Chronic heart failure as a sequel of severe burn injury: first insight into a novel pathological heart-skin axis

Research question

Our clinical research unveiled chronic heart failure with preserved ejection fraction (HFpEF) as a long-term sequel in survivors of severe pediatric burn injury due to a yet unknown molecular pathomechanism (1). Applying a standardized scald injury rat model, which is widely used in burn research, we systematically determined the pathophysiological impact of burn injury on cardiac performance to uncover systemic and molecular pathomechanisms that may cause post-burn injury HFpEF development.

Methods

Male adolescent SD-rats were subjected to a 60% total body surface area (TBSA) full-thickness burn- or sham-trauma and subsequently characterized by serial transthoracic echocardiography, bulk myocardial next-generation sequencing and proteomics as well as RT-PCR, immuno-blotting (IB), histology and plasma proteomics for cardiac performance and molecular alterations, for up to 90 days (3, 7, 30 and 90d).

Results

In comparison to the sham-group (SG, n=10), animals from the burn-group (BG, n=10; survival rate 100%) recapitulated typical post-burn clinical traits, such as significant loss in body weight (BG 27% less than SG at 30d, p<0.05) or skeletal muscle wasting (i.e., 27% less at 30d, p<0.05) in accord with elevated molecular atrophy markers throughout the observation period. Our focus on the heart revealed for the first-time post-burn cardiac muscle wasting (BG 22% less at 30d, p<0.05) and persistent markers of cardiac dysfunction in accord with significant histological cardiomyocyte hypotrophy (BG −8% at 30d, p<0.05) and significantly diminished left ventricular (LV) global longitudinal strain and isovolumic relaxation time in BGs, while LV-EF remained unchanged. Subsequent IB analysis uncovered diminished protein synthesis activity and diminished mTOR pathway activity in BG hearts. Weighted gene network correlation analysis i.e., from bulk myocardial NGS and clinical traits related activation of immunological and pro-fibrotic pathways in post-burn injury hearts to cardiac dysfunction in BGs. Subsequent RT-PCR and histology confirmed significant myocardial accumulation of cardio-depressive damage associated molecular patterns (i.e., S100A8 and A9) and infiltration by granulocytes (myeloperoxidase+) and monocytes (CD 68+) as well as significant LV fibrosis. Serial plasma proteomic analysis indicated elevated plasma levels i.e., of S100A8 and A9 and other heart failure markers that mirrored similar changes in human post-burn injury plasma samples.

Conclusion

Here we report for the first time the development of HFpEF as a novel systemic consequence of severe burn injury in a rodent model, which prepares the ground for further mechanistic and translational studies. The initial observation of cardiac inflammation and fibrosis, which are known to negatively impact cardiac performance, may be mechanistic key findings that will guide further therapeutic studies and subsequent validation of post-burn heart failure biomarkers.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Rolf-Schwiete Stiftung

Abstract P3020: Chronic Heart Failure As A Sequel After Severe Burn Injury - First Insight Into A Novel Pathological Heart-skin Axis

Background: We described chronic heart failure with preserved ejection fraction (HFpEF) as a long-term sequel in survivors of severe pediatric burn injury (BI) (Hundeshagen et al., Lancet Child & Adolescent Health, 2017). Applying a widely used standardized scald injury rat model in burn research, we sought to uncover systemic and molecular pathomechanisms that may cause post-BI HFpEF development.

Methods and Results: Male adolescent SD-rats were subjected to a 60% total body surface area full-thickness BI (B; 100% survival) or sham (S) procedure (each n=10) and characterized them up to 90 days (3, 7, 30 and 90d) by serial echocardiography (E), bulk myocardial NGS and -proteomics, RT-PCR, IB, histology (H) and plasma proteomics for cardiac performance and molecular alterations, respectively. B rats mirrored typical post-burn clinical traits as significant loss in body (-27%*) or skeletal muscle weight (-30%*) e.g., with elevated atrophy markers as Murf1 (5-fold*) throughout the observation period vs S (30d, *P<0.05) Our focus on the heart revealed in vivo heart weight loss (-22%*), cardiomyocyte hypotrophy (-8%*) and diminished mTOR activity in B hearts (p/t-mTORC2 -43%*) vs S as well as significantly diminished left ventricular (LV) GLS with unchanged LV-EF. RT-PCR and H showed significant cardiac accumulation of cardiodepressive factors (i.e., S100A8 and A9) and e.g., granulocyte (MPO, >3-fold*) infiltration as well LV fibrosis (2.2-fold*). Cardiac proteomics yielded e.g., neutrophil degranulation as lead GO-term. Serial blood and plasma proteomic and ELISA analysis indicated elevated WBC (+26%*) and levels e.g., of IL6, S100A8/A9, CH3L1 and other HF markers alike changes in human post-BI plasma samples. WGCNA for bulk myocardial NGS and clinical traits related activated immunological and pro-fibrotic pathways in post-BI hearts to cardiac dysfunction in B.

