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Background: Geriatric patients with multivessel coronary artery disease (CAD) are a challenging group to treat; these cases elicit discussion within heart teams regarding the actual benefit of undertaking major surgery on these patients and often lead to abandon the surgical option. Percutaneous procedures represent an important option, but coronary anatomy may be unfavorable. Off-pump coronary artery bypass (OPCAB) provides good quality graft on left anterior descending (LAD) without exposing the patient to cardiopulmonary bypass, and might be the ideal choice in patients with multiple comorbidities, not eligible to percutaneous or on-pump procedures. The objective of this study was to compare survival during a mid-term follow-up in high-risk patients with no percutaneous alternative, either treated with OPCAB or discharged in medical therapy., Methods: We retrospectively evaluated from June 2008 to June 2013, 83 high-risk patients with multivessel CAD were included: 42 were treated with incomplete off-pump revascularization using left internal mammary artery (LIMA) on LAD; 41 were discharged in optimal medical therapy (OMT), having refused surgery. Follow-up ended in March 2015, with a telephonic interview. Primary endpoint was survival from all-cause mortality; secondary endpoints were survival from cardiac-related mortality and freedom from non-fatal major adverse cardiac events (MACEs)., Results: During follow up, 11 deaths in OPCAB group and 27 deaths in OMT group occurred. Death was due to cardiac factors in 6 and 15 patients, respectively. MACEs were observed in 6 patients in OPCAB group and in 4 patients in OMT group. With regards to survival from all-cause mortality, patients who underwent OPCAB survived more than those discharged in OMT (Log Rank < 0.001), and OMT group carries a propensity score-adjusted hazard ratio of 3.862 (P < 0.001). With regards to survival from cardiac-related events, patients who underwent OPCAB survived more than those discharged in OMT (Log Rank = 0.002), and OMT group carries a propensity score-adjusted hazard ratio of 3.663 (P = 0.010). There is no statistically significant difference concerning freedom from MACEs (Log Rank = 0.273)., Conclusions: For high-risk patients with multivessel CAD, not eligible to on-pump complete revascularization surgery or percutaneous procedures, incomplete revascularization with OPCAB LIMA-on-LAD offers benefits in survival when compared to OMT alone.

Background: Supravalvular pulmonary stenosis (SPS) remains a worrisome complication in the long term of simple transposition of the great arteries. Issues of scar formation and inability to grow are considered at the base of this phenomenon. We pioneered the use of a tissue engineering approach to guide the maturation and the growth of pulmonary autograft in the Ross procedure with encouraging results. We therefore sought to investigate the use of a similar approach in the reconstruction of neopulmonary trunk (NPT) with the aim to recreate a vascular conduit that retains the structural architecture and the same biological potential of native pulmonary artery and prevents long-term SPS., Methods: A model of NPT reconstruction in growing lambs was used. NPT was constructed with autologous pericardium and reinforced with a four-layered knitted polydioxanone mesh (PDS n=10) or left unreinforced (control n=10). Animals were left growing for 6 months and angiographic and transesophageal echocardiographic measurements were performed at day 1 and at the end of the study together with histological analysis., Results: Control group developed SPS while PDS reinforcement allowed a progressive increase in diameter with an optimal size to match the pulmonary artery of healthy growing controls. Histological analysis showed in the control group disruption of endothelial lining with fibrosis, while demonstrated in the PDS group a trilaminar vessel-like structure., Conclusions: The bioresorbable reinforcement induced the formation over time of a neopulmonary conduit able to both face the hemodynamic load of the pulmonary system and guarantee a harmonious increase in size during the somatic growth., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Aims: Statin pretreatment in patients undergoing cardiac surgery is understood to prevent postoperative atrial fibrillation (AF). However, this is based on observational and limited randomized trial evidence, resulting in uncertainty about any genuine anti-arrhythmic benefits of these agents in this setting. We therefore aimed to quantify precisely the association between statin pretreatment and postoperative AF among patients undergoing cardiac surgery., Methods and Results: A detailed search of MEDLINE and PubMed databases (1st January 1996 to 31st July 2012) was conducted, followed by a review of the reference lists of published studies and correspondence with trial investigators to obtain individual-participant data for meta-analysis. Evidence was combined across prospective, randomized clinical trials that compared the risk of postoperative AF among individuals randomized to statin pretreatment or placebo/control medication before elective cardiac surgery. Postoperative AF was defined as episodes of AF lasting ≥5 min. Overall, 1105 participants from 11 trials were included; of them, 552 received statin therapy preoperatively. Postoperative AF occurred in 19% of these participants when compared with 36% of those not treated with statins (odds ratio 0.41, 95% confidence interval 0.31-0.54, P < 0.00001, using a random-effects model). Atrial fibrillation prevention by statin pretreatment was consistent across different subgroups., Conclusion: Short-term statin pretreatment may reduce the risk of postoperative AF among patients undergoing cardiac surgery., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Context: Advanced Glycation End-Products (AGEs) are signaling proteins associated to several vascular and neurological complications in diabetic and non-diabetic patients. AGEs proved to be a marker of negative outcome in both diabetes management and surgical procedures in these patients. The reported role of AGEs prompted the development of pharmacological inhibitors of their effects, giving rise to a number of both preclinical and clinical studies. Clinical trials with anti-AGEs drugs have been gradually developed and this review aimed to summarize most relevant reports., Evidence Acquisition: Evidence acquisition process was performed using PubMed and ClinicalTrials.gov with manually checked articles., Results: Pharmacological approaches in humans include aminoguanidine, pyridoxamine, benfotiamine, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, statin, ALT-711 (alagebrium) and thiazolidinediones. The most recent promising anti-AGEs agents are statins, alagebrium and thiazolidinediones. The role of AGEs in disease and new compounds interfering with their effects are currently under investigation in preclinical settings and these newer anti-AGEs drugs would undergo clinical evaluation in the next years. Compounds with anti-AGEs activity but still not available for clinical scenarios are ALT-946, OPB-9195, tenilsetam, LR-90, TM2002, sRAGE and PEDF., Conclusions: Despite most studies confirm the efficacy of these pharmacological approaches, other reports produced conflicting evidences; in almost any case, these drugs were well tolerated. At present, AGEs measurement has still not taken a precise role in clinical practice, but its relevance as a marker of disease has been widely shown; therefore, it is important for clinicians to understand the value of new cardiovascular risk factors. Findings from the current and future clinical trials may help in determining the role of AGEs and the benefits of anti-AGEs treatment in cardiovascular disease.

