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Background: The association of shear stress (SS) with in-stent restenosis after bare metal stenting is not clear. We investigated the significance of SS on predicting areas with neointima thickness (NT) in humans and the effect of vascular brachytherapy (VBT) following coronary artery stenting on the relationship of SS with NT. Methods: By using coronary angiography and intravascular ultrasound, we performed three-dimensional (3D) artery and stent reconstruction in 14 patients at 8-month follow-up after bare metal stenting with (stent&VBT group; 7 patients) or without (stent group; 7 patients) adjunctive beta-VBT. In-stent SS was calculated by applying computational fluid dynamics to the stent reconstruction and NT was determined in 3D space. Results: NT was significantly increased in the stent group (0.2 +/- 0.16 mm vs. 0.07 +/- 0.18 mm, p

Hellenic J Cardiol

In this study we investigated the accuracy of monoplane and biplane quantitative coronary angiography in estimating the luminal dimensions, Using intracoronary Ultrasound as gold standard. Biplane angiography and intracoronary ultrasound were performed in 24 arterial segments. The end-diastolic intracoronary ultrasound Frames Were manually selected and segmented. In 2 end-diastolic X ray projections, quantitative coronary angiography was performed and a novel methodology was applied to register the segmented frames onto the processed angiographic images. The luminal areas determined by quantitative coronary angiography in 1 (monoplane) and 2 projections (mean) were compared with those determined 1)), intracoronary ultrasound. The obtained correlation coefficients for the monoplane and mean estimations were 0.69 +/- 0.12 and 0.77 +/- 0.08, respectively. It would appear that by increasing the angle between the biplane projections, the correlation between intracoronary ultrasound and mean estimations improves. Our results provide evidence that orthogonal biplane angiography is more reliable and should be preferred to assess luminal dimensions. Angiology

A 58-year-old woman presented with gangrene of the left upper arm stump caused by an arteriovenous malformation originating from the subclavian artery. She had been treated unsuccessfully in the past with repeated attempts of coil embolization and debridement, but finally she underwent arm amputation. A 14 mm diameter occlusion self-expandable stent was placed in the left subclavian artery via ipsilateral brachial artery access, with immediate and complete interruption of arterial supply to the vascular malformation. This minimally invasive treatment provides an alternative method of management of arteriovenous malformations in the subclavian region. Vascular

The platelet integrin receptor alpha(IIb)beta(3) plays a critical role in thrombosis. We have shown previously that the octapeptide YMESRADR, corresponding to sequences 313 to 320 of the human alpha(IIb) subunit, inhibits human platelet activation and fibrinogen binding to alpha(IIb)beta(3), possibly interacting with the ligand. We investigated the effect of YMESRADR on electrically induced carotid artery thrombosis in New Zealand white rabbits. Peptide was administered via the femoral vein, starting 60 min before and continuing for 90 min after the electrical stimulation. Carotid blood flow was monitored for 90 min after the electrical stimulation. The peptide effects on platelet aggregation, in vitro and ex vivo, and on various coagulation, bleeding, and hemostatic parameters were evaluated. YMESRADR significantly inhibited rabbit platelet aggregation in vitro in a dose-dependent manner. It is important that peptide administration in vivo, at doses ranging from 3 to 15 mg/kg, prolonged the duration of the patency of the carotid artery, and no artery occlusion was observed until the end of the study (90 min after electrical stimulation). Furthermore, YMESRADR administration reduced platelet aggregation ex vivo and thrombus weight; however, these reductions reached statistical significance, compared with the control group, at the peptide doses of 12 and 15 mg/kg. YMESRADR did not affect any coagulation parameter studied and the hemostatic response observed in control animals. Thus, YMESRADR represents a novel antiplatelet agent that can inhibit thrombus formation effectively and carotid artery occlusion without causing hemorrhagic complications in a rabbit model of arterial thrombosis. Journal of Pharmacology and Experimental Therapeutics

BACKGROUND: It is not clear whether the correction of anemia with erythropoietin (rhuEpo) in patients with chronic kidney disease (CKD) has any benefit on cardiac function and geometry. Most studies are based on indices of systolic function and left ventricular mass (LVM) and the results are conflicting. PATIENTS AND METHODS: We sought to investigate the effect of rhuEpo on LV systolic and diastolic performance using conventional and novel echocardiographic indices. Thirty one patients with CKD (stage 3 or 4) were included. Fifteen patients (group I) treated with rhuEpo targeting at Hb >or=13.0 g/dL, while the remaining (group II) were not treated. Clinical and laboratory parameters were recorded at baseline and 1 year later. Ejection fraction (EF) and LVM were carefully determined. Diastolic function was assessed by mitral inflow indices (E and A wave velocities, Edt deceleration time and E/A) and novel indices of mitral annulus motion using Tissue Doppler Imaging (Em, Am, and E/Em). An index of global cardiac function (Tei) was also calculated. RESULTS: At baseline, the 2 groups had comparable clinical and laboratory characteristics. After 1 year, a significant improvement in Hb levels (13.6 +/- 1.2 vs 10.3 +/- 1.2 g/dL, p < 0.05) as well as in systolic and diastolic function indexes was observed in group I compared to group II patients: EF (70.5 +/- 7.6 vs 63.4 +/- 9.3%, p < 0.05), LVM (116.5 +/- 34.9 vs 155.6 +/- 51.6 g/m(2), p < 0.05), Edt (233.9 +/- 98.6 vs 166.9 +/- 45.1 ms, p < 0.05), Tei index (0.35 +/- 0.12 vs 0.51 +/- 0.17, p < 0.01) and E/Em (9.7 +/- 2.4 vs 14.8 +/- 5.2, p < 0.05), respectively. Blood pressure and heart rate did not show significant changes. CONCLUSIONS: Correction of anemia with rhuEpo in patients with CKD seems to improve cardiac performance and geometry. Cardiovasc Drugs Ther

