PCSK9-directed therapies: an update.

PURPOSE OF REVIEW: Two large cardiovascular outcomes trials of monoclonal antibodies against proprotein convertase subtilisin/kexin type 9 (PCSK9) demonstrated that therapeutic inhibition of extracellular PCSK9 markedly reduces LDL cholesterol concentration and cardiovascular risk. Several novel strategies to inhibit PCSK9 function are in development. Different mechanisms of action may determine specific properties with potential relevance for patient care. RECENT FINDINGS: For the monoclonal antibodies evolocumab und alirocumab as first-generation PCSK9 inhibitors, follow-up data of up to 8 years of exposure complement the information on efficacy and safety available from outcome trials. For the small-interfering RNA inclisiran as second-generation PCSK9 inhibitor, several phase III trials have been published and a cardiovascular outcome trial has completed recruitment and is ongoing. Third-generation PCSK9 inhibitors encompass, among others, orally available drugs such as MK-0616 and the fusion protein lerodalcibep. Additional strategies to inhibit PCSK9 include vaccination and gene editing. SUMMARY: Long-term inhibition of PCSK9 with monoclonal antibodies is safe and conveys sustained cardiovascular benefit. Novel strategies to inhibit PCSK9 function such as orally available drugs, RNA targeting, and one-time treatment with gene editing may further enhance the therapeutic armamentarium and enable novel preventive strategies.

Clinical and genetic diagnosis of familial hypercholesterolaemia in patients undergoing coronary angiography: the Ludwigshafen Risk and Cardiovascular Health Study.

AIMS: To investigate the prevalence of familial hypercholesterolaemia (FH) and compare the performance of clinical criteria and genetic testing in patients undergoing coronary angiography. METHODS: The prevalence of FH was determined with the Dutch Lipid Clinical Network (DLCN), US-MEDPED, Simon Broome (SB) criteria, the 'Familial Hypercholesterolaemia Case Ascertainment Tool' (FAMCAT), and a clinical algorithm. Genetic screening was conducted with a custom array from Affymetrix (CARRENAL array) harboring 944 FH mutations. RESULTS: The study cohort consisted of 3267 patients (78.6% with coronary artery disease [CAD]). FH was diagnosed in 2.8%, 2.2%, 3.9%, and 7.9% using the DLCN, US-MEDPED, SB criteria, and the FAMCAT. The clinical algorithm identified the same patients as the SB criteria. Pathogenic FH mutations were found in 1.2% (1.2% in patients with CAD, 1.0% in patients without CAD). FH was more frequently diagnosed in younger patients. With genetic testing as reference, the clinical criteria achieved areas under the ROC curve (AUCs) in the range of 0.56-0.68. Using only LDL-C corrected for statin intake, an AUC of 0.68 was achieved. CONCLUSION: FH is up to fourfold more prevalent in patients undergoing coronary angiography than in contemporary cohorts representing the general population. Different clinical criteria yield substantially different diagnosis rates, overestimating the prevalence of FH compared to genetic testing. LDL-C testing alone may be sufficient to raise the suspicion of FH, which then needs to be corroborated by genetic testing.

LDL cholesterol target attainment in cardiovascular high- and very-high-risk patients with statin intolerance: a simulation study.

The inability to tolerate sufficient doses of statins, statin intolerance (SI), contributes to the non-achievement of guideline-recommended low-density lipoprotein cholesterol (LDL-C) treatment targets. Patients with SI require alternative lipid-lowering therapies (LLT). We conducted a simulation study on LDL-C target achievement with oral LLT (ezetimibe, bempedoic acid) in patients with SI, using representative data of 2.06 million German outpatients. SI was defined using literature-informed definitions based on electronic medical records (EMR). Among n = 130,778 patients with hypercholesterolaemia, available LDL-C measurement, and high or very-high cardiovascular risk, 8.6% met the definition of SI. Among patients with SI, 7.7% achieved the LDL-C target at baseline. After simulation of the stepwise addition of treatment with ezetimibe and bempedoic acid, 22.6 and 52.0% achieved the LDL-C target, respectively. The median achieved LDL-C was 80 and 62 mg/dL, the corresponding reductions from baseline were 20.0 and 38.0%, respectively. A higher proportion of patients classified as high risk achieved the target compared to those at very-high risk (58.1 vs. 49.9%). In conclusion, in patients with increased cardiovascular risk meeting the definition of SI based on EMR, combination LLT with ezetimibe and bempedoic acid has the potential to substantially increase the proportion of patients achieving clinically relevant LDL-C reductions.

