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Elevated pulmonary vascular resistance (PVR) is broadly accepted as an imminent risk factor for mortality after heart transplantation (HTx). However, no current HTx recipient risk score includes PVR or other hemodynamic parameters. This study examined the utility of various hemodynamic parameters for risk stratification in a contemporary HTx population.Patients from seven German HTx centers undergoing HTx between 2011 and 2015 were included retrospectively. Established risk factors and complete hemodynamic datasets before HTx were analyzed. Outcome measures were overall all-cause mortality, 12-month mortality, and right heart failure (RHF) after HTx.The final analysis included 333 patients (28% female) with a median age of 54 (IQR 46-60) years. The median mean pulmonary artery pressure was 30 (IQR 23-38) mm Hg, transpulmonary gradient 8 (IQR 5-10) mm Hg, and PVR 2.1 (IQR 1.5-2.9) Wood units. Overall mortality was 35.7%, 12-month mortality was 23.7%, and the incidence of early RHF was 22.8%, which was significantly associated with overall mortality (log-rank HR 4.11, 95% CI 2.47-6.84; log-rank p.0001). Pulmonary arterial elastance (Ea) was associated with overall mortality (HR 1.74, 95% CI 1.25-2.30; p.001) independent of other non-hemodynamic risk factors. Ea values below a calculated cutoff represented a significantly reduced mortality risk (HR 0.38, 95% CI 0.19-0.76; p.0001). PVR with the established cutoff of 3.0 WU was not significant. Ea was also significantly associated with 12-month mortality and RHF.Ea showed a strong impact on post-transplant mortality and RHF and should become part of the routine hemodynamic evaluation in HTx candidates.

Zusammenfassung Hintergrund Telemonitoring dient der Überwachung von implantierbaren Kardioverter-Defibrillatoren (ICD). Trotz der wissenschaftlich nachgewiesenen Effektivität und Sicherheit der telemetrischen Versorgung zeigen Studien, dass das Angebot nicht bei allen Patienten mit der Nutzung und Akzeptanz des Telemonitorings einhergeht. Fragestellung Ziel dieses Forschungsvorhabens ist die Untersuchung der Einstellungen von ICD-Patienten zum Telemonitoring. Dabei ist von Interesse, welche Aspekte Einfluss auf die Haltung und Entscheidungsfindung nehmen. Methode Die Datenerhebung erfolgte anhand teilstrukturierter leitfadengestützter Einzelinterviews. Es wurden insgesamt 14 Patienten mit subkutanem ICD und sowohl primär als auch sekundärprophylaktischer Indikation rekrutiert. Die Datenauswertung erfolgte nach inhaltlich strukturierender qualitativer Vorgehensweise. Ergebnis Die Studie hat gezeigt, dass die Patienten mit Telemonitoring einen hohen Nutzen sehen, bei geringem Bedenken hinsichtlich der digitalen Technik. Bei Patienten ohne Telemonitoring verhält es sich umgekehrt. Die medizinischen Vorerfahrungen der Patienten haben einen wesentlichen Einfluss auf die Akzeptanz des Telemonitorings. Die technische Umsetzung und die praktische Handhabung des Telemonitorings wurden von Patienten aller Altersgruppen als einfach und unkompliziert angesehen. Diskussion Die Ergebnisse lassen darauf schließen, dass die primär- und sekundärprophylaktische Indikation für eine ICD-Implantation einen Einfluss auf die Einstellung zum Telemonitoring und somit auf dessen Akzeptanz haben. Die Ergebnisse geben Anlass zu weiterer qualitativer Forschung im Hinblick auf die Nutzerakzeptanz zum Telemonitoring anderer ICD-Systeme.

Aims Atrial fibrillation (AF) after heart transplantation (HTX) is associated with worse clinical outcomes. The current study aimed to analyse the association between AF before HTX and AF within 30 days after HTX. Methods and results This study included 639 adults who received HTX at Heidelberg Heart Center. Patients were subdivided into four groups depending on the status of AF before and after HTX. Analyses comprised recipient and donor data, medication, echocardiographic features, permanent pacemaker implantation, stroke, and mortality after HTX. Three hundred thirty‐two patients (52.0%) had neither AF before nor after HTX, 15 patients (2.3%) had no AF before HTX but showed AF after HTX, 219 patients (34.3%) showed AF before HTX but had no AF after HTX, and 73 patients (11.4%) had AF before and after HTX. Patients with AF before and after HTX had a higher 1 year post‐transplant mortality (39.7%) than patients without AF before or after HTX (18.1%, P