Mitral valve prolapse occurs in 33.6% of patients undergoing surgery for ischemic mitral regurgitation (IMR). In the context of IMR, reparative strategy cannot disregard the underlying mechanism of pathogenesis and the progressive geometric alteration affecting left ventricle and papillary muscles. We present a case of extended mitral prolapse of the posteromedial commissure and A3 concomitant to chordal injury after inferior myocardial infarction. We propose a combined sequential approach including papillary muscle approximation and a mitral chordae system replacement.

Objectives: To circumvent the issue of pulmonary autograft (PA) dilation after the Ross procedure, surgical reinforcement strategies have been suggested in clinical or anecdotal series. However, no preclinical large-animal model of the Ross procedure is available, which is needed to enable full comprehension of the pathologic mechanisms and the effectiveness of reinforcement techniques during growth. Our aim was to develop a large-animal model of the Ross operation, to reproduce the clinical scenario in which this procedure might be applied, and allow for development and testing of various devices and techniques to improve PA performance. In addition, we aimed to test the effectiveness of a bioresorbable mesh for PA reinforcement., Methods: An experimental model of transposition of the pulmonary trunk as an autograft in the aortic position has been developed and performed under cardiopulmonary bypass in 20 growing lambs, aged 3 months. The experimental design included: a control group that underwent PA transposition; a group in which the PA was reinforced with an external, synthetic, nonresorbable, polypropylene grid; and a group that received various combinations of resorbable meshes. Animals were followed up during growth for 6 months by angiography and echocardiography and eventually killed for pathologic analysis., Results: All animals survived the procedure with no complications. The model was easy and reproducible. Resorbable meshes prevented PA dilation and preserved its progressive growth process, aiding histologic remodelling., Conclusions: We developed an easy and reproducible model of the Ross procedure, allowing for a reliable simulation of the clinical scenario. Resorbable PA reinforcement may represent an interesting option in this context., (Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Diabetes is a major risk factor for cardiovascular disease, and recent advances in research indicate that a detailed understanding of the pathophysiology of its effects is mandatory to reduce diabetes-related mortality and morbidity. Advanced Glycation End Products (AGEs) play a central role in the genesis and progression of complications of both type 1 and type 2 diabetes mellitus, and have been found to be important even in non-diabetic patients as a marker of cardiovascular disease. AGEs have a profound impact on patient's prognosis regardless of the glycemic control, and therefore pharmacologic approaches against AGEs accumulation have been proposed over the years to treat cardiovascular diseases, parallel to a more detailed understanding of AGEs pathophysiology. Compounds with anti-AGEs effects are currently under investigation in both pre-clinical and clinical scenarios, and many of the drugs previously used to treat specific diseases have been found to have AGE-inhibitory effects. Some products are still in "bench evaluation", whereas others have been already investigated in clinical trials with conflicting evidences. This review aims at summarizing the mechanisms of AGEs formation and accumulation, and the most relevant issues in pre-clinical and clinical experiences in anti-AGEs treatment in cardiovascular research.

Cardiovascular aging is a physiological process gradually leading to structural degeneration and functional loss of all the cardiac and vascular components. Conduction system is also deeply influenced by the aging process with relevant reflexes in the clinical side. Age-related arrhythmias carry significant morbidity and mortality and represent a clinical and economical burden. An important and unjustly unrecognized actor in the pathophysiology of aging is represented by the extracellular matrix (ECM) that not only structurally supports the heart determining its mechanical and functional properties, but also sends a biological signaling regulating cellular function and maintaining tissue homeostasis. At the biophysical level, cardiac ECM exhibits a peculiar degree of anisotropy, which is among the main determinants of the conductive properties of the specialized electrical conduction system. Age-associated alterations of cardiac ECM are therefore able to profoundly affect the function of the conduction system with striking impact on the patient clinical conditions. This review will focus on the ECM changes that occur during aging in the heart conduction system and on their translation to the clinical scenario. Potential diagnostic and therapeutical perspectives arising from the knowledge on ECM age-associated alterations are further discussed.

The long-term outcomes of undersizing annuloplasty for the treatment of ischemic mitral regurgitation (IMR) is affected by the progressive dilation of the annulus, which carries increased risk for ring disinsertion. Reasons underlying this phenomenon might be found in the excess of physical stress on the annuloplasty sutures during the ventricular remodeling process. We report a technique based on the placement of a double row of overlapping sutures aiming at reducing the potential for ring disinsertion. Eleven patients with IMR undergoing mitral valve repair associated with coronary bypass grafting were treated with this technique and echocardiographically followed up at 6 and 12 months. The overall annular dimension decreased significantly with a significant reduction of the tenting area and no recurrence of mitral regurgitation at 1 year. A double row of overlapping sutures allowed firm attachment of the prosthetic ring while downsizing the annulus in IMR, limiting the consequences of changes in subannular ventricular geometry. This technique might therefore be considered a useful aid during mitral valve repair.

Objective: This study examines the outcomes of the cryopreserved mitral homograft in 110 patients prospectively followed with clinical, echocardiographic and structural valve deterioration (SVD) assessments., Methods: The etiology of mitral disease was: rheumatic disease (n = 70), endocarditis (n = 33), and others (n = 7). There were 31 partial homografts and 79 total homografts. Mitro-aortic homograft valve replacement was performed in 29 cases., Results: Mean follow-up was 9.8 ± 6.3 years (up to 19.2 years). There were seven early (<3 months) and 13 late deaths. There have been nine early (<3 months) and 24 late reoperations. Postoperatively, nine patients had endocarditis and six had an ischemic event. As compared to baseline, follow-up echocardiography showed progression of MR grade (from 0.4 to 1.3 p < 0.001) with stenosis (elevated gradient: from 3.9 to 7.0 mmHg p < 0.001 and decreased valve area: from 2.3 to 1.7 cm(2) p < 0.001). The proportion of freedom from SVD was 90%, 76%, and 65% at five years, 10 years, and 15 years, respectively. SVD was more frequent in pregnant patients (p = 0.016 vs. no pregnancy) and in patients with a ring smaller than 30 mm. Stenosis related to SVD was more pronounced for age <40 years and ring size 30 mm. Mitral-aortic homograft valve replacement was the preferred choice in complex infective endocarditis. Pathological analysis of the explanted homografts almost invariably showed dense fibrosis with calcification and no cellularity., Conclusion: Mitral homografts have early echocardiographic results similar to those of valve repair. SVD produced mixed stenosis with insufficiency and its incidence was comparable to that of bioprosthetic SVD. An improvement in the preservation mode of valvular homografts is warranted., (© 2014 Wiley Periodicals, Inc.)

