ABSTRACT
Heart failure (HF) prevalence is rising due to reduced early mortality and demographic change. Relaxin (RLN) mediates protective effects in the cardiovascular system through Relaxin-receptor 1 (RXFP1). Cardiac overexpression of RXFP1 with additional RLN supplementation attenuated HF in the pressure-overload transverse aortic constriction (TAC) model. Here, we hypothesized that robust transgenic RXFP1 overexpression in cardiomyocytes (CM) protects from TAC-induced HF even in the absence of RLN. Hence, transgenic mice with a CM-specific overexpression of human RXFP1 (hRXFP1tg) were generated. Receptor functionality was demonstrated by in vivo hemodynamics, where the administration of RLN induced positive inotropy strictly in hRXFP1tg. An increase in phospholamban-phosphorylation at serine 16 was identified as a molecular correlate. hRXFP1tg were protected from TAC without additional RLN administration, presenting not only less decline in systolic left ventricular (LV) function but also abrogated LV dilation and pulmonary congestion compared to WT mice. Molecularly, transgenic hearts exhibited not only a significantly attenuated fetal and fibrotic gene activation but also demonstrated less fibrotic tissue and CM hypertrophy in histological sections. These protective effects were evident in both sexes. Similar cardioprotective effects of hRXFP1tg were detectable in a RLN-knockout model, suggesting an alternative mechanism of receptor activation through intrinsic activity, alternative endogenous ligands or crosstalk with other receptors. In summary, CM-specific RXFP1 overexpression provides protection against TAC even in the absence of endogenous RLN. This suggests RXFP1 overexpression as a potential therapeutic approach for HF, offering baseline protection with optional RLN supplementation for specific activation.
Subject(s)
Myocytes, Cardiac , Receptors, G-Protein-Coupled , Receptors, Peptide , Relaxin , Animals , Humans , Male , Mice , Heart Failure/metabolism , Heart Failure/prevention & control , Heart Failure/genetics , Mice, Inbred C57BL , Mice, Transgenic , Myocytes, Cardiac/metabolism , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Receptors, Peptide/genetics , Receptors, Peptide/metabolism , Relaxin/genetics , Relaxin/metabolismABSTRACT
Cardiovascular magnetic resonance imaging is one of the most important diagnostic modalities in the evaluation of cardiomyopathies. However, significant limitations are the complex and time-consuming workflows and the need of contrast agents. The aim of this multi-center retrospective study was to assess workflows and diagnostic value of a short, contrast agent-free cardiac magnetic resonance protocol. 160 patients from Heidelberg, Germany and 119 patients from Montreal, Canada with suspected cardiomyopathy and 20 healthy volunteers have been enrolled. Scans were performed at a 1.5Tesla or 3Tesla scanner in Heidelberg and at a 3Tesla scanner in Montreal. We used single-slice T1 map only. A stepwise analysis of images has been performed. The possible differential diagnosis after each step has been defined. T1-values and color-encoded T1 maps significantly contributed to the differential diagnosis in 54% of the cases (161/299); the final diagnosis has been done without late gadolinium enhancement images in 83% of healthy individuals, in 99% of patients with dilated cardiomyopathy, in 93% of amyloidosis patients, in 94% of patients with hypertrophic cardiomyopathy and in 85% of patients with hypertensive heart disease, respectively. Comparing the scan time with (48 ± 7 min) vs. without contrast agent (23 ± 5 min), significant time saving could be reached by the short protocol. Subgroup analysis showed the most additional diagnostic value of T1 maps in amyloidosis and hypertrophic cardiomyopathy or in confirmation of normal findings. In patients with unclear left ventricular hypertrophy, a short, non-contrast protocol can be used for diagnostic decision-making, if the quality of the T1 map is diagnostic, even if only one slice is available.