Conclusion: The first ever report of the development of HFpEF as a novel systemic consequence of severe burn injury in a rodent model prepares the ground for further mechanistic and translational studies. Cardiac inflammation and fibrosis that negatively impact cardiac performance may be mechanistic key findings guiding further therapeutic studies and validation of post-BI HF biomarkers.

Long-term sequelae of critical illness in sepsis, trauma and burns: A systematic review and meta-analysis

BACKGROUND

Sepsis, major trauma, and severe burn injury are life-threatening critical illnesses that remain significant contributors to worldwide morbidity and mortality. The three underlying etiologies share pathophysiological similarities: hyperinflammation, hypermetabolism, and acute immunomodulation. The aims of this study were to assess the current state of long-term outcome research and to identify key outcome parameters between the three forms of critical illness.

METHODS

This systematic review and meta-analysis (MA) were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. PubMed was searched from January 1, 1975, to December 31, 2019. Studies were assessed for eligibility by independent reviewers. Inclusion criteria were studies reporting at least a 6-month follow-up of health-related quality of life and organ-specific sequelae within the three etiologies: severe burn injury, sepsis, and major trauma.

RESULTS

In total, 125 articles could be included in the systematic review and 74 in the MA. The mean follow-up time was significantly longer in burn studies, compared with sepsis and trauma studies. The majority of patients were from the sepsis group, followed by burns, and major trauma studies. In the overall health-related quality of life, as assessed by Short Form 36 and European Quality-of-Life Index, the three different etiologies were comparable with one another.

CONCLUSION

The effects of critical illness on survivors persist for years after hospitalization. Well-reported and reliable data on the long-term outcomes are imperative, as they can be used to determine the treatment choice of physicians and to guide the expectations of patients, improving the overall quality of care of three significant patient cohorts.

LEVEL OF EVIDENCE

Systematic review and MA, level III.

Low-melting imidazolium-based salts with the paramagnetic reineckate-analogue anion [Cr(NCS)4(bipy)]- (bipy = 2,2'-bipyridine): syntheses, properties, and structures

In order to investigate the potential ionic liquid properties of Reineckate-analogue materials, four new salts, consisting of the heteroleptic [Cr(NCS)(4)(bipy)](-) complex anion and imidazolium-based cations A(+) = 1-ethyl-3-methylimidazolium, 1-n-butyl-3-methylimidazolium, pentamethylimidazolium, and 1,3-dimethyl-2,4,5-triphenylimidazolium, were investigated. Their structures were established by single-crystal X-ray diffraction. The compounds are paramagnetic with effective magnetic moments in the range of those expected by the number of unpaired spins of the chromium(III) ion. All melting points are above 100 °C, which prevents us from calling these compounds "ionic liquids". Nevertheless, they are low for salts of this constitution and may be useful for molten salt reactions. Cyclic voltammetry measurements show no reversible electron-transfer steps.

Perinatal management of trisomy 18: a survey of obstetricians in Australia, New Zealand and the UK

OBJECTIVE

The objective of this study was to explore the attitudes of obstetricians in Australia, New Zealand and the UK towards prenatally diagnosed trisomy 18 (T18).

METHOD

Obstetricians were contacted by email and invited to participate in an anonymous electronic survey.

