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.

The Netherlands Sports Cardiology Map: a step towards sports cardiology network medicine for patient and athlete care.

Sports cardiology is a rapidly evolving subspecialty of cardiology, with a growing demand for expertise. To improve patient care, clinicians, patients, and athletes (recreational to elite) should be able to easily identify specialised care pathways, expertise centres and clinicians with sports cardiology expertise. To this purpose, several international societies and organisations recommend establishing a local and national sports cardiology infrastructure. We therefore aimed to establish The Netherlands Sports Cardiology Map. We conducted a web-based survey, which was published on the Netherlands Society of Cardiology home page (2019-2020) and in which each cardiology department or clinic was asked to provide information on sports cardiology expertise and the current infrastructure. Of the 46 respondent centres, 28 (61%) reported that they had expertise in sports cardiology, of which 22 (79%) had specific expertise in one or more specific types of sports. Integrated multidisciplinary meetings were reported by 43% of the centres (n = 12/28). Only two centres reported ongoing research projects that had been approved by an institutional review board. The Netherlands Sports Cardiology Map is an important step towards improving the existing infrastructure and developing network medicine for sports cardiology.

Heterozygous loss of Rbm24 in the adult mouse heart increases sarcomere slack length but does not affect function.

RNA-binding proteins are key regulators of post-transcriptional processes such as alternative splicing and mRNA stabilization. Rbm24 acts as a regulator of alternative splicing in heart and skeletal muscle, and is essential for sarcomere assembly. Homozygous inactivation of Rbm24 in mice disrupts cardiac development and results in embryonic lethality around E12.5. In the present study, we generated somatic Rbm24 knockout (KO) mice and investigated the effects of reduced levels of Rbm24 in the adult heart. Due to the embryonic lethality of Rbm24 KO mice, we examined cardiac structure and function in adult Rbm24 heterozygotes (HETs). Rbm24 protein expression was 40% downregulated in HET hearts compared to WT hearts. Force measurements on isolated membrane-permeabilized myocytes showed increased sarcomere slack length and lower myofilament passive stiffness in adult Rbm24 HET compared to wildtype cardiomyocytes. As a result of the differences in sarcomere slack length, the relations between force development and sarcomere length differed between WT and Rbm24 HET hearts. No differences in sarcomere structure and titin isoform composition were observed. Likewise, in vivo cardiac function and myocardial structure was unaltered in Rbm24 HET mice compared to WT, at baseline and upon pressure overload after transverse aortic constriction. In conclusion, we generated a somatic Rbm24 KO model and recapitulated the previously reported embryonic phenotype. In adult Rbm24 HET cardiomyocytes we observed increased sarcomere slack length, but no difference in sarcomere structure and cardiac function.

MicroRNAs in heart failure: new targets in disease management.

Heart failure is the leading cause of mortality in Western society and represents the fastest growing subclass of cardiovascular diseases. An increasing body of evidence indicates an important role for microRNAs (miRNAs) in the pathogenesis and progression of heart failure. miRNAs are small noncoding RNAs that regulate expression of target genes by sequence-specific binding to the 3' untranslated region of messenger RNA, which results in degradation or translational repression. To date, many miRNAs (and their targets) that play a role in diverse aspects of cardiac remodeling and heart failure development have been identified. Here, we give an overview of these miRNAs and their role in cardiac pathogenesis. In addition, we provide brief insight into the potential of miRNAs as novel therapeutic targets for heart failure.

Exercise related ventricular arrhythmias are related to cardiac fibrosis in hypertrophic cardiomyopathy mutation carriers.