Aims Immunocompromised patients have been excluded from studies of SARS-CoV-2 messenger RNA vaccines. The immune response to vaccines against other infectious agents has been shown to be blunted in such patients. We aimed to analyse the humoral and cellular response to prime-boost vaccination with the BNT162b2 vaccine (Pfizer-BioNTech) in cardiothoracic transplant recipients. Methods and results A total of 50 transplant patients [1–3 years post heart (42), lung (7), or heart–lung (1) transplant, mean age 55 ± 10 years] and a control group of 50 healthy staff members were included. Blood samples were analysed 21 days after the prime and the boosting dose, respectively, to quantify anti-SARS-CoV-2 spike protein (S) immunoglobulin titres (tested by Abbott, Euroimmun and RocheElecsys Immunoassays, each) and the functional inhibitory capacity of neutralizing antibodies (Genscript). To test for a specific T-cell response, heparinized whole blood was stimulated with SARS-CoV-2 specific peptides, covering domains of the viral spike, nucleocapsid and membrane protein, and the interferon-γ release was measured (QuantiFERON Monitor ELISA, Qiagen). The vast majority of transplant patients (90%) showed neither a detectable humoral nor a T-cell response three weeks after the completed two-dose BNT162b2 vaccination; these results are in sharp contrast to the robust immunogenicity seen in the control group: 98% exhibited seroconversion after the prime dose already, with a further significant increase of IgG titres after the booster dose (average > tenfold increase), a more than 90% inhibition capability of neutralizing antibodies as well as evidence of a T-cell responsiveness. Conclusions The findings of poor immune responses to a two-dose BNT162b2 vaccination in cardiothoracic transplant patients have a significant impact for organ transplant recipients specifically and possibly for immunocompromised patients in general. It urges for a review of future vaccine strategies in these patients.

Aims Right bundle branch block (RBBB) after heart transplantation (HTX) is a common finding, but its impact on post‐transplant survival remains uncertain. This study investigated the post‐transplant outcomes of patients with complete RBBB (cRBBB) ≤ 30 days after HTX. Methods This registry study analysed 639 patients receiving HTX at Heidelberg Heart Center between 1989 and 2019. Patients were stratified by diagnosis of cRBBB ≤ 30 days after HTX. Analysis included recipient and donor data, medication, echocardiographic features, graft rejections, atrial fibrillation, heart rates, permanent pacemaker implantation and mortality after HTX including causes of death. Results One hundred thirty‐nine patients showed cRBBB ≤ 30 days after HTX (21.8%), 20 patients with pre‐existing cRBBB in the donor heart (3.2%) and 119 patients with newly acquired cRBBB (18.6%). Patients with newly acquired cRBBB had a worse 1‐year post‐transplant survival (36.1%, P

Background We report the results of a prospective study on the immunogenicity of a 3rd dose of BNT162b2 in thoracic organ recipients with no or minimal response following a two-dose BNT162b2 vaccination scheme. Methods A total of 243 transplant recipients received a homologue 3rd dose. Anti-SARS-CoV2-immunoglobulins (IgGs) were monitored immediately before (T1), 4 weeks (T2) as well as 2 and 4 months after the 3rd dose. Neutralizing antibody capacity (NAC) was determined at T2. To reveal predictors for detectable humoral response, patients were divided into a positive response group (n = 129) based on the combined criteria of IgGs and NAC above the defined cut-offs at T2—and a group with negative response (n = 114), with both, IgGs and NAC beyond the cut-offs. Results The 3rd dose induced a positive humoral response in 53% of patients at T2, 47% were still non-responsive. Sero-positivity was significantly stronger in patients who presented with weak, but detectable IgGs already prior to the booster (T1), when compared to those with no detectable response at T1. Multivariable analysis identified age > 55 years, a period since transplantation Conclusions Our data indicate that a lack of immunogenicity is linked to the type and extent of maintenance immunosuppression. The necessity of the cumulative immunosuppressive regimen might individually be questioned and possibly be reduced to enhance the chance of an immune response following an additional booster dose.

