Age is the main determinant of COVID-19 related in-hospital mortality with minimal impact of pre-existing comorbidities, a retrospective cohort study.

BACKGROUND: Age and comorbidities increase COVID-19 related in-hospital mortality risk, but the extent by which comorbidities mediate the impact of age remains unknown. METHODS: In this multicenter retrospective cohort study with data from 45 Dutch hospitals, 4806 proven COVID-19 patients hospitalized in Dutch hospitals (between February and July 2020) from the CAPACITY-COVID registry were included (age 69[58-77]years, 64% men). The primary outcome was defined as a combination of in-hospital mortality or discharge with palliative care. Logistic regression analysis was performed to analyze the associations between sex, age, and comorbidities with the primary outcome. The effect of comorbidities on the relation of age with the primary outcome was evaluated using mediation analysis. RESULTS: In-hospital COVID-19 related mortality occurred in 1108 (23%) patients, 836 (76%) were aged ≥70 years (70+). Both age 70+ and female sex were univariably associated with outcome (odds ratio [OR]4.68, 95%confidence interval [4.02-5.45], OR0.68[0.59-0.79], respectively;both p<  0.001). All comorbidities were univariably associated with outcome (p<0.001), and all but dyslipidemia remained significant after adjustment for age70+ and sex. The impact of comorbidities was attenuated after age-spline adjustment, only leaving female sex, diabetes mellitus (DM), chronic kidney disease (CKD), and chronic pulmonary obstructive disease (COPD) significantly associated (female OR0.65[0.55-0.75], DM OR1.47[1.26-1.72], CKD OR1.61[1.32-1.97], COPD OR1.30[1.07-1.59]). Pre-existing comorbidities in older patients negligibly (<6% in all comorbidities) mediated the association between higher age and outcome. CONCLUSIONS: Age is the main determinant of COVID-19 related in-hospital mortality, with negligible mediation effect of pre-existing comorbidities. TRIAL REGISTRATION: CAPACITY-COVID ( NCT04325412 ).

Electrocardiogram-based mortality prediction in patients with COVID-19 using machine learning.

BACKGROUND AND PURPOSE: The electrocardiogram (ECG) is frequently obtained in the work-up of COVID-19 patients. So far, no study has evaluated whether ECG-based machine learning models have added value to predict in-hospital mortality specifically in COVID-19 patients. METHODS: Using data from the CAPACITY-COVID registry, we studied 882 patients admitted with COVID-19 across seven hospitals in the Netherlands. Raw format 12-lead ECGs recorded within 72 h of admission were studied. With data from five hospitals (n = 634), three models were developed: (a) a logistic regression baseline model using age and sex, (b) a least absolute shrinkage and selection operator (LASSO) model using age, sex and human annotated ECG features, and (c) a pre-trained deep neural network (DNN) using age, sex and the raw ECG waveforms. Data from two hospitals (n = 248) was used for external validation. RESULTS: Performances for models a, b and c were comparable with an area under the receiver operating curve of 0.73 (95% confidence interval [CI] 0.65-0.79), 0.76 (95% CI 0.68-0.82) and 0.77 (95% CI 0.70-0.83) respectively. Predictors of mortality in the LASSO model were age, low QRS voltage, ST depression, premature atrial complexes, sex, increased ventricular rate, and right bundle branch block. CONCLUSION: This study shows that the ECG-based prediction models could be helpful for the initial risk stratification of patients diagnosed with COVID-19, and that several ECG abnormalities are associated with in-hospital all-cause mortality of COVID-19 patients. Moreover, this proof-of-principle study shows that the use of pre-trained DNNs for ECG analysis does not underperform compared with time-consuming manual annotation of ECG features.

Dissecting the transcriptome in cardiovascular disease.

