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

Evolocumab effectiveness in the real-world setting: Austrian data from the pan-European observational HEYMANS study

BACKGROUND

This real-world study examined clinical characteristics and dyslipidemia management among patients initiating evolocumab across 12 European countries. Austrian data are reported.

METHODS

Data of consenting adults were collected for ≤ 6 months prior to evolocumab initiation (baseline) and ≤ 30 months post-initiation. Patient characteristics, lipid lowering therapy (LLT, i.e. statin and/or ezetimibe) and lipid values were collected from medical records.

RESULTS

In Austria, 363 patients were enrolled. At baseline, 52% of patients initiated evolocumab without background LLT; the median (Q1, Q3) initial low-density lipoprotein cholesterol (LDL-C) level was 142 (111, 187) mg/dL. Within 3 months of evolocumab treatment, median LDL‑C decreased by 59% to 58 (37, 91) mg/dL. This reduction was maintained over time, despite consistently infrequent use of background LLT. LDL-C < 55 mg/dL was attained by 65% of patients (76% with, 55% without background LLT). Evolocumab persistence was ≥ 90% at month 12 and month 30.

CONCLUSION

In Austria, patients were initiated on evolocumab at LDL‑C levels almost 3‑times higher than the guideline-recommended clinical goal (< 55 mg/dL). Persistence with evolocumab was very high. Evolocumab led to a rapid and sustained LDL‑C reduction with 65% attaining the LDL‑C goal. Patients using evolocumab in combination with statins and/or ezetimibe were more likely to attain their LDL‑C goal and thus decrease cardiovascular risk.

Role of proprotein convertase subtilisin/kexin type 9 (PCSK9) in diabetic complications

Cardiovascular disease (CVD) complications have remained a major cause of death among patients with diabetes. Hence, there is a need for effective therapeutics against diabetes-induced CVD complications. Since its discovery, proprotein convertase subtilisin/kexin type 9 (PCSK9) has been reported to be involved in the pathology of various CVDs, with studies showing a positive association between plasma levels of PCSK9, hyperglycemia, and dyslipidemia. PCSK9 regulates lipid homeostasis by interacting with low-density lipoprotein receptors (LDLRs) present in hepatocytes and subsequently induces LDLR degradation via receptor-mediated endocytosis, thereby reducing LDL uptake from circulation. In addition, PCSK9 also induces pro-inflammatory cytokine expression and apoptotic cell death in diabetic-CVD. Furthermore, therapies designed to inhibit PCSK9 effectively reduces diabetic dyslipidemia with clinical studies reporting reduced cardiovascular events in patients with diabetes and no significant adverse effect on glycemic controls. In this review, we discuss the role of PCSK9 in the pathogenesis of diabetes-induced CVD and the potential mechanisms by which PCSK9 inhibition reduces cardiovascular events in diabetic patients.

Long-term persistence with evolocumab treatment and sustained reductions in LDL-cholesterol levels over 30 months: Final results from the European observational HEYMANS study

BACKGROUND AND AIMS

Variability in low-density lipoprotein-cholesterol (LDL-C) level control at a population level is associated with poor cardiovascular outcomes. Limited data exist on LDL-C level variability or long-term persistence with the monoclonal antibody evolocumab in routine clinical practice. Using data from the HEYMANS registry, this analysis aimed to assess evolocumab persistence and discontinuation over 30 months of evolocumab treatment and to evaluate at a population level the variability in LDL-C level reductions during the study period.

METHODS

HEYMANS was a prospective registry of adults initiating evolocumab in routine clinical practice in 12 European countries. Data were collected for up to and including 6 months before evolocumab initiation and up to 30 months after. Evolocumab discontinuation was analysed for two time periods: 0-12 months and 12-30 months.

RESULTS

In total, 1951 patients were included in the study. The median reduction in LDL-C levels was 58% within 3 months after evolocumab initiation; this reduction was maintained over 30 months. More than 90% of patients continued receiving evolocumab at 12 months and 30 months of follow-up. Of patients with an LDL-C level measurement during follow-up, approximately 85% achieved a ≥30% reduction from baseline at each follow-up visit and approximately 60% achieved a ≥50% reduction.

