The role of coronary artery disease in lung transplantation: a propensity-matched analysis.

BACKGROUND AND AIMS: Candidate selection for lung transplantation (LuTx) is pivotal to ensure individual patient benefit as well as optimal donor organ allocation. The impact of coronary artery disease (CAD) on post-transplant outcomes remains controversial. We provide comprehensive data on the relevance of CAD for short- and long-term outcomes following LuTx and identify risk factors for mortality. METHODS: We retrospectively analyzed all adult patients (≥ 18 years) undergoing primary and isolated LuTx between January 2000 and August 2021 at the LMU University Hospital transplant center. Using 1:1 propensity score matching, 98 corresponding pairs of LuTx patients with and without relevant CAD were identified. RESULTS: Among 1,003 patients having undergone LuTx, 104 (10.4%) had relevant CAD at baseline. There were no significant differences in in-hospital mortality (8.2% vs. 8.2%, p > 0.999) as well as overall survival (HR 0.90, 95%CI [0.61, 1.32], p = 0.800) between matched CAD and non-CAD patients. Similarly, cardiovascular events such as myocardial infarction (7.1% CAD vs. 2.0% non-CAD, p = 0.170), revascularization by percutaneous coronary intervention (5.1% vs. 1.0%, p = 0.212), and stroke (2.0% vs. 6.1%, p = 0.279), did not differ statistically between both matched groups. 7.1% in the CAD group and 2.0% in the non-CAD group (p = 0.078) died from cardiovascular causes. Cox regression analysis identified age at transplantation (HR 1.02, 95%CI [1.01, 1.04], p < 0.001), elevated bilirubin (HR 1.33, 95%CI [1.15, 1.54], p < 0.001), obstructive lung disease (HR 1.43, 95%CI [1.01, 2.02], p = 0.041), decreased forced vital capacity (HR 0.99, 95%CI [0.99, 1.00], p = 0.042), necessity of reoperation (HR 3.51, 95%CI [2.97, 4.14], p < 0.001) and early transplantation time (HR 0.97, 95%CI [0.95, 0.99], p = 0.001) as risk factors for all-cause mortality, but not relevant CAD (HR 0.96, 95%CI [0.71, 1.29], p = 0.788). Double lung transplant was associated with lower all-cause mortality (HR 0.65, 95%CI [0.52, 0.80], p < 0.001), but higher in-hospital mortality (OR 2.04, 95%CI [1.04, 4.01], p = 0.039). CONCLUSION: In this cohort, relevant CAD was not associated with worse outcomes and should therefore not be considered a contraindication for LuTx. Nonetheless, cardiovascular events in CAD patients highlight the necessity of control of cardiovascular risk factors and a structured cardiac follow-up.

The Effects of the Levosimendan Metabolites OR-1855 and OR-1896 on Endothelial Pro-Inflammatory Responses.

The calcium sensitizer levosimendan is used for the treatment of acute decompensated heart failure. A small portion (4-7%) of levosimendan is metabolized to the pharmacologically active metabolite OR-1896 via the inactive intermediate OR-1855. In addition, levosimendan has been shown to exert positive effects on the endothelium in vitro antagonizing vascular dysfunction and inflammation. However, the function of the levosimendan metabolites within this context is still unknown. In this study, we thus investigated the impact of the metabolites OR-1896 and OR-1855 on endothelial inflammatory processes in vitro. We observed a reduction of IL-1ß-dependent endothelial adhesion molecule ICAM-1 and VCAM-1 as well as interleukin (IL) -6 expression upon levosimendan treatment but not after treatment with OR-1855 or OR-1896, as assessed by western blotting, flow cytometry, and qRT-PCR. Instead, the metabolites impaired IL-1ß-induced ROS formation via inactivation of the MAPK p38, ERK1/2, and JNK. Our results suggest that the levosimendan metabolites OR-1896 and OR-1855 have certain anti-inflammatory properties, partly other than levosimendan. Importantly, they additionally show that the intermediate metabolite OR-1855 does, in fact, have pharmacological effects in the endothelium. This is interesting, as the metabolites are responsible for the long-term therapeutic effects of levosimendan, and heart failure is associated with vascular dysfunction and inflammation.