Background: use of a prosthetic ring is an integral part of any mitral valve repair and can influence the long-term stability of the results. We evaluated the long-term results of the AnnuloFlex ring implanted as an open flexible band in patients affected by degenerative mitral disease., Methods: between 2001 and 2010, 82 patients (52 women, 30 men) with a mean age of 62 years, underwent repair of a prolapsing mitral valve with an AnnuloFlex band. One patient was reoperated on for a technical error and received a mechanical prosthesis, 3 were missing at follow-up, and the other 78 were prospectively followed up with clinical interviews and transthoracic echocardiography., Results: the mean follow-up was 7.0 ± 1.8 years. Six patients died; 2 deaths were considered valve-related. The overall survival estimate at 10 years was 88.6% (95% confidence interval: 76.1%-94.8%). Freedom from endocarditis was 97.1% (95% confidence interval: 89.1%-98.5%). Freedom from thrombosis or hemorrhage was 93.7% (95% confidence interval: 81.6%-97.9%). Freedom from new or increased regurgitation was 93.1% (95% confidence interval: 87.3%-97.3%). The cumulative freedom from any valve-related event was 78.6% (95% confidence interval: 69.7%-97.1%). A single case of systolic anterior motion occurred before hospital discharge., Conclusion: the long-term results of the AnnuloFlex band are excellent and stable., (© The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Anomalous origin of the left coronary artery originating from the opposite sinus of Valsalva is a coronary anomaly with a consistently low prevalence rate. Different patterns have been described for this type of anomaly with respect to the position and course of the coronary arteries. The interarterial type can be considered a malignant variant, as it is characterized by a left main coronary artery that is positioned between the aortic root and the pulmonary artery root, and it frequently presents with syncope or aborted sudden cardiac death. Other symptoms or clinical presentations include the presence or development of angina, acute myocardial infarction and ventricular tachycardia. We present the case of a 49-year old man who presented with a new onset of chest pain; a coronary angiogram showed an anomalous left main coronary artery arising from the right Valsalva sinus, accompanied by a long and severe stenosis. It was found that multi-scan cardiac tomography is very useful in identifying the position of the coronary arteries when coronary anomalies occur., (© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

The majority of approaches currently described and practiced in mitral repair surgery result in the vertical immobilization of the posterior leaflet, with the anterior leaflet striving to produce an adequate coaptation. Despite the satisfactory hemodynamic outcome and disappearance of mitral regurgitation, this non-physiological situation results in a redistribution of forces within the mitral apparatus with an increased stress on the leaflets. Biological evidences are pointing at the ability of the valvular interstitial cells to actively respond to biomechanical changes, switching their phenotype and producing different patterns of extracellular matrix proteins. This biological event translates to changes in the anatomical and mechanical properties of the leaflets, leading to an increased stiffening and a susceptibility to develop calcification. These concepts find a clinical reflex in reports on the long-term thickening and calcification of the leaflets after mitral repair, and in the leaflets remodeling phenomena described in chronically dilated ventricles. The importance of respecting the physiological movement and dynamics of the leaflets when performing a valvuloplasty is underlined, and a potential pharmacological modulation of the aforementioned biological processes to ameliorate long-term results of the repair is hypothesized.

The case is reported of a 38-year-old male patient with pulmonary homograft acute infective endocarditis and aortic root dilation that occurred 13 years after a Ross procedure for bicuspid aortic valve regurgitation. Aortic and pulmonary root replacements were performed, using a Freestyle stentless aortic root bioprosthesis in both cases, with excellent hemodynamics on postoperative echocardiography. In addition, preoperative systemic septic embolization had occurred despite an absence of left-sided endocarditis, presumably due to an intrapulmonary shunt. This case report demonstrates the feasibility of a double stentless bioprosthesis approach, and stresses the need to remain vigilant for septic embolization even in isolated right-sided endocarditis.

Background and Aim of the Study: Synthetic materials used for pulmonary autograft (PA) reinforcement in the Ross procedure fail to match the demand for structural growth, have only a limited longevity, and do not guarantee adequate vascular compliance in high-pressure load systems. The study aim was to develop a resorbable reinforcement of a PA, tailored to provide structural support and to guide the process of wall structure modification for the preservation of graft viability., Methods: An experimental model of translocation of the pulmonary trunk as an autograft in the aortic position was developed and performed under cardiopulmonary bypass in young lambs. The PA was left without reinforcement, reinforced with standard commercially available mesh, or reinforced with resorbable mesh of polyglactin and polydioxanone., Results: Based on vessel diameter measurements by transesophageal echography at day 0 and at six months postoperatively, only the PA with resorbable reinforcement showed a behavior similar to that of the normal aorta in a growing lamb. With the non-resorbable reinforcement, transmural migration of the mesh was observed, accompanied by a conspicuous inflammatory infiltrate and fibrosis., Conclusion: The resorbable mesh allowed for histological wall modification, characterized by the presence of highly organized smooth muscle cells and elastic lamellae in the media. The mechanical and histological features of this resorbable mesh-reinforced PA may be crucial to the clinical long-term success of the Ross procedure.

The first aortic valve homograft was implanted by Sir Donald Ross in 1962. Since then, over 25,000 aortic homografts have been implanted worldwide. Unfortunately, the current cryopreservation method promotes a degenerative process leading to progressive homograft fibrosis and calcification. Valve durability of fresh allografts appears to be superior to cryopreserved grafts. The main indications of aortic valve replacement with a homograft are endocarditis, rheumatic disease, bicuspid and dystrophic aortopathies. Our experience with 210 aortic homografts implanted over a 10-year period is reported. We describe the different implantation techniques with particular emphasis on the current technique of choice, namely homograft root replacement. Approximately one-fourth of all aortic homografts will experience structural valve deterioration at 12 years. Structural homograft valve deterioration translates predominately into valve insufficiency and less frequently into stenosis. Young recipient age it appears is the major determinant of reoperation. Predictors of early and late mortality are discussed.