Journal of Peptide Science

Europace

Objectives: The development of an automated, user-friendly system (ANGIOCARE), for rapid three-dimensional (3D) coronary reconstruction, integrating angiographic and, intracoronary ultrasound (ICUS) data. Methods: Biplane angiographic and ICUS sequence images are imported into the system where a prevalidated method is used for coronary reconstruction. This incorporates extraction of the catheter path from two end-diastolic X-ray images and detection of regions of interest (lumen, outer vessel wall) in the ICUS sequence by an automated border detection algorithm. The detected borders are placed perpendicular to the catheter path and established algorithms used to estimate their absolute orientation. The resulting 3D object is imported into an advanced visualization module with which the operator can interact, examine plaque distribution (depicted as a color coded map) and assess plaque burden by virtual endoscopy. Results: Data from 19 patients (27 vessels) undergoing biplane angiography and ICUS were examined. The reconstructed vessels were 21.3-80.2 mm long. The mean difference was 0.9 +/- 2.9% between the plaque volumes measured using linear 3D ICUS analysis and the volumes, estimated by taking into account the curvature of the vessel. The time required to reconstruct a luminal narrowing of 25 mm was approximately 10 min. Conclusion: The ANGIOCARE system provides rapid coronary reconstruction allowing the operator accurately to estimate the length of the lesion and determine plaque distribution and volume. (C) 2008 Wiley-Liss, Inc. Catheterization and Cardiovascular Interventions

A fuzzy rule-based decision support system (DSS) is presented for the diagnosis of coronary artery disease (CAD). The system is automatically generated from an initial annotated dataset, using a four stage methodology: 1) induction of a decision tree from the data; 2) extraction of a set of rules from the decision tree, in disjunctive normal form and formulation of a crisp model; 3) transformation of the crisp set of rules into a fuzzy model; and 4) optimization of the parameters of the fuzzy model. The dataset used for the DSS generation and evaluation consists of 199 subjects, each one characterized by 19 features, including demographic and history data, as well as laboratory examinations. Tenfold cross validation is employed, and the average sensitivity and specificity obtained is 62% and 54%, respectively, using the set of rules extracted from the decision tree (first and second stages), while the average sensitivity and specificity increase to 80% and 65%, respectively, when the fuzzification and optimization stages are used. The system offers several advantages since it is automatically generated, it provides CAD diagnosis based on easily and noninvasively acquired features, and is able to provide interpretation for the decisions made. IEEE Trans Inf Technol Biomed

Int J Cardiol

OBJECTIVES: The role of SLC19A1 -43T>C, MTHFR 677C>T and MS 2756A>G polymorphisms on red cell and plasma folate levels. DESIGN AND METHODS: Genotype analysis of the three polymorphisms. Red cell and plasma folate measurements in 64 patients with coronary artery disease. RESULTS: The non-wild type allele of SLC19A1 polymorphism -43T>C was associated with low red cell folate levels and the non-wild type allele of MTHFR polymorphism 677C>T with low plasma folate levels. CONCLUSION: SLC19A1 and MTHFR genes are differently associated with red cell and plasma folate levels. Clin Biochem

OBJECTIVE: Although nitroglycerin- and isoproterenol-augmented tilt tests are of equal value in the diagnosis of neurocardiogenic syncope in adults, no data exist in children. We compared the sensitivity and specificity of the 2 tests in a pediatric population. PATIENTS AND METHODS: We studied 85 patients (33 boys; mean age: 11.6 +/- 2.9 years). Of them, 56 had a diagnostic history of neurocardiogenic syncope, whereas 29 served as controls. After a negative passive phase, they were randomly assigned to either intravenous isoproterenol or sublingual nitroglycerin, and tilt was continued for 20 minutes. RESULTS: Sensitivity was 0.78 for the isoproterenol test and 0.79 for the nitroglycerin test, but specificity was significantly higher for isoproterenol test compared with nitroglycerin test. In patients with a positive test, the duration of the recovery period was significantly longer after nitroglycerin (8.4 +/- 2.7 minutes) than after isoproterenol (5.1 +/- 1.6 minutes). CONCLUSIONS: Nitroglycerin- and isoproterenol-augmented tilt tests are associated with equal sensitivity in the diagnosis of neurocardiogenic syncope in children and adolescents. However, nitroglycerin results in more false-positive tests and produces more prolonged vasovagal symptoms. Our data do not support the routine use of nitroglycerin in the evaluation of syncope in this age group. Pediatrics

Background: Only limited data exist regarding the long-term efficacy of beta-brachytherapy (beta-VBT) in routine clinical practice and the impact of the prolonged (> 6 months) combined antiplatelet therapy after beta-VBT. Our aim is to examine the long-term clinical efficacy of routine beta brachytherapy (beta-VBT) followed by indefinite administration of combined antiplatelet therapy in patients at high restenotic risk. Methods: Sixty-one patients with 65 lesions [de novo: 41, in-stent restenotic (ISR): 24] underwent intracoronary beta-VBT and were followed prospectively. All patients received indefinite administration of aspirin and clopidogrel, underwent routine angiography 6 months later and were followed-up clinically for 43.7 months (range: 32 to 52 months). Results: Acute success was achieved in 60/61 (98.4%) patients. Lesion length was 36.1 (+/- 17.6) mm for the de novo and 22.0 (+/- 9.8) mm for the ISR (p=0.001). Stems were implanted in 35/41 de novo and 7/24 ISR lesions (p < 0.01). Six-month binary restenosis after successful beta-VBT was 35.9% (23/64). During follow-up patients with de-novo lesions who received a new stent during index procedure had a higher incidence of major cardiac events than patients with ISR lesions without a new stent (log rank test, p=0.02). Acute and late thrombotic events were reported at 6 patients, all with de novo lesions and stent implantation. Conclusions: Beta-VBT plus stenting in de novo lesions is related to an unacceptable high rate of thrombotic complications and clinical restenosis despite prolonged administration of combined antiplatelet therapy. Brachytherapy remains a reasonable option for patients with ISR lesions until full data from large randomized trials comparing drug eluting stents with brachytherapy are available. (c) 2006 Elsevier Ireland Ltd. All rights reserved. Int J Cardiol

