NHLBI Working Group Recommendations to Reduce Lipoprotein(a)-Mediated Risk of Cardiovascular Disease and Aortic Stenosis

Subjects with familial hypercholesterolemia have lower aortic valve area and higher levels of inflammatory biomarkers

BACKGROUND

Reduction of the aortic valve area (AVA) may lead to aortic valve stenosis with considerable impact on morbidity and mortality if not identified and treated. Lipoprotein (a) [Lp(a)] and also inflammatory biomarkers, including platelet derived biomarkers, have been considered risk factor for aortic stenosis; however, the association between Lp(a), inflammatory biomarkers and AVA among patients with familial hypercholesterolemia (FH) is not clear.

OBJECTIVE

We aimed to investigate the relation between concentration of Lp(a), measurements of the aortic valve including velocities and valve area and circulating inflammatory biomarkers in adult FH subjects and controls.

METHODS

In this cross-sectional study aortic valve measures were examined by cardiac ultrasound and inflammatory markers were analyzed in non-fasting blood samples. The study participants were 64 FH subjects with high (n = 29) or low (n = 35) Lp(a), and 14 healthy controls.

RESULTS

Aortic valve peak velocity was higher (p = 0.02), and AVA was lower (p = 0.04) in the FH patients compared to controls; however, when performing multivariable linear regression, there were no significant differences. Furthermore, there were no significant differences between the high and low FH Lp(a) groups regarding the aortic valve. FH subjects had higher levels of platelet-derived markers CD40L, PF4, NAP2 and RANTES compared to controls (0.003 ≤ P ≤ 0.03). This result persisted after multiple linear regression.

CONCLUSIONS

Middle-aged, intensively treated FH subjects have higher aortic valve velocity, lower AVA, and higher levels of the platelet-derived markers CD40L, PF4, NAP2 and RANTES compared to healthy control subjects. The aortic valve findings were not significant after multiple linear regression, whereas the higher levels of platelet-derived markers were maintained.

A Comparative Analysis of the Lipoprotein(a) and Low-Density Lipoprotein Proteomic Profiles Combining Mass Spectrometry and Mendelian Randomization

Background

Lipoprotein(a) (Lp[a]), which consists of a low-density lipoprotein (LDL) bound to apolipoprotein(a), is one of the strongest genetic risk factors for atherosclerotic cardiovascular diseases. Few studies have performed hypothesis-free direct comparisons of the Lp(a) and the LDL proteomes. Our objectives were to compare the Lp(a) and the LDL proteomic profiles and to evaluate the effect of lifelong exposure to elevated Lp(a) or LDL cholesterol levels on the plasma proteomic profile.

Methods

We performed a label-free analysis of the Lp(a) and LDL proteomic profiles of healthy volunteers in a discovery (n = 6) and a replication (n = 9) phase. We performed inverse variance weighted Mendelian randomization to document the effect of lifelong exposure to elevated Lp(a) or LDL cholesterol levels on the plasma proteomic profile of participants of the INTERVAL study.

Results

We identified 15 proteins that were more abundant on Lp(a) compared with LDL (serping1, pi16, itih1, itih2, itih3, pon1, podxl, cd44, cp, ptprg, vtn, pcsk9, igfals, vcam1, and ttr). We found no proteins that were more abundant on LDL compared with Lp(a). After correction for multiple testing, lifelong exposure to elevated LDL cholesterol levels was associated with the variation of 18 plasma proteins whereas Lp(a) did not appear to influence the plasma proteome.

Conclusions

Results of this study highlight marked differences in the proteome of Lp(a) and LDL as well as in the effect of lifelong exposure to elevated LDL cholesterol or Lp(a) on the plasma proteomic profile.

The interconnection between lipoprotein(a), lipoprotein(a) cholesterol and true LDL-cholesterol in the diagnosis of familial hypercholesterolemia

PURPOSE OF REVIEW

Elevated levels of lipoprotein(a) [Lp(a)] are present in 30-50% of patients with familial hypercholesterolemia. The contribution of Lp(a) towards risk stratification of patients with familial hypercholesterolemia has been recently recognized, with studies showing a significantly worse prognosis if Lp(a) is elevated. However, the role of elevated Lp(a) in diagnosis of familial hypercholesterolemia is less well defined or accepted.

RECENT FINDINGS

An important confounder in the diagnosis of familial hypercholesterolemia is the significant contribution of the cholesterol content on Lp(a) (Lp(a)-C) in individuals with elevated Lp(a). Because Lp(a)-C is incorporated into all clinical LDL-C measurements, it can contribute significantly to the cholesterol threshold diagnostic criteria for familial hypercholesterolemia used in most clinical algorithms.

SUMMARY

In this review, we discuss the interrelationship of Lp(a), Lp(a)-C and correct LDL-C in the diagnosis and prognosis of familial hypercholesterolemia. Future studies of accurately measuring correct LDL-C or in using apoB-100 and Lp(a) criteria may overcome the limitations of using estimated LDL-C in the diagnosis of familial hypercholesterolemia in individuals with concomitant elevation of Lp(a).

Low-Density Lipoprotein Cholesterol Corrected for Lipoprotein(a) Cholesterol, Risk Thresholds, and Cardiovascular Events

Background Conventional "low-density lipoprotein cholesterol (LDL-C)" assays measure cholesterol content in both low-density lipoprotein and lipoprotein(a) particles. To clarify the consequences of this methodological limitation for clinical care, our study aimed to compare associations of "LDL-C" and corrected LDL-C with risk of cardiovascular disease and to assess the impact of this correction on the classification of patients into guideline-recommended LDL-C categories. Methods and Results Lipoprotein(a) cholesterol content was estimated as 30% of lipoprotein(a) mass and subtracted from "LDL-C" to obtain corrected LDL-C values (LDL-Ccorr30). Hazard ratios for cardiovascular disease (defined as coronary heart disease, stroke, or coronary revascularization) were quantified by individual-patient-data meta-analysis of 5 statin landmark trials from the Lipoprotein(a) Studies Collaboration (18 043 patients; 5390 events; 4.7 years median follow-up). When comparing top versus bottom quartiles, the multivariable-adjusted hazard ratio for cardiovascular disease was significant for "LDL-C" (1.17; 95% CI, 1.05-1.31; P=0.005) but not for LDL-Ccorr30 (1.07; 95% CI, 0.93-1.22; P=0.362). In a routine laboratory database involving 531 144 patients, reclassification of patients across guideline-recommended LDL-C categories when using LDL-Ccorr30 was assessed. In "LDL-C" categories of 70 to <100, 100 to <130, 130 to <190, and ≥190 mg/dL, significant proportions (95% CI) of participants were reassigned to lower LDL-C categories when LDL-Ccorr30 was used: 30.2% (30.0%-30.4%), 35.1% (34.9%-35.4%), 32.9% (32.6%-33.1%), and 41.1% (40.0%-42.2%), respectively. Conclusions "LDL-C" was associated with incident cardiovascular disease only when lipoprotein(a) cholesterol content was included in its measurement. Refinement in techniques to accurately measure LDL-C, particularly in patients with elevated lipoprotein(a) levels, is warranted to assign risk to the responsible lipoproteins.

