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Abstract Left atrial intramural hematoma is a seldom cause of left atrial mass. It has been described to occur spontaneously, after interventional procedures, after blunt chest trauma, or after aortocoronary bypass surgery. We present a case of mitral valve replacement together with the removal of a large intraatrial space-occupying lesion. Intraoperative transesophageal echocardiography confirmed a successful resection of this mass. Surprisingly, upon admission to ICU, transesophageal and transthoracic echocardiography revealed a recurrence of an intramural lesion, closest matching a hematoma, which was confirmed by contrast-enhanced computed tomography. Surgical intervention was thoroughly discussed but a conservative management was favoured. 3 months after surgery, a reassessed transthoracic echocardiography and computed tomography demonstrated an almost complete resolution of the pre-existing hematoma.

Abstract Background Since 2002 MI and stroke, not cancer, are leading causes of death in women. We studied 30-days and 1 year mortality of 3441 patients undergoing coronary artery bypass grafting (CABG) operations in our institution performed either conventionally or off pump (OPCAB). Our objective was to investigate the gender-related mortality in both groups. Patients and Methods Between 2004 and 2008, 3441 patients (733 women, 2708 men) underwent CABG. 252 women and 854 men were operated using OPCAB, 481 women and 1854 men using extracorporeal circulation (ECC). Medical data was prospectively entered and retrospectively reviewed. 30-days and one year mortality rates were analyzed with Kaplan-Meier estimates and Cox proportional hazards models. Linear and logistic regression models were used to test gender differences. Results a) 30-day mortality using ECC: 5.2% in women vs. 2.5% in men (p = 0.001). One year ECC mortality: 8.7% in women vs. 4.8% in men (p = 0.0008). b) OPCAB: 30-days and 1 year mortality in women measured 1.7%. Mortality in men was 2.1% after 30 days and 3.7% after one year c) gender specific mortality: 30 days mortality in women was 1.7% using OPCAB and 5.2% using ECC (p = 0.002), one year mortality in women was 1.7% using OPCAB vs. 8.7% using ECC (p = 0.0004). In men, 30-days mortality in OPCAB was 2.1%, one year mortality was 3.7%; using ECC early and late mortality was 2.5% and 4.8%. Conclusions Female gender is a strong independent predictor and risk factor of increased early and midterm postoperative mortality rates when ECC is used. OPCAB significantly reduces early and midterm postoperative mortality in women and may therefore be proposed as the preferred revascularization technique in female patients.

Abstract Introduction Coronary artery disease progression after primary coronary artery bypass grafting may, beside classical atherosclerosis risk factors, be depending on genetic predisposition. Methods We investigated 192 CABG patients (18% female, age: 60.9 ± 7.4 years). Clinically cardiac adverse events were defined as need for reoperation (n = 88; 46%), reintervention (n = 58; 30%), or angina (n = 89; 46%). Mean follow-up time measured 10.1 ± 5.1 years. Gene polymorphisms (ApoE, NOS3, LIPC, CETP, SERPINE-1, Prothrombin) were investigated separately and combined (gene risk profile). Results Among classical risk factors, arterial hypertension and hypercholesterinemia significantly influenced CAD progression. Single ApoE, NOS3 and LIPC polymorphisms provided limited information. Patients missing the most common ApoE ε3 allele (5,2%), showed recurrent symptoms (p = 0,077) and had more frequently reintervention (p = 0,001). NOS3 a allele was associated with a significant increase for reintervention (p = 0,041) and recurrent symptoms (p = 0,042). Homozygous LIPC patients had a higher reoperation rate (p = 0.049). A gene risk profile enabled us to discriminate between faster and slower occurrence of cardiac adverse events (p = 0.0012). Conclusion Single APOE, LIPC and NOS3 polymorphisms permitted limited prognosis of cardiac adverse events in patients after CABG. Risk profile, in contrast, allowed for risk stratification.

