LDL lowering effect of PCSK9 inhibition is reduced in women

Proprotein convertase subtilisin/kexin type 9-inhibition across different patient populations

PURPOSE OF REVIEW

Monoclonal antibodies (mAb) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) have been established in cardiovascular risk prevention. The purpose of this review is to summarize the effects of PCSK9 inhibitors across different patient populations.

RECENT FINDINGS

Long-term data on the use of evolocumab and alirocumab shows persisting low- density lipoprotein cholesterol (LDL-C) lowering and good tolerability. PCSK9 inhibitors are effective and safe in both sexes, in pediatric patients as well as in the elderly. Initiation of PCSK9 mAb during acute myocardial infarction is safe and leads to beneficial morphological plaque changes. The PCSK9 inhibitors evolocumab, alirocumab and inclisiran lower LDL-C in patients with heterozygous familial hypercholesterolemia (FH), while the response of patients with homozygous FH is heterogeneous. New areas of application beyond lipid lowering are currently investigated.

SUMMARY

PCSK9 inhibitors are safe, well tolerated, and effective in primary and secondary prevention in a wide range of patient populations.

Effectiveness and safety of alirocumab and evolocumab for hypercholesterolemia in a population with high cardiovascular risk

BACKGROUND AND AIMS

The criteria for the use of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) more restrictive than those approved were established in Catalonia by the Health System (CatSalut) to improve their efficiency, with different LDL-C values from which to start treatment according to risk factors. The aim of the study is to analyse adherence to these criteria and results.

METHODS

A retrospective study of patients treated with PCSK9i at Vall d'Hebron University Hospital between 2016 and 2021 was performed using data from the Registry of Patients and Treatments and medical records. The degree of agreement with the CatSalut criteria, LDL-C-responders (decrease ≥30%), cardiovascular events and discontinuations were analysed.

RESULTS

A total of 193 patients treated with PCSK9i were followed for a median of 27 months (IQR 23). The median age was 61 (IQR 15); 62.7% were men. Seventy percent of the patients had non-familial hypercholesterolemia. Treatment was for secondary prevention of cardiovascular disease in 82.4% of cases. The median LDL-C decreased from 139 (IQR 52) to 59 (IQR 45) mg/dL. The percentage of LDL-C reduction was 61.0% (IQR 30). In 72.5% of patients, all CatSalut criteria for starting treatment were met. The rate of responders was 85.4%. During follow-up, 19 patients (9.8%) had a cardiovascular event, and 15 (7.7%) discontinued treatment, in two cases due to toxicity.

CONCLUSION

PCSK9i were used according to CatSalut criteria in three out of four cases. In this high-risk population, incidence of cardiovascular events was similar to that in clinical trials.

Lipoprotein Metabolism, Dyslipidemia, and Lipid-Lowering Therapy in Women: A Comprehensive Review

Lipid-lowering therapy (LLT) is a cornerstone of atherosclerotic cardiovascular disease prevention. Although LLT might lead to different reductions in low-density lipoprotein cholesterol (LDL-C) levels in women and men, LLT diminishes cardiovascular risk equally effectively in both sexes. Despite similar LLT efficacy, the use of high-intensity statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 inhibitors is lower in women compared to men. Women achieve the guideline-recommended LDL-C levels less often than men. Greater cholesterol burden is particularly prominent in women with familial hypercholesterolemia. In clinical practice, women and men with dyslipidemia present with different cardiovascular risk profiles and disease manifestations. The concentrations of LDL-C, lipoprotein(a), and other blood lipids differ between women and men over a lifetime. Dissimilar levels of LLT target molecules partially result from sex-specific hormonal and genetic determinants of lipoprotein metabolism. Hence, to evaluate a potential need for sex-specific LLT, this comprehensive review (i) describes the impact of sex on lipoprotein metabolism and lipid profile, (ii) highlights sex differences in cardiovascular risk among patients with dyslipidemia, (iii) presents recent, up-to-date clinical trial and real-world data on LLT efficacy and safety in women, and (iv) discusses the diverse medical needs of women and men with dyslipidemia and increased cardiovascular risk.

Sex and statin-related genetic associations at the PCSK9 gene locus: results of genome-wide association meta-analysis

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key player of lipid metabolism with higher plasma levels in women throughout their life. Statin treatment affects PCSK9 levels also showing evidence of sex-differential effects. It remains unclear whether these differences can be explained by genetics.

METHODS

We performed genome-wide association meta-analyses (GWAS) of PCSK9 levels stratified for sex and statin treatment in six independent studies of Europeans (8936 women/11,080 men respectively 14,825 statin-free/5191 statin-treated individuals). Loci associated in one of the strata were tested for statin- and sex-interactions considering all independent signals per locus. Independent variants at the PCSK9 gene locus were then used in a stratified Mendelian Randomization analysis (cis-MR) of PCSK9 effects on low-density lipoprotein cholesterol (LDL-C) levels to detect differences of causal effects between the subgroups.