BACKGROUND Mesenchymal stem cells (MSC) modified by gene transfer to express cardiac pacemaker channels such as HCN2 or HCN4 were shown to elicit pacemaker function after intracardiac transplantation in experimental animal models. Human MSC derived from adipose tissue (haMSC) differentiate into cells with pacemaker properties in vitro, but little is known about their behavior after intracardiac transplantation. AIM To investigate whether haMSC elicit biological pacemaker function in vivo after transplantation into pig hearts. METHODS haMSC under native conditions (nhaMSC) or after preconditioning by medium differentiation (dhaMSC) (n = 6 pigs each, 5 × 106 cells per animal) were injected into the porcine left ventricular free wall. Animals receiving PBS injection served as controls (n = 6). Four weeks later, total atrioventricular (AV)-block was induced by radiofrequency catheter ablation, and electronic pacemaker devices were implanted for backup stimulation and heart rate monitoring. Ventricular rate and rhythm of pigs were evaluated during a follow-up of 15 d post ablation by 12-lead-ECG with heart rate assessment, 24-h continuous rate monitoring recorded by electronic pacemaker, assessment of escape recovery time, and pharmacological challenge to address catecholaminergic rate response. Finally, hearts were analyzed by histological and immunohistochemical investigations. RESULTS In vivo transplantation of dhaMSC into the left ventricular free wall of pigs elicited spontaneous and regular rhythms that were pace-mapped to ventricular injection sites (mean heart rate 72.2 ± 3.6 bpm; n = 6) after experimental total AV block. Ventricular rhythms were stably detected over a 15-d period and were sensitive to catecholaminergic stimulation (mean maximum heart rate 131.0 ± 6.2 bpm; n = 6; P < 0.001). Pigs, which received nhaMSC or PBS presented significantly lower ventricular rates (mean heart rates 47.2 ± 2.5 bpm and 37.4 ± 3.2 bpm, respectively; n = 6 each; P < 0.001) and exhibited little sensitivity towards catecholaminergic stimulation (mean maximum heart rates 76.4 ± 3.1 bpm and 60.5 ± 3.1 bpm, respectively; n = 6 each; P < 0.05). Histological and immunohistochemical evaluation of hearts treated with dhaMSC revealed local clusters of transplanted cells at the injection sites that lacked macrophage or lymphocyte infiltrations or tumor formation. Intense fluorescence signals at these sites indicated membrane expression of HCN4 and other pacemaker-specific proteins involved in cardiac automaticity and impulse propagation. CONCLUSION dhaMSC transplanted into pig left ventricles sustainably induced rate-responsive ventricular pacemaker activity after in vivo engraftment for four weeks. The data suggest that preconditioned MSC may further differentiate along a pacemaker-related lineage after myocardial integration and may establish superior pacemaker properties in vivo.

Aims Amiodarone and digitalis are frequently used drugs in patients with heart failure. Both have separately been linked to reduced post‐transplant survival, but their combined impact on mortality after HTX remains uncertain. This study investigated the effects of combined amiodarone and digitalis use before HTX on post‐transplant outcomes. Methods and results This registry study analysed 600 patients receiving HTX at Heidelberg Heart Center between 1989 and 2016. Patients were stratified by amiodarone and digitalis use before HTX. Analysis included patient characteristics, medication, echocardiographic features, heart rates, permanent pacemaker implantation, atrial fibrillation, and post‐transplant survival including causes of death. One hundred eighteen patients received amiodarone before HTX (19.7%), hereof 67 patients with digitalis (56.8%) and 51 patients without digitalis before HTX (43.2%). Patients with and without amiodarone before HTX showed a similar 1 year post‐transplant survival (72.0% vs. 78.4%, P = 0.11), but patients with combined amiodarone and digitalis before HTX had a worse 1 year post‐transplant survival (64.2%, P = 0.01), along with a higher percentage of death due to transplant failure (P = 0.03). Echocardiographic analysis of these patients showed a higher percentage of an enlarged right ventricle (P = 0.02), left atrium (P = 0.02), left ventricle (P = 0.03), and a higher rate of reduced left ventricular ejection fraction (P = 0.03). Multivariate analysis indicated combined amiodarone and digitalis use before HTX as a significant risk factor for 1 year mortality after HTX (hazard ratio: 1.69; 95% confidence interval: 1.02–2.77; P = 0.04). Conclusions Combined pre‐transplant amiodarone and digitalis therapy is associated with increased post‐transplant mortality.