The human transcriptome comprises a complex network of coding and non-coding RNAs implicated in a myriad of biological functions. Non-coding RNAs exhibit highly organized spatial and temporal expression patterns and are emerging as critical regulators of differentiation, homeostasis, and pathological states, including in the cardiovascular system. This review defines the current knowledge gaps, unmet methodological needs, and describes the challenges in dissecting and understanding the role and regulation of the non-coding transcriptome in cardiovascular disease. These challenges include poor annotation of the non-coding genome, determination of the cellular distribution of transcripts, assessment of the role of RNA processing and identification of cell-type specific changes in cardiovascular physiology and disease. We highlight similarities and differences in the hurdles associated with the analysis of the non-coding and protein-coding transcriptomes. In addition, we discuss how the lack of consensus and absence of standardized methods affect reproducibility of data. These shortcomings should be defeated in order to make significant scientific progress and foster the development of clinically applicable non-coding RNA-based therapeutic strategies to lessen the burden of cardiovascular disease.

Mutations in LZTR1 drive human disease by dysregulating RAS ubiquitination.

The leucine zipper-like transcriptional regulator 1 (LZTR1) protein, an adaptor for cullin 3 (CUL3) ubiquitin ligase complex, is implicated in human disease, yet its mechanism of action remains unknown. We found that Lztr1 haploinsufficiency in mice recapitulates Noonan syndrome phenotypes, whereas LZTR1 loss in Schwann cells drives dedifferentiation and proliferation. By trapping LZTR1 complexes from intact mammalian cells, we identified the guanosine triphosphatase RAS as a substrate for the LZTR1-CUL3 complex. Ubiquitome analysis showed that loss of Lztr1 abrogated Ras ubiquitination at lysine-170. LZTR1-mediated ubiquitination inhibited RAS signaling by attenuating its association with the membrane. Disease-associated LZTR1 mutations disrupted either LZTR1-CUL3 complex formation or its interaction with RAS proteins. RAS regulation by LZTR1-mediated ubiquitination provides an explanation for the role of LZTR1 in human disease.

Elastic properties of the nematic phase in hard ellipsoids of short aspect ratio.

We present a Monte Carlo simulation study of suspensions of hard ellipsoids of revolution. Based on the spatial fluctuations of the orientational order, we have computed the Frank elastic constants for prolate and oblate ellipsoids and compared them to the affine transformation model. The affine transformation model predicts the right order of magnitude of the twist and bend constant but not of the splay constant. In addition, we report the observation of a stable nematic phase at an aspect ratio as low as 2.5.

RNA Profiling in Human and Murine Transplanted Hearts: Identification and Validation of Therapeutic Targets for Acute Cardiac and Renal Allograft Rejection.

Acute cellular rejection (ACR) is the adverse response of the recipient's immune system against the allogeneic graft. Using human surveillance endomyocardial biopsies (EMBs) manifesting ACR and murine allogeneic grafts, we profiled implicated microRNAs (miRs) and mRNAs. MiR profiling showed that miR-21, -142-3p, -142-5p, -146a, -146b, -155, -222, -223, and -494 increased during ACR in humans and mice, whereas miR-149-5p decreased. mRNA profiling revealed 70 common differentially regulated transcripts, all involved in immune signaling and immune-related diseases. Interestingly, 33 of 70 transcripts function downstream of IL-6 and its transcription factor spleen focus forming virus proviral integration oncogene (SPI1), an established target of miR-155, the most upregulated miR in human EMBs manifesting rejection. In a mouse model of cardiac transplantation, miR-155 absence and pharmacological inhibition attenuated ACR, demonstrating the causal involvement and therapeutic potential of miRs. Finally, we corroborated our miR signature in acute cellular renal allograft rejection, suggesting a nonorgan specific signature of acute rejection. We concluded that miR and mRNA profiling in human and murine ACR revealed the shared significant dysregulation of immune genes. Inflammatory miRs, for example miR-155, and transcripts, in particular those related to the IL-6 pathway, are promising therapeutic targets to prevent acute allograft rejection.

Prevalence and prognostic relevance of cardiac involvement in ANCA-associated vasculitis: eosinophilic granulomatosis with polyangiitis and granulomatosis with polyangiitis.

