Search

Objectives: Erythropoietin (EPO) improved cardiac regeneration in experimental models of ischemic heart disease. A pilot trial found subcutaneously administered EPO to improve surrogate markers of left ventricular (LV) function in ischemic cardiomyopathy. This clinical study tests the feasibility and safety of the intramyocardial delivery route of a long-acting EPO-analogue (C.E.R.A.) in patients with ischemic cardiomyopathy. Methods: The ALSTER C.E.R.A. trial was a Phase II, open label, 1:1 randomized, single-center study testing intramyocardial injections of long-acting EPO analogue C.E.R.A. (C.E.R.A. NOGA: once 180 µg) using the NOGA XP system versus the subcutaneous application (C.E.R.A. SC: 30µg s.c./month for 6 months) in 59 symptomatic chronic heart failure (HF) patients with impaired LV function (ejection fraction (EF) £ 45%). Results: Follow-up up to three years with both clinical and imaging endpoints found intramyocardial delivery of C.E.R.A. to be feasible, safe and to possibly attenuate LV remodeling. Patients in the C.E.R.A. NOGA group showed stable parameter for LV end-diastolic diameter and volume (LVEDD and LVEDV), while C.E.R.A. SC patients had significant dilation of the LV (C.E.R.A. NOGA vs. SC, mean ± standard error of the mean: DLVEDD 0.02±0.1mm, p=0.8 vs. 0.3±0.09mm, p=0.0026; DLVEDV 10±15.9ml, p=0.5 vs. 34.8±11.3ml, p=0.0081; ∆EF 2.4±1.2%, p=0.045 vs. -1.6±1.1, p=0.1 respectively). NYHA class significantly improved and the hospitalization rate was numerically reduced in the C.E.R.A. NOGA group, while three-year mortality was identical. Conclusions: Intramyocardial injection of C.E.R.A. is feasible, safe and possibly attenuates LV remodeling in ischemic HF patients with LV dysfunction compared to the systemic application.

Es hat sich viel getan in der Welt der Schlafmedizin in der Kardiologie, weshalb eine vollwertige Uberarbeitung des Positionspapiers „Schlafmedizin in der Kardiologie“ erforderlich wurde. In der aktuellen neuartigen Version finden sich nicht nur alle verfugbaren Studien, Literaturstellen und Updates zu Pathophysiologie, Diagnostik- und Therapieempfehlungen, sondern auch Ausblicke auf neue Entwicklungen und zukunftige Forschungserkenntnisse. Dieses uberarbeitete Positionspapier gibt Empfehlungen fur Diagnostik und Therapie von Patienten mit kardiovaskularen Erkrankungen mit schlafassoziierten Atmungsstorungen und erteilt daruber hinaus einen fundierten Uberblick uber verfugbare Therapien und Evidenzen, gibt aber ebenso Ratschlage wie mit Komorbiditaten umzugehen ist. Insbesondere enthalt dieses uberarbeitete Positionspapier aktualisierte Stellungnahmen zu schlafassoziierten Atmungsstorungen bei Patienten mit koronarer Herzerkrankung, Herzinsuffizienz, arterieller Hypertonie, aber auch fur Patienten mit Vorhofflimmern. Daruber hinaus finden sich erstmals Empfehlungen zur Telemedizin als eigenes, neues Kapitel. Dieses Positionspapier bietet Kardiologen sowie Arzten in der Behandlung von kardiovaskularen Patienten die Moglichkeit einer evidenzbasierten Behandlung der wachsend bedeutsamen und mit zunehmender Aufmerksamkeit behafteten Komorbiditat schlafassoziierter Atmungsstorungen. Und nicht zuletzt besteht mit diesem neuen Positionspapier eine enge Verknupfung mit dem neuen Curriculum Schlafmedizin der Deutschen Gesellschaft fur Kardiologie, weshalb dieses Positionspapier eine Orientierung fur die erworbenen Fahigkeiten des Curriculums im Umgang von kardiovaskularen Patienten mit schlafassoziierten Atmungsstorungen darstellt.

Die Antikoagulation hat eine zentrale Rolle im prahospitalen Management des akuten Koronarsyndroms. Viele Patienten werden heute dauerhaft mit neuen oralen Antikoagulanzien (NOAK) behandelt und weisen ein erhohtes Blutungsrisiko durch die zusatzliche Gabe eines Gerinnungshemmers auf. Derzeit gibt es keine expliziten Empfehlungen der Fachgesellschaften zur prahospitalen antikoagulatorischen Therapie bei diesen Patienten. Daher fasst das folgende Konsensuspapier den aktuellen Wissensstand zusammen und formuliert Empfehlungen fur die prahospitale Antikoagulation bei dieser speziellen Patientengruppe. Zusammenfassend sollen Patienten, die ein akutes Koronarsyndrom mit ST-Hebungen aufweisen, unabhangig von der letzten Einnahme eines neuen oralen Antikoagulans Acetylsalicylsaure (ASS) und unfraktioniertes Heparin erhalten. Patienten mit pektanginosen Beschwerden und fehlendem Nachweis von ST-Hebungen sollen ASS appliziert bekommen, wahrend Heparin nur nach individueller Nutzen-Risiko-Abwagung indiziert ist.

Left atrial appendage occlusion (LAAO) is recommended for patients with atrial fibrillation at increased stroke risk, where effective long-term oral anticoagulation (OAC) is not feasible. In order to assess long-term safety of LAAO with aspirin monotherapy or no therapy, we aimed to report on patients with the Watchman LAAO device (Boston Scientific) once postimplantation intensified antiplatelet or anticoagulation therapy is discontinued.A total of 1025 patients scheduled for elective LAAO therapy prospectively consented for participation in the EWOLUTION registry; 1005 patients received a successful implant and were followed for 2 years. We identified 766 patients in EWOLUTION on single-antiplatelet therapy (SAPT; n = 639) or no therapy (n = 127) for ≥1 year following LAAO.Three to 6 months after LAAO, 766 patients were switched to SAPT or no therapy and were followed for at least 1 year until the study's conclusion or with events while on SAPT/ no therapy; mean time on SAPT/no therapy was 536.56 ± 177.59 days. Patients experienced 1.4 ischemic strokes per 100 patient years (PY) despite a CHA2DS2-VASC score of 4.3 ± 1.6. Major nonprocedural bleeding rates were low, with 1.3 major bleeds per 100 PY with a mean HAS-BLED score of 2.2 ± 1.2. Furthermore, the ischemic stroke rate in the SAPT/no-therapy subgroup was similar to the whole EWOLUTION collective and high-risk subgroups; the bleeding rate was even lower. When analyzed separately, strokes (2.1/100 PY) and bleedings (1.4/100 PY) of the no-therapy subgroup were similar to patients on SAPT (strokes 0.7/100 PY [P=.70]; bleedings 1.4/100 PY [P=.90]).Outcome data of patients on SAPT/no therapy for ≥1 year following Watchman implantation in the EWOLUTION registry suggest the efficacy and safety of LAAO.