Background: Advanced glycation endproducts (AGEs) and its receptors (RAGEs) are heterogeneous signaling proteins associated to diabetes and responsible of endothelial alterations leading to atherosclerosis progression and graft failure. The aim of this study was to investigate the role of statin in reducing AGEs related endothelial damage., Methods: Endothelial cell(EC) obtained from leftovers of saphenous vein grafts of non-diabetic patients were incubated with AGEs (2 and 20 μM) and subsequently treated with Simvastatin. Neutrophils (PNM) adherence, ROS production and RAGE and peroxisome proliferator-activated receptors-gamma (PPAR-γ) expression were analyzed. As clinical validation of the in vitro findings, ECs of diabetic patients in optimized glycaemic control administered with a 3 weeks Simvastatin regimen were similarly processed., Results: Simvastatin blunted the rise in PMN adhesion and ROS generation following stimulation of saphenous vein EC culture with AGEs in vitro. This effect was time dependent and was associated to an increase in PPAR-γ induction paralleled by a decrease in RAGEs expression. Parallely, data from diabetic patients administered with Simvastatin showed a similar significant reduction in PNM adhesion and ROS generation. Simvastatin treatment significantly decreased RAGEs expression in ECs from diabetic patients and determined a slight increase in PPAR-γ expression but the latter failed to reach statistical significance. Interference in the function of these two crucial pathways might be at the root of the statin antinflammatory and antithrombotic effect in the context of AGEs-associated damage., Conclusions: Despite the recently raised warning on the use of statins in the diabetic population, this study elucidates their cornerstone position in endothelial homeostasis of saphenous grafts in patients with controlled diabetes., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Diabetes mellitus (DM) remains the main predictor of restenosis rates and cardiovascular events following successful percutaneous coronary intervention (PCI) despite the use of drug-eluting stents (DES). HbA1c <6.0% is considered an index of optimized metabolic control in patients with DM, but several studies are downsizing its role in the clinical management of these patients. Increasing evidence points at the role of advanced glycation end products (AGEs) in restenosis pathogenesis independently on Hb1AC levels. Thus, we investigated the predictive value of preprocedural AGE levels for in-stent restenosis in a population of euglycaemic diabetic patients undergoing PCI with DES implantation. One hundred twenty-five consecutive patients with DM in optimized glycemic control admitted for stable angina pectoris and treated with elective DES implantation at a tertiary hospital were prospectively included. The primary end point of the ARMYDA-AGEs study was to compare rates of angiographic ISR at 6 months after the intervention according to pre-PCI levels of AGEs. Secondary end points were the correlations of AGE levels with occurrence of periprocedural myocardial damage, major adverse cardiac events, and in-stent late loss at 6-month control coronary angiography. AGE levels >17 μM was found to be an independent predictor of ISR at 6 months and stent lumen loss. AGEs failed to predict occurrence of secondary endpoints. In conclusion, elevated AGE levels predict occurrence of in-stent restenosis after DES implantation in patients with DM on optimized glycemic control and might represent a dosable marker of adverse outcome after PCI., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Electrostimulation represents a well-known trophic factor for different tissues. In vitro electrostimulation of non-stem and stem cells induces myogenic predifferentiation and may be a powerful tool to generate cells with the capacity to respond to local areas of injury. We evaluated the effects of in vivo electrostimulation on infarcted myocardium using a miniaturized multiparameter implantable stimulator in rats. Parameters of electrostimulation were organized to avoid a direct driving or pacing of native heart rhythm. Electrical stimuli were delivered for 14 days across the scar site. In situ electrostimulation used as a cell-free, cytokine-free stimulation system, improved myocardial function, and increased angiogenesis through endothelial progenitor cell migration and production of vascular endothelial growth factor (VEGF). In situ electrostimulation represents a novel means to stimulate repair of the heart and other organs, as well as to precondition tissues for treatment with cell-based therapies.

Background: Molecular mechanisms underlying abdominal aneurysm (AAA) formation and rupture are not well understood. Early detection and repair of AAA may reduce the high mortality rates associated with rupture. Serum proteomics allows the detection of alterations in the expression of proteins, guiding further studies on these target molecules as potential markers. Analysis of proteomic profile of asymptomatic patients with AAA allows the identification of reliable predictors or markers of disease presence or progression., Methods: A proteomics approach based on two-dimensional electrophoresis and mass spectrometry was used to compare serum proteomic profiles of patients with AAA who are candidates for surgical repair compared with healthy controls. We analyzed in parallel the proteomic profile of subjects with cardiac heart failure to discriminate these two pathologies, which show similar pattern of systemic inflammation process., Results: We identified in AAA subjects four serum proteins that show altered expression profile and that could be specifically linked to AAA pathology. We discuss the role of our identified proteins with their possible implications in disease outcome., Conclusions: This approach could provide an initial screening tool that may drive the basis for further research in the field of cardiovascular diseases. These results need to be validated in larger studies to find potential markers of AAA presence or progression to use in clinical settings., Summary: A proteomics approach was used to compare serum proteomic profiles of patients with abdominal aortic aneurysm who are candidates for surgical repair compared with healthy controls. Four serum proteins showed altered expression profile that could be correlated with the pathology. This approach could provide an initial screening tool that may drive the basis for further research in the field of cardiovascular diseases., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Nickel allergy can raise clinical problems in patients undergoing cardiac surgery who require sternal closure with stainless steel wire. We describe the case of a 51-year-old woman with severe nickel allergy who underwent aortic valve replacement with a nickel-free ON-X prosthesis and sternal closure by Fiberwire # 2 suture without complications. Considering its biocompatibility and its mechanical characteristics including optimal strength and knot resistance, this suture might be a viable alternative in patients in which the use of stainless steel wire is contraindicated., (© 2011 Wiley Periodicals, Inc.)

Sternal synthesis after median sternotomy, a conventional access practice in thoracic and cardiac surgery, is at the basis of severe complications, often impairing the clinical outcome of surgical interventions. In this work, we propose the use of an acellular biomaterial scaffold, to be interposed across the fracture rime during closure operations, directly exposing the biomaterial to bone marrow, in order to expedite healing process. A rabbit model of median sternotomy was performed and an electrospun scaffold composed of a hydroxyapatite-loaded absorbable biopolymer (poly-L: -lactide), shaped into a fibrillar structure, was used. CT follow-up confirmed a complete healing in the scaffold-treated group 1 week before the control. Histological evaluation demonstrated presence of newly formed bone trabeculae among scaffold fibers showing a higher degree of maturity with respect to the control untreated group. The proposed approach is able to both guide a more rapid healing and modulate inflammatory response across the wound site, resulting in improved healing and tissue remodeling with respect to conventional closure technique.