AIMS: Hypertrophic cardiomyopathy (HCM) is a frequent cause of sudden cardiac death (SCD) due to exercise-related ventricular arrhythmias (ERVA); however the pathological substrate is uncertain. The aim was to determine the prevalence of ERVA and their relation with fibrosis as determined by cardiac magnetic resonance imaging (CMR) in carriers of an HCM causing mutation. METHODS: We studied the prevalence and origin of ERVA and related these with fibrosis on CMR in a population of 31 HCM mutation carriers. RESULTS: ERVA occurred in seven patients (23%) who all showed evidence of fibrosis (100% ERVA(+) vs. 58% ERVA(-), p = 0.04). No ventricular tachycardia or ventricular fibrillation occurred. In patients with ERVA, the extent of fibrosis was significantly larger (8 ± 4% vs. 3 ± 4%, p = 0.02). ERVA originated from areas with a high extent of fibrosis or regions directly adjacent to these areas. CONCLUSIONS: ERVA in HCM mutation carriers arose from the area of fibrosis detected by CMR; ERVA seems closely related to cardiac fibrosis. Fibrosis as detected by CMR should be evaluated as an additional risk factor to further delineate risk of SCD in carriers of an HCM causing mutation.

Hereditary muscular dystrophies and the heart.

Cardiac disease is a common clinical manifestation of neuromuscular disorders, particularly of muscular dystrophies. Heart muscle cells as well as specialized conducting myocardial fibres may be affected by the dystrophic process. The incidence and nature of cardiac involvement vary with different types of muscular dystrophies. Some mainly lead to myocardial disease, resulting in cardiomyopathy and heart failure, while others particularly affect the conduction system, leading to arrhythmias and sudden death. As prognosis of muscular dystrophy patients may be directly related to cardiac status, surveillance and timely management of cardiac complications are important. However, recognition of cardiac involvement requires active investigation and remains challenging since typical signs and symptoms of cardiac dysfunction may not be present and progression is unpredictable. In this review, we present a comprehensive overview of hereditary muscular dystrophies associated with cardiac disease to provide an efficient strategy for the expertise and management of these diseases.

No effect of rosuvastatin on left ventricular hypertrophy in patients with hypertension: a prospective randomised open-label study with blinded endpoint assessment.

BACKGROUND: This study tested the hypothesis that statins may reduce left ventricular hypertrophy (LVH) in patients with hypertension and LVH. METHOD: A prospective randomised open-label study with blinded endpoints assessment was performed in 142 patients. Inclusion criteria were hypertension, left ventricular ejection fraction ≥50% and echocardiographic determined LVH, defined as a left ventricular mass index (LVMI) of ≥ 100 g/m(2) in women and ≥ 116 g/m(2) in males. Patients were randomised between rosuvastatin 20mg once daily vs control. For each patient an echocardiogram and blood samples were obtained. These tests were repeated after 6 months. RESULTS: Baseline characteristics: mean age was 62 ± 11year and 62 (44%) were male. In both groups, there was a non-significant reduction in LVMI: 118 ± 22 to 111 ± 19 g/m(2) in the control group and 118 ± 21 to 114 ± 22 in the rosuvastatin group (p=0.376 for the comparison between rosuvastatin and control after 6 months). After six months, LDL-cholesterol was reduced from 3.5 ± 1.0 to 2.1 ± 1.2 mmol/L (40% reduction) in the rosuvastatin group and remained unchanged in the control group (3.5 ± 0.9 vs 3.6 ± 0.9 mmol/L. Hs-CRP decreased more with rosuvastatin compared to control (-38% vs -15%, p=0.006) There was no significant reduction in NT-pro-BNP levels after 6 months. CONCLUSION: Rosuvastatin does not reduce LVH despite a large LDL reduction in patients with hypertension and LVH.

Hypertrophic cardiomyopathy family with double-heterozygous mutations; does disease severity suggest doubleheterozygosity?