ABSTRACT
Lentiviral modification of hematopoietic stem cells (HSCs) paved the way for in vivo experimentation and therapeutic approaches in patients with genetic disease. A disadvantage of this method is the use of a ubiquitous promoter leads not only to genetic modification of the leukocyte subset of interest e.g. T-cells, but also all other subsequent leukocyte progeny of the parent HSCs. To overcome this limitation we tested a bicistronic lentivirus, enabling subset specific modifications. Designed novel lentiviral constructs harbor a global promoter (mPGK) regulating mCherry for HSCs selection and a T-cell specific promoter upstream of eGFP. Two T-cell specific promoters were assessed: the distal Lck-(dLck) and the CD3δ-promoter. Transduced HSCs were FACS sorted by mCherry expression and transferred into sublethally irradiated C57/BL6 mice. Successful transplantation and T-cell specific expression of eGFP was monitored by peripheral blood assessment. Furthermore, recruitment response of lentiviral engineered leukocytes to the site of inflammation was tested in a peritonitis model without functional impairment. Our constructed lentivirus enables fast generation of subset specific leukocyte transgenesis as shown in T-cells in vivo and opens new opportunities to modify other HSCs derived subsets in the future.
Subject(s)
Hematopoietic Stem Cells/virology , Lentivirus Infections/virology , Lentivirus/genetics , T-Lymphocyte Subsets/physiology , T-Lymphocyte Subsets/virology , Animals , CD3 Complex/genetics , Cell Line, Tumor , Gene Transfer Techniques , Genetic Engineering/methods , Genetic Vectors/genetics , Green Fluorescent Proteins/genetics , Hematopoietic Stem Cell Transplantation/methods , Inflammation/genetics , Inflammation/virology , Leukocytes/physiology , Leukocytes/virology , Luminescent Proteins/genetics , Mice , Mice, Inbred C57BL , Promoter Regions, Genetic/geneticsABSTRACT
BACKGROUND: Evidence on disease-related quality of life (DRQoL) of patients with implantable cardioverter-defibrillators (ICDs) has been described heterogeneously. Disease-specific measures of DRQoL in ICD patients are lacking. OBJECTIVES: The aim of this study was to gain a broader understanding of long-term DRQoL in ICD patients. Special focus was placed on stressors and cognitive management strategies in everyday life. METHODS: Data assessment was performed via semistructured, guideline-based interviews. The monocentric qualitative study included 10 ICD patients with primary and secondary prophylactic indication and 3 cardiologists. The qualitative analysis used the salutogenesis model (Antonovsky) as a framework. RESULTS: The interviews show that most patients do not experience a prominent limitation in their quality of life through the ICD. We found that patients focus on their individual coping strategies to handle the ICD indication with a sense of coherence, aiming at understanding their situation and giving it meaning. Whether the DRQoL is modified positively or negatively after ICD implantation depends on individual factors of resilience and factors of coherence. CONCLUSIONS: We established a salutogenic model for the assessment of DRQoL in patients with ICDs. A stable DRQoL on ICD implantation and follow-up could be achieved if patients at high risk (small sense of coherence and reduced resilience) are identified and their individual lifestyles are taken into account.
Subject(s)
Defibrillators, Implantable , Sense of Coherence , Electric Countershock , Humans , Quality of LifeABSTRACT
Atrial fibrillation (AF) is the most common form of cardiac tachyarrhythmia. It is estimated that in the Rhein-Neckar region approximately 40,000-50,000 out of 2â¯million people are affected. Due to demographic changes in the near future there will be a significant increase in the prevalence of AF within the next decades. The ARENA project was initiated by the Foundation Institute for Cardiac Infarction Research (IHF) Ludwigshafen in cooperation with cardiological and neurological departments of neighboring hospitals, resident doctors and pharmacies to improve the awareness and care of patients with AF. The particular aim is the prevention of stroke as one of the most dreaded complications. The project focusses on the following three subtopics: interventions, medication, migration. The aim of the intervention project is to raise awareness of AF as a risk factor for stroke and to improve the diagnostic work-up and care for patients with diagnosed or unknown AF. The subproject medication focusses on the adherence of patients with AF to the prescribed antithrombotic medication. To evaluate differences concerning patients with and without a migration background the subproject migration was initiated.
