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PubMed1995

Detection of Chlamydia pneumoniae TWAR in human coronary atherectomy tissues.

Chlamydia pneumoniae TWAR has been associated with coronary heart disease by seroepidemiologic studies and direct detection of the organism in atheromatous lesions of coronary arteries and aorta. In this study, 38 fresh tissue specimens from patients with coronary artery lesions that were treated by directional coronary atherectomy were tested for C. pneumoniae. Twenty-three specimens were from patients with primary lesions and 15 were from patients with restenoses. C. pneumoniae was detected by polymerase chain reaction (PCR), immunocytochemical stain (ICC), or both in 20 of 38 specimens. Using cell identity markers, the organism was localized to macrophages. Ultrastructural evidence of the organism was found in the 2 specimens examined by transmission electron microscopy, which were also positive by both ICC and PCR. C. pneumoniae was found more frequently in tissues from restenoses than in primary lesions (P = .17). There was no relation between the frequency of detection of the organism and C. pneumoniae-specific antibody titers.

Adult↗
PubMed1996

Failure to detect Chlamydia pneumoniae in coronary atheromas of patients undergoing atherectomy.

To further investigate a proposed relationship between Chlamydia pneumoniae and coronary heart disease, coronary atheromas were collected from patients undergoing percutaneous atherectomy. Fifty-eight atheroma specimens were examined by culture and polymerase chain reaction (PCR) and 22 by electron microscopy. All were negative for C. pneumoniae, except a single specimen that was PCR-positive. These results differ from studies in other populations, in which this organism was identified by nonculture methods within coronary atheromas obtained at autopsy. Anti-C. pneumoniae antibody titers from 65 of the patients were compared with those of 28 asymptomatic controls. IgG titers were higher in controls than in patients. There is no evidence that C. pneumoniae exists within atheromas in this study population, nor does seroprevalence correlate with the presence of coronary disease in these patients.

Adult↗
PubMed1993

Angioplasty, stenting, atherectomy, and laser treatment after coronary artery bypass grafting.

Saphenous vein grafts remain an essential part of coronary artery bypass surgery. However, their inferior long-term patency due to graft attrition often means recurrent ischemia or infarction. Repeat surgical revascularization carries a significantly higher morbidity and mortality and is frequently associated with less symptomatic improvement as compared with the initial surgery. Thus, nonsurgical alternatives are preferred in such a situation, particularly when the lesions are technically approachable and amenable to these transcatheter procedures. Traditionally, percutaneous transluminal coronary angioplasty has been the standard approach. However, there are certain shortcomings of this technique, principally its inadequacy in treating certain adverse lesion morphologies. Problems include an appreciable risk of coronary debris embolization and acute complications in old vein grafts, and the prohibitively high restenosis rate for stenoses situated at the ostium or the proximal and middle segments of grafts. Newer, second-generation intravascular techniques such as stents, atherectomy, and laser procedures have been introduced in an effort to overcome these problems. This review presents an update of the results of these new tools together with some suggestions on their clinical utility in a vein graft setting.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

Discharge teaching for the directional coronary atherectomy patient.

Due to the short length of stay for directional coronary atherectomy (DCA) patients, critical care nurses play a vital role in providing patients with discharge teaching. Decreased length of stay has left very little time for teaching DCA patients. It is critical for nurses to focus on key points and use concepts and words the patient immediately understands. This article describes key teaching strategies and provides sample written discharge teaching sheets for use in discharge teaching of the DCA patient.

Aged↗
PubMed1996

Clinical and postmortem outcome of "no-reflow' phenomenon in a patient treated with rotational atherectomy.

In the 77-year-old woman described, atherectomy of a circumflex artery with the Rotablator device was complicated by "no reflow." Ten days later, a 75% right coronary artery stenosis was successfully managed by balloon angioplasty. On the following day, acute closure of this vessel resulted in death. Gross examination of the heart showed features of recent posterior infarction, and microscopic study revealed atheroemboli in myocardial arterioles. We conclude that high-speed pulverization of atherosclerotic plaque can cause clinically significant emboli.

Aged↗
PubMed2001

Increased plasminogen activator inhibitor-1 and apolipoprotein (a) in coronary atherectomy specimens in acute coronary syndromes.