Influence of dental status on outcome after lung transplantation.

INTRODUCTION: Poor oral hygiene can cause infections and inflammatory diseases. Data on its impact on outcome after lung transplantation (LuTX) is scarce. Most transplant centers have individual standards regarding dental care as there is no clinical guideline. This study's objective was to assess LuTX-listed patient's dental status and determine its effect on postoperative outcome. METHODS: Two hundred patients having undergone LuTX from 2014 to 2019 were selected. Collected data comprised LuTX-indication, periodontal status, and number of carious teeth/fillings. A preoperative panoramic dental X-ray and a dentist's consultative clarification were mandatory. RESULTS: 63.5% had carious dental status, differing significantly regarding TX-indication (p < 0.001; ILD: 41.7% vs. CF: 3.1% of all patients with carious teeth). Mean age at the time of LuTX differed significantly within these groups. Neither preoperative carious dental status nor periodontitis or bone loss deteriorated post-LuTX survival significantly. No evidence was found that either resulted in a greater number of deaths related to an infectious etiology. CONCLUSION: This study shows that carious dental status, periodontitis, and bone loss do not affect post-TX survival. However, literature indicates that they can cause systemic/pulmonary infections that deteriorate post-LuTX survival. Regarding the absence of standardized guidelines regarding dental care and LuTX, we strongly recommend emphasizing research in this field.

Optimized Conditions for the Long-Term Maintenance of Precision-Cut Murine Myocardium in Biomimetic Tissue Culture.

Organotypic heart slices from mice might provide a promising in vitro model for cardiac research because of the vast availability of genetically modified specimens, combined with the unrestricted feasibility of experimental interventions. However, murine heart slices undergo rapid degeneration in culture. Therefore, we developed optimal conditions to preserve their structure and function in culture. Mouse ventricular heart samples were transversely cut into 300 µm thick slices. Slices were then cultured under various conditions of diastolic preload, systolic compliance and medium agitation. Continuous stimulation was performed either by optical stimulation or by electrical field stimulation. Contractility was continuously measured, and cellular survival, structure and gene expression were analyzed. Significant improvements in viability and function were achieved by elastic fixation with the appropriate diastolic preload and the rapid shaking of a ß-mercaptoethanol-supplemented medium. At 1 Hz pacing, mouse heart slices maintained stable contractility for up to 48 h under optogenetic pacing and for one week under electrical pacing. In cultured slices, the native myofibril structure was well preserved, and the mRNAs of myosin light chain, titin and connexin 43 were constantly expressed. Conclusions: Adult murine heart slices can be preserved for one week and provide a new opportunity to study cardiac functions.

The RAPID-score: Risk Assessment and PredIction of Delirium in acute stroke patients based on very early clinical parameters.

Background and objective: Post-stroke delirium (PSD) is a common complication in acute stroke patients, and guidelines recommend routine screening and various preventive and treatment measures. However, there is a substantial lack of standardized approaches in diagnostic and therapeutic management of PSD. Here, we aimed to develop a new pragmatic and easily assessable screening tool to predict PSD based on early parameters, which are already integral to acute stroke diagnostics. Methods: We enrolled acute stroke patients admitted to our stroke unit or intensive care unit and developed the scoring system using retrospective single-center patient data. The Confusion Assessment Method for the Intensive Care Unit was used for prospective score validation. Logistic regression models were employed to analyze the association of early clinical and paraclinical parameters with PSD development. Results: N = 525 patients (median age: 76 years; 45.7% female) were enrolled, with 29.7% developing PSD during hospitalization. The resulting score comprises 6 items, including medical history, clinical examination findings, and non-contrast computed tomography results at admission. Scores range from -15 to +15 points, with higher values indicating a higher likelihood of PSD, ranging from 4% to 79%. The accuracy was 0.85, and the area under the curve was 0.89. Conclusion: The new RAPID (Risk Assessment and PredIction of Delirium in acute stroke patients)-score shows high accuracy in predicting PSD among acute stroke patients and offers precise odds of PSD for each corresponding score value, utilizing routine early clinical and paraclinical parameters. It can identify high-risk populations for clinical study interventions and may be suitable to guide prophylactic PSD measures.