RESULTS

Survey responses were obtained from 1018/3717 (27%) practicing obstetricians/gynaecologists. Most (60%) had managed a case of T18 in the last 2 years. Eighty-five per cent believed that T18 was a 'lethal malformation', although 38% expected at least half of liveborn infants to survive for more than 1 week. Twenty-one per cent indicated that a vegetative existence was the best developmental outcome for surviving children. In a case of antenatally diagnosed T18, 95% of obstetricians would provide a mother with the option of termination. If requested, 99% would provide maternal-focused obstetric care (aimed at maternal wellbeing rather than fetal survival), whereas 80% would provide fetal-oriented obstetric care (to maximise fetal survival). Twenty-eight per cent would never discuss the option of caesarean; 21% would always discuss this option. Management options, attitudes and knowledge of T18 were associated with location, practice type, gender and religion of obstetricians.

CONCLUSION

There is variability in obstetricians' attitudes towards T18, with significant implications for management of affected pregnancies.

Signal transduction of erythropoietin in endothelial cells

Erythropoietin (EPO) induces endothelin expression in endothelial cells (EC) and has angiogenic effects. We investigated the intracellular signal transduction of EPO in EC and tested the hypothesis that the proliferative effects of EPO may be mediated by cytosolic calcium, changes in intracellular pH, or tyrosine phosphorylation. Cytosolic calcium and pH were measured with fura-2 and BCECF. Protein phosphorylation was assessed with 32P-labeled EC and two-dimensional (2D) gel chromatography. Tyrosine phosphorylation was measured using specific antityrosine antibodies and confocal microscopy. Proliferation was measured by thymidine incorporation and cell count. No effects of EPO on cytosolic calcium and pH were observed. In contrast, erythropoietin increased phosphorylation of 94, 70, 42, 40, 29 and 25 kDa proteins at five minutes and 60 minutes. Most of the early proteins were tyrosine phosphorylated. Confocal microscopy showed cytosolic as well as membrane-bound tyrosine phosphorylation in resting cells and an EPO-induced translocation of immunoreactivity to the nucleus. Immunostaining for the transcription factor STAT-5 showed that EPO induced a nuclear translocation of STAT-5. EPO 0.5, 2, and 4 U/ml increased proliferation, an effect that was prevented by incubation with the tyrosine kinase inhibitor genistein. We conclude that EPO induces proliferation in EC initially via tyrosine phosphorylation of six distinct proteins, and that the phosphorylation and nuclear translocation of the transcription factor STAT-5 is important for the effects of EPO on EC.

[Expert assessment of chronic venous insufficiency]

In the expertise of a chronic venous insufficiency kind and stage of the venous disease must be proved as objectively as possible. The diagnostic demands in the individual step programmes serve for the exact assessment of the remaining part of efficiency. The criteria of valuation are summarized, in which case we also deal with several possibilities of combination with other vascular diseases. The expert opinion of an accident is discussed. References to the inability to work, rating of nursing money, increased material benefit in impairments of health and to the acknowledgement of an identity card for injured persons supplement the statements.

[Current therapy of chronic arterial occlusive diseases of the lower extremities]

Angiologists, vascular surgeons, and angiographers inform about the actual state of the therapy of the arterial occlusive diseases of the legs. The degree I of therapy comprises the conservative treatment for the improvement of the macrocirculation and the normalisation of the disturbed microcirculation, taking into particular consideration the therapy with antiviscositant drugs. The main chapter ends with the possibilities of the influence on the arteriosclerotic vascular processes as well as with the necessary rehabilitative measures. In the paragraph about the degree II of therapy the indications, contraindications, methods and results of the isolated and combined percutaneous transluminal angioplasty, the systemic and local fibrinolysis as well as the reconstructive vascular operations are represented.

[Whole blood viscosity in patients with acral arterial occlusive diseases and their modification by rheologically active drugs]

Measurements of the whole-blood viscosity in patients with organic and functional disturbances of the acral blood supply were performed. In comparison with the whole-blood viscosity in normal persons patients with acral occlusive diseases showed a significantly increased viscosity. On the other hand, in patients with functional disturbances of the acral blood supply no differences could be established. In a therapy study the good efficacy of rheologically effective medicaments could be demonstrated particularly as combination therapy of pentoxifylline, acetylsalicylic acid and tolazoline in patients with acral occlusive diseases. These medicaments should by all means be used together with the basic therapy. In functional disturbances of the blood supply should predominantly be maintained physiotherapeutic methods of treatment.

