Temporary extracorporeal life support: single-centre experience with a new concept.

OBJECTIVES: The combination of veno-arterial extracorporeal membrane oxygenation with a micro-axial flow pump (ECMELLA) is increasingly used for cardiogenic shock (CS) therapy. We report our experience with a novel single-artery access ECMELLA setup with either femoral (2.0) or jugular venous cannulation (2.1), respectively. METHODS: Data from 67 consecutive CS patients treated with ECMELLA 2.0 (n = 56) and 2.1 (n = 11) from December 2020 and December 2022 in a tertiary cardiac center were retrospectively analyzed. RESULTS: The mean age was 60.7 ± 11 years, 56 patients (84%) were male. CS aetiology was acute on chronic heart failure (n = 35, 52%), myocardial infarction (n = 13, 19.5%), postcardiotomy syndrome (n = 16, 24%) and myocarditis (n = 3, 4.5%). Preoperatively 31 patients (46%) were resuscitated, 53 (79%) were on a ventilator and 60 (90%) were on inotropic support. The median vasoactive inotropic score was 32, and the mean arterial lactate was 8.1 mmol/l. In 39 patients (58%), veno-arterial extracorporeal membrane oxygenation was explanted after a median ECMELLA support of 4 days. Myocardial recovery was achieved in 18 patients (27%), transition to a durable left ventricular assist device in 16 (24%). Thirty-three patients (n = 33; 49%) died on support (25 on ECMELLA and 8 on Impella after de-escalation), 9 (13%) of whom were palliated. Axillary access site bleeding occurred in 9 patients (13.5%), upper limb ischaemia requiring surgical revision in 3 (4.5%). Axillary site infection occurred in 6 cases (9%), and perioperative stroke in 10 (15%; 6 hemorrhagic, 4 thromboembolic). CONCLUSIONS: ECMELLA 2.0/2.1 is a feasible and effective therapy for severe CS. The single-artery cannulation technique is associated with a relatively low rate of access-related complications.

Propensity score-based analysis of 30-day survival in cardiogenic shock patients supported with different microaxial left ventricular assist devices.

BACKGROUND AND METHODS: Microaxial left ventricular assist devices are used increasingly for treating cardiogenic shock. We compared the short-term outcome of patients supported with different microaxial devices for cardiogenic shock. A retrospective propensity score-adjusted analysis was performed in cardiogenic shock patients treated with either the Impella CP (n = 64) or the Impella 5.0/5.5 (n = 62) at two tertiary cardiac care centers between 1/14 and 12/19. RESULTS: Patients in the Impella CP group were significantly older (69.6 ± 10.7 vs. 58.7 ± 11.9 years, p = .001), more likely in INTERMACS profile 1 (76.6% vs. 50%, p = .003) and post-C-reactive protein (CPR) (36% vs. 13%, p = .006). The median support time was 2.0 days [0.0, 5.3] in the CP group vs. 8.5 days [4.3, 15.8] in the 5.0/5.5 group (p < .001). The unadjusted 30-day survival was significantly higher in the Impella 5.0/5.5 group (58% vs. 36%, p = .021, odds ratio [OR] for 30-day survival on Impella 5.0/5.5 was 3.68 [95% confidence interval [CI]: [1.46-9.90]], p = .0072). After adjustment, the 30-day survival was similar for both devices (OR: 1.23, 95% CI: [0.34-4.18], p = .744). Lactate levels above 8 mmol/L and preoperative CPR were associated with a significant mortality increase in both cohorts (OR: 10.7, 95% CI: [3.45-47.34], p < .001; OR: 13.2, 95% CI: [4.28-57.89], p < .001, respectively). CONCLUSION: Both Impella devices offer a similar effect with regard to survival in cardiogenic shock patients. Preoperative CPR or lactate levels exceeding 8 mmol/L immediately before implantation have a poor prognosis on Impella CP and Impella 5.0/5.5.

Myocarditis and inflammatory cardiomyopathy: current evidence and future directions.

