Role of Lipid-Lowering Therapy in Peripheral Artery Disease

Histological Changes in the Popliteal Artery Wall in Patients with Critical Limb Ischemia

INTRODUCTION

This prospective study aims to illustrate the histopathological arterial changes in the popliteal artery in peripheral arterial disease of the lower limbs.

MATERIAL AND METHOD

A total of 60 popliteal artery segments taken from patients who had undergone lower limb amputation were examined between April and June 2023. The degree of arterial stenosis, medial calcinosis, and the vasa vasorum changes in the arterial adventitia were quantified. The presence of risk factors for atherosclerosis was also observed.

RESULTS

Atherosclerotic plaque was found in all of the examined segments. Medial calcinosis was observed in 40 (66.6%) of the arterial segments. A positive association between the degree of arterial stenosis and the vasa vasorum changes in the arterial adventitia was also found (p = 0.025). The level of blood sugar and cholesterol were predictive factors for the severity of atherosclerosis.

CONCLUSIONS

Atherosclerosis and medial calcinosis are significant in patients who underwent lower limb amputation. Medial calcinosis causes damage to the arterial wall and leads to a reduction in responsiveness to dilator stimuli.

Cholesterol Crystal Embolization Exacerbates Critical Limb Ischemia

Chronic life-threatening ischemia (CLTI), characterized by chronic severe ischemic ulcers or gangrene in the legs with arterial occlusive disease, has a high rate of amputation and mortality. However, how lower extremity artery disease (LEAD) leads to CLTI is not fully understood yet. Here, we report a 79-year-old man with resting pain and gangrene in the left first and fifth toes for a year who had undergone repetitive endovascular treatment (EVT) that temporarily improved the ischemia. Non-obstructive general angioscopy (NOGA) revealed yellow and red floating emboli at the occluded left superficial femoral artery (SFA). Although a second EVT for the reoccluded SFA was successful, amputation of the left lower knee remained necessary because of osteomyelitis of the left heel. Cholesterol crystals (CCs) associated with innate inflammation were detected in spontaneously ruptured aortic plaques (SRAPs) via aortic screening using the NOGA, in occluded SFAs, and on the surface of the muscle cross-section of the amputated legs via a polarizing microscope. Histopathological analysis demonstrated CCs in small vessels in various stages of patchy necrosis and muscle regeneration. In this case, the process of CC embolization, such as the embolic source of CCs, occlusion in arteries, small arteries, and deposition in muscles, was confirmed in CLTI. CCs are the principal trigger of IL-6 production through the innate inflammatory response in spontaneously ruptured aortic plaques. Mechanical ischemia and chronic inflammation due to embolized CCs may cause chronic limb damage. In this case, the CC embolization might exacerbate CLTI.

Advancements in Omics and Breakthrough Gene Therapies: A Glimpse into the Future of Peripheral Artery Disease

Peripheral artery disease (PAD), a highly prevalent global disease, associates with significant morbidity and mortality in affected patients. Despite progress in endovascular and open revascularization techniques for advanced PAD, these interventions grapple with elevated rates of arterial restenosis and vein graft failure attributed to intimal hyperplasia (IH). Novel multiomics technologies, coupled with sophisticated analyses tools recently powered by advances in artificial intelligence, have enabled the study of atherosclerosis and IH with unprecedented single-cell and spatial precision. Numerous studies have pinpointed gene hubs regulating pivotal atherogenic and atheroprotective signaling pathways as potential therapeutic candidates. Leveraging advancements in viral and nonviral gene therapy (GT) platforms, gene editing technologies, and cutting-edge biomaterial reservoirs for delivery uniquely positions us to develop safe, efficient, and targeted GTs for PAD-related diseases. Gene therapies appear particularly fitting for ex vivo genetic engineering of IH-resistant vein grafts. This manuscript highlights currently available state-of-the-art multiomics approaches, explores promising GT-based candidates, and details GT delivery modalities employed by our laboratory and others to thwart mid-term vein graft failure caused by IH, as well as other PAD-related conditions. The potential clinical translation of these targeted GTs holds the promise to revolutionize PAD treatment, thereby enhancing patients' quality of life and life expectancy.

A Non-Coronary, Peripheral Arterial Atherosclerotic Disease (Carotid, Renal, Lower Limb) in Elderly Patients-A Review PART II-Pharmacological Approach for Management of Elderly Patients with Peripheral Atherosclerotic Lesions outside Coronary Territory

BACKGROUND

Aging is a key risk factor for atherosclerosis progression that is associated with increased incidence of ischemic events in supplied organs, including stroke, coronary events, limb ischemia, or renal failure. Cardiovascular disease is the leading cause of death and major disability in adults ≥ 75 years of age. Atherosclerotic occlusive disease affects everyday activity, quality of life, and it is associated with reduced life expectancy. As most multicenter randomized trials exclude elderly and very elderly patients, particularly those with severe comorbidities, physical or cognitive dysfunctions, frailty, or residence in a nursing home, there is insufficient data on the management of older patients presenting with atherosclerotic lesions outside coronary territory. This results in serious critical gaps in knowledge and a lack of guidance on the appropriate medical treatment. In addition, due to a variety of severe comorbidities in the elderly, the average daily number of pills taken by octogenarians exceeds nine. Polypharmacy frequently results in drug therapy problems related to interactions, drug toxicity, falls with injury, delirium, and non-adherence. Therefore, we have attempted to gather data on the medical treatment in patients with extra-cardiac atherosclerotic lesions indicating where there is some evidence of the management in elderly patients and where there are gaps in evidence-based medicine. Public PubMed databases were searched to review existing evidence on the effectiveness of lipid-lowering, antithrombotic, and new glucose-lowering medications in patients with extra-cardiac atherosclerotic occlusive disease.