Cardiac regeneration requires a complex cascade of events. Stem cell therapy and tissue engineering are newly emerging tools with promising potential for recover or replace of damaged cardiac tissue. There are many factors, most of them still no clarified, that limit the effectiveness of these treatments and their translation to the clinic. Cells should graft, survive and functionally integrate to the target organ in order to have a chance to restore its function. As in original tissues, a complex and well defined set of signals, many of them coming from the extracellular matrix, is required for normal cell physiology. Biomaterials science gives us important tools to build this extracellular matrix. Functionalized 3D systems can provide the correct environment and act as a delivery system for genes or gene products, guiding the therapeutic cells to the functional phenotype.

Myocardial infarction and its consequences represent one of the most demanding challenges in cell therapy and regenerative medicine. Transfer of skeletal myoblasts into decompensated hearts has been performed through intramyocardial injection. However, the achievements of both cardiomyocyte differentiation and precise integration of the injected cells into the myocardial wall, in order to augment synchronized contractility and avoid potentially life-threatening alterations in the electrical conduction of the heart, still remain a major target to be pursued. Recently, granulocytes colony-stimulating factor (G-CSF) fuelled the interest of researchers for its direct effect on cardiomyocytes, inhibiting both apoptosis and remodelling in the failing heart and protecting from ventricular arrhythmias through the up-regulation of connexin 43 (Cx43). We propose a tissue engineering approach concerning the fabrication of an electrospun cardiac graft functionalized with G-CSF, in order to provide the correct signalling sequence to orientate myoblast differentiation and exert important systemic and local effects, positively modulating the infarction microenvironment. Poly-(L-lactide) electrospun scaffolds were seeded with C2C12 murine skeletal myoblast for 48 hrs. Biological assays demonstrated the induction of Cx43 expression along with morphostructural changes resulting in cell elongation and appearance of cellular junctions resembling the usual cardiomyocyte arrangement at the ultrastructural level. The possibility of fabricating extracellular matrix-mimicking scaffolds able to promote myoblast pre-commitment towards myocardiocyte lineage and mitigate the hazardous environment of the damaged myocardium represents an interesting strategy in cardiac tissue engineering., (© 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.)

Aims: Current limitations of tissue-engineered vascular grafts include timing for the scaffold preparation, cell type, cell differentiation and growth inside the construct, and thrombogenicity of the final device. To surmount these shortcomings, we developed a heparin-releasing poly-L-lactide (PLLA) scaffold using the electrospinning technique, to guide the differentiation of human mesenchymal stem cells towards the endothelial phenotype and to deliver a useful drug in the management of the postimplantation period., Materials & Methods: The heparin-releasing PLLA scaffold was produced by means of the electrospinning technique in a tubular shape. The scaffold was seeded with human mesenchymal stem cells and cultured for up to 1 week. Cell viability and cytotoxicity assays were performed, and cell differentiation was evaluated by immunofluorescence with confocal microscopy, cytofluorometry and western blotting. Heparin release was assayed by Azure A method and biological effectiveness of the drug was assessed by activated clotting time measurements., Results: The scaffold exhibited a morphology favorable to cell attachment. Heparin release showed an initial burst within the first 24 h, followed by a further sustained release profile. After 48 h of culturing, the construct demonstrated adequate engraftment and viability. Increased proliferation compared with the control scaffold in bare PLLA, suggested the induction of a favorable microenvironment. A shift towards CD31 positivity and modifications in cell morphology were observed in the heparin-releasing PLLA scaffold., Conclusion: By exploiting the biological effects of heparin, we developed an ad hoc differentiating device towards the endothelial phenotype for autologous stem cell seeding and, at the same time, we were able to facilitate and optimize the management of the construct once in clinical settings.

Stem cell therapy is a major field of research worldwide, with increasing clinical application, especially in cardiovascular pathology. However, the best stem cell source and type with optimal safety for functional engraftment remains unclear. An intermediate cardiac precommitted phenotype expressing some of the key proteins of a mature cardiomyocyte would permit better integration into the cardiac environment. The predifferentiated cells would receive signals from the environment, thus achieving gradual and complete differentiation. In cell transplantation, survival and engraftment within the environment of the ischemic myocardium represents a challenge for all types of cells, regardless of their state of differentiation. An alternative strategy is to embed cells in a 3-dimensional structure replicating the extracellular matrix, which is crucial for full tissue restoration and prevention of ventricular remodeling. The clinical translation of cell therapy requires avoidance of potentially harmful drugs and cytokines, and rapid off-the-shelf availability of cells. The combination of predifferentiated cells with a functionalized scaffold, locally releasing molecules tailored to promote in-situ completion of differentiation and improve homing, survival, and function, could be an exciting approach that might circumvent the potential undesired effects of growth factor administration and improve tissue restoration.

Electrospinning of biopolymeric scaffolds is a new and effective approach for creating replacement tissues to repair defects and/or damaged tissues with direct clinical application. However, many hurdles and technical concerns regarding biological issues, such as cell retention and the ability to grow, still need to be overcome to gain full access to the clinical arena. Interaction with the host human tissues, immunogenicity, pathogen transmission as well as production costs, technical expertise, and good manufacturing and laboratory practice requirements call for careful consideration when aiming at the production of a material that is available off-the-shelf, to be used immediately in operative settings. The issue of sterilization is one of the most important steps for the clinical application of these scaffolds. Nevertheless, relatively few studies have been performed to systematically investigate how sterilization treatments may affect the properties of electrospun polymers for tissue engineering. This paper presents the results of a comparative study of different sterilization techniques applied to an electrospun poly-L-lactide scaffold: soaking in absolute ethanol, dry oven and autoclave treatments, UV irradiation, and hydrogen peroxide gas plasma treatment. Morphological and chemical characterization was coupled with microbiological sterility assay to validate the examined sterilization techniques in terms of effectiveness and modifications to the scaffold. The results of this study reveal that UV irradiation and hydrogen peroxide gas plasma are the most effective sterilization techniques, as they ensure sterility of the electrospun scaffolds without affecting their chemical and morphological features.

Targeting wound repair, we developed an electrospun poly-L-lactide fibrous scaffold functionalized with G-CSF, a growth factor which is widely recognized as important in wound healing homeostasis. The scaffold was characterized in terms of morphology, mechanical properties and in vitro capacity to induce organization of co-cultures of murine fibroblasts and keratinocytes into a dermo-epidermal multilayered structure. Our findings are consistent with the promotion of a nonhostile environment, in which seeded cells could arrange themselves in an appropriate topographic distribution of elements at different levels of maturation up to a cornified epithelium on the top layer, resembling native skin.