The German CaRe high registry for familial hypercholesterolemia - Sex differences, treatment strategies, and target value attainment.

Background and aims: Familial hypercholesterolemia (FH) is among the most common genetic disorders in primary care. However, only 15% or less of patients are diagnosed, and few achieve the goals for low-density lipoprotein cholesterol (LDL-C). In this analysis of the German Cascade Screening and Registry for High Cholesterol (CaRe High), we examined the status of lipid management, treatment strategies, and LDL-C goal attainment according to the ESC/EAS dyslipidemia guidelines. Methods: We evaluated consolidated datasets from 1501 FH patients diagnosed clinically and seen either by lipid specialists or general practitioners and internists. We conducted a questionnaire survey of both the recruiting physicians and patients. Results: Among the 1501 patients, 86% regularly received lipid-lowering drugs. LDL-C goals were achieved by 26% and 10% of patients with atherosclerotic cardiovascular disease (ASCVD) according to the 2016 and 2019 ESC/EAS dyslipidemia guidelines, respectively. High intensity lipid-lowering was administered more often in men than in women, in patients with ASCVD, at higher LDL-C and in patients with a genetic diagnosis of FH. Conclusions: FH is under-treated in Germany compared to guideline recommendations. Male gender, genetic proof of FH, treatment by a specialist, and presence of ASCVD appear to be associated with increased treatment intensity. Achieving the LDL-C goals of the 2019 ESC/EAS dyslipidemia guidelines remains challenging if pre-treatment LDL-C is very high.

Simulation study on LDL cholesterol target attainment, treatment costs, and ASCVD events with bempedoic acid in patients at high and very-high cardiovascular risk.

BACKGROUND AND AIMS: The LDL cholesterol (LDL-C) treatment goals recommended by the 2019 ESC/EAS guidelines are only achieved in a minority of patients. The study objective was to estimate the impact of bempedoic acid treatment on LDL-C target attainment, drug costs, and atherosclerotic cardiovascular disease (ASCVD) events. The simulation used a Monte Carlo approach in a representative cohort of German outpatients at high or very-high cardiovascular risk. Additionally to statins, consecutive treatment with ezetimibe, bempedoic acid, and a PCSK9 inhibitor was simulated in patients not achieving their LDL-C goal. Considered were scenarios without and with bempedoic acid (where bempedoic acid was replaced by a PCSK9 inhibitor when LDL-C was not controlled). RESULTS: The simulation cohort consisted of 105,577 patients, of whom 76,900 had very-high and 28,677 high cardiovascular risk. At baseline, 11.2% of patients achieved their risk-based LDL-C target. Sequential addition of ezetimibe and bempedoic acid resulted in target LDL-C in 33.1% and 61.9%, respectively. Treatment with bempedoic acid reduced the need for a PCSK9 inhibitor from 66.6% to 37.8% and reduced drug costs by 35.9% per year on stable lipid-lowering medication. Compared to using only statins and ezetimibe, this approach is projected to prevent additional 6,148 ASCVD events annually per 1 million patients, whereas PCSK9 inhibition alone would prevent 7,939 additional ASCVD events annually. CONCLUSIONS: A considerably larger proportion of cardiovascular high- and very-high-risk patients can achieve guideline-recommended LDL-C goals with escalated lipid-lowering medication. Bempedoic acid is projected to substantially decrease the need for PCSK9 inhibitor treatment to achieve LDL-C targets, associated with reduced drug costs albeit with fewer prevented events.

Trends in Ezetimibe Prescriptions as Monotherapy or Fixed-Dose Combination in Germany 2012-2021.