Inflammatory cardiomyopathy, characterized by inflammatory cell infiltration into the myocardium and a high risk of deteriorating cardiac function, has a heterogeneous aetiology. Inflammatory cardiomyopathy is predominantly mediated by viral infection, but can also be induced by bacterial, protozoal or fungal infections as well as a wide variety of toxic substances and drugs and systemic immune-mediated diseases. Despite extensive research, inflammatory cardiomyopathy complicated by left ventricular dysfunction, heart failure or arrhythmia is associated with a poor prognosis. At present, the reason why some patients recover without residual myocardial injury whereas others develop dilated cardiomyopathy is unclear. The relative roles of the pathogen, host genomics and environmental factors in disease progression and healing are still under discussion, including which viruses are active inducers and which are only bystanders. As a consequence, treatment strategies are not well established. In this Review, we summarize and evaluate the available evidence on the pathogenesis, diagnosis and treatment of myocarditis and inflammatory cardiomyopathy, with a special focus on virus-induced and virus-associated myocarditis. Furthermore, we identify knowledge gaps, appraise the available experimental models and propose future directions for the field. The current knowledge and open questions regarding the cardiovascular effects associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are also discussed. This Review is the result of scientific cooperation of members of the Heart Failure Association of the ESC, the Heart Failure Society of America and the Japanese Heart Failure Society.

Prediction of survival of patients in cardiogenic shock treated by surgically implanted Impella 5+ short-term left ventricular assist device.

OBJECTIVES: Short-term mechanical circulatory support is a life-saving treatment for acute cardiogenic shock (CS). This multicentre study investigates the preoperative predictors of 30-day mortality in CS patients treated with Impella 5.0 and 5.5 short-term left ventricular assist devices. METHODS: Data of patients in CS (n = 70) treated with the Impella 5 (n = 63) and 5.5 (n = 7) in 2 centres in Berlin between October 2016 and October 2019 were collected retrospectively. RESULTS: CS was caused by acute myocardial infarction (n = 16), decompensated chronic heart failure (n = 41), postcardiotomy syndrome (n = 5) and acute myocarditis (n = 8). Before implantation 12 (17%) patients underwent cardiopulmonary resuscitation and 32 (46%) patients were ventilated. INTERMACS level 1, 2 and 3 was established in 35 (50%), 29 (41%) and 6 (9%) of patients, respectively. The mean preoperative lactate level was 4.05 mmol/l. The median support time was 7 days (IR= 4-15). In 18 cases, the pump was removed for myocardial recovery, in 22 cases, durable left ventricular assist devices were implanted, and 30 patients died on support. The overall 30-day survival was 51%. Statistical analysis showed that an increase in lactate per mmol/l [odds ratio (OR) 1.217; P = 0.015] and cardiopulmonary resuscitation before implantation (OR 16.74; P = 0.009) are predictors of 30-day survival. Based on these data, an algorithm for optimal short-term mechanical circulatory support selection is proposed. CONCLUSIONS: Impella treatment is feasible in severe CS. Severe organ dysfunction, as well as the level and duration of shock predict early mortality. An algorithm based on these parameters may help identify patients who would benefit from Impella 5+ support.

Modulation of the acute defence reaction by eplerenone prevents cardiac disease progression in viral myocarditis.

AIMS: Left ventricular (LV) dysfunction in viral myocarditis is attributed to myocardial inflammation and fibrosis, inducing acute and long-time cardiac damage. Interventions are not established. On the basis of the link between inflammation, fibrosis, aldosterone, and extracellular matrix regulation, we aimed to investigate the effect of an early intervention with the mineralocorticoid receptor antagonist (MRA) eplerenone on cardiac remodelling in a murine model of persistent coxsackievirus B3 (CVB3)-induced myocarditis. METHODS AND RESULTS: SWR/J mice were infected with 5 × 104 plaque-forming units of CVB3 (Nancy strain) and daily treated either with eplerenone (200 mg/kg body weight) or with placebo starting from Day 1. At Day 8 or 28 post infection, mice were haemodynamically characterized and subsequently sacrificed for immunohistological and molecular biology analyses. Eplerenone did not influence CVB3 load. Already at Day 8, 1.8-fold (P < 0.05), 1.4-fold (P < 0.05), 3.2-fold (P < 0.01), and 2.1-fold (P < 0.001) reduction in LV intercellular adhesion molecule 1 expression, presence of monocytes/macrophages, oxidative stress, and apoptosis, respectively, was observed in eplerenone-treated vs. untreated CVB3-infected mice. In vitro, eplerenone led to 1.4-fold (P < 0.01) and 1.2-fold (P < 0.01) less CVB3-induced cardiomyocyte oxidative stress and apoptosis. Furthermore, collagen production was 1.1-fold (P < 0.05) decreased in cardiac fibroblasts cultured with medium of eplerenone-treated vs. untreated CVB3-infected HL-1 cardiomyocytes. These ameliorations were in vivo translated into prevention of cardiac fibrosis, as shown by 1.4-fold (P < 0.01) and 2.1-fold (P < 0.001) lower collagen content in the LV of eplerenone-treated vs. untreated CVB3-infected mice at Days 8 and 28, respectively. This resulted in an early and long-lasting improvement of LV dimension and function, as indicated by reduced LV end-systolic volume and end-diastolic volume, and an increase in LV contractility (dP/dtmax ) and LV relaxation (dP/dtmin ), respectively (P < 0.05). CONCLUSIONS: Early intervention with the MRA eplerenone modulates the acute host and defence reaction and prevents cardiac disease progression in experimental CVB3-induced myocarditis without aggravation of viral load. The findings advocate for an initiation of therapy of viral myocarditis as early as possible, even before the onset of inflammation-induced myocardial dysfunction. This may also have implications for coronavirus disease-19 therapy.