Tissue engineering of vascular grafts still presents several shortcomings. Aiming to vascular regeneration, we developed a biomimetic multilayered scaffold with a middle pivotal collagen lamina between two functionalized layers of poly-L-lactide by means of electrospinning technique, with oriented drug-delivery capacity for the differentiation of human mesenchymal stem cells seeded therein. Applying appropriate cytokines, the inner layer is able to act as a drug delivery system in order to generate a pro-angiogenic and anti-thrombotic environment and the outer one is used to induce the media and adventitia generation. Our findings are consistent with an adequate cell engrafting and a double type of differentiation in each side of the scaffold, in particular cells exhibited morphostructural changes resulting in the achievement of an endothelial-like phenotype in cells populating the inner side of the scaffold and SMA positivity with cell elongation resembling muscular phenotype in the cells of the outer layer. The proposed "smart" vascular bio-prosthesis will recapitulate the structure and microenvironment of native cardiovascular tissues. It could surmount many hurdles to clinical use and would be relevant for therapeutic applications in a variety of medical fields.

Endothelial progenitor cells (EPCs) are a subtype of hematopoietic stem cells, which contribute to the repair of injured endothelium. Treatment with atorvastatin has been shown to increase EPC count in patients with coronary artery disease. Therefore, we investigated whether atorvastatin augments the number of EPCs after cardiopulmonary bypass (CPB) surgery. We conducted a randomized double-blind, placebo-controlled, 2-way crossover trial in 50 patients undergoing elective coronary surgery. Patients received either 3-week treatment with atorvastatin or placebo. EPCs were quantitated by flow cytometric phenotyping on blood samples. Levels of interleukin, IL-6 and IL-8; tumor necrosis factor alpha; SDF-1alpha; granulocyte colony-stimulating factor; and vascular endothelial growth factor were determined at recruitment, preoperatively, post-CPB, and 6, 12, and 24 hours postoperatively. The atorvastatin group showed a significantly higher amount of EPCs both pre- and postoperatively compared with the placebo, with a >4-fold increase compared with the baseline values. CPB induced an increase in all cytokines, but the levels of proinflammatory cytokines were significantly lower in the atorvastatin group (P < 0.05). Statin did not affect levels of SDF-1alpha, granulocyte colony-stimulating factor, and vascular endothelial growth factor. However, no correlation was found between plasma levels of any cytokine and number of EPCs, with the exception of SDF-1alpha. Pretreatment with atorvastatin significantly increases the amount of EPCs after CPB, by a mechanism independent of plasma levels of cytokines and cholesterol.

Background: Diabetic patients exhibit an increased risk of saphenous graft occlusion after coronary bypass. Advanced glycation end products (AGEs) are ubiquitous signalling proteins that are associated with vascular and neurological complication of diabetes. The aim of this study is to verify whether AGE levels may promote endothelial cell alterations responsible for vein graft failure., Methods: Segments of saphenous vein were obtained from both normal people and diabetic patients (HbA(1c) < 6.0%) at the time of coronary surgery. Cultured endothelial cells were incubated in the absence/presence of AGEs (2 and 20 microM), and mRNA and protein for both receptor of AGEs (RAGE) and peroxisome proliferator-activated receptors-gamma (PPAR-gamma) were analysed by real-time polymerised chain reaction (PCR) and Western blot analysis. In the same fashion, the cell release of reactive oxygen species (ROS) was estimated in the absence/presence of AGEs by spectrofluorimetric analysis. Finally, neutrophil-endothelial adhesion was evaluated in saphenous vein segments with and without the addition of AGEs., Results: AGEs activated in a dose-dependent manner the expression of RAGE and inhibited PPAR-gamma expression in endothelial cells as testified by both reverse transcription-PCR (RT-PCR) and Western blot analysis. Stimulation of cultured endothelial cells with AGEs significantly enhanced intracellular ROS formation in a dose-dependent manner. Finally, neutrophil-endothelial adhesion was significantly increased after incubation of control veins with AGEs., Conclusions: These findings indicate that even in diabetic patients with HbA(1c) < 6.0%, elevated serum levels of AGE determine a sort of a pro-thrombotic state, providing a common mechanism that could explain the increased rate of vein graft occlusion in this population.

Cartilage and bone tissue engineering has been widely investigated but is still hampered by cell differentiation and transplant integration issues within the constructs. Scaffolds represent the pivotal structure of the engineered tissue and establish an environment for neo-extracellular matrix synthesis. They can be associated to signals to modulate cell activity. In this study, considering the well reported role of hydroxyapatite (HA) in cartilage repair, we focused on the putative chondrogenic differentiation of human mesenchymal stem cells (hMSCs) following culture on membranes of electrospun fibers of poly-L-lactic acid (PLLA) loaded with nanoparticles of HA. hMSCs were seeded on PLLA/HA and bare PLLA membranes and cultured in basal medium, using chondrogenic differentiation medium as a positive control. After 14 days of culture, SOX-9 positive cells could be detected in the PLLA/HA group. Cartilage specific proteoglycan immunostain confirmed the presence of neo-extracellular-matrix production. Co-expression of CD29, a typical surface marker of MSCs and SOX-9, suggested different degrees in the differentiation process. We developed a hydroxyapatite functionalized scaffold with the aim to recapitulate the native histoarchitecture and the molecular signaling of osteochondral tissue to facilitate cell differentiation toward chondrocyte. PLLA/HA nanocomposites induced differentiation of hMSCs in a chondrocyte-like phenotype with generation of a proteoglycan based matrix. This nanocomposite could be an amenable alternative scaffold for cartilage tissue engineering using hMSCs.

Heart disease and atherosclerosis are the leading causes of morbidity and mortality worldwide. The lack of suitable autologous grafts has produced a need for artificial grafts; however, current artificial grafts carry significant limitations, including thrombosis, infection, limited durability and the inability to grow. Tissue engineering of blood vessels, cardiovascular structures and whole organs is a promising approach for creating replacement tissues to repair congenital defects and/or diseased tissues. In an attempt to surmount the shortcomings of artificial grafts, tissue-engineered cardiovascular graft (TECVG), constructs obtained using cultured autologous vascular cells seeded onto a synthetic biodegradable polymer scaffold, have been developed. Autologous TECVGs have the potential advantages of growth, durability, resistance to infection, and freedom from problems of rejection, thrombogenicity and donor scarcity. Moreover polymers engrafted with growth factors, cytokines, drugs have been developed allowing drug-releasing systems capable of focused and localized delivery of molecules depending on the environmental requirements and the milieu in which the scaffold is placed. A broad range of applications for compound-releasing, tissue-engineered grafts have been suggested ranging from drug delivery to gene therapy. This review will describe advances in the development of drug-delivery systems for cardiovascular applications focusing on the manufacturing techniques and on the compounds delivered by these systems to date.