OBJECTIVES: To determine the impact of the level of kidney function on the extended (>5 years) long-term clinical course of patients undergoing percutaneous coronary intervention (PCI). BACKGROUND: Chronic kidney disease (CKD) has been significantly associated with an increased in-hospital and 1-year mortality following PCI. METHODS: In this single-centre retrospective study, glomerular filtration rate (GFR) at baseline was estimated in 371 patients not on dialysis, who underwent successful PCI between mid-1995 and mid-1999. Baseline demographic and angiographic characteristics, and long-term major adverse cardiac events and symptoms were compared for patients with GFR > or =60 ml/min/1.73 m(2) (normal or mildly impaired renal function) and GFR > or = 60 ml/ min/1.73 m(2) (CKD). The independent effect of GFR, modelled both as a categorical and a continuous variable, on long-term clinical outcomes was also investigated using multivariate Cox regression analysis. RESULTS: Nine-year all-cause and cardiac mortality rates were significantly higher in the CKD group (45.9% vs. 10.6%, P < 0.0001 and 35.4% vs. 7.1%, P < 0.0001 respectively), while there was no difference in the repeat revascularization (P = 0.27) and nonfatal Q-wave myocardial infarction (P = 0.74) rates. Multivariate analysis demonstrated an independent impact of the level of GFR on long-term mortality; adjusted 9-year all-cause and cardiac mortality increased by approximately 16% and 11%, respectively for a decrease of GFR from 120 to 60 ml/min/1.73 m(2) and by approximately 14% and 9%, respectively for a decrease of GFR from 60 to 30 ml/min/1.73 m(2). CONCLUSIONS: The level of renal function is a strong determinant of long-term all-cause and cardiac mortality after successful PCI. Catheter Cardiovasc Interv

We report a patient with coronary dilatation 10 weeks after paclitaxel-eluting stent implantation in the right coronary artery (RCA). Coronary angiography demonstrated a double-locular lumen dilatation in the body of the stented segment of the RCA, and intravascular ultrasound interrogation revealed the corresponding region with evidence of tissue regression behind the stent struts, incomplete stent apposition, and lumen enlargement. After three-dimensionally (3D) reconstructing the RCA, we applied computational fluid dynamics to the 3D RCA model, representing the lumen of the artery at the moment of stent implantation, and investigated the correlation of both neointimal thickness and tissue regression depth with shear stress in the stent. Neointimal thickness was found to be inversely related to shear stress, but there was no significant association of tissue regression depth with shear stress. Post-procedural stent malapposition, thrombus dissolution, and less possibly, a localized hypersensitivity reaction are potential mechanisms for the lumen enlargement in this case. Heart Vessels

Experimental and clinical data suggest that stents eluting antiproliferative agents can be used for the prevention of in-stent restenosis. Here we investigate in vitro the antiproliferative and apoptotic effect of D-24851 and evaluate the safety and efficacy of D-24851-eluting polymer-coated stents in a rabbit restenosis model (n = 53). Uncoated stents (n = 6), poly (DL: -lactide-co-glycolide) (PLGA)-coated stents (n = 7), and PLGA-coated stents loaded with 0.08 +/- 0.0025 microM (31 +/- 1 mug; low dose; n = 7), 0.55 +/- 0.02 microM (216 +/- 8 mug; high dose; n = 6), and 4.55 +/- 0.1 microM (1774 +/- 39 mug; extreme dose; n = 5) of D-24851 were randomly implanted in New Zealand rabbit right iliac arteries and the animals were sacrificed after 28 days for histomorphometric analysis. For the assessment of endothelial regrowth in 90 days, 12 rabbits were subjected to PLGA-coated (n = 3), low-dose (n = 3), high-dose (n = 3), and extreme-dose (n = 3) stent implantation. In vitro studies revealed that D-24851 exerts its growth inhibitory effects via inhibition of proliferation and induction of apoptosis without increasing the expression of heat shock protein-70, a cytoprotective and antiapoptotic protein. Treatment with low-dose D-24851 stents was associated with a significant reduction in neointimal area and percentage stenosis only compared with bare metal stents (38% [P = 0.029] and 35% [P = 0.003] reduction, respectively). Suboptimal healing, however, was observed in all groups of D-24851-loaded stents in 90 days in comparison with PLGA-coated stents. We conclude that low-dose D-24851-eluting polymer-coated stents significantly inhibit neointimal hyperplasia at 28 days through inhibition of proliferation and enhancement of apoptosis. In view of the suboptimal re-endothelialization, longer-term studies are needed in order to establish whether the inhibition of intimal growth is maintained. Cardiovasc Intervent Radiol

We report for the first time a real three-dimensional reconstruction of the left main coronary artery, left main bifurcation, left anterior descending coronary artery and left circumflex coronary artery using biplane angiography and intravascular ultrasound imaging in a patient with a proximal stenosis in the left anterior descending coronary artery. By using computational fluid dynamics in the three-dimensional luminal model we computed endothelial shear stress, while plaque thickness was calculated as the difference between the three-dimensional lumen and outer vessel wall; plaque thickness was found to be inversely related to endothelial shear stress in the left main coronary artery and bifurcation. The application of our methodology for real three-dimensional reconstruction of the left main coronary artery and bifurcation is useful for investigating the relationship of hemodynamic parameters with plaque thickness in this critical coronary region. (c) 2006 Elsevier Ireland Ltd. All rights reserved. Int J Cardiol

