Residual dyslipidemia according to low-density lipoprotein cholesterol, non–high-density lipoprotein cholesterol, and apolipoprotein B among statin-treated US adults: National Health and Nutrition Examination Survey 2009-2010

Apolipoprotein B: Bridging the Gap Between Evidence and Clinical Practice

Despite data suggesting that apolipoprotein B (apoB) measurement outperforms low-density lipoprotein cholesterol level measurement in predicting atherosclerotic cardiovascular disease risk, apoB measurement has not become widely adopted into routine clinical practice. One barrier for use of apoB measurement is lack of consistent guidance for clinicians on how to interpret and apply apoB results in clinical context. Whereas guidelines have often provided clear low-density lipoprotein cholesterol targets or triggers to initiate treatment change, consistent targets for apoB are lacking. In this review, we synthesize existing data regarding the epidemiology of apoB by comparing guideline recommendations regarding use of apoB measurement, describing population percentiles of apoB relative to low-density lipoprotein cholesterol levels, summarizing studies of discordance between low-density lipoprotein cholesterol and apoB levels, and evaluating apoB levels in clinical trials of lipid-lowering therapy to guide potential treatment targets. We propose evidence-guided apoB thresholds for use in cholesterol management and clinical care.

Geranylgeranyl isoprenoids and hepatic Rap1a regulate basal and statin-induced expression of PCSK9

LDL-C lowering is the main goal of atherosclerotic cardiovascular disease prevention, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition is now a validated therapeutic strategy that lowers serum LDL-C and reduces coronary events. Ironically, the most widely used medicine to lower cholesterol, statins, has been shown to increase circulating PCSK9 levels, which limits their efficacy. Here, we show that geranylgeranyl isoprenoids and hepatic Rap1a regulate both basal and statin-induced expression of PCSK9 and contribute to LDL-C homeostasis. Rap1a prenylation and activity is inhibited upon statin treatment, and statin-mediated PCSK9 induction is dependent on geranylgeranyl synthesis and hepatic Rap1a. Accordingly, treatment of mice with a small-molecule activator of Rap1a lowered PCSK9 protein and plasma cholesterol and inhibited statin-mediated PCSK9 induction in hepatocytes. The mechanism involves inhibition of the downstream RhoA-ROCK pathway and regulation of PCSK9 at the post-transcriptional level. These data further identify Rap1a as a novel regulator of PCSK9 protein and show that blocking Rap1a prenylation through lowering geranylgeranyl levels contributes to statin-mediated induction of PCSK9.

Geranylgeranyl Isoprenoids and Hepatic Rap1a Regulate Basal and Statin-Induced Expression of PCSK9

Low-density lipoprotein cholesterol (LDL-C) lowering is the main goal of atherosclerotic cardiovascular disease prevention, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition is now a validated therapeutic strategy that lowers serum LDL-C and reduces coronary events. Ironically, the most widely used medicine to lower cholesterol, statins, has been shown to increase circulating PCSK9 levels, which limits their efficacy. Here, we show that geranylgeranyl isoprenoids and hepatic Rap1a regulate both basal and statin induced expression of PCSK9 and contribute to LDL-C homeostasis. Rap1a prenylation and activity is inhibited upon statin treatment, and statin mediated PCSK9 induction is dependent on geranylgeranyl synthesis and hepatic Rap1a. Accordingly, treatment of mice with a small molecule activator of Rap1a lowered PCSK9 protein and plasma cholesterol and inhibited statin mediated PCSK9 induction in hepatocytes. The mechanism involves inhibition of the downstream RhoA-ROCK pathway and regulation of PCSK9 at the post transcriptional level. These data further identify Rap1a as a novel regulator of PCSK9 protein and show that blocking Rap1a prenylation through lowering geranylgeranyl levels contributes to statin-mediated induction of PCSK9.

Effects of natural dihydrochalcones in sweet tea (Lithocarpus polystachyus) on diabetes: a systematical review and meta-analysis of animal studies

Sweet tea (Lithocarpus polystachyus Rehd.), a natural functional food highly rich in dihydrochalcones including trilobatin, phlorizin and phloretin, is reported to possess numerous biological activities especially for treating diabetes. Here, the aim of this systematical review and meta-analysis is to assess the effect of dihydrochalcones in sweet tea (DST) on diabetes and summarize their possible mechanisms. We searched in eight databases including Embase, PubMed, Cochrane, Web of Science, WanFang database, VIP database, China National Knowledge Infrastructure and China Biology Medicine from Jan 2000 to Nov 2021 and ultimately included 21 animal studies in this review. A total of 10 outcome measurements including blood lipid indexes, blood glucose, insulin resistance indicators and oxidative stress biomarkers were extracted for meta-analysis using RevMan 5.4 software. DST significantly decreased the levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), blood glucose (BG), homeostasis model assessment of insulin resistance (HOMA-IR) and malondialdehyde (MDA), and increased high-density lipoprotein cholesterol (HDL-c), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in diabetic animal models. In summary, DST could treat diabetes by regulation of blood glucose/lipid metabolism, oxidative/carbonyl stress, inflammatory response etc.