A Functional Network Driven by MicroRNA-125a Regulates Monocyte Trafficking in Acute Inflammation.

During the onset of acute inflammation, rapid trafficking of leukocytes is essential to mount appropriate immune responses towards an inflammatory insult. Monocytes are especially indispensable for counteracting the inflammatory stimulus, neutralising the noxa and reconstituting tissue homeostasis. Thus, monocyte trafficking to the inflammatory sites needs to be precisely orchestrated. In this study, we identify a regulatory network driven by miR-125a that affects monocyte adhesion and chemotaxis by the direct targeting of two adhesion molecules, i.e., junction adhesion molecule A (JAM-A), junction adhesion molecule-like (JAM-L) and the chemotaxis-mediating chemokine receptor CCR2. By investigating monocytes isolated from patients undergoing cardiac surgery, we found that acute yet sterile inflammation reduces miR-125a levels, concomitantly enhancing the expression of JAM-A, JAM-L and CCR2. In contrast, TLR-4-specific stimulation with the pathogen-associated molecular pattern (PAMP) LPS, usually present within the perivascular inflamed area, resulted in dramatically induced levels of miR-125a with concomitant repression of JAM-A, JAM-L and CCR2 as early as 3.5 h. Our study identifies miR-125a as an important regulator of monocyte trafficking and shows that the phenotype of human monocytes is strongly influenced by this miRNA, depending on the type of inflammatory stimulus.

Simultaneous LC-ESI-MS/MS Quantification of Levosimendan and Its Metabolites for Therapeutic Drug Monitoring of Cardiac Surgery Patients.

Levosimendan is used in severe chronic cardiac insufficiency, also within the peri-operative setting. Real-life pharmacokinetic data in surgical patients is lacking, making therapeutic drug monitoring (TDM) of levosimendan, its pharmacologically active metabolite OR-1896, and its intermediate OR-1855 important. A simultaneous highly sensitive quantification of levosimendan and its metabolites in small-volume samples has not yet been described. Here, levosimendan (LLOQ 0.450 nM), OR-1896, and OR-1855 (LLOQ both 1.0 nM) were successfully quantified by LC-ESI-MS/MS after liquid-liquid extraction in 300 µL of blood. A short C8 column under reversed-phase conditions enabled simultaneous and fast quantification of levosimendan in the negative and the metabolites in the positive ionization mode in a single run within 2 min. Interestingly and unexpectedly, constitutional isomers of levosimendan metabolites with identical mass transitions and similar retention times were observed in surgical patients' samples, which we identified as the metamizole metabolites 4-aminoantipyrine and 4-acetamidoantipyrine. A longer C8 column and a modified mobile phase enabled selective quantification of all analytes in a single run within 7 min. We developed, validated, and applied highly sensitive LC-ESI-MS/MS methods for simultaneous quantification of levosimendan and its metabolites, enabling efficient TDM of cardiac surgery patients even with additional metamizole administration.

Migratory and anti-fibrotic programmes define the regenerative potential of human cardiac progenitors.