RESULTS

We identified 11 loci associated with PCSK9 in at least one stratified subgroup (p < 1.0 × 10-6), including the PCSK9 gene locus and five other lipid loci: APOB, TM6SF2, FADS1/FADS2, JMJD1C, and HP/HPR. The interaction analysis revealed eight loci with sex- and/or statin-interactions. At the PCSK9 gene locus, there were four independent signals, one with a significant sex-interaction showing stronger effects in men (rs693668). Regarding statin treatment, there were two significant interactions in PCSK9 missense mutations: rs11591147 had stronger effects in statin-free individuals, and rs11583680 had stronger effects in statin-treated individuals. Besides replicating known loci, we detected two novel genome-wide significant associations: one for statin-treated individuals at 6q11.1 (within KHDRBS2) and one for males at 12q24.22 (near KSR2/NOS1), both with significant interactions. In the MR of PCSK9 on LDL-C, we observed significant causal estimates within all subgroups, but significantly stronger causal effects in statin-free subjects compared to statin-treated individuals.

CONCLUSIONS

We performed the first double-stratified GWAS of PCSK9 levels and identified multiple biologically plausible loci with genetic interaction effects. Our results indicate that the observed sexual dimorphism of PCSK9 and its statin-related interactions have a genetic basis. Significant differences in the causal relationship between PCSK9 and LDL-C suggest sex-specific dosages of PCSK9 inhibitors.

The impact of SLCO1B1 rs4149056 on LDL-C target achievement after lipid lowering therapy optimization in men and women with familial hypercholesterolemia

Background and aims

FH women are less likely to receive intensive statin treatment and to obtain a 50% reduction of LDL-C from baseline compared to men with FH. SLCO1B1 rs4149056 might influence statin therapy compliance and thus LDL-C target achievement. Our aim was to evaluate the impact of SLCO1B1 rs4149056 on LDL-C target achievement after lipid lowering therapy (LLT) optimization in men and women with FH.

Methods

This was a retrospective observational study involving 412 FH subjects with a probable or defined clinical diagnosis of FH who had had genetic analysis from June 2016 to September 2022. Biochemical analysis was obtained from all subjects at baseline and at the last follow-up after LLT optimization.

Results

After LLT optimization the percentage of FH subjects on high-intensity statins decreased from the M/SLCO1B1- group to the W/SLCO1B1+ group and the same was found in LDL-C target distribution (for both p for trend < 0.01). The prevalence of SASE fear increased from the M/SLCO1B1- group to the W/SLCO1B1+ group and the same was observed in reported myalgia distribution (for both p for trend < 0.01). Logistic regression analysis showed that the W/SCLO1B1-, M/SCLO1B1+ and W/SCLO1B1+ groups were inversely associated with LDL-C target achievement (p for trend < 0.001) and the W/SCLO1B1+ group exhibited the strongest association.

Conclusion

A low prevalence of FH women with SLCO1B1 rs4149056 were on high intensity statins and they rarely achieved LDL-C target. The genotype effect of SLCO1B1 rs4149056 could be more pronounced in FH women than men.

Addressing Ancestry and Sex Bias in Pharmacogenomics

The association of an individual's genetic makeup with their response to drugs is referred to as pharmacogenomics. By understanding the relationship between genetic variants and drug efficacy or toxicity, we are able to optimize pharmacological therapy according to an individual's genotype. Pharmacogenomics research has historically suffered from bias and underrepresentation of people from certain ancestry groups and of the female sex. These biases can arise from factors such as drugs and indications studied, selection of study participants, and methods used to collect and analyze data. To examine the representation of biogeographical populations in pharmacogenomic data sets, we describe individuals involved in gene-drug response studies from PharmGKB, a leading repository of drug-gene annotations, and showcaseCYP2D6, a gene that metabolizes approximately 25% of all prescribed drugs. We also show how the historical underrepresentation of females in clinical trials has led to significantly more adverse drug reactions in females than in males.

Atherosclerotic Cardiovascular Disease in Women: Providing Protection With Lipid-altering Agents

PURPOSE

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death in women, yet it remains underdiagnosed, undertreated, and understudied in women compared with men. Although estrogen has provided observational evidence of cardioprotection, randomized controlled trials using hormone replacement therapy have generally produced unfavorable results.

METHODS

For this narrative review, a literature search was performed using the key words cardiovascular disease, women, and dyslipidemia in PubMed and Google Scholar with no date limitations. References within each article were also reviewed for additional relevant articles.