BACKGROUND: To investigate the prevalence and prognostic relevance of cardiac involvement in an ANCA-associated vasculitis (AAV) population of eosinophilic granulomatosis with polyangiitis (EGPA) and granulomatosis with polyangiitis (GPA) patients. METHODS: Prospective cohort study of fifty EGPA and forty-one GPA patients in sustained remission without previous in-depth cardiac screening attending our clinical immunology outpatient department. Cardiac screening included clinical evaluation, ECG, 24-hour Holter registration, echocardiography and cardiac magnetic resonance imaging (CMR) with coronary angiography and endomyocardial biopsy upon indication. Fifty age-, sex- and cardiovascular risk factor-matched control subjects were randomly selected from a population study. Long-term outcome was assessed using all-cause and cardiovascular mortality. RESULTS: A total of 91 AAV-patients (age 60±11, range 63-87years) were compared to 50-matched control subjects (age 60±9years, range 46-78years). ECG and echocardiography demonstrated cardiac abnormalities in 62% EGPA and 46% GPA patients vs 20% controls (P<0.001 and P=0.014, respectively). A total of 69 AAV-patients underwent additional CMR, slightly increasing the prevalence of cardiac involvement to 66% in EGPA and 61% in GPA patients. After a mean follow-up of 53±18months, presence of cardiac involvement using ECG and echocardiography in AAV-patients showed increased all-cause and cardiovascular mortality (Log-rank P=0.015 and Log-rank P=0.021, respectively). CONCLUSION: Cardiac involvement in EGPA and GPA patients with sustained remission is high, even if symptoms are absent and ECG is normal. Moreover, cardiac involvement is a strong predictor of (cardiovascular) mortality. Therefore, risk stratification using cardiac imaging is recommended in all AAV-patients, irrespective of symptoms or ECG abnormalities.

Right ventricular function in dilated cardiomyopathy and ischemic heart disease: assessment with non-invasive imaging.

BACKGROUND: Dilated cardiomyopathy and ischaemic heart disease can both lead to right ventricular (RV) dysfunction. Direct comparisons of the two entities regarding RV size and function using state-of-the-art imaging techniques have not yet been performed. We aimed to determine RV function and volume in dilated cardiomyopathy and ischaemic heart disease in relation to left ventricular (LV) systolic and diastolic function and systolic pulmonary artery pressure. METHODS AND RESULTS: A well-characterised group (cardiac magnetic resonance imaging, echocardiography, coronary angiography and endomyocardial biopsy) of 46 patients with dilated cardiomyopathy was compared with LV ejection fraction (EF)-matched patients (n = 23) with ischaemic heart disease. Volumes and EF were determined with magnetic resonance imaging, diastolic LV function and pulmonary artery pressure with echocardiography. After multivariable linear regression, four factors independently influenced RVEF (R(2) = 0.51, p < 0.001): LVEF (r = 0.54, p < 0.001), ratio of peak early and peak atrial transmitral Doppler flow velocity as measure of LV filling pressure (r = - 0.52, p < 0.001) and tricuspid regurgitation flow velocity as measure of pulmonary artery pressure (r = - 0.38, p = 0.001). RVEF was significantly worse in patients with dilated cardiomyopathy compared with ischaemic heart disease: median 48 % (interquartile range (IQR) 37-55 %) versus 56 % (IQR 48-63 %), p < 0.05. CONCLUSIONS: In patients with dilated cardiomyopathy and ischaemic heart disease, RV function is determined by LV systolic and diastolic function, the underlying cause of LV dysfunction, and pulmonary artery pressure. It was demonstrated that RV function is more impaired in dilated cardiomyopathy.

Diagnostic approach of myocarditis: strike the golden mean.

Myocarditis is a challenging diagnosis due to the extreme diversity of clinical manifestations. The actual incidence of myocarditis is also difficult to determine as endomyocardial biopsy (EMB), the diagnostic gold standard, is used infrequently. Nevertheless, in up to 30 % of patients with biopsy-proven myocarditis, progression to dilated cardiomyopathy (DCM) can occur and is associated with a poor prognosis. Recent position statements of the European Society of Cardiology (ESC) and the American Heart Association vary widely with regard to indications for performing an EMB in these patients. This makes decision-making, in particular for general practitioners (GPs) and regional hospitals, difficult and unclear. Therefore, we will present a short summary of the ESC Working Group on Myocardial and Pericardial Diseases statement and our suggestions for GPs and regional hospitals for the diagnostic approach in patients with suspected myocarditis.

Idiopathic dilated cardiomyopathy: possible triggers and treatment strategies.