BACKGROUND: Although increased tissue factor expression is known in vulnerable plaques, there is no reported study to compare plaque fibrinolysis in stable and unstable plaques. This study investigates the extent of plasminogen activator inhibitor-1 (PAI-1) and apolipoprotein (a) [apo(a)] in the plaques of different types of coronary artery disease as well as the correlation between these molecules and infiltration of macrophages to plaques. METHODS: Using immunohistochemical staining, we examined PAI-1 expression and apo(a) deposition in coronary atherosclerotic specimens obtained by directional coronary atherectomy from 19 patients with acute myocardial infarction (AMI), 12 with unstable angina pectoris (UAP), and 13 with stable angina pectoris (SAP). The percentages of the total areas of specimens stained with PAI-1 or apo(a) were estimated by an NIH image program. The proportion of macrophages as a percentage of all cells in plaques was calculated as the macrophage density. RESULTS: We found significantly higher percentages of total areas of specimens stained with PAI-1 in AMI (25.5 +/- 8.6%, P < 0.001) and UAP (22.2 +/- 10.4%, P < 0.005) than in SAP (9.5 +/- 5.0%), as well as with apo(a) (AMI; 11.7 +/- 7.1%, P < 0.005, UAP; 11.1 +/- 5.5%, P < 0.01 versus SAP; 3.9 +/- 1.5%). Linear regression analysis of all the samples showed a correlation between PAI-1 or apo(a) and macrophage density (PAI-1: r = 0.75, P < 0.001 and apo(a): r = 0.56, P < 0.001). CONCLUSIONS: Our results suggest a possible contribution of increased PAI-1 and apo(a) in plaques to the pathogenesis of acute coronary syndromes including impaired fibrinolysis.

Aged↗
PubMed2006

Composition of coronary plaques obtained by directional atherectomy in stable angina: its relation to serum lipids and statin treatment.

OBJECTIVES: The stability and inflammatory activity in atherosclerotic plaques may be modulated by lipids and lipoproteins as well as the pleiotropic effects of statins. The aim of this study was to analyse the effect of statin treatment as well as the relation of plasma lipids and lipoproteins to tissue composition in atherosclerotic plaques. DESIGN: Patients with stable angina and coronary plaques suitable for directional coronary atherectomy (DCA) were randomized to atorvastatin (80 mg once daily) or placebo (29 randomized, 22 underwent DCA, 11/group). After an average treatment of 10 weeks, patients underwent DCA, tissue specimens were obtained, and the tissue composition was determined by immunohistochemistry. RESULTS: Atorvastatin reduced the T-cell content, but did not change lipid, collagen, smooth muscle cell, or macrophage content. Plasma levels of apolipoprotein AI (apoAI) correlated positively with tissue collagen and inversely with metalloproteinase-9 and macrophage content. About half the specimens contained neutrophil granulocytes. CONCLUSIONS: Short-term atorvastatin treatment tended to reduce the T-cell content of atherosclerotic plaques, indicating modulation of cell-mediated immunity. High plasma levels of apoAI correlated with increased collagen content and reduced inflammation, supporting the notion that plasma apoAI stabilizes atherosclerotic plaques. The significance of neutrophils in the lesions merits further study.

Adult↗
PubMed1992

Rotational angioplasty and directional atherectomy to treat complex lesions of the right coronary artery.

A combination of interventional devices including the Rotablator and directional coronary atherectomy (DCA) was used to treat a 39-year-old patient with a complex lesion of the right coronary artery. The devices enabled the recanalization and reconstruction of the diseased vessel without laceration or dissection, leaving a smooth-edged segment. The histological analysis of the tissue obtained from DCA revealed no predictors of restenosis, like highly cellular material or media. Thus, combination of mechanical interventional devices allowed to treat a highly complex lesion without lacerating the vessel and leaving an excellent acute and long-term outcome.

Adult↗
PubMed1997

Papillary endothelial hyperplasia in a TEC coronary atherectomy specimen.