The new-generation WATCHMAN FLX (Boston Scientific) device for left atrial appendage occlusion has been modified in various aspects to improve procedural results. No comparison of the WATCHMAN FLX device with the previous WATCHMAN device is available.We aimed to compare procedural results with WATCHMAN FLX in patients on dual antiplatelet therapy at ∼3 months with data with WATCHMAN (EWOLUTION [Registry on WATCHMAN Outcomes in Real-Life Utilization]).One hundred sixty-four consecutive patients receiving the WATCHMAN FLX device in 4 European centers were included in the retrospective ALSTER-FLX registry. As a control group for a matched-pair analysis, 1020 patients treated with the WATCHMAN device and data up to first follow-up (∼3 months) from EWOLUTION were used.Implantation was successful in all ALSTER-FLX patients (100%) and similar to results in EWOLUTION (99%) (P = .2). We observed no stroke or device embolization in ALSTER-FLX similar to EWOLUTION (stroke 0.5%, device embolization 0.4%) at 3 months. Numerically less ALSTER-FLX patients (2.4%) developed a device-associated thrombus as compared with 3.7% EWOLUTION patients, yet without reaching statistical significance after matching (median [95% confidence interval] device-associated thrombus pairwise event difference 2 [0-6]; P = .1). WATCHMAN FLX implantation was associated with a significant higher sealing rate compared with EWOLUTION at 3 months (ALSTER-FLX 90% vs EWOLUTION 79.4%; P = .039 after matching). Major nonprocedural bleeding events and mortality were similar after matching (median event difference for bleeding 0 [-3 to 3]; P = .6 and death 1 [-2 to 4]; P = .3).Periprocedural, early 3-month outcomes with WATCHMAN FLX demonstrate a similar safety profile and an improved sealing rate compared to the WATCHMAN device.

Both balloon-expandable and self-expanding transcatheter aortic valves are used for transcatheter aortic valve implantation (TAVI). We compared procedural and clinical outcome variables of Sapien 3 and Evolut R/Pro in an all-comers collective.In this single-center registry, patients were consecutively treated with the Sapien 3 from November 2014 to March 2017 (n = 129) and from April 2017 to December 2018 mainly (95%) with the Evolut R/Pro (n = 124), due to a switch in the main TAVI supplier driven by hospital management. Data were retrospectively analyzed before and after the switch.One-year follow-up data were available for 122 (94%) of the Sapien and 112 (90%) of the Evolut patients. Baseline characteristics were comparable (EuroSCORE: Sapien 21.8 ± 0.9% vs Evolut 22.5 ± 0.8%; P=.20). Evolut implantation was associated with a higher radiation dose (Sapien 35770 ± 2345 mGy•cm² vs Evolut 85072 ± 8202 mGy•cm²; P.001), more postimplantation balloon dilations (Sapien 17.1% vs Evolut 37.1%; P.001), but similar procedure time (Sapien 75.2 ± 3.8 min vs Evolut 74.6 ± 3 min; P=.30). In-hospital mortality (Sapien 3.1% vs Evolut 4.0%; P=.70), all-cause mortality (Sapien 13.2% vs Evolut 15.3%; P=.70), all-stroke rate (Sapien 1.5% vs Evolut 6.5%; P=.05), and pacemaker implantation rate (Sapien 13.2% vs Evolut 18.5%; P=.30) were similar at 1 year. Permanent pacemaker rate was numerically higher in the first 6 months with Evolut (6 months 26.7% vs6 months 16%; P=.62); furthermore, radiation dose and balloon dilations also suggest a learning curve with Evolut.Switching from Sapien 3 to Evolut R/Pro was not associated with a difference regarding periprocedural or 1-year clinical outcomes.

Der Einsatz eines Okkluders fur das Vorhofohr („left atrial appendage“ [LAA]) erfolgt in Europa uberwiegend wegen Kontraindikationen fur die orale Antikoagulation (OAK). Daher wird das klassische Schema aus der PROTECT-AF-Studie (Vitamin-K-Antagonist plus Acetylsalicylsaure) beim Watchman®- und Amulet®-LAA-Okkluder (St. Jude Medical/Abbott, Eschborn, Deutschland) meist zugunsten einer dualen Antiplattchentherapie (DAPT) verlassen. Uber viele Jahre wurden Patienten mit LAA-Okkluder uber 1–6 Monate mit DAPT behandelt. Der aktuelle Standard sieht eine DAPT fur 3 Monate gefolgt von einer dauerhaften Monotherapie mit Acetylsalicylsaure vor, falls im transosophagealen Echokardiogramm zu diesem Zeitpunkt kein Thrombus am LAA-Okkluder nachgewiesen wird. Bei Patienten mit hohem Blutungsrisiko kann nach Nutzen-Risiko-Abwagung die Plattchenhemmung nach 3 Monaten komplett beendet werden. Randomisierte Studien zur Frage, ob Blutungen und Schlaganfalle bzw. Embolien bei Patienten mit LAA-Okkluder unter DAPT seltener als unter OAK auftreten, fehlen jedoch bislang. Alternativ konnen nach den Erfahrungen des EWOLUTION-Registers auch nicht-Vitamin-K-abhangige orale Antikoagulanzien (NOAK) mit geringem Blutungs- und Thrombusrisiko eingesetzt werden. Bei Patienten mit suboptimalem Implantationsergebnis, Thrombusnachweis auf dem Okkluder oder speziellen Risikofaktoren muss vom Standardschema abgewichen und gegebenenfalls eine dauerhafte Therapie mit DAPT oder NOAK angewandt werden. Thromben auf dem LAA-Okkluder kommen bei etwa 4–6 % der Patienten vor und sind zumindest kurzfristig mit einem sehr niedrigen Schlaganfallrisiko assoziiert.

NOAC therapy has become the standard for stroke prevention in patients with atrial fibrillation. Yet some patients suffer extracranial bleeding events or have other reasons to seek non-pharmacologic stroke protection. LAA occlusion with the WATCHMAN device has been proven safe and effective for such patients and is now recommended in current guidelines for this patient group; other devices also seek approval.

In Europe left atrial appendage occluders (LAAO) are most frequently used in patients with contraindications for oral anticoagulation (OAC); therefore, the classical therapeutic OAC scheme from the PROTECT-AF trial (vitamin K antagonist plus acetylsalicylic acid) is usually changed to dual anti-platelet therapy (DAPT) after implantation of a Watchman® or Amulet® LAAO (St. Jude Medical/Abbott, Eschborn, Germany). For many years, patients with an LAAO received DAPT for 1-6 months. The current standard comprises DAPT for 3 months, followed by permanent acetylsalicylic acid monotherapy if the transesophageal echocardiogram excludes a thrombus at the site of the LAAO. In patients with high risk of bleeding, anti-platelet therapy can be stopped at 3 months after an individual risk-benefit calculation. There are no randomized studies on the risk of bleeding and stroke/embolism in patients with an LAA occluder under DAPT versus OAC. Experience from the EWOLUTION registry shows that NOACs may be used as an alternative with low bleeding and thrombus risks. In patients with a suboptimal implantation result, thrombus on the LAAO or specific risk factors, variations of the standard scheme have to be applied and if necessary lifelong DAPT or NOAC therapy has to be used. Thrombi on the LAAO occur in approximately 4-6% of patients and are associated with a very low short-term stroke risk.