Despite recent advances in the management of patients with heart failure, morbidity and mortality rates remain high. Common causes of heart failure are ischaemic heart disease, uncontrolled hypertension and valvular disease. However, in up to 50 % of the cases its exact cause remains initially unknown; this condition is called idiopathic dilated cardiomyopathy (DCM). Improved diagnostic methods, most notably the advancements in molecular and immunohistological biopsy techniques and genetic research, have endorsed a new era in the diagnosis and classification of patients with idiopathic DCM. These insights have led to novel aetiology-based treatment strategies and improved outcome. The present article will briefly discuss all causes of DCM with a special focus on inflammatory- and virus-mediated forms of DCM.

Giant cell myocarditis triggered by a parvovirus B19 infection.

Giant cell myocarditis (GCM) is an uncommon inflammatory heart disease with a rapid progression and a devastating outcome. Its exact cause is unknown, but it has been associated with various inflammatory and autoimmune disorders. The authors report a case where GCM is triggered by a parvovirus B19 (PVB19) infection.

Inflammation and cardiac remodeling during viral myocarditis.

Acute viral myocarditis is the main cause of cardiac failure in young patients and accounts for up to 60% of "idiopathic" dilated cardiomyopathy. The clinical course of viral myocarditis is mostly insidious with limited cardiac inflammation and dysfunction. However, overwhelming inflammation may occur in a subset of patients, leading to fulminant cardiac injury, whereas others develop chronic heart failure due to autoimmune myocarditis. Today, little effective treatment exists for patients, apart from general supportive therapy and antifailure regimens. Urokinase-type plasminogen activator (u-PA) and matrix metalloproteinases (MMP) have been implicated in cardiac inflammation, matrix remodeling, and wound healing after cardiac injury. The present review will assess the mechanism by which these proteinases mediate cardiac dilatation, fibrosis, and dysfunction after cardiac stress or injury, in order to understand how inhibition of proteinases may provide a novel therapeutic tool to prevent cardiac dilatation and failure during viral myocarditis.

Replacement of the muscle-specific sarcoplasmic reticulum Ca(2+)-ATPase isoform SERCA2a by the nonmuscle SERCA2b homologue causes mild concentric hypertrophy and impairs contraction-relaxation of the heart.

The cardiac sarco(endo)plasmic reticulum Ca(2+)-ATPase gene (ATP2A2) encodes the following two different protein isoforms: SERCA2a (muscle-specific) and SERCA2b (ubiquitous). We have investigated whether this isoform specificity is required for normal cardiac function. Gene targeting in mice successfully disrupted the splicing mechanism responsible for generating the SERCA2a isoform. Homozygous SERCA2a(-/-) mice displayed a complete loss of SERCA2a mRNA and protein resulting in a switch to the SERCA2b isoform. The expression of SERCA2b mRNA and protein in hearts of SERCA2a(-/-) mice corresponded to only 50% of wild-type SERCA2 levels. Cardiac phospholamban mRNA levels were unaltered in SERCA2a(-/-) mice, but total phospholamban protein levels increased 2-fold. The transgenic phenotype was characterized by a approximately 20% increase in embryonic and neonatal mortality (early phenotype), with histopathologic evidence of major cardiac malformations. Adult SERCA2a(-/-) animals (adult phenotype) showed a reduced spontaneous nocturnal activity and developed a mild compensatory concentric cardiac hypertrophy with impaired cardiac contractility and relaxation, but preserved beta-adrenergic response. Ca(2+) uptake levels in SERCA2a(-/-) cardiac homogenates were reduced by approximately 50%. In isolated cells, relaxation and Ca(2+) removal by the SR were significantly reduced. Comparison of our data with those obtained in mice expressing similar cardiac levels of SERCA2a instead of SERCA2b indicate the importance of the muscle-specific SERCA2a isoform for normal cardiac development and for the cardiac contraction-relaxation cycle.

Deletion of the hypoxia-response element in the vascular endothelial growth factor promoter causes motor neuron degeneration.