Angiography in a 37 year old female with a three week history of typical crescendo angina found an 80% stenosis of the proximal left anterior descending (LAD) artery. The patient underwent percutaneous transluminal coronary angioplasty involving TEC artherectomy of the LAD artery. The specimen removed by atherectomy was found to have the appearance of papillary endothelial hyperplasia. This is an unusual histological diagnosis that occurs in association with thrombus. It is rarely found within arterial vessels and has not been reported in a coronary artery. Papillary endothelial hyperplasia is now thought to be a form of organising thrombus, probably dependent on the production of basic fibroblast growth factor by the endothelium.

Adult↗
PubMed1998

Tyrosine phosphorylation of platelet derived growth factor beta receptors in coronary artery lesions: implications for vascular remodelling after directional coronary atherectomy and unstable angina pectoris.

BACKGROUND: Growth factors such as platelet derived growth factor (PDGF) have been postulated to be important mediators of neointimal proliferation observed in atherosclerotic plaques and restenotic lesions following coronary interventions. Binding of PDGF to its receptor results in intrinsic receptor tyrosine kinase activation and subsequent cellular migration, proliferation, and vascular contraction. AIMS: To investigate whether the concentration of PDGF beta receptor tyrosine phosphorylation obtained from directional coronary atherectomy (DCA) samples correlate with atherosclerotic plaque burden, the ability of diseased vessels to remodel, coronary risk factors, and clinical events. METHODS: DCA samples from 59 patients and 15 non-atherosclerotic left internal thoracic arteries (LITA) were analysed for PDGF beta receptor tyrosine phosphorylation content by receptor immunoprecipitation and antiphosphotyrosine western blot. The amount of PDGF beta receptor phosphorylation was analysed in relation to angiographic follow up data and clinical variables. RESULTS: PDGF beta receptor tyrosine phosphorylation in the 59 DCA samples was greater than in the 15 non-atherosclerotic LITA (mean (SD) 0.84 (0.67) v 0.17 (0.08) over a control standard, p < 0.0001). As evaluated by stepwise regression analysis, incorporation of both PDGF beta receptor tyrosine phosphorylation and immediate gain correlated strongly (adjusted r2 = 0.579) with late loss, although PDGF beta receptor tyramine phosphorylation alone correlated poorly with late loss. Multivariate regression analysis of coronary risk factors and clinical events revealed unstable angina as the most significant correlate of PDGF beta receptor tyrosine phosphorylation (F value 20.009, p < 0.0001). CONCLUSIONS: PDGF beta receptor tyrosine phosphorylation in atherosclerotic lesions is increased compared with non-atherosclerotic arterial tissues. The association of PDGF beta receptor tyrosine phosphorylation with immediate gain strongly correlates with vascular remodelling. PDGF beta receptor tyrosine phosphorylation correlates with unstable angina pectoris.

Angina, Unstable↗
PubMed1993

Histopathological examination of specimens removed during directional coronary atherectomy in patients presenting with crescendo angina show mural thrombus.

Thrombus formation over a fissured coronary atheromatous plaque has been shown by post mortem histological examination to be the pathophysiological mechanism responsible for myocardial ischaemia in those patients who died following a crescendo pattern of angina. Histological examination of plaques responsible for a crescendo pattern of angina in patients who do not die has not been available until recently. We describe two patients who presented with a crescendo pattern of angina. A new technique of coronary revascularization, directional coronary atherectomy, produced symptomatic relief and resolution of myocardial ischaemia. Histological examination of material from the stenosis responsible for their myocardial ischaemia, obtained using this technique, confirmed thrombus formation overlying a fissured atheromatous plaque.

Adult↗
PubMed2000

Markedly eccentric peripheral vascular stenoses: percutaneous atherectomy with an endomyocardial biopsy device.

In 23 patients, percutaneous atherectomy was performed with an endomyocardial biopsy device in 27 eccentric stenoses of lower limb arteries. The mean percentage stenosis was reduced from 82% to 14% (P: <.001). Histopathologic examination revealed no media or adventitial tissue in the extracted particles. The technical success and complication rates were similar to those reported for conventional percutaneous transluminal angioplasty of short symmetric lesions.

Aged↗
PubMed1998

Directional coronary atherectomy in acute myocardial infarction.

