Inverse relationship between tumor proliferation markers and connexin expression in a malignant cardiac tumor originating from mesenchymal stem cell engineered tissue in a rat in vivo model

Recently, we demonstrated the beneficial effects of engineered heart tissues for the treatment of dilated cardiomyopathy in rats. For further development of this technique we started to produce engineered tissue (ET) from mesenchymal stem cells. Interestingly, we observed a malignant tumor invading the heart with an inverse relationship between proliferation markers and connexin expression

Surgical Therapy of Atrial Fibrillation

Atrial fibrillation (AF) can be found in an increasing number of cardiac surgical patients due to a higher patient's age and comorbidities. Atrial fibrillation is known, however, to be a risk factor for a greater mortality, and one aim of intraoperative AF treatment is to approximate early and long-term survival of AF patients to survival of patients with preoperative sinus rhythm. Today, surgeons are more and more able to perform less complex, that is, minimally invasive cardiac surgical procedures. The evolution of alternative ablation technologies using different energy sources has revolutionized the surgical therapy of atrial fibrillation and allows adding the ablation therapy without adding significant risk. Thus, the surgical treatment of atrial fibrillation in combination with the cardiac surgery procedure allows to improve the postoperative long-term survival and to reduce permanent anticoagulation in these patients. This paper focuses on the variety of incisions, lesion sets, and surgical techniques, as well as energy modalities and results of AF ablation and also summarizes future trends and current devices in use

Comprehensive assessment of frailty for elderly high-risk patients undergoing cardiac surgery

Objective: Cardiosurgical operative risk can be assessed using the logistic European system for cardiac operative risk evaluation (EuroSCORE) and the Society of Thoracic Surgeons (STS) score. Factors other than medical diagnoses and laboratory values such as the ‘biological age' are not included in these scores. The aim of the study was to evaluate an additional assessment of frailty in routine cardiac surgical practice. Methods: ‘The comprehensive assessment of frailty' test was applied to 400 patients ≥74 years who were admitted to our centre between September 2008 and January 2010. For comparison, the STS score and the EuroSCORE were calculated. The primary end point was the correlation of Frailty score to 30-day mortality. A total of 206 female and 194 male patients were included. Results: Median Frailty score was 11 [7,15]. Median of logistic EuroSCORE was 8.5% [5.8%; 13.9%]. Median of STS score was 3.3% [2.1%; 5.1%]. There were low-to-moderate albeit significant correlations of Frailty score with STS score and EuroSCORE (p≪0.05). There was also a significant correlation between Frailty score and observed 30-day mortality (p≪0.05). Patients received isolated coronary artery bypass grafting (CABG) (n=90), isolated valve surgery (n=128), trans-catheter valve implantation (n=59) or combined procedures (n=123). Conclusions: The comprehensive assessment of frailty is an additional tool to evaluate elderly patients adequately before cardiac surgical interventions. The Frailty score combines characteristics of the Fried criteria [1], of patient phenotype, of his physical performance and laboratory results. Further analysis on a larger patient population is warranted. A combination of the new Frailty score and the traditional scoring systems may facilitate a more accurate risk scoring in elderly high-risk patients scheduled for conventional cardiac surgery or trans-catheter aortic valve replacemen

Live broadcasting in cardiac surgery does not increase the operative risk

Objective: Live broadcasting of cardiac surgical procedures has an educational intention. There is an ongoing debate whether live surgery increases risk. Aim of this study was to evaluate the outcomes of patients who underwent a cardiac surgical procedure during live broadcasting. Methods: A total of 250 cardiac operations were performed during 32 live broadcastings at four different clinical sites between 1999 and 2009. Data on patient characteristics, intra-operative procedures and patient short- and long-term outcome were collected and analyzed. All participating centers complied with the rules for the conduct of live surgery developed by the European Association of Cardiovascular and Thoracic Surgery (EACTS) Techno College Committee. Results: Primary educational focus was the mitral valve in 126 cases, aortic valve including transcatheter valve implantations in 34, coronary artery bypass grafting (CABG) in 29, congenital in 26, aortic (ascending, arch, and descending) in 15, atrial fibrillation in 13, and heart failure in seven. Mean EuroSCORE (European System for Cardiac Operative Risk Evaluation) was 8.7±11.5 (range: 0.8-72). Thirty-day mortality was 1.2% (3/250): reasons for death were multi-organ failure in two and respiratory failure in one patient, respectively. Stroke rate was 2.4% (6/250). Five patients (2%) required cardiac re-operations within 30 days. The rate of mitral valve repair was 96% (121) and compares favourably with repair rates presented in national registries. Mean follow-up of all patients was 3.7±2.8 years with an estimated survival of 92% (95% confidence interval (CI): 87-95%) at 5 years. Conclusions: Based on this large experience there is no evidence for an excess perioperative risk for patients operated under the conditions of live broadcastin

Remodeling of cardiac passive electrical properties and susceptibility to ventricular and atrial arrhythmias