In this work, the dynamic response of the sinoatrial node (SAN), the natural pacemaker of the heart, to short external stimuli is investigated using the Zhang et al. model. The model equations are solved twice for the central cell and for the peripheral cell. A short current pulse is applied to reset the spontaneous rhythmic activity of the single sinoatrial node cell. Depending on the stimulus timing either a delay or an advance in the occurrence of next action potential is produced. This resetting behavior is quantified in terms of phase transition curves (PTCs) for short electrical current pulses of varying amplitude which span the whole period. For low stimulus amplitudes the transition from advance to delay is smooth, while at higher amplitudes abrupt changes and discontinuities are observed in PTCs. Such discontinuities reveal critical stimuli, the application of which can result in annihilation of activity in central SAN cells. The detailed analysis of the ionic mechanisms involved in its resetting behavior of sinoatrial node cell models provides new insight into the dynamics and physiology of excitation of the sinoatrial node of the heart. (c) 2005 Elsevier Ltd. All rights reserved. Comput Biol Med

Apoptosis has been suggested to have an important role in the pathogenesis of restenosis in addition to cell migration and proliferation. The aim of the present study was to investigate in an experimental in vivo model the occurrence of apoptosis postangioplasty and its relation to bcl-2 and peroxynitrite detection. Eighteen hypercholesterolemic rabbits underwent transluminal angioplasty of the right iliac artery. The rabbits were sacrificed on the 1st, 2nd, 3rd, 7th, 15th, and 28th day postangioplasty (3 animals per time point) and both the angioplasted and non-injured arteries were studied. Apoptosis was assessed by the terminal uridine nick-end labeling method (TUNEL). Bcl-2 and peroxynitrite were detected by immunochemistry using anti-bcl-2 and anti-nitrotyrosine antibodies. In the angioplasted arteries the number of apoptotic cells was

Objective: In the current work we propose a methodology for the automated creation of fuzzy expert systems, applied in ischaemic and arrhythmic beat classification. Methods: The proposed methodology automatically creates a fuzzy expert system from an initial training dataset. The approach consists of three stages: (a) extraction of a crisp set of rules from a decision tree induced from the training dataset, (b) transformation of the crisp set of rules into a fuzzy model and (c) optimization of the fuzzy model's parameters using global optimization. Material: The above methodology is employed in order to create fuzzy expert systems for ischaemic and arrhythmic beat classification in ECG recordings. The fuzzy expert system for ischaemic beat detection is evaluated in a cardiac beat dataset that was constructed using recordings from the European Society of Cardiology ST-T database. The arrhythmic beat classification fuzzy expert system is evaluated using the MIT-BIH arrhythmia database. Results: The fuzzy expert system for ischaemic beat classification reported 91% sensitivity and 92% specificity. The arrhythmic beat classification fuzzy expert system reported 96% average sensitivity and 99% average specificity for all categories. Conclusion: The proposed methodology provides high accuracy and the ability to interpret the decisions made. The fuzzy expert systems for ischaemic and arrhythmic beat classification compare well with previously reported results, indicating that they could be part of an overall clinical system for ECG analysis and diagnosis. (C) 2007 Elsevier B.V. All rights reserved. Artif Intell Med

In this paper, we use a one-dimensional model of the rabbit sinoatrial node (SAN), and we investigate the response of the model to hyperpolarizing and depolarizing stimulus. Depending on the stimulus timing, either a delay or an advance in the occurrence of next action potential is produced. This resetting behavior of the model is quantified in terms of phase transition curves (PTCs) for short electrical current pulses of varying amplitude which span the whole period. The main focus of this paper is: to compare the dynamic properties of the spatially extended system and the single cell model. The detailed analysis of the results provides new insights in the understanding of the transition from the theoretical single cell models to the spatially extended systems. Ieee Transactions on Biomedical Engineering

We describe herein the case of a 49-year-old female patient with pulmonary sarcoidosis (stage II) with cardiac manifestation. This consisted of systolic dysfunction without dilatation of the left ventricle and severe mitral insufficiency, possibly due to thinning of the posteromedial left ventricular free wall, based on our echocardiographic observations. Heart Vessels

Currently, an automated methodology based on association rules is presented for the detection of ischemic beats in long duration electrocardiographic (ECG) recordings. The proposed approach consists of three stages. 1) Preprocessing: Noise is removed and all the necessary ECG features are extracted. 2) Discretization: The continuous valued features are transformed to categorical. 3) Classification: An association rule extraction algorithm is utilized and a rule-based classification model is created. According to the proposed methodology, electrocardiogram (ECG) features extracted from the ST segment and the T-wave, as well as the patient's age, were used as inputs. The output was the classification of the beat as ischemic or not. Various algorithms were tested both for discretization and for classification using association rules. To evaluate the methodology, a cardiac beat dataset was constructed using several recordings of the European Society of Cardiology ST-T database. The obtained sensitivity (Se) and specificity (Sp) was 87% and 93%, respectively. The proposed methodology combines high accuracy with the ability to provide interpretation for the decisions made, since it is based on a set of association rules. Ieee Transactions on Biomedical Engineering