Heart regeneration is an unmet clinical need, hampered by limited renewal of adult cardiomyocytes and fibrotic scarring. Pluripotent stem cell-based strategies are emerging, but unravelling cellular dynamics of host-graft crosstalk remains elusive. Here, by combining lineage tracing and single-cell transcriptomics in injured non-human primate heart biomimics, we uncover the coordinated action modes of human progenitor-mediated muscle repair. Chemoattraction via CXCL12/CXCR4 directs cellular migration to injury sites. Activated fibroblast repulsion targets fibrosis by SLIT2/ROBO1 guidance in organizing cytoskeletal dynamics. Ultimately, differentiation and electromechanical integration lead to functional restoration of damaged heart muscle. In vivo transplantation into acutely and chronically injured porcine hearts illustrated CXCR4-dependent homing, de novo formation of heart muscle, scar-volume reduction and prevention of heart failure progression. Concurrent endothelial differentiation contributed to graft neovascularization. Our study demonstrates that inherent developmental programmes within cardiac progenitors are sequentially activated in disease, enabling the cells to sense and counteract acute and chronic injury.

Oxygenated Hemoglobin Predicts Outcome in Patients with Chronic Lung Allograft Dysfunction.

BACKGROUND: Long-term outcome of lung transplantation (LTx) recipients is limited by chronic lung allograft dysfunction (CLAD). In this setting of new onset respiratory failure, the amount of oxygenated hemoglobin (OxyHem; hemoglobin (Hb) concentration × fractional oxygen saturation) may provide valuable information. OBJECTIVE: We hypothesized that OxyHem predicts survival of LTx recipients at the onset of CLAD. METHODS: Data from 292 LTx recipients with CLAD were analyzed. After excluding patients with missing data or supplemental oxygen, the final population comprised 218 patients. The relationship between survival upon CLAD and OxyHem was analyzed by Cox regression analyses and ROC curves. RESULTS: Among the 218 patients (102 males, 116 females), 128 (58.7%) died, median survival time after CLAD onset being 1,156 days. Survival was significantly associated with type of transplantation, time to CLAD, CLAD stage at onset, and OxyHem, which was superior to Hb or oxygen saturation. The risk for death after CLAD increased by 14% per reduction of OxyHem by 1 g/dL, and values below 11 g/dL corresponded to an 80% increase in mortality risk. CONCLUSION: Thus, OxyHem was identified as an independent predictor of mortality after CLAD onset. Whether it is useful in supporting therapeutic decisions and potentially home monitoring in the surveillance of lung transplant recipients has to be studied further.

Early Use of Methylene Blue in Vasoplegic Syndrome: A 10-Year Propensity Score-Matched Cohort Study.

BACKGROUND: Vasoplegic syndrome is associated with increased morbidity and mortality in patients undergoing cardiac surgery. This retrospective, single-center study aimed to evaluate the effect of early use of methylene blue (MB) on hemodynamics after an intraoperative diagnosis of vasoplegic syndrome (VS). METHODS: Over a 10-year period, all patients diagnosed with intraoperative VS (hypotension despite treatment with norepinephrine ≥0.3 µg/kg/min and vasopressin ≥1 IE/h) while undergoing heart surgery and cardiopulmonary bypass were identified, and their data were examined. The intervention group received MB (2 mg/kg intravenous) within 15 min after the diagnosis of vasoplegia, while the control group received standard therapy. The two groups were matched using propensity scores. RESULTS: Of the 1022 patients identified with VS, 221 received MB intraoperatively, and among them, 60 patients received MB within 15 min after the diagnosis of VS. After early MB application, mean arterial pressure was significantly higher, and vasopressor support was significantly lower within the first hour (p = 0.015) after the diagnosis of vasoplegia, resulting in a lower cumulative amount of norepinephrine (p = 0.018) and vasopressin (p = 0.003). The intraoperative need of fresh frozen plasma in the intervention group was lower compared to the control group (p = 0.015). Additionally, the intervention group had higher creatinine values in the first three postoperative days (p = 0.036) without changes in dialysis incidence. The 90-day survival did not differ significantly (p = 0.270). CONCLUSION: Our results indicate the additive effects of MB use during VS compared to standard vasopressor therapy only. Early MB administration for VS may significantly improve the patients' hemodynamics with minor side effects.

Impairment of Cognitive Function in Different Domains Early After Lung Transplantation.

