Glucose monitoring by means of an intravenous microdialysis catheter technique

BACKGROUND

Patients with acute coronary syndrome (ACS) and hyperglycemia are at an increased mortality risk. A rapidly obtained optimized glycemic control without inducing hypoglycemia is important. We evaluated the accuracy of a microdialysis catheter (CMA 64 IView, CMA Microdialysis AB, Solna, Sweden) to monitor glucose levels in patients in the coronary care unit (CCU).

METHODS

Fourteen patients admitted to the CCU with ACS (n = 11) or heart failure (n = 3) had a venous microdialysis catheter applied for 3 days. Glucose levels were measured simultaneously in plasma and microdialysis fluid at eight time points for 1 h each day.

RESULTS

The overall congruence between the two measurements of blood glucose was acceptable except in four patients in whom the microdialysis measurements were too low. No obvious relationship between site of the catheter, body composition, blood pressure, diagnosis, or medical treatment and discrepant values was detected.

CONCLUSIONS

These initial experiences are promising and motivate further research to improve the microdialysis technique. In future studies longer periods of recordings should be included to disclose technical problems.

Mouse Rad1 deletion enhances susceptibility for skin tumor development

Background

Cells are constantly exposed to stresses from cellular metabolites as well as environmental genotoxins. DNA damage caused by these genotoxins can be efficiently fixed by DNA repair in cooperation with cell cycle checkpoints. Unrepaired DNA lesions can lead to cell death, gene mutation and cancer. The Rad1 protein, evolutionarily conserved from yeast to humans, exists in cells as monomer as well as a component in the 9-1-1 protein complex. Rad1 plays crucial roles in DNA repair and cell cycle checkpoint control, but its contribution to carcinogenesis is unknown.

Results

To address this question, we constructed mice with a deletion of Mrad1. Matings between heterozygous Mrad1 mutant mice produced Mrad1^+/+ and Mrad1^+/- but no Mrad1^-/- progeny, suggesting the Mrad1 null is embryonic lethal. Mrad1^+/- mice demonstrated no overt abnormalities up to one and half years of age. DMBA-TPA combinational treatment was used to induce tumors on mouse skin. Tumors were larger, more numerous, and appeared earlier on the skin of Mrad1^+/- mice compared to Mrad1^+/+ animals. Keratinocytes isolated from Mrad1^+/- mice had significantly more spontaneous DNA double strand breaks, proliferated slower and had slightly enhanced spontaneous apoptosis than Mrad1^+/+ control cells.

Conclusion

These data suggest that Mrad1 is important for preventing tumor development, probably through maintaining genomic integrity. The effects of heterozygous deletion of Mrad1 on proliferation and apoptosis of keratinocytes is different from those resulted from Mrad9 heterozygous deletion (from our previous study), suggesting that Mrad1 also functions independent of Mrad9 besides its role in the Mrad9-Mrad1-Mhus1 complex in mouse cells.

Working under pressure: coronary arteries and the endothelin system

Endogenous endothelin-1-dependent (ET-1) tone in coronary arteries depends on the balance between ET(A) and ET(B) receptor-mediated effects and on parameters such as receptor distribution and endothelial integrity. Numerous studies highlight the striking functional interactions that exist between nitric oxide (NO) and ET-1 in the regulation of vascular tone. Many of the cardiovascular complications associated with cardiovascular risk factors and aging are initially attributable, at least in part, to endothelial dysfunction characterized by a dysregulation between NO and ET-1. The contribution of the imbalance between smooth muscle ET(A/B) and endothelial ET(B) receptors to this process is poorly understood. An increased contribution of ET-1 that is associated with a proportional decrease in that of NO accompanies the development of coronary endothelial dysfunction, coronary vasospasm, and atherosclerosis. These data form the basis for the rationale of testing therapeutic approaches counteracting ET-1-induced cardiovascular dysfunction. It remains to be determined whether the beneficial role of endothelial ET(B) receptors declines with age and risk factors for cardiovascular diseases, revealing smooth muscle ET(B) receptors with proconstricting and proinflammatory activities.