Residual Risk of Coronary Atherosclerotic Heart Disease and Severity of Coronary Atherosclerosis Assessed by ApoB and LDL-C in Participants With Statin Treatment: A Retrospective Cohort Study

BACKGROUND

Low-density lipoprotein cholesterol (LDL-C) is the primary target of lipid-lowering therapy on the management of hypercholesterolemia in the United States and European guidelines, while apolipoprotein B (apoB) is the secondary target. The objective was to determine if elevated levels of apoB is superior to LDL-C in assessing residual risk of coronary atherosclerotic heart disease and severity of coronary atherosclerosis in participants with statin treatment.

METHODS

This study included 131 participants with statin treatment. The generalized linear model and relative risk regression (generalized linear Poisson model with robust error variance) were used to analyze the association of the levels of apoB and LDL-C with the severity of coronary atherosclerosis and residual risk of coronary atherosclerotic heart disease.

RESULTS

Categorizing apoB and LDL-C based on tertiles, higher levels of apoB were significantly associated with the severity of coronary atherosclerosis (P_trend = 0.012), whereas no such associations were found for elevated levels of LDL-C (P_trend = 0.585). After multivariate adjustment, higher levels of apoB were significantly associated with residual risk of coronary atherosclerotic heart disease. When compared with low-level apoB (≤0.66 g/L), the multivariate adjusted RR and 95% CI of intermediate-level apoB (0.67-0.89 g/L) and high-level apoB (≥0.90 g/L) were 1.16 (1.01, 1.33) and 1.31 (1.08, 1.60), respectively (P_trend = 0.011). There was a 45% increased residual risk of coronary atherosclerotic heart disease per unit increment in natural log-transformed apoB (P_trend <0.05). However, higher levels of LDL-C were not significantly associated with residual risk of coronary atherosclerotic heart disease. When compared with low-level LDL-C (≤1.56 mmol/L), the multivariate adjusted RR and 95% CI of intermediate-level LDL-C (1.57-2.30 mmol/L) and high-level LDL-C (≥2.31 mmol/L) were 0.99 (0.84, 1.15) and 1.10 (0.86, 1.42), respectively (P_trend = 0.437). Similar results were observed in the stratified analyses and sensitivity analyses. No significant interactions were detected for both apoB and LDL-C (all P_interaction>0.05).

CONCLUSIONS

Elevated apoB are superior in assessing the residual risk of coronary atherosclerotic heart disease and severity of coronary atherosclerosis in participants with statin treatment.

Quantifying atherogenic lipoproteins for lipid-lowering strategies: consensus-based recommendations from EAS and EFLM

The joint consensus panel of the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently addressed present and future challenges in the laboratory diagnostics of atherogenic lipoproteins. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC), LDL cholesterol (LDLC), and calculated non-HDLC (=total - HDLC) constitute the primary lipid panel for estimating risk of atherosclerotic cardiovascular disease (ASCVD) and can be measured in the nonfasting state. LDLC is the primary target of lipid-lowering therapies. For on-treatment follow-up, LDLC shall be measured or calculated by the same method to attenuate errors in treatment decisions due to marked between-method variations. Lipoprotein(a) [Lp(a)]-cholesterol is part of measured or calculated LDLC and should be estimated at least once in all patients at risk of ASCVD, especially in those whose LDLC declines poorly upon statin treatment. Residual risk of ASCVD even under optimal LDL-lowering treatment should be also assessed by non-HDLC or apolipoprotein B (apoB), especially in patients with mild-to-moderate hypertriglyceridemia (2-10 mmol/L). Non-HDLC includes the assessment of remnant lipoprotein cholesterol and shall be reported in all standard lipid panels. Additional apoB measurement can detect elevated LDL particle (LDLP) numbers often unidentified on the basis of LDLC alone. Reference intervals of lipids, lipoproteins, and apolipoproteins are reported for European men and women aged 20-100 years. However, laboratories shall flag abnormal lipid values with reference to therapeutic decision thresholds.

Non-HDL Cholesterol or apoB: Which to Prefer as a Target for the Prevention of Atherosclerotic Cardiovascular Disease?

PURPOSE OF REVIEW

Guidelines propose using non-HDL cholesterol or apolipoprotein (apo) B as a secondary treatment target to reduce residual cardiovascular risk of LDL-targeted therapies. This review summarizes the strengths, weaknesses, opportunities, and threats (SWOT) of using apoB compared with non-HDL cholesterol.

RECENT FINDINGS

Non-HDL cholesterol, calculated as total-HDL cholesterol, includes the assessment of remnant lipoprotein cholesterol, an additional risk factor independent of LDL cholesterol. ApoB is a direct measure of circulating numbers of atherogenic lipoproteins, and its measurement can be standardized across laboratories worldwide. Discordance analysis of non-HDL cholesterol versus apoB demonstrates that apoB is the more accurate marker of cardiovascular risk. Baseline and on-treatment apoB can identify elevated numbers of small cholesterol-depleted LDL particles that are not reflected by LDL and non-HDL cholesterol. ApoB is superior to non-HDL cholesterol as a secondary target in patients with mild-to-moderate hypertriglyceridemia (175-880 mg/dL), diabetes, obesity or metabolic syndrome, or very low LDL cholesterol < 70 mg/dL. When apoB is not available, non-HDL cholesterol should be used to supplement LDLC.