Aims: Addition of ezetimibe to statin therapy is recommended by current guidelines when low-density lipoprotein cholesterol (LDL-C) targets are not achieved with statin monotherapy. Fixed-dose combinations (FDC) improve medication adherence and facilitate risk factor control. We assessed prescription trends of ezetimibe as monotherapy or FDC with statins. Methods: Data from the German Institute for Drug Use Evaluation (DAPI) containing dispensing data of >80% of community pharmacies were analyzed. Prescriptions over time of lipid-lowering agents at the expense of the statutory health insurance (SHI) were extrapolated to all SHI-insured persons, representing approximately 88% of the total German population. Drug utilization was expressed as defined daily doses per 1,000 SHI-insured persons per day (DID). Results: Of all lipid-lowering drug prescriptions in 2021, 91.2% were statin monotherapy. Ezetimibe was prescribed as monotherapy or FDC with statin in 4.4 and 2.9%, respectively. DID steadily increased for statin (69%) and ezetimibe (424%) monotherapies between 2012 and 2021. In contrast, statin-ezetimibe FDC prescriptions exhibited only a minor increase (29%). The proportion of statin-ezetimibe FDC among all statin prescriptions was stable over time at approximately 3%. FDC prescription rates by specialists were higher compared to general practitioners and varied considerably between geographic areas. Conclusion: Combination lipid-lowering therapy is prescribed to a minority of patients. Prescriptions of ezetimibe as monotherapy increased to a much greater extent than statin-ezetimibe FDC. Considering the low proportion of patients achieving their LDL-C target and improved adherence to FDC compared to separate pills, statin-ezetimibe FDC may be utilized to improve the management of dyslipidemia.

[Update on PCSK9 inhibition]. / PCSK9-Hemmung ­ ein Update.

Lowering of low-density lipoprotein (LDL) cholesterol represents one of the most effective interventions in cardiovascular prevention. Besides the oral treatment with statins, ezetimibe and bempedoic acid, subcutaneously administered inhibitors of proprotein convertase subtilisin-kexin type 9 (PCSK9) have been established as further cornerstones of lipid-lowering treatment. The antibodies evolocumab and alirocumab are administered subcutaneously every 2-4 weeks and lower LDL cholesterol by around 60%, independent of pre-treatment with very good tolerability. Both drugs successfully reduced cardiovascular endpoints in large outcome trials. A novel principle of PCSK9 inhibition is RNA interference, which is exploited by the novel compound inclisiran. Inclisiran is a double-stranded modified RNA molecule, which neutralizes the mRNA of PCSK9 and thus inhibits PCSK9 protein synthesis intracellularly. Inclisiran only needs to be administered every 6 months. The cardiovascular outcome trial ORION­4 is currently ongoing. In Germany, prescription of PCSK9 inhibitors is regulated by the decision of the Federal Joint Committee. Novel strategies to inhibit PCSK9 function are under development and include orally available drugs and animal experiment concepts on gene editing, which are in different states of evaluation.

[Modern lipid-lowering drugs-A means to counter the problem of undertreatment?] / Moderne Lipidsenker ­ ein Mittel gegen das Problem der Unterversorgung?

BACKGROUND: An elevated low-density lipoproteincholesterol (LDL-C) level is one of the most important modifiable cardiovascular risk factors. Despite potent combination treatment, the LDL­C target values are not achieved in many high-risk patients. OBJECTIVE: Presentation of the rationale for lowering LDL­C, the current status of lipid-lowering treatment and established and novel approaches to lower LDL­C. CURRENT DATA: Based on the large outcome trials with ezetimibe and antibodies against proprotein convertase subtilisin-kexin type 9 (PCSK9), the professional societies recommend LDL­C target values depending on the individual cardiovascular risk. For patients with manifest atherosclerosis, the LDL­C target value is < 55 mg/dL (1.4 mmol/L). The LDL­C target values are only achieved in the minority of patients. The reasons for this include a lack of awareness among treating physicians, low medication adherence, restrictions in prescriptions and intolerance. On the basis of a healthy lifestyle, statins are the cornerstone of LDL-C-lowering treatment. If LDL­C targets are not achieved, the cholesterol absorption inhibitor ezetimibe is additionally recommended. As a third step, PCSK9 antibodies are added. A novel drug to lower LDL­C is the orally available bempedoic acid, which acts on the same metabolic pathway as statins but is specifically activated in the liver and not in the skeletal muscle. Another novel drug is inclisiran, which acts as an intracellular PCSK9 inhibitor through RNA interference. Inclisiran is administered subcutaneously only every 6 months and has potential advantages regarding adherence. According to the new recommendations, active substances should be combined and fixed-dose combinations should be used early for lowering of LDL­C. CONCLUSION: Using established and novel LDL-C-lowering drugs, the recommended LDL­C target values can be achieved in the majority of patients with a high cardiovascular risk.