Outcomes in diabetic versus nondiabetic patients who present with acute myocardial infarction and are treated with drug-eluting stents

Patients with diabetes mellitus (DM) are at a greater risk of mortality and cardiovascular events after percutaneous coronary intervention than those without DM. We aimed to determine whether differences exist in the long-term mortality of patients with versus without DM who present with acute myocardial infarction and receive drug-eluting stents. Data were collected on 161 patients with and 395 without DM referred for primary percutaneous coronary intervention for acute myocardial infarction and treated with drug-eluting stents. The patients with cardiac arrest or cardiogenic shock were excluded. The 1-year major cardiac event (MACE) rates, defined as death, Q-wave myocardial infarction, or target lesion revascularization, were compared between the 2 groups. The patients with DM were sicker at baseline. The MACE rates at 1 year were significantly increased in those with DM compared to those without DM. This was primarily driven by all-cause mortality. No differences in Q-wave myocardial infarction, target lesion revascularization, stent thrombosis, type of drug-eluting stents used, or procedure-related renal failure were seen. No differences were found in death or MACE rates at 1 year after adjusting for age, gender, race, systemic hypertension, peripheral artery disease, and a history of chronic renal failure between the 2 groups (weighted log-rank statistic, p = 0.37 and p = 0.37, respectively). In patients presenting with acute myocardial infarction, those with DM were sicker than those without DM. In conclusion, after correction for co-morbid conditions, no difference was seen in the 1-year MACE or death rates between those with and without DM who presented with acute myocardial infarction and were treated with drug-eluting stents.

Modifiable and nonmodifiable risk factors for postoperative delirium after cardiac surgery with cardiopulmonary bypass

OBJECTIVES

Postoperative delirium after cardiac surgery is associated with increased morbidity and mortality as well as prolonged stay in both the intensive care unit and the hospital. The authors sought to identify modifiable risk factors associated with the development of postoperative delirium in elderly patients after elective cardiac surgery in order to be able to design follow-up studies aimed at the prevention of delirium by optimizing perioperative management.

DESIGN

A post hoc analysis of data from patients enrolled in a randomized controlled trial was performed.

SETTING

A single university hospital.

PARTICIPANTS

One hundred thirteen patients aged 65 or older undergoing elective cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

None. MEASUREMENTS AND MAINS RESULTS: Screening for delirium was performed using the Confusion Assessment Method (CAM) on the first 6 postoperative days. A multivariable logistic regression model was developed to identify significant risk factors and to control for confounders. Delirium developed in 35 of 113 patients (30%). The multivariable model showed the maximum value of C-reactive protein measured postoperatively, the dose of fentanyl per kilogram of body weight administered intraoperatively, and the duration of mechanical ventilation to be independently associated with delirium.

CONCLUSIONS

In this post hoc analysis, larger doses of fentanyl administered intraoperatively and longer duration of mechanical ventilation were associated with postoperative delirium in the elderly after cardiac surgery. Prospective randomized trials should be performed to test the hypotheses that a reduced dose of fentanyl administered intraoperatively, the use of a different opioid, or weaning protocols aimed at early extubation prevent delirium in these patients.

Medical mystery: an unusual cause of anaemia

An 82-year-old Indian man presented with a month's history of increasing lethargy, shortness of breath and 2 kg weight loss. No significant past illness was elicited, specifically no history of change in bowel habit, malaena, haematemesis, fever, abdominal or chest pain. At admission, he was on oral iron therapy only and was a non-smoker who rarely drank alcohol. On examination he was pale, haemodynamically stable, with normal cardiorespiratory, abdominal and digital rectal examinations.

Factors that affect mass transport from drug eluting stents into the artery wall

Coronary artery disease can be treated by implanting a stent into the blocked region of an artery, thus enabling blood perfusion to distal vessels. Minimally invasive procedures of this nature often result in damage to the arterial tissue culminating in the re-blocking of the vessel. In an effort to alleviate this phenomenon, known as restenosis, drug eluting stents were developed. They are similar in composition to a bare metal stent but encompass a coating with therapeutic agents designed to reduce the overly aggressive healing response that contributes to restenosis. There are many variables that can influence the effectiveness of these therapeutic drugs being transported from the stent coating to and within the artery wall, many of which have been analysed and documented by researchers. However, the physical deformation of the artery substructure due to stent expansion, and its influence on a drugs ability to diffuse evenly within the artery wall have been lacking in published work to date. The paper highlights previous approaches adopted by researchers and proposes the addition of porous artery wall deformation to increase model accuracy.

Intravascular mechanical cavopulmonary assistance for patients with failing Fontan physiology

To provide a viable bridge-to-transplant, bridge-to-recovery, or bridge-to-surgical reconstruction for patients with failing Fontan physiology, we are developing a collapsible, percutaneously inserted, magnetically levitated axial flow blood pump to support the cavopulmonary circulation in adolescent and adult patients. This unique blood pump will augment pressure and thus flow in the inferior vena cava through the lungs and ameliorate the poor hemodynamics associated with the univentricular circulation. Computational fluid dynamics analyses were performed to create the design of the impeller, the protective cage of filaments, and the set of diffuser blades for our axial flow blood pump. These analyses included the generation of pressure-flow characteristics, scalar stress estimations, and blood damage indexes. A quasi-steady analysis of the diffuser rotation was also completed and indicated an optimal diffuser rotational orientation of approximately 12 degrees. The numerical predictions of the pump performance demonstrated a pressure generation of 2-25 mm Hg for 1-7 L/min over 3000-8000 rpm. Scalar stress values were less than 200 Pa, and fluid residence times were found to be within acceptable ranges being less than 0.25 s. The maximum blood damage index was calculated to be 0.068%. These results support the continued design and development of this cavopulmonary assist device, building upon previous numerical work and experimental prototype testing.