In this prospective observational pilot study patients with the diagnosis of end-stage lung disease and listed for lung transplantation underwent a cognitive function test battery before and after lung transplantation to investigate postoperative cognitive function in three domains (visual and verbal memory, executive functioning, concentration/speed of processing). Additionally we investigated intraoperative risk factors for postoperative cognitive dysfunction. In total, 24 patients were included in this pilot study. The incidence of postoperative cognitive dysfunction was 58.3%. In the cognitive dysfunction group, the domains executive functioning and concentration/attention were significantly impaired whereas memory was not affected. Patients with cognitive impairment had a significantly longer ICU stay. The strongest independent risk factor for the development of cognitive dysfunction was operation time. No influence of cerebral oxygen desaturations on cognitive dysfunction was found. This might have important implications for early psychological rehabilitation strategies in this high-risk patient collective.

T-Cell Response in a Cardiac Xenotransplant Model.

OBJECTIVES: Despite the advances in preclinical cardiac xenotransplantation, the immune reactions caused by species differences are not fully understood. Hyperacute rejection can now be avoided using genetically engineered donor organs, but cellmediated rejection by the adaptive immune response has not been addressed successfully. Here we investigated the initial human pan-T-cell reaction using a pig-human blood working heart model. MATERIALS AND METHODS: Porcine wild-type hearts (n = 7) were perfused with human blood in a biventricular working heart system for 3 hours. As control, blood from the same human donors was circulated without a pig heart. Pan-T cells were selectively extracted from blood taken before and at the end of the perfusion cycle. The relative mRNA expression of selected target genes (real-time quantitative polymerase chain reaction) and the expression of microRNAs were determined. RESULTS: After xenogeneic organ perfusion, there was a moderate upregulation of several CD4+ marker cytokines (interleukin 2, interleukin 4, interferon γ) compared with control. We found a distinct increase in the mRNA expression of granzyme B and perforin, key markers of cytotoxic T cells. No differences in the marker genes of regulatory T cells were evident. Levels of the anti-inflammatory microRNAs miR-16 and miR-93 were significantly higher in the xenoperfused group than in the control group. CONCLUSIONS: This study demonstrated that contact of human blood with pig endothelium activates cytotoxic T cells within the first few hours, indicating acute rejection processes. This is accompanied by upregulation of anti-inflammatory microRNAs, which may represent compensatory anti-inflammatory mechanisms.

Progressive stretch enhances growth and maturation of 3D stem-cell-derived myocardium.

Bio-engineered myocardium has great potential to substitute damaged myocardium and for studies of myocardial physiology and disease, but structural and functional immaturity still implies limitations. Current protocols of engineered heart tissue (EHT) generation fall short of simulating the conditions of postnatal myocardial growth, which are characterized by tissue expansion and increased mechanical load. To investigate whether these two parameters can improve EHT maturation, we developed a new approach for the generation of cardiac tissues based on biomimetic stimulation under application of continuously increasing stretch. Methods: EHTs were generated by assembling cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CM) at high cell density in a low collagen hydrogel. Maturation and growth of the EHTs were induced in a custom-made biomimetic tissue culture system that provided continuous electrical stimulation and medium agitation along with progressive stretch at four different increments. Tissues were characterized after a three week conditioning period. Results: The highest rate of stretch (S3 = 0.32 mm/day) increased force development by 5.1-fold compared to tissue with a fixed length, reaching contractility of 11.28 mN/mm². Importantly, intensely stretched EHTs developed physiological length-dependencies of active and passive forces (systolic/diastolic ratio = 9.47 ± 0.84), and a positive force-frequency relationship (1.25-fold contractility at 180 min-1). Functional markers of stretch-dependent maturation included enhanced and more rapid Ca2+ transients, higher amplitude and upstroke velocity of action potentials, and pronounced adrenergic responses. Stretch conditioned hiPSC-CMs displayed structural improvements in cellular volume, linear alignment, and sarcomere length (2.19 ± 0.1 µm), and an overall upregulation of genes that are specifically expressed in adult cardiomyocytes. Conclusions: With the intention to simulate postnatal heart development, we have established techniques of tissue assembly and biomimetic culture that avoid tissue shrinkage and yield muscle fibers with contractility and compliance approaching the properties of adult myocardium. This study demonstrates that cultivation under progressive stretch is a feasible way to induce growth and maturation of stem cell-derived myocardium. The novel tissue-engineering approach fulfills important requirements of disease modelling and therapeutic tissue replacement.

