Macrophages enhance sodium channel expression in cardiomyocytes.

Cardiac macrophages facilitate electrical conduction through the atrioventricular-node (AV) in mice. A possible role for cardiomyocyte-macrophage coupling on the effect of antiarrhythmic therapy has not been investigated yet. Holter monitoring was conducted in LysMCrexCsf1rLsL-DTR mice (MMDTR) under baseline conditions and after an elctrophysiological stress test by flecainide. In vivo effects were recapitulated in vitro by patch-clamp experiments. The underlying mechanism was characterized by expression and localization analysis of connexin43 (Cx43) and voltage-gated-sodium-channel-5 (Nav1.5). ECG monitoring in MMDTR mice did not show any significant conduction abnormalities but a significantly attenuated flecainide-induced extension of RR- and PP-intervals. Patch-clamp analysis revealed that the application of flecainide to neonatal rat ventricular cardiomyocytes (CMs) changed their resting-membrane-potential (RMP) to more negative potentials and decreased action-potential-duration (APD50). Coupling of macrophages to CMs significantly enhances the effects of flecainide, with a further reduction of the RMP and APD50, mediated by an upregulation of Cx43 and Nav1.5 surface expression. Macrophage depletion in mice does not correlate with cardiac electric conduction delay. Cardiac macrophages amplify the effects of flecainide on electrophysiological properties of cardiomyocytes in vivo and in vitro. Mechanistically, formation of macrophage-cardiomyocyte cell-cell-contacts via Cx43 facilitates the recruitment of Nav1.5 to the cell membrane increasing flecainide effects.

[Digitalization and clinical decision tools]. / Digitalisierung und Clinical Decision Tools.

Digitalization in cardiovascular emergencies is rapidly evolving, analogous to the development in medicine, driven by the increasingly broader availability of digital structures and improved networks, electronic health records and the interconnectivity of systems. The potential use of digital health in patients with acute chest pain starts even in the prehospital phase with the transmission of a digital electrocardiogram (ECG) as well as telemedical support and digital emergency management, which facilitate optimization of the rescue pathways and reduce critical time intervals. The increasing dissemination and acceptance of guideline apps and clinical decision support tools as well as integrated calculators and electronic scores are anticipated to improve guideline adherence, translating into a better quality of treatment and improved outcomes. Implementation of artificial intelligence to support image analysis and also the prediction of coronary artery stenosis requiring interventional treatment or impending cardiovascular events, such as heart attacks or death, have an enormous potential especially as conventional instruments frequently yield suboptimal results; however, there are barriers to the rapid dissemination of corresponding decision aids, such as the regulatory rules related to approval as a medical product, data protection issues and other legal liability aspects, which must be considered.

Ythdf2 regulates cardiac remodeling through its mRNA target transcripts.

m6A mRNA methylation controls cardiomyocyte function and increased overall m6A levels are a stereotyping finding in heart failure independent of the underlying etiology. However, it is largely unknown how the information is read by m6A reader proteins in heart failure. Here we show that the m6A reader protein Ythdf2 controls cardiac function and identified a novel mechanism how reader proteins control gene expression and cardiac function. Deletion of Ythdf2 in cardiomyocytes in vivo leads to mild cardiac hypertrophy, reduced heart function, and increased fibrosis during pressure overload as well as during aging. Similarly, in vitro the knockdown of Ythdf2 results in cardiomyocyte growth and remodeling. Mechanistically, we identified the eucaryotic elongation factor 2 as post-transcriptionally regulated by Ythdf2 using cell type specific Ribo-seq data. Our study expands our understanding on the regulatory functions of m6A methylation in cardiomyocytes and how cardiac function is controlled by the m6A reader protein Ythdf2.

[Quality indicators and structural requirements for Cardiac Arrest Centers-Update 2021]. / Qualitätskriterien und strukturelle Voraussetzungen für Cardiac Arrest Zentren ­ Update 2021: Deutscher Rat für Wiederbelebung/German Resuscitation Council (GRC).

An update of the first description of quality indicators and structural requirements for Cardiac Arrest Centers from 2017 based on first experiences and certifications is presented. Criteria were adjusted, substantiated and in some parts redefined for feasibility in everyday clinical use.

AAV-mediated cardiac gene transfer of wild-type desmin in mouse models for recessive desminopathies.

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.

Hyperlipidaemia and incident osteoarthritis of the hand: a population-based case-control study.