[Theses on the evaluation of arterial circulatory disorders of the extremities]

In an expert opinion of disturbance of the arterial blood supply concerning invalidity the vascular disease must be proved with sufficient ascertainment as well as the functional capacity remained must be estimated. Every expert opinion should contain as far as possible concrete data already in the angiologic-diagnostic minimum programme. In problematic cases supplementations by a special angiological diagnostics are necessary. The criteria of evaluation of arterial obstructive diseases for an expert opinion concerning invalidity are also summarized in theses. Also the relations between disturbances of the peripheral blood supply and effects of injury are discussed. The paper concludes with references to the acknowledgement of a disability card in arterial obstructive diseases and to the motor-car driving ability of patients with vascular diseases.

Species-dependent variables in blood cerebrospinal fluid barrier for proteins

Cerebrospinal fluid/plasma concentration quotients for immunoglobulin G (I) and albumin (A) were determined in guinea pigs. Age and sex-dependent influences on these quotients (I/A) were analyzed and compared with the values for human lumbar, cisternal and ventricular cerebrospinal fluid. The ratio I/A, which characterizes the molecular size-dependent selectivity of the blood cerebrospinal fluid barrier function for proteins, was found to be a constant in a single species, but showed marked interspecies differences.

[Clinical aspects and differential diagnosis of primary acral circulatory disorders]

The disturbances of the primary acral blood supply show fluent transitions from the angiopathic position of the reaction over the digitus mortuus to Raynaud's disease. The functional vascular disturbances at stage II of Raynaud's disease change even to an organic arterial process. The various clinical pictures of the angioneuropathies can be differentiated in every ambulatory surgery in the majority of cases with the help of an aimed anamnesis on the basis of the clinical findings and by simple functional tests. When there are facts unclear, various apparative methods of diagnostics or the acral arteriography must be used.

[Significance and taxonomy of functional and organic acral circulatory disorders and cutaneous microangiopathies]

Acral disturbances of the blood supply and cutaneous microangiopathies may be associated with functional as well as with organic vascular disturbances. The primary angiopathies are independent clinical pictures, the causes of which are still unknown. In numerous diseases secondary forms of the disturbances of the acral blood supply and the microangiopathies can occur. The systematics represented corresponds to the relevant ambulatory view-points. On the basis of the frequency of several clinical pictures is referred to the importance for the policlinical practice.

[Conservative therapy of acral circulatory disorders and cutaneous microangiopathies]

Despite the different pathological value of disturbances of the acral blood supply and cutaneous microangiopathies there is a need of treatment of these clinical pictures. It can extend from a simple therapeutic consultation of the patient up to the complex use of adequate rules of life, of physiotherapeutic and pharmacological measures. Under this angle of view the treatment of the angiopathic reactive position, of the digitus mortuus and Raynaud's disease is demonstrated. Of particular interest is the use of new antiviscositants in organic disturbances of the acral blood supply. The treatment of the microangiopathies should also be derived from a complex way of consideration in the sense of therapy step programmes. Taking into consideration the severity of the clinical picture the therapy of acrocyanosis, erythrocyanosis drurum puellarum, cutis marmorata, erythromelalgy, livedo racemosa, perniones, hypertensive and diabetic microangiopathy is discussed. In the secondary forms of the disturbances of the acral blood supply the treatment of the basic disease is in the foreground. The accompanying disturbances of the blood circulation may on principle be treated by means of the same measures, which are promising in the primary clinical pictures.

[Prevention and therapy of disorders of purine metabolism]

To the most important prophylactic measures for the prevention of a disturbance of the purine metabolism belong the normalisation of the body-weight, a mixed diet without protein carriers containing much purine, a regular physical activity, a life without hectic conditions as well as without an excess of conflict situations and a moderate taking of alcohol. These recommendations are of particular importance for patients endangered by gout. In patients with hyperuricaemia they form the basic treatment for the prevention of a uric arthritis, a urate nephrolithiasis and a gouty nephropathy. The clinical and paraclinical results of the directives must be continuously tested with regard to the effectiveness. To the comprehensive prophylaxis also belong the preventive measures against an associated disturbance of an associated disturbance of metabolism or concomitant disease. An additional medicamentous therapy is necessary, when the success of the basic therapy is insufficient and there are already organ manifestations of a disturbance of the purine metabolism. The application of antihyperuraemic drugs corresponding to types should be performed by uricostatic drugs, uricosuric drugs and citric acid-citrate mixtures. The approach according to a 3-step-programme is most useful. In the treatment of the concomitant diseases certain preventive measures are to be taken into consideration. The therapy of an acute attack of gout is at present without any essential problems. Patients with disturbances of the purine metabolism need a permanent care by the physician.