Background: Many genetically multi‐modified donor lines for xenotransplantation have a background of domestic pigs with rapid body and organ growth. The intrinsic growth potential of porcine xeno‐organs may impair their long‐term function after orthotopic transplantation in non‐human primate models. Since growth hormone is a major stimulator of postnatal growth, we deleted its receptor (GHR‐KO) to reduce the size of donor pigs in one step. Methods: Heart weight and proteome profile of myocardium were investigated in GHR‐KO and control pigs. GHR‐KO mutations were introduced using CRISPR/Cas9 in an α1,3‐galactosyltransferase (GGTA1)‐deficient background expressing the human cluster of differentiation (hCD46) and human thrombomodulin (hTHBD) to generate quadruple‐modified (4GM) pigs. Results: At age 6 months, GHR‐KO pigs had a 61% reduced body weight and a 63% reduced heart weight compared with controls. The mean minimal diameter of cardiomyocytes was 28% reduced. A holistic proteome study of myocardium samples from the two groups did not reveal prominent differences. Two 4GM founder sows had low serum insulin‐like growth factor 1 (IGF1) levels (24 ± 1 ng/mL) and reached body weights of 70.3 and 73.4 kg at 9 months. Control pigs with IGF1 levels of 228 ± 24 ng/mL reached this weight range three months earlier. The 4GM sows showed normal sexual development and were mated with genetically multi‐modified boars. Offspring revealed the expected Mendelian transmission of the genetic modifications and consistent expression of the transgenes. Conclusion: GHR‐KO donor pigs can be used at an age beyond the steepest phase of their growth curve, potentially reducing the problem of xeno‐organ overgrowth in preclinical studies. [ABSTRACT FROM AUTHOR]

Background: Successful preclinical transplantations of porcine hearts into baboon recipients are required before commencing clinical trials. Despite years of research, over half of the orthotopic cardiac xenografts were lost during the first 48 hours after transplantation, primarily caused by perioperative cardiac xenograft dysfunction (PCXD). To decrease the rate of PCXD, we adopted a preservation technique of cold non‐ischemic perfusion for our ongoing pig‐to‐baboon cardiac xenotransplantation project. Methods: Fourteen orthotopic cardiac xenotransplantation experiments were carried out with genetically modified juvenile pigs (GGTA1‐ KO/hCD46/hTBM) as donors and captive‐bred baboons as recipients. Organ preservation was compared according to the two techniques applied: cold static ischemic cardioplegia (IC; n = 5) and cold non‐ischemic continuous perfusion (CP; n = 9) with an oxygenated albumin‐containing hyperoncotic cardioplegic solution containing nutrients, erythrocytes and hormones. Prior to surgery, we measured serum levels of preformed anti‐non‐Gal‐antibodies. During surgery, hemodynamic parameters were monitored with transpulmonary thermodilution. Central venous blood gas analyses were taken at regular intervals to estimate oxygen extraction, as well as lactate production. After surgery, we measured troponine T and serum parameters of the recipient's kidney, liver and coagulation functions. Results: In porcine grafts preserved with IC, we found significantly depressed systolic cardiac function after transplantation which did not recover despite increasing inotropic support. Postoperative oxygen extraction and lactate production were significantly increased. Troponin T, creatinine, aspartate aminotransferase levels were pathologically high, whereas prothrombin ratios were abnormally low. In three of five IC experiments, PCXD developed within 24 hours. By contrast, all nine hearts preserved with CP retained fully preserved systolic function, none showed any signs of PCXD. Oxygen extraction was within normal ranges; serum lactate as well as parameters of organ functions were only mildly elevated. Preformed anti‐non‐Gal‐antibodies were similar in recipients receiving grafts from either IC or CP preservation. Conclusions: While standard ischemic cardioplegia solutions have been used with great success in human allotransplantation over many years, our data indicate that they are insufficient for preservation of porcine hearts transplanted into baboons: Ischemic storage caused severe impairment of cardiac function and decreased tissue oxygen supply, leading to multi‐organ failure in more than half of the xenotransplantation experiments. In contrast, cold non‐ischemic heart preservation with continuous perfusion reliably prevented early graft failure. Consistent survival in the perioperative phase is a prerequisite for preclinical long‐term results after cardiac xenotransplantation. [ABSTRACT FROM AUTHOR]