Impact of intravascular ultrasound guidance in patients with acute myocardial infarction undergoing percutaneous coronary intervention

OBJECTIVES

The aim of this study was to examine the utility of routine intravascular ultrasound (IVUS) guidance in patients with acute myocardial infarction (MI) undergoing percutaneous coronary intervention (PCI) with stent implantation.

BACKGROUND

Stent thrombosis (ST) is a serious complication of PCI with stent implantation for patients presenting with acute MI. Mechanical factors such as incomplete stent expansion and smaller stent diameters are known to correlate with ST and restenosis. IVUS guidance for stent deployment is reported to reduce these events in stable patients.

METHODS

We analyzed a cohort of 905 consecutive patients who underwent primary PCI for acute MI and were discharged alive. The clinical outcomes of 382 patients who underwent IVUS-guided PCI were compared to those of 523 patients who did not. Patients who presented with cardiogenic shock and rescue PCI were excluded. The primary composite endpoint of death, MI, and target lesion revascularization at 1-year follow-up was systematically indexed and a propensity score was performed with regard to the use of IVUS-guided PCI.

RESULTS

Patients undergoing IVUS-guided PCI were older, more diabetic and hypertensive, but presented with less history of previous MI. The severity of coronary artery disease was balanced between both groups. The number of treated lesions and stents used was higher in the IVUS-guided group, with a longer procedural duration. The overall rates of the composite primary outcome were similar (14.5% vs. 14.3%, P = 0.94) as were the rates of definite and probable stent thrombosis at 1 year (2.1% vs. 2.1%, P = 0.99) in the IVUS-guided and no-IVUS groups, respectively. After multivariate and propensity score adjustment, IVUS guidance was not an independent predictor for the primary endpoint.

CONCLUSION

This study does not support the routine use of IVUS guidance for stent deployment in patients who present with acute MI and undergo primary PCI.

Drug-eluting stents: issues of late stent thrombosis

In in-stent restenosis, drug-eluting stents are superior compared with bare metal stents. However, there are concerns about safety because of the reports of increased risk of late and very late stent thrombosis. Stent thrombosis remains a major pitfall in contemporary percutaneous coronary intervention, leading to high rates of death and nonfatal myocardial infarction. A new standardized definition of stent thrombosis was established to provide consistency in the reporting of this complication and to enable accurate and reliable data to be described for both types of stents, bare metal and drug-eluting. This new consensual definition reflects a large amount of new data reported in the literature. New generations of drug-eluting stents with novel polymers, antiproliferative drugs, and improved platforms are now approved and available for use. In this article, the authors provide a critical appraisal of the safety of different drug-eluting stents based on the published clinical data focusing on late and very late stent thrombosis.

Future Developments in Nonsurgical Epicardial Therapies

The unique anatomic position of the pericardium in juxtaposition to central cardiac structures enables it to serve as the ideal vantage point for the delivery of novel cardiovascular therapies. Development of new tools to permit delivery of therapy in the closed pericardial space holds promise for near-surgical access to the heart, without open surgical morbidity. Early observations raise hope for the availability of epicardial leads to enhance cardiac resynchronization therapy designed for subxiphoid nonsurgical percutaneous delivery. Emerging technologies for left atrial appendage ligation may offer new strategies for preventing stroke.

Rotational atherectomy of a complex, highly calcified left anterior descending artery lesion

Rotational atherectomy (RA) is an advanced coronary debulking technique, often used in cases, where traditional percutaneous coronary intervention (PCI) methods (e.g. balloon predilatation, use of cutting balloons, direct stenting etc.) are inadequate. We report a case of a male patient, who previously underwent PCI of the right coronary artery (RCA) and was free of chest pain for several weeks, but his clinical symptoms have developed again. Angiography showed a “de novo”, highly calcified left anterior descending (LAD) lesion that, after high-pressure balloon inflation, failed to dilate, thus the intervention was suspended. RA was scheduled for the patient within one month. As a complication of the previous LAD dilatation attempt, a chronic dissection of the target lesion occurred. Problems arose during the direct wiring attempt of the main vessel and the true lumen was only found via plaque modification, after accessing a small septal branch. Accessing the true lumen was only possible by using a conventional cross-wire. This was exchanged to a RA wire, with the help of an over-the-wire (OTW) balloon catheter. RA and debulking of the target lesion was performed. An everolimus-eluting stent (BioMatrix, Biosensors Europe, Morges, Switzerland) was implanted, with excellent results. The patient is free of clinical symptoms since the intervention, which took place 14 months ago.

