Neo-intimal hyperplasia, diabetes and endovascular injury

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Review of Polymeric Biomimetic Small-Diameter Vascular Grafts to Tackle Intimal Hyperplasia

Small-diameter artificial vascular grafts (SDAVG) are used to bypass blood flow in arterial occlusive diseases such as coronary heart or peripheral arterial disease. However, SDAVGs are plagued by restenosis after a short while due to thrombosis and the thickening of the neointimal wall known as intimal hyperplasia (IH). The specific causes of IH have not yet been deduced; however, thrombosis formation due to bioincompatibility as well as a mismatch between the biomechanical properties of the SDAVG and the native artery has been attributed to its initiation. The main challenges that have been faced in fabricating SDAVGs are facilitating rapid re-endothelialization of the luminal surface of the SDAVG and replicating the complex viscoelastic behavior of the arteries. Recent strategies to combat IH formation have been mostly based on imitating the natural structure and function of the native artery (biomimicry). Thus, most recently, developed grafts contain a multilayered structure with a designated function for each layer. This paper reviews the current polymeric, biomimetic SDAVGs in preventing the formation of IH. The materials used in fabrication, challenges, and strategies employed to tackle IH are summarized and discussed, and we focus on the multilayered structure of current SDAVGs. Additionally, the future aspects in this area are pointed out for researchers to consider in their endeavor.

Iliac occlusion due to covered stent deformation following abdominal massages

Extrinsic compression is a potential cause of stent failure. We have described the case of a 65-year-old paraplegic patient with acute right leg ischemia. His medical history was relevant for aortobifemoral bypass, followed by kissing covered stent reconstruction of a proximal anastomotic false aneurysm. The computed tomography scan showed collapse of the right iliac covered stent with ipsilateral iliofemoral graft thrombosis and partial collapse of the left iliac covered stent. He underwent emergent right iliac limb open thrombectomy and redo covered stent relining. The cause of compression was found to be daily deep abdominal massages for intestinal evacuation. The endovascular device should be tailored to the patient's particularities.

M6A methylation-mediated elevation of SM22α inhibits the proliferation and migration of vascular smooth muscle cells and ameliorates intimal hyperplasia in type 2 diabetes mellitus

Abnormal proliferation of vascular smooth muscle cells (VSMCs) induced by insulin resistance facilitates intimal hyperplasia of type 2 diabetes mellitus (T2DM) and N6-methyladenosine (m⁶A) methylation modification mediates the VSMC proliferation. This study aimed to reveal the m⁶A methylation modification regulatory mechanism. In this study, m⁶A demethylase FTO was elevated in insulin-treated VSMCs and T2DM mice with intimal injury. Functionally, FTO knockdown elevated m⁶A methylation level and further restrained VSMC proliferation and migration induced by insulin. Mechanistically, FTO knockdown elevated Smooth muscle 22 alpha (SM22α) expression and m⁶A-binding protein IGF2BP2 enhanced SM22α mRNA stability by recognizing and binding to m⁶A methylation modified mRNA. In vivo studies confirmed that the elevated m⁶A modification level of SM22α mRNA mitigated intimal hyperplasia in T2DM mice. Conclusively, m⁶A methylation-mediated elevation of SM22α restrained VSMC proliferation and migration and ameliorated intimal hyperplasia in T2DM.

PARP1 deficiency protects against hyperglycemia-induced neointimal hyperplasia by upregulating TFPI2 activity in diabetic mice

Diabetes mellitus (DM) promotes neointimal hyperplasia, characterized by dysregulated proliferation and accumulation of vascular smooth muscle cells (VSMCs), leading to occlusive disorders, such as atherosclerosis and stenosis. Poly (ADP-ribose) polymerase 1 (PARP1), reported as a crucial mediator in tumor proliferation and transformation, has a pivotal role in DM. Nonetheless, the function and potential mechanism of PARP1 in diabetic neointimal hyperplasia remain unclear. In this study, we constructed PARP1 conventional knockout (PARP1^−/−) mice, and ligation of the left common carotid artery was performed to induce neointimal hyperplasia in Type I diabetes mellitus (T1DM) mouse models. PARP1 expression in the aorta arteries of T1DM mice increased significantly and genetic deletion of PARP1 showed an inhibitory effect on the neointimal hyperplasia. Furthermore, our results revealed that PARP1 enhanced diabetic neointimal hyperplasia via downregulating tissue factor pathway inhibitor (TFPI2), a suppressor of vascular smooth muscle cell proliferation and migration, in which PARP1 acts as a negative transcription factor augmenting TFPI2 promoter DNA methylation. In conclusion, these results suggested that PARP1 accelerates the process of hyperglycemia-induced neointimal hyperplasia via promoting VSMCs proliferation and migration in a TFPI2 dependent manner.

Six-month results of stenting of the femoropopliteal artery and predictive value of interleukin-6: Comparison with high-sensitivity C-reactive protein

OBJECTIVES

To determine the association of pre- and postinterventional serum levels of interleukin-6 and high-sensitivity C-reactive protein at the six-month evaluation of restenosis after stenting of the femoropopliteal artery.

METHODS

Sixty-eight consecutive patients with steno-occlusive femoropopliteal artery disease of Rutherford category III or IV who underwent stent implantation were included. Six-month patency was evaluated with color-coded duplex ultrasound. The association of in-stent restenosis with interleukin-6 and high-sensitivity C-reactive protein levels at baseline, and 24-h postintervention was assessed with a multivariate logistic regression analysis.