Targeting CD20+ B-lymphocytes in inflammatory dilated cardiomyopathy with rituximab improves clinical course: a case series.

BACKGROUND: The aetiology of dilated cardiomyopathy (DCM) is highly heterogeneous including genetic and/or acquired (infective, toxic, immune, endocrine, and nutritional) factors. The major part of acquired DCM in developed countries is caused by either viral or autoimmune myocarditis. It is believed that the activation of the T-lymphocyte cell system is the major pathomechanism underlying autoimmune myocarditis and inflammatory DCM (DCMi). However, in the hearts of a subset of patients, a significant number of CD20+ B-lymphocytes can be detected too. Limited information exists on the role of B-cell-dependent mechanisms in the progression of DCMi. Particularly CD20+ B-lymphocytes, which can be targeted by anti-CD20+ B-lymphocytes antibodies or inhibitors, might contribute to the pathogenesis of myocardial damage beyond antibody production. CASE SUMMARY: Here, we present a case series of six patients with subacute and chronic endomyocardial biopsy-proven CD20+ B-lymphocyte-associated DCMi, where symptomatic heart failure therapy, with or without combined immunosuppressive therapy with steroid-based treatment regime, was insufficient to improve cardiac function. Five patients improved clinically several weeks after a standard infusion protocol with rituximab, a chimeric monoclonal antibody against the pan-B-cell surface molecule CD20. DISCUSSION: Our case series shows that CD20+ B-lymphocyte persistence can play a pathophysiologic role in a subset of DCMi patients and highlights the potential of targeting CD20+ B cells in patients with prominent CD20+ B-lymphocyte persistence.

Mode-of-action of the PROPELLA concept in fulminant myocarditis.

AIMS: Haemodynamic load induces cardiac remodelling via mechano-transduction pathways, which can further trigger inflammatory responses. We hypothesized that particularly in an inflammatory disorder such as myocarditis, a therapeutic strategy is required which, in addition to providing adequate circulatory support, unloads the left ventricle, decreases cardiac wall stress, and mitigates inflammatory responses. METHODS AND RESULTS: Axial flow pumps such as the Impella systems comply with these requirements. Here, we report a potential mode-of-action of prolonged Impella support (PROPELLA concept) in fulminant myocarditis, including a decrease in cardiac immune cell presence, and integrin α1, α5, α6, α10 and ß6 expression during unloading. CONCLUSION: PROPELLA may provide benefits beyond its primary function of mechanical circulatory support in the form of additional disease-altering effects, which may contribute to enhanced myocardial recovery/remission in patients with chronic fulminant myocarditis.

NOD2 (Nucleotide-Binding Oligomerization Domain 2) Is a Major Pathogenic Mediator of Coxsackievirus B3-Induced Myocarditis.

BACKGROUND: The cytoplasmatic pattern recognition receptor, NOD2 (nucleotide-binding oligomerization domain 2), belongs to the innate immune system and is among others responsible for the recognition of single-stranded RNA. With Coxsackievirus B3 (CVB3) being a single-stranded RNA virus, and the recent evidence that the NOD2 target, NLRP3 (NOD-like receptor family, pyrin domain containing 3) is of importance in the pathogenesis of CVB3-induced myocarditis, we aimed to unravel the role of NOD2 in CVB3-induced myocarditis. METHODS AND RESULTS: Endomyocardial biopsy NOD2 mRNA expression was higher in CVB3-positive patients compared with patients with myocarditis but without evidence of persistent CVB3 infection. Left ventricular NOD2 mRNA expression was also induced in CVB3-induced myocarditis versus healthy control mice. NOD2 knockdown(-/-) mice were rescued from the detrimental CVB3-mediated effects as shown by a reduced cardiac inflammation (less cardiac infiltrates and suppression of proinflammatory cytokines), cardiac fibrosis, apoptosis, lower CAR (Coxsackievirus and adenovirus receptor) expression and CVB3 copy number, and an improved left ventricular function in NOD2-/- CVB3 mice compared with wild-type CVB3 mice. In agreement, NOD2-/- decreased the CVB3-induced inflammatory response, CVB3 copy number, and apoptosis in vitro. NOD2-/- was further associated with a reduction in CVB3-induced NLRP3 expression and activity as evidenced by lower ASC (apoptosis-associated speck-like protein containing a CARD) expression, caspase 1 activity, or IL-1ß (interleukin-1ß) protein expression under in vivo and in vitro CVB3 conditions. CONCLUSIONS: NOD2 is an important mediator in the viral uptake and inflammatory response during the pathogenesis of CVB3 myocarditis.