CONCLUSIONS

Evolocumab therapy was associated with sustained LDL-C level reductions up to 30 months, and persistence with evolocumab remained high, both at 12 and 30 months. Expanding the use of monoclonal antibodies such as evolocumab could provide improvements in LDL-C level control at a population level in European clinical practice.

Triglyceride and Triglyceride-Rich Lipoproteins in Atherosclerosis

Cardiovascular disease (CVD) is still the leading cause of death globally, and atherosclerosis is the main pathological basis of CVDs. Low-density lipoprotein cholesterol (LDL-C) is a strong causal factor of atherosclerosis. However, the first-line lipid-lowering drugs, statins, only reduce approximately 30% of the CVD risk. Of note, atherosclerotic CVD (ASCVD) cannot be eliminated in a great number of patients even their LDL-C levels meet the recommended clinical goals. Previously, whether the elevated plasma level of triglyceride is causally associated with ASCVD has been controversial. Recent genetic and epidemiological studies have demonstrated that triglyceride and triglyceride-rich lipoprotein (TGRL) are the main causal risk factors of the residual ASCVD. TGRLs and their metabolites can promote atherosclerosis via modulating inflammation, oxidative stress, and formation of foam cells. In this article, we will make a short review of TG and TGRL metabolism, display evidence of association between TG and ASCVD, summarize the atherogenic factors of TGRLs and their metabolites, and discuss the current findings and advances in TG-lowering therapies. This review provides information useful for the researchers in the field of CVD as well as for pharmacologists and clinicians.

PCSK9: A Multi-Faceted Protein That Is Involved in Cardiovascular Biology

Pro-protein convertase subtilisin/kexin type 9 (PCSK9) is secreted mostly by hepatocytes and to a lesser extent by the intestine, pancreas, kidney, adipose tissue, and vascular cells. PCSK9 has been known to interact with the low-density lipoprotein receptor (LDLR) and chaperones the receptor to its degradation. In this manner, targeting PCSK9 is a novel attractive approach to reduce hyperlipidaemia and the risk for cardiovascular diseases. Recently, it has been recognised that the effects of PCSK9 in relation to cardiovascular complications are not only LDLR related, but that various LDLR-independent pathways and processes are also influenced. In this review, the various LDLR dependent and especially independent effects of PCSK9 on the cardiovascular system are discussed, followed by an overview of related PCSK9-polymorphisms and currently available and future therapeutic approaches to manipulate PCSK9 expression.

Monocyte-derived alveolar macrophage apolipoprotein E participates in pulmonary fibrosis resolution

Recent studies have presented compelling evidence that it is not tissue-resident, but rather monocyte-derived alveolar macrophages (TR-AMs and Mo-AMs, respectively) that are essential to development of experimental lung fibrosis. However, whether apolipoprotein E (ApoE), which is produced abundantly by Mo-AMs in the lung, plays a role in the pathogenesis is unclear. In this study, we found that pulmonary ApoE was almost exclusively produced by Mo-AMs in mice with bleomycin-induced lung fibrosis. We showed that, although ApoE was not necessary for developing maximal fibrosis in bleomycin-injured lung, it was required for the resolution of this pathology. We found that ApoE directly bound to Collagen I and mediated Collagen I phagocytosis in vitro and in vivo, and this process was dependent on low-density lipoprotein receptor-related protein 1 (LPR1). Furthermore, interference of ApoE/LRP1 interaction impaired the resolution of lung fibrosis in bleomycin-treated WT mice. In contrast, supplementation of ApoE promoted this process in ApoE-/- animals. In conclusion, Mo-AM-derived ApoE is beneficial to the resolution of lung fibrosis, supporting the notion that Mo-AMs may have distinct functions in different phases of lung fibrogenesis. The findings also suggest a potentially novel therapeutic target for treating lung fibrosis, to which effective remedies remain scarce.