Predictive value of C-reactive protein after drug-eluting stent implantation

During the last few decades, with the evolution of techniques and materials and the increasing experience of operators, percutaneous coronary interventions (PCI) have become an equally efficient alternative to coronary artery bypass grafts for the treatment of most coronary stenoses. Bare-metal stent implantation represented a major step forward, compared with plain old balloon angioplasty (POBA), by improving the immediate angiographic success. However, the incidence of in-stent restenosis (ISR) remained unacceptably high. Development of the drug-eluting stent (DES) significantly improved the outcome of PCI by dramatically abating the rate of ISR and reducing the incidence of target lesion revascularization. However, ISR has not been eliminated and the persistence of metal vessel scaffolding also raises concern regarding the occurrence of late or very late stent thrombosis. POBA and stent implantation have been shown to induce a local and systemic inflammatory response, whose magnitude is associated with worse clinical outcome, and they increase the risk of ISR. C-reactive protein, a marker of systemic inflammation, has been demonstrated to predict clinical and angiographic outcome after POBA or bare-metal stent implantation. However, conflicting data regarding the prognostic value of C-reactive protein following DES implantation are available. In this paper, we review the literature regarding the clinical and pathophysiological association between inflammation and prognosis after DES implantation and suggest some possible therapeutic approaches to reduce inflammatory burden with the aim to improve clinical and angiographic outcome after PCI.

Impact of analyzing less image frames per segment for radiofrequency-based volumetric intravascular ultrasound measurements in mild-to-moderate coronary atherosclerosis

Volumetric radiofrequency-based intravascular ultrasound (RF–IVUS) data of coronary segments are increasingly used as endpoints in serial trials of novel anti-atherosclerotic therapies. In a relatively time-consuming process, vessel and lumen contours are defined; these contours are first automatically detected, then visually checked, and finally (in most cases) manually edited to generate reliable volumetric data of vessel geometry and plaque composition. Reduction in number of cross-sectional images for volumetric analysis could save analysis time but may also increase measurement variability of volumetric data. To assess whether a 50% reduction in number of frames per segment (every second frame) alters the reproducibility of volumetric measurements, we performed repeated RF–IVUS analyses of 15 coronary segments with mild-to-moderate atherosclerosis (20.2 ± 0.2 mm-long segments with 46 ± 13% plaque burden). Volumes were calculated based on a total of 731 image frames. Reducing the number of cross-sectional image frames for volumetric measurements saved analysis time (38 ± 9 vs. 68 ± 17 min/segment; P < 0.0001) and resulted for only a few parameters in (borderline) significant but mild differences versus measurements based on all frames (fibrous volume, P < 0.05; necrotic-core volume, P = 0.07). Compared to the intra-observer variability, there was a mild increase in measurement variability for most geometrical and compositional volumetric RF–IVUS parameters. In RF–IVUS studies of mild-to-moderate coronary disease, analyzing less image frames saved analysis time, left most volumetric parameters greatly unaffected, and resulted in a no more than mild increase in measurement variability of volumetric data.

Behçet's Disease: an Insight from a Cardiologist's Point of View

Behçet's disease (BD) is an enigmatic inflammatory disorder, with vasculitis (perivasculitis) underlying pathophysiology of its multisystemic affections. Venous pathology and thrombotic complications are hallmarks of BD. However, it has been increasingly recognized that cardiac involvement and arterial complications (aneurysms, pseudoaneurysms, rupture and thrombosis) are important part of the course of BD. Pericarditis, myocardial (diastolic and/or systolic dysfunction), valvular and coronary (thrombosis, aneurysms, rupture) involvement, intracardiac thrombi (predominantly right-sided) are, probably, the most frequent cardiac manifestations. Treatment of cardiovascular involvement in BD is largely empirical and aimed at suppression of vasculitis. The most challenging seems to be the treatment of arterial aneurysms and thromboses due to the associated risk of bleedings. Cardiologists should always bear in mind potential threats of (a)symptomatic cardiovascular involvement in BD.