Subject(s)
Atrial Fibrillation , Stroke , Anthraquinones , Anticoagulants , Atrial Fibrillation/diagnosis , Atrial Fibrillation/drug therapy , Atrial Fibrillation/epidemiology , Humans , Registries , Risk Factors , Stroke/epidemiology , Stroke/prevention & controlABSTRACT
BACKGROUND: Risk stratification of older patients in the emergency department (ED) is seen as a promising and efficient solution for handling the increase in demand for geriatric emergency medicine. Previously, the predictive validity of commonly used tools for risk stratification, such as the identification of seniors at risk (ISAR), have found only limited evidence in German geriatric patient samples. Given that the adverse outcomes in question, such as rehospitalization, nursing home admission and mortality, are substantially associated with cognitive impairment, the potential of the short portable mental status questionnaire (SPMSQ) as a tool for risk stratification of older ED patients was investigated. OBJECTIVE: To estimate the predictive validity of the SPMSQ for a composite endpoint of adverse events (e.g. rehospitalization, nursing home admission and mortality). METHOD: This was a prospective cohort study with 260 patients aged 70 years and above, recruited in a cardiology ED. Patients with a likely life-expectancy below 24â¯h were excluded. Follow-up examinations were conducted at 1, 3, 6 and 12 month(s) after recruitment. RESULTS: The SPMSQ was found to be a significant predictor of adverse outcomes not at 1 month (area under the curve, AUC 0.55, 95% confidence interval, CI 0.46-0.63) but at 3 months (AUC 0.61, 95% CI 0.54-0.68), 6 months (AUC 0.63, 95% CI 0.56-0.70) and 12 months (AUC 0.63, 95% CI 0.56-0.70) after initial contact. CONCLUSION: For longer periods of observation the SPMSQ can be a predictor of a composite endpoint of adverse outcomes even when controlled for a range of confounders. Its characteristics, specifically the low sensitivity, make it unsuitable as an accurate risk stratification tool on its own.
Subject(s)
Emergency Service, Hospital/statistics & numerical data , Geriatric Assessment , Mass Screening/methods , Patient Admission/statistics & numerical data , Risk Assessment/methods , Aged , Critical Care , Female , Health Services for the Aged , Hospitalization , Humans , Male , Patient Discharge/statistics & numerical data , Prospective Studies , Risk Assessment/standardsABSTRACT
Cardiac biomarkers are an integral component of the diagnostic work-up of patients with suspected acute coronary syndrome (ACS). Cardiac troponin (cTn) is the most sensitive diagnostic biomarker for patients with ACS and enables the differentiation of acute non-ST-elevation myocardial infarction (NSTEMI) from unstable angina. All cardiac and non-cardiac differential diagnoses must be taken into consideration. The use of cTn has a prognostic value in a multitude of acute and chronic diseases apart from ACS. Highly sensitive cTn (hsTn) assays should be preferentially used. Point-of-care (POC) troponin assays can be used for rule-in of acute MI but are generally not useful for rule-out of MI due to their lack of sensitivity compared to hsTn assays. This, however, may change with recent developments of newer and improved POC troponin assays. For exclusion of MI using hsTn assays, there are various protocols available, such as the instant rule-out with undetectable hsTn levels at admission or normal hsTn/cTn levels combined with normal copeptin levels or rule-out with serial controls of hsTn after 1, 2 or 3â¯h. This article provides an overview of guideline-recommended rule-out protocols for patients with suspected ACS and discusses recent advances in POC troponin assays.
Subject(s)
Acute Coronary Syndrome/diagnosis , Biomarkers/blood , Chest Pain/etiology , Myocardial Infarction/diagnosis , Troponin/blood , Acute Coronary Syndrome/blood , Glycopeptides/blood , Humans , Myocardial Infarction/blood , Point-of-Care Testing , PrognosisABSTRACT
AIM: To compare right ventricular (RV) volumetry using state-of-the-art three-dimensional (3D) transthoracic echocardiography (3DE) and cardiac magnetic resonance imaging (CMR) near-simultaneously in a clinical setting. MATERIALS AND METHODS: Forty-seven consecutive patients received comprehensive echocardiography including 3DE within 30 minutes of CMR. RV volumetry was performed offline with semi-automated 3D endocardial border tracing as well as manual delineation of the compacted myocardium in short-axis views by CMR. RESULTS: Forty-two examinations (89%) could be analysed offline by 3D RV reconstruction. Mean RV volumes assessed by CMR and 3DE were 215±63 and 127±42 ml for end-diastole (RV-EDV), as well as 110±43 and 62±27 ml for end-systole (RV-ESV). RV-EDV, RV-ESV, and RV stroke volume measured by 3DE were significantly lower than RV volumetry by CMR. Mean bias were -88, -48, and -41 ml, respectively. Mean RV ejection fraction (-EF) showed a non-significant deviation of +2% between 3DE and CMR and the correlation coefficient was r=0.58 for RV-EF. CONCLUSION: RV-EF can be assessed reliably using transthoracic 3DE in patients with good image quality; however, absolute RV volumes measured by 3DE show a systematic deviation to CMR volumetry that has been previously neglected and requires careful interpretation regarding anatomical cardiac imaging.