Gene Therapy Targeting PCSK9.

The last decades of research in cardiovascular prevention have been characterized by successful bench-to-bedside developments for the treatment of low-density lipoprotein (LDL) hypercholesterolemia. Recent examples include the inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) with monoclonal antibodies, small interfering RNA and antisense RNA drugs. The cumulative effects of LDL cholesterol on atherosclerosis make early, potent, and long-term reductions in LDL cholesterol desirable-ideally without the need of regular intake or application of medication and importantly, without side effects. Current reports show durable LDL cholesterol reductions in primates following one single treatment with PCSK9 gene or base editors. Use of the CRISPR/Cas system enables precise genome editing down to single-nucleotide changes. Provided safety and documentation of a reduction in cardiovascular events, this novel technique has the potential to fundamentally change our current concepts of cardiovascular prevention. In this review, the application of the CRISPR/Cas system is explained and the current state of in vivo approaches of PCSK9 editing is presented.

Non-statin lipid-lowering therapy over time in very-high-risk patients: effectiveness of fixed-dose statin/ezetimibe compared to separate pill combination on LDL-C.

BACKGROUND: Many patients at very-high atherosclerotic cardiovascular disease risk do not reach guideline-recommended targets for LDL-C. There is a lack of data on real-world use of non-statin lipid-lowering therapies (LLT) and little is known on the effectiveness of fixed-dose combinations (FDC). We therefore studied prescription trends in oral non-statin LLT and their effects on LDL-C. METHODS: A retrospective analysis was conducted of electronic medical records of outpatients at very-high cardiovascular risk treated by general practitioners (GPs) and cardiologists, and prescribed LLT in Germany between 2013 and 2018. RESULTS: Data from 311,242 patients were analysed. Prescriptions for high-potency statins (atorvastatin and rosuvastatin) increased from 10.4% and 25.8% of patients treated by GPs and cardiologists, respectively, in 2013, to 34.7% and 58.3% in 2018. Prescription for non-statin LLT remained stable throughout the period and low especially for GPs. Ezetimibe was the most prescribed non-statin LLT in 2018 (GPs, 76.1%; cardiologists, 92.8%). Addition of ezetimibe in patients already prescribed a statin reduced LDL-C by an additional 23.8% (32.3 ± 38.4 mg/dL), with a greater reduction with FDC [reduction 28.4% (40.0 ± 39.1 mg/dL)] as compared to separate pills [19.4% (27.5 ± 33.8 mg/dL)]; p < 0.0001. However, only a small proportion of patients reached the recommended LDL-C level of < 70 mg/dL (31.5% with FDC and 21.0% with separate pills). CONCLUSIONS: Prescription for high-potency statins increased over time. Non-statin LLT were infrequently prescribed by GPs. The reduction in LDL-C when statin and ezetimibe were prescribed in combination was considerably larger for FDC; however, a large proportion of patients still remained with uncontrolled LDL-C levels.

Familial chylomicronemia syndrome due to a heterozygous deletion of the chromosome 8 treated with the apoCIII inhibitor volanesorsen: A case report.