Does a ketogenic diet lower a very high Lp(a)? A striking experiment in a male physician

The level of lipoprotein(a) (Lp(a)), an important cardiovascular risk factor, is considered to be genetically determined. I am a 55-year-old male physician specialised in preventive medicine and a hobby triathlete with a body mass index of 24.9 kg/m² and a maximum oxygen consumption (VO₂max) of ~50 mL/(kg×min), with an average of 7-10 hours of exercise per week. I discovered my own Lp(a) at 92-97 mg/dL in 2004 and measured a maximum Lp(a) of 108 mg/dL in 2013. Surprisingly, I observed a much lower Lp(a) of 65 mg/dL in 2018. This happened after I had adopted a very-low-carb ketogenic diet for long-term endurance exercise. My n=1 experiment in July 2020 demonstrated an increase in Lp(a) back to 101 mg/dL on a very high-carb diet within 2 weeks, and a drop back to 74 mg/dL after 3 weeks on the ketogenic diet afterwards. The observed large changes in my Lp(a) were thus reproducible by a change in carbohydrate consumption and might have clinical relevance for patients as well as researchers in the field of Lp(a).

Lipoprotein(a) and High Sensitivity C-Reactive Protein among Patients with HIV in Ghana: The Study on Cardiovascular Risk Profile of HIV-Infected Patients on HAART (SCRIPT)

Background:

Lipoprotein(a) [Lp(a)] and high-sensitivity C-reactive protein (hs-CRP) levels are associated with cardiovascular disease (CVD) in the general population, even after adjusting for conventional CVD risk factors. However, data are limited regarding the distribution of Lp(a) and hs-CRP among patients with HIV in Ghana. We explored levels of Lp(a), hs-CRP and other cardiovascular risk factors among people who were HIV positive (HIV+) on ART (HIV+ART+), HIV+ART–, and HIV–ART– in a Ghanaian population.

Methods:

We conducted a cross sectional study, recruited individuals who were HIV+ART+ and HIV+ART– from the largest HIV clinic in central Ghana between August 2018 and December 2019. HIV negative controls were recruited from communities and adjoining suburbs of Kumasi. Lipoprotein(a) was measured using Immunoturbidimetric assay and high sensitive-CRP concentrations were determined using particle-enhanced turbidimetric assay. We compared levels of Lp(a), hs-CRP, and conventional CVD risk factors among these groups and used multivariable stepwise logistic regression models to explore associations between them.

Results:

Among HIV+ART+ (n = 156), HIV+ART– (n = 131), and HIV–ART– (n = 147), mean(SD) ages were 48 (9.1) years, 41 (11.1) years and 45 (11.9) years, p = <0.001, proportion of females were 71.2%, 67.9% and 73.5% respectively. Median(IQR) concentrations of hs-CRP in mg/L were 1.7 (0.8,4.5), 2.03 (0.5,8.58) and 1.0 (0.45,2.74) across respective groups and the proportion of elevated Lp(a) concentrations (Lp[a] > 30mg/dL) were 70%, 48% and 62% among HIV+ART+,HIV+ART– and HIV–ART– participants respectively. Diabetes mellitus, dyslipidemia, waist-to-hip ratio and metabolic syndrome were associated with higher hs-CRP levels. Compared to HIV–ART–, HIV+ patients had higher odds of having hs-CRP > 3mg/L while HIV+ART+ patients had higher odds of elevated Lp(a) than HIV+ART– after multivariable adjustment.

Conclusion:

PLWHA in Ghana are associated with higher odds of elevated hs-CRP, regardless of ART use. HIV+ART+ is significantly associated with higher odds of elevated Lp(a) levels compared to HIV+ART–; even after multivariable adjustments. Reasons for this and potential clinical implications merit further study.

The role of Lipoprotein(a) in cardiovascular disease: Current concepts and future perspectives

High lipoprotein(a) [Lp(a)] levels are associated with the development of atherosclerotic cardiovascular disease (ASCVD) and with calcific aortic valve stenosis (CAVS) both observationally and causally from human genetic studies. The mechanisms are not well characterized but likely involve its role as a carrier of oxidized phospholipids (OxPLs), which are known to be increased in pro-inflammatory states, to induce pro-inflammatory changes in monocytes leading to plaque instability, and to impair vascular endothelial cell function, a driver of acute and recurrent ischemic events. In addition, Lp(a) itself has prothrombotic activity. Current lipid-lowering strategies do not sufficiently lower Lp(a) serum levels. Lp(a)-specific-lowering drugs, targeting apolipoprotein(a) synthesis, lower Lp(a) by up to 90% and are being evaluated in ongoing clinical outcome trials. This review summarizes the current knowledge on the associations of Lp(a) with ASCVD and CAVS, the current role of Lp(a) assessment in the clinical setting, and emerging Lp(a)-specific-lowering therapies.

Lipoprotein(a) and cardiovascular disease: prediction, attributable risk fraction, and estimating benefits from novel interventions

AIMS 

To investigate the population attributable fraction due to elevated lipoprotein (a) (Lp(a)) and the utility of measuring Lp(a) in cardiovascular disease (CVD) risk prediction.

METHODS AND RESULTS 

In 413 734 participants from UK Biobank, associations of serum Lp(a) with composite fatal/non-fatal CVD (n = 10 066 events), fatal CVD (n = 3247), coronary heart disease (CHD; n = 18 292), peripheral vascular disease (PVD; n = 2716), and aortic stenosis (n = 901) were compared using Cox models. Median Lp(a) was 19.7 nmol/L (interquartile interval 7.6-75.3 nmol/L). About 20.8% had Lp(a) values >100 nmol/L; 9.2% had values >175 nmol/L. After adjustment for classical risk factors, 1 SD increment in log Lp(a) was associated with a hazard ratio for fatal/non-fatal CVD of 1.12 [95% confidence interval (CI) 1.10-1.15]. Similar associations were observed with fatal CVD, CHD, PVD, and aortic stenosis. Adding Lp(a) to a prediction model containing traditional CVD risk factors in a primary prevention group improved the C-index by +0.0017 (95% CI 0.0008-0.0026). In the whole cohort, Lp(a) above 100 nmol/L was associated with a population attributable fraction (PAF) of 5.8% (95% CI 4.9-6.7%), and for Lp(a) above 175 nmol/L the PAF was 3.0% (2.4-3.6%). Assuming causality and an achieved Lp(a) reduction of 80%, an ongoing trial to lower Lp(a) in patients with CVD and Lp(a) above 175 nmol/L may reduce CVD risk by 20.0% and CHD by 24.4%. Similar benefits were also modelled in the whole cohort, regardless of baseline CVD.

CONCLUSION 

Population screening for elevated Lp(a) may help to predict CVD and target Lp(a) lowering drugs, if such drugs prove efficacious, to those with markedly elevated levels.