Subject(s)
Echocardiography/methods , Heart Ventricles/diagnostic imaging , Heart Ventricles/pathology , Imaging, Three-Dimensional/methods , Magnetic Resonance Imaging/methods , Female , Humans , Image Interpretation, Computer-Assisted , Male , Middle Aged , Multimodal Imaging/methods , Organ Size , Prospective Studies , Reproducibility of ResultsABSTRACT
This article presents the case of a 22-year-old male patient with cardiomyopathy associated with a long history of methamphetamine abuse. Echocardiography revealed a dilated cardiomyopathy with highly reduced systolic pump function and severe mitral valve regurgitation. Inotropic treatment and MitraClip® (Abbott Vascular, Santa Clara, CA, USA) implantation resulted in enhancement of hemodynamics. The rising prevalence of methamphetamine abuse should give reason to raise awareness for the diagnostic work-up and patient history particularly in cases of unexplained cardiomyopathy in young patients.
Subject(s)
Cardiomyopathies/diagnostic imaging , Cardiomyopathy, Dilated/complications , Echocardiography/methods , Methamphetamine/adverse effects , Mitral Valve Insufficiency/diagnostic imaging , Substance-Related Disorders/complications , Cardiomyopathies/surgery , Cardiomyopathy, Dilated/diagnosis , Heart Valve Prosthesis Implantation/methods , Humans , Male , Methamphetamine/administration & dosage , Mitral Valve/diagnostic imaging , Mitral Valve/physiopathology , Mitral Valve/surgery , Mitral Valve Insufficiency/surgery , Treatment Outcome , Young AdultABSTRACT
BACKGROUND: The Cardioband system enables percutaneous surgical-like direct mitral valve annuloplasty and, thereby, repair of severe functional mitral valve regurgitation (MR) in patients with advanced systolic heart failure (HF) and dilation of the left ventricular (LV) annulus. Since the device is anchored by screws in the LV annulus, limited myocardial injury is likely to occur. METHODS AND RESULTS: Five patients (Society of Thoracic Surgeons score: 2.7⯱ 0.7%) with severe HF (LV ejection fraction [LVEF]: 17⯱ 1%; LV end-diastolic diameter [LVEDD]: 71⯱ 3â¯mm) were treated with the Cardioband (sizes C-F) receiving 14-17 screws in the LV annulus region. Myocardial injury was monitored by measuring high-sensitive cardiac troponin T (hsTnT) levels and by echocardiography. All patients showed significant periprocedural increase in hsTnT levels. Peak hsTnT concentration was reached between day 1 and day 6 (593⯱ 141â¯pg/ml). None of the patients showed clinical signs of myocardial infarction, ST-segment elevation, new onset of deteriorated myocardial wall motion, or new ventricular tachycardia. hsTnT levels normalized in all patients after 14 days (hsTnT on day 0: 34⯱ 6â¯pg/ml vs. hsTnT on day 14: 36⯱ 6â¯pg/ml; pâ¯= 0.604). This nonischemic hsTnT kinetics was compared to a sixth patient who experienced proximal damage of the left circumflex artery (LCX) and ST-segment elevation during the Cardioband procedure, followed by immediate repair of the LCX, avoiding structural damage of the LV. CONCLUSION: Cardioband implantation is accompanied by significant elevation of hsTnT without causing structural myocardial damage or clinical symptoms such as worsening of LV function, new-onset LV regions exhibiting reduced wall motion, or ventricular tachycardia.
