Proprotein convertase subtilisin/kexin type 9 inhibitors in peripheral artery disease: A review of efficacy, safety, and outcomes

Peripheral artery disease (PAD) is a common condition characterized by atherosclerosis in the peripheral arteries, associated with concomitant coronary and cerebrovascular diseases. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are a class of drugs that have shown potential in hypercholesterolemic patients. This review focuses on the efficacy, safety, and clinical outcomes of PCSK9 inhibitors in PAD based on the literature indexed by PubMed. Trials such as FOURIER and ODYSSEY demonstrate the efficacy of evolocumab and alirocumab in reducing cardiovascular events, offering a potential treatment option for PAD patients. Safety evaluations from trials show few adverse events, most of which are injection-site reactions, indicating the overall safety profile of PCSK9 inhibitors. Clinical outcomes show a reduction in cardiovascular events, ischemic strokes, and major adverse limb events. However, despite these positive findings, PCSK9 inhibitors are still underutilized in clinical practice, possibly due to a lack of awareness among care providers and cost concerns. Further research is needed to establish the long-term effects and cost-effectiveness of PCSK9 inhibitors in PAD patients.

The real-world data of lipid-lowering treatment in patients with peripheral artery disease and its association with severity of disease

BACKGROUND

The risk of coronary artery disease in peripheral arterial disease (PAD) is high, life prognosis is poor, and lipid-lowering treatment with statins has been reported to improve prognosis. In clinical practice, however, hypolipidemia is more common in patients with severe PAD and statin prescription rates appear to be low, but specific data are scarce in Japan. Therefore, we conducted this cross-sectional study in collaboration with other centers of vascular surgery to determine the rate of statin prescriptions for PAD patients in real-world practice, the rate of achievement of low-density lipoprotein (LDL) cholesterol control targets, and whether statin non-use is a determinant factor of critical limb ischemia (CLI).

METHODS

A total of 246 PAD patients (97 with CLI) from 5 sites were included in this study. Medical history and blood test data were obtained from medical records and interviews with patients, and were compared between CLI and non-CLI patients.

RESULTS

Statin prescription rate was only 34 %. The overall LDL cholesterol control target rate was 46 % of CLI cases and 51 % of non-CLI cases, according to the lipid management criteria of the Japanese Society for Atherosclerosis 2022 guidelines. Patients in the CLI group had a lower mean body mass index and lower LDL cholesterol levels than those in the non-CLI group, suggesting that these factors were responsible for the lower statin prescription rate. However, multivariate analysis revealed that statin non-use was one of the determinants of CLI.

CONCLUSIONS

Statin prescription rates for PAD patients were low in real-world practice settings in the field of vascular surgery. Since statin non-use is a determinant of CLI, there is a need to educate physicians engaged in treatment regarding lipid-lowering treatment with statins.

A Practical Guide to Understanding and Treating Peripheral Artery Disease

ABSTRACT

Peripheral arterial disease (PAD) is the third leading cause of atherosclerotic morbidity after coronary heart disease and stroke yet is widely underdiagnosed and undertreated. Treatment of risk factors such as diabetes and cigarette smoking can benefit patients with PAD. Patients should have adequate blood pressure and lipid control to decrease clinical manifestations and symptoms of PAD. Use of antithrombotic medications should be individualized to the patient depending on the presence of symptoms, revascularization, and comorbidities. All patient care providers, including physicians, pharmacists, nurse practitioners, and physician assistants, should incorporate PAD screening in their at-risk patients to improve access for appropriate earlier diagnosis, initiation of guideline directed therapy, and risk factor modification to reduce both major adverse CV and limb outcomes. The purpose of this narrative review is to provide an overview of PAD and summarize clinical trial evidence and guideline recommendations for screening and treatment to increase awareness among health care providers to ultimately have a positive impact on patient care.

Non-Coronary Atherosclerotic Arterial Disease: Where Are We Now?

Lower extremity peripheral artery and upper extremity artery disease are significant vascular conditions with distinct clinical presentations and diagnostic and therapeutic approaches. The lower extremity peripheral artery is associated with worse major adverse cardiovascular events compared with coronary artery disease, but often remains underdiagnosed and undertreated. Upper extremity artery disease encompasses a range of clinical presentations resulting from atherosclerosis and other obstructive lesions in arteries such as the subclavian artery and brachiocephalic trunk. While atherosclerosis is a common cause, non-atherosclerotic factors can also influence distal lesions. This review aims to synthesize existing knowledge on both conditions, encompassing risk factors, clinical manifestations, diagnostic modalities, and treatment options. Improved awareness and early intervention can mitigate complications and enhance patient outcomes for lower extremity peripheral artery and upper extremity artery disease.