Prognostic utility of lipoprotein(a) combined with fibrinogen in patients with stable coronary artery disease: a prospective, large cohort study

Background

Elevated lipoprotein(a) [Lp(a)] and fibrinogen (Fib) are both associated with coronary artery disease (CAD). The atherogenicity of Lp(a) can be partly due to the potentially antifibrinolytic categories. We hypothesize that patients with higher Lp(a) and Fib may have worse outcomes.

Methods

In this prospective study, we consecutively enrolled 8,417 Chinese patients with stable CAD from March 2011 to March 2017. All subjects were divided into 9 groups according to Lp(a) (Lp(a)-Low, Lp(a)-Medium, Lp(a)-High) and Fib levels (Fib-Low, Fib-Medium, Fib-High) and followed up for CVEs, including nonfatal acute myocardial infarction, stroke, and cardiovascular mortality. Kaplan–Meier, Cox regression and C-statistic analyses were performed.

Results

During a median of 37.1 months’ follow-up, 395 (4.7%) CVEs occurred. The occurrence of CVEs increased by Lp(a) (3.5 vs. 5.3 vs. 5.6%, p = 0.001) and Fib (4.0 vs. 4.4 vs. 6.1%, p < 0.001) categories. When further classified into 9 groups by Lp(a) and Fib levels, the CVEs were highest in the 9th (Lp(a)-High and Fib-High) compared with the 1st (Lp(a)-Low and Fib-Low) group (7.2 vs. 3.3%, p < 0.001). The highest risk of subsequent CVEs was found in the 9^th group (HR_adjusted 2.656, 95% CI 1.628–4.333, p < 0.001), which was more significant than Lp(a)-High (HR_adjusted 1.786, 95% CI 1.315–2.426, p < 0.001) or Fib-High (HR_adjusted 1.558, 95% CI 1.162–2.089, p = 0.003) group. Moreover, adding the combined Lp(a) and Fib increased the C-statistic by 0.013.

Conclusion

Combining Fib and Lp(a) enhance the prognostic value for incident CVEs beyond Lp(a) or Fib alone.

Serum lipoprotein (a) associates with a higher risk of reduced renal function: a prospective investigation

Lipoprotein (a) [Lp(a)] is a well-known risk factor for cardiovascular disease, but analysis on Lp(a) and renal dysfunction is scarce. We aimed to investigate prospectively the association of serum Lp(a) with the risk of reduced renal function, and further investigated whether diabetic or hypertensive status modified such association. Six thousand two hundred and fifty-seven Chinese adults aged ≤40 years and free of reduced renal function at baseline were included in the study. Reduced renal function was defined as estimated glomerular filtration rate <60 ml/min/1.73 m2 During a mean follow-up of 4.4 years, 158 participants developed reduced renal function. Each one-unit increase in log10-Lp(a) (milligrams per deciliter) was associated with a 1.99-fold (95% CI 1.15-3.43) increased risk of incident reduced renal function; the multivariable-adjusted odds ratio (OR) for the highest tertile of Lp(a) was 1.61 (95% CI 1.03-2.52) compared with the lowest tertile (P for trend = 0.03). The stratified analysis showed the association of serum Lp(a) and incident reduced renal function was more prominent in participants with prevalent diabetes [OR 4.04, 95% CI (1.42-11.54)] or hypertension [OR 2.18, 95% CI (1.22-3.89)]. A stronger association was observed in the group with diabetes and high Lp(a) (>25 mg/dl), indicating a combined effect of diabetes and high Lp(a) on the reduced renal function risk. An elevated Lp(a) level was independently associated with risk of incident reduced renal function, especially in diabetic or hypertensive patients.

Lipoprotein(a) and cardiovascular death in oldest-old (≥80 years) patients with acute myocardial infarction: A prospective cohort study

BACKGROUND AND AIMS

Compared with what is known about the prognostic value of lipoprotein(a) [Lp(a)] in middle-aged patients with atherosclerotic cardiovascular disease (ASCVD), less is understood concerning the role of Lp(a) in oldest-old (≥80 years old) with ASCVD. The aim of the present study was to investigate the relationship between Lp(a) and cardiovascular death (CD) among the oldest-old with acute myocardial infarction (AMI).

METHODS

A total of 1008 patients with AMI, older than 80 years, were consecutively enrolled between January 2012 and August 2018. The clinical characteristics were collected and Lp(a) concentrations were measured by the immunoturbidimetric method at baseline. The relationship between plasma Lp(a) concentration (≤10 mg/dL, 10-30 mg/dL, >30 mg/dL) and CD was evaluated by Kaplan-Meier analysis and Cox proportional hazard models.

RESULTS

During an average of 36.26 months of follow-up, 287 CD occurred. Data showed that patients with high Lp(a) levels (>30 mg/dL) had the highest rate of CD (p < 0.05). Kaplan-Meier analysis showed that the high Lp(a) group had the lowest event-free survival rate in the oldest-old with AMI (p = 0.030). In addition, subjects with Lp(a) > 30 mg/dL had a 1.5-fold (95% confidence interval: 1.083-2.132) higher risk of CD compared with those with Lp(a) ≤10 mg/dL in fully adjusted Cox proportional hazards model.

CONCLUSIONS

The current data firstly showed that plasma Lp(a) concentration was associated with the risk of CD in oldest-old with AMI, suggesting that Lp(a) could be a useful adjunctive measurement in the evaluation of CD in this population.

Generation and characterization of LPA-KIV9, a murine monoclonal antibody binding a single site on apolipoprotein (a)

Lipoprotein (a) [Lp(a)] is a risk factor for CVD and a target of therapy, but Lp(a) measurements are not globally standardized. Commercially available assays generally use polyclonal antibodies that detect multiple sites within the kringle (K)IV2 repeat region of Lp(a) and may lead to inaccurate assessments of plasma levels. With increasing awareness of Lp(a) as a cardiovascular risk factor and the active clinical development of new potential therapeutic approaches, the broad availability of reagents capable of providing isoform independence of Lp(a) measurements is paramount. To address this issue, we generated a murine monoclonal antibody that binds to only one site on apo(a). A BALB/C mouse was immunized with a truncated version of apo(a) that contained eight total KIV repeats, including only one copy of KIV2 We generated hybridomas, screened them, and successfully produced a KIV2-independent monoclonal antibody, named LPA-KIV9. Using a variety of truncated apo(a) constructs to map its binding site, we found that LPA-KIV9 binds to KIV9 without binding to plasminogen. Fine peptide mapping revealed that LPA-KIV9 bound to the sequence 4076LETPTVV4082 on KIV9 In conclusion, the generation of monoclonal antibody LPA-KIV9 may be a useful reagent in basic research studies and in the clinical application of Lp(a) measurements.

Gaps in the Care of Familial Hypercholesterolaemia in Australia: First Report From the National Registry

BACKGROUND

Familial hypercholesterolaemia (FH) is under-diagnosed and under-treated worldwide, including Australia. National registries play a key role in identifying patients with FH, understanding gaps in care and advancing the science of FH to improve care for these patients.

METHODS

The FH Australasia Network has established a national web-based registry to raise awareness of the condition, facilitate service planning and inform best practice and care services in Australia. We conducted a cross-sectional analysis of 1,528 FH adults enrolled in the registry from 28 lipid clinics.