Multimodality imaging approach in the diagnosis of chronic myocarditis with preserved left ventricular ejection fraction (MCpEF): The role of 2D speckle-tracking echocardiography.

BACKGROUND: Up to one third of patients with chronic myocarditis (MC) have preserved left ventricular (LV) ejection fraction (MCpEF). The purpose of this study was to evaluate the role of adding 2D speckle-tracking echocardiography (STE) to cardiac magnetic resonance imaging (cMRI) in the diagnosis of patients with MCpEF. METHODS AND RESULTS: We analyzed 67 patients with suspected MCpEF who underwent endomyocardial biopsy (EMB). Thirty-two patients with confirmed chronic myocardial inflammation by EMB served as study group (MCpEF) and the remaining patients (n=35) served as control group. In all patients, 2D STE and cMRI were performed within 48h before EMB. Patients with MCpEF had significantly lower LV global longitudinal systolic strain (GLS) than controls (GLS: -17.01±2.42% vs. -19.39±3.81%, p<0.001; respectively). In line, an abnormal GLS had adequate diagnostic performance to detect MCpEF (sensitivity, specificity, and accuracy of 82%, 70%, and 76%, respectively), which was superior to cMRI based on the Lake-Louise criteria (sensitivity, specificity, and accuracy 54%, 71%, and 67%, respectively). In addition, adding GLS to the Lake-Louise criteria improved significantly the diagnostic performance of cMRI to detect MCpEF (sensitivity, specificity, and accuracy 96%, 55%, and 75%, respectively). CONCLUSION: The findings of this study suggest that GLS using 2D STE could play an important role in the diagnostic evaluation of patients with suspected chronic myocarditis with preserved LV ejection fraction (MCpEF).

Postprocedural radial artery occlusion rate using a sheathless guiding catheter for left ventricular endomyocardial biopsy performed by transradial approach.

BACKGROUND: For coronary interventions the arterial access via the radial artery is associated with fewer vascular access site complications, and has been shown to reduce major bleeding when compared to the femoral approach. But the endomyocardial biopsy (EMB) approach is usually done by a transfemoral or cervical access known to be associated with an increased risk of artery puncture and its potential complications (i.e., false aneurysm, artery-venous fistula) and needs post-procedural immobilization. A transradial approach for EMBs is not standardized. The aim of our study is to validate safety and efficacy of the transradial access approach for left ventricular EMB, and to define patients eligible for a safe and successful procedure. METHODS AND RESULTS: We evaluated the transradial access using a 7.5 F sheathless multipurpose guiding catheter to obtain EMBs from the left ventricle (LV). 18 patients were included. The transradial success rate was 100% (18/18). There were no periprocedural cardiac complications. Immediate post-procedural ambulation could be achieved in all patients. Although radial artery pulse was confirmed by ultrasonic vascular Doppler after removal of the guide in 100% (18/18) of the patients, 50% (9/18) of the patients showed occlusion of the radial artery RAO) by duplex sonography proximal to the access site. 33% (3/9) of the patients in the RAO group and 11,1% (1/9) of the patients in the patent radial artery (RAP) group, respectively, experienced mild pain after the procedure in the right lower arm. Colour Doppler ultrasonography of the right radial artery performed 24 h after the procedure revealed radial occlusion in 50% (9/18) of the patients. The diameter of the radial artery was significantly smaller in the RAO group (p = 0,034), peak systolic velocity (PSV) of the right ulnar artery was significantly higher in the RAO group (p = 0.012). Peak systolic velocity of the opposite radial artery was significantly lower in the RAO group (p = 0,045). Gender, sex, diabetes, radial artery inner diameter ≤2.5 mm and lower peak systolic velocity of < 50 cm/s are predictors of RAO. CONCLUSION: The present study demonstrates the safety and efficacy of a transradial access for EMB using a highly hydrophilic sheathless guiding catheter.