Polytetrafluoroethylene-covered stents (PCS) were recently proposed as a new modality mainly for the treatment of saphenous vein graft lesions, but restenosis occurring principally at the edges restricted their clinical use in the management of coronary aneurysms and perforations.Aims: To investigate the safety and effectiveness of the overlapping implantation of drug-eluting stents (DES) with PCS in clinical scenarios where the latter are indicated.Methods: Since April 2002, when DES were introduced in clinical practice, 14 consecutive patients were -treated with overlapping implantation of PCS with DES in 3 centres. Seven patients were treated for coronary aneurysms, 5 for coronary perforations and 2 for branch occlusion. The incidence of any major adverse cardiac events defined as death, myocardial infarction (MI), and target vessel revascularisation (TVR) was retrospectively evaluated. A control angiography was available in 13 patients, and quantitative coronary angiography was performed before and after the intervention and at follow-up to evaluate restenosis rate and late loss.Results: At a mean clinical follow-up of 21.9 months there were no deaths or MI's, while one patient with occlusive restenosis underwent successful TVR (7.7%). At angiographic follow-up (mean: 9.7 months) there was one patient with restenosis (7.7%), who had a total occlusion. After excluding the patient with the occlusive restenosis mean diameter stenosis was 22.4+/-11.7% and late loss was 0.18+/-0.35 mm at follow-up. No early or late stent thrombosis occurred.Conclusion: Overlapping implantation of PCS with DES seems to be a safe and effective therapeutic modality demonstrating a low incidence of clinical and angiographic restenosis. EuroIntervention

The development of pressure monitoring guide-wires has facilitated the measurements of coronary pressures distal to a stenosis. The ratio of the distal coronary and aortic pressures (P(d)/P(a)) measured during maximal hyperaemia is a useful index for diagnosis and monitoring the treatment of patients with coronary artery disease and for guiding percutaneous coronary intervention. However, the role of coronary pressure measurements in post- myocardial infarction (MI) patients is not well established. Coronary pressure measurements should be used with caution during the acute phase of MI due to serious micro-vascular impairment. The hyperaemic pressure P(d)/P(a) ratio can identify ischaemic myocardial territories in patients with recent MI. Theoretically, coronary pressure measurements may be of value in predicting myocardial recovery after revascularization in post-MI patients with a moderate stenosis of the infarct-related artery and without angiographically evident collaterals. Acute Card Care

Thoracic and abdominal aortic endovascular procedures as alternatives to aortic reoperations were studied in three different cases. An anastomotic aneurysm after previous thoracic aortic graft for coarctation, a second-stage elephant trunk repair (descending thoracic aortic aneurysm), and a secondary aneurysm proximal to a previous abdominal aortic graft were successfully treated with endovascular stent-grafts. During the follow-up period no lethal events or major aortic or graft-related complications were observed, except a type II endoleak in the anastomotic aortic aneurysm case. An endovascular stent-graft can be safely deployed into a previously implanted vascular graft, avoiding repeat surgery. Cardiovasc Intervent Radiol

The purpose of this article is to report the initial experience with endovascular repair of thoracic aortic disease in a single tertiary vascular unit in northwestern Greece. Between 2003 and 2005, 16 patients were treated with endovascular techniques for various pathologies of the descending thoracic aorta. Twelve patients were treated electively and four emergently. Operative and follow-up data for a mean time of 18.4 months were retrospectively collected and analyzed. Primary technical success was obtained in 14 (87.5%) cases. No early or late deaths occurred, and there was no major operation-related complication. No paraplegia was observed in our patients. Stent graft-related complications occurred in 18.75% (one type 2 and two type 3 endoleaks), but they all had a favorable outcome. No further problems have been reported in any of our patients. Endovascular stent graft repair for diseases of the thoracic aorta seems to be a promising alternative to open surgery, especially for high-risk patients. Long-term results are needed to confirm the early benefit of this treatment option with regard to morbidity and mortality rates. The potential of this technique to be applicable even in relatively small, tertiary vascular centers might be of great benefit to patients. Vascular

The aim of this study is to describe a new method for the three-dimensional reconstruction of coronary arteries and its quantitative validation. Our approach is based on the fusion of the data provided by intravascular ultrasound images (IVUS) and biplane angiographies. A specific segmentation algorithm is used for the detection of the regions of interest in intravascular ultrasound images. A new methodology is also introduced for the accurate extraction of the catheter path. In detail, a cubic B-spline is used for approximating the catheter path in each biplane projection. Each B-spline Curve is Swept along the normal direction of its X-ray angiographic plane forming a surface. The intersection of the two surfaces is a 3D curve, which represents the reconstructed path. The detected regions of interest in the IVUS images are placed perpendicularly onto the path and their relative axial twist is computed using the sequential triangulation algorithm. Then, ail efficient algorithm is applied to estimate the absolute orientation of the first IVUS frame. In order to obtain 3D visualization the commercial package Geomagic Studio 4.0 is used. The performance of the proposed method is assessed using a validation methodology which addresses the separate validation of each step followed for obtaining the coronary reconstruction. The performance of the segmentation algorithm was examined in 80 IVUS images. The reliability of the path extraction method was studied in vitro using a metal wire model and in vivo in a dataset of I I patients. The performance of the sequential triangulation algorithm was tested in two gutter models and in the coronary arteries (marked with metal clips) of six cadaveric sheep hearts. Finally, the accuracy in the estimation of the first IVUS frame absolute orientation was examined ill the same set of cadaveric sheep hearts. The obtained results demonstrate that the proposed reconstruction method is reliable and capable of depicting the morphology of coronary arteries. (C) 2005 Elsevier Ltd. All rights reserved. Computerized Medical Imaging and Graphics