RESULTS

The mean age at enrolment was 53.4±15.1 years, 50.5% were male and 54.3% had undergone FH genetic testing, of which 61.8% had a pathogenic FH-causing gene variant. Only 14.0% of the cohort were family members identified through cascade testing. Coronary artery disease (CAD) was reported in 28.0% of patients (age of onset 49.0±10.5 years) and 64.9% had at least one modifiable cardiovascular risk factor. The mean untreated LDL-cholesterol was 7.4±2.5 mmol/L. 80.8% of patients were on lipid-lowering therapy with a mean treated LDL-cholesterol of 3.3±1.7 mmol/L. Among patients receiving lipid-lowering therapies, 25.6% achieved an LDL-cholesterol target of <2.5 mmol/L without CAD or <1.8 mmol/L with CAD.

CONCLUSION

Patients in the national FH registry are detected later in life, have a high burden of CAD and risk factors, and do not achieve guideline-recommended LDL-cholesterol targets. Genetic and cascade testing are under-utilised. These deficiencies in care need to be addressed as a public health priority.

Association of lipoprotein(a) with platelet aggregation and thrombogenicity in patients undergoing percutaneous coronary intervention

This study aimed to evaluate the association of lipoprotein(a) levels with platelet aggregation and thrombogenicity in patients undergoing percutaneous coronary intervention (PCI), and to investigate the ischemic outcome on this population. Lipoprotein(a) and modified thrombelastography were measured in 6601 consecutive patients underwent PCI on dual antiplatelet therapy. Cox proportional regression analysis was applied to illustrate the ischemic events in a 2-year follow up. The mean levels of lipoprotein(a) were 29.0 mg/dl. Patients with higher lipoprotein(a) levels had significantly accelerated fibrin generation (lower K time and bigger α angle) and greater clot strength (higher maximum amplitude (MA)) than patients with lower lipoprotein(a) levels (P < .001). Moreover, the higher lipoprotein(a) group also exhibited significantly higher adenosine diphosphate (ADP) induced platelet aggregation (MA_ADP) by thrombelastography platelet mapping assay than lower lipoprotein(a) group. Cox regression analyzes revealed that patients with higher lipoprotein(a) levels had a 16% higher risk of major adverse cardiovascular and cerebrovascular events (HR 1.159, 95%CI: 1.005-1.337, P = .042) compared with patients with lower lipoprotein(a) levels. This association persisted after adjustment for a broad spectrum of risk factors (HR 1.174, 95%CI: 1.017-1.355, P = .028). High plasma lipoprotein(a) levels were associated with increased platelet aggregation and ischemic events in patients underwent PCI. Lipoprotein(a) might indicate the need for prolonged antiplatelet therapy.

Lipoprotein(a) as a predictor for the presence and severity of premature coronary artery disease: a cross-sectional analysis of 2433 patients

BACKGROUND

Lipoprotein(a) [Lp(a)] has been emerged as a risk factor for coronary artery disease (CAD), but there is currently insufficient data on the relationship between Lp(a) and premature CAD (PCAD). Thus, this study aimed to examine the association between Lp(a) and PCAD in a Chinese cohort.

METHODS

Data on 2433 individuals (male <55 years old and female <65 years old) who underwent coronary angiography from March 2016 to February 2019 were included in this study and were divided into the PCAD group (n = 1751) and non-CAD group (n = 682) according to the angiography results. Their clinical and laboratory parameters were collected, and plasma Lp(a) level was measured by immunoturbidimetry. The severity of CAD was evaluated using Gensini score (GS) and divided into three subgroups. The relationship between plasma Lp(a) levels and the presence and severity of PCAD was analyzed.

RESULTS

The level of plasma Lp(a) in the PCAD group was significantly higher than that in the non-CAD group (P < 0.001). The plasma Lp(a) concentration in the highest GS group was significantly higher than that in the lowest GS group (P < 0.001). Multivariate linear regression analysis showed that elevated plasma Lp(a) levels were correlated with higher GS (b = 0.41, P < 0.001). Multivariate logistic regression showed that elevated plasma Lp(a) levels were independently associated with PCAD (odds ratio = 2.91, P < 0.001). Moreover, elevated plasma Lp(a) levels correlated with higher GS (b = 0.41, P < 0.001).

CONCLUSION

In this study, Lp(a) concentration was associated with the presence and severity of PCAD, suggesting that Lp(a) may be a marker or target for patients with PCAD.

Effect of Alirocumab on Lipoprotein(a) and Cardiovascular Risk After Acute Coronary Syndrome

BACKGROUND

Lipoprotein(a) concentration is associated with cardiovascular events. Alirocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor, lowers lipoprotein(a) and low-density lipoprotein cholesterol (LDL-C).

OBJECTIVES

A pre-specified analysis of the placebo-controlled ODYSSEY Outcomes trial in patients with recent acute coronary syndrome (ACS) determined whether alirocumab-induced changes in lipoprotein(a) and LDL-C independently predicted major adverse cardiovascular events (MACE).

METHODS

One to 12 months after ACS, 18,924 patients on high-intensity statin therapy were randomized to alirocumab or placebo and followed for 2.8 years (median). Lipoprotein(a) was measured at randomization and 4 and 12 months thereafter. The primary MACE outcome was coronary heart disease death, nonfatal myocardial infarction, ischemic stroke, or hospitalization for unstable angina.

RESULTS

Baseline lipoprotein(a) levels (median: 21.2 mg/dl; interquartile range [IQR]: 6.7 to 59.6 mg/dl) and LDL-C [corrected for cholesterol content in lipoprotein(a)] predicted MACE. Alirocumab reduced lipoprotein(a) by 5.0 mg/dl (IQR: 0 to 13.5 mg/dl), corrected LDL-C by 51.1 mg/dl (IQR: 33.7 to 67.2 mg/dl), and reduced the risk of MACE (hazard ratio [HR]: 0.85; 95% confidence interval [CI]: 0.78 to 0.93). Alirocumab-induced reductions of lipoprotein(a) and corrected LDL-C independently predicted lower risk of MACE, after adjustment for baseline concentrations of both lipoproteins and demographic and clinical characteristics. A 1-mg/dl reduction in lipoprotein(a) with alirocumab was associated with a HR of 0.994 (95% CI: 0.990 to 0.999; p = 0.0081).

CONCLUSIONS

Baseline lipoprotein(a) and corrected LDL-C levels and their reductions by alirocumab predicted the risk of MACE after recent ACS. Lipoprotein(a) lowering by alirocumab is an independent contributor to MACE reduction, which suggests that lipoprotein(a) should be an independent treatment target after ACS. (ODYSSEY Outcomes: Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab; NCT01663402).

Efficacy and safety of add on therapies in patients with hypercholesterolemia undergoing statin therapy

INTRODUCTION

Statins are the first-line treatment to reduce cardiovascular (CV) events, mainly by reducing low-density-lipoprotein cholesterol (LDL-C), but many patients need additional treatments to reach the current lipid goals.

AREAS COVERED

Herein, the authors review the published literature on the efficacy and safety of the therapies that are most often added to statins to achieve lipid targets.

