Arterial Wall Plaque Research Articles

Nanomechanical properties of calcification, fibrous tissue, and hematoma from atherosclerotic plaques

Clinical events such as heart attack and stroke can be caused by the rupture of atherosclerotic plaques in artery walls. Computational modeling is often used to better understand atherosclerotic disease progression to identify "vulnerable" plaques (i.e., those likely to rupture) and to tailor treatments according to tissue composition. However, because of the heterogeneity of plaque tissue, there are limited data available on the material properties of individual plaque constituents. The goal of this study was to use nanoindentation to measure the mechanical properties of blood clots, fibrous tissue, partially calcified fibrous tissue, and bulk calcifications from human atherosclerotic plaque tissue. Fourier transform infrared (FTIR) spectroscopy was used to quantify the amount of mineral and lipid in each tissue region tested. The results demonstrate that the stiffness of plaque tissue increases with increasing mineral content. In addition, by providing the first experimental data on atherosclerotic calcifications, these data show that some of the estimated modulus values commonly used in computational models greatly underestimate the stiffness of the fully calcified tissue.

Efficacy and Safety of the Angioseal Vascular Closure Device Post Antegrade Puncture

In this study, the efficacy and safety of the Angioseal vascular closure device post antegrade puncture of the common femoral artery (CFA) for lower limb vascular interventional procedures are evaluated. A retrospective analysis of the medical records of 60 consecutive patients who were referred for interventional procedures in the superficial femoral artery (SFA) or popliteal artery (popl. art.) was performed. Antegrade puncture was successfully performed in 58 of 60 patients (96.6%). Indications included right SFA angioplasty (n = 35), left SFA angioplasty (n = 17), right popl. art. angioplasty (n = 5), and left popl. art. angioplasty (n = 1). Hemostasis was achieved by, on an intention-to-treat basis, the Angioseal vascular closure device in 46 patients and manual compression in 12 patients. Manual compression was used instead of Angioseal because of severe calcified arterial wall plaques (n = 7), failed deployment of the Angioseal (n = 4), and left SFA dissection (n = 1). There were no major recorded complications in the Angioseal group despite the use of antiplatelet or anticoagulant medications. Twenty-three (50%) of the patients in the Angioseal group were discharged within 24 h. Thirty-seven of the 46 patients who received an Angioseal device had undergone a previous ipsilateral CFA puncture (time range, 2 days to 56 months; mean, 6.2 months). Nine of these patients had undergone ipsilateral Angioseal deployment in the previous 3 months. We conclude that the Angioseal vascular closure device is a safe and efficient means of achieving hemostasis post antegrade puncture.

How to Make Sure the Beat Goes On

Heart disease remains the leading killer of women in the United States, although fewer than half of US women know it. Despite progress, American women are 6 times more likely to die of heart disease than of breast cancer, and heart disease kills more women over age 65 than all cancers combined. The most common form of heart disease, coronary heart disease, results from atherosclerosis, or the accumulation of fatty plaques in artery walls that causes arteries to narrow. If a blood clot or plaque rupture blocks a narrowed artery leading to the heart, it can cause a heart attack. Several factors are known to increase the risk for heart disease. The more risk factors a woman has, the greater her risk of a heart attack. Some risk factors cannot be controlled, such as increasing age and a family history of heart disease. Women with a father or brother who developed heart disease before age 55 or a mother or sister who developed heart disease before age 65 are at increased risk. Race is also a factor, with black women being more likely than white women to develop heart disease. However, the majority of factors that contribute to heart disease, including smoking, high cholesterol, high blood pressure, and high blood sugar, can be controlled or modified by making simple changes in your lifestyle and, if necessary, taking certain medicines. Using a tool developed by investigators from the Framingham Heart Study, the longest-running study of heart disease, you can estimate whether your chance of having a heart attack or dying of heart disease during the next 10 years is “high,” “intermediate,” or “low” (see Table 1 or go to http://hin.nhlbi.nih.gov/atpiii/calculator.asp or http://www. nhlbi.nih.gov/about/framingham/ riskabs.htm). You receive points on the basis of your age, total cholesterol level, high-density lipoprotein (“good”) cholesterol level, …

Retinal arterial wall plaques in Susac syndrome

Purpose To demonstrate retinal arterial wall plaques (RAWPs) in patients with Susac syndrome, a disorder that consists of the triad of branch retinal artery occlusion, encephalopathy, and hearing loss. The clinician may misinterpret these RAWPs as emboli. Design Observational case series. Methods Four patients (one man and three women, aged 21–38 years) were examined and followed. Results Four patients with Susac syndrome had RAWPs in association with branch retinal artery occlusions. They were present in six of eight eyes. The plaques were yellow to yellow-white and located usually away from retinal bifurcations. Retinal arterial wall plaques occur at the midarteriolar segments, whereas Hollenhorst plaques occur at vascular bifurcations. Four of six eyes had resolution of the plaques. Conclusions Retinal arterial wall plaques may occur with branch retinal artery occlusions in Susac syndrome. This finding should help the clinician who is struggling to make a diagnosis in a patient with an enigmatic encephalopathy and/or hearing loss. These plaques may resolve over time.

Macrophage Scavenger Receptors and Atherosclerosis

A hallmark of atherosclerosis is the deposition of plasma cholesterol in atherosclerotic plaques in arterial walls. Key cellular components of atherosclerotic plaques are foam cells, which are derived from monocytes-macrophages. In order to elucidate the molecular mechanism of foam cell formation, we cloned and characterized cDNA for type I and II MSR. Type I and II MSR can bind an extraordinary wide range of ligands using its “charged collagen structure”, including modified low density lipoproteins (mLDL) and bacterial pathogens. MSR also mediates phagocytosis of apoptotic cells and cation-independent macrophage adhesion in vitro. Targeted disruption of type I and II MSR gene in mice results in a marked reduction in the size of atherosclerotic lesions in an animal deficient in apolipoprotein E. Macrophages from type I and II MSR deficient mice show a marked decrease in mLDL degradation activity in vitro, whereas mLDL clearance from the plasma occurs at a normal rate. In addition, type I and II MSR-knockout mice show an increased susceptibility to infection with Listeria monocytogenes or herpes simplex virus type I, indicating that type I and II MSR may play a part in host defense against pathogens.

Retinal Artery Obstruction and Atheromas Associated With Non-Hodgkin's Large Cell Lymphoma (Reticulum Cell Sarcoma)

A 71-year-old woman developed branch retinal artery obstruction as the presenting manifestation of a large cell non-Hodgkin's lymphoma. Multifocal chorioretinal scars were present in the same eye. She experienced progressive visual loss accompanied by development of multiple yellow retinal arterial wall plaques, extension of retinal opacification into other quadrants, and increasing vitreous cellular infiltration. Clinical diagnoses included branch retinal arterial obstruction caused by toxoplasmosis retinitis, multifocal choroiditis and panuveitis simulating the presumed ocular histoplasmosis syndrome, vitiliginous chorioretinitis, and the acute retinal necrosis syndrome. Four months after onset, the right eye was blind and was enucleated. Histopathologic examination revealed extensive lymphomatous infiltration and necrosis of the retina and optic nerve. The retinal arteries were partly obstructed by lymphomatous infiltration and atheromas. Subsequently, the left eye and central nervous system were involved by lymphoma.