Subject(s)
Biomarkers , Mitral Valve Annuloplasty , Mitral Valve Insufficiency , Troponin T , Biomarkers/blood , Echocardiography , Humans , Troponin T/blood , Ventricular Function, LeftABSTRACT
Mutations in the human desmin gene cause autosomal-dominant and recessive cardiomyopathies and myopathies with marked phenotypic variability. Here, we investigated the effects of adeno-associated virus (AAV)-mediated cardiac wild-type desmin expression in homozygous desmin knockout (DKO) and homozygous R349P desmin knockin (DKI) mice. These mice serve as disease models for two subforms of autosomal-recessive desminopathies, the former for the one with a complete lack of desmin protein and the latter for the one with solely mutant desmin protein expression in conjunction with protein aggregation pathology in striated muscle. Two-month-old mice were injected with either a single dose of 5 × 1012 AAV9-hTNT2-mDes (AAV-Des) vector genomes or NaCl as control. One week after injection, mice were subjected to a forced swimming exercise protocol for 4 weeks. Cardiac function was monitored over a period of 15 month after injection and before the mice were sacrificed for biochemical and morphological analysis. AAV-mediated cardiac expression of wild-type desmin in both the homozygous DKO and DKI backgrounds reached levels seen in wild-type mice. Notably, AAV-Des treated DKO mice showed a regular subcellular distribution of desmin as well as a normalization of functional and morphological cardiac parameters. Treated DKI mice, however, showed an aberrant subcellular localization of desmin, unchanged functional cardiac parameters, and a trend toward an increased cardiac fibrosis. In conclusion, the effect of a high-dose AAV9-based desmin gene therapy is highly beneficial for the heart in DKO animals, but not in DKI mice.
Subject(s)
Cardiomyopathies , Dependovirus , Animals , Cardiomyopathies/genetics , Cardiomyopathies/therapy , Dependovirus/genetics , Desmin/genetics , Disease Models, Animal , Genetic Therapy , Humans , MiceABSTRACT
Biomarkers have become essential tools for diagnosis and risk stratification in cardiology. This update provides an overview on the development and clinical application of selected biomarkers with a focus on cardiac troponins (cTn). We will specifically indicate the contribution of members of the German Cardiac Society to the field both in test development and evaluation as well as application in clinical care settings. Furthermore, we briefly touch on the development of novel biomarkers and expanded applications in personalized medicine and as companion diagnostics.
Subject(s)
Biomarkers/blood , Cardiology , Heart Diseases/blood , Heart Diseases/diagnosis , HumansABSTRACT
Cardiac biomarkers are an integral part of the diagnostic work-up and risk stratification of patients with chest pain. Cardiac troponins are highly sensitive diagnostic biomarkers in patients with acute coronary syndrome and have prognostic value in a multitude of acute and chronic diseases. In patients with suspected pulmonary embolism (PE) Ddimer can be used together with the Wells score for exclusion of PE. In patients with confirmed PE, Btype natriuretic peptide (BNP), Nterminal pro-BNP (NT-proBNP) and heart-type fatty acid binding protein (h-FABP) can be used for risk stratification. Although normal Ddimer levels largely decrease the possibility of acute aortic dissection, clinicians should not rely on Ddimer alone to exclude the diagnosis of acute aortic syndrome. This continuing medical education article provides an overview of the most important biomarkers recommended in current guidelines for differential diagnoses of patients with chest pain with a focus on cardiac troponins in acute coronary syndrome.
Subject(s)
Biomarkers , Chest Pain , Fatty Acid-Binding Proteins , Heart Diseases , Natriuretic Peptide, Brain , Biomarkers/blood , Chest Pain/etiology , Diagnosis, Differential , Heart Diseases/blood , Heart Diseases/diagnosis , Humans , Peptide Fragments , PrognosisABSTRACT
Missense mutations in the four and a half LIM domain 1 (FHL1) gene were found to cause X-linked inherited myopathies of both skeletal and heart muscles. However, the mechanisms by which FHL1 mutations impact on FHL1 function and lead to alteration of muscle structure and function have not been deciphered yet. We generated here by Morpholino-modified antisense oligonucleotide-mediated gene knockdown fHL1-deficient zebrafish embryos. Similar to the human situation, fhl1a-morphants zebrafish displayed severe skeletal and heart muscle myopathy. Whereas ectopic expression of wild-type FHL1 (FHL1 wt) suppressed both skeletal and heart muscle myopathy in fhl1a-morphants zebrafish, overexpression of the FHL1-opathy associated human mutations FHL1-H123Y, FHL1-C132F or FHL1-C224W did not rescue skeletal and heart muscle myopathy in fhl1a-morphants. Overexpression of FHL1-H123Y, FHL1-C132F or FHL1-C224W in wild-type zebrafish did not induce myopathy in a dominant-negative mode. Altogether these results indicate that FHL1 mutations found to cause X-linked FHL1-opathies in humans consistently lead to severely impaired FHL1 function.