[Update on lipid lowering therapy in peripheral artery disease]

Despite clear guideline recommendations, only about every second PAD patient is prescribed statins, women less often than men. There is an international consensus that every PAD patient should be treated with statins, as these not only lower lipids but also stabilize plaque, resulting in a prognostic benefit. Limb-related endpoints (MALE) can be reduced by 24% compared to placebo by lowering lipids. The combination of low-dose, high-potency statin with ezetimibe can be equivalent to high-dose statin monotherapy and, with better tolerability, promote therapy adherence. Statin intolerance is observed more frequently in certain risk groups but is very rare overall. Effective alternatives are bempedoic acid and PCSK9 inhibitors. About 20% of the population have severely elevated Lp(a) levels that require risk factor management beyond lipid management. A high Lp(a) concentration is associated with PAD progression as an independent risk factor for all atherosclerosis manifestations. Every adult should have an Lp(a) assessment once in their lifetime.

Statin use improves survival of patients with known or suspected lower extremity artery disease on all ankle brachial index levels

Background: Statin medication improves the prognosis of patients with lower extremity artery disease (LEAD). Research has previously focused on patients with a lowered ankle brachial index (ABI) excluding patients with a normal or elevated ankle brachial index. The aim of this study was to analyze the impact of statin use on survival and cardiovascular mortality in patients with LEAD of different severity depicted by the ABI level. Patients and methods: 4128 ABI measurements by trained and experienced nurses between 2000 and 2009 were combined with medication data from the Social Insurance Institution and causes of death data from the national causes of death registry. End of follow-up was set at the end of 2014. The data of statin use included all statin medication with the Anatomical Therapeutic Chemical (ATC) classification codes between C10AA01 and C10AA08. Results: 1956 (47.4%) patients had statin medication. Statin use was associated with improved overall survival and amputation free survival (AFS) on all ABI levels. When adjusted for age, sex and diabetes the greatest overall survival benefit from statin use was for the patients with ABI>1.3 (hazard ratio, HR: 0.67, 95% CI: 0.48-0.94, p=0.020, reference group statin non-users) and ABI 0.9-1.3 (HR: 0.78, 95% CI: 0.65-0.94, p=0.008). In propensity score matched pairs statin treatment was associated with significantly lower all-cause mortality (p<0.0001), cardiovascular mortality (p=0.034), cerebrovascular mortality (p=0.003) and embolic stroke related mortality (p=0.001) in patients with ABI >1.3 or <0.9. Overall survival benefit was significant in females with ABI<0.5 and in males across several ABI levels. Conclusions: According to our study, statins seem to improve overall and amputation free survival regardless of ABI level. Statin use was associated with lower mortality from cerebrovascular disease, overall mortality and in the propensity score matched patients with ABI<0.9 or >1.3 with cardiovascular mortality.

Gender Disparities in Aortoiliac Revascularization in Patients with Aortoiliac Occlusive Disease

BACKGROUND

Gender disparities have been previously reported in aortic aneurysm and critical limb ischemia outcomes; however, limited info is known about disparities in aortoiliac occlusive disease. We sought to characterize potential disparities in this specific population.

MATERIAL AND METHODS

Patients who underwent aortobifemoral bypass and aortic thromboendarterectomy (Current Procedural Terminology codes 35646 and 35331) between 2012 and 2019 were identified in the National Surgical Quality Improvement Program database. A binomial regression model was used to estimate gender differences in 30-day morbidity and mortality. Inverse probability weighting was used to standardize demographic and surgical characteristics.

RESULTS

We identified 1,869 patients, of which 39.8% were female and the median age was 61 years. Age, body composition, and other baseline characteristics were overall similar between genders; however, racial data were missing for 26.1% of patients. Females had a higher prevalence of preexisting chronic obstructive pulmonary disease (20.9% vs. 14.7%, prevalence difference 6.1%, P < 0.01), diabetes mellitus (25.4% vs. 19.4%, prevalence difference 6.0%, P < 0.01), and high-risk anatomical features (39.4% vs. 33.7%, prevalence difference 5.8%, P = 0.01). Preprocedural medications included a statin in only 68.2% of patients and antiplatelet agent in 76.7% of patients. Females also had a higher incidence of bleeding events when compared to males (25.2% vs. 17.5%, standardized risk difference 7.2%, P < 0.01), but were less likely to have a prolonged hospitalization greater than 10 days (18.2% vs. 20.9%, standardized risk difference -5.0%, P = 0.01). The 30-day mortality rate was not significantly different between genders (4.7% vs. 3.6%, standardized risk difference 1.2%, P = 0.25).

CONCLUSIONS

Female patients treated with aortobifemoral bypass or aortic thromboendarterectomy are more likely to have preexisting chronic obstructive pulmonary disease, diabetes mellitus, and high-risk anatomical features. Regardless of a patient's gender, there is poor adherence to preoperative medical optimization with both statins and antiplatelet agents. Female patients are more likely to have postoperative bleeding complications while males are more likely to have a prolonged hospital stay greater than 10 days. Future work could attempt to further delineate disparities using databases with longer follow-up data and seek to create protocols for reducing these observed disparities.