Correct sizing of the ostium is a crucial step in left atrial appendage (LAA) occlusion procedures. However, unfavorable anatomy of the ostium often complicates the assessment of the true ostium diameter. We hypothesized that area-derived diameter (ADD) and perimeter-derived diameter (PDD) from three-dimensional transesophageal echocardiogram (3D-TEE) can facilitate this step of the procedure as compared with two-dimensional (2D) measurements.For 55 patients within the ALSTER-LAA registry, retrospective analysis of PDD and ADD was correlated with 2D measurements used during the procedure to ascertain correct size of the Watchman device (Boston Scientific). The observed data were put into relation to the calculated area of the device with 10%-30% compression and the clinical outcome after 30 days. 3D area and perimeter measurements of the LAA ostium matched the calculated range of the different device sizes. Recapture during implantation, gaps5 mm, and device size changes were more often observed when ADDs would also have suggested the use of a larger device.3D ADDs and PDDs are feasible to use in device size decisions. Employing these measurements may allow operators to further reduce intraprocedural recapture maneuvers, peridevice leakage, and device size changes.

Arterial hypertension (HTN) is one of the major risk factors for cardiovascular disease, and also leads to hypertensive heart disease, hypertensive nephropathy, cerebrovascular disease as well as cardiac arrhythmias. Despite receiving antihypertensive drugs, patients often do not reach their individual guideline blood pressure (BP) levels. Interventional sympathetic renal artery denervation (RDN) has been demonstrated to successfully lower blood pressure in patients with systolic blood pressure values ≥160 mmHg while on three or more antihypertensive drugs. The SymplicityTM device (Medtronic, Palo Alto, CA, USA) was shown to be safe, with side effects rarely occuring. Recent data from registries show that this procedure is efficient in about 70% of patients. New upcoming devices aim to significantly reduce procedure time and post-procedural complications through new concepts and strategies for RDN, and may possibly improve its effectiveness. Currently, radiofrequency (RF) is the dominant modality for RDN, but devices using energy delivery via ultrasound (US) have been developed. Intravascular optical coherence tomography (IVOCT) is a novel invasive diagnostic modality, which is able to analyse endothelial integrity at a resolution of approximately 10 μm. Recent IVOCT findings after RDN find evidence for endothelial damage and thrombus formation introduced through RDN, yet the clinical significance is uncertain since similar images are obtained when analysing coronary arteries after stenting. Nevertheless, irrigated RDN devices could reduce the observed issues and deliver more energy to deeper tissue levels similar to that observed in ablation of atrial fibrillation. This article provides an overview of currently available data and devices; furthermore we present a case report on the OneShotTM Renal Denervation System (Covidien, Campbell, CA, USA) and preliminary findings of IVOCT examinations after RDN.

The need for effective stroke prevention in patients with atrial fibrillation increases with age. Several studies found platelet inhibition to be ineffective. Thus, for many years oral anticoagulation had been the only pharmacological option. Given the associated bleeding risk especially in the elderly warfarin is underused. Intracerebral bleeding is particularly problematic as it usually leads to dramatic clinical consequences. The introduction of non-vitamin K antagonists (NOAC) - specific oral anticoagulants directed at factor X or II - has reduced the risk of intracranial bleeding. Yet the rate of total bleeding events, particularly gastrointestinal, bladder and skin bleeding, largely remained unchanged. In addition, compliance to these drugs is an issue. Recent guidelines have incorporated interventional stroke protection, namely LAA occluder therapy, to be part of the routine treatment algorithm. This chapter summarizes the current evidence regarding the different options for stroke prevention in patients with atrial fibrillation.

Despite the large variety of LAA anatomies, Watchman implantation can be standardized to minimize periprocedural risk, device manipulation and maximize procedural success. Experienced operators achieve complete closure with the first device release in around 80% of patients. In experienced hands, 98% of all anatomies can be occluded successfully without prior screening or exclusion of particular anatomies. For LAA closure, specific device features like frame structure, location of barbs and the depth of the PET fabric needs to be considered. Inferior and posterior location of the transseptal puncture has proven to be key to a straight-forward device positioning and release. Sheath exchange over a stiff wire in the pulmonary vein minimizes pericardial effusion, initially observed when the sheath was exchanged over a wire already located in the fragile structure of the LAA. Sizing of the landing zone by angio and echo measurements needs specific anatomic understanding similar to other structural heart interventions. A sizing scheme is provided that leads to around 20% compression which most operators favor over the initial recommendation of between 8 and 20%. Release criteria (“PASS”) needs to be met prior to disconnecting the device from the delivery cable in order to prevent embolization – a very rare event particularly with the Watchman (

Access to the left atrium for LAA closure has been standardized to optimize the entry to the LAA and limit complications. Following femoral vein access, transseptal crossing from the right atrium to the left atrium in an inferior and posterior location of the Fossa ovalis has proven to be a key factor to a straightforward device positioning and release. This is best achieved with a Brockenbrough needle delivered to the Fossa ovalis through a SL1 sheath stabilized with a dilator. TEE guiding for transseptal puncture is used by most operators and highly recommended to avoid complications and optimize access.

Different anatomies and occluder position strategies are required to successfully treat negotiate the various anatomies classified as single lobe, dual lobe, windsock, chicken wing and broccoli type. This chapter describes the default strategies to occlude the various LAA anatomic configurations employing the Watchman device. In the experience of this operator, implantation of the Watchman device is not limited by LAA depth—the chapter describes several strategies to negotiate shallow anatomies. The distal part of the device is usually positioned in the most superior/anterior LAA lobe as the default strategy. Different to the Amulet device, the Watchman device distal part stays exactly at the position device release is started. No proximal movement is observed during release. The Watchman occluder is positioned such that the proximal, fabric covered part of the device spans the complete LAA neck preventing any thrombus from the distal lobes to enter the circulation.

As of early 2017 prospective, multicenter data on LAA closure techniques with external data monitoring are only available for the Watchman device. The two randomized trials (PROTECT-AF and PREVAIL) as well as the prospective multicenter registries (ASAP, CAP1 & 2, EWOLUTION) included 2406 patients in total between 2005 and 2015. The data provide good evidence for both safety and efficacy of Watchman LAA closure in comparison to warfarin therapy. Retrospective analysis of 1047 patients that received the ACP device between 2008 and 2013 described similar results. New studies on several new devices are planned following FDA approval of the Watchman device in 2015.

Wnt/β-catenin signalling controls adult heart remodelling in part via regulation of cardiac progenitor cell (CPC) differentiation. An enhanced understanding of mechanisms controlling CPC biology might facilitate the development of new therapeutic strategies in heart failure. We identified and characterized a novel cardiac interaction between Krueppel-like factor 15 and components of the Wnt/β-catenin pathway leading to inhibition of transcription. In vitro mutation, reporter assays and co-localization analyses revealed that KLF15 requires both the C-terminus, necessary for nuclear localization, and a minimal N-terminal regulatory region to inhibit transcription. In line with this, functional Klf15 knock-out mice exhibited cardiac β-catenin transcriptional activation along with functional cardiac deterioration in normal homeostasis and upon hypertrophy. We further provide in vivo and in vitro evidences for preferential endothelial lineage differentiation of CPCs upon KLF15 deletion. Via inhibition of β-catenin transcription, KLF15 controls CPC homeostasis in the adult heart similar to embryonic cardiogenesis. This knowledge may provide a tool for reactivation of this apparently dormant CPC population in the adult heart and thus be an attractive approach to enhance endogenous cardiac repair. peerReviewed