Demographic And Clinical Characteristics Of Patients Prescribed Proprotein Convertase Subtilisin/kexin Type 9 Inhibitor Therapy And Patients Whose Current Lipid-Lowering Therapy Was Modified

Purpose

Our objective was to describe the demographic and clinical characteristics of real-world patients in the US with elevated low-density lipoprotein cholesterol (LDL-C) whose lipid-lowering therapy (LLT) ─ both proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor and non-PCSK9 inhibitor ─ was actively modified.

Methods

This retrospective cohort study used linked laboratory (Prognos), pharmacy (IMS Formulary Impact Analyzer), and medical claims (IQVIA Dx/LRx or PharMetrics Plus) data. PCSK9 inhibitor–prescribed patients with LDL-C ≥70 mg/dL (multiply by 0.02586 for mmol/L) at the time of prescription were matched by LDL-C test date to patients whose non-PCSK9 inhibitor therapy was modified by intensifying statin therapy, switching statins without intensification, or augmenting with ezetimibe (N=12,345 in each cohort). Baseline demographics, use of LLT, LDL-C values, atherosclerotic cardiovascular disease (ASCVD) diagnoses and cardiovascular comorbidities, and occurrence of major adverse cardiovascular events (MACE) were assessed during the 2-year pre-index period.

Results

Mean age was 66.2 years in the PCSK9 inhibitor cohort and 64.1 years in the cohort whose LLT regimen was otherwise modified. Respectively, mean baseline LDL-C values were 150 and 121 mg/dL; 60.3% and 39.0% of patients had ASCVD diagnoses, and 9.6% and 5.1% had experienced a recent MACE. Prevalence of ASCVD diagnoses in the PCSK9 inhibitor and modified non-PCSK9 inhibitor cohorts, respectively, was 15.5% vs 9.1% for acute coronary syndrome, 20.7% vs 8.7% for coronary revascularization, and 22.2% vs 5.1% for possible familial hypercholesterolemia. In addition, 19.8% of patients in the PCSK9 inhibitor cohort were receiving both statins and ezetimibe vs 5.0% in the modified LLT cohort.

Conclusion

Physicians are prescribing PCSK9 inhibitor therapy to patients with markedly elevated LDL-C levels who also have comorbid risk factors for adverse cardiovascular events. These results may be of interest to payers and policymakers involved in devising access strategies for PCSK9 inhibitors.

Targeting the peptidase PCSK9 to reduce cardiovascular risk: Implications for basic science and upcoming challenges

LDL cholesterol (LDL-C) plays a central role in the progression of atherosclerosis. Statin therapy for lowering LDL-C reduces the risk of atherosclerotic cardiovascular disease and is the recommended first-line treatment for patients with high LDL-C levels. However, some patients are unable to achieve an adequate reduction in LDL-C with statins or are statin-intolerant; thus, PCSK9 inhibitors were developed to reduce LDL-C levels, instead of statin therapy. PCSK9 monoclonal antibodies dramatically reduce LDL-C levels and cardiovascular risk, and promising new PCSK9 inhibitors using different mechanisms are currently being developed. The absolute benefit of LDL-C reduction depends on the individual absolute risk and the achieved absolute reduction in LDL-C. Therefore, PCSK9 inhibitors may provide the greatest benefits from further LDL-C reduction for the highest risk patients. Here, we focus on PCSK9-targeted therapies and discuss the challenges of LDL-C reduction for prevention of atherosclerotic cardiovascular disease.

Current pharmacotherapeutic options for primary dyslipidemia in adults

INTRODUCTION

Atherosclerotic cardiovascular disease (ASCVD) and its clinical manifestations, remain a leading cause of death and disability worldwide. One of the major risk factors of ASCVD is dyslipidemia and all the available guidelines suggest the importance of strategies for lipid control in a remarkable proportion of the general population.

AREAS COVERED

This review focuses on the therapeutic options available for the management of lipid disorders in adults.

EXPERT OPINION

A large body of evidence supports that statins are still the first-line option for the management of hypercholesterolemia in a large percentage of patients. Statins should be given at the appropriate dose and considering the differences in lipid-lowering potency across the different medications. The main current challenge in the treatment of lipid disorders is the need of improving patient adherence and persistence to lipid-lowering treatments beyond the drug choice and the target lipid component. To achieve this goal, the best strategy would be to treat the patients by using the appropriate drugs given at adequate doses to reach the treatment target. We should also avoid drug interactions, monitor possible untoward side effects and promote adherence to treatment by tailoring treatment strategies to each patient.

Quantifying Unmet Need in Statin-Treated Hyperlipidemia Patients and the Potential Benefit of Further LDL-C Reduction Through an EHR-Based Retrospective Cohort Study

BACKGROUND

Statins are effective in helping prevent cardiovascular disease (CVD). However, studies suggest that only 20%-64% of patients taking statins achieve reasonable low-density lipoprotein cholesterol (LDL-C) thresholds. On-treatment levels of LDL-C remain a key predictor of residual CVD event risk.