Preventive Therapies in Peripheral Arterial Disease

Atherosclerosis, while initially deemed a bland proliferative process, is now recognized as a multifactorial-lipoprotein-mediated inflammation-driven pathway. With the rising incidence of atherosclerotic disease of the lower extremity arteries, the healthcare burden and clinical morbidity and mortality due to peripheral artery disease (PAD) are currently escalating. With a healthcare cost burden of over 21 billion USD and 200 million patients afflicted worldwide, accurate knowledge regarding the pathophysiology, presentation, and diagnosis of the disease is crucial. The role of lipoproteins and their remnants in atherosclerotic vessel occlusion and plaque formation and progression has been long established. This review paper discusses the epidemiology, pathophysiology, and presentation of PAD. PAD has been repeatedly noted to portend to poor cardiovascular and limb outcomes. We discuss major therapeutic avenues for the prevention of major cardiovascular adverse events and major limb adverse events in patients with PAD.

A Comprehensive Review of the Vascular Consequences of Diabetes in the Lower Extremities: Current Approaches to Management and Evaluation of Clinical Outcomes

Diabetes mellitus is a global health concern characterized by chronic hyperglycemia, and its vascular consequences in the lower extremities pose significant challenges for individuals living with the condition. This comprehensive review delves into the multifaceted landscape of diabetes-related vascular complications in the lower limbs, with a primary focus on current strategies for management and the evaluation of clinical outcomes. This review achieves several critical objectives by synthesizing existing knowledge and research findings. It elucidates the intricate pathophysiological mechanisms underpinning these complications, shedding light on the cellular and molecular processes involved. Additionally, it outlines clinical assessment and diagnostic strategies used to identify and stratify risk, ranging from cutting-edge imaging techniques to clinical examinations. The review comprehensively examines current management strategies, encompassing lifestyle modifications, pharmacological interventions, surgical procedures, and wound care practices. Moreover, it assesses and analyzes clinical outcomes, including limb salvage rates, amputation rates, and overall quality of life for individuals undergoing treatment. In addressing the challenges faced in managing these complications, this review aims to contribute to improved patient care. It proposes future research directions to enhance the management and outcomes of diabetes-related vascular consequences in the lower extremities.

Limb Salvage and Survival in Chronic Limb-Threatening Ischemia: The Need for a Fast-Track Team-Based Approach

Chronic limb-threatening ischemia (CLTI) represents the end-stage form of peripheral arterial disease (PAD) and is associated with a very poor prognosis and high risk of limb loss and mortality. It can be considered very similar to a terminal cancer disease, reflecting a large impact on quality of life and healthcare costs. The aim of this study is to offer an overview of the relationship between CLTI, limb salvage, and mortality, with a focus on the need of a fast-track team-based management that is a driver to achieve better survival results. This review can be useful to improve management of this growing impact disease, and to promote the standardisation of care and communication between specialist and non-specialist healthcare professionals.

Focus on Prevention: Peripheral Arterial Disease and the Central Role of the Cardiologist

Peripheral artery disease (PAD) is a manifestation of systemic atherosclerotic disease. PAD patients have a poor prognosis with an increased risk of cardiovascular (CV) events, including myocardial infarction (MI), stroke, limb ischemia and CV death; therefore, it is important to detect and treat PAD early. PAD and coronary artery disease (CAD) share a common pathogenesis and risk factors for development; therefore, cardiologists are in a unique position to screen, diagnosis and treat PAD. Moreover, PAD and CAD also share some treatment goals, including an aggressive modification of risk factors to reduce the risk of CV events. However, PAD remains an underdiagnosed and undertreated disease with medico-legal implications. As the role of cardiologists is expanding, the purpose of this review was to awaken the clinicians to the significance of PAD.

Clinical Potential of Hydrogen Sulfide in Peripheral Arterial Disease

Peripheral artery disease (PAD) affects more than 230 million people worldwide. PAD patients suffer from reduced quality of life and are at increased risk of vascular complications and all-cause mortality. Despite its prevalence, impact on quality of life and poor long-term clinical outcomes, PAD remains underdiagnosed and undertreated compared to myocardial infarction and stroke. PAD is due to a combination of macrovascular atherosclerosis and calcification, combined with microvascular rarefaction, leading to chronic peripheral ischemia. Novel therapies are needed to address the increasing incidence of PAD and its difficult long-term pharmacological and surgical management. The cysteine-derived gasotransmitter hydrogen sulfide (H₂S) has interesting vasorelaxant, cytoprotective, antioxidant and anti-inflammatory properties. In this review, we describe the current understanding of PAD pathophysiology and the remarkable benefits of H₂S against atherosclerosis, inflammation, vascular calcification, and other vasculo-protective effects.