AIMS: Low-dose epoetin-{beta} improved neo-angiogenesis and cardiac regeneration in experimental models of ischaemic cardiomyopathy without raising haemoglobin. No clinical study has tested this approach to date. METHODS AND RESULTS: We performed a randomized, placebo-controlled, double-blind, single-centre study of 35 IU/kg body weight epoetin-{beta} given subcutaneously once weekly for 6 months started within 3 weeks after successful percutaneous coronary intervention (PCI). Patients were included if they presented with a lesion within the proximal segment of the left anterior descending artery, the right coronary artery, or circumflex and had symptomatic heart failure. Patients with ST-segment elevation due to an acute myocardial infarct were excluded. The outcome variables were measured at baseline and at 6 months. Primary outcome measure was individual change in ejection fraction; secondary outcome was safety, change in N-terminal pro-brain natriuretic peptide, and peak VO(2). Twenty-four patients completed the 6-month treatment course. No adverse event related to the treatment occurred. Low-dose epoetin-{beta} following PCI significantly improved global ejection fraction as measured by echocardiography (EPO: {delta}EF 5.2 +/- 2.0%, P= 0.013; placebo: DeltaEF 0.3 +/- 1.6%, P= 0.851; P= 0.019 for the inter-group difference) and cardiac magnetic resonance (EPO: DeltaEF 3.1 +/- 1.6%, P= 0.124; placebo: -1.9 +/- 1.2%, P= 0.167; P= 0.042 for the inter-group difference). N-terminal pro-brain natriuretic peptide levels decreased in both groups without significant inter-group differences. Peak VO(2) levels increased significantly by 3.9 +/- 1.1% (P< 0.05) in the EPO group, whereas in the placebo group the increase did not reach statistical significance ({delta}peak VO(2) 3.0 +/- 1.6, P = ns). No significant difference regarding peak VO(2) was observed between the EPO and placebo groups. CONCLUSIONS: Low-dose epoetin-{beta} treatment following PCI is safe and feasible, and has possible beneficial effects on global ejection fraction and measures of exercise capacity. Extended low-dose epoetin-{beta} treatment warrants further mechanistic studies as well as larger clinical trials. Clinical Trial Registration Information: NCT00568542.

A-kinase anchoring proteins (AKAPs) tether protein kinase A (PKA) and other signaling proteins to defined intracellular sites, thereby establishing compartmentalized cAMP signaling. AKAP-PKA interactions play key roles in various cellular processes, including the regulation of cardiac myocyte contractility. We discovered small molecules, 3,3′-diamino-4,4′-dihydroxydiphenylmethane (FMP-API-1) and its derivatives, which inhibit AKAP-PKA interactions in vitro and in cultured cardiac myocytes. The molecules bind to an allosteric site of regulatory subunits of PKA identifying a hitherto unrecognized region that controls AKAP-PKA interactions. FMP-API-1 also activates PKA. The net effect of FMP-API-1 is a selective interference with compartmentalized cAMP signaling. In cardiac myocytes, FMP-API-1 reveals a novel mechanism involved in terminating β-adrenoreceptor-induced cAMP synthesis. In addition, FMP-API-1 leads to an increase in contractility of cultured rat cardiac myocytes and intact hearts. Thus, FMP-API-1 represents not only a novel means to study compartmentalized cAMP/PKA signaling but, due to its effects on cardiac myocytes and intact hearts, provides the basis for a new concept in the treatment of chronic heart failure.

On pathological stress, the heart reactivates several signaling pathways that traditionally were thought to be operational only in the developing heart. One of these pathways is the WNT signaling pathway. WNT controls heart development but is also modulated during adult heart remodeling. This review summarizes the currently available data regarding WNT signaling during left ventricular (LV) remodeling. Upstream, soluble frizzled-related proteins (sFRPs) block WNT-dependent activation of the canonical WNT pathway. By inhibition of WNT activation, these factors also reduce β-catenin–dependent transcription by altering the ratio of cytoplasmic/nuclear β-catenin. In experimental settings, sFRPs injected into the heart attenuated LV remodeling. sFRPs are secreted from autologous bone marrow–derived mononuclear cells. Disheveled is a signaling intermediate of both the canonical and noncanonical WNT pathway. Similarly to the effect of sFRP, depletion of a disheveled isoform attenuated LV remodeling. In contrast, disheveled activation led to progressive dilated cardiomyopathy. Inhibition of nuclear β-catenin signaling downstream of the canonical WNT pathway significantly reduced postinfarct mortality and functional decline of LV function following chronic left anterior descending coronary artery ligation. WNT signaling also affects mobilization and homing of bone marrow–derived vasculogenic progenitor cells. Finally, heart-specific WNT/β-catenin interaction partners have been identified that will possibly allow targeting this pathway in a tissue-specific manner. In summary, the WNT pathway plays a pivotal role in adult cardiac remodeling and may be suitable for therapeutic interventions. Currently, several molecular and cellular mechanisms whereby WNT inhibition attenuates LV remodeling are proposed. Reactivation of the developmental program to restore functional LV myocardium from resident precursor cells may significantly contribute to this process.

In the present study, IL (interleukin)-1β increased GM-CSF (granulocyte/macrophage colony-stimulating factor) expression from pulmonary A549 cells and primary HBE (human bronchial epithelial) cells. These responses were repressed by the glucocorticoid dexamethasone, allowing the use of A549 cells as a relevant model. IL-1β induced GM-CSF release into the culture medium by 6 h and in cell lysates (cytosolic) at 2 h. These effects were profoundly inhibited by dexamethasone, yet IL-1β-induced GM-CSF mRNA and unspliced nRNA (nuclear RNA; a surrogate of transcription rate) were modestly inhibited by dexamethasone at times up to 2 h. Although this indicates an effect on protein synthesis, actinomycin D chase experiments also indicated post-transcriptional repression by dexamethasone. Dexamethasone-dependent mRNA repression increased with time and was prevented by translational blockade. In addition, dexamethasone and the dissociated steroid RU24858 repressed GM-CSF release in an actinomycin D-sensitive manner, thereby implicating glucocorticoid-induced gene expression. At 2 h, IL-1β-induced expression of GM-CSF protein, but not mRNA, was sensitive to the MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] inhibitors PD098059 and U0126. Although this indicates a role for the MEK/ERK pathway in GM-CSF translation, PD098059 subsequently destabilized GM-CSF mRNA. Dexamethasone and RU24858 both reduced IL-1β-induced ERK phosphorylation and increased MKP-1 (MAPK phosphatase-1) expression. Inhibition of ERK phosphorylation was reproduced by MKP-1 overexpression and prevented by MKP-1-targeting siRNA (small interfering RNA). Since MKP-1 prevented GM-CSF expression by transcriptional, post-transcriptional and translational processes, we propose that glucocorticoids induce MKP-1 expression to reduce both MEK/ERK activation and GM-CSF protein synthesis. Thus de novo gene expression, particularly of MKP-1, is involved in the repressive effects of glucocorticoids.