RATIONALE: Familial chylomicronemia syndrome is a congenital, severe form of hypertriglyceridemia associated with increased risk of acute pancreatitis. Treatment options are limited. PATIENT CONCERNS: A 52-year-old woman was referred with recurrent pancreatitis and severe hypertriglyceridemia to our lipid clinic. DIAGNOSIS: Laboratory examination showed elevated serum triglyceride concentrations of 8090 mg/dL (90 mmol/L). Lipid electrophoresis showed a type V phenotype with positive chylomicrons. Genetic investigation revealed a novel heterozygous large deletion of the lipoprotein lipase gene on chromosome 8. A familial chylomicronemia syndrome was diagnosed. Other causes of hypertriglyceridemia were excluded. INTERVENTIONS: Fibrates and diet did not lower triglyceride levels. Therefore, treatment with the apolipoprotein CIII (apoCIII) inhibitor volanesorsen was initiated. OUTCOMES: After 3 months of treatment, a 90% reduction of triglycerides was observed. ApoCIII concentrations were reduced by 90% in the total and by 61% in the chylomicron-free serum. Treatment was well tolerated with only minor local reaction after the first application. The platelet count was monitored weekly and did not decrease <150 cells/µL. LESSONS: This case report shows that inhibition of apoCIII potently reduces serum triglycerides in patients with heterozygous monogenetic deletion of the lipoprotein lipase gene. Follow-up will show the effect on recurrent episodes of pancreatitis.

Obesity-An Update on the Basic Pathophysiology and Review of Recent Therapeutic Advances.

Obesity represents a major public health problem with a prevalence increasing at an alarming rate worldwide. Continuous intensive efforts to elucidate the complex pathophysiology and improve clinical management have led to a better understanding of biomolecules like gut hormones, antagonists of orexigenic signals, stimulants of fat utilization, and/or inhibitors of fat absorption. In this article, we will review the pathophysiology and pharmacotherapy of obesity including intersection points to the new generation of antidiabetic drugs. We provide insight into the effectiveness of currently approved anti-obesity drugs and other therapeutic avenues that can be explored.

Cutaneous manifestations in familial hypercholesterolaemia.

BACKGROUND AND AIMS: Familial hypercholesterolaemia (FH) is associated with high cardiovascular risk and underdiagnosed. Cutaneous manifestations are traditionally used as a major criterion of FH. They are included in the Dutch Lipid Clinic Network or Simon Broome registry criteria. The objective of this study was to evaluate cutaneous manifestations in contemporary FH patients. METHODS: We prospectively analysed the clinical presentation of FH patients referred to a University lipid clinic and validated these data in the German FH registry CaRe High. RESULTS: Physical examination revealed that only 14.4% of the FH patients in the lipid clinic cohort (n = 223) showed cutaneous manifestations. An arcus cornealis was present in 0.9%, xanthomata in 1.8%, and xanthelasmata in 12.1%. Xanthelasmata are not part of the clinical scores, but represented 84.4% of all cutaneous manifestations. In 42.6% (n = 95) of the patients, genetic analysis was available. A causal FH mutation was detected in 50.5%. Among carriers, 66.7% had no cutaneous manifestation, 8.3% exhibited an arcus cornealis or xanthomata, and 25.0% had xanthelasmata. In the CaRe High FH registry, data on cutaneous manifestations were available in n = 1274 patients. 3.5% had xanthomata, 5.7% an arcus cornealis, and 7.7% at least one of both; xanthelasmata were present in 10.3%. CONCLUSIONS: Cutaneous manifestations are only present in a minority of contemporary patients with FH including the subgroup with monogenic FH mutations. Although rare, the cutaneous signs have value in terms of specificity. However, the clinical characteristics shared by the majority of FH patients may be better suited for screening purposes.

General health of patients with diabetic macular edema-The LIPSIA study.