Aims Severely elevated pre‐transplant pulmonary vascular resistance (PVR) has been linked to adverse effects after heart transplantation (HTX). The impact of a moderately increased PVR before HTX on post‐transplant outcomes remains uncertain. The aim of this study was to investigate the effects of an elevated pre‐transplant PVR ≥ 300 dyn·s·cm−5 (≥3.75 Wood units) on outcomes after HTX. Methods and results This observational retrospective single‐centre study included 561 patients receiving HTX at Heidelberg Heart Center between 1989 and 2015. Patients were stratified by degree of pre‐transplant PVR. Analyses covered demographics, post‐transplant medication, mortality and causes of death after HTX, early post‐transplant atrial fibrillation (AF), and length of the initial hospital stay after HTX. Ninety‐four patients (16.8%) had a PVR ≥ 300 dyn·s·cm−5 (≥3.75 Wood units). These patients had a higher rate of early post‐transplant AF [20.2 vs. 10.7%, difference: 9.5%, 95% confidence interval (CI): 0.9–18.1%, P = 0.01] and an increased 30 day post‐transplant mortality (25.5 vs. 6.4%, hazard ratio: 4.4, 95% CI: 2.6–7.6, P < 0.01), along with a higher percentage of death due to transplant failure (21.2 vs. 4.1%, difference: 17.1%, 95% CI: 8.7–25.5%, P < 0.01). Multivariate analysis revealed a PVR ≥ 300 dyn·s·cm−5 (≥3.75 Wood units) as a significant risk factor for increased 30 day mortality after HTX (hazard ratio: 4.4, 95% CI: 2.5–7.6, P < 0.01). Kaplan–Meier estimator showed a lower 2 year survival after HTX (P < 0.01) in patients with a PVR ≥ 300 dyn·s·cm−5 (≥3.75 Wood units). Conclusions Elevated pre‐transplant PVR ≥ 300 dyn·s·cm−5 (≥3.75 Wood units) is associated with early post‐transplant AF and increased mortality after HTX.

The authors have requested that this preprint be removed from Research Square.

BACKGROUND Giving patients access to their medical records can improve health literacy, adherence to therapy, patients’ health-related self-care, doctor-patient communication, and quality of care. The application (app) phellow (“personal health fellow”) was developed to provide patients with mobile access to selected content of their medical records (i.e. physician letters, drug trough levels). It was tested at the heart transplantation (HTx) outpatient clinic at Heidelberg University Hospital among volunteer patients after heart transplantation from late 2018 onward. OBJECTIVE The aims of this study were (1) to assess whether the phellow app can be effectively used by all participating parties (usability) and (2) to determine if the app is feasible to be further implemented in routine care (feasibility). METHODS Usability was quantitatively measured through the System Usability Scale (SUS) among patients who actively used phellow. In addition, usability and feasibility were qualitatively measured through semi-structured guide-based interviews with patients (users, non-users) and health care providers (medical staff, physicians) from the HTx outpatient clinic. Quantitative data were analyzed descriptively and through correlation analyses. Qualitative data were pseudonymized, audiotaped, and transcribed verbatim. Themes were identified through thematic analysis. RESULTS The usability rating measured with the SUS questionnaire (n=31) was 79,9 (SD 14,1) which indicates a high usability. No statistically significant correlation was found between SUS scores and patients’ age, gender, or frequency or duration of phellow use. A more in-depth view on usability and feasibility was obtained from interviews with 16 patients (5 non-users, 11 users) and 7 health care providers (HCPs; 4 medical staff members, 3 physicians) (n=23). App appreciation, interest, and willingness-to-use were high. Tasks fit with clinic workflow and were perceived as clear. An improved technical support infrastructure, clearly defined responsibilities, and app-specific trainings were requested for further implementation. Usability problems such as incompleteness of record, incomprehensible presentation of content, technical issues (e.g. sudden app crashes), and complex registration procedures were reported. Participants recommended usability improvements (e.g. chronically plausible presentation of record content, simplified registration and log-in) and suggested new functionalities (e.g. access to full record, communication module, appointments, medication refill requests). CONCLUSIONS Despite some usability issues, usability of the phellow app was considered high. To be feasible for an implementation in routine care, usability problems should be solved. Accompanying research is crucial to monitor usability improvements and to assess effects of app use on patients and clinic workflow.

Atrial fibrillation (AF) is associated with electrical remodeling, leading to cellular electrophysiological dysfunction and arrhythmia perpetuation. Emerging evidence suggests a key role for epigenetic mechanisms in the regulation of ion channel expression. Histone deacetylases (HDACs) control gene expression through deacetylation of histone proteins. We hypothesized that class I HDACs in complex with neuron-restrictive silencer factor (NRSF) determine atrial K+ channel expression. AF was characterized by reduced atrial HDAC2 mRNA levels and upregulation of NRSF in humans and in a pig model, with regional differences between right and left atrium. In vitro studies revealed inverse regulation of Hdac2 and Nrsf in HL-1 atrial myocytes. A direct association of HDAC2 with active regulatory elements of cardiac K+ channels was revealed by chromatin immunoprecipitation. Specific knock-down of Hdac2 and Nrsf induced alterations of K+ channel expression. Hdac2 knock-down resulted in prolongation of action potential duration (APD) in neonatal rat cardiomyocytes, whereas inactivation of Nrsf induced APD shortening. Potential AF-related triggers were recapitulated by experimental tachypacing and mechanical stretch, respectively, and exerted differential effects on the expression of class I HDACs and K+ channels in cardiomyocytes. In conclusion, HDAC2 and NRSF contribute to AF-associated remodeling of APD and K+ channel expression in cardiomyocytes via direct interaction with regulatory chromatin regions. Specific modulation of these factors may provide a starting point for the development of more individualized treatment options for atrial fibrillation.