FINDINGS

Sex-specific risk factors and underrecognized conditions more predominant in women elevate ASCVD risk, creating further clinical challenges, such as the need for accurate risk stratification, compared with in men. Dyslipidemia frequently manifests or worsens during the menopausal transition. Therefore, identification during midlife and implementing lipid-lowering strategies to reduce ASCVD risk is imperative. Women have historically been poorly represented in cardiovascular (CV) outcome trials. However, more recent studies and meta-analyses have indicated that lipid-lowering therapies are equally effective in women and produce similar reductions in CV events and total mortality. Major cholesterol guidelines address many of the challenges that clinicians face when assessing ASCVD risk in women. Key points specific to women include obtaining a detailed history of pregnancy-related conditions, identification of common autoimmune disorders associated with systemic inflammation, and use of 10-year ASCVD risk calculators and imaging modalities (coronary artery calcium) to optimize ASCVD assessment. In terms of treatment, similar to men, women with existing ASCVD or high-risk primary prevention patients should be treated aggressively to achieve ≥50% LDL-C reductions and/or LDL-C goals as low as <55 mg/dL. Appropriate lipid-lowering therapies include high-intensity statins with or without ezetimibe and proprotein convertase subtilisin kexin/type 9 inhibitors. Women with lower ASCVD risk may be considered for low- to moderate-intensity statin therapy (approximately 30%-50% LDL-C reduction). All women, regardless of ASCVD risk category, should implement therapeutic lifestyle changes, which improve many common age-related cardiometabolic conditions.

IMPLICATIONS

Although ASCVD and current risk factor trends in women are concerning, numerous evidence-based approaches are available to protect women with ASCVD risk from life-changing CV events.

A Review of Low-Density Lipoprotein-Lowering Diets in the Age of Anti-Sense Technology

This narrative review discusses an important issue, the primary role of diet in reducing low-density lipoprotein cholesterol (LDLc) concentrations in polygenic hypercholesterolemia. Two effective drugs, statins, and ezetimibe, that lower LDLc > 20% are relatively inexpensive and potential competitors to strict dieting. Biochemical and genomic studies have shown that proprotein convertase subtilisin kexin type 9 (PCSK9) plays an important role in low-density lipoprotein (LDL) and lipid metabolism. Clinical trials have demonstrated that inhibitory monoclonal antibodies of PCSK9 dose-dependently lower LDLc up to 60%, with evidence of both regression and stabilization of coronary atherosclerosis and a reduction in cardiovascular risk. Recent approaches using RNA interference to achieve PCSK9 inhibition are currently undergoing clinical evaluation. The latter presents an attractive option of twice-yearly injections. They are, however, currently expensive and unsuitable for moderate hypercholesterolemia, which is largely due to inappropriate patterns of eating. The best dietary approach, the substitution of saturated fatty acids by polyunsaturated fatty acids at 5% energy, yields > 10% lowering of LDLc. Foods such as nuts and brans, especially within a prudent, plant-based diet low in saturates complemented by supplements such as phytosterols, have the potential to reduce LDLc further. A combination of such foods has been shown to lower LDLc by 20%. A nutritional approach requires backing from industry to develop and market LDLc-lowering products before pharmacology replaces the diet option. Energetic support from health professionals is vital.

Treatment with Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors (PCSK9i): Current Evidence for Expanding the Paradigm?

Background: Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) are low-density lipoprotein cholesterol (LDL-C)-lowering drugs that play a critical role in lipoprotein clearance and metabolism. PCSK9i are used in patients with familial hypercholesterolemia and for the secondary prevention of acute cardiovascular events in patients with atherosclerotic cardiovascular disease (CVD). Methods: We focused on the literature from 2015, the year of approval of the PCSK9 monoclonal antibodies, to the present on the use of PCSK9i not only in the lipid field but also by evaluating their effects on metabolic factors. Results: PCSK9 inhibits cholesterol efflux from macrophages and contributes to the formation of macrophage foam cells. PCSK9 has the ability to bind to Toll-like receptors, thus mediating the inflammatory response and binding to scavenger receptor B/cluster of differentiation 36. PCSK9i lower the entire spectrum of apolipoprotein B-100 containing lipoproteins (LDL, very LDLs, intermediate-density lipoproteins, and lipoprotein[a]) in high CVD-risk patients. Moreover, PCSK9 inhibitors are neutral on risk for new-onset diabetes mellitus and might have a beneficial impact on the development of nonalcoholic fatty liver disease by improving lipid and inflammatory biomarker profiles, steatosis biomarkers such as the triglyceride-glucose index, and hepatic steatosis index, although there are no comprehensive studies with long-term follow-up studies. Conclusion: The discovery of PCSK9i has opened a new era in therapeutic management in patients with hypercholesterolemia and high cardiovascular risk. Increasingly, there has been mounting scientific and clinical evidence supporting the safety and tolerability of PCSK9i.