Myocardial repair using stem-cell therapy has become a promising therapeutic tool. However, many questions concerning a precise functional integration of injected cells remain unanswered. The use of cardiac pre-committed cells may improve integration, as these cells may complete their differentiation in the myocardium reducing fibrosis and restoring muscle function. We have previously demonstrated that electrostimulation (ES) induces cardiomyocyte pre-commitment of fibroblasts in vitro and is an effective alternative to cytokine-induced differentiation. In this study, we evaluated the effects of long term electrostimulation on human mesenchymal stem cells (hMSCs). ES induced both morphological and biochemical changes in hMSCs resulting in a shift toward a striated muscle cell phenotype expressing cardiac specific markers. This partially differentiated phenotype might allow a gradual, ongoing differentiation within the cardiac environment, providing time for both myocardial regeneration and electro-mechanical integration, and convey potential advantages in clinical applications.

Background Aims: Follistatin (FST) and the related proteins FSTL1 and FSTL3 are crucial modulators of the transforming growth factor (TGF)-beta superfamily and function by neutralizing activins, a group of proteins implicated in many biologic processes, such as cell proliferation and differentiation, immune responses, various endocrine activities, wound repair, inflammation and fibrosis. Activins are increased in the serum of heart failure patients and in cardiomyocytes after experimental myocardial infarction, suggesting the involvement of activins in heart failure pathogenesis. FST is considered to be a key modulator in muscle development, differentiation and regeneration, and it has been implicated in the repair of mesodermal- and endodermal-derived tissues, promoting cell proliferation and hampering fibrogenesis. We have previously demonstrated that electrostimulation (ES) induces cardiomyocyte pre-commitment of both stem and non-stem cells in vitro. In this study, we evaluated whether applying ES to human mesenchymal stromal cells (hMSC) modulated FST production., Methods: hMSC were electrostimulated with 10 and 40 V for 12 h. FST production was assessed by immunostaining, Western blot and flow cytometry., Results: FST was up-regulated in hMSC after ES and was associated with cardiomyogenic differentiation of hMSC by short-term ES., Conclusions: The possibility of stimulating the production of FST, a key regulator of mesodermal differentiation, in adult stem cells, while avoiding the drawbacks of conditioned media, dangerous drugs and gene delivery, has relevant potential therapeutic clinical applications. Additionally, this simple differentiation system could be useful for elucidating the molecular mechanisms driving the stem cell-differentiation process.

Stem-cell therapy has become a promising therapeutic tool for myocardial repair. Cardiac pre-committed cells, which complete their differentiation in the myocardium, may reduce fibrosis and restore muscle function. However, many questions concerning a precise, functional integration of injected cells remain unanswered. Fibroblasts regulate the cardiac extracellular matrix and are the most abundant cell population in an infarcted area. Electrostimulation is a well-known trophic factor and can induce phenotypic changes in myoblasts. The objective of this study was to evaluate the effectiveness of electrical stimulation to induce pre-commitment of fibroblasts into cardiomyocytes in vitro. Using short-time electrostimulation in a cytokine-free culture system, we induced pre-commitment of two fibroblast cell lines to a cardiomyocyte phenotype. This partial differentiation in vitro may facilitate further differentiation within the cardiac environment and result in better electro-mechanical integration of the therapeutically introduced cells.

Objectives: To evaluate the relationship between CD40/CD40L system and increased thrombogenesis in AF, and to test the effects of simvastatin treatment., Methods: In vitro study using human tissue, University Hospital (tertiary referral center). Experiments on right atrial segments obtained before the onset of cardiopulmonary bypass were done in either presence or absence of 5 microM simvastatin. Two groups of patients in either chronic atrial fibrillation or sinus rhythm at the time of cardiac surgery. The endocardial expression of CD40, the release of CD40L, and adhesion of platelets to endocardium. Additionally, the thickness of platelet aggregates and the platelet distribution on the endocardium were also evaluated., Results: Atrial fibrillation was associated with a significant increase of endocardial CD40 expression (293.1+/-55.1 pg/ml vs. 230.9+/-53.3 pg/ml, p<0.01), and platelet-endocardial adhesion compared with sinus rhythm atria (10.8+/-2.2 vs. 5.2+/-1.3 platelet CD41 AU p<0.01). At immunofluorescence about 62% of fibrillating endocardium was covered by platelets, compared with 12% of not sinus rhythm atria. Addition of simvastatin significantly reduced CD40 expression as well as platelet adhesion to fibrillating atria; its efficacy was not reversed by the addition of mevalonic acid., Conclusions: Chronic atrial fibrillation acutely upregulates CD40 expression as well as platelet adhesion to the endocardium. Simvastatin is effective in modulating this expression, thus it may potentially contribute to reduce the risk of intra-atrial thrombus formation.

We report a case of a 76-year-old man complaining of dysphagia for solid food associated with a weight loss following an off-pump double vessel coronary artery revascularization. Multislice spiral computed tomography showed a 6 cm x 2.5 cm solid formation next to the posterior wall of the left atrium, adjacent to the pericardium and the right anterolateral side of the esophagus. The mass was confirmed to be an intramural esophageal hematoma by endoscopic ultrasound-guided fine-needle aspiration cytology. Injury to esophagus during the placement of deep pericardial sutures and postoperative infusion of heparin are claimed to be causes of this complication.