Behçet’s Disease: an Insight from a Cardiologist’s Point of View

Behçet's disease (BD) is an enigmatic inflammatory disorder, with vasculitis (perivasculitis) underlying pathophysiology of its multisystemic affections. Venous pathology and thrombotic complications are hallmarks of BD. However, it has been increasingly recognized that cardiac involvement and arterial complications (aneurysms, pseudoaneurysms, rupture and thrombosis) are important part of the course of BD. Pericarditis, myocardial (diastolic and/or systolic dysfunction), valvular and coronary (thrombosis, aneurysms, rupture) involvement, intracardiac thrombi (predominantly right-sided) are, probably, the most frequent cardiac manifestations. Treatment of cardiovascular involvement in BD is largely empirical and aimed at suppression of vasculitis. The most challenging seems to be the treatment of arterial aneurysms and thromboses due to the associated risk of bleedings. Cardiologists should always bear in mind potential threats of (a)symptomatic cardiovascular involvement in BD.

Low-molecular-weight polyethylene glycol improves survival in experimental sepsis

OBJECTIVE

For several chronic inflammatory disease states, therapy is enhanced by improving the pharmacokinetic properties of anti-inflammatory drugs through conjugation with polyethylene glycol. We hypothesized that part of the beneficial action of PEGylated drugs may be derived from the anti-inflammatory properties of polyethylene glycol (PEG) itself.

DESIGN

Randomized, double-blinded, controlled ex vivo and in vivo laboratory studies.

SETTING

University research laboratories.

SUBJECTS

Human neutrophils and mononuclear cells, macrophage cell line, and adult rats and mice.

INTERVENTIONS

The effect of PEG (either low-molecular-weight [200-400] or high-molecular-weight [>4000]) was assessed on survival after systemic inflammation induced by lipopolysaccharide or zymosan. The effects of PEG on zymosan, lipopolysaccharide, or streptolysin-induced inflammatory and bioenergetic responses of immune cells were also assessed.

MEASUREMENTS AND MAIN RESULTS

Low-molecular-weight PEG reduced inflammatory cytokine expression, pyrexia, and mortality by >50% in both lipopolysaccharide and zymosan models of sepsis. Low-molecular-weight PEG reduced cytokine expression both in vivo and in vitro, and attenuated activation of human neutrophils in response to lipopolysaccharide or zymosan. By contrast, high-molecular-weight PEG conferred less significant survival effects after lipopolysaccharide and zymosan, and it did not exhibit such profound anti-inflammatory effects. Low-molecular-weight PEG attenuated lipopolysaccharide-induced activation of pro-apoptotic pathways (lysophosphatidic acid receptor and caspase-domain signaling) in the livers of endotoxemic rats. Streptolysin-induced necrosis of human neutrophils was reduced by low-molecular-weight PEG, indicating a mechanism that involves coating and/or stabilizing the cellular membrane. Low-molecular-weight PEG preserved human neutrophil responses to septic serum and bioenergetic function in macrophages and neutrophils.

CONCLUSION

PEG is a commonly used, safe, nonimmunogenic molecule possessing hitherto unappreciated anti-inflammatory properties. Low-molecular-weight PEG may potentially play a role in the therapy of systemic inflammation and sepsis.

Stromal cell-derived factor-1alpha-directed chemoattraction of transiently CXCR4-overexpressing bone marrow stromal cells into functionalized three-dimensional biomimetic scaffolds

Three-dimensional (3D) bone substitute material should not only serve as scaffold in large bone defects but also attract mesenchymal stem cells, a subset of bone marrow stromal cells (BMSCs) that are able to form new bone tissue. An additional crucial step is to attract BMSCs from the surface into deeper structures of 3D porous bone substitute scaffolds. Here we show that transient overexpression of CXCR4 in human BMSCs induced by mRNA transfection enhances stromal cell-derived factor-1alpha (SDF-1alpha)-directed chemotactic capacity to invade internal compartments of porous 3D bone substitute scaffolds in vitro and in vivo. In vitro native BMCSs invaded up to 500 mum into SDF-1alpha-releasing 3D scaffolds, whereas CXCR4-overexpressing BMSCs invaded up to 800 mum within 5 days. In addition, 60% downregulation of endogenous SDF-1 transcription in BMSCs by endoribonuclease-prepared siRNA before CXCR4 mRNA transfection enhanced SDF-1alpha-directed migration of human BMSCs by 50%. Implantation of SDF-1alpha-releasing scaffolds seeded with transiently CXCR4-overexpressing BMSCs resulted in an increase of invasion into internal compartments of the scaffolds in a mouse model. In vivo native BMCS invaded up to 250 mum into SDF-1alpha-releasing 3D scaffolds, whereas CXCR4-overexpressing BMSC invaded up to 500 mum within 5 days. Thus, the SDF-1alpha/CXCR4 chemoattraction system can be used to efficiently recruit BMSCs into SDF-1alpha-releasing 3D scaffolds in vitro and in vivo.