Atrial fibrillation (AF) is associated with electrical remodeling, leading to cellular electrophysiological dysfunction and arrhythmia perpetuation. Emerging evidence suggests a key role for epigenetic mechanisms in the regulation of ion channel expression. Histone deacetylases (HDACs) control gene expression through deacetylation of histone proteins. We hypothesized that class I HDACs in complex with neuron-restrictive silencer factor (NRSF) determine atrial K

Engraftment and functional integration of stem cells or stem cell-derived cells within cardiac tissue is an important prerequisite for cell replacement therapy aiming at the treatment of heart disease. Recently, a novel intravenous approach for application of mesenchymal stromal cells (MSCs) to cardiac sites has been established using radiofrequency catheter ablation (RFCA)-guided targeting, bypassing the need for open chest surgery or direct myocardial cell injection. However, little is known about the quantitative efficacy and longevity of this strategy. We performed selective power-controlled RFCA with eight ablation pulses (30 W, 60 s each) to induce heat-mediated lesions at the right atrial appendices (RAAs) of pigs. Different concentrations of human bone marrow-derived MSCs (105 to 1.6 × 106 cells/kg bodyweight) labeled with superparamagnetic iron oxide (SPIO) particles were infused intravenously in nine pigs one d after RFCA treatment and hearts were explanted 8 d later to quantify the number of engrafted cells. Prussian blue staining revealed high numbers of SPIO-labeled cells in areas surrounding the RFCA-induced lesions. Cell numbers were evaluated by quantitative real-time polymerase chain reaction using specific primers for human MSCs (hMSCs), which indicated that up to 106 hMSCs, corresponding to ∼3.9% of the systemically applied human cells, engrafted within the RAAs of RFCA-treated pigs. Of note, infused hMSCs were observed in nontargeted organs, as well, but appeared at very low concentrations. To assess long-term deposition of MSCs, RAAs of three pigs were analyzed after 6 months, which revealed few persisting hMSCs at targeted sites. RFCA-mediated targeting of MSCs provides a novel minimal invasive strategy for cardiac stem cell engraftment. Qualitative and quantitative results of our large animal experiments indicate an efficient guidance of MSCs to selected cardiac regions, although only few cells remained at targeted sites 6 mo after cell transplantation.

Background Cardiac graft denervation causes inadequate sinus tachycardia in patients after heart transplantation (HTX) which is associated with reduced survival. This study investigated the 5-year results of heart rate control with ivabradine or metoprolol succinate in patients after HTX. Methods This registry study analyzed 104 patients receiving either ivabradine (n = 50) or metoprolol succinate (n = 54) within 5 years after HTX. Analysis included patient characteristics, medication, echocardiographic features, cardiac catheterization data, cardiac biomarkers, heart rates, and post-transplant survival including causes of death. Results Demographics and post-transplant medication revealed no significant differences except for ivabradine and metoprolol succinate use. At 5-year follow-up, patients with ivabradine had a significantly lower heart rate (73.3 bpm) compared to baseline (88.6 bpm; P P P P P P P P P Conclusion Patients receiving ivabradine showed a superior heart rate reduction and a better left ventricular diastolic function along with an improved 5-year survival after HTX.

Aims Heart transplantation may represent a particular risk factor for severe coronavirus infectious disease 2019 (COVID-19) due to chronic immunosuppression and frequent comorbidities. We conducted a nation-wide survey of all heart transplant centers in Germany presenting the clinical characteristics of heart transplant recipients with COVID-19 during the first months of the pandemic in Germany. Methods and results A multicenter survey of all heart transplant centers in Germany evaluating the current status of COVID-19 among adult heart transplant recipients was performed. A total of 21 heart transplant patients with COVID-19 was reported to the transplant centers during the first months of the pandemic in Germany. Mean patient age was 58.6 ± 12.3 years and 81.0% were male. Comorbidities included arterial hypertension (71.4%), dyslipidemia (71.4%), diabetes mellitus (33.3%), chronic kidney failure requiring dialysis (28.6%) and chronic-obstructive lung disease/asthma (19.0%). Most patients received an immunosuppressive drug regimen consisting of a calcineurin inhibitor (71.4%), mycophenolate mofetil (85.7%) and steroids (71.4%). Eight of 21 patients (38.1%) displayed a severe course needing invasive mechanical ventilation. Those patients showed a high mortality (87.5%) which was associated with right ventricular dysfunction (62.5% vs. 7.7%; p = 0.014), arrhythmias (50.0% vs. none; p = 0.012), and thromboembolic events (50.0% vs. none; p = 0.012). Elevated high-sensitivity cardiac troponin T- and N-terminal prohormone of brain natriuretic peptide were significantly associated with the severe form of COVID-19 (p = 0.017 and p Conclusion Severe course of COVID-19 was frequent in heart transplanted patients. High mortality was associated with right ventricular dysfunction, arrhythmias, thromboembolic events, and markedly elevated cardiac biomarkers.