Background. With the improvement in genetic testing over time, double-heterozygous mutations are more often found by coincidence in families with hypertrophic cardiomyopathy (HCM). Double heterozygosity can be a cause of the wellknown clinical diversity within HCM families.Methods and results. We describe a family in which members carry either a single mutation or are double heterozygous for mutations in myosin heavy chain gene (MYH7) and cysteine and glycine-rich protein 3 (CSRP3). The described family emphasises the idea of a more severe clinical phenotype with double-heterozygous mutations. It also highlights the importance of cardiological screening where NT-proBNP may serve as an added diagnostic tool.Conclusion. With a more severe inexplicable phenotype of HCM within a family, one should consider the possibility of double-heterozygous mutations. This implies that in such families, even when one disease-causing mutation is found, all the family members still have an implication for cardiological screening parallel to extended genetic screening. (Neth Heart J 2009;17:458-63.).

GENCOR: a national registry for patients and families suffering from a familial heart disease in the Netherlands.

INTRODUCTION: Developments in DNA-diagnostic techniques allow us to identify a significant proportion of patients with gene mutations causing familial heart diseass (arrhythmia syndromes, cardiomyopathies etc.) and to identify family members in early stages of the disease and/or even before symptoms occur. Early treatment can prevent sudden cardiac death and disease progression. However, data on long-term outcome in unselected genotyped patients are scarce due to a lack of large registries. In 2005, a national internet-based registry for familial heart diseases in the Netherlands, named GENCOR, was developed in collaboration with the Interuniversity Cardiology Institute of the Netherlands (ICIN). OBJECTIVES: GENCOR aims to assess the prevalence of familial heart diseases in patients and families in the Netherlands and to facilitate research to improve the quality of diagnostics and therapy in familial heart diseases. METHODS: Patients who visit the (cardio)genetic outpatient clinic are informed about GENCOR and asked to consent to the storage of information about cardiac examinations, family history and DNA diagnostics from all their visits. Patient data are entered into the internet-based GENCOR database by the cardiologist or clinical geneticist in attendance. Additional information can be stored for scientific research. RESULTS: Four university hospitals are actively obtaining informed consent from the patients, which resulted in the inclusion of more than 300 patients. In 2006, more university hospitals will start using GENCOR and the aim is that all university hospitals will participate. Three research projects have already started using GENCOR. CONCLUSION: GENCOR is already a success, regarding the number of included patients and the related research projects set up within a limited period of time. GENCOR provides easy internet-based access for authorised cardiologists, clinical geneticists and scientists throughout the country.

A-type lamins are essential for TGF-beta1 induced PP2A to dephosphorylate transcription factors.

Diseases caused by mutations in lamins A and C (laminopathies) suggest a crucial role for A-type lamins in different cellular processes. Laminopathies mostly affect tissues of mesenchymal origin. As transforming growth factor-beta1 (TGF-beta1) signalling impinges on the retinoblastoma protein (pRB) and SMADs, we tested the hypothesis that lamins modulate cellular responses to TGF-beta1 signalling, via the regulation of these transcription factors in mesenchymal cells. Here, we report that A-type lamins are essential for the inhibition of fibroblast proliferation by TGF-beta1. TGF-beta1 dephosphorylated pRB through PP2A, both of which, we show, are associated with lamin A/C. In addition, lamin A/C modulates the effect of TGF-beta1 on collagen production, a marker of mesenchymal differentiation. Our findings implicate lamin A/C in control of gene activity downstream of TGF-beta1, via nuclear phosphatases such as PP2A. This biological function provides a novel explanation for the observed mesenchymal dysfunction in laminopathies.

The value of (NT-pro) BNP in the diagnosis, prognosis and treatment of congestive heart failure.

Congestive heart failure constitutes one of the major causes of morbidity and mortality in Western countries. However, it is often misdiagnosed and the validity of the diagnosis is often difficult to establish. The clinical signs are not very sensitive and symptoms are nonspecific. Secretion of natriuretic peptides is increased in situations of cardiac overload. Testing the levels of these peptides, especially BNP and NT-proBNP, appears to offer a significant advance in the diagnosis and treatment of heart failure. In this article we would like to discuss the value of natriuretic peptides in congestive heart failure and give a short review of the literature.