Background: Abnormal erythrocyte deformability can cause severe complications during cardiopulmonary bypass (CPB) surgery, including both hemolysis and perfusion abnormalities., Objectives: The goals of this study were to evaluate changes in erythrocyte membrane fluidity and lipid peroxidation during CPB and to examine the effect of simvastatin treatment on these parameters., Methods: Patients undergoing cardiac surgery involving CPB were selected and randomized to receive either simvastatin 40 mg/d or placebo for 3 weeks before surgery. Three blood samples were obtained at different times during surgery for analysis of erythrocyte membrane fluidity, anion permeability, and lipid peroxidation. Erythrocyte ghosts were prepared and incubated with a lipophilic fluorescent probe (diphenyl-hexatriene), and fluorescence anisotropy was evaluated by spectrophotofluorimetric assay as a measure of membrane fluidity. Anion permeability was evaluated by the specific absorption of methemoglobin (CM) at 590 and 635 nm after treatment of heparinized blood with NaNO2. The formation of thiobarbituric acid-reactive substances was evaluated as an index of lipid peroxidation. Aspartate transaminase and lactate dehydrogenase were also measured as indices of hemolysis., Results: Forty patients met the inclusion criteria (20 simvastatin, 20 placebo). Their characteristics differed significantly at baseline only in terms of the lipid profile; the statin group had higher levels of high-density lipoprotein cholesterol (P = 0.01) and lower levels of low-density lipoprotein cholesterol (P = 0.001) than the placebo group. CPB was found to significantly modify characteristics of the erythrocyte membrane. Compared with preoperative values, CPB induced decreases in both mean (SD) erythrocyte membrane fluidity and anion permeability (preoperative CM: 0.69 [0.02]; 24-hour postoperative CM: 0.18 [0.02]; P < 0.001) and an increase in mean (SD) membrane lipid peroxidation (preoperative malonyl dialdehyde [MDA]: 0.21 [0.01] nmol/mL; postoperative MDA: 0.10 [0.02] nmol/mL; P < 0.001). Treatment with simvastatin was associated with a significant reduction in mean (SD) membrane lipid peroxidation both preoperatively and at 24 hours postoperatively compared with placebo (preoperative MDA: 0.07 [0.01] vs 0.10 [0.02] nmol/mL, respectively; P < 0.05; postoperative MDA: 0.10 [0.04] vs 0.21 [0.01] nmol/mL; P < 0.05). In addition, statin treatment was associated with significant increases in anion permeability preoperatively and postoperatively compared with placebo (preoperative CM: 0.79 [0.01] vs 0.69 [0.02]; P < 0.01; 24-hour postoperative CM: 0.30 [0.01] vs 0.18 [0.02]; P < 0.01)., Conclusion: The results of this study suggest that among these patients undergoing CPB surgery, use of simvastatin for 3 weeks before the surgery had significant beneficial effects on erythrocyte membrane fluidity, lipid peroxidation, and anion permeability., (Copyright 2007 Excerpta Medica, Inc.)

Background: Neutrophils play a central role in systemic inflammatory reaction after cardiopulmonary bypass. Apoptosis is significantly delayed, and this might exacerbate systemic and myocardial damage. We tested the hypothesis of whether pretreatment with simvastatin increases the apoptotic rate of neutrophils and hence reduces the entity of inflammatory reaction., Methods: Thirty patients undergoing coronary surgery with cardiopulmonary bypass were randomized to treatment with either simvastatin (40 mg/day) or placebo for 3 weeks before surgery. A group of 15 patients undergoing off-pump coronary surgery served as controls. Blood samples for detection of serum cytokine levels were obtained before anesthesia, at the end of surgery, and at 4, 24, 48, and 72 hours postoperatively. Apoptosis and indices of activation were assessed in cultured neutrophils., Results: Simvastatin significantly reduced the postoperative peak values of interleukin (IL)-6 and IL-8. The neutrophil apoptotic rate was significantly higher among neutrophils obtained from patients pretreated with simvastatin (p < 0.05 at both 8 and 24 hours) compared with placebo. Neutrophils from the statin group had depressed functional activity, as underscored by significantly lower values of CD11b (p < 0.01 at 24 hours) and a significantly less percentage of cells positive for nitro-blue tetrazolium (p < 0.01 at 12 and 24 hours) compared with placebo., Conclusions: This randomized, double-blind study indicates that statin therapy before cardiopulmonary bypass is associated with reduction of circulating markers of inflammation and increased neutrophil apoptosis. These data support a routine inclusion of statins as an adjuvant pharmacologic therapy before cardiopulmonary bypass surgery.

Stem cell therapy has been used to treat ischemic cardiac disease with promising early results. However, there has been limited success using cell therapy in infarcted tissue. The cells have an inadequate microvascular environment in order to survive once implanted into scar tissue. The goal of this study was to create a microvascular environment into infarcted myocardial tissue using transmyocardial laser revascularization (TMR) as a pretreatment before cell implantation and evaluate cell survival afterwards. Balloon occlusion catheter-based myocardial infarct of the circumflex artery was created in a porcine model. The infarct was allowed to mature for 2 weeks. Three groups consisting of TMR alone (TMR), TMR + fluorescent-labeled allogeneic mesenchymal stem cells (MSCs) (TMR + Cells), and MSCs alone (Cells) were injected into the infarcted tissue using a combination TMR and cell delivery system (Phoenix, Cardiogenesis). The hearts were explanted at 1 week after treatment for cell and tissue evaluation. The myocardial infarcts were verified in all animals using both ultrasound and direct visual imaging. All arms of the study were successful with a mean of 2.0 +/- 10(6) MSCs injected per site into the scar tissue. All animals survived to explant at 1 week. On histological examination, 300 high-power fields were evaluated demonstrating that the TMR + Cells group had 25 +/- 5 cells and the Cells group 5 +/- 2 cells compared to baseline TMR alone by fluorescence. The use of TMR as a pretreatment for MSC injection increases early cell survival in infarcted tissue without increased adverse events. Further long-term functional and differentiation analysis will be required to evaluate the efficacy for future clinical translation.

Background: Saphenous vein graft (VG) failure occurs more frequently compared with arterial grafts, and graft thrombosis represents the main cause of early occlusion. Because CD40-CD40L pathway CD40 represents a culprit link between local inflammation and coagulation cascade, we investigate the role of CD40 and its soluble ligand (sCD40L) in the immediate in vitro response of VG to arterial pressures, and the potential effects of Simvastatin (Merck Sharp&Dohme, White-house Station, NJ) supplementation., Methods: Samples of saphenous vein and of internal mammary artery (IMA) were obtained from sixteen patients without history of statin therapy. Segments underwent pulsatile pressure distension and culture with or without supplementation of Simvastatin. CD40 and sCD40L were assessed in tissue lysate and in culture supernatant, respectively. sCD40L serum concentrations were also measured., Results: During the course of the experiment, the CD40 expression was significantly lower in IMA samples compared with both distended and not distended VG. Pressure distension up-regulated the production of CD40 in VG segments after 24 and 48 h. Statin supplementation significantly reduced the expression of CD40 in both venous (P < 0.001) and arterial samples (P < 0.001). This effect of Simvastatin was not affected by the treatment with L-NAME, but it was reversed by the addition of mevalonic acid. Mean sCD40L content in culture supernatants increased over time, suggesting that not only platelets but also the vessel wall is a source of CD40 and sCD40L., Conclusions: Simvastatin treatment modulates endothelial CD40-sCD40L in both venous and arterial grafts, and therefore may represent a useful tool in the pharmacological prevention of graft failure.