Patients after heart transplantation (HTX) present with sinus tachycardia due to graft denervation. As elevated heart rates negatively affect survival, the aim of this study was to analyze the effects of ivabradine vs metoprolol succinate on heart rate, left ventricular (LV) mass and survival following HTX. This observational retrospective single-center study assessed 84 patients continuously receiving either ivabradine (n = 40) or metoprolol succinate (n = 44) within 2 years after HTX. Patients with dual therapy (ivabradine and metoprolol succinate), other beta blockers, amiodarone, or digitalis were excluded. Patient characteristics, post-transplant medication, heart rates, LV mass, and survival were investigated. Analysis of patient characteristics, immunosuppressive drug regimen, and post-transplant medication showed no significant differences between groups except for ivabradine and metoprolol succinate. Baseline heart rates differed not significantly between patients treated with ivabradine [87.0 beats per minute (bpm)] and metoprolol succinate (86.2 bpm; P = 0.6395). At 2-year follow-up, patients with ivabradine (76.7 bpm) had a significantly lower heart rate compared to baseline (P

Transient outward K

Aims Cell-based biological pacemakers aim to overcome limitations and side effects of electronic pacemaker devices. We here developed and tested different approaches to achieve nodal-type differentiation using human adipose- and bone marrow-derived mesenchymal stem cells (haMSC, hbMSC). Main methods haMSC and hbMSC were differentiated using customized protocols. Quantitative RT-PCR was applied for transcriptional pacemaker-gene profiling. Protein membrane expression was analyzed by immunocytochemistry. Pacemaker current (If) was studied in haMSC with and without lentiviral HCN4-transduction using patch clamp recordings. Functional characteristics were evaluated by co-culturing with neonatal rat ventricular myocytes (NRVM). Key findings Culture media-based differentiation for two weeks generated cells with abundant transcription of ion channel genes (Cav1.2, NCX1), transcription factors (TBX3, TBX18, SHOX2) and connexins (Cx31.9 and Cx45) characteristic for cardiac pacemaker tissue, but lack adequate HCN transcription. haMSC-derived cells revealed transcript levels, which were closer related to sinoatrial nodal cells than hbMSC-derived cells. To substitute for the lack of If, we performed lentiviral HCN4-transduction of haMSC resulting in stable If. Co-culturing with NRVM demonstrated that differentiated haMSC expressing HCN4 showed earlier onset of spontaneous contractions and higher beating regularity, synchrony and rate compared to co-cultures with non-HCN4-transduced haMSC or HCN4-transduced, non-differentiated haMSC. Confocal imaging indicated increased membrane expression of cardiac gap junctional proteins in differentiated haMSC. Significance By differentiation haMSC, rather than hbMSC attain properties favorable for cardiac pacemaking. In combination with lentiviral HCN4-transduction, a cellular phenotype was generated that sustainably controls and stabilizes rate in co-culture with NRVM.

Transient outward K+ current, Ito, contributes to cardiac action potential generation and is primarily carried by Kv4.3 (KCND3) channels. Two Kv4.3 isoforms are expressed in human ventricle and show differential remodeling in heart failure (HF). Lidocaine and mexiletine may be applied in selected patients to suppress ventricular arrhythmias, without effects on sudden cardiac death or mortality. Isoform-dependent effects of antiarrhythmic drugs on Kv4.3 channels and potential implications for remodeling-based antiarrhythmic management have not been assessed to date. We sought to test the hypotheses that Kv4.3 channels are targeted by lidocaine and mexiletine, and that drug sensitivity is determined in isoform-specific manner. Expression of KCND3 isoforms was quantified using qRT-PCR in left ventricular samples of patients with HF due to either ischemic or dilated cardiomyopathies (ICM or DCM). Long (Kv4.3-L) and short (Kv4.3-S) isoforms were heterologously expressed in Xenopus laevis oocytes to study drug sensitivity and effects on biophysical characteristics activation, deactivation, inactivation, and recovery from inactivation. In the present HF patient cohort KCND3 isoform expression did not differ between ICM and DCM. In vitro, lidocaine (IC50-Kv4.3-L: 0.8 mM; IC50-Kv4.3-S: 1.2 mM) and mexiletine (IC50-Kv4.3-L: 146 μM; IC50-Kv4.3-S: 160 μM) inhibited Kv4.3 with different sensitivity. Biophysical analyses identified accelerated and enhanced inactivation combined with delayed recovery from inactivation as primary biophysical mechanisms underlying Kv4.3 current reduction. In conclusion, differential effects on Kv4.3 isoforms extend the electropharmacological profile of lidocaine and mexiletine. Patient-specific remodeling of Kv4.3 isoforms may determine individual drug responses and requires consideration during clinical application of compounds targeting Kv4.3.

