heart, arteries). This paper describes the duties of physicians of different specialties when caring for patients with high Lp(a) concentrations.