OBJECTIVES

To (a) determine how many patients on statins achieved the therapeutic threshold of LDL-C < 100 mg per dL (general cohort) and < 70 mg per dL (secondary prevention cohort, or subcohort, with preexisting CVD); (b) estimate the number of potentially avoidable CVD events if the threshold were reached; and (c) forecast potential cost savings.

METHODS

A retrospective, longitudinal cohort study using electronic health record data from the Indiana Network for Patient Care (INPC) was conducted. The INPC provides comprehensive information about patients in Indiana across health care organizations and care settings. Patients were aged > 45 years and seen between January 1, 2012, and October 31, 2016 (ensuring study of contemporary practice), were statin-naive for 12 months before the index date of initiating statin therapy, and had an LDL-C value recorded 6-18 months after the index date. Subsequent to descriptive cohort analysis, the theoretical CVD risk reduction achievable by reaching the threshold was calculated using Framingham Risk Score and Cholesterol Treatment Trialists' Collaboration formulas. Estimated potential cost savings used published first-year costs of CVD events, adjusted for inflation and discounted to the present day.

RESULTS

Of the 89,267 patients initiating statins, 30,083 (33.7%) did not achieve the LDL-C threshold (subcohort: 58.1%). In both groups, not achieving the threshold was associated with patients who were female, black, and those who had reduced medication adherence. Higher levels of preventive aspirin use and antihypertensive treatment were associated with threshold achievement. In both cohorts, approximately 64% of patients above the threshold were within 30 mg per dL of the respective threshold. Adherence to statin therapy regimen, judged by a medication possession ratio of ≥ 80%, was 57.4% in the general cohort and 56.7% in the subcohort. Of the patients who adhered to therapy, 23.7% of the general cohort and 50.5% of the subcohort had LDL-C levels that did not meet the threshold. 10-year CVD event risk in the at-or-above threshold group was 22.78% (SD = 17.24%) in the general cohort and 29.56% (SD = 18.19%) in the subcohort. By reducing LDL-C to the threshold, a potential relative risk reduction of 14.8% in the general cohort could avoid 1,173 CVD events over 10 years (subcohort: 15.7% and 454 events). Given first-year inpatient and follow-up costs of $37,300 per CVD event, this risk reduction could save about $1,455 per patient treated to reach the threshold (subcohort: $1,902; 2017 U.S. dollars) over a 10-year period.

CONCLUSIONS

Across multiple health care systems in Indiana, between 34% (general cohort) and 58% (secondary prevention cohort) of patients treated with statins did not achieve therapeutic LDL-C thresholds. Based on current CVD event risk and cost projections, such patients seem to be at increased risk and may represent an important and potentially preventable burden on health care costs.

DISCLOSURES

Funding support for this study was provided by Merck (Kenilworth, NJ). Chase and Boggs are employed by Merck. Simpson is a consultant to Merck and Pfizer. The other authors have nothing to disclose.

Non-antibody Approaches to Proprotein Convertase Subtilisin Kexin 9 Inhibition: siRNA, Antisense Oligonucleotides, Adnectins, Vaccination, and New Attempts at Small-Molecule Inhibitors Based on New Discoveries

Low-density lipoprotein (LDL) is one of the principal risk factors for atherosclerosis. Circulating LDL particles can penetrate into the sub-endothelial space of arterial walls. These particles undergo oxidation and promote an inflammatory response, resulting in injury to the vascular endothelial wall. Persistent elevation of LDL-cholesterol (LDL-C) is linked to the progression of fatty streaks to lipid-rich plaque and thus atherosclerosis. LDL-C is a causal factor for atherosclerotic cardiovascular disease and lowering it is beneficial across a range of conditions associated with high risk of cardiovascular events. Therefore, all guidelines-recommended initiations of statin therapy for patients at high cardiovascular risk is irrespective of LDL-C. In addition, intensive LDL-C lowering therapy with statins has been demonstrated to result in a greater reduction of cardiovascular event risk in large clinical trials. However, many high-risk patients receiving statins fail to achieve the guideline-recommended reduction in LDL-C levels in routine clinical practice. Moreover, low levels of adherence and often high rates of discontinuation demand the need for further therapies. Ezetimibe has typically been used as a complement to statins when further LDL-C reduction is required. More recently, proprotein convertase subtilisin kexin 9 (PCSK9) has emerged as a novel therapeutic target for lowering LDL-C levels, with PCSK9 inhibitors offering greater reductions than feasible through the addition of ezetimibe. PCSK9 monoclonal antibodies have been shown to not only considerably lower LDL-C levels but also cardiovascular events. However, PCSK9 monoclonal antibodies require once- or twice-monthly subcutaneous injections. Further, their manufacturing process is expensive, increasing the cost of therapy. Therefore, several non-antibody treatments to inhibit PCSK9 function are being developed as alternative approaches to monoclonal antibodies. These include gene-silencing or editing technologies, such as antisense oligonucleotides, small interfering RNA, and the clustered regularly interspaced short palindromic repeats/Cas9 platform; small-molecule inhibitors; mimetic peptides; adnectins; and vaccination. In this review, we summarize the current knowledge base on the role of PCSK9 in lipid metabolism and an overview of non-antibody approaches for PCSK9 inhibition and their limitations. The subsequent development of alternative approaches to PCSK9 inhibition may give us more affordable and convenient therapeutic options for the management of high-risk patients.