We have previously shown that cardiac-specific inhibition of NF-kappaB attenuates angiotensin II (AngII)-induced left ventricular (LV) hypertrophy in vivo. We now tested whether NF-kappaB inhibition is able to block LV remodelling upon chronic pressure overload and chronic AngII stimulation.Cardiac-restricted NF-kappaB inhibition was achieved by expression of a stabilized IkappaBalpha mutant (IkappaBalphaDeltaN) in cells with an active alpha-myosin heavy chain (alphaMHC) promoter employing the Cre/lox technique. Upon low-gradient trans-aortic constriction (TAC, gradient 21 +/- 3 mmHg), hypertrophy was induced in both male and female control mice after 4 weeks. At this time, LV hypertrophy was blocked in transgenic (TG) male but not female mice with NF-kappaB inhibition. Amelioration of LV hypertrophy was associated with activation of NF-kappaB by dihydrotestosterone in isolated neonatal cardiomyocytes. LV remodelling was not attenuated by NF-kappaB inhibition after 8 weeks TAC, demonstrated by decreased fractional shortening (FS) in both control and TG mice irrespective of gender. Similar results were obtained when TAC was performed with higher gradients (48 +/- 4 mmHg). In TG mice, FS dropped to similar low levels over the same time course [FS sham, 29 +/- 1% (mean +/- SEM); FS control + 14 days TAC, 13 +/- 3%; FS TG + 14 days TAC, 9 +/- 5%]. Similarly, LV remodelling was accelerated by NF-kappaB inhibition in an AngII-dependent genetic heart failure model (AT1-R(alphaMHC)) associated with significantly increased cardiac fibrosis in double AT1-R(alphaMHC)/TG mice.NF-kappaB inhibition attenuates cardiac hypertrophy in a gender-specific manner but does not alter the course of stress-induced LV remodelling, indicating NF-kappaB to be required for adaptive cardiac hypertrophy.

The armadillo-related protein β-catenin has multiple functions in cardiac tissue homeostasis: stabilization of β-catenin has been implicated in adult cardiac hypertrophy, and downregulation initiates heart formation in embryogenesis. The protein is also part of the cadherin/catenin complex at the cell membrane, where depletion might result in disturbed cell–cell interaction similar to N-cadherin knockout models. Here, we analyzed the in vivo role of β-catenin in adult cardiac hypertrophy initiated by angiotensin II (Ang II). The cardiac-specific mifepristone-inducible αMHC-CrePR1 transgene was used to induce β-catenin depletion (loxP-flanked exons 3 to 6, β-cat Δex3–6 mice) or stabilization (loxP-flanked exon 3, β-cat Δex3 mice). Levels of β-catenin were altered both in membrane and nuclear extracts. Analysis of the β-catenin target genes Axin2 and Tcf-4 confirmed increased β-catenin–dependent transcription in β-catenin stabilized mice. In both models, transgenic mice were viable and healthy at age 6 months. β-Catenin appeared dispensable for cell membrane function. Ang II infusion induced cardiac hypertrophy both in wild-type mice and in mice with β-catenin depletion. In contrast, mice with stabilized β-catenin had decreased cross-sectional area at baseline and an abrogated hypertrophic response to Ang II infusion. Stabilizing β-catenin led to impaired fractional shortening compared with control littermates after Ang II stimulation. This functional deterioration was associated with altered expression of the T-box proteins Tbx5 and Tbx20 at baseline and after Ang II stimulation. In addition, atrophy-related protein IGFBP5 was upregulated in β-catenin–stabilized mice. These data suggest that β-catenin downregulation is required for adaptive cardiac hypertrophy.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and the rate of ischemic stroke attributed to non-valvular AF is estimated at 5% per year. Several multi-center studies established left atrial appendage closure as a safe and effective alternative to oral anticoagulation, but there is a need for additional real world data.The purpose of this observational, prospective, single-arm, multicenter clinical study is to compile real-world clinical outcome data for WATCHMAN™ LAA (left atrial appendage) Closure Technology. One thousand subjects at up to 70 institutions in Europe, the Middle East, and Russia will be enrolled. Patients will be followed for 2 years after WATCHMAN implantation, according to standard medical practice. Primary endpoints include procedural and long-term data including stroke/embolism, bleeding, and death. This article presents the background of the LAAC device and describes the design of the study.Results for peri-procedural analyses are expected toward the end of 2015; long-term follow-up data are expected in the latter half of 2017.The EWOLUTION study will formally expand knowledge of LAA closure into a broader real world setting. © 2015 Wiley Periodicals, Inc.

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) reporter constructs containing up to 3.3 kb of upstream promoter sequence were transiently transfected into both Jurkat and HUT78 human T-cell lines. In Jurkat cells, stimulation with phorbol 12-myristate 13-acetate (PMA) plus phytohemaglutinin (PHA) produced robust increases in reporter activity, whereas HUT78 cells showed low levels of reporter induction attributable to constitutive nuclear factor (NF)-kappaB activity. Following mutation of either the proximal NF-kappaB site (-85/-76) or the activator protein1 (AP-1) motif within the conserved lymphokine element 0 (CLE0) site (-54/-31), reporter activity was markedly reduced in both cell lines. Despite this dependence on NF-kappaB and CLE0/AP-1, GM-CSF reporter activity was unaffected by dexamethasone in either cell line. Similarly, an NF-kappaB-dependent reporter was also not repressed by dexamethasone, yet GM-CSF release from HUT78 T cells was inhibited. These data therefore confirm a critical role for both NF-kappaB and CLE0 sites in GM-CSF promoter activation and indicate that NF-kappaB may not mediate glucocorticoid-dependent repression of GM-CSF in these cells.

In pulmonary A549 cells, the protein kinase C (PKC) inhibitor, Ro 31-8220, and the phosphotidylcholine-specific phospholipase C inhibitor, D609, prevent NF-kappaB-dependent transcription, yet NF-kappaB DNA binding is unaffected (Bergmann, M., Hart, L., Lindsay, M., Barnes, P. J., and Newton, R. (1998) J. Biol. Chem. 273, 6607-6610). We now show that this effect also occurs in BEAS-2B bronchial epithelial cells as well as with other PKC inhibitors (Go 6976, GF109203X, and calphostin C) in A549 cells. Similarly, phorbol ester, a diacylglycerol mimetic, activates NF-kappaB-dependent transcription and potentiates tumor necrosis factor alpha (TNFalpha)-induced NF-kappaB-dependent transcription, yet unlike TNFalpha, poorly activates IkappaB kinase (IKK) activity, IkappaBalpha degradation, or NF-kappaB DNA binding in both A549 and BEAS-2B cells. As phorbol ester-induced NF-kappaB-dependent transcription was relatively insensitive to the proteasome inhibitor, MG-132, PKC may affect NF-kappaB-dependent transcription via mechanisms other than the core IKK-IkappaB pathway. This is supported by Gal4 one hybrid analysis of p65/RelA transactivation, which was potentiated by TNFalpha and phorbol ester and was inhibited by Ro 31-8220 and D609. Additionally, a number of PKC isoforms, particularly the novel isoform PKCepsilon, induced p65/RelA transactivation. Phosphorylation of p65/RelA and cAMP-responsive element-binding protein (CREB)-binding protein (CBP) was increased by TNFalpha treatment and, in the case of CBP, was prevented by Ro 31-8220 or D609. However, p65/RelA-CBP interactions were unaffected by either compound. As this effect was not limited to NF-kappaB, but was a more general feature of inducible gene transcription, we suggest PKC isoforms may provide a point of intervention in diseases such as inflammation, or cancer, where activated gene expression is prominent.