The activation of the endothelial surface in xenografts is still a poorly understood process and the consequences are unpredictable. The role of Ca2+‐messaging during the activation of endothelial cells is well recognized and routinely measured by synthetic Ca2+‐sensitive fluorophors. However, these compounds require fresh loading immediately before each experiment and in particular when grown in state‐of‐the‐art 3D cell culture systems, endothelial cells are difficult to access with such sensors. Therefore, we developed transgenic pigs expressing a Ca2+‐sensitive protein and examined its principal characteristics. Primary transgenic endothelial cells stimulated by ATP showed a definite and short influx of Ca2+ into the cytosol, whereas exposure to human serum resulted in a more intense and sustained response. Surprisingly, not all endothelial cells reacted identically to a stimulus, rather activation took place in adjacent cells in a timely decelerated way and with distinct intensities. This effect was again more pronounced when cells were stimulated with human serum. Finally, we show clear evidence that antibody binding alone significantly activated endothelial cells, whereas antibody depletion dramatically reduced the stimulatory potential of serum. Transgenic porcine endothelial cells expressing a Ca2+‐sensor represent an interesting tool to dissect factors inducing activation of porcine endothelial cells after exposure to human blood or serum. [ABSTRACT FROM AUTHOR]

Background: Transpulmonary thermodilution is well established as a tool for in‐depth hemodynamic monitoring of critically ill patients during surgical procedures and intensive care. It permits easy assessment of graft function following cardiac transplantation and guides post‐operative volume and catecholamine therapy. Since no pulmonary catheter is needed, transpulmonary thermodilution could be useful in experimental cardiac pig‐to‐baboon xenotransplantation. However, normal values for healthy animals have not yet been reported. Here, we present data from piglets and baboons before xenotransplantation experiments and highlight differences between the two species and human reference values. Methods: Transpulmonary thermodilution from baboons (body weight 10‐34 kg) and piglets (body weight 10‐38kg) were analyzed. Measurements were taken in steady state after induction of general anesthesia before surgical procedures commenced. Cardiac index (CI), mean arterial pressure (MAP), systemic vascular resistance index (SVRI), parameters quantifying cardiac filling (global end‐diastolic volume index, GEDI), and pulmonary edema (extravascular lung water, ELWI) were assessed. Results: Preload, afterload, and contractility parameters clearly correlated with total body weight or body surface area. Baboons had lower CI values than weight‐matched piglets (4.2 ± 0.9l/min/m2 vs 5.3 ± 1.0/min/m2, P <.01). MAP and SVRI were higher in baboons than piglets (MAP: 99 ± 22 mm Hg vs 62 ± 11 mm Hg, P <.01; SVRI: 1823 ± 581 dyn*s/cm5*m2 vs 827 ± 204 dyn*s/cm5*m2, P <.01). GEDI and ELWI did differ significantly between both species, but measurements were within similar ranges (GEDI: 523 ± 103 mL/m2 vs 433 ± 78 mL/m2, P <.01; ELWI: 10 ± 3 mL/kg vs 11 ± 2 mL/kg, P <.01). Regarding adult human reference values, CI was similar to both baboons and piglets, but all other parameters were different. Conclusions: Parameters of preload, afterload, and contractility differ between baboons and piglets. In particular, baboons have a much higher afterload than piglets, which might be instrumental in causing perioperative xenograft dysfunction and post‐operative myocardial hypertrophy after orthotopic pig‐to‐baboon cardiac xenotransplantation. Most transpulmonary thermodilution‐derived parameters obtained from healthy piglets and baboons lie outside the reference ranges for humans, so human normal values should not be used to guide treatment in those animals. Our data provide reference values as a basis for developing algorithms for perioperative hemodynamic management in pig‐to‐baboon cardiac xenotransplantation. [ABSTRACT FROM AUTHOR]