PURPOSE: Cardiovascular risk factors such as hypertension or dyslipidemia can influence the incidence and progression of diabetic retinopathy (DR) and diabetic macular edema (DME). The aim of this study is to describe the comorbidities in patients with DME. METHODS: Prospective, monocentric observational study. Patients presenting for the treatment of DME received laboratory and clinical examinations including 24-hour blood pressure measurement. RESULTS: Seventy-five consecutive patients were included in the study. The mean age was 61.0 ± 14.5 years, and 83% had type 2 diabetes. The mean body mass index (BMI) was 32.8 ± 6.0 kg/m2. Overweight (BMI ≥ 25 kg/m2) was present in 92% of all patients. HbA1c values were > 7.0% in 57%. Although 87% of the patients already received antihypertensive therapy, the blood pressure (BP) of 82% was still above the recommended target values of systolic < 140 mmHg and diastolic < 80 mmHg. An insufficient nocturnal fall of the systolic BP (< 10%, non-dipping or reverse dipping) was observed in 62%. In 83% of the patients the glomerular filtration rate was ≤ 90 ml/min/1.73m2. Despite 65% of the cohort already receiving lipid-lowering therapy, LDL cholesterol was above the target value of 1.4 mmol/l in 93%. All patients had at least one cardiovascular risk factor in addition to diabetes (overweight, hypertension, insufficient nocturnal BP fall, dyslipidemia, or renal dysfunction) and 86% had ≥ 3 risk factors. CONCLUSION: DME patients are characterized by highly prevalent cardiovascular risk factors that are poorly controlled. These comorbidities reduce the prognosis and negatively influence existing DR and DME. The data reveal an important opportunity for improving patient care by interaction of the ophthalmologist with the general practitioner and internal specialists for the detection and treatment of these conditions.

Genetic Variation in Sodium-glucose Cotransporter 2 and Heart Failure.

Inhibition of sodium-glucose cotransporter 2 (SGLT2) represents an emerging pharmaceutical approach for the treatment of heart failure. The mechanisms by which SGLT2 inhibitors reduce the risk of heart failure are not well understood. The objective of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the SLC5A2 gene, encoding SGLT2, and heart failure, and to assess potential mediators of this association. Regression and mediation analyses were conducted with individual participant data of the UK Biobank (n = 416,737) and validated in the cardiovascular high-risk cohort of the LUdwigshafen RIsk and Cardiovascular Health study (LURIC; n = 3316). Two intronic SNPs associated with SLC5A2 expression were included in a genetic score, which was associated with lower risk of heart failure in UK Biobank (odds ratio 0.97, 95% confidence interval, 0.95-0.99, P = 0.016). This association was also present in participants without type 2 diabetes or coronary artery disease (CAD). The associations of the genetic score with HbA1c, high-density lipoprotein cholesterol, uric acid, systolic blood pressure, waist circumference, and body composition mediated 35% of the effect of the score on heart failure risk. No associations of the genetic SGLT2 score with atherosclerotic cardiovascular disease outcomes or markers of volume status were observed, which was confirmed in the LURIC study. Variations in the gene encoding SGLT2 were associated with the risk of prevalent or incident heart failure. This association was mediated by several mechanisms and did not depend on the presence of type 2 diabetes or previous CAD events.

PCSK9 Inhibition: Insights From Clinical Trials and Future Prospects.

In 2003, clinical observations led to the discovery of the involvement of proprotein convertase subtilisin/kexin type 9 (PCSK9) in lipid metabolism. Functional studies demonstrated that PCSK9 binds to the low-density lipoprotein (LDL) receptor directing it to its lysosomal degradation. Therefore, carriers of gain-of-function mutations in PCSK9 exhibit decreased expression of LDL receptors on the hepatocyte surface and have higher LDL cholesterol (LDL-C) levels. On the contrary, loss-of-function mutations in PCSK9 are associated with low LDL-C concentrations and significantly reduced lifetime risk of cardiovascular disease. These insights motivated the search for strategies to pharmacologically inhibit PCSK9. In an exemplary rapid development, fully human monoclonal antibodies against PCSK9 were developed and found to effectively reduce LDL-C. Administered subcutaneously every 2-4 weeks, the PCSK9 antibodies evolocumab and alirocumab reduce LDL-C by up to 60% in a broad range of populations either as monotherapy or in addition to statins. Two large cardiovascular outcome trials involving a total of ∼46,000 cardiovascular high-risk patients on guideline-recommended lipid-lowering therapy showed that treatment with evolocumab and alirocumab led to a relative reduction of cardiovascular risk by 15% after 2.2 and 2.8 years of treatment, respectively. These findings expanded the armamentarium of pharmacological approaches to address residual cardiovascular risk associated with LDL-C. Furthermore, the unprecedented low LDL-C concentrations achieved (e.g., 30 mg/dL in the FOURIER study) suggest that the relationship between LDL-C and cardiovascular risk is without a lower threshold, and without associated adverse events during the timeframe of the studies. The side effect profile of PCSK9 antibodies is favorable with few patients exhibiting injection-site reactions. Currently, the access to PCSK9 antibodies is limited by high treatment costs. The development of novel approaches to inhibit PCSK9 such as the use of small interfering RNA to inhibit PCSK9 synthesis seems promising and may soon become available.