Objectives: This study reports the 9-year clinical outcome of 409 consecutive patients, who underwent coronary angioplasty with provisional stenting during the years 1995 to 1999 in the University Hospital of Northwestern Greece. Background: Despite the rapid changes of interventional cardiology, long-term follow-up studies are useful for identifying its limitations and indicating future changes.Methods: Baseline characteristics and information on survival, major cardiac events and symptoms were retrospectively obtained from medical records or telephone contact. Patient survival rates were calculated and predictive factors for survival and cardiac events were identified. Results: Follow-up information was obtained in 403 patients (98.5%). Three hundred and thirty-one patients (82%) were alive with 150 (45%) being symptom free. The cumulative 5- and 9-year survival rates were 87% and 78% respectively, and the corresponding survival free from major adverse cardiac events was 65% and 55%. Independent factors affecting survival were age>65 years, diabetes, hypertension, multivessel disease and ejection fraction

BACKGROUND: We have previously reported significant benefits of using enoxaparin, compared to tinzaparin, in the 7- and 30-day incidence of the composite triple end point of death, myocardial infarction (MI), or recurrent angina in patients with non-ST-segment elevation acute coronary syndromes (NSTACS). In the present study, we aimed to determine whether the observed benefits of enoxaparin were maintained beyond the early phase and report the results of the 6-m follow-up of patients in the EVET study. METHODS: We recruited 438 patients with NSTACS. All patients received oral aspirin and were randomized to also receive enoxaparin, 100 IU/kg subcutaneously twice daily (equivalent to 1 mg/kg twice daily; n = 220), or tinzaparin, 175 IU/kg subcutaneously once daily (n = 218), for up to 7 days. RESULTS: At 6 m, the incidence of the composite triple end point of death, MI, or recurrent angina was lower among patients receiving enoxaparin compared to those receiving tinzaparin (25.5% vs 44.0%, P < .001). A lower incidence of the secondary composite end point of death or MI was also found in the enoxaparin group compared to tinzaparin group (2.7% vs 6.9%, P = .046). The need for revascularization procedures was also lower in the enoxaparin group compared to tinzaparin group (23.2% vs 37.2%, P = .002). CONCLUSIONS: In patients with NSTACS, enoxaparin significantly reduced the rates of recurrent ischemic events and therapeutic procedures in the short term, with sustained benefit at 6 m compared to tinzaparin. Am Heart J

Coronary artery ectasia (CAE) is an uncommon form of coronary artery disease. It has been reported in association with a variety of pathological conditions, such as isolated congenital heart disease and Kawasaki disease. CAE is more relevant in young adults with multiple predisposing risk factors, especially familial hypercholesterolemia, and is usually considered a form of atherosclerotic coronary artery disease. A case of CAE is reported with familial hypercholesterolemia and diffuse ectasia of the coronary vessels in association with anomalous origin of the left circumflex coronary artery, which lacked ectatic segments. This combination has not been reported previously. Angiology

Macrophages interact with modified lipoproteins and alter their functional status. In this study, the effects of the adrenergic agents adrenaline, isoproterenol, and dobutamine on macrophages activated with acetylated low-density lipoprotein were tested. The aim of this investigation was to determine whether adrenergic agents influence biologically significant functions of these cells in an in vitro model of macrophage-lipoprotein acute interaction. Rat peritoneal macrophages were incubated with acetylated low-density lipoprotein for 16 h, with or without adrenergic agents. Hydrogen peroxide and nitric oxide production and acid phosphatase activities in the supernatant and cell lysate were assayed. Adrenaline and isoproterenol inhibited the production of hydrogen peroxide, stimulated the production of nitric oxide, and increased the extracellular activity of acid phosphatase in the lipoprotein-activated cells. Dobutamine increased the extracellular, but decreased the intracellular acid phosphatase activity. Adrenaline and dobutamine also produced changes in the cell size and nuclear morphology of the macrophages. Macrophages are activated in vitro by acetylated low-density lipoprotein, and their functions and morphology are modified under the influence of adrenergic agents. Certain effects could be attributed to changes in cyclic AMP levels. Pathol Res Pract

Eur Heart J

Hellenic J Cardiol

Objective: To investigate the impact of BiodivYsio dexamethazone-eluting stent versus BiodivYsio stent on the 12-month outcomes after revascularisation of patients with single vessel coronary artery disease.Methods: From March 2003 to February 2004, 102 patients with non-ST elevation acute coronary syndromes, angina or silent ischemia after recent ST elevation myocardial infarction (

Evidence for the role of lipoprotein(a) (Lp[a]) in atherosclerosis and thrombosis has considerably increased over the past few years. Therefore, Lp(a) is currently classified as an emerging lipid risk factor for cardiovascular disease. High Lp(a) plasma levels carried in particles with small-sized apolipoprotein(a) isoforms are associated with preclinical vascular changes, cardiovascular disease and the mode of presentation of coronary artery disease (acute coronary syndromes). However, randomized clinical trials with an emphasis on agents that specifically lower plasma Lp(a) do not exist. At present, screening for increases in Lp(a) in the general population is not recommended. The measurement of Lp(a) may be of value in individuals with an increased risk of cardiovascular disease, particularly in patients with high low-density lipoprotein cholesterol plasma levels, since a high Lp(a) concentration in such subjects further increases the risk of coronary heart disease. Future Cardiol

Hellenic J Cardiol

Eur Heart J

The aim of this works was to evaluate a new semi-automated intravascular ultrasound (IVUS) border detection method. The method was used to identify the lumen and the external elastic membrane or the borders of stents in 80 IVUS images randomly selected from 10 consecutive human coronary arteries. These semi-automated results were compared with observations of two experts. Several indices in each case were obtained in order fully to evaluate the method. The time required for identification of the borders was also recorded. The interobserver variability of the method ranged from 1.21% to 5.61%, the correlation coefficient from 0.98 to 0.99, the slope was close to unity (0.94-1.03), the y intercept close to zero and the Williams index value was close to unity (range 0.67-0.91). The time (mean +/- SD) required for the method to identify the borders of the different vessel layers for the whole IVUS sequence was 5.2 +/- 0.2 min. The results demonstrate that the method is reliable and capable of identifying rapidly and accurately the different vessel layers depicted in IVUS images. British Journal of Radiology