Subject(s)
Intracellular Signaling Peptides and Proteins/genetics , LIM Domain Proteins/genetics , Muscle Proteins/genetics , Muscle, Skeletal/pathology , Muscular Diseases/genetics , Mutation , Myocardium/pathology , Animals , Disease Models, Animal , Genes, X-Linked , Humans , Muscle, Skeletal/metabolism , Muscular Diseases/metabolism , Muscular Diseases/pathology , Myocardium/metabolism , ZebrafishABSTRACT
The number of patients with atrial fibrillation undergoing percutaneous coronary intervention (PCI) is increasing. Since these patients have a CHA2DS2-VASc score of 1 or higher, they should be treated with oral anticoagulation to prevent stroke. However, combination therapy with oral anticoagulation for prevention of embolic stroke and dual platelet inhibition for prevention of coronary thrombosis significantly increases bleeding complications. The optimal combination, intensity and duration of antithrombotic combination therapy is still not known. In the rather small randomized WOEST trial, the combination of a vitamin K antagonist (VKA) and clopidogrel decreased bleeding compared to the conventional triple therapy with VKA, clopidogrel and aspirin. In the PIONEER AF-PCI trial, two rivaroxaban-based treatment regimens significantly reduced bleeding complications compared to conventional triple therapy without increasing embolic or ischemic complications following PCI. Dual therapy with rivaroxaban and clopidogrel appeared to provide an optimal risk-benefit ratio. In the RE-DUAL PCI trial, dual therapy with dabigatran also reduced bleeding complications compared to conventional triple therapy. With respect to the composite efficacy end point of thromboembolic events (myocardial infarction, stroke, or systemic embolism), death, or unplanned revascularization dabigatran-based dual therapy was non-inferior to VKA-based triple therapy. The upcoming trials AUGUSTUS with apixaban and ENTRUST-PCI with edoxaban will further examine the use of NOACs in this setting. While recent guidelines recommend NOAC-based dual therapy in only a subset of patients (those who are at increased risk of bleeding), the available data now suggest that this should be the preferred choice for the majority of patients. Adding aspirin to this primary choice for up to 4 weeks in patients at especially high ischemic risk would likely prevent atherothrombotic events, but this needs further investigation. Taken together, it is time to adjust our practice and move to dual therapy consisting of a NOAC plus clopidogrel in most patients.
Subject(s)
Anticoagulants/administration & dosage , Atrial Fibrillation/drug therapy , Fibrinolytic Agents/administration & dosage , Percutaneous Coronary Intervention , Stroke/prevention & control , Administration, Oral , Anticoagulants/adverse effects , Atrial Fibrillation/complications , Atrial Fibrillation/diagnosis , Atrial Fibrillation/mortality , Clopidogrel , Drug Administration Schedule , Evidence-Based Medicine , Fibrinolytic Agents/adverse effects , Hemorrhage/chemically induced , Humans , Percutaneous Coronary Intervention/adverse effects , Percutaneous Coronary Intervention/mortality , Platelet Aggregation Inhibitors/administration & dosage , Platelet Aggregation Inhibitors/adverse effects , Practice Guidelines as Topic , Practice Patterns, Physicians' , Randomized Controlled Trials as Topic , Risk Assessment , Risk Factors , Stroke/diagnosis , Stroke/etiology , Stroke/mortality , Ticlopidine/administration & dosage , Ticlopidine/adverse effects , Ticlopidine/analogs & derivatives , Treatment OutcomeABSTRACT
The downregulation of ß-adrenergic receptors (ß-AR) and decreased cAMP-dependent protein kinase activity in failing hearts results in decreased phosphorylation and inactivation of phosphatase-inhibitor-1 (I-1), a distal amplifier element of ß-adrenergic signaling, leading to increased protein phosphatase 1 activity and dephosphorylation of key phosphoproteins, including phospholamban. Downregulated and hypophosphorylated I-1 likely contributes to ß-AR desensitization; therefore its modulation is a promising approach in heart failure treatment. Aim of our study was to assess the effects of adeno-associated virus serotype 9 (AAV9) - mediated cardiac-specific expression of constitutively active inhibitor-1 (I-1c) and to investigate whether I-1c is able to attenuate the development of heart failure in mice subjected to transverse aortic constriction (TAC). 6-8 week old C57BL/6 N wild-type mice were subjected to banding of the transverse aorta (TAC). Two days later 2.8 × 1012 AAV-9 vector particles harbouring I-1c cDNA under transcriptional control of a human troponin T-promoter (AAV9/I-1c) were intravenously injected into the tail vein of these mice (n=12). AAV9 containing a Renilla luciferase reporter (AAV9/hRluc) was used as a control vector (n=12). Echocardiographic analyses were performed weekly to evaluate cardiac morphology and function. 