Role of Lipid-Lowering Therapy in Peripheral Artery Disease

Atherosclerosis is a multifactorial, lipoprotein-driven condition that leads to plaque formation within the arterial tree, leading to subsequent arterial stenosis and thrombosis that accounts for a large burden of cardiovascular morbidity and mortality globally. Atherosclerosis of the lower extremities is called peripheral artery disease and is a major cause of loss in mobility, amputation, and critical limb ischemia. Peripheral artery disease is a common condition with a gamut of clinical manifestations that affects an estimated 10 million people in the United States of America and 200 million people worldwide. The role of apolipoprotein B-containing lipoproteins, such as LDL and remnant lipoproteins in the development and progression of atherosclerosis, is well-established. The focus of this paper is to review existing data on lipid-lowering therapies in lower extremity atherosclerotic peripheral artery disease.

Presence of asymptomatic Peripheral Arterial Disease in combination with common risk factors elevates the cardiovascular risk Substantially

Background and aims

This study evaluates the risks for adverse cardiovascular (CV) events in Asymptomatic Peripheral Arterial Disease (APAD) combined with different traditional CV risk factors.

Methods

A population-based observational study of 8000 subjects, identified 559 subjects as having APAD through ankle-brachial index (ABI) measurements and questionnaires regarding limb symptoms. This cohort and subgroups classified by presence of different traditional CV risk factors at baseline were assessed for 10 years on CV outcome. The recorded endpoints were all-cause mortality, CV mortality and non-fatal CV events.

Results

Before subdividing the APAD subjects, the CV mortality incidence was 28.5 deaths per 1000 person-years as compared to 8.7 deaths for references without APAD. For subjects with hypertension at baseline the CV mortality incidence was 35.4 when combined with APAD and 11.7 without. In women with hypertension but without other risk factors, presence of APAD increased the age-adjusted Hazard Ratio (HR) for fatal and non-fatal CV events by 1.86 [CI 1.54,2.24, p < 0.001].

Conclusions

ABI measurements should be considered an important indication for aggressive multifactorial risk factor reduction in populations with any other prevalent CV risk factor. In hypertension, diabetes mellitus and a smoking history, coexisting APAD contributes significantly to the increased age-adjusted CV risk.

Identification of neolignans with PCSK9 downregulatory and LDLR upregulatory activities from Penthorum chinense and the potential in cholesterol uptake by transcriptional regulation of LDLR via SREBP2

ETHNOPHARMACOLOGICAL RELEVANCE

Penthorum chinense has been used in East Asia for the treatment of cholecystitis, infectious hepatitis, jaundice and to treat liver problems. Recent evidences provided the potential for the clinical use of P. chinense in the treatment of metabolic disease.

AIM OF THE STUDY

Based on the traditional use and recent evidences, we investigated the effects of constituents from P. chinense with modulation on proprotein convertase subtilisin/kexin type 9 (PCSK9) and low-density lipoprotein receptor (LDLR) expression, and the effect of the most active substance on cholesterol uptake, and genes relevant to lipid metabolism.

MATERIALS AND METHODS

The isolation of compounds from the BuOH-soluble extract of 80% methanol extract of P. chinense was conducted using chromatographic methods and the structures were established by interpreting spectroscopic data. Quantitative real time-PCR, and Western blot analysis were performed to monitor the regulatory activity on PCSK9 and LDLR expression. PCSK9-LDLR binding interaction was also tested. The cholesterol uptake in hepatocyte was measured using 1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate (DiI)-labeled LDL cholesterol. Additionally, gene network analysis of LDLR and responses of its target proteins were carried out to discover genes germane to the effect of active compound on HepG2 cells. Moreover, we performed protein-protein interaction analysis via String and constructed the compound target network using Cytoscape.

RESULTS

Two new neolignans and 37 known compounds were characterized from P. chinense. Of the isolated compounds, (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3), penthorin A (4) and methyl gallate (25) were found to suppress PCSK9 mRNA expression with IC₅₀ values of 5.13, 15.56 and 11.66 μM, respectively. However, all the isolated compounds were found to be inactive in PCSK9-LDLR interaction assay. Additionally, a dibenzoxepine-type lignan analog, (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3) demonstrated to upregulate LDLR mRNA and protein expression via transcriptional factor sterol regulatory element-binding protein 2 (SREBP2). Furthermore, (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3) increase the LDL-cholesterol uptake in DiI-LDL assay.

CONCLUSION

(7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3) seemed to increase potentially cholesterol uptake via the downregulation of PCSK9 and the activation of LDLR in hepatocytes. Moreover, SREBP2 was found to play an important role in regulation of PCSK9 and LDLR by (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one.