CONTEXT: Women with polycystic ovary syndrome (PCOS) may be at increased risk for cardiovascular disease. Endothelial dysfunction is an early marker of atherosclerosis. OBJECTIVES: The objectives of this study were to 1) compare endothelial function in young women with PCOS and regularly menstruating control women, and 2) to identify the determinants of endothelial function and investigate its relationship with body mass index in women with PCOS. DESIGN: This was a cross-sectional study. SETTING: This study was conducted at a tertiary cardiovascular research center. PATIENTS: Sixty-two young women with PCOS (mean age, 22.7 yr) and 17 control women, matched as a group for age and body mass index, were studied. Twenty-three women with PCOS were lean, 21 were overweight, and 18 were obese. MAIN OUTCOME MEASURES: Endothelium-dependent and -independent vascular function was assessed by measuring flow-mediated dilation (FMD) and nitrate-mediated dilation in the brachial artery (diameter change during hand hyperemia and after sublingual glyceryl trinitrate administration, respectively). RESULTS: FMD and nitrate-mediated dilation were significantly lower in PCOS than in control women (reduced by approximately 50 and 25%, respectively; both P < 0.0005). Insulin resistance, total testosterone, and total cholesterol were independent predictors of FMD, accounting for 21, 10, and 9% of the variance, respectively (P < 0.005 for all). A trend of deterioration in FMD from lean to overweight and obese PCOS women was observed, but differences among groups were not statistically significant. CONCLUSIONS: Women with PCOS have significant endothelial dysfunction at an early age (i.e. early 20s), and largely independent of obesity. This suggests that women with PCOS are at increased risk for early onset cardiovascular disease and may gain particular benefit from measures to improve endothelial function. J Clin Endocrinol Metab

In this paper, we present a method for the automated detection of lumen and media-adventitia border in sequential intravascular ultrasound (IVUS) frames. The method is based on the use of deformable models. The energy function is appropriately modified and minimized using a Hopfield neural network. Proper modifications in the definition of the bias of the neurons have been introduced to incorporate image characteristics. A simulated annealing scheme is included to ensure convergence at a global minimum. The method overcomes distortions in the expected image pattern, due to the presence of calcium, employing a specialized structure of the neural network and boundary correction schemas which are based on a priori knowledge about the vessel geometry. The proposed method is evaluated using sequences of IVUS frames from 18 arterial segments, some of them indicating calcified regions. The obtained results demonstrate that our method is statistically accurate, reproducible, and capable to identify the regions of interest in sequences of IVUS frames. IEEE Trans Inf Technol Biomed

BACKGROUND: Macrophages that uptake modified lipoproteins are activated and may initially behave as endotoxin-stimulated macrophages. This study was undertaken in order to determine whether signal transduction pathways controlling endotoxin-mediated activation may also influence the lipoprotein-mediated activation of macrophages. MATERIALS AND METHODS: Rat peritoneal macrophages were incubated for 16 hours with acetylated low-density lipoprotein and certain agents that modify the phosphoinositide/calcium- and cyclic AMP-mediated pathways, such as 2-[4-morpholinyl]-8-phenyl-1[4H]-benzopyran-4-one (LY-294002), autocamtide 2-related inhibitory peptide (AIP), N-(2-[p-bromocinnamylamino]-ethyl)-5-isoquinolinesulfonamide hydrochloride (H-89) and actinomycin D. The production of nitric oxide and the intracellular and extracellular activities of acid phosphatase were assayed. RESULTS: Macrophages incubated with acetylated low-density lipoprotein showed an increased production of nitric oxide and intracellular acid phosphatase activity as compared to their controls. LY-294002, AIP and H-89 caused a significant decrease in nitric oxide production and intracellular acid phosphatase activity. Actinomycin D had similar effects. AIP and actinomycin also significantly increased extracellular acid phosphatase activity. CONCLUSION: The activation of peritoneal macrophages by acetylated low-density lipoprotein was similar to the activation by endotoxin, as expressed by the nitric oxide production and acid phosphatase intracellular activity; agents controlling the phosphoinositide/calcium- and cyclic AMP-mediated pathways in endotoxin-activated macrophages also influence the acetylated low-density lipoprotein-activated macrophages. In Vivo

We evaluated the extent of agreement among three algorithms used for the localization of accessory pathways in patients with overt preexcitation. By the use of one algorithm, three independent couples of observers localized the accessory pathway in 95 consecutive patients showing overt preexcitation in the 12-lead surface electrocardiogram. We defined the following regions: Left atrioventricular ring (LAVR), Right atrioventricular ring (RAVR), Left lateral/left anterolateral (LL/LAL), Left posterior/left posterolateral (LP/LPL), Left posteroseptal (LPS), Right midseptal (RMS), Right posteroseptal (RPS), Right posterior/right posterolateral (RP/RPL), Right lateral/right anterolateral (RL/RAL), and Right anterior/right anteroseptal (RA/RAS). The extent of agreement in each region was evaluated and compared with the expected one, as calculated from the reported. The extent of agreement was as expected: (1) high in the regions LAVR, RAVR, LL/LPS and (2) limited in the regions LPS, RPS, and (3) clearly lower than expected in the regions LP/LPL, RA/RAS, RMS, RL/RAL. In cases with total or partial disagreement, the number of electrocardiograms with duration of QRS complex smaller than 120 ms was greater than in cases with total agreement (30/46 vs 22/50, P < 0.05). The observed agreement among algorithms is clearly lower than the expected one. Minimal preexcitation, limited number of patients, and arbitrarily defined regions were possibly the reasons for some unexpected results. Pacing Clin Electrophysiol