Targeting RNA With Antisense Oligonucleotides and Small Interfering RNA: JACC State-of-the-Art Review.

There is an unmet clinical need to reduce residual cardiovascular risk attributable to apolipoprotein B-containing lipoproteins, particularly low-density lipoprotein and remnant particles. Pharmacological targeting of messenger RNA represents an emerging, innovative approach. Two major classes of agents have been developed-antisense oligonucleotides and small interfering RNA. Early problems with their use have been overcome by conjugation with N-acetylgalactosamine, an adduct that targets their delivery to the primary site of action in the liver. Using these agents to inhibit the translation of key regulatory proteins such as PCSK9, apolipoprotein CIII, apolipoprotein(a), and angiopoietin-like 3 has been shown to be effective in attenuating dyslipidemic states. Cardiovascular outcome trials with N-acetylgalactosamine-conjugated RNA-targeting drugs are ongoing. The advantages of these agents include long dosing intervals of up to 6 months and the potential to regulate the abundance of any disease-related protein. Long-term safety has yet to be demonstrated in large-scale clinical trials.

Apolipoprotein CIII predicts cardiovascular events in patients with coronary artery disease: a prospective observational study.

BACKGROUND: Apolipoprotein CIII (apoCIII) is associated with triglyceride-rich lipoprotein metabolism and has emerged as independent marker for risk of cardiovascular disease. The objective was to test whether apoCIII is regulated postprandially and whether apoCIII concentrations in native and chylomicron-free serum predict future cardiovascular events in patients with stable coronary artery disease (CAD). METHODS: ApoCIII concentrations were measured in native and chylomicron-free serum in the fasting state and after a standardized oral fat load test in 195 patients with stable CAD. Clinical follow-up was 48 months. Chylomicron-free serum was prepared by ultracentrifugation (18,000 rpm, 3 h). The log-rank test and Cox regression analyses were used to investigate the association of apoCIII with recurrent cardiovascular events. RESULTS: Of the 195 patients included, 92 had a cardiovascular event, and 103 did not. 97% were treated with a statin. No significant changes in apoCIII concentration were observed after the oral fat load test. The apoCIII concentration was associated with event-free survival independent of conventional risk factors. This association reached statistical significance only for apoCIII concentration measured in chylomicron-free serum (hazard ratio [95% confidence interval] for apoCIII above the mean: postprandial: 1.67 (1.06-2.29), P = 0.028, fasting: 2.09 (1.32-3.32), P = 0.002), but not for apoCIII concentration measured in native serum (postprandial: 1.47 [0.89-2.43], P = 0.133, fasting: 1.56 [0.95-2.58], P = 0.081). The effects were independent of other risk factors. CONCLUSIONS: ApoCIII concentrations in chylomicron-free serum are independently associated with event-free survival in patients with CAD both in fasting and postprandial state. This findings support considering apoCIII for risk assessment and attempting to test the hypothesis that lowering apoCIII reduces residual cardiovascular risk. TAKE HOME MESSAGE: Apolipoprotein CIII concentration measured in chylomicron-free serum predicts recurrent cardiovascular events in patients with stable coronary artery disease. TRIAL REGISTRATION: The trial which included the participants of this study was registered at https://clinicaltrials.gov (NCT00628524) on March 5, 2008.