OBJECTIVE: Preclinical evidence suggests that increased cholesterol levels might be involved in the pathophysiology of osteoarthritis of the hand (HOA), but evidence from observational studies remains scarce. We aimed to analyse the association between hyperlipidaemia and incident HOA. DESIGN: We conducted a matched (1:1) case-control study using the UK-based Clinical Practice Research Datalink (CPRD). Cases were patients aged 30-89 years with an incident diagnosis of HOA between 1995 and 2014. In multivariable conditional logistic regression analyses, we calculated odds ratios (OR) for incident HOA in patients with hyperlipidaemia, categorized by gender, age, previous duration of hyperlipidaemia, and recent statin treatment. RESULTS: Among 19,590 cases and 19,590 controls, we observed an increased risk of HOA in patients with hyperlipidaemia (OR 1.37, 95% confidence intervals (CI) 1.28-1.47), when compared to patients without hyperlipidaemia. Thus, of all HOA cases in our study population, 3.6% may have been attributable to the presence of hyperlipidaemia (population attributable risk). Most patients with HOA were elderly, but the strength of the association between HOA and hyperlipidaemia inversely correlated with increasing age, with the highest OR of 1.72 (95% CI 1.24-2.38) in patients aged 29-49 years. Categorization by previous hyperlipidaemia duration, as well as sub-classification of patients with hyperlipidaemia into those with and without recent statin use did not meaningfully change the effect estimate. CONCLUSIONS: Our results suggest that hyperlipidaemia may be an independent risk factor for new onset HOA.

Influence of hyperoxia on diastolic myocardial and arterial endothelial function.

OBJECTIVE: Hyperoxia is known to influence cardiovascular and endothelial function, but it is unknown if there are differences between younger and older persons. The aim of this study was to monitor changes in myocardial diastolic function and flow-mediated dilatation (FMD) in younger and elderly volunteers, before and after exposure to relevant hyperbaric hyperoxia. METHODS: 51 male patients were separated into two groups for this study. Volunteers in Group 1 (n=28, mean age 26 ±6, "juniors") and Group 2 (n=23, mean age 53 ±9, "seniors") received standard HBO2 protocol (240kPa oxygen). Directly before and after hyperoxic exposure in a hyperbaric chamber we took blood samples (BNP, hs-troponin-t), assessed the FMD and echocardiographic parameters with focus on diastolic function. RESULTS: After hyperoxia we observed a high significant decrease in heart rate and systolic/diastolic FMD. Diastolic function varied in both groups: E/A ratio showed a statistically significant increase in Group 1 and remained unchanged in Group 2. E/e' ratio showed a slight but significant increase in Group 1, whereas e'/a' ratio increased in both groups. Deceleration time increased significantly in all volunteers. Isovolumetric relaxation time remained unchanged and ejection fraction showed a decrease only in Group 2. There were no changes in levels of BNP and hs-troponin-t in either group. CONCLUSION: Hyperoxia seems to influence endothelial function differently in juniors and seniors: FMD decreases more in seniors, possibly attributable to pre-existing reduced vascular compliance. Hyperoxia-induced bradycardia induced a more pronounced improvement in diastolic function in juniors. The ability of Group 1 to cope with hyperoxia-induced effects did not work in the same manner as with Group 2.

[Choosing wisely recommendations in cardiology]. / Klug-entscheiden-Empfehlungen in der Kardiologie.

This article describes controversially discussed Choosing wisely recommendations presented by the German Cardiac Society: anticoagulation therapy in patients with atrial fibrillation and "only" moderate stroke risk, on the one hand, and goal-directed low-density lipoprotein (LDL) cholesterol-lowering, on the other. Presuming an adequate regime, patients with atrial fibrillation and only moderate risk of stroke (CHA2DS2-VASc Score of 1 in men and of 2 in women) also benefit from anticoagulation therapy, even in elderly patients. In patients with coronary heart disease, the German Cardiac Society recommends reducing LDL-cholesterol serum levels with a statin to values lower than 70 mg/dl (1.8 mmol/l) or at least reducing the basal level by 50%. With this recommendation, the German Cardiac Society unequivocally prioritizes the "goal-oriented statin therapy" above the "statin strategy of fixed dose". The reasons for this preference are discussed.

Type II diabetes mellitus and incident osteoarthritis of the hand: a population-based case-control analysis.