Release of granulocyte macrophage-colony-stimulating factor (GM-CSF) from T cells is important in the differentiation, maturation, and survival of inflammatory cells. Here the induction of GM-CSF expression from T cells was dependent on transcription and translation and was prevented by dexamethasone. In primary human CD3(+) T cells, up to 3.3 kb of human GM-CSF promoter was strongly activated by PMA + PHA. Mutations in either the -85/-76 nuclear factor (NF)-kappaB site or the activator protein-1 region in the -54/-31 conserved lymphokine element 0 (CLE0) site substantially reduced promoter activity. Both GM-CSF promoter and NF-kappaB-dependent constructs were unresponsive to dexamethasone whereas the release of GM-CSF was potently repressed. Analysis of GM-CSF mRNA and protein expression at various time points and the effect of adding dexamethasone after the stimulus revealed the existence of potent mechanisms of inhibition acting at a translational level. The expression of tristetraproline and HuR, proteins that bind the AU-rich element in the GM-CSF 3'-untranslated region was unaffected by dexamethasone and overall AU-rich element binding activity was unaltered. Taken together our data support an important role for the NF-kappaB and CLE0 sites in the transcriptional control of GM-CSF expression in primary human T cells and suggest that post-transcriptional/translational mechanisms are key mediators of glucocorticoid-dependent repression.

Prostaglandin (PG) E2 release is induced in pulmonary A549 cells by the NF-kappaB-activating stimuli interleukin-1beta (IL-1beta) and phorbol 12-myristate 13-acetate (PMA). Adenoviral over-expression of IkappaBalphaDeltaN, a dominant NF-kappaB inhibitor, prevents NF-kappaB-dependent transcription and was used to qualify the role of NF-kappaB in the release of PGE2. IkappaBalphaDeltaN repressed IL-1beta-induced, but not PMA-induced, cycloxygenase-2 (COX-2) and microsomal prostaglandin E synthase (mPGES) expression. These data conclusively demonstrate a substantial role for NF-kappaB in the co-ordinate induction of COX-2, mPGES and in the corresponding release of PGE2 by IL-1beta. However, other pathways are primarily responsible for PGE2 release induced by PMA.

Background A variety of pathologic stimuli lead to apoptosis of cardiomyocytes. Survival factors like insulin-like growth factor-I (IGF-I) exert anti-apoptotic effects in the heart. Yet the underlying signaling pathways are poorly understood. Methods and Results In a model of hypoxia-induced apoptosis of cultured neonatal cardiomyocytes, IGF-I prevented cell death in a dose-dependent manner. Antiapoptotic signals induced by IGF-I are mediated by more than one signaling pathway, because pharmacological inhibition of the phosphatidylinositol-3-OH-kinase (PI3K) or the mitogen-activated protein kinase kinase (MEK1) signaling pathway both antagonize the protective effect of IGF-I in an additive manner. IGF-I-stimulation was followed by a PI3K-dependent phosphorylation of AKT and BAD and an MEK1-dependent phosphorylation of extracellular signal-regulated kinase (ERK) 1 and ERK2. IGF-I also induced phosphorylation of cAMP response element-binding protein (CREB) in a PI3K- and MEK1-dependent manner. Ectopic overexpression of a dominant-negative mutant of CREB abolished the antiapoptotic effect of IGF-I. Protein levels of the antiapoptotic factor bcl-2 increased after longer periods of IGF-I-stimulation, which could be reversed by pharmacological inhibition of PI3K as well as MEK1 and also by overexpression of dominant-negative CREB. Conclusions In summary, our data demonstrate that in cardiomyocytes, the antiapoptotic effect of IGF-I requires both PI3K- and MEK1-dependent pathways leading to the activation of the transcription factor CREB, which then induces the expression of the antiapoptotic factor bcl-2.

Heart-specific inhibition of survival pathway gp130 was recently shown to sensitize transgenic mice towards stress stimuli, resulting in rapid onset of cardiac dilatation and heart failure. In order to identify further survival pathways we evaluated the role of transcription factor nuclear factor-kappa B (NF-kappa B) in tumour necrosis factor-alpha (TNF-alpha)-induced apoptosis of cardiomyocytes. TNF-alpha stimulation (10 ng/ml) of both H9c2 cells and primary cardiomyocytes isolated from neonatal Wistar rats resulted in rapid nuclear translocation of NF-kappa B complexes. The NF-kappa B complexes consisted of rel-proteins p50 and p65, as revealed by supershift analysis. Addition of proteasome inhibitor MG132 or adenoviral expression of a truncated I kappa B alpha (I kappa B Delta N) inhibited TNF-alpha-induced NF-kappa B nuclear translocation in a dose-dependent manner. Both neonatal cardiomyocytes and H9c2 cells were resistant to TNF-induced apoptosis. However, specific inhibition of NF-kappa B activation by Ad5-I kappa B alpha Delta N (MOI=50) or MG132 (5 microm) increased apoptosis as measured by subG1-assay (H9c2 cells) and annexin V binding/propidium iodide (neonatal cardiomyocytes, FACS-analysis: 7+/-2% to 26+/-5% annexin V positive/PI negative), respectively. TUNEL-assay double-stained with anti-alpha-sarcomeric actin confirmed apoptosis of neonatal cardiomyocytes. Furthermore, caspase-3 activation was increased by 52+/-7% in neonatal cardiomyocytes after TNF alpha+Ad5-I kappa B alpha Delta N compared to TNF alpha+Ad5-control treatment. Protein levels of hiAP1, hiAP2, x-iAP, bcl-2 and bcl-x(L) were neither downregulated by NF-kappa B inhibition nor upregulated by TNF-alpha stimulation. In summary, cardiomyocytes utilize transcription factor NF-kappa B to activate survival factors in the context of TNF-alpha stimulation. As locally increased levels of TNF-alpha have been detected in heart failure, NF-kappa B activity is essential for cellular homeostasis in the heart.

Two closely related IκBα kinases as well as the upstream kinase, NIK, which integrates interleukin-1β (IL-1β)- and tumor necrosis factor (TNF)-α-dependent activation of the transcription factor NF-κB have recently been described. However, in this emerging pathway the role of previously identified components of cytokine-induced NF-κB activation, namely phosphatidylcholine-specific phospholipase C and protein kinase C, remains unclear. We now show that, in A549 human alveolar epithelial cells, the activation of a stably transfected NF-κB-dependent reporter gene by TNF-α and IL-1β is completely blocked by the phosphatidylcholine-specific phospholipase C inhibitor D609 and the protein kinase C inhibitor RO31-8220. However, IL-1β-induced IκBα degradation as well as NF-κB nuclear translocation and DNA binding, as determined by Western blot and electro-mobility shift assay, respectively, are not affected by these inhibitors. A similar effect, although less pronounced, is observed with the p38 mitogen-activated protein kinase inhibitor SB 203580. On the basis of these data we propose the existence of a second signaling pathway induced by IL-1β and TNF-α that is activated in parallel to the cascade leading to IκBα degradation and is specifically required for NF-κB-dependent transcriptional competency.