Apolipoprotein A-I gene transfer exerts immunomodulatory effects and reduces vascular inflammation and fibrosis in ob/ob mice.

BACKGROUND: Obesity is associated with vascular inflammation, fibrosis and reduced high-density lipoproteins (HDL)-cholesterol. We aimed to investigate whether adenoviral gene transfer with human apolipoprotein (apo) A-I (Ad.A-I), the main apo of HDL, could exert immunomodulatory effects and counteract vascular inflammation and fibrosis in ob/ob mice. METHODS: Ad.A-I transfer was performed in 8 weeks (w) old ob/ob mice, which were sacrificed 7 w later. The aorta was excised for mRNA analysis and the spleen for splenocyte isolation for subsequent flow cytometry and co-culture with murine fibroblasts. HDL was added to mononuclear cells (MNC) and fibroblasts to assess their impact on adhesion capacity and collagen deposition, respectively. RESULTS: Ad.A-I led to a 1.8-fold (p < 0.05) increase in HDL-cholesterol versus control ob/ob mice at the day of sacrifice, which was paralleled by a decrease in aortic TNF-α and VCAM-1 mRNA expression. Pre-culture of MNC with HDL decreased their adhesion to TNF-α-activated HAEC. Ad.A-I exerted immunomodulatory effects as evidenced by a downregulation of aortic NOD2 and NLRP3 mRNA expression and by a 12 %, 6.9 %, and 15 % decrease of the induced proliferation/activity of total splenic MNC, CD4+, and CD8+ cells in ob/ob Ad.A-I versus control ob/ob mice, respectively (p < 0.05). Ad.A-I further reduced aortic collagen I and III mRNA expression by 62 % and 66 %, respectively (p < 0.0005), and abrogated the potential of ob/ob splenocytes to induce the collagen content in murine fibroblasts upon co-culture. Finally, HDL decreased the TGF-ß1-induced collagen deposition of murine fibroblasts in vitro. CONCLUSIONS: Apo A-I transfer counteracts vascular inflammation and fibrosis in ob/ob mice.

Human Endomyocardial Biopsy Specimen-Derived Stromal Cells Modulate Angiotensin II-Induced Cardiac Remodeling.

: Cardiac-derived adherent proliferating cells (CardAPs) are cells derived from human endomyocardial biopsy specimens; they share several properties with mesenchymal stromal cells. The aims of this study were to evaluate whether intramyocardial injection of CardAPs modulates cardiac fibrosis and hypertrophy in a mouse model of angiotensin II (Ang II)-induced systolic heart failure and to analyze underlying mechanisms. Intramyocardial application of 200,000 CardAPs improved left ventricular function. This was paralleled by a decline in left ventricular remodeling, as indicated by a reduction in cardiac fibrosis and hypertrophy. CardAPs reduced the ratio of the left ventricle to body weight and cardiac myosin expression (heavy chain), and decreased the Ang II-induced phosphorylation state of the cardiomyocyte hypertrophy mediators Akt, extracellular-signal regulated kinase (ERK) 1, and ERK2. In accordance with the antifibrotic and antihypertrophic effects of CardAPs shown in vivo, CardAP supplementation with cardiac fibroblasts decreased the Ang II-induced reactive oxygen species production, α-SMA expression, fibroblast proliferation, and collagen production. Coculture of CardAPs with HL-1 cardiomyocytes downregulated the Ang II-induced expression of myosin in HL-1. All antifibrotic and antihypertrophic features of CardAPs were mediated in a nitric oxide- and interleukin (IL)-10-dependent manner. Moreover, CardAPs induced a systemic immunomodulation, as indicated by a decrease in the activity of splenic mononuclear cells and an increase in splenic CD4CD25FoxP3, CD4-IL-10, and CD8-IL-10 T-regulatory cells in Ang II mice. Concomitantly, splenocytes from Ang II CardAPs mice induced less collagen in fibroblasts compared with splenocytes from Ang II mice. We conclude that CardAPs improve Ang II-induced cardiac remodeling involving antifibrotic and antihypertrophic effects via paracrine actions and immunomodulatory properties. SIGNIFICANCE: Despite effective pharmacological treatment with angiotensin II type I receptor antagonists or angiotensin II-converting enzyme inhibitors, morbidity and mortality associated with heart failure are still substantial, prompting the search of novel therapeutic strategies. There is accumulating evidence supporting the use of cell therapy for cardiac repair. This study demonstrates that cells derived from human endomyocardial biopsies, cardiac-derived adherent proliferating cells (CardAPs), have the potential to reduce angiotensin II-induced cardiac remodeling and improve left ventricular function in angiotensin II mice. The mechanism involves antifibrotic and antihypertrophic effects via paracrine actions and immunomodulatory properties. These findings support the potential of CardAPs for the treatment of heart failure.