[Epidemiology of hyperuricemia and gout]

Also in the GDR during the last 10 years the frequency of the disturbances of the purine metabolism increased. With a rate of prevalence of about 20% this anomaly of metabolism reaches the highest percentage of the metabolic disturbances. The increasing accumulation of the disturbances of the purine metabolism on account of complex examinations depends above all on the changed eating and drinking habits of the population. Also influences on body-weight, blood pressure and bodily activities are to be taken into consideration. Sex, age and genetic loads belong to the non-correctable factors of influence. The influences of methodical problems must particularly be taken into consideration in long-term studies. The accumulation of uric arthritis is still relatively small in the GDR in contrast to other industrial countries. However, in our county exact epidemiologic investigations are still necessary.

[Extraarticular diseases and findings in gout]

Disturbances of the renal function, urolithiasis and hypertension are observed in a high percentage already in the asymptomatic stage of the primary hyperuricaemia. They determine above all the fate of the patient with gout. In primary uric arthritis over-accidentally frequently obesity, steatosis hepatis, hyperlipoproteinaemias, manifest diabetes mellitus and premature arteriosclerosis are found, without up to now proving a causal connection. Also these diseases often coin the clinical picture and demand particular attention in the diagnostics of patients with gout.

[Conservative treatment of arteriosclerosis obliterans]

The conservative therapy of the arteriosclerotic obstructive disease demands a complex approach. The basis therapy, the symptomatic treatment of the haemodynamics of the extremity with ill vessels, the pathogenetically oriented therapy as well as the treatment of other localisations of the arteriosclerosis should be used combined. At stage III and IV additional measures, such as combat against pain, therapy with antibiotics and local treatment of tissue lesions are necessary. The results of the therapy should be critically tested not only on the basis of the clinical picture, but also on the basis of the course of the vascular processes.

[Therapy of gout]

The therapy of gout is discussed taking into consideration the concomitant diseases occurring significantly frequently in patients with gout: Hypertension, uric acid-nephrolithiasis, hyperlipoproteinaemia, obesity, premature arteriosclerosis as well as diabetes mellitus. In contrast to other opinions the authors are of the opinion that the dietetic treatment is furthermore of essential importance. It is referred to the still allowed sufficiently great number in the supply of nourishment, in which cases, however, the limitations in the supply of calories, protein or purin bodies, respectively, lipid and carbohydrate do not remain unmentioned. The propositions for the medicamentous treatment essentially correspond to the central therapeutic recommendations. For the acute attack of gout, however, following to the international experiences, the colchicine therapy is more emphasized again. The medicamentous therapy of the asymptomatic hyperuricaemia is to be included into the considerations after full exhaustion of all dietetic and other possibilities in constant increase of the serum-uric acid-level more than 8 mg/dl.

[Uncharacteristic symptoms of the motor apparatus in gout]

Gout may present in such atypical forms as "primary-chronic", "masked", or "asymptomatic gout at all stages affecting almost any joint. These uncharacteristic presentations were found in 22 out of 124 patients observed. The disease of 4 patients is described as casuistics. Important conclusions of practical use for early diagnosis and early treatment are drawn. Every arthropathy in a male where the diagnosis is not certain, must be suspected as being due to gout. The diagnosis can be assured by detecting urate deposits in the tissue. Determinations of the serum uric acid level can only be indicative since they are subject to a variety of influences. In early disease the x-ray appearances may be described as normal; in later disease as "degenerative" in the joints or in the vertebral column. In an acute relapse the colchicine-test is of high specifity, but its interpretation may be difficult in the primary chronic forms. The other clinical manifestations of the gout syndrome are of high value for the selection of patients in whom urate deposits in the tissue must be sought.

[Relationship between disorders of the purine and carbohydrate metabolism]

Disturbances of the carbohydrate metabolism more frequently appear in patients suffering from gout. On the other hand, in contrast to older data, in diabetics disturbances of the purin metabolism are also frequently found. Under the momentaneous enviromental factors and forming of life genetic prediapositions may lead to the manifestations of the two metabolic disturbances.