EXPERT OPINION

Ezetimibe is usually the first additional treatment to achieve LDL-C targets. It reduces LDL-C by about a further 20% and has an excellent safety and tolerability profile. The monoclonal antibody proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, evolocumab, and alirocumab, can reduce LDL-C by ≥50% when added to statins and they also have a well-established safety and tolerability record. The recently approved bempedoic acid is well tolerated and appears to be free of skeletal muscle-related problems, but the CV outcome study with this drug has not been completed. Inclisiran, a small-interfering RNA targeting PCSK9 is at an advanced stage of development and the available data indicate a satisfactory safety profile and LDL-C lowering efficacy similar to the PCSK9 monoclonal antibodies with the advantage of less frequent administration.

Future of preventing and managing common chronic inflammatory diseases

Chronic inflammation has emerged as a key factor that contributes to some common chronic diseases and reduces lifespan. Studies have identified multiple types of chronic inflammation ranging from autoimmune disease, which attacks specific tissues, to autoinflammatory diseases, which cause low-grade systemic inflammation and contribute to several common chronic diseases. This article highlights new perspectives on the role of chronic inflammation in cardiovascular disease (CVD). Such information is being leveraged to develop new treatment strategies for CVD and may inform how periodontal disease influences CVD.

Lipoprotein(a) and Its Potential Association with Thrombosis and Inflammation in COVID-19: a Testable Hypothesis

PURPOSE OF REVIEW

The COVID-19 pandemic has infected over > 11 million as of today people worldwide and is associated with significant cardiovascular manifestations, particularly in subjects with preexisting comorbidities and cardiovascular risk factors. Recently, a predisposition for arterial and venous thromboses has been reported in COVID-19 infection. We hypothesize that besides conventional risk factors, subjects with elevated lipoprotein(a) (Lp(a)) may have a particularly high risk of developing cardiovascular complications.

RECENT FINDINGS

The Lp(a) molecule has the propensity for inhibiting endogenous fibrinolysis through its apolipoprotein(a) component and for enhancing proinflammatory effects such as through its content of oxidized phospholipids. The LPA gene contains an interleukin-6 (IL-6) response element that may induce an acute phase-type increase in Lp(a) levels following a cytokine storm from COVID-19. Thus, subjects with either baseline elevated Lp(a) or those who have an increase following COVID-19 infection, or both, may be at very high risk of developing thromboses. Elevated Lp(a) may also lead to acute destabilization of preexisting but quiescent atherosclerotic plaques, which might induce acute myocardial infarction and stroke. Ongoing studies with IL-6 antagonists may be informative in understanding this relationship, and registries are being initiated to measure Lp(a) in subjects infected with COVID-19. If indeed an association is suggestive of being causal, consideration can be given to systematic testing of Lp(a) and prophylactic systemic anticoagulation in infected inpatients. Therapeutic lipid apheresis and pharmacotherapy for the reduction of Lp(a) levels may minimize thrombogenic potential and proinflammatory effects. We propose studies to test the hypothesis that Lp(a) may contribute to cardiovascular complications of COVID-19.

[Optimization of lipid-lowering therapy in patients after ischemic stroke. Resolution of the Council of Experts]

Hyperlipidemia is the main risk factor for diseases caused by atherosclerosis including ischemic stroke. This publication provides practical recommendations and an algorithm for prescribing lipid-lowering therapy to post-ischemic stroke patients. The algorithm presents the steps for sequential administration of statins, ezetimibe, and PCSK9 inhibitors to achieve target levels of low-density lipoprotein cholesterol.

Lipoprotein(a): Expanding our knowledge of aortic valve narrowing

Elevated levels of lipoprotein(a) [Lp(a)] have been identified as an independent and causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and, more recently, calcific aortic valve disease (CAVD). CAVD is a slow, progressive disorder presenting as severe trileaflet calcification known as aortic valve stenosis (AS) that impairs valve motion and restricts ventricular outflow. AS afflicts 2% of the aging population (≥ 65 years) and tends to be quite advanced by the time it presents clinical symptoms of exertional angina, syncope, or heart failure. Currently, the only effective clinical therapy for AS patients is surgical or transcatheter aortic valve replacement. Evidence is accumulating that Lp(a) can exacerbate pathophysiological processes in CAVD, specifically, endothelial dysfunction, formation of foam cells, and promotion of a pro-inflammatory state. In the valve milieu, the pro-inflammatory effects of Lp(a) are manifested in valve thickening and mineralization through pro-osteogenic signaling and changes in gene expression in valve interstitial cells that is primarily facilitated by the oxidized phospholipid content of Lp(a). In AS pathogenesis, an incomplete understanding of the role of Lp(a) at the molecular level and the absence of appropriate animal models are barriers for the development of specific and effective clinical interventions designed to mitigate the role of Lp(a) in AS. However, the advent of effective therapies that dramatically lower Lp(a) provides the possibility of the first medical treatment to halt AS progression.

Lipoprotein(a) and Atherosclerotic Cardiovascular Disease: Current Understanding and Future Perspectives

PURPOSE

To review current knowledge of elevated lipoprotein(a) [Lp(a)] levels in relation to atherosclerotic cardiovascular disease (ASCVD) and discuss their potential use as biomarkers and therapeutic approaches in clinical practice.

METHODS

We summarized the current understanding and recent advances in the structure, metabolism, atherogenic mechanisms, standardized laboratory measurement, recommended screening populations, and prognostic value of Lp(a), with a special focus on the current potential treatment approaches for hyperlipoprotein(a)emia in patients with ASCVD.

RESULTS

Lp(a) is composed of LDL-like particle and characteristic apolipoprotein(a) [apo(a)] connected by a disulfide bond. Substantial evidence shows that elevated plasma Lp(a) level is a heritable, independent, and possibly causal risk factor for ASCVD through its proatherogenic, proinflammatory, and potentially prothrombotic properties. Current guidelines recommend Lp(a) measurement for patients with an intermediate-high risk of ASCVD, familial hypercholesterolemia, a family history of early ASCVD or elevated Lp(a), and progressive ASCVD despite receiving optimal therapy. Traditional Lp(a)-lowering approaches such as niacin, PCSK9 inhibitors, mipomersen, lomitapide, and lipoprotein apheresis were associated with a non-specific and limited reduction of Lp(a), intolerable side effects, invasive procedure, and high expense. The phase 2 randomized controlled trial of antisense oligonucleotide against the apo(a) encoding gene LPA mRNA showed that IONIS-APO(a)-L_RX could specifically reduce the level of Lp(a) by 90% with good tolerance, which may become a promising candidate for the prevention and treatment of ASCVD in the future.

CONCLUSIONS

It is reasonable to measure Lp(a) levels to reclassify ASCVD risk and manage individuals with elevated Lp(a) to further reduce the residual risk of ASCVD, especially with IONIS-APO(a)-L_RX.