Coordinated electrical activation of the heart is essential for the maintenance of a regular cardiac rhythm and effective contractions. Action potentials spread from one cell to the next via gap junction channels. Because of the elongated shape of cardiomyocytes, longitudinal resistivity is lower than transverse resistivity causing electrical anisotropy. Moreover, non-uniformity is created by clustering of gap junction channels at cell poles and by non-excitable structures such as collagenous strands, vessels or fibroblasts. Structural changes in cardiac disease often affect passive electrical properties by increasing non-uniformity and altering anisotropy. This disturbs normal electrical impulse propagation and is, consequently, a substrate for arrhythmia. However, to investigate how these structural changes lead to arrhythmias remains a challenge. One important mechanism, which may both cause and prevent arrhythmia, is the mismatch between current sources and sinks. Propagation of the electrical impulse requires a sufficient source of depolarizing current. In the case of a mismatch, the activated tissue (source) is not able to deliver enough depolarizing current to trigger an action potential in the non-activated tissue (sink). This eventually leads to conduction block. It has been suggested that in this situation a balanced geometrical distribution of gap junctions and reduced gap junction conductance may allow successful propagation. In contrast, source-sink mismatch can prevent spontaneous arrhythmogenic activity in a small number of cells from spreading over the ventricle, especially if gap junction conductance is enhanced. Beside gap junctions, cell geometry and non-cellular structures strongly modulate arrhythmogenic mechanisms. The present review elucidates these and other implications of passive electrical properties for cardiac rhythm and arrhythmogenesis

Beating-heart implantation of adjustable length mitral valve chordae: acute and chronic experience in an animal model

Objective: This study aimed to determine the acute and chronic performance of a new system designed to conduct beating-heart implantation and off-pump adjustment of neochordal length. Methods: In 14 adult sheep (group A) selected to undergo beating-heart cardiopulmonary bypass, the left atrium was opened through a left thoracotomy. Two or more primary chordae in the A2 region were severed to produce a model of a flail leaflet. A chordal adjustment mechanism (V-Chordal, Valtech Cardio Ltd., Or-Yehuda, Israel) was affixed to the head of the papillary muscle. The system includes two adjustable neochordae. The distal end of the neochordae was sutured to the flail segment without estimating the appropriate length. The neochordal length was adjusted off-pump under real-time echo-guidance. The adjustment tool was removed and the atriotomy was closed with a purse-string suture. Control animals (group B, n=4) were implanted with the conventional neochordae. Animals in both groups were sacrificed 3 months after the procedure. Results: In both groups, prior to repair, mitral regurgitation (MR) was severe in all animals. In group A, following adjustment of neochordae, MR was absent in all animals, with the exception of two animals that had residual 2+ MR irresponsive to neochordae adjustments. In group B, MR was 2+ in two of the four animals following repair. At 3 months, mitral competence was stable in all animals. At necropsy, normal healing of the papillary head and leaflet was observed in both the groups. Conclusions: The V-Chordal system simplifies the process of neochordal implantation and precise off-pump adjustment of the neochordal length to correct MR occurring due to a flail leaflet. This technology may improve the technical feasibility for adoption of chordal repair during open or minimally invasive surgical procedure

Access to

The shortage of appropriate donor organs and the expanding pool of patients waiting for heart transplantation have led to growing interest in alternative strategies, particularly in mechanical circulatory support. Improved results and the increased applicability and durability with left ventricular assist devices (LVADs) have enhanced this treatment option available for end-stage heart failure patients. Moreover, outcome with newer pumps have evolved to destination therapy for such patients. Currently, results using nonpulsatile continuous flow pumps document the evolution in outcomes following destination therapy achieved subsequent to the landmark Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure Trial (REMATCH), as well as the outcome of pulsatile designed second-generation LVADs. This review describes the currently available types of LVADs, their clinical use and outcomes, and focuses on the patient selection process

Distribution of Cardiac Stem Cells in the Human Heart

Introduction. The existence of human cardiac stem cells (hCSC) and their regenerative capacity are not fully defined. The aim of this study was to identify and analyse the distribution of hCSCs by flow cytometry (FCM). Methods. Tissue samples from the left ventricle (LV) and the appendages of the right atrium (RA) and left atrium (LA) were taken during cardiac surgery. Mononuclear cells (MNCs) were isolated, labelled for the stem-cell-marker c-kit and hematopoietic-lineage markers and analysed by FCM. Results. HCSCs could be isolated from the RA, LA, and LV without significant quantitative difference between both atria (A) (RA 4.80 ± 1.76% versus LA 4.99 ± 1.69% of isolated MNCs, P = 0.922). The number of hCSCs was significantly higher in both atria compared to the left ventricle (A 4.90 ± 1.29% versus LV 0.62 ± 0.14% of isolated MNCs, P = 0.035). Conclusion. The atria contain a higher concentration of hCSC than the left ventricle. HCSCs located in the atria could serve as an endogenous source for heart regeneration

Current Indications for Surgical Repair in Patients with Bicuspid Aortic Valve and Ascending Aortic Ectasia

Preventive surgical repair of the moderately dilated ascending aorta/aortic root in patients with bicuspid aortic valve (BAV) is controversial. Most international reference centers are currently proposing a proactive approach for BAV patients with a maximum ascending aortic/root diameter of 45 mm since the risk of dissection/rupture raises significantly with an aneurysm diameter >50 mm. Current guidelines of the European Society of Cardiology (ESC) and the joint guidelines of the American College of Cardiology (ACC)/American Heart Association (AHA) recommend elective repair in symptomatic patients with dysfunctional BAV (aortic diameter ≥45 mm). In asymptomatic patients with a well-functioning BAV, elective repair is recommended for diameters ≥50 mm, or if the aneurysm is rapidly progressing (rate of 5 mm/year), or in case of a strong family history of dissection/rupture/sudden death, or with planned pregnancy. As diameter is likely not the most reliable predictor of rupture and dissection and the majority of BAV patients may never experience an aortic catastrophe at small diameters, an overly aggressive approach almost certainly will put some patients with BAV unnecessarily at risk of operative and early mortality. This paper discusses the indications for preventive, elective repair of the aortic root, and ascending aorta in patients with a BAV and a moderately dilated—or ectatic—ascending aorta