Impaired Endothelial Regeneration Through Human Parvovirus B19-Infected Circulating Angiogenic Cells in Patients With Cardiomyopathy.

Human parvovirus B19 (B19V) is a common pathogen in microvascular disease and cardiomyopathy, owing to infection of endothelial cells. B19V replication, however, is almost restricted to erythroid progenitor cells (ErPCs). Endothelial regeneration attributable to bone marrow-derived circulating angiogenic cells (CACs) is a prerequisite for organ function. Because of many similarities of ErPCs and CACs, we hypothesized that B19V is a perpetrator of impaired endogenous endothelial regeneration. B19V DNA and messenger RNA from endomyocardial biopsy specimens, bone marrow specimens, and circulating progenitor cells were quantified by polymerase chain reaction analysis. The highest B19V DNA concentrations were found in CD34(+)KDR(+) cells from 17 patients with chronic B19V-associated cardiomyopathy. B19V replication intermediates could be detected in nearly half of the patients. Furthermore, chronic B19V infection was associated with impaired endothelial regenerative capacity. B19V infection of CACs in vitro resulted in expression of transcripts encoding B19V proteins. The capsid protein VP1 was identified as a novel inducer of apoptosis, as were nonstructural proteins. Inhibition studies identified so-called death receptor signaling with activation of caspase-8 and caspase-10 to be responsible for apoptosis induction. B19V causally impaired endothelial regeneration with spreading of B19V in CACs in an animal model in vivo. We thus conclude that B19V infection and damage to CACs result in dysfunctional endogenous vascular repair, supporting the emergence of primary bone marrow disease with secondary end-organ damage.

LXR agonism improves TNF-α-induced endothelial dysfunction in the absence of its cholesterol-modulating effects.

Stimulation of the liver X receptor (LXR) is associated with anti-inflammatory and vascular-protective effects under hyperlipemic conditions. We examined whether LXR stimulation influences TNF-α-induced endothelial dysfunction under normolipemic conditions. Endothelium-dependent vasorelaxation of aortic rings was determined in an organ water bath. Human umbilical vein endothelial cells (HUVEC) were exposed to TNF-α (10 ng/ml) in the presence or absence of 5 µM of the LXR agonist T0901317 or GW3965 and changes in TNF-α-induced endothelial cell apoptosis, inflammation, oxidative stress, and NO metabolism were analyzed. T0901317 improved TNF-α-impaired endothelium-dependent relaxation of aortic rings in response to acetylcholine. T0901317 decreased the TNF-α-induced apoptosis and inflammation as indicated by a decrease in caspase 3/7 activity, VCAM-1 mRNA expression and subsequent mononuclear cell adhesion. Furthermore, T0901317 reduced the expression of the oxidative stress markers: AT1R, NOX4, and p22phox and normalized the TNF-α-induced NOX activity to basal levels. In line with the reduced AT1R expression, T0901317 impaired the Ang II responsiveness. T0901317 influenced NO metabolism as indicated by a decrease in TNF-α-upregulated arginase activity, a reversal of TNF-α-induced downregulation of argininosuccinate synthase mRNA expression and eNOS expression to basal levels and a raise in NO production. Furthermore, T0901317 decreased the TNF-α-induced superoxide and nitrotyrosine production, but did not upregulate the TNF-α-downregulated eNOS dimer/monomer ratio. Silencing of LXRß, but not of LXRα, abrogated the anti-apoptotic effects of T0901317. We conclude that LXR agonism improves TNF-α-impaired endothelial function via its anti-apoptotic, anti-inflammatory, and anti-oxidative properties and its capacity to restore TNF-α-impaired NO bioavailability independent of its cholesterol-modulating effects.

Nerve growth factor promotes cardiac repair following myocardial infarction.