Recent data suggest that erythropoietin (Epo) can improve cardiac function following ischemia reperfusion injury. We found EpoR to be prominently expressed in embryonic rather than adult mouse heart. In the latter EpoR expression was confined to interstitial cells. We isolated the non-myocyte fraction of adult mouse hearts by enzymatic digestion and straining (pore size: 30 µm) and found a 4-fold higher EpoR expression compared to unselected cardiac cells (n=3). Flow cytometry (FC) revealed that 24±3% of this heterogeneous cell pool expressed EpoR (n=3) and 11±2% co-expressed αMHC. Half of the αMHC+ cells stained positive for Ki67, consistent with FC showing that 49±7% αMHC+/EpoR+ cells were in S and G2 phase (n=3; vs. 13±3% in αMHC-/EpoR-; n=3). Interestingly, co-culture with neonatal rat cardiomyocytes yielded EGFP+ cardiomyocyte-like cells. Since αMHC+ proliferated and differentiated in vitro we termed them cardiomyogenic precursors (CMPs). Epo treatment of the non-myocyte pool enhanced Akt phosphorylation (n=6/group) and increased CMP abundance in vitro (2-fold; n=3). Cell cycle arrest abrogated the aforementioned effect, suggesting that Epo influenced CMP proliferation. Finally, we tested the potential of Epo to protect against ischemia by enhancing CMP numbers in a model of myocardial infarction (MI). Following MI mice were treated twice with 2,000 U/kg Epo (i.p.). Ten weeks post MI echocardiography revealed blunted myocardial deterioration in mice receiving Epo (ΔEF=-11.18%, n=5) compared to control (ΔEF=-20.82%, n=6). FC revealed an enhanced αMHC+/cTnT+ cell pool in the Epo treated group (20.3±1.9% vs. 10.6±2.3% in control, n=8/6) 4 weeks post MI. In conclusion, we found that EpoR is expressed in a putative cardiomyogenic precursor cell pool in the adult heart. CMPs appear to proliferate in vitro and in vivo; with further enhanced proliferation under Epo administration. This may contribute to Epo mediated protection after MI and highlights the therapeutic effect of Epo upon ischemic cardiac injury. Whether these cells remain from embryogenesis or just constitute an immature myocyte population in the adult heart deriving from cardiomyocyte dedifferentiation needs to be further investigated.

In diseased hearts, estrogen (E2) has been shown to exert anti-hypertrophic actions. Little is known about the role of E2 in the healthy heart. Our initial aim was to characterize structurally and molecularly the effects of E2 in the healthy mouse heart. Two-month-old female C57Bl/6J mice were ovariectomized and randomized to an E2-containing or soy-free (control, CON) diet ( n = 17-18/group). The three-month physiological dose of E2 led to a higher relative heart weight compared with CON ( P < 0.001). We also confirmed increased cardiomyocyte cross-sectional area by E2 ( P < 0.01). No activation of the fetal gene program and no fibrosis were observed. Transcriptome analysis revealed induction of growth-related pathways by E2, such as the Wnt signaling pathway ( n = 5/group; adjusted P < 0.05). To further confirm activation of Wnt/β-catenin signaling, we verified increased nuclear β-catenin protein levels by E2 compared with CON ( P < 0.01) and hypothesized that β-catenin mediates the actions of E2. Cardiac deletion of β-catenin blunted the E2 effects on cardiac growth ( n = 13/group). Surprisingly, in wild-type littermates with the background C57Bl/6N, E2 decreased the relative heart weight and cardiomyocyte cross-sectional area compared with CON ( n = 7-11/group; P < 0.001). This was underlain by decreased nuclear β-catenin protein levels by E2 compared with CON ( P < 0.001). Furthermore, E2 increased glycogen synthase kinase 3β (GSK3β) phosphorylation and the endosomal/autophagosomal markers Rab5, Rab7 and LC3-II in C57Bl/6J but not C57Bl/6N mice. Assessing a polymorphism linked to Snap29 , we confirmed higher Snap29 protein levels in C57Bl/6J than C57Bl/6N mice ( P < 0.01). This could lead to distinct regulation of endosomes and could be the potential cause of the strain difference. In conclusion, E2 regulates cardiac growth through β-catenin in a strain-specific manner. Collectively, we identified a molecular mechanism that demonstrates a divergent response of mouse sub-strains to E2.

The use of bioresorbable vascular scaffolds (BVS) in percutaneous coronary interventions holds great promise and the Absorb® BVS is increasingly used in clinical practice outside of controlled studies. However, questions have been raised concerning the delivery of the scaffold to complex lesions. We describe a case of successful delivery and implantation of two overlapping Absorb® BVS to a complex lesion in the left anterior descending artery. The crossing of the lesions was uneventful and after implantation a good acute result could be documented. A follow-up angiogram after 3 months proofed a stable midterm result. We thereby demonstrate the feasibility of delivering Absorb® BVS to more complex lesions than practiced so far in the setting of clinical trials.

The multiphasic regulation of the Wnt/β-catenin canonical pathway is essential for cardiogenesis in vivo and in vitro. To achieve tight regulation of the Wnt/β-catenin signaling, tissue- and cell-specific coactivators and repressors need to be recruited. The identification of such factors may help to elucidate mechanisms leading to enhanced cardiac differentiation efficiency in vitro as well as promote regeneration in vivo. Using a yeast-two-hybrid screen, we identified four-and-a-half-LIM-domain 2 (FHL2) as a cardiac-specific β-catenin interaction partner and activator of Wnt/β-catenin-dependent transcription. We analyzed the role of this interaction for early cardiogenesis in an in vitro model by making use of embryoid body cultures from mouse embryonic stem cells (ESCs). In this model, stable FHL2 gain-of-function promoted mesodermal cell formation and cell proliferation while arresting cardiac differentiation in an early cardiogenic mesodermal progenitor state. Mechanistically, FHL2 overexpression enhanced nuclear accumulation of β-catenin and activated Wnt/β-catenin-dependent transcription leading to sustained upregulation of the early cardiogenic gene Igfbp5. In an alternative P19 cell model, transient FHL2 overexpression led to early activation of Wnt/β-catenin-dependent transcription, but not sustained high-level of Igfbp5 expression. This resulted in enhanced cardiogenesis. We propose that early Wnt/β-catenin-dependent transcriptional activation mediated by FHL2 is important for the transition to and expansion of early cardiogenic mesodermal cells. Collectively, our findings offer mechanistic insight into the early cardiogenic code and may be further exploited to enhance cardiac progenitor cell activity in vitro and in vivo.

Erythropoietin (Epo) was shown to improve cardiac function following ischemia reperfusion mainly via neo-angiogenesis and anti-apoptotic mechanisms. We found EpoR expression to be particularly high in adult cardiac progenitor cells (CPCs). Thus, we reasoned that Epo may play a role in the biology of these cells. We isolated CPCs from adult C57BL/6 hearts by enzymatic digestion and filtration (pore size: 30 µm). By means of immunofluorescence microscopy (IF) and flow cytometry (FC) we analyzed EpoR expression in the CPCs. 24±3% of the investigated cardiac cells were positive for EpoR with 3±2% of these being c-kit+ and 28%±2% Sca-1+. 52% of the EpoR+ cells expressed endothelial cell markers (40±2% CD34+, 9±2% FLK1+). 42±4% expressed myocyte markers (αMHC+, cTNT+). IF revealed a progenitor-like population with immature cell morphology and proliferation potential (ki67+). Cell cycle analysis showed an enrichment of αMHC+ EpoR+ cells in S and G2 phase (49±7%, n=3) as compared to the αMHC- EpoR- population (13±3%, n=3). Moreover, we tested the effect of Epo in the biology of these CPCs in vitro. At d14 we observed a two-fold increase of GATA4+ and cTnT+ cardiac cells in the co-cultures treated with Epo (n=3). CPC cycle arrest abrogated the aforementioned effects, suggesting that Epo influences mainly CPC proliferation. Finally, we tested the potential of Epo to protect against ischemia by inducing the proliferation of these αMHC+ CPCs in vivo in a myocardial infarction (MI) model. 4 weeks post MI, echocardiography did not reveal a significant functional improvement of the Epo receiving mice (2x, 2U/g Epo i.p). Nevertheless, FC analysis of the progenitor pool showed a significant augmentation of αMHC+ and cTnT+ cells (Sham: 19±3% vs Epo 35±3%, n=5; MI: 10.6±2.3%, n=6 vs Epo 20.3±1.9%, n=8). These data suggest an activation of myogenic progenitors by Epo, despite the lack of apparent regeneration under the investigated conditions. In conclusion, we found that EpoR is expressed in a putative cardiomyogenic progenitor cell pool in the adult heart. Epo drives their proliferation in vitro and in vivo even upon acute cardiac injury. We are currently investigating the long-term consequences of the observed progenitor cell activation in models of chronic ischemic injury.