4 weeks after TAC pressure- volume measurements were performed and animals were sacrificed for histological and molecular analyses. Both groups exhibited progressive contractile dysfunction and myocardial remodeling. Surprisingly, echocardiographic assessment and histological analyses showed significantly increased left ventricular hypertrophy in AAV9/I-1c treated mice compared to AAV9/hRluc treated controls as well as reduced contractility. Pressure-volume loops revealed significantly impaired contractility after AAV9/I-1c treatment. At the molecular level, hearts of AAV9/I-1c treated TAC mice showed a hyperphosphorylation of the SR Ca2+-ATPase inhibitor phospholamban. In contrast, expression of AAV9/I-1c in unchallenged animals resulted in selective enhancement of phospholamban phosphorylation and augmented cardiac contractility. Our data suggest that AAV9-mediated cardiac-specific overexpression of I-1c, previously associated with enhanced calcium cycling, improves cardiac contractile function in unchallenged animals but failed to protect against cardiac remodeling induced by hemodynamic stress questioning the use of I-1c as a potential strategy to treat heart failure in conditions with increased afterload.
Subject(s)
Dependovirus , Genetic Therapy/methods , Heart Failure/therapy , Intracellular Signaling Peptides and Proteins/genetics , Myocardial Contraction/genetics , Animals , Calcium-Binding Proteins/metabolism , Disease Models, Animal , Echocardiography , Gene Expression , Genetic Vectors , Humans , Intracellular Signaling Peptides and Proteins/metabolism , Mice, Inbred C57BL , Mice, Transgenic , Phosphorylation , Promoter Regions, Genetic , Troponin T/geneticsABSTRACT
Evidence-based medicine has considerably advanced the treatment of highly prevalent cardiovascular diseases. Its implementation was driven by multicenter interventional trials in treatment and placebo cohorts, propelling numerous biomedical innovations toward standard of care. While a uniform treatment can be effective in such disease cohorts ("one size fits all"), it neglects the genetic and phenotypic individuality of a single patient and his or her disease. Accordingly, a recent observation was made that several newer "mega" trials, demanding considerable resources for their execution, showed statistically significant differences in outcome, however, with small overall efficacies that render implementation in the clinics unlikely. To overcome this concerning development, new methods for individualized treatment of cardiovascular disease are required. Rarer conditions, such as distinct cardiomyopathies, may deliver the blueprint for a paradigm shift: deep and precise phenotyping of individual patients by a multimodal approach and development of targeted treatments for smaller groups ("one treatment for many") or even for single patients ("one treatment of some").
Subject(s)
Cardiomyopathies/therapy , Cardiovascular Diseases/therapy , Precision Medicine/methods , Biological Products/therapeutic use , Cardiomyopathies/genetics , Cardiovascular Diseases/genetics , Combined Modality Therapy , Genotype , Humans , Molecular Targeted Therapy , Phenotype , Treatment OutcomeABSTRACT
OBJECTIVES: To analyze clinical predictors of mortality in wild-type transthyretin amyloidosis (wt-ATTR). METHODS: In total, 191 patients (73.8 ± 0.5 years; 176 males, 15 females) with histologically proven wt-ATTR amyloidosis and genetic exclusion of a transthyretin gene variant were included. Comprehensive clinical characteristics, ECG, biomarkers, and echocardiography were analyzed retrospectively. Strain analyses were performed offline using TomTec Imaging Systems, Germany. Univariable and multivariable analyses predicting all-cause mortality were carried out. RESULTS: Patients presented with significant heart failure (NYHA 2.5 ± 0.8; NT-proBNP 3644 (4981) pg/ml; LV ejection fraction 45.8 ± 15.0%). LogNT-proBNP correlated with indicators of disease severity. Similar results were obtained for basal and midventricular, but not apical longitudinal strain. During median follow-up of 26.2 ± 1.7 months 46 (25.5%) patients died (40 males, 23%; six females, 40%). In female patients 1-/2-year survival was lower [92.9/67.7%; median survival 30.6 (21.1-40.1) months] when compared to male patients [96.5%/86.6%; median survival 63.9 (45.8-82.0) months]. Parameters associated with survival were NT-proBNP, NYHA class, heart rate, midventricular longitudinal strain, mitral annular plane systolic excursion (MAPSE), Karnofsky Index, systolic blood pressure, estimated glomerular filtration rate. Multivariable analysis revealed MAPSE and NT-proBNP as independent predictors of mortality in the whole cohort and midventricular strain in the subgroup of patients in sinus rhythm. CONCLUSIONS: No sex-specific bias was observed between male and female patients with wt-ATTR regarding age at onset and morphological characteristics. Multivariable analysis revealed MAPSE and NT-proBNP as independent predictors of survival in the whole cohort, whereas midventricular longitudinal strain was the only independent predictor in patients in sinus rhythm.