Diabetic Dyslipidemia: Epidemiology and Prevention of Cardiovascular Disease and Implications of Newer Therapies

PURPOSE OF REVIEW

Dyslipidemia in patients with T2DM confers significant additional risk of adverse outcomes to patients with cardiovascular disease (CVD). These patients carry residual risk of adverse outcomes despite optimal management with conventional therapy such as lifestyle changes and statin therapy. The role of both nonstatin monotherapy in statin-intolerant patients and combination therapy with statins in patients with high risk of CVD events has been well studied. We sought to review the role of newer therapies in risk reduction in these patients.

RECENT FINDINGS

Traditionally, non-statin options have included medications such as niacin, ezetimibe, fenofibrate, and n-3 fatty acids. Recently, drugs such as ezetimibe, inclisiran, and PCSK9 inhibitors have been studied with favorable results without an increased risk of developing new-onset diabetes. These medications hold the promise of increasing options to reduce cardiovascular risk in patients with T2DM. The role of newer non-statin therapies in patients with diabetic dyslipidemia in combination with statins needs to be further explored.

Which Lipids Should Be Analyzed for Diagnostic Workup and Follow-up of Patients with Hyperlipidemias?

PURPOSE OF REVIEW

To summarize and discuss the clinical use of lipid and apolipoprotein tests in the settings of diagnosis and therapeutic follow-up of hyperlipidemia.

RECENT FINDINGS

The joint consensus panel of the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently produced recommendations on the measurement of atherogenic lipoproteins, taking into account the strengths and weaknesses of analytical and clinical performances of the tests. Total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and calculated non-HDL cholesterol (= LDL + remnant cholesterol) constitute the primary lipid panel for hyperlipidemia diagnosis and cardiovascular risk estimation. LDL cholesterol is the primary target of lipid-lowering therapies. Non-HDL cholesterol or apolipoprotein B should be used as secondary therapeutic target in patients with mild-to-moderate hypertriglyceridemia, 2-10 mmol/l (175-880 mg/dl). Lipoprotein (a) is included in LDL cholesterol and should be measured at least once in all patients at cardiovascular risk, including to explain poor response to statin treatment.

Quantifying Atherogenic Lipoproteins: Current and Future Challenges in the Era of Personalized Medicine and Very Low Concentrations of LDL Cholesterol. A Consensus Statement from EAS and EFLM

BACKGROUND

The European Atherosclerosis Society-European Federation of Clinical Chemistry and Laboratory Medicine Consensus Panel aims to provide recommendations to optimize atherogenic lipoprotein quantification for cardiovascular risk management.

CONTENT

We critically examined LDL cholesterol, non-HDL cholesterol, apolipoprotein B (apoB), and LDL particle number assays based on key criteria for medical application of biomarkers. (a) Analytical performance: Discordant LDL cholesterol quantification occurs when LDL cholesterol is measured or calculated with different assays, especially in patients with hypertriglyceridemia >175 mg/dL (2 mmol/L) and low LDL cholesterol concentrations <70 mg/dL (1.8 mmol/L). Increased lipoprotein(a) should be excluded in patients not achieving LDL cholesterol goals with treatment. Non-HDL cholesterol includes the atherogenic risk component of remnant cholesterol and can be calculated in a standard nonfasting lipid panel without additional expense. ApoB more accurately reflects LDL particle number. (b) Clinical performance: LDL cholesterol, non-HDL cholesterol, and apoB are comparable predictors of cardiovascular events in prospective population studies and clinical trials; however, discordance analysis of the markers improves risk prediction by adding remnant cholesterol (included in non-HDL cholesterol) and LDL particle number (with apoB) risk components to LDL cholesterol testing. (c) Clinical and cost-effectiveness: There is no consistent evidence yet that non-HDL cholesterol-, apoB-, or LDL particle-targeted treatment reduces the number of cardiovascular events and healthcare-related costs than treatment targeted to LDL cholesterol.

SUMMARY

Follow-up of pre- and on-treatment (measured or calculated) LDL cholesterol concentration in a patient should ideally be performed with the same documented test method. Non-HDL cholesterol (or apoB) should be the secondary treatment target in patients with mild to moderate hypertriglyceridemia, in whom LDL cholesterol measurement or calculation is less accurate and often less predictive of cardiovascular risk. Laboratories should report non-HDL cholesterol in all standard lipid panels.

Discordance between lipoprotein particle number and cholesterol content: an update

PURPOSE OF REVIEW

The cholesterol content within atherogenic apolipoprotein-B (apoB) containing lipid particles is the center of consensus guidelines and clinicians' focus whenever evaluating a patient's risk for atherosclerotic cardiovascular disease. The pathobiology of atherosclerosis requires the retention of lipoprotein particles within the vascular intima over time followed by maladaptive inflammation resulting in plaque formation and rupture in some. The cholesterol content is widely variable within each particle creating either cholesterol-deplete or cholesterol-enriched particles. This variance in particle cholesterol content varies within and between individuals. Discordance analysis exploits this difference in cholesterol content of particles to demonstrate the differential significance of LDL-cholesterol (LDL-C) and non-HDL-C from measures of lipoprotein particle number in terms of assessing atherosclerotic cardiovascular disease risks.