The aim of this study was to compare clinical outcomes among unselected patients stratified in categories of body mass index, who underwent percutaneous coronary intervention (PCI) with either sirolimus-eluting or paclitaxel-eluting stents.Overweight and obesity are often considered risk factors for cardiovascular events. However, recent studies have associated obesity with better outcomes after PCI with bare-metal stents. Data from routine clinical practice using drug-eluting stents (DES) focusing on this "obesity paradox" are not available.We used data from DES.DE (German Drug-Eluting Stent) registry to compare in-hospital and 1-year outcomes among unselected patients undergoing PCI with DES implantation. Primary endpoints were the rate of major adverse cardiac and cerebrovascular events (MACCE) (defined as the composite of death, myocardial infarction, and stroke) and target vessel revascularization (TVR).Between October 2005 and 2006, 1,436 normal weight, 2,839 overweight, and 1,531 obese patients treated with DES were enrolled at 98 sites. Baseline clinical parameters were more severe in overweight and obese patients; 1-year follow-up comparison between groups revealed similar rates of all-cause death (3.3% vs. 2.4% vs. 2.4%; p=0.17), MACCE (7.1% vs. 5.6% vs. 5.5%; p=0.09), and TVR in survivors (10.9% vs. 11.7% vs. 11.6%; p=0.56) in normal weight individuals compared with overweight or obese patients. Such results persisted after risk-adjustment for heterogeneous baseline characteristics of groups and were independent of the types of DES.DES.DE revealed no evidence of "obesity paradox" in a routine clinical practice using DES.

Under acute or chronic stresses, the adult heart undergoes a remodeling process that involves cardiomyocyte hypertrophy accompanied by apoptosis, necrosis, and fibrosis that lead to impaired cardiac contractility. The role of endogenous regeneration in this process is currently under investigation. Sustained deleterious stimuli will lead to a decompensated form of hypertrophy often culminating in heart failure.1 This form of hypertrophy is often referred to as “maladaptive.” When dealing with hypertrophy, it appears important to distinguish between the term being used on the cellular and molecular level (enlargement of individual cardiomyocytes and re-expression of fetal/embryonic genes) and the organ level (increased heart weight, left ventricular wall thickness, and functional diastolic and systolic impairment). In our view, these processes are certainly linked but not identical. Hypertrophy on the organ levels summarizes several independent cellular and molecular processes (see below), where cardiomyocyte growth is not necessarily the most important. Independent of its origin, cardiac hypertrophy is associated with alterations in cardiac geometry, mass, architecture, and function controlled by a complex network of interconnected and abundant signal-transduction pathways.2 New signaling molecules are emerging as possible targets to specifically attenuate maladaptive hypertrophy. Pathological, stress-induced growth of cardiomyocytes was shown to depend on Wnt/β-catenin nuclear signaling rather than its adhesive function in cell adhesion. However, the specificity of the cell type and the molecular mechanisms governing the Wnt signaling–dependent changes are currently unknown.3 In this issue of the Hypertension , the study by Malekar et al4 provides new evidences concerning the …

Aims The transcription factor MEF2 is a downstream target for several hypertrophic signalling pathways in the heart, suggesting that MEF2 may act as a valuable therapeutic target in the treatment of heart failure. Methods and results In this study, we investigated the potential benefits of overall MEF2 inhibition in a mouse model of chronic pressure overloading, by subjecting transgenic mice expressing a dominant negative form of MEF2 (DN-MEF2 Tg) in the heart, to transverse aortic constriction (TAC). Histological analysis revealed no major differences in cardiac remodelling between DN-MEF2 Tg and control mice after TAC. Surprisingly, echocardiographic analysis revealed that DN-MEF2 Tg mice had a decrease in cardiac function compared with control animals. Analysis of the mitochondrial respiratory chain showed that DN-MEF2 Tg mice displayed lower expression of NADH dehydrogenase subunit 6 (ND6), part of mitochondrial Complex I. The reduced expression of ND6 in DN-MEF2 Tg mice after pressure overload correlated with an increase in cell death secondary to overproduction of reactive oxygen species (ROS). Conclusion Our data suggest that MEF2 transcriptional activity is required for mitochondrial function and its inhibition predisposes the heart to impaired mitochondrial function, overproduction of ROS, enhanced cell death, and cardiac dysfunction, following pressure overload.

Hypertension-induced renal and heart failure account for a large proportion of chronic disease burden in the elderly. Antihypertensive therapy may halt the progression of disease. Preventing organ damage has emerged as a primary target for new approaches to treat hypertension. Signaling pathways affected by hypertension but not necessarily involved in blood pressure regulation itself have been identified as attractive new targets. Already in the early 1960s, a cellular stopwatch was described, which induced a growth arrest of normal somatic cells after several rounds of cell division in culture. In contrast, cancer cells were found to proliferate unlimited, implicating cellular senescence as an important molecular mechanism of protection against cancer. The molecular and cellular pathways controlling senescence have since been identified. The 3 “Hayflick factors” recording the proliferative history of cells and tissues are telomere shortening, accumulation of damaged DNA plus chromosomal damage, as well as derepression of the INK4a/ARF genomic locus. The molecular pathways mediating senescence, namely, telomere shortening and expression of p16 INK4a through stress and aberrant signaling–induced senescence are dissociated, indicating independent pathways.1 On a cellular level, a picture is emerging that tissue senescence is not only about the differentiated cells having a limited life span but also, and possibly even more important, reduced regenerative …

The adult heart has a uniform cellular response to adapt to injury after infarct or increased wall stress in chronic hypertension: hypertrophy of adult cardiomyocytes increases muscle fiber mass while at the same time apoptosis of cardiomyocytes may lead to further loss of contractile mass. The existence and quantitative amount of endogenous cardiac regeneration is currently under intense dispute, no clear picture has yet emerged. Recently, cardiac precursor cells and the signaling pathways controlling their differentiation in the adult organ have come into focus. In heart development, beta-catenin was identified to play a biphasic role in cardiomyocyte differentiation. While initially WNT/beta-catenin activation is required to commit mesenchymal cells to the cardiac lineage, downregulation of beta-catenin is needed for cardiomyocyte differentiation at later stages. Recent genetic data published by our lab suggest beta-catenin downregulation to be beneficial for adult cardiac remodeling. Here we discuss these data in the context of beta-catenin's role in adult cardiomyocyte hypertrophy, apoptosis and possibly regeneration.