Subject(s)
Amyloid Neuropathies, Familial/mortality , Cardiomyopathies/mortality , Aged , Aged, 80 and over , Amyloid Neuropathies, Familial/diagnostic imaging , Amyloid Neuropathies, Familial/physiopathology , Biomarkers/blood , Blood Pressure , Cardiomyopathies/diagnostic imaging , Cardiomyopathies/physiopathology , Echocardiography , Electrocardiography , Female , Germany/epidemiology , Heart Rate , Humans , Kaplan-Meier Estimate , Karnofsky Performance Status , Male , Mitral Valve/physiopathology , Multivariate Analysis , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Prognosis , Proportional Hazards Models , Retrospective Studies , Risk Assessment , Risk Factors , Stroke Volume , Time Factors , Ventricular Function, LeftABSTRACT
AIMS: Cardiovascular disease, one of the most common causes of death in western populations, is characterized by changes in RNA splicing and expression. Circular RNAs (circRNA) originate from back-splicing events, which link a downstream 5' splice site to an upstream 3' splice site. Several back-splicing junctions (BSJ) have been described in heart biopsies from human, rat and mouse hearts (Werfel et al., 2016; Jakobi et al., 2016 ). Here, we use human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) to identify circRNA and host gene dynamics in cardiac development and disease. In parallel, we explore candidate interactions of selected homologs in mouse and rat via RIP-seq experiments. METHODS AND RESULTS: Deep RNA sequencing of cardiomyocyte development and ß-adrenergic stimulation uncovered 4518 circRNAs. The set of circular RNA host genes is enriched for chromatin modifiers and GTPase activity regulators. RNA-seq and qRT-PCR data showed that circular RNA expression is highly dynamic in the hiPSC-CM model with 320 circRNAs showing significant expression changes. Intriguingly, 82 circRNAs are independently regulated to their host genes. We validated the same circRNA dynamics for circRNAs from ATXN10, CHD7, DNAJC6 and SLC8A1 in biopsy material from human dilated cardiomyopathy (DCM) and control patients. Finally, we could show that rodent homologs of circMYOD, circSLC8A1, circATXN7 and circPHF21A interact with either the ribosome or Argonaute2 protein complexes. CONCLUSION: CircRNAs are dynamically expressed in a hiPSC-CM model of cardiac development and stress response. Some circRNAs show similar, host-gene independent expression dynamics in patient samples and may interact with the ribosome and RISC complex. In summary, the hiPSC-CM model uncovered a new signature of potentially disease relevant circRNAs which may serve as novel therapeutic targets.
Subject(s)
Cardiomyopathy, Dilated/metabolism , Gene Expression Regulation , Induced Pluripotent Stem Cells/metabolism , Models, Cardiovascular , Muscle Proteins/biosynthesis , Myocytes, Cardiac/metabolism , RNA/metabolism , Animals , Cardiomyopathy, Dilated/genetics , Cardiomyopathy, Dilated/pathology , Humans , Induced Pluripotent Stem Cells/pathology , Mice , Muscle Proteins/genetics , Myocytes, Cardiac/pathology , RNA/genetics , RNA, Circular , RatsABSTRACT
Precision medicine aims to achieve improved survival by strategies that recognize the genetic and phenotypic individuality of patients and stratify treatment accordingly. Genetic cardiomyopathies represent an ideal disease group to fully embark on this concept: they are in total frequent diseases with a marked morbidity and mortality and there is ample knowledge about their predisposing genetic factors and associated functional mechanisms. The current review highlights the genetic etiology and gives examples of the diverse treatment strategies that are envisaged in the future.