RATIONALE: Nerve growth factor (NGF) promotes angiogenesis and cardiomyocyte survival, which are both desirable for postinfarction myocardial healing. Nonetheless, the NGF potential for cardiac repair has never been investigated. OBJECTIVE: To define expression and localization of NGF and its high-affinity receptor TrkA (tropomyosin-related receptor A) in the human infarcted heart and to investigate the cardiac roles of both endogenous and engineered NGF using a mouse model of myocardial infarction (MI). METHODS AND RESULTS: Immunostaining for NGF and TrkA was performed on heart samples from humans deceased of MI or unrelated pathologies. To study the post-MI functions of endogenous NGF, a NGF-neutralizing antibody (Ab-NGF) or nonimmune IgG (control) was given to MI mice. To investigate the NGF therapeutic potential, human NGF gene or control (empty vector) was delivered to the murine periinfarct myocardium. Results indicate that NGF is present in the infarcted human heart. Both cardiomyocytes and endothelial cells (ECs) possess TrkA, which suggests NGF cardiovascular actions in humans. In MI mice, Ab-NGF abrogated native reparative angiogenesis, increased EC and cardiomyocyte apoptosis and worsened cardiac function. Conversely, NGF gene transfer ameliorated EC and cardiomyocyte survival, promoted neovascularization and improved myocardial blood flow and cardiac function. The prosurvival/proangiogenic Akt/Foxo pathway mediated the therapeutic benefits of NGF transfer. Moreover, NGF overexpression increased stem cell factor (the c-kit receptor ligand) expression, which translated in higher myocardial abundance of c-kit(pos) progenitor cells in NGF-engineered hearts. CONCLUSIONS: NGF elicits pleiotropic beneficial actions in the post-MI heart. NGF should be considered as a candidate for therapeutic cardiac regeneration.

Attenuation of left ventricular dysfunction by an ACE inhibitor after myocardial infarction in a kininogen-deficient rat model.

Bradykinin (BK) coronary outflow and left ventricular (LV) performance of kininogen-deficient Brown Norway Katholiek (BNK) rats and Brown Norway Hannover (BNH) controls were investigated. We analyzed whether the angiotensin-converting enzyme (ACE) inhibitor ramipril is able to attenuate LV dysfunction after induction of myocardial infarction (MI) in this animal model. Ex vivo, the basal BK content in the coronary outflow of buffer-perfused, isolated hearts was measured by specific radioimmunoassay. In vivo, left ventricular pressure (LVP), the maximal rate of LVP increase, LV end-diastolic pressure, the maximal rate of LVP decrease and heart rate were determined using a tip catheter 3 weeks after induction of MI. Compared to BNK rats, basal BK outflow was increased 30-fold in controls (p<0.01). In vivo, we found no significant differences between sham-ligated BNK and BNH rats in basal LV function. After MI, the impairment of LV function was significantly worse in BNK rats when compared to BNH rats. ACE inhibition significantly attenuated this LV dysfunction in both groups, when compared to untreated animals. Reduced basal BK level resulting from kininogen deficiency has no effect on basal LV function, but remains to be a risk factor for the ischemic heart. However, ACE inhibition is sufficient to improve LV function despite kininogen deficiency.

The angiotensin-(1-7) receptor agonist AVE0991 is cardioprotective in diabetic rats.

Angiotensin-(1-7) is associated with beneficial effects in cardiovascular diseases. In this study, we determined the effect of AVE0991, a nonpeptide angiotensin-(1-7) receptor agonist, on cardiac function in an animal model of diabetes mellitus type I. Diabetes was induced in Sprague-Dawley rats by a single injection of streptozotocin (70 mg/kg). Diabetic and non-diabetic animals were fed with AVE0991 (20 mg/kg per day) or control chow. Normoglycemic control chow- or AVE0991-fed rats served as controls (n=10/group). After five weeks, metabolic cage experiments were performed to assess metabolic parameters. Six weeks after induction of diabetes, cardiac function was monitored using a Millar-tip catheter system. AVE0991 had no effect on any of the investigated hemodynamic parameters under normoglycemic conditions. Hyperglycemia was comparable in diabetic animals with or without AVE0991 treatment. Diabetic control rats suffered from severe systolic dysfunction, indicated by a significant decrease in heart rate, left ventricular systolic pressure, systolic blood pressure and an impairment of left ventricular contractility. Administration of AVE0991 clearly rescued cardiac function under diabetic conditions as indicated by a normalisation of blood pressure and contractility parameters. Our data demonstrates a dominant beneficial impact of AVE0991 on the diabetic heart, implying a cardioprotective role for angiotensin-(1-7) under hyperglycemic conditions and thus pointing to new therapeutic strategies using angiotensin-(1-7) agonists to treat cardiovascular complications in diabetes mellitus.

Human adult skeletal muscle stem cells differentiate into cardiomyocyte phenotype in vitro.