Hypoxia stimulates angiogenesis through the binding of hypoxia-inducible factors to the hypoxia-response element in the vascular endothelial growth factor (Vegf) promotor. Here, we report that deletion of the hypoxia-response element in the Vegf promotor reduced hypoxic Vegf expression in the spinal cord and caused adult-onset progressive motor neuron degeneration, reminiscent of amyotrophic lateral sclerosis. The neurodegeneration seemed to be due to reduced neural vascular perfusion. In addition, Vegf165 promoted survival of motor neurons during hypoxia through binding to Vegf receptor 2 and neuropilin 1. Acute ischemia is known to cause nonselective neuronal death. Our results indicate that chronic vascular insufficiency and, possibly, insufficient Vegf-dependent neuroprotection lead to the select degeneration of motor neurons.

Recombinant staphylokinase variants with reduced antigenicity due to elimination of B-lymphocyte epitopes.

Site directed mutagenesis (350 variants) of recombinant staphylokinase (SakSTAR), a potent fibrin-selective thrombolytic agent, was undertaken in order to reduce its antigenicity while maintaining its potency. Variants with K35A, (ie, Lys[K] in position 35 substituted with Ala[A]), E65D or E65Q, K74R or K74Q, E80A+D82A, K130T, and K135R displayed increased enzymatic activity or reduced binding of human staphylokinase-specific antibodies. Additive mutagenesis identified 8 variants with intact thrombolytic potencies, which absorbed down to less than a third of SakSTAR-specific antibodies. Intra-arterial administration in 61 patients with peripheral arterial occlusion caused no significant allergic reactions. Median neutralizing antibody titers (with 15 to 85 percentiles), expressed as microgram (microg) compound neutralized per milliliter plasma, were 4.4 (0.3 to 49) for the variants, compared with 12 (4 to 100) in 70 patients given wild-type SakSTAR (P =.002 by Mann-Whitney rank sum test). Overt neutralizing antibody induction (more than 5 microg compound neutralized per milliliter plasma) was observed in 57 of 70 patients (81%) given wild-type SakSTAR, but only in 28 of 60 patients (47%) treated with variants (P <.0001 by Fisher exact test). On the basis of this study, the variant SakSTAR (K35A, E65Q, K74R, D82A, S84A, T90A, E99D, T101S, E108A, K109A, K130T, K135R) (code SY155) has been selected for further clinical development. (Blood. 2000;96:1425-1432)

Disruption of the plasminogen gene in mice abolishes wound healing after myocardial infarction.

The plasminogen system plays an important role in the proteolytic degradation of extracellular matrices during wound healing. In the present study we investigated the impact of the plasminogen system on cardiac wound healing and function after myocardial infarction. Myocardial infarction was induced in plasminogen-deficient mice (Plg-/-) and in wild-type controls (Plg+/+). Structural analysis 1, 2, and 5 weeks after infarction revealed that infarct healing was virtually abolished in Plg-/- mice, indicating that the plasminogen system is required for the repair process of the heart after infarction. In the absence of plasminogen, inflammatory cells did not migrate into the infarcted myocardium. Necrotic cardiomyocytes were not removed and the formation of granulation tissue and fibrous tissue did not occur. In these non-healing infarcted hearts, LV dilatation was not altered. In addition, gelatinolytic activity of MMP-2 and MMP-9 was depressed in the Plg-/- infarcted hearts, suggesting that the plasmin effect on infarct healing may be mediated by MMPs. Surprisingly, cardiac function was only attenuated to a rather small extent in the Plg-/- infarcted mice when compared to the wild-types. This study provides direct prove that plasmin-mediated proteolysis plays a central role in cardiac wound healing after myocardial infarction in mice.

Outcome and one year follow-up of intra-arterial staphylokinase in 191 patients with peripheral arterial occlusion.