Objectives Digitalis therapy (digoxin or digitoxin) in patients with heart failure is subject to an ongoing debate. Recent data suggest an increased mortality in patients receiving digitalis. This study investigated the effects of chronic digitalis therapy prior to heart transplantation (HTX) on posttransplant outcomes. Patients and methods This was a retrospective, observational, single-center study. It comprised 530 adult patients who were heart-transplanted at Heidelberg University Hospital between 1989 and 2012. Patients with digitalis prior to HTX (≥3 months) were compared to those without (no or

Background A calcineurin inhibitor (CNI)-based immunosuppression combined with mammalian target of rapamycin inhibitors (mTORs) seems to be attractive in patients after heart transplantation (HTX) in special clinical situations, for example, in patients with adverse drug effects of prior immunosuppression. Previous studies in patients after HTX detected advantageous effects regarding renal function of a tacrolimus (TAC)-based vs cyclosporine-A (CSA)-based immunosuppression (in combination with mycophenolate mofetil). However, data regarding renal function after HTX in mTOR/CNI patients remain limited. Aim Primary end point of the present study was to analyze renal function in HTX patients 1 year after switch to an mTOR/CNI-based immunosuppression. Methods Data of 80 HTX patients after change to mTOR/CNI-based immunosuppression were retrospectively analyzed. Renal function was assessed by measured serum creatinine and by estimated glomerular filtration rate (eGFR) calculated from Modification of Diet in Renal Disease equation. Results Twenty-nine patients received mTOR/CSA-based treatment and 51 patients received mTOR/TAC-based therapy. At time of switch and at 1-year follow-up, serum creatinine and eGFR did not differ significantly between both study groups (all P=not statistically significant). Analysis of variances with repeated measurements detected a similar change of renal function in both study groups. Conclusion The present study detected no significant differences between both mTOR/CNI study groups, indicating a steady state of renal function in HTX patients after switch of immunosuppressive regimen.

Rasmus Rivinius,1 Matthias Helmschrott,1 Arjang Ruhparwar,2 Christian Erbel,1 Christian A Gleissner,1 Fabrice F Darche,1 Dierk Thomas,1 Tom Bruckner,3 Hugo A Katus,1 Andreas O Doesch1 1Department of Cardiology, Angiology and Pneumology, 2Department of Cardiac Surgery, Heidelberg University Hospital, 3Institute for Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany Purpose: Early posttransplant atrial fibrillation (AF) has been associated with worse clinical outcomes after heart transplantation (HTX). The type of surgical technique may constitute a relevant risk factor for AF. Patients and methods: This retrospective single-center study included 530 adult patients. Patients were stratified by surgical technique (biatrial, bicaval, or total orthotopic HTX) and early posttransplant heart rhythm (AF or sinus rhythm). Univariate and multivariate analyses were performed to evaluate risk factors for AF. Results: A total of 161 patients received biatrial HTX (30.4%), 115 bicaval HTX (21.7%), and 254 total orthotopic HTX (47.9%). Sixty-one of 530 patients developed early posttransplant AF (11.5%). Patients with AF showed a statistically inferior 5-year survival compared to those with sinus rhythm (P

High-energy ion beams are successfully used in cancer therapy and precisely deliver high doses of ionizing radiation to small deep-seated target volumes. A similar noninvasive treatment modality for cardiac arrhythmias was tested here. This study used high-energy carbon ions for ablation of cardiac tissue in pigs. Doses of 25, 40, and 55 Gy were applied in forced-breath-hold to the atrioventricular junction, left atrial pulmonary vein junction, and freewall left ventricle of intact animals. Procedural success was tracked by (1.) in-beam positron-emission tomography (PET) imaging; (2.) intracardiac voltage mapping with visible lesion on ultrasound; (3.) lesion outcomes in pathohistolgy. High doses (40–55 Gy) caused slowing and interruption of cardiac impulse propagation. Target fibrosis was the main mediator of the ablation effect. In irradiated tissue, apoptosis was present after 3, but not 6 months. Our study shows feasibility to use high-energy ion beams for creation of cardiac lesions that chronically interrupt cardiac conduction.