The Degree of t-System Remodeling Predicts Negative Force-Frequency Relationship and Prolonged Relaxation Time in Failing Human Myocardium.

The normally positive cardiac force-frequency relationship (FFR) becomes flat or negative in chronic heart failure (HF). Here we explored if remodeling of the cardiomyocyte transverse tubular system (t-system) is associated with alterations in FFR and contractile kinetics in failing human myocardium. Left-ventricular myocardial slices from 13 failing human hearts were mounted into a biomimetic culture setup. Maximum twitch force (F), 90% contraction duration (CD90), time to peak force (TTP) and time to relaxation (TTR) were determined at 37°C and 0.2-2 Hz pacing frequency. F1 Hz/F0.5 Hz and F2 Hz/F0.5 Hz served as measures of FFR, intracellular cardiomyocyte t-tubule distance (ΔTT) as measure of t-system remodeling. Protein levels of SERCA2, NCX1, and PLB were quantified by immunoblotting. F1 Hz/F0.5 Hz (R 2 = 0.82) and F2 Hz/F0.5 Hz (R 2 = 0.5) correlated negatively with ΔTT, i.e., samples with severe t-system loss exhibited a negative FFR and reduced myocardial wall tension at high pacing rates. PLB levels also predicted F1 Hz/F0.5 Hz, but to a lesser degree (R 2 = 0.49), whereas NCX1 was not correlated (R 2 = 0.02). CD90 correlated positively with ΔTT (R 2 = 0.39) and negatively with SERCA2/PLB (R 2 = 0.42), indicating that both the t-system and SERCA activity are important for contraction kinetics. Surprisingly, ΔTT was not associated with TTP (R 2 = 0) but rather with TTR (R 2 = 0.5). This became even more pronounced when interaction with NCX1 expression was added to the model (R 2 = 0.79), suggesting that t-system loss impairs myocardial relaxation especially when NCX1 expression is low. The degree of t-system remodeling predicts FFR inversion and contraction slowing in failing human myocardium. Moreover, together with NCX, the t-system may be important for myocardial relaxation.

Myeloid-Derived Suppressor Cells Mediate Immunosuppression After Cardiopulmonary Bypass.