Comparison of long-term outcomes following sirolimus-eluting stent vs paclitaxel-eluting stent implantation in patients with long calcified coronary lesions

BACKGROUND

Although previously reported studies on coronary calcification mainly focused on its presence or absence in discrete focal target lesions, calcified coronary lesions (CCL) angiographically present as diffuse long lesions in some patients. The aim of our study was to evaluate the long-term efficacy of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) on long CCL.

METHODS

A total of 122 patients with 134 lesions (77 patients with 88 lesions for SES and 45 patients with 46 lesions for PES) were enrolled from 3 centers. Long CCL was defined visually as a culprit lesion with type B or C that was mainly due to coronary calcification with > 20 mm in total length by coronary angiography. Clinical follow-up was performed at 1 year and angiographic follow-up at 6 to 9 months after procedure. Major adverse coronary events (MACE) were defined as all-cause death, myocardial infarction (MI), and repeat target-lesion revascularization (TLR).

RESULTS

There were no statistically significant differences in baseline, procedural, or angiographic characteristics and in 1-year rates of all-cause death, MI, and TLR between the 2 groups (all P = NS [not significant]). Likewise, the cumulative incidence of MACE at 1 year was similar between the 2 groups (7.8% of patients in the SES group vs 4.4% of patients in the PES group, respectively, P = NS). In patients who underwent follow-up angiography, the angiographic binary restenosis rate was 6.2% in the SES group vs 12.1% in the PES group, respectively (P = NS).

CONCLUSION

In patients with long CCL, both SES and PES were comparably effective in either angiographic or clinical long-term outcomes.

Overlap of registered nurse and physician practice: implications for U.S. health care reform

This review offers an analysis of practice overlap between physicians and registered nurses (RNs) who are not advanced practice nurses. Additionally, it spotlights opportunities for expanding traditional professional boundaries to establish novel care delivery models. The examples of RN role expansion offer a beginning for discussion regarding how the health professionals' knowledge and skills can be best used in designing an effective and efficient health care system. Although limited data exist on cost effectiveness and workload implications of the novel care delivery models, policy makers can use the findings of this review to begin to inform U.S. health care reform.

Multiple MGuard stent implantation to treat massive right coronary artery dissection during primary coronary angioplasty

Here we report a case of a 79-year-old woman with inferior myocardial infarction, transferred to our cath lab to perform a primary percutaneous coronary intervention (PPCI). During the procedure, a massive dissection complicated the thrombotic lesion of the right coronary artery (RCA). In this case, we decided to use the MGuard stent to treat both the large dissection and the thrombotic lesion. MGuard stent is a combination of a coronary stent merged with an embolic protection device. After multiple MGuard stent implantation we obtained a complete resolution of the coronary dissection obtaining a patent RCA with normal antegrade flow.

Current Strategies in Cardiovascular Biomaterial Functionalization

Prevention of the coagulation cascade and platelet activation is the foremost demand for biomaterials in contact with blood. In this review we describe the underlying mechanisms of these processes and offer the current state of antithrombotic strategies. We give an overview of methods to prevent protein and platelet adhesion, as well as techniques to immobilize biochemically active molecules on biomaterial surfaces. Finally, recent strategies in biofunctionalization by endothelial cell seeding as well as their possible clinical applications are discussed.

Comparison of bone marrow stromal cell behaviors on poly(caprolactone) with or without surface modification: studies on cell adhesion, survival and proliferation

Poly(caprolactone) (PCL) is a promising biodegradable polymer for tissue engineering. However, intrinsically poor cell-adhesive properties of PCL may limit its application. In this study, the PCL film surface was modified with RGDC peptide by a chemical immobilization procedure. Furthermore, bone marrow stromal cell (BMSC) behaviors including attachment, spreading, focal adhesion formation, focal adhesion kinase (FAK) activation, apoptosis and proliferation when cultured on the modified PCL films were investigated. Our results demonstrated that PCL with RGD modification promoted initial BMSC attachment, spreading and focal adhesion formation. At a later time point (12 h), BMSC attachment on both RGD peptide-modified PCL and PCL-NH(2) films significantly increased compared to untreated PCL films. Importantly, FAK phosphorylation was significantly increased only on the films with RGD-modified films, not on the PCL-NH(2) films, demonstrating that PCL with RGD modification had an advantage in initiating the specific integrin-mediated signal transduction and might play an important role in the subsequent retardation in cell death and enhancement in cell proliferation. The present results provide more evidence that functionalizing PCL with RGD peptides may be a feasible way to improve the interaction between BMSC and PCL substrate, which is important in tissue engineering.