PCSK9 Inhibition with alirocumab increases the catabolism of lipoprotein(a) particles in statin-treated patients with elevated lipoprotein(a)

BACKGROUND

Lipoprotein(a) (Lp(a)) is a low-density lipoprotein (LDL) particle containing apolipoprotein(a) (apo(a)) covalently linked to apolipoprotein B-100 (apoB). Statin-treated patients with elevated Lp(a) have an increased risk of atherosclerotic cardiovascular disease (ASCVD). Recent trials show that proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition decreases Lp(a) and cardiovascular events, particularly in high risk patients with elevated Lp(a). We investigated the kinetic mechanism whereby alirocumab, a PCSK9 inhibitor, lowers Lp(a) in statin-treated patients with high Lp(a) and ASCVD.

METHODS

The effects of 12-week alirocumab treatment (150 mg every 2 weeks) on apo(a) kinetics were studied in 21 patients with elevated Lp(a) concentration (>0.5 g/L). Apo(a) fractional catabolic rate (FCR) and production rate (PR) were determined using intravenous D3-leucine administration, mass spectrometry and compartmental modelling. All patients were on long-term statin treatment.

RESULTS

Alirocumab significantly decreased plasma concentrations of total cholesterol (-39%), LDL-cholesterol (-67%), apoB (-56%), apo(a) (-25%) and Lp(a) (-22%) (P< 0.001 for all). Alirocumab also significantly lowered plasma apo(a) pool size (-26%, P <0.001) and increased the FCR of apo(a) (+28%, P< 0.001), but did not alter apo(a) PR, which remained significantly higher relative to a reference group of patients on statins with normal Lp(a) (P< 0.001).

CONCLUSIONS

In statin-treated patients, alirocumab lowers elevated plasma Lp(a) concentrations by accelerating the catabolism of Lp(a) particles. This may be consequent on marked upregulation of hepatic receptors (principally for LDL) and/or reduced competition between Lp(a) and LDL particles for these receptors; the mechanism could contribute to the benefit of PCSK9 inhibition with alirocumab on cardiovascular outcomes.

Lipoprotein(a) - Marker for cardiovascular risk and target for lipoprotein apheresis

Lipoprotein(a) (Lp(a)) consists of an LDL particle whose apolipoprotein B (apoB) is covalently bound to apolipoprotein(a) (apo[a]). An increased Lp(a) concentration is a causal, independent risk factor for atherosclerotic cardiovascular disease (ASCVD) and a predictor of incident or recurrent cardiovascular events. Although Lp(a) was first described as early as 1963, only the more recent results of epidemiological, molecular, and genetic studies have led to this unequivocal conclusion. More than 20% of Western populations have elevated Lp(a) values. Lp(a) concentrations should be always part of the lipid profile when ASCVD risk is assessed. However, presence of other risk factors, laboratory findings, medical history and family history must be considered to conclude on its clinical relevance in an individual patient. Early or progressive ASCVD or a familial predisposition are key findings which can be associated with elevated Lp(a). The cholesterol portion contained in Lp(a) is also included in the various methods of LDL-C measurement. To assess proximity to the cardiovascular risk related target value for LDL-C, appropriate correction should be applied when high Lp(a) values are obtained to estimate the LDL-C that can actually be treated by lipid lowering drugs. Initial study data show that antisense oligonucleotides, which selectively decrease apolipoprotein(a), are promising as future treatment options. Currently, lipoprotein apheresis, which has a reimbursement guideline in Germany, is the therapy of choice for patients with Lp(a)-associated progressive ASCVD, with the aim of sustained prevention of further cardiovascular events.

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.

Lipoprotein(a) and Cardiovascular Diseases - Revisited

Two decades ago, it was recognized that lipoprotein(a) (Lp(a)) concentrations were elevated in patients with cardiovascular disease (CVD). However, the importance of Lp(a) was not strongly established due to a lack of both Lp(a)-lowering therapy and evidence that reducing Lp(a) levels improves CVD risk. Recent advances in clinical and genetic research have revealed the crucial role of Lp(a) in the pathogenesis of CVD. Mendelian randomization studies have shown that Lp(a) concentrations are causal for different CVDs, including coronary artery disease, calcified aortic valve disease, stroke, and heart failure, despite optimal low-density lipoprotein cholesterol (LDL-C) management. Lp(a) consists of apolipoprotein (apo) B100 covalently bound to apoA. Thus, Lp(a) has atherothrombotic traits of both apoB (from LDL) and apoA (thrombo-inflammatory aspects). Although conventional pharmacological therapies, such as statin, niacin, and cholesteryl ester transfer protein, have failed to significantly reduce Lp(a) levels, emerging new therapeutic strategies using proprotein convertase subtilisin-kexin type 9 inhibitors or antisesnse oligonucleotide technology have shown promising results in effectively lowering Lp(a). In this review we discuss the revisited important role of L(a) and strategies to overcome residual risk in the statin era.

Lipoprotein(a) Cellular Uptake Ex Vivo and Hepatic Capture In Vivo Is Insensitive to PCSK9 Inhibition With Alirocumab

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Modulating LDL receptor expression genetically (in familial hypercholesterolemia) or pharmacologically (using statins or the PCSK9 inhibitor alirocumab) does not alter the cellular uptake of Lp(a) in primary human lymphocytes.

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Lp(a) hepatic capture is not modulated by PCSK9 inhibition with alirocumab in liver-humanized mice.

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LDLR does not appear to play a significant role in mediating Lp(a) plasma clearance in vivo.

Lipoprotein(a) (Lp[a]) is the most common genetically inherited risk factor for cardiovascular disease. Many aspects of Lp(a) metabolism remain unknown. We assessed the uptake of fluorescent Lp(a) in primary human lymphocytes as well as Lp(a) hepatic capture in a mouse model in which endogenous hepatocytes have been ablated and replaced with human ones. Modulation of LDLR expression with the PCSK9 inhibitor alirocumab did not alter the cellular or the hepatic uptake of Lp(a), demonstrating that the LDL receptor is not a major route for Lp(a) plasma clearance. These results have clinical implications because they underpin why statins are not efficient at reducing Lp(a).

PCSK9 Inhibitors in Secondary Prevention-An Opportunity for Personalized Therapy

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death worldwide. Low-density lipoprotein cholesterol (LDL-C) is the primary cause of ASCVD and reducing LDL-C levels with statin therapy significantly reduces ASCVD risk; however, significant residual risk remains. Two monoclonal antibodies (mAbs), alirocumab and evolocumab, that target proprotein convertase subtilisin/kexin-type 9 (PCSK9), reduce LDL-C levels by up to 60% when used in combination with statins and significantly reduce the risk of recurrent ASCVD events in both stable secondary prevention and acute coronary syndrome populations. Prespecified analyses of recent randomized controlled trials have shed light on how best to prioritize these therapies to maximize their value in select high-risk groups. These data have also informed recent clinical practice guidelines and scientific statements resulting in an expanded role for PCSK9-mAbs compared with previous guidelines, albeit there are notable differences between these recommendations. Ongoing research is exploring the long-term safety of PCSK9-mAbs and their role in the acute setting and patients without prior myocardial infarction or stroke. Novel therapies that inhibit PCSK9 synthesis via small interfering RNA, such as inclisiran, are also in development and may reduce LDL-C levels similar to PCSK9-mAbs, but with less frequent administration. Nonetheless, the PCSK9-mAbs are a breakthrough therapy and warrant consideration in very high-risk patients who are most likely to benefit. Such a personalized approach can help to ensure cost-effectiveness and maximize their value.