OBJECTIVES: Cardiopulmonary bypass is associated with severe immune dysfunctions. Particularly, a cardiopulmonary bypass-related long-lasting immunosuppressive state predisposes patients to a higher risk of postoperative complications, such as persistent bacterial infections. This study was conducted to elucidate mechanisms of post-cardiopulmonary bypass immunosuppression. DESIGN: In vitro studies with human peripheral blood mononuclear cells. SETTING: Cardiosurgical ICU, University Research Laboratory. PATIENTS: Seventy-one patients undergoing cardiac surgery with cardiopulmonary bypass (enrolled May 2017 to August 2018). INTERVENTIONS: Peripheral blood mononuclear cells before and after cardiopulmonary bypass were analyzed for the expression of immunomodulatory cell markers by real-time quantitative reverse transcription polymerase chain reaction. T cell effector functions were determined by enzyme-linked immunosorbent assay, carboxyfluorescein succinimidyl ester staining, and cytotoxicity assays. Expression of cell surface markers was assessed by flow cytometry. CD15 cells were depleted by microbead separation. Serum arginine was measured by mass spectrometry. Patient peripheral blood mononuclear cells were incubated in different arginine concentrations, and T cell functions were tested. MEASUREMENTS AND MAIN RESULTS: After cardiopulmonary bypass, peripheral blood mononuclear cells exhibited significantly reduced levels of costimulatory receptors (inducible T-cell costimulator, interleukin 7 receptor), whereas inhibitory receptors (programmed cell death protein 1 and programmed cell death 1 ligand 1) were induced. T cell effector functions (interferon γ secretion, proliferation, and CD8-specific cell lysis) were markedly repressed. In 66 of 71 patients, a not yet described cell population was found, which could be characterized as myeloid-derived suppressor cells. Myeloid-derived suppressor cells are known to impair immune cell functions by expression of the arginine-degrading enzyme arginase-1. Accordingly, we found dramatically increased arginase-1 levels in post-cardiopulmonary bypass peripheral blood mononuclear cells, whereas serum arginine levels were significantly reduced. Depletion of myeloid-derived suppressor cells from post-cardiopulmonary bypass peripheral blood mononuclear cells remarkably improved T cell effector function in vitro. Additionally, in vitro supplementation of arginine enhanced T cell immunocompetence. CONCLUSIONS: Cardiopulmonary bypass strongly impairs the adaptive immune system by triggering the accumulation of myeloid-derived suppressor cells. These myeloid-derived suppressor cells induce an immunosuppressive T cell phenotype by increasing serum arginine breakdown. Supplementation with L-arginine may be an effective measure to counteract the onset of immunoparalysis in the setting of cardiopulmonary bypass.

Long-term functional and structural preservation of precision-cut human myocardium under continuous electromechanical stimulation in vitro.

In vitro models incorporating the complexity and function of adult human tissues are highly desired for translational research. Whilst vital slices of human myocardium approach these demands, their rapid degeneration in tissue culture precludes long-term experimentation. Here, we report preservation of structure and performance of human myocardium under conditions of physiological preload, compliance, and continuous excitation. In biomimetic culture, tissue slices prepared from explanted failing human hearts attain a stable state of contractility that can be monitored for up to 4 months or 2000000 beats in vitro. Cultured myocardium undergoes particular alterations in biomechanics, structure, and mRNA expression. The suitability of the model for drug safety evaluation is exemplified by repeated assessment of refractory period that permits sensitive analysis of repolarization impairment induced by the multimodal hERG-inhibitor pentamidine. Biomimetic tissue culture will provide new opportunities to study drug targets, gene functions, and cellular plasticity in adult human myocardium.

Publisher Correction: Long-term functional and structural preservation of precision-cut human myocardium under continuous electromechanical stimulation in vitro.

The original version of this Article incorrectly acknowledged Elisabeth Reiser and Rene Schramm as a corresponding author. This has now been corrected in both the PDF and HTML versions of the Article.

Intraoperative Anesthetic Management of Lung Transplantation: Center-Specific Practices and Geographic and Centers Size Differences.

OBJECTIVE: Although increasing evidence in lung transplantation (LTx) suggests that intraoperative management could influence outcomes, there are no guidelines available regarding intraoperative management of LTx. The overall goal of the study was to assess geographic and center volume-specific clinical practices in perioperative management. DESIGN: Prospective data analysis. SETTING: Online survey from a single-center university hospital. PARTICIPANTS: European and non-European LTx centers. INTERVENTIONS: An online survey was sent to 176 centers currently performing LTx procedures. It covered organizational data, general anesthesia considerations, fluid therapy and coagulation, antioxidant and anti-inflammatory therapies, and ventilation strategies. MEASUREMENTS AND MAIN RESULTS: The response rates were 57.5% (n = 42) from European and 32% (n = 33) from non-European countries. Significant differences between European and non-European countries were use of volatile hypnotics (p = 0.016), use of sufentanil (p < 0.001), inotropic agents (p = 0.001) and colloid infusion (p < 0.001), use of calibrated pulse contour analysis (p = 0.004), use of intraoperative traditional laboratory-based coagulation tests (p = 0.001) and platelet function analysis (p = 0.005), and use of higher peak inspiratory pressure (p = 0.009). Center volume-specific differences were use of fentanyl (p = 0.03) and the use of higher peak inspiratory pressure (p = 0.005) for ventilation. Induction of anesthesia and use of advanced hemodynamic monitoring, therapy for pulmonary hypertension, antioxidant and anti-inflammatory therapies, and ventilation strategies were not different among the centers. CONCLUSIONS: This survey demonstrated for the first time statistically significant differences among European and non-European centers and among low- versus high-volume centers regarding intraoperative management during LTx. These observations will be of some guidance for the LTx community and may trigger more extensive studies.