OBJECTIVES: Emerging evidence suggests that diabetes may be a risk factor for osteoarthritis (OA). However, previous results on the association between diabetes and all OA were conflicting. We aimed to comprehensively analyse the association between type II diabetes mellitus (T2DM) and osteoarthritis of the hand (HOA) specifically. METHODS: We conducted a matched (1:1) case-control study using the UK-based Clinical Practice Research Datalink (CPRD) of cases aged 30-90 years with an incident diagnosis of HOA from 1995 to 2013. In multivariable conditional logistic regression analyses, we calculated odds ratios (OR) for incident HOA in patients with T2DM, categorized by T2DM severity (HbA1C), duration, and pharmacological treatment. We further performed sensitivity analyses in patients with and without other metabolic diseases (hypertension (HT), hyperlipidaemia (HL), obesity). RESULTS: Among 13,500 cases and 13,500 controls, we observed no statistically significant association between T2DM and HOA (OR 0.95, 95% confidence interval (CI) 0.87-1.04), regardless of T2DM severity, duration, or pharmacological treatment. Having HT did not change the OR. Although we observed slightly increased ORs in overweight T2DM patients with co-occurring HL with or without coexisting HT, none of these ORs were statistically significant. CONCLUSIONS: Our results provide evidence that T2DM is not an independent risk factor for HOA. Concurrence of T2DM with HT, HL, and/or obesity did not change this association significantly.

Late enhanced computed tomography in Hypertrophic Cardiomyopathy enables accurate left-ventricular volumetry.

OBJECTIVES: Late enhancement (LE) multi-slice computed tomography (leMDCT) was introduced for the visualization of (intra-) myocardial fibrosis in Hypertrophic Cardiomyopathy (HCM). LE is associated with adverse cardiac events. This analysis focuses on leMDCT derived LV muscle mass (LV-MM) which may be related to LE resulting in LE proportion for potential risk stratification in HCM. METHODS: N=26 HCM-patients underwent leMDCT (64-slice-CT) and cardiovascular magnetic resonance (CMR). In leMDCT iodine contrast (Iopromid, 350 mg/mL; 150mL) was injected 7 minutes before imaging. Reconstructed short cardiac axis views served for planimetry. The study group was divided into three groups of varying LV-contrast. LeMDCT was correlated with CMR. RESULTS: The mean age was 64.2 ± 14 years. The groups of varying contrast differed in weight and body mass index (p < 0.05). In the group with good LV-contrast assessment of LV-MM resulted in 147.4 ± 64.8 g in leMDCT vs. 147.1 ± 65.9 in CMR (p > 0.05). In the group with sufficient contrast LV-MM appeared with 172 ± 30.8 g in leMDCT vs. 165.9 ± 37.8 in CMR (p > 0.05). Overall intra-/inter-observer variability of semiautomatic assessment of LV-MM showed an accuracy of 0.9 ± 8.6 g and 0.8 ± 9.2 g in leMDCT. All leMDCT-measures correlated well with CMR (r > 0.9). CONCLUSIONS: LeMDCT primarily performed for LE-visualization in HCM allows for accurate LV-volumetry including LV-MM in > 90% of the cases. KEY POINTS: • LeMDCT of relatively low contrast allows for LV planimetry in HCM. • The correlation of leMDCT-based LV volumetry with gold-standard CMR was excellent (r > 0.9). • LeMDCT requires approximately 2.0mL/kgBW of dye to achieve acceptable contrast.

Cardiomyocyte-specific RXFP1 overexpression protects against pressure overload-induced cardiac dysfunction independently of relaxin.

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.

[Deep vein thrombosis as a primary symptom of abdominal aortic aneurysm : Bilateral deep vein thrombosis caused by infrarenal abdominal aortic aneurysm (15 cm in diameter) with complete compression of the inferior vena cava]. / Tiefe Venenthrombose als Primärsymptom eines abdominellen Aortenaneurysmas : Beidseitige 4-Etagen-TVT durch infrarenales Bauchaortenaneurysma (15 cm Durchmesser) mit vollständiger Kompression der V. cava inferior.

This article presents the case of a 70-year-old obese patient with severe bilateral leg pain due to deep vein thrombosis. After unsuccessful venous recanalization, computed tomography angiography revealed an abdominal aortic aneurysm 15 cm in diameter with total compression of the inferior vena cava. For venous decompression as well as rupture prophylaxis, conventional open surgical repair was performed.

Decoding calcium signals involved in cardiac growth and function.

Calcium is central in the regulation of cardiac contractility, growth and gene expression. Variations in the amplitude, frequency and compartmentalization of calcium signals are decoded by calcium/calmodulin-dependent enzymes, ion channels and transcription factors. Understanding the circuitry for calcium signaling creates opportunities for pharmacological modification of cardiac function.

[New approaches and indications for the analysis of platelet function in cardiology]. / Neue Ansätze und Indikationen zur Plättchenfunktionsdiagnostik in der Kardiologie.

