Differential response of delayed healing and persistent inflammation at sites of overlapping sirolimus- or paclitaxel-eluting stents.

Background: Although effective coverage of challenging coronary lesions has warranted the use of overlapping drug-eluting stents, the histopathological response to stent overlap is unknown.

Methods And Results: The arterial reaction to overlapping Cypher or Taxus drug-eluting stents was examined in rabbits with bare metal stents, BxVelocity or Express, serving as controls. Single iliac artery balloon injury was followed by placement of 2 overlapping 3.

Extracellular matrix changes in stented human coronary arteries.

Background: Restenosis after stenting occurs secondary to the accumulation of smooth muscle cells (SMCs) and extracellular matrix (ECM), with the ECM accounting for >50% of the neointimal volume. The composition of the in-stent ECM has not been well characterized in humans.

Methods And Results: Postmortem human coronary arteries (n=45) containing stents underwent histological assessment of neointimal proteoglycans, hyaluronan, collagen (types I and III), SMCs, and CD44 (a cell surface receptor for hyaluronan).

Morphologic findings of coronary atherosclerotic plaques in diabetics: a postmortem study.

Objective: Coronary atherosclerotic plaque composition of diabetic subjects and localization of receptor for advanced glycation end products (RAGE) and its ligands have not been extensively studied.

Methods And Results: Hearts from diabetic subjects and age, race, and sex-matched nondiabetic subjects dying suddenly were examined. Coronary arteries were dissected and lesions were evaluated for plaque burden, necrotic core size, and inflammatory infiltrate.

Uptake of 111In-Z2D3 on SPECT imaging in a swine model of coronary stent restenosis correlated with cell proliferation.

Unlabelled: Small targets such as cell proliferation in the coronary arteries may potentially be detected with single-photon imaging using high-radiotracer-specific activity. We hypothesized that an antibody linked to polymers to increase specific radioactivity can be visualized on SPECT images and that counts in the target will correlate with the strength of the biologic signal.

Methods: Twenty-four stents were placed using the balloon overexpansion technique in the coronary arteries of 14 juvenile domestic swine.

Targeting of apoptotic macrophages and experimental atheroma with radiolabeled annexin V: a technique with potential for noninvasive imaging of vulnerable plaque.

Background: Apoptosis is common in advanced human atheroma and contributes to plaque instability. Because annexin V has a high affinity for exposed phosphatidylserine on apoptotic cells, radiolabeled annexin V may be used for noninvasive detection of apoptosis in atherosclerotic lesions.

Methods And Results: Atherosclerotic plaques were produced in 5 rabbits by deendothelialization of the infradiaphragmatic aorta followed by 12 weeks of cholesterol diet; 5 controls were studied without manipulation.

Intraplaque hemorrhage and progression of coronary atheroma.

Background: Intraplaque hemorrhage is common in advanced coronary atherosclerotic lesions. The relation between hemorrhage and the vulnerability of plaque to disruption may involve the accumulation of free cholesterol from erythrocyte membranes.

Methods: We stained multiple coronary lesions from 24 randomly selected patients who had died suddenly of coronary causes with an antibody against glycophorin A (a protein specific to erythrocytes that facilitates anion exchange) and Mallory's stain for iron (hemosiderin), markers of previous intraplaque hemorrhage.

Differential accumulation of proteoglycans and hyaluronan in culprit lesions: insights into plaque erosion.

Objective: The importance of the extracellular matrix molecules versican, biglycan, decorin, and hyaluronan in plaque instability has not been recognized.

Methods And Results: Coronary lesions with acute thrombi and stable plaques were examined for the accumulation and distribution of specific proteoglycans and hyaluronan at culprit sites. The cell surface receptor for hyaluronan, CD44, and smooth muscle (SM) cell maturation markers were also assessed.

A novel rat model of carotid artery stenting for the understanding of restenosis in metabolic diseases.

The effects of risk modifiers such as diabetes, obesity and hypertension on vascular healing after stent deployment are largely unknown, because of a lack of an appropriate animal model to study. Since many inbred strains of rats expressing these phenotypes are available, we validated a carotid artery model of in-stent restenosis in the rat. A detailed histomorphometric analysis was performed on 2-cell Multi-Link(TM) stents (1.

Morphological predictors of restenosis after coronary stenting in humans.

Background: Experimental studies suggest that arterial injury and inflammation lead to increased neointimal growth after stenting. Despite the increased use of coronary stents in humans, there are only limited pathological data on the morphological features of in-stent restenosis.

Methods And Results: Detailed histology was performed on 116 stents, implanted > or =90 days in 87 coronary arteries, from 56 patients (mean age, 59+/-13 years).