In this paper, we present a method for the automated detection of lumen and media-adventitia border in sequential intravascular ultrasound (IVUS) frames. The method is based on the use of deformable models. The energy function is appropriately modified and minimized using a Hopfield neural network. Proper modifications in the definition of the bias of the neurons have been introduced to incorporate image characteristics. A simulated annealing scheme is included to ensure convergence at a global minimum. The method overcomes distortions in the expected image pattern, due to the presence of calcium, employing a specialized structure of the neural network and boundary correction schemas which are based on a priori knowledge about the vessel geometry. The proposed method is evaluated using sequences of IVUS frames from 18 arterial segments, some of them indicating calcified regions. The obtained results demonstrate that our method is statistically accurate, reproducible, and capable to identify the regions of interest in sequences of IVUS frames. Ieee Transactions on Information Technology in Biomedicine

Normal menopause is associated with vascular endothelial dysfunction, an early stage of atherosclerosis. The effect of premature ovarian failure ( or premature menopause) on endothelial function in young women is unknown. Endothelial function was assessed in 18 women with premature ovarian failure before and after 6 months of hormone therapy and was compared with the endothelial function of 20 age- and body mass index-matched premenopausal women. Brachial artery diameter was measured both during hyperemia ( an index of endothelium-dependent vasodilation) and in response to glyceryl trinitrate ( an index of endothelium-independent vasodilation). Flow-mediated dilation was significantly lower in women with premature ovarian failure at baseline ( increase in brachial artery diameter during hyperemia by 3.06 +/- 4.33%) than in control women ( increase by 8.84 +/- 2.15%; P < 0.0005). Glyceryl trinitrate-induced vasodilation did not differ between the groups. After hormone therapy for 6 months, flow-mediated dilation was improved in women with premature ovarian failure, increasing by more than 2-fold (7.41 +/- 3.86%; P < 0.005 compared with pretreatment) and reaching normal values ( P not significant compared with control women). Glyceryl trinitrate-induced vasodilation did not change after treatment in women with premature ovarian failure. Young women with premature ovarian failure have significant vascular endothelial dysfunction. Early onset of endothelial dysfunction associated with sex steroid deficiency may contribute to the increased risk of cardiovascular disease and mortality in young women with premature ovarian failure. Hormone therapy restores endothelial function within 6 months of treatment. Journal of Clinical Endocrinology & Metabolism

Three cases of local thrombolysis in the treatment of acute lower limb ischemia complicating the utilization of the Duett sealing device are presented. Routine usage of several vascular closure devices after cardiac catheterization and percutaneous coronary intervention (PCI) has been adopted in our institution during the last 3 years (September 1999 to April 2003). The Duett closure device has been used in 420 patients (post-coronary angiography, 359; post-PCI, 61). Three patients (0.7%) demonstrated acute leg ischemia used by inadvertent intravascular administration of the sealing material related to this device. All three were treated successfully by catheter-directed local thromolysis (tissue plasminogen activator 5 mg bolus followed initially by 1 mg/hr and consequently by 0.5-1.0 mg/hr depending upon the development of significant hematoma and lasting for 24 hr). In conclusion, interventional treatment using local thrombolysis should be the first-line treatment in acute lower limb ischemia complicating the utilization of the Duett sealing device. Cardiovasc Intervent Radiol

BACKGROUND: Low-molecular weight heparins have different pharmacokinetic and pharmacodynamic characteristics and may vary in efficacy. We compared the efficacy of enoxaparin with that of tinzaparin in the management of non-ST-segment elevation acute coronary syndromes (NSTACS). METHODS: A total of 438 patients with NSTACS were randomized to receive subcutaneous treatment with enoxaparin, 100 IU/kg twice daily (equivalent to 1 mg/kg twice daily; n = 220), or tinzaparin, 175 IU/kg once daily, (n = 218) for as long as 7 days. The primary composite end point was recurrent angina, myocardial infarction (or reinfarction), or death at day 7. Secondary end points were the primary end point at day 30 and the occurrence of individual events at days 7 and 30. RESULTS: The incidence of the primary end point was 12.3% in the enoxaparin group and 21.1% in the tinzaparin group (P =.015). At day 7, the rate of recurrent angina was lower with enoxaparin than with tinzaparin (11.8% vs 19.3%). At day 30, the incidences of the composite end point, recurrent angina, and myocardial infarction were also lower with enoxaparin, 17.7% vs 28.0% (P =.012), 17.3% vs 26.1% and 0.5% vs 2.8%, respectively. The rate of revascularization was lower in the enoxaparin group, 8.6% vs 17.9% (P =.010) at day 7 and 16.4% vs 26.1% (P =.019) at day 30. Rates of bleeding complications were similar in the 2 treatment groups. CONCLUSIONS: This study indicates a benefit of enoxaparin (100 IU/kg twice daily) as compared with tinzaparin (175 IU/kg once daily) in the treatment of patients with NSTACS, which is sustained for at least 30 days. Am Heart J

Atherosclerosis Supplements

An 82-year old man was admitted with acute pulmonary edema. Myocardial ischemia and electrolyte abnormalities were excluded and he responded promptly to frusemide, nitrates and morphine. On admission, the duration of the QRS interval was markedly abnormal at 240 ms with a nonspecific intraventricular conduction defect pattern, of left bundle branch block type. This finding was not present three weeks prior to his admission, and was felt to be the result of drug interaction between propafenone and antineoplastic agents, as evidenced by resolution of the clinical and electrocardiographic picture after discontinuation of these agents. Cardiovasc Drugs Ther