Background Existing large-animal, ex vivo, cardiac perfusion models are restricted in their ability to establish an ischemia/reperfusion condition as seen in cardiac surgery or transplantation. Other working heart systems only challenge one ventricle or require a substantially larger priming volume.We describe a novel biventricular cardiac perfusion system with reduced priming volume. Methods Juvenile pig hearts were cardiopleged, explanted, and reperfused ex vivo after 150 minutes of cold ischemia. Autologous whole blood was used as perfusate (minimal priming volume 350 mL). After 15 minutes of Langendorff perfusion (LM), the system was switched into a biventricular working mode (WM) and studied for 3 hours. Results During reperfusion, complete unloading of both ventricles and constantpressure coronary perfusion was achieved. During workingmode perfusion, the preload and afterload pressure of both ventricles was controlled within the targeted physiologic range. Functional parameters such as left ventricular work index were reduced in ex vivo working mode (in vivo: 787 ± 186 vs. 1 h WM 498 ± 66 mm Hg·mL/g·min; p < 0.01), but remained stable throughout the following study period (3 h WM 517 ± 103 mm Hg·mL/g·min; p ¼ 0.63). Along with the elevated workload during WM, myocardial metabolism and oxygen consumption increased compared with LM (0.021 ± 0.08 vs. 0.06 ± 0.01 mL/min/g; 1 h after reperfusion). Histologic examination of the myocardium revealed no structural damage. Conclusion In the ex vivo perfusion system, stable hemodynamic and metabolic conditions can be established for a period of 3 hours while functional and blood parameters are easily accessible.Moreover, because of the minimal priming volume, the novel ex vivo cardiac perfusion circuit allows for autologous perfusion, using the limited amount of blood available from the organ donating animal. [ABSTRACT FROM AUTHOR]

Abstract: Background: Regulatory T cells (Treg) play an important role in maintenance of homeostasis in vivo. Treg application to alleviate allo‐organ rejection is being studied extensively. However, natural Treg (nTreg) expansion in vitro is laborious and expensive. Antigen‐specific Treg are more effective and require lower cell numbers than use of nTreg for immune control. The baboon, as a non‐human primate experimental animal model, is widely used in xenotransplantation research. An effective method to generate baboon xeno‐specific Treg would benefit research on immune tolerance in xenotransplantation using this model system. Method: Baboon tolerogenic dendritic cells (tolDC) were generated in 3 days from monocytes isolated from baboon peripheral blood mononuclear cells in medium supplemented with anti‐inflammatory cytokines. After loading with porcine‐specific (PS) in vitro‐transcribed RNA (ivtRNA), tolDC were used to induce CD4+ T cells to become porcine‐specific Treg (PSTreg) in cocultures supplemented with IL‐2 and rapamycin for 10 days. Anti‐inflammatory and inflammatory cytokine expression was evaluated at the mRNA and protein levels in both baboon tolDC and PSTreg. Functional assays, suppression of activation markers on porcine‐specific effector T cells (PSTeff) and inhibition of PSTeff proliferation, were used to test PSTreg specificity. Results: TolDC generated with this method exhibited a tolerogenic phenotype, expressed CCR7 and produced high levels of IL‐10 and TGF‐β1, whereas IL‐12p40 and IFN‐γ were not expressed. PSTreg were successfully generated in cocultures of CD4+ T cells and PS ivtRNA‐loaded tolDC. They exhibited a CD3+ CD4+ CD25+ CD127low/− CD45RAlow Foxp3+ phenotype and were characterized by high expression of IL‐10 and TGF‐β1 mRNA and protein. They showed upregulated expression of EBI3 and GARP mRNA. PSTreg exhibited highly suppressive effects toward PSTeff, secreting high amounts of IL‐10 and TGF‐β1 cytokine upon interaction with PSTeff and suppressing IFN‐γ expression on PSTeff. Conclusion: In this study, a fast 3‐day method to generate baboon‐derived tolDC is provided that allows subsequent induction of PSTreg displaying high porcine‐antigen specificity and expression of IL‐10 and TGF‐β1. Porcine‐specific baboon Treg can be used in porcine solid organ or cell xenotransplantation studies through adoptive cell transfer into host baboons. [ABSTRACT FROM AUTHOR]