Cell transplantation to repair or regenerate injured myocardium is a new frontier in the treatment of cardiovascular disease. Most studies on stem cell transplantation therapy in both experimental heart infarct and in phase-I human clinical trials have focused on the use of undifferentiated stem cells. Based on our previous observations demonstrating the presence of multipotent progenitor cells in human adult skeletal muscle, in this study we investigated the capacity of these progenitors to differentiate into cardiomyocytes. Here we show an efficient protocol for the cardiomyogenic differentiation of human adult skeletal muscle stem cells in vitro. We found that treatment with Retinoic Acid directed cardiomyogenic differentiation of skeletal muscle stem cells in vitro. After Retinoic Acid treatment, cells expressed cardiomyocyte markers and acquired spontaneous contraction. Functional assays exhibited cardiac-like response to increased extracellular calcium. When cocultured with mouse cardiomyocytes, Retinoic Acid-treated skeletal muscle stem cells expressed connexin43 and when transplanted into ischemic heart were detectable even 5 weeks after injection. Based on these results, we can conclude that human adult skeletal muscle stem cells, if opportunely treated, can transdifferentiate into cells of cardiac lineage and once injected into infarcted heart can integrate, survive in cardiac tissue and improve the cardiac function.

Tumor necrosis factor-alpha antagonism protects from myocardial inflammation and fibrosis in experimental diabetic cardiomyopathy.

To investigate the effect of anti-cytokine-based therapy in the course of diabetic cardiomyopathy, we performed a study using an anti-TNF-alpha monoclonal antibody treatment (mab) in Sprague male Dawley (SD) rats with streptozotocin-induced diabetic cardiomyopathy. Five days after streptozotocin injection, rats were treated with the anti-TNF-alpha mAb C432A for 6 weeks.At the end of the study, left ventricular (LV) function was determined by a pressure-catheter. Intercellular adhesion molecule (ICAM)-1, vascular adhesion molecule (VCAM)-1, beta2-lymphocyte-integrins(+) (CD18(+), CD11a(+), CD11b(+)), ED1/CD68(+) and cytokine (TNF-alpha, interleukin (IL)-1beta)- expressing infiltrates, total collagen content and stainings of collagen I and III were quantified by digital image analysis. LV phosphorylated and total ERK protein levels were determined by Western Blot. TNFalpha-antagonism reduced ICAM-1- and VCAM-1 expression and leukocyte infiltration to levels of non-diabetics and decreased macrophage residence by 3.3-fold compared with untreated diabetics. In addition, anti-TNF-alpha mAb-treatment decreased diabetes-induced cardiac TNF-alpha and IL-1beta expression by 2.0-fold and 1.8- fold, respectively, and reduced the ratio of phosphorylated to total ERK by 2.7-fold. The reduction in intramyocardial inflammation was associated with a 5.4-fold and 3.6-fold reduction in cardiac collagen I and III content, respectively. This was reflected by a normalization of cardiac total collagen content to levels of non-diabetics and associated with an improved LV function. TNFalpha-antagonism attenuates the development of experimental diabetic cardiomyopathy associated with a reduction of intramyocardial inflammation and cardiac fibrosis.

Regional and global protective effects of tissue kallikrein gene delivery to the peri-infarct myocardium.

BACKGROUND: The kallikrein-kinin system participates in the maintenance of the cardiovascular phenotype. We previously demonstrated that human tissue kallikrein gene (hTK) transfer promotes the healing of ischemic limbs. The present investigation aimed to test the original hypothesis that hTK delivery to the peri-infarct myocardium would prevent post-ischemic heart failure. METHODS AND RESULTS: Myocardial infarction (MI) was induced in anesthetized mice by permanently occluding the left coronary descendant. hTK was delivered to the peri-infarct myocardium via an adenoviral vector (Ad.hTK). Controls received Ad.Null or saline. Survival rate was similar among groups. Ad.hTK increased the number of circulating endothelial progenitor cells and promoted the growth of capillaries and arterioles in the peri-infarct myocardium. In addition, Ad.hTK increased the abundance of cardiac progenitor cells (CPCs) in the peri-infarct and suppressed the apoptotic death of peri-infarct cardiomyocytes in vivo and ex vivo. As a consequence of these beneficial effects, at 5 weeks from MI, hTK-transduced hearts were protected from post-MI ventricular dilatation and showed better systolic and diastolic functions. CONCLUSIONS: Ad.hTK benefits the neovascularization and viability of peri-infarct myocardium and increases CPC abundance, thereby decreasing ventricular dysfunction. Our study significantly adds to the knowledge of the protective effects of TK gene transfer on ischemic diseases and opens new avenues for the treatment of post-MI cardiac failure.