Evaluation of peripheral atherosclerosis: a comparative analysis of angiography and intravascular ultrasound imaging

OBJECTIVE

Angiography remains a critical component for diagnostic imaging and therapeutic intervention in peripheral arterial disease (PAD). The goal of this study was to compare angiography with corresponding intravascular ultrasound (IVUS) imaging of the same vessels in patients with PAD.

METHODS

From 2004 to 2008, 93 patients undergoing angiography for PAD were recruited in a prospective observational analysis. At the time of angiography, diseased lower extremities were interrogated using a 10-cm IVUS pullback with registration points. IVUS data were analyzed with radiofrequency techniques for vessel and lumen diameter, plaque volume, plaque composition, and cross-sectional area. Similarly, three vascular surgeons blinded to the IVUS data graded corresponding angiographic images according to vessel diameter, degree of stenosis, degree of calcification, and extent of eccentricity. Statistical analyses of matched IVUS images and angiograms were performed.

RESULTS

The distribution of demographic and risk variables were typical for PAD: 54% male, 96% hypertension, 78% hyperlipidemia, 44% diabetic, 87% tobacco history, 65% coronary artery disease, and 10% end-stage renal disease. Symptoms precipitating the angiographic evaluation included claudication (53%), rest pain (18%), and tissue loss (29%). Angiographic and IVUS interpretation were similar for luminal diameters, but external vessel diameter was greater by IVUS imaging (7.0 +/- 0.7 vs 5.2 +/- 0.8 mm, P < .05). The two-dimensional diameter method resulted in a significant correlation for stenosis determination (r = 0.84); however, IVUS determination of vessel area stenosis was greater by 10% (95% confidence interval, 0.3%-21%, P < .05). IVUS imaging indicated that a higher proportion of plaques were concentric. Grading of calcification was moderate to severe in 40% by angiography but in only 7% by IVUS (P < .05).

CONCLUSIONS

In the evaluation of PAD, angiography and IVUS imaging provide similar luminal diameters and diameter-reducing stenosis measurements. Determination of overall vessel diameter and interpretation of plaque morphology by angiography are discordant from IVUS-derived data.

Emerging drugs for acute myocardial infarction

IMPORTANCE OF THE FIELD

The present review is aimed at going over the pharmacological profile (and the clinical impact) of the emerging drugs involved in the management of patients with ST-elevation myocardial infarction (STEMI) in order to provide the cardiologists who deal with these patients in the early phase with the most recent evidence on this topic.

AREAS COVERED IN THIS REVIEW

Anticoagulant and antiplatelet drugs are the main cornerstones of therapy in the treatment of STEMI patients undergoing primary percutaneous coronary intervention (PCI). The main issues that clinicians have to deal with are represented by balancing thrombotic and bleeding risks. In tailoring therapy, variables such as age, sex and previous disease should be taken into account, as well as ongoing complications (such as acute renal failure) that could affect hemostasis. Despite the well-established clinical benefits of antiplatelet agents, questions remain, mainly surrounding potential for variable platelet response, which are strictly related to non-genetic (i.e., diet, drug-drug interaction, clinical factors such as obesity, diabetes mellitus, and inflammation) and genetic determinants.

WHAT THE READER WILL GAIN

In their daily practice, cardiologists cannot abstract from the knowledge and updating on the ongoing research fields as well as the newly developed drugs, which they should frame in the very patient in the attempt to the develop a personalized medical strategy. These include also the pharmacological option(s) in the treatment of the reperfusion injury, the metabolic aspects and the stem cell therapy. TAKE HOME MASSAGE: In our opinion, the goal of ongoing research on the pharmacological approach to STEMI patients is a personalized medical strategy that relies on critical clinicians who merge newly developed acquisitions on this topic and a more complete, systemic and critical approach to the patient.

Update on the everolimus-eluting coronary stent system: results and implications from the SPIRIT clinical trial program

Drug-eluting stents (DES) have had a major impact in interventional cardiology. Compared to bare metal stents, they significantly reduce restenosis and the need for target vessel revascularization. Four DES are available in the US, the first-generation sirolimus-eluting (Cypher^®) and paclitaxel-eluting (Taxus^®) stents and later approved second-generation everolimus-eluting (Xience V^®) and zotarolimus-eluting (Endeavor^®) stents. The Xience V stent was approved on the basis of clinical efficacy and safety data from 3 studies in the SPIRIT clinical trial program. Within this trial series, the Xience V was superior to its bare metal stent counterpart, the Vision® stent, and noninferior to the paclitaxel-eluting stent for target vessel failure at 9 months. This review provides a comprehensive assessment of the data derived from both the pre- and post-approval randomized controlled trials and registry studies of Xience V that comprise the SPIRIT clinical trial program including recently published mid-term outcomes. The implications of the results in terms of interventional practice will be discussed.