RECENT FINDINGS

Three studies have added to the growing body of literature of discordance analysis. Despite wide variability of discordance cutoffs, baseline risk of atherosclerotic disease, and populations sampled, the conclusion remains the same: risk of atherosclerotic disease follows apoB lipid particle concentration rather than cholesterol content of lipid particles.

SUMMARY

In addition to traditional lipid fractions, assessments of atherogenic particle number should be strongly considered whenever assessing CVD risk in nontreated and treated individuals. There is a need for clinical trials that focus not only on the reduction in LDL-C but apoB, as well.

Relationship Between Adiponectin and apoB in Individuals With Diabetes in the Atlantic PATH Cohort

Context

The increasing prevalence of obesity and diabetes greatly influences the risk for cardiovascular (CV) comorbidities and affects the quality of life of many people. However, the relationship among diabetes, obesity, and cardiovascular risk is complex and requires further investigation to understand the biological milieu connecting these conditions.

Objective

The aim of the current study was to explore the relationship between biological markers of adipose tissue function (adiponectin) and CV risk (apolipoprotein B) in body mass index (BMI)-matched participants with and without diabetes.

Design

Nested case-control study.

Setting

The Atlantic Partnership for Tomorrow's Health (PATH) cohort represents four Atlantic Canadian provinces: Newfoundland and Labrador, New Brunswick; Nova Scotia; and Prince Edward Island.

Participants

The study population (n = 480) was aged 35 to 69 years, 240 with diabetes and 240 without diabetes.

Main Outcome Measures

Groups with and without diabetes were matched for sex and BMI. Both measured and self-reported data were used to examine disease status, adiposity, and lifestyle factors. Immunoassays were used to measure plasma markers.

Results

In these participants, plasma adiponectin levels were lower among those with diabetes than those without diabetes; these results were sex-specific, with a strong relationship seen in women. In contrast, in participants matched for sex and adiposity, plasma apoB levels were similar between participants with and those without diabetes.

Conclusion

Measures of adiposity were higher in participants with diabetes. However, when matched for adiposity, the adipokine adiponectin exhibited a strong inverse association with diabetes.

Efficacy and safety of alirocumab in insulin-treated individuals with type 1 or type 2 diabetes and high cardiovascular risk: The ODYSSEY DM-INSULIN randomized trial

AIMS

To investigate the efficacy and safety of alirocumab in participants with type 2 (T2D) or type 1 diabetes (T1D) treated with insulin who have elevated LDL cholesterol levels despite maximally tolerated statin therapy.

METHODS

Participants at high cardiovascular risk with T2D (n = 441) or T1D (n = 76) and LDL cholesterol levels ≥1.8 mmol/L (≥70 mg/dL) were randomized 2:1 to alirocumab:placebo administered subcutaneously every 2 weeks, for 24 weeks' double-blind treatment. Alirocumab-treated participants received 75 mg every 2 weeks, with blinded dose increase to 150 mg every 2 weeks at week 12 if week 8 LDL cholesterol levels were ≥1.8 mmol/L. Primary endpoints were percentage change in calculated LDL cholesterol from baseline to week 24, and safety assessments.

RESULTS

Alirocumab reduced LDL cholesterol from baseline to week 24 by a mean ± standard error of 49.0% ± 2.7% and 47.8% ± 6.5% vs placebo (both P < .0001) in participants with T2D and T1D, respectively. Significant reductions were observed in non-HDL cholesterol (P < .0001), apolipoprotein B (P < .0001) and lipoprotein (a) (P ≤ .0039). At week 24, 76.4% and 70.2% of the alirocumab group achieved LDL cholesterol <1.8 mmol/L in the T2D and T1D populations (P < .0001), respectively. Glycated haemoglobin and fasting plasma glucose levels remained stable for the study duration. Treatment-emergent adverse events were observed in 64.5% of alirocumab- vs 64.1% of placebo-treated individuals (overall population).

CONCLUSIONS

Alirocumab produced significant LDL cholesterol reductions in participants with insulin-treated diabetes regardless of diabetes type, and was generally well tolerated. Concomitant administration of alirocumab and insulin did not raise any safety concerns (NCT02585778).

PCSK9 Inhibitors: Mechanisms of Action, Metabolic Effects, and Clinical Outcomes

Atherosclerotic cardiovascular disease (ASCVD) is associated with significant morbidity and mortality worldwide. Increased serum levels of low-density lipoprotein cholesterol (LDL-C) are an independent risk factor for ASCVD, and clinical trial data have shown that lowering LDL-C generally reduces cardiovascular risk. Until recently, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) have been the main therapy for lowering LDL-C. However, some statin-treated patients have persistently elevated residual cardiovascular risk due to inadequate lowering of LDL-C levels or non-LDL-related dyslipidemia. In addition, adverse effects of statins may limit their tolerability and therefore the ability to attain effective doses in some patients. A new class of drugs that inhibit proprotein convertase subtilisin-kexin type 9 (PCSK9) has been developed to treat hyperlipidemia. This review discusses the history and mechanism of action of PCSK9 inhibitors, their metabolic effects, and clinical outcomes associated with these medications, highlighting recent large cardiovascular outcome trials investigating these therapies.