Balloon angioplasty (percutaneous transluminal coronary angioplasty, PTCA) is an established common strategy in the treatment of acute myocardial infarction (MI) with high success rates but a 5-10% incidence of reclosure/reinfarction due to thrombus and/or intimal flaps. Directional coronary atherectomy (DCA) by removing plaque/thrombus and achieving larger postprocedural luminal diameter may further decrease the incidence of reclosure/reinfarction, with a resultant better in-hospital outcome in this setting. We analyzed the clinical, procedural and in-hospital outcome of patients who underwent DCA or PTCA within 48 h of MI. Long lesions (>20 mm), large angiographic intracoronary thrombus, lesions in a bend, heavy calcification, and vessel diameter <3.0 mm were excluded from the study. Although slow flow occurred more frequently during DCA (17 vs. 9% during PTCA, p = 0.04), procedural success (<50% final diameter stenosis with TIMI-3 flow) was achieved in 96% of DCA and 92% of PTCA group (nonsignificant). Acute closure occurred in 9% of the PTCA group versus 2% of the DCA (p = 0.05), and the composite endpoint of in-hospital reinfarction, reintervention, bypass surgery or death was present in 9% of PTCA cases versus none of DCA cases (p = 0.03). There were no major peripheral vascular complications requiring surgery in either group. Therefore, DCA appears safe and effective in selected patients with recent MI, and is associated with a low incidence of major clinical complications.

Aged↗
PubMed2001

High-speed rotational atherectomy in the treatment of bifurcation-type coronary lesions.

BACKGROUND: Bifurcational coronary lesions present a major interventional challenge. The differential cutting mechanism of high-speed rotational atherectomy (HSRA) may provide a favourable technique of treating this complex lesion subtype. METHODS: We evaluated the use of HSRA (32 lesions) compared to balloon angioplasty (BA) (118 lesions), with provisional stenting in both groups, in a non-randomised, retrospective study of 150 bifurcation-type lesions. RESULTS: The HSRA/stent group had a high primary success rate of 97%, an acceptably low in-hospital event rate of 9% and an overall major adverse cardiac event (MACE) rate at a mean follow-up period of 15 +/- 3.4 months of 22.5% with a target lesion revascularisation (TLR) rate of 18.7%. Procedural success in the BA/stent group was 81% with an in-hospital event rate of 14.4%, and the overall MACE rate at follow-up was 27.5% with a TLR rate of 23%. We achieved a greater acute gain in minimal luminal diameter and a lesser percentage of residual stenosis after intervention in the HSRA/stent group compared to the BA/stent group (p < 0.01). Outcome at follow-up favoured the HSRA/stent group, although the difference did not reach statistical significance. CONCLUSION: HSRA with provisional stenting provided a safe and effective means of treating bifurcation lesions.

Angioplasty, Balloon, Coronary↗
PubMed2003

Smooth muscle cell outgrowth from coronary atherectomy specimens in vitro is associated with less time to restenosis and expression of a key Transcription factor KLF5/BTEB2.

Atherectomy specimens offer an opportunity to study the biology of coronary artery lesions. We cultured smooth muscle cells (SMCs) from specimens obtained from 24 patients with coronary restenosis after angioplasty to study the relationship between activity of SMCs (in vitro outgrowth) and the time course of restenosis. We also examined expression of a Kruppel-like zinc-finger transcription factor 5 (KLF; also known as BTEB2 and IKLF), which is markedly induced in activated SMCs, in the same specimens. SMC outgrowth was observed in 9 of 24 specimens (37.5%). Restenosis occurred sooner (p < 0.01) in patients whose specimens showed outgrowth compared to those whose specimens showed no outgrowth. Immunostaining for KLF5 was more common in specimens with outgrowth (89 vs. 20%, p < 0.01). These data suggest that the number of activated SMCs in lesions may determine in vitro outgrowth and also affect the time to restenosis.

Aged↗
PubMed1996

The treatment of chronic hemodialysis vascular access by directional atherectomy.