Inhibiting platelet function is a key therapeutic principle in cardiology because platelets play a pivotal role in triggering cardiovascular events. In addition to acetylsalicylic acid, a cyclooxygenase inhibitor, ADP-receptor blockers are frequently used for anti-platelet therapy. This therapy does not abolish platelet activation and aggregation. Platelets may still be activated by alternative routes such as the thrombin receptor-mediated pathway. New, more potent inhibitors of platelet function continue to lower the risk of ischaemic events but several trials and clinical registries have also shown that this advantage was frequently offset by an increased risk of bleeding complications. As a consequence, the individual risk of ischaemia and bleeding of a patient must be taken into consideration to select the platelet inhibitor offering the best benefit-risk ratio. Modern laboratory diagnostics may help to achieve this goal by complementing functional platelet tests with pharmacogenomic analyses consistent with the idea of "personalized medicine".

Diagnosis and treatment of cardiac amyloidosis: position statement of the German Cardiac Society (DGK).

Systemic forms of amyloidosis affecting the heart are mostly light-chain (AL) and transthyretin (ATTR) amyloidoses. The latter is caused by deposition of misfolded transthyretin, either in wild-type (ATTRwt) or mutant (ATTRv) conformation. For diagnostics, specific serum biomarkers and modern non-invasive imaging techniques, such as cardiovascular magnetic resonance imaging (CMR) and scintigraphic methods, are available today. These imaging techniques do not only complement conventional echocardiography, but also allow for accurate assessment of the extent of cardiac involvement, in addition to diagnosing cardiac amyloidosis. Endomyocardial biopsy still plays a major role in the histopathological diagnosis and subtyping of cardiac amyloidosis. The main objective of the diagnostic algorithm outlined in this position statement is to detect cardiac amyloidosis as reliably and early as possible, to accurately determine its extent, and to reliably identify the underlying subtype of amyloidosis, thereby enabling subsequent targeted treatment.

Gene transfer to the vascular system: Novel translational perspectives for vascular diseases.

Although vessels are directly exposed to the bloodstream, vascular gene transfer is rarely used as a tool for preclinical studies for several reasons: (i) viral and non-viral vectors show a low transduction efficiency in the vascular system; (ii) classical vascular gene therapy approaches such as treatment of peripheral or cardiac ischemia are focusing on non-vascular target cells; and (iii) vascular diseases are rarely monogenetic, thus gene replacement approaches are uncommon. Here, we provide an overview of recent approaches in developing novel vectors and modes of application for improved transduction efficiency of large and small vessels. Increased availability of such tools for vascular gene transfer has already facilitated preclinical studies addressing a broad variety of vascular diseases like transplant vasculopathy, atherosclerosis, and hereditary aortic diseases such as Marfan syndrome.

The role of endothelial cell biology in endocarditis.

The treatment of endocarditis remains a challenge for physicians, even in times of modern antibiotic treatment. Depending on its cause, endocarditis can either be of infectious or non-infectious origin. Infective endocarditis is caused by bacterial (or fungal) pathogens, and the clinical course is critically dependent on the virulence factors of the specific microorganisms involved. Therefore, the clinical type of endocarditis can be divided into an acute and more aggressive form and a subacute form (endocarditis lenta). Much of our knowledge regarding the pathogenesis of infective endocarditis is based on studies of the virulence of Staphylococcus aureus, which has become the most frequent cause of infective endocarditis nowadays. However, independently of the underlying cause of endocarditis (infectious or noninfectious), the pathogenesis involves the damage and disturbance of endothelial function and the formation of associated "vegetation". Surprisingly little is known about the specific role of the endothelium in the pathogenesis of endocarditis. This review will thus give insights into current knowledge of the pathogenesis of endocarditis with a focus on the role of the endothelium.

[Dilated cardiomyopathy as a genetic disease: molecular and clinical aspects]. / Die dilatative Kardiomyopathie als genetische Erkrankung : Molekulare und klinische Aspekte.

Dilated cardiomyopathy is a disease of heterogenous etiology. In up to 50% of cases, familial aggregation is observed. During the past decade, several DCM-causing mutations could be identified, several of these in sarcomeric proteins. A specific component of the sarcomere, the z-disc, appears to be a "hot spot" in the molecular pathogenesis of DCM. Yet, mutations in proteins of the sarcolemma, the cytoskeleton, as well as the nuclear membrane can also lead to dilated cardiomyopathy. Morever, in addition to the monogenetic causes of cardiomyopathy, the genetic background of the individual patient may critically determine disease progression and the response to therapy. In the initial clinical evaluation of a patient newly diagnosed with DCM, it is important to obtain a careful family history in order to detect and treat additional family members which may be affected. Moreover, extracardiac manifestations of genetic DCM, such as skeletal muscle involvement, should be excluded. We anticipate that the elucidation of additional DCM disease genes as well as the underlying molecular pathways should lead to the development of novel specific therapies in the future.