RESULTS

In-stent restenosis was found in 15 patients (22.1%) within six months. Interleukin-6 and high-sensitivity C-reactive protein levels were significantly increased at 24-h postintervention compared to their preintervention values (p < 0.001 and p = 0.002, respectively). Interleukin-6 values at baseline (odds ratio, 1.11; 95% confidence interval: 1.00, 1.23; p = 0.044) and 24-h postintervention (odds ratio, 1.04; 95% confidence interval: 1.02, 1.06; p < 0.001) were independently associated with six-month in-stent restenosis. Twenty-four-hour postinterventional high-sensitivity C-reactive protein levels were also found to be related to restenosis (odds ratio, 1.15; 95% confidence interval: 1.04, 1.26; p = 0.006), but high-sensitivity C-reactive protein levels at baseline did not show an independent association with in-stent restenosis (odds ratio, 0.57; 95% confidence interval: 0.35, 1.80; p = 0.667). Smoking, diabetes mellitus, and cumulative stent length were other parameters associated with an increased risk for in-stent restenosis.

CONCLUSIONS

Femoropopliteal artery angioplasty with stent placement induces an inflammatory response. Interleukin-6 is a powerful independent predictor of intermediate-term outcomes for stenting of the femoropopliteal artery, suggesting that its predictive value may be superior to that of high-sensitivity C-reactive protein.

Is There a Safety Concern for Drug-Coated Balloons in Peripheral Arterial Disease?

PURPOSE OF REVIEW

Drug-coated balloons (DEB) and drug-eluting stents (DES) emerged as a tool to aid in lowering the rates of neointimal hyperplasia and target lesion restenosis following endovascular peripheral arterial disease (PAD) interventions.

RECENT FINDINGS

Although the initial trials comparing these devices with non-drug balloons and stents showed favorable results, more recent data raised concerns regarding the mid to long-term safety of these devices. In this review, we will discuss the evolution of endovascular therapy for PAD, with highlights regarding the recent debates on the long-term safety of the drug-coated devices for treatment of PAD.

Early Carotid Occlusion After Endarterectomy in a Patient With a Mutation for MTHFR A1298C Polymorphism

INTRODUCTION

Significant carotid stenosis is a well-documented risk factor for ischemic stroke. Carotid endarterectomy (CEA) and carotid artery stenting are effective procedures for the prevention of stroke in patients with this disease. However, the occurrence of restenosis could contribute to an increase in the risk of ischemic stroke.

CASE REPORT

A 79-year-old woman was admitted to the Neurosurgical Department to undergo a CEA because of a progressive stenosis. At the 3-month radiologic follow-up, the examinations showed a carotid restenosis. She was immediately started on a double-antiplatelet therapy. Blood samples revealed high levels of homocysteine and genetic tests showed a homozygous mutation for methylene tetrahydrofolate reductase A1298C polymorphism. Folic acid associated with pyridoxine was added to the treatment. Radiologic follow-ups showed no changes in the stenosis degree.

CONCLUSIONS

Even if the association between homocysteine and carotid restenosis after CEA is unclear, an initial screening before the surgical procedure could be useful to promptly treat this condition and probably reduce the risk of this complication. In the case of homozygous mutation, the selection of patients and the appropriate therapy could reduce the risk of carotid restenosis.

Effect of metabolic syndrome on the response to arterial injury

BACKGROUND

Metabolic syndrome is now an epidemic in the United States population. Intimal hyperplasia remains the principal lesion in the development of restenosis after vessel wall injury. The aim of this study is to characterize the changes induced in wall morphology in the developing intimal hyperplasia within a murine model in the presence of diabetes (type 1) and metabolic syndrome.

METHODS

Control (wild type B6), Non Obese Diabetic, and metabolic syndrome (RCS-10) mice were used. The murine femoral wire injury model was used in which a micro wire is passed through a branch of the femoral and used to denude the common femoral and iliac arteries. Specimens were perfusion fixed and sections were stained with hematoxylin and eosin and Movat stains such that dimensional and compositional morphometry could be performed using an ImagePro system. Additional stains for proliferation and apoptosis were used.

RESULTS

In control mice, the injured femoral arteries develop intimal hyperplasia, which is maximal at 28 d and remains stable to day 56. Sham-operated vessels do not produce such a response. In diabetic mice, the intimal response increased 5-fold with a 2-fold increase in proteoglycan deposition, whereas in the metabolic syndrome mice there was a 6-fold increase in the intimal response and a similar increase in proteoglycan deposition. Collagen deposition was different with a 22-fold increase over control in collagen deposition in diabetes and a 100-fold increase over control in collagen deposition in metabolic syndrome as compared with the control injury mice. Maximal vascular smooth muscle cell (VSMC) proliferation was decreased in both diabetes and metabolic syndrome compared with controls, whereas early cell apoptosis in both diabetes and metabolic syndrome was sustained over a longer period of time compared with wild-type mice.

CONCLUSIONS

These data demonstrate that development of intimal hyperplasia is markedly different in diabetes and metabolic syndrome compared with controls, with an increase in collagen deposition, a reduction in VSMC proliferation, and an increase in early VSMC apoptosis. These findings suggest that preventative strategies against restenosis must be tailored for the diabetic and metabolic syndrome patients.