Bempedoic Acid (ETC-1002): an Investigational Inhibitor of ATP Citrate Lyase

Bempedoic acid (ETC-1002), a novel therapeutic approach for low-density lipoprotein cholesterol (LDL-C) lowering, inhibits ATP citrate lyase (ACL), an enzyme involved in fatty acid and cholesterol synthesis. Although rodent studies suggested potential effects of ACL inhibition on both fatty acid and cholesterol synthesis, studies in humans show an effect only on cholesterol synthesis. In phase 2 studies, ETC-1002 reduced LDL-C as monotherapy, combined with ezetimibe, and added to statin therapy, with LDL-C lowering most pronounced when ETC-1002 was combined with ezetimibe in patients who cannot tolerate statins. Whether clinically relevant favorable effects on other cardiometabolic risk factors such as hyperglycemia and insulin resistance occur in humans is unknown and requires further investigation. Promising phase 2 results have led to the design of a large phase 3 program to gain more information on efficacy and safety of ETC-1002 in combination with statins and when added to ezetimibe in statin-intolerant patients.

Residual atherosclerotic cardiovascular disease risk in statin-treated adults: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Residual atherosclerotic cardiovascular disease (ASCVD) risk in statin-treated US adults without known ASCVD is not well described.

OBJECTIVE

To quantitate residual ASCVD risk and its predictors in statin-treated adults.

METHODS

We studied 1014 statin-treated adults (53.3% female, mean 66.0 years) free of clinical ASCVD in the Multi-Ethnic Study of Atherosclerosis. We examined ASCVD event rates by National Lipid Association risk groups over 11-year follow-up and the relation of standard risk factors, biomarkers, and subclinical atherosclerosis measures with residual ASCVD event risk.

RESULTS

Overall, 5.3% of participants were at low, 12.2% at moderate, 60.3% at high, and 22.2% at very high baseline risk. Despite statin therapy, age- and race-standardized ASCVD rates per 1000 person-years for men and women were both 4.9 for low/moderate risk, 19.1 and 14.2 for high risk, and 35.6 and 26.7 for very high risk, respectively. Specific independent predictors of residual risk included current smoking, family history, diabetes, high-sensitivity C-reactive protein, low-density lipoprotein particle number, carotid intimal medial thickness, and especially coronary artery calcium score. Those on moderate- or high-intensity statins at baseline (compared with low intensity) had 39% lower risks and those who increased statin intensity 62% lower ASCVD event risks (P < .01).

CONCLUSION

Residual risk of ASCVD remains high despite statin treatment and is predicted by specific risk factors and subclinical atherosclerosis. These findings may be helpful for identifying those at highest risk needing more aggressive treatment.

Design and rationale of the ODYSSEY DM-DYSLIPIDEMIA trial: lipid-lowering efficacy and safety of alirocumab in individuals with type 2 diabetes and mixed dyslipidaemia at high cardiovascular risk

Background

Type 2 diabetes mellitus (T2DM) is often associated with mixed dyslipidaemia, where non-high-density lipoprotein cholesterol (non-HDL-C) levels may more closely align with cardiovascular risk than low-density lipoprotein cholesterol (LDL-C). We describe the design and rationale of the ODYSSEY DM-DYSLIPIDEMIA study that assesses the efficacy and safety of alirocumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, versus lipid-lowering usual care in individuals with T2DM and mixed dyslipidaemia at high cardiovascular risk with non-HDL-C inadequately controlled despite maximally tolerated statin therapy. For the first time, atherogenic cholesterol-lowering with a PCSK9 inhibitor will be assessed with non-HDL-C as the primary endpoint with usual care as the comparator.

Methods

DM-DYSLIPIDEMIA is a Phase 3b/4, randomised, open-label, parallel group, multinational study that planned to enrol 420 individuals. Main inclusion criteria were T2DM and mixed dyslipidaemia (non-HDL-C ≥100 mg/dl [≥2.59 mmol/l], and triglycerides ≥150 and <500 mg/dl [≥1.70 and <5.65 mmol/l]) with documented atherosclerotic cardiovascular disease or ≥1 additional cardiovascular risk factor. Participants were randomised (2:1) to alirocumab 75 mg every 2 weeks (Q2W) or lipid-lowering usual care on top of maximally tolerated statin (or no statin if intolerant). If randomised to usual care, investigators were able to add their pre-specified choice of one of the following to the patient’s current statin regimen: ezetimibe, fenofibrate, omega-3 fatty acids or nicotinic acid, in accordance with local standard-of-care. Alirocumab-treated individuals with non-HDL-C ≥100 mg/dl at week 8 will undergo a blinded dose increase to 150 mg Q2W at week 12. The primary efficacy endpoint is non-HDL-C change from baseline to week 24 with alirocumab versus usual care; other lipid levels (including LDL-C), glycaemia-related measures, safety and tolerability will also be assessed. Alirocumab will be compared to fenofibrate in a secondary analysis.