Wild-type or equipotent variants of recombinant staphylokinase (rSak) were given intra-arterially (as a 2 mg bolus injection followed by an infusion of 1 mg/h or 0.5 mg/h overnight, with concomitant heparin [1000 IU/h]) to 191 patients of less than 80 years (62 +/- 1 years, mean +/- SEM), with a peripheral arterial occlusion (PAO) of less than 120 days (mean 14 +/- 1 days, median 11 days, 5 to 95 percentiles 3 to 30 days). Ninety nine patients presented with acute or subacute ischemia, 57 with severe claudication, 33 with chronic rest pain and 2 with gangrene. Occlusion occurred in 122 native arteries and in 69 grafts. Revascularization was complete in 83 percent (158/191), partial in 13 percent (24/191) and absent in 4 percent (7/191) after administration of 12 +/- 0.5 mg rSak over 14 +/- 0.7 h. Complete revascularization of acute occlusions of popliteal or more distal arteries was less frequent (60 percent, 15/25) than of acute occlusions of more proximal native arteries (95 percent, 37/39, p <0.001) or grafts (89 percent, 50/56, p = 0.005). Additional endovascular procedures were performed in 47 percent and subsequent elective bypass surgery in 23 percent of patients. Major bleeding occurred in 12 percent (23/191), one month mortality was 3.1 percent (6/191) and one year mortality was 6.9 percent (12/174). However, four patients (2.1 percent) had an intracranial bleeding following therapy: a 85 year old woman with severe diabetic arteriopathy, who was included in violation of the protocol, a 79 and a 74-year-old woman and a 74-year-old man, all with severe hypertension and limb threatening ischemia; these four patients died within two months after treatment. Amputations were performed within the first year in 16 of 162 surviving patients (9.8 percent): in 7 percent (7/96) with an occluded native artery and 14 percent (9/66) with an occluded graft (p = 0.19). No significant difference in lysis rate, one month mortality or one year amputation-free survival was observed in occlusions of recent onset (< or =14 days, n = 126) as compared to occlusions of longer duration (>14 days, n = 65). Treatment was interrupted prematurely in 4 patients because of a suspected allergic reaction. Fibrinogen levels remained unaffected during treatment (3.3 +/- 0.1 g/l before vs. 3.3 +/- 0.1 g/l after infusion, n = 167). In conclusion, rSak appears to be a highly effective thrombolytic agent in patients with PAO, resulting in a low one month mortality (3.1 percent) and a high one year amputation free survival (84 percent), with an acceptable incidence of major bleedings, but with occasional fatal intracranial hemorrhages.

Inhibition of plasminogen activators or matrix metalloproteinases prevents cardiac rupture but impairs therapeutic angiogenesis and causes cardiac failure.

Cardiac rupture is a fatal complication of acute myocardial infarction lacking treatment. Here, acute myocardial infarction resulted in rupture in wild-type mice and in mice lacking tissue-type plasminogen activator, urokinase receptor, matrix metalloproteinase stromelysin-1 or metalloelastase. Instead, deficiency of urokinase-type plasminogen activator (u-PA-/-) completely protected against rupture, whereas lack of gelatinase-B partially protected against rupture. However, u-PA-/- mice showed impaired scar formation and infarct revascularization, even after treatment with vascular endothelial growth factor, and died of cardiac failure due to depressed contractility, arrhythmias and ischemia. Temporary administration of PA inhibitor-1 or the matrix metalloproteinase-inhibitor TIMP-1 completely protected wild-type mice against rupture but did not abort infarct healing, thus constituting a new approach to prevent cardiac rupture after acute myocardial infarction.

Feasibility study of catheter-directed thrombolysis with recombinant staphylokinase in deep venous thrombosis.

The feasibility of catheter-directed thrombolysis with recombinant staphylokinase was evaluated in six selected patients with deep vein thrombosis. The patients underwent intrathrombus infusion of recombinant staphylokinase (2 mg bolus followed by a continuous infusion of 1 mg/h). Heparin was given via the catheter as a bolus (5000 U) and as a continuous infusion (1000 U/h). Complete lysis was obtained in five patients and partial lysis in one patient. Complications consisted of minor bleeding in four subjects. Symptomatic reocclusion occurred in one. Debulking of the thrombus mass by a high speed rotating impeller (n = 1) and stenting (n = 3) were used as additional interventions. An underlying anatomical abnormality was present in two patients. Long term follow up revealed normal patency in all patients and normal valve function in four patients. Symptomatic venous insufficiency with valve dysfunction was present in the two with a second thrombotic episode. Thus catheter-directed infusion of recombinant staphylokinase in patients with deep vein thrombosis appears feasible and may be associated with a high frequency of thrombolysis. Larger studies to define the clinical benefit of this treatment appear to be warranted.