A 57-year-old man presented with recurrent episodes of dizziness, weakness of legs, and presyncope. The electrocardiogram showed a sinus bradycardia and recurrent sinus pauses. Cardiac evaluation revealed a normal left ventricular ejection fraction without ischemic, structural, or valvular heart disease. Pronounced limb weakness prompted neurological consultation. Cranial magnetic resonance imaging showed a large right-sided intracranial tumor adjacent to the medial sphenoid wing. Surgical removal of the tumor was accomplished successfully after application of a transient cardiac pacemaker, while decision upon permanent pacemaker implantation was postponed. Histopathology provided evidence of a meningothelial meningioma. Postoperative assessment displayed the absence of sinus node dysfunction after tumor removal. Careful differential diagnostic assessment of patients with symptomatic bradycardias needs to rule out reversible causes before implantation of permanent devices.

In recent times, practice in cardiac surgery has shifted towards using endoscopic techniques to harvest the saphenous vein from the leg for use as a bypass graft. A paper published in the New England Journal of Medicine (NEJM) in 2009 raised concerns over increased graft occlusion rates in veins harvested endoscopically. This NEJM paper has been criticized, but has nonetheless been influential in guiding practice. We have undertaken this meta-analysis to provide evidence on the clinical outcomes of endoscopic vein harvesting (EVH), so that clinicians can make an informed judgement about whether this technique, popular as it is with patients, should still be offered. We systematically reviewed the global literature and performed a meta-analysis of clinical outcomes after endoscopic and open vein harvesting. In all outcomes, endoscopic harvesting appears to be equal, if not superior, to open harvesting. The suspicion of higher rates of vein graft occlusion was not borne out by randomized studies. When considering evidence from only randomized studies, there is no statistical difference in vein graft stenosis or occlusion between open and endoscopically harvested veins. In conclusion, EVH reduces pain and leg wound complications. At a median follow-up of 2.6 years, we found no significant difference in mortality, myocardial infarction, repeat revascularization, angina recurrence, vein graft stenosis or occlusion. Therefore, the authors support the ongoing use of endoscopic harvesting techniques.

Rasmus Rivinius,1 Matthias Helmschrott,1 Arjang Ruhparwar,2 Bastian Schmack,2 Berthold Klein,2 Christian Erbel,1 Christian A Gleissner,1 Mohammadreza Akhavanpoor,1 Lutz Frankenstein,1 Fabrice F Darche,1 Dierk Thomas,1 Philipp Ehlermann,1 Tom Bruckner,3 Hugo A Katus,1 Andreas O Doesch11Department of Cardiology, Angiology and Pneumology, 2Department of Cardiac Surgery, 3Institute for Medical Biometry and Informatics, University of Heidelberg, Heidelberg, GermanyObjective: The aim of this study was to analyze the distribution of malignancies in patients after heart transplantation (HTX) and to evaluate the risk factors including immunosuppressive therapy with regard to the development of malignancies and survival. Special emphasis was placed on the effects of a mammalian target of rapamycin (mTOR) containing immunosuppressive regimen.Methods: A total of 381 patients (age ≥18 years) receiving HTX were included in the present analysis. All patients were followed-up at the University of Heidelberg Heart Center, Heidelberg, Germany. Data were retrieved from the Heidelberg Registry for Heart Transplantation being collected between 1989 and 2014. According to center standard, all patients received induction therapy with anti-thymocyte globulin guided by T-cell monitoring since 1994. The initial immunosuppressive regimen consisting of cyclosporine A (CsA) and azathioprine (AZA) was replaced by CsA and mycophenolate mofetil (MMF) in 2001 and by tacrolimus (TAC) and MMF in 2006. Additionally, mTOR inhibitors (everolimus/sirolimus) were applied since 2003.Results: Mean recipient age at HTX was 51.2±10.5years and the mean follow-up period after HTX was 9.7±5.9years. During follow-up, 130 patients developed a neoplasm (34.1% of total). Subgroup analysis revealed 58 patients with cutaneous malignancy only (15.2%), 56 patients with noncutaneous malignancy only (14.7%), and 16 patients with both cutaneous and noncutaneous malignancy (4.2%). Statistically significant risk factors associated with an increased risk of malignancy after HTX were older age (P1 treated rejection episode (TRE) in the first year after HTX (P=0.0091). Administration of CsA (P=0.0195), AZA (P=0.0008), or steroids (P=0.0018) for >1 year after HTX was associated with increased development of malignancy, whereas administration of MMF (P