Results

Recruitment completed with 413 individuals randomised in 14 countries worldwide. Results of this trial are expected in the second quarter of 2017.

Conclusions

ODYSSEY DM-DYSLIPIDEMIA will provide information on the efficacy and safety of alirocumab versus lipid-lowering usual care in individuals with T2DM and mixed dyslipidaemia at high cardiovascular risk using non-HDL-C as the primary efficacy endpoint.

Trial registration NCT02642159 (registered December 24, 2015)

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0552-4) contains supplementary material, which is available to authorized users.

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.

Efficacy and safety of alirocumab in insulin-treated patients with type 1 or type 2 diabetes and high cardiovascular risk: Rationale and design of the ODYSSEY DM-INSULIN trial

AIMS

The coadministration of alirocumab, a PCSK9 inhibitor for treatment of hypercholesterolaemia, and insulin in diabetes mellitus (DM) requires further study. Described here is the rationale behind a phase-IIIb study designed to characterize the efficacy and safety of alirocumab in insulin-treated patients with type 1 (T1) or type 2 (T2) DM with hypercholesterolaemia and high cardiovascular (CV) risk.

METHODS

ODYSSEY DM-INSULIN (NCT02585778) is a randomized, double-blind, placebo-controlled, multicentre study that planned to enrol around 400 T2 and up to 100 T1 insulin-treated DM patients. Participants had low-density lipoprotein cholesterol (LDL-C) levels at screening≥70mg/dL (1.81mmol/L) with stable maximum tolerated statin therapy or were statin-intolerant, and taking (or not) other lipid-lowering therapy; they also had established CV disease or at least one additional CV risk factor. Eligible patients were randomized 2:1 to 24weeks of alirocumab 75mg every 2weeks (Q2W) or a placebo. Alirocumab-treated patients with LDL-C≥70mg/dL at week 8 underwent a blinded dose increase to 150mg Q2W at week 12. Primary endpoints were the difference between treatment arms in percentage change of calculated LDL-C from baseline to week 24, and alirocumab safety.

RESULTS

This is an ongoing clinical trial, with 76 T1 and 441 T2 DM patients enrolled; results are expected in mid-2017.

CONCLUSION

The ODYSSEY DM-INSULIN study will provide information on the efficacy and safety of alirocumab in insulin-treated individuals with T1 or T2 DM who are at high CV risk and have hypercholesterolaemia not adequately controlled by the maximum tolerated statin therapy.

Should apolipoprotein B replace LDL cholesterol as therapeutic targets are lowered?

PURPOSE OF REVIEW

The success of LDL cholesterol (LDL-C) as a predictor of atherosclerotic cardiovascular disease and a therapeutic target is indisputable. Apolipoprotein B (apoB) is a more contemporary and physiologically relevant measure of atherogenic lipoproteins. This report summarizes recent comparisons of apoB and LDL-C as biomarkers of cardiovascular risk.

RECENT FINDINGS

Multiple recent reports have found that LDL-C methods perform poorly at low concentrations (<70 mg/dl). Several meta-analyses from randomized controlled trials and large prospective observational studies have found that apoB and LDL-C provide equivalent information on risk of cardiovascular disease. More innovative analyses have asserted that apoB is a superior indicator of actual risk when apoB and LDL-C disagree.

SUMMARY

ApoB is more analytically robust and standardized biomarker than LDL-C. Large population studies have found that apoB is at worst clinically equivalent to LDL-C and likely superior when disagreement exists. Realistically, many obstacles prevent the wide spread adoption of apoB and for now providers and their patients must weigh the costs and benefits of apoB.

Residual Dyslipidemia Leads to Unfavorable Outcomes in Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention

Background. The present study aimed to evaluate the prevalence and prognosis of residual lipid abnormalities in statin-treated acute coronary syndrome (ACS) patients after percutaneous coronary intervention (PCI). Subjects and Methods. A total of 3,047 ACS patients who underwent PCI and received statin therapy were included. Plasma concentrations of LDL-C, HDL-C, and TG were measured. For the follow-up study, major adverse cardiovascular cerebrovascular events (MACCE; including total death, cardiovascular death, myocardial infarction, and revascularization) were documented. Results. A total of 93.14% of all individuals were followed up for 18.1 months (range, 0–29.3 months). Of all 3,047 patients, those with a suboptimal goal were 67.75%, 85.85%, and 33.64% for LDL-C, HDL-C, and TG levels, respectively. Multiple Cox regression analysis revealed there were significant increases in cumulative MACCE of 41% (HR = 1.41, 95% CI [1.09–1.82], p = 0.008), and revascularization of 48% (HR = 1.48, 95% CI [1.10–1.99], p = 0.01) in low HDL-C patients with ACS after PCI, but not the high TG group at the end of study. Conclusions. Our results showed there is high rate of dyslipidemia in Chinese ACS patients after PCI. Importantly, low HDL-C but not high TG levels are associated with higher MACCE and revascularization rates in ACS patients after PCI.