Directional atherectomy (DA) was developed as a new therapeutic modality for coronary artery disease. For the past 3 years, we have applied DA intervention to vascular access failure with either poor blood flow rate or high venous pressure. DA intervention was performed on 27 lesions of 16 hemodialyzed patients. A reduction of stenosis to less than 20% of that before treatment was judged a technical success, and the rate of technical success was 84%. All patients showed adequate blood flow rates after DA intervention, indicating initial success. Although restenotic events occurred frequently, repeated DA interventions could be performed successfully. The patency rate at 1 month after DA intervention was 100%, at 3 months 93%, at 6 months 92% and at 12 months 75%. The short-term patency rate of DA was more satisfactory than the results of percutaneous transluminal angioplasty as reported by several investigators. Regarding the site of stenosis, restenotic events were relatively fewer in the lesions occurring at the native vein compared to those at graft-venous anastomotic sites. Eccentric-type stenosis was also associated with fewer restenotic events than circumferential-type stenosis. These results suggest that eccentric-type stenosis at the native vein is the most suitable lesion for the application of DA intervention in terms of long-term patency. As no severe complications occurred after DA intervention, this would appear to be a useful therapeutic modality for the correction of vascular access failure.

Aged↗
PubMed2002

Superoxide generation in directional coronary atherectomy specimens of patients with angina pectoris: important role of NAD(P)H oxidase.

OBJECTIVE: NADH/NADPH oxidase is an important source of reactive oxygen species (ROS) in the vasculature. Recently, we demonstrated that p22(phox), an essential component of this oxidase, was expressed in human coronary arteries and that its expression was enhanced with the progression of atherosclerosis. The present study was undertaken to investigate its functional importance in the pathogenesis of coronary artery disease. For this aim, the expression of p22(phox), the distribution of oxidized low density lipoprotein (LDL), and the generation of ROS in directional coronary atherectomy (DCA) specimens were examined. METHODS AND RESULTS: DCA specimens were obtained from patients with stable or unstable angina pectoris. The distribution of p22(phox) and of oxidized LDL was examined by immunohistochemistry. The generation of superoxide in DCA specimens was assessed by the dihydroethidium method and lucigenin-enhanced chemiluminescence. ROS were closely associated with the distribution of p22(phox) and oxidized LDL. Not only inflammatory cells but also smooth muscle cells and fibroblasts generated ROS. There was a correlation between ROS and the expression of p22(phox) or oxidized LDL. The generation of ROS was significantly higher in unstable angina pectoris compared with stable angina pectoris. CONCLUSIONS: ROS generated by p22(phox)-based NADH/NADPH oxidase likely mediate the oxidative modification of LDL and might play a major role in pathogenesis of atherosclerotic coronary artery disease.

Angina Pectoris↗
PubMed2000

IL-8 is an angiogenic factor in human coronary atherectomy tissue.

BACKGROUND: Interleukin-8 (IL-8), a CXC chemokine that induces the migration and proliferation of endothelial cells and smooth muscle cells, is a potent angiogenic factor that may play a role in atherosclerosis. Previously, IL-8 has been reported in atherosclerotic lesions and circulating macrophages from patients with atherosclerosis. Therefore, we sought to determine whether IL-8 plays a role in mediating angiogenic activity in atherosclerosis. METHODS AND RESULTS: Homogenates from 16 patients undergoing directional coronary atherectomy (DCA) and control samples from the internal mammary artery (IMA) of 7 patients undergoing bypass graft surgery were assessed for IL-8 content by specific ELISA, immunohistochemistry, and in situ hybridization for IL-8 mRNA. The contribution of IL-8 to net angiogenic activity was assessed using the rat cornea micropocket assay and cultured cells. IL-8 expression was significantly elevated in DCA samples compared with IMA samples (1.71+/-0.6 versus 0.05+/-0.03 ng/mg of total protein; P<0.01). Positive immunolocalization of IL-8 was found exclusively in DCA tissue sections, and it correlated with the presence of factor VIII-related antigen. In situ reverse transcriptase polymerase chain reaction revealed the expression of IL-8 mRNA in DCA tissue. Corneal neovascular response, defined by ingrowth of capillary sprouts toward the implant, was markedly positive with DCA pellets, but no constitutive vessel ingrowth was seen with IMA specimens. Neutralizing IL-8 attenuated both the in vivo corneal neovascular response and the in vitro proliferation of cultured cells. CONCLUSIONS: The results suggest that, in human coronary atherosclerosis, IL-8 is an important mediator of angiogenesis and may contribute to plaque formation via its angiogenic properties.

Angina Pectoris↗