Distinct signaling pathways after higher or lower doses of radiation in three closely related human lymphoblast cell lines

PURPOSE

The tumor suppressor p53 plays an essential role in cellular responses to DNA damage caused by ionizing radiation; therefore, this study aims to further explore the role that p53 plays at different doses of radiation.

MATERIALS AND METHODS

The global cellular responses to higher-dose (10 Gy) and lower dose (iso-survival dose, i.e., the respective D0 levels) radiation were analyzed using microarrays in three human lymphoblast cell lines with different p53 status: TK6 (wild-type p53), NH32 (p53-null), and WTK1 (mutant p53). Total RNAs were extracted from cells harvested at 0, 1, 3, 6, 9, and 24 h after higher and lower dose radiation exposures. Template-based clustering, hierarchical clustering, and principle component analysis were applied to examine the transcriptional profiles.

RESULTS

Differential expression profiles between 10 Gy and iso-survival radiation in cells with different p53 status were observed. Moreover, distinct gene expression patterns were exhibited among these three cells after 10 Gy radiation treatment, but similar transcriptional responses were observed in TK6 and NH32 cells treated with iso-survival radiation.

CONCLUSIONS

After 10 Gy radiation exposure, the p53 signaling pathway played an important role in TK6, whereas the NFkB signaling pathway appeared to replace the role of p53 in WTK1. In contrast, after iso-survival radiation treatment, E2F4 seemed to play a dominant role independent of p53 status. This study dissected the impacts of p53, NFkB and E2F4 in response to higher or lower doses of gamma-irradiation.

A prospective evaluation of the safety and efficacy of the TAXUS Element paclitaxel-eluting coronary stent system for the treatment of de novo coronary artery lesions: design and statistical methods of the PERSEUS clinical program

Background

Paclitaxel-eluting stents decrease angiographic and clinical restenosis following percutaneous coronary intervention compared to bare metal stents. TAXUS Element is a third-generation paclitaxel-eluting stent which incorporates a novel, thinner-strut, platinum-enriched metal alloy platform. The stent is intended to have enhanced radiopacity and improved deliverability compared to other paclitaxel-eluting stents. The safety and efficacy of the TAXUS Element stent are being evaluated in the pivotal PERSEUS clinical trials.

Methods/Design

The PERSEUS trials include two parallel studies of the TAXUS Element stent in single, de novo coronary atherosclerotic lesions. The PERSEUS Workhorse study is a prospective, randomized (3:1), single-blind, non-inferiority trial in subjects with lesion length ≤28 mm and vessel diameter ≥2.75 mm to ≤4.0 mm which compares TAXUS Element to the TAXUS Express² paclitaxel-eluting stent system. The Workhorse study employs a novel Bayesian statistical approach that uses prior information to limit the number of study subjects exposed to the investigational device and thus provide a safer and more efficient analysis of the TAXUS Element stent. PERSEUS Small Vessel is a prospective, single-arm, superiority trial in subjects with lesion length ≤20 mm and vessel diameter ≥2.25 mm to <2.75 mm that compares TAXUS Element with a matched historical bare metal Express stent control.

Discussion

The TAXUS PERSEUS clinical trial program uses a novel statistical approach to evaluate whether design and metal alloy iterations in the TAXUS Element stent platform provide comparable safety and improved procedural performance compared to the previous generation Express stent. PERSEUS trial enrollment is complete and primary endpoint data are expected in 2010. PERSEUS Workhorse and Small Vessel are registered at http://www.clinicaltrials.gov, identification numbers NCT00484315 and NCT00489541.

Epidemiology and natural history of atherosclerotic renovascular disease

Atheromatous renovascular disease (ARVD) is increasingly suspected and diagnosed, and it commonly presents to several different clinical specialties. In this review, the epidemiology, risk factors, comorbid disease associations, natural history, and prognosis of ARVD is described. Atheromatous renovascular disease is strongly associated with macrovascular pathology in other important vascular beds, especially the coronary, aortoiliac and iliofemoral circulations, and also with structural and functional heart disease. These clinicopathologic relationships contribute to the high morbidity and mortality associated with the condition. Understanding of the natural history of renal artery stenosis may enable intensified treatment strategies to reduce associated risk and improve patient prognosis.