Predicting the Necessity for Extracorporeal Circulation During Lung Transplantation: A Feasibility Study.

OBJECTIVE: The factors leading to the implementation of unplanned extracorporeal circulation during lung transplantation are poorly defined. Consequently, the authors aimed to identify patients at risk for unplanned extracorporeal circulation during lung transplantation. DESIGN: Retrospective data analysis. SETTING: Single-center university hospital. PARTICIPANTS: A development data set of 170 consecutive patients and an independent validation cohort of 52 patients undergoing lung transplantation. INTERVENTIONS: The authors investigated a cohort of 170 consecutive patients undergoing single or sequential bilateral lung transplantation without a priori indication for extracorporeal circulation and evaluated the predictive capability of distinct preoperative and intraoperative variables by using automated model building techniques at three clinically relevant time points (preoperatively, after endotracheal intubation, and after establishing single-lung ventilation). MEASUREMENTS AND MAIN RESULTS: Preoperative mean pulmonary arterial pressure was the strongest predictor for unplanned extracorporeal circulation. A logistic regression model based on preoperative mean pulmonary arterial pressure and lung allocation score achieved an area under the receiver operating characteristic curve of 0.85. Consequently, the authors developed a novel 3-point scoring system based on preoperative mean pulmonary arterial pressure and lung allocation score, which identified patients at risk for unplanned extracorporeal circulation and validated this score in an independent cohort of 52 patients undergoing lung transplantation. CONCLUSIONS: The authors showed that patients at risk for unplanned extracorporeal circulation during lung transplantation could be identified by their novel 3-point score.

Comparison of an advanced minimally invasive cardiac output monitoring with a continuous invasive cardiac output monitoring during lung transplantation.

The aim of this study was to compare a continuous non-calibrated left heart cardiac index (CI) measurement by arterial waveform analysis (FloTrac(®)/Vigileo(®)) with a continuous calibrated right heart CI measurement by pulmonary artery thermodilution (CCOmbo-PAC(®)/Vigilance II(®)) for hemodynamic monitoring during lung transplantation. CI was measured simultaneously by both techniques in 13 consecutive lung transplants (n = 4 single-lung transplants, n = 9 sequential double-lung transplants) at distinct time points perioperatively. Linear regression analysis and Bland-Altman analysis with percentage error calculation were used for statistical comparison of CI measurements by both techniques. In this study the FloTrac(®) system underestimated the CI in comparison with the continuous pulmonary arterial thermodilution (p < 0.000). For all measurement pairs we calculated a bias of -0.55 l/min/m(2) with limits of agreement between -2.31 and 1.21 l/min/m(2) and a percentage error of 55 %. The overall correlations before clamping a branch oft the pulmonary artery (percentage error 41 %) and during the clamping periods of a branch oft the pulmonary artery (percentage error 66 %) failed to reached the required percentage error of less than 30 %. We found good agreement of both CI measurements techniques only during the measurement point "15 min after starting the second one-lung ventilation period" (percentage error 30 %). No agreement was found during all other measurement points. This pilot study shows for the first time that the CI of the FloTrac(®) system is not comparable with the continuous pulmonary-artery thermodilution during lung transplantation including the time periods without clamping a branch of the pulmonary artery. Arterial waveform and continuous pulmonary artery thermodilution are, therefore, not interchangeable during these complex operations.