The Prevalence of Elevated Lipoprotein(a) in Patients Presenting With Coronary Artery Disease

BACKGROUND

Elevated lipoprotein(a) (Lp(a)) is an inherited lipid disorder and an independent risk factor for cardiovascular (CV) disease. Although its prevalence in the general population has been well-documented, the prevalence of elevated Lp(a) in patients with clinical coronary artery disease (CAD) is less clear. In this study, we hypothesised that there is an over-representation of elevated Lp(a) in patients with early-onset CAD compared to the general population.

METHODS

Between 6 February and 8 June 2018, we screened consecutive patients aged ≤70 years who presented to the Austin Hospital with any of the following criteria: (1) acute coronary syndrome (ACS); (2) percutaneous coronary intervention (PCI); or (3) coronary artery bypass grafting (CABG). Whilst examining a range of different Lp(a) levels, a dichotomous elevated Lp(a) was defined as concentrations ≥0.5 g/L. Other CV risk factors were documented including hypertension, type 2 diabetes mellitus, and familial hypercholesterolaemia (FH) using the Dutch Lipid Clinic Network Criteria (DLCNC), also incorporating family history and clinical examination.

RESULTS

One hundred and fifty-eight (158) patients were screened; 63 (39.9%) were under 60 years of age. Overall, elevated Lp(a) ≥0.5 g/L was identified in 57 patients (36.1%). Of these, nine patients (15.8%) also had probable or definite FH. General population data was obtained from the Copenhagen General Population Study which studied 6,000 men and women and showed that the estimated prevalence of Lp(a) ≥0.5 g/L in the general population was 20%.

CONCLUSIONS

Elevated Lp(a) is more prevalent in patients with relatively early-onset CAD compared to the general population and may contribute to previously unappreciated residual cardiovascular risk. Patients who present with early-onset CAD, should be routinely screened for elevated Lp(a).

Pharmacokinetics of current and emerging treatments for hypercholesterolemia

Introduction: Reduction of low-density-lipoprotein cholesterol (LDL-C) and other apolipoprotein B (apoB)-containing lipoproteins reduces cardiovascular (CV) events and greater reductions have greater benefits. Current lipid treatments cannot always achieve desirable LDL-C targets and additional or alternative treatments are often needed.Areas covered: In this article, we review the pharmacokinetics of the available and emerging treatments for hypercholesterolemia and focus on recently approved drugs and those at a late stage of development.Expert opinion: Statin pharmacokinetics are well known and appropriate drugs and doses can usually be chosen for individual patients to achieve LDL-C targets and avoid adverse effects and drug-drug interactions. Ezetimibe, icosapent ethyl and the monoclonal antibodies evolocumab and alirocumab have established efficacy and safety. Newer oral agents including pemafibrate and bempedoic acid have generally favorable pharmacokinetics supporting use in a wide range of patients. RNA-based therapies with antisense oligonucleotides are highly specific for their targets and those inhibiting apoB, apoCIII, angiopoietin-like protein 3 and lipoprotein(a) have shown promising results. The small-interfering RNA inclisiran has the notable advantage that a single subcutaneous administration may be effective for up to 6 months. The CV outcome trial results and long term safety data are eagerly awaited for these new agents.

Peripheral Artery Disease and Venous Thromboembolic Events After Acute Coronary Syndrome: Role of Lipoprotein(a) and Modification by Alirocumab: Prespecified Analysis of the ODYSSEY OUTCOMES Randomized Clinical Trial

Supplemental Digital Content is available in the text.

Patients with acute coronary syndrome are at risk for peripheral artery disease (PAD) events and venous thromboembolism (VTE). PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitors reduce lipoprotein(a) and low-density lipoprotein cholesterol (LDL-C) levels. Our objective was to ascertain whether PCSK9 inhibition reduces the risk of PAD events or VTE after acute coronary syndrome, and if such effects are related to levels of lipoprotein(a) or LDL-C.

Elevated Lipoprotein A in South Asians and the Associated Risk of Cardiovascular Disease: A Systematic Review

BACKGROUND

South Asians have a premature risk of cardiovascular disease and increased lipoprotein A which enhances their risk.

METHODS

This systematic review evaluates the role of elevated lipoprotein A in cardiovascular disease risk for South Asians. It discusses the pathophysiology, clinical studies, and treatment of elevated lipoprotein A using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method.

RESULTS

A total of 72 articles was incorporated which consisted of clinical studies, case-control and cohort studies, meta-analysis, reviews, and editorials. Cardiovascular disease and myocardial infarction occurs prematurely in South Asians, which is further enhanced with an elevated lipoprotein A.

CONCLUSIONS

South Asians with an elevated lipoprotein A have an increased risk of coronary artery disease so they should have early enactment of lifestyle modification and aggressive medical management.

Advanced fibrosis of non-alcoholic steatohepatitis affects the significance of lipoprotein(a) as a cardiovascular risk factor

BACKGROUND AND AIMS

Lipoprotein(a) [Lp(a)] is an important independent cardiovascular risk factor. However, Lp(a) levels are lower in patients with chronic liver disease than in healthy subjects. Furthermore, Lp(a) levels decrease as residual liver function declines. Although non-alcoholic fatty liver disease (NAFLD), especially advanced non-alcoholic steatohepatitis (NASH), increases the risk of cardiovascular diseases, the relationship between serum Lp(a) level and NASH is unknown. Thus, we examined the relationship between serum Lp(a) levels and biopsy-proved NAFLD and clarified the significance of Lp(a) measurements for cardiovascular disease screening in patients with NAFLD.

METHODS

A total of 176 patients with NAFLD were enrolled. Comprehensive blood chemistry tests and histological examinations of liver samples were conducted. The relationship between serum Lp(a) levels and NAFLD was analyzed.

RESULTS

Serum Lp(a) levels in advanced fibrosis (stage 3-4) were lower than those in non-advanced fibrosis (stage 0-2) (p < 0.05). After adjustment for age, sex, body mass index, alanine aminotransferase (ALT), creatinine (Cre), HbA_1c level, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and the use of lipid-lowering agents, the significant inverse association between advanced fibrosis and serum Lp(a) levels remained (p < 0.01). Although the Lp(a) level was inversely associated with an NAFLD Activity Score (NAS) of 5-8, there was no significant association between Lp(a) levels and NAS adjusted for age, sex, body mass index, ALT, Cre, HbA_1c level, HDL-C, LDL-C, TG, and the use of lipid-lowering agents.

CONCLUSIONS

Advanced NASH is associated with low serum Lp(a) levels; therefore, Lp(a) levels may not be useful in evaluating cardiovascular risk.

Effect of Evolocumab on Non-High-Density Lipoprotein Cholesterol, Apolipoprotein B, and Lipoprotein(a): A Pooled Analysis of Phase 2 and Phase 3 Studies

Background

Dyslipidemia guidelines recommend non‐high‐density lipoprotein cholesterol (non‐HDL‐C) and apolipoprotein B (ApoB) as additional targets of therapy and consider lipoprotein(a) a significant cardiovascular risk marker. The current analysis evaluates the effects of evolocumab on these parameters in various patient populations over time.

Methods and Results

Data from 7690 patients, 4943 of whom received at least 1 dose of evolocumab, in 15 phase 2 and phase 3 studies with a duration ranging from 12 weeks to 5 years were pooled based on study length, patient population, and ezetimibe or placebo comparator groups. Patients could receive intensive statin therapy but not in the statin intolerance and monotherapy studies. The effects of evolocumab on percent change from baseline for non‐HDL‐C, ApoB, and lipoprotein(a) and achievement of treatment goals for non‐HDL‐C and ApoB were examined. Compared with placebo, evolocumab at both approved dosing regimens substantially reduced mean non‐HDL‐C (Q2W dose: −49% to −56%, monthly dose: −48% to −52%), mean ApoB (Q2W dose: −46% to −52%, monthly dose: −40% to −48%), and median lipoprotein(a) (Q2W dose: −22% to −38%, monthly dose: −20% to −33%) at 12 weeks. Effects on all 3 parameters persisted over 5 years. Lipid‐lowering effects were consistent among the patient populations examined (hypercholesterolemia/mixed dyslipidemia, statin intolerance, heterozygous familial hypercholesterolemia, and type 2 diabetes mellitus).

Conclusions

In this pooled analysis, evolocumab substantially reduced non‐HDL‐C, ApoB, and lipoprotein(a) compared with placebo. The effect was consistent and maintained in various patient populations over 5 years.

VLDL (Very-Low-Density Lipoprotein)-Apo E (Apolipoprotein E) May Influence Lp(a) (Lipoprotein [a]) Synthesis or Assembly

Objective:

To clarify the association between PCSK9 (proprotein convertase subtilisin/kexin type 9) and Lp(a) (lipoprotein [a]), we studied Lp(a) kinetics in patients with loss-of-function and gain-of-function PCSK9 mutations and in patients in whom extended-release niacin reduced Lp(a) and PCSK9 concentrations.

Approach and Results:

Six healthy controls, 9 heterozygous patients with familial hypercholesterolemia (5 with low-density lipoprotein receptor [ LDLR ] mutations and 4 with PCSK9 gain-of-function mutations) and 3 patients with heterozygous dominant-negative PCSK9 loss-of-function mutations were included in the preliminary study. Eight patients were enrolled in a second study assessing the effects of 2 g/day extended-release niacin. Apolipoprotein kinetics in VLDL (very-low-density lipoprotein), LDL (low-density lipoprotein), and Lp(a) were studied using stable isotope techniques. Plasma Lp(a) concentrations were increased in PCSK9 -gain-of-function and familial hypercholesterolemia- LDLR groups compared with controls and PCSK9 -loss-of-function groups (14±12 versus 5±4 mg/dL; P =0.04), but no change was observed in Lp(a) fractional catabolic rate. Subjects with PCSK9 -loss-of-function mutations displayed reduced apoE (apolipoprotein E) concentrations associated with a VLDL-apoE absolute production rate reduction. Lp(a) and VLDL-apoE absolute production rates were correlated ( r =0.50; P <0.05). ApoE-to-apolipoprotein (a) molar ratios in Lp(a) increased with plasma Lp(a) ( r =0.96; P <0.001) but not with PCSK9 levels. Extended-release niacin-induced reductions in Lp(a) and VLDL-apoE absolute production rate were correlated ( r =0.83; P =0.015). In contrast, PCSK9 reduction (−35%; P =0.008) was only correlated with that of VLDL-apoE absolute production rate ( r =0.79; P =0.028).

Conclusions:

VLDL-apoE production could determine Lp(a) production and/or assembly. As PCSK9 inhibitors reduce plasma apoE and Lp(a) concentrations, apoE could be the link between PCSK9 and Lp(a).

Evolving concepts on the management of dyslipidaemia

It has been well established that low-density lipoproteins (LDL) and other apolipoprotein B-containing lipoproteins are causally related to atherosclerotic cardiovascular disease (ASCVD) and that lowering these lipoproteins reduces the risk of ASCVD. By lowering LDL particles as much as possible, ASCVD can be prevented. There seems to be no LDL-cholesterol (LDL-C) threshold below which no further ASCVD prevention can be achieved. Furthermore, a low (an even very low) LDL-C appears to be safe. The new ESC/EAS guidelines based on these concepts are a step towards a benefit-based strategy by focusing on the clinical benefit that can be achieved by treating the cause of ASCVD. It is recommended to lower LDL-C as much as possible to prevent ASCVD, especially in high and very high-risk patients. With these new recommendations come recognition of the importance of combination therapies in high and very high-risk patients, first with statins and ezetimibe, and if needed with a PCSK9 inhibitor. The present paper is a review of some new concepts arising during the past 10 years in the field of lipidology and the description of what is new in the 2019 EAS/ESC guidelines.

Lipoprotein(a) Reduction in Persons with Cardiovascular Disease

BACKGROUND

Lipoprotein(a) levels are genetically determined and, when elevated, are a risk factor for cardiovascular disease and aortic stenosis. There are no approved pharmacologic therapies to lower lipoprotein(a) levels.

METHODS

We conducted a randomized, double-blind, placebo-controlled, dose-ranging trial involving 286 patients with established cardiovascular disease and screening lipoprotein(a) levels of at least 60 mg per deciliter (150 nmol per liter). Patients received the hepatocyte-directed antisense oligonucleotide AKCEA-APO(a)-L_Rx, referred to here as APO(a)-L_Rx (20, 40, or 60 mg every 4 weeks; 20 mg every 2 weeks; or 20 mg every week), or saline placebo subcutaneously for 6 to 12 months. The lipoprotein(a) level was measured with an isoform-independent assay. The primary end point was the percent change in lipoprotein(a) level from baseline to month 6 of exposure (week 25 in the groups that received monthly doses and week 27 in the groups that received more frequent doses).

RESULTS

The median baseline lipoprotein(a) levels in the six groups ranged from 204.5 to 246.6 nmol per liter. Administration of APO(a)-L_Rx resulted in dose-dependent decreases in lipoprotein(a) levels, with mean percent decreases of 35% at a dose of 20 mg every 4 weeks, 56% at 40 mg every 4 weeks, 58% at 20 mg every 2 weeks, 72% at 60 mg every 4 weeks, and 80% at 20 mg every week, as compared with 6% with placebo (P values for the comparison with placebo ranged from 0.003 to <0.001). There were no significant differences between any APO(a)-L_Rx dose and placebo with respect to platelet counts, liver and renal measures, or influenza-like symptoms. The most common adverse events were injection-site reactions.

CONCLUSIONS

APO(a)-L_Rx reduced lipoprotein(a) levels in a dose-dependent manner in patients who had elevated lipoprotein(a) levels and established cardiovascular disease. (Funded by Akcea Therapeutics; ClinicalTrials.gov number, NCT03070782.).