Loss-of-function variants in founder population highlight atrial myopathy as susceptibility to atrial fibrillation

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and it's associated with genes responsible for cardiac conduction, cardiogenesis, and cardiac structure. The Finnish population has evolved in relative isolation and undergone several bottlenecks, resulting in enrichment of deleterious variants. This facilitates identification of possible causal genes through protein-truncating variants that likely would not have been identified in other populations.

Purpose

To identify novel genetic associations with large effect on AF risk.

Methods

We accessed publicly available summary statistics on AF (ICD-10 code I48) from the FinnGen project R6, containing 28,670 AF cases and 135,821 controls. Then, we annotated all variants in the summary statistics and extracted variants that were predicted with a high effect impact (n=7,113). To account for multiple testing, a false discovery rate cutoff <10% was applied. The UK Biobank was assessed for comparison of allele frequencies. Afterwards, we investigated protein and single-cell RNA expression of the genes of interest in human atrial tissue. Human atrial tissue was obtained by us from 7 individuals and used for mass spectrometry-based proteomics, while single-nucleus RNA sequencing (snRNAseq) data from human hearts was acquired by Tucker [1].

Results

In a genome-wide association study (GWAS) focusing on loss-of function (LOF) variation, we report two LOF variants in the structural genes SYNPO2L and CTNNA3 with much higher allele frequencies compared to non-Finnish Europeans (85-fold and 80-fold enrichment, respectively). The variants increase the risk of AF considerably, which is emphasized as the two variants show the highest effect sizes of all GWAS variants ever associated with AF (SYNPO2L; odds ratio [OR] = 2.79, P-value = 1.32x10–8 and CTNNA3; OR = 2.43, P-value = 9.40x10–7), exceeding that of most clinical risk factors. We accessed phenome-wide association study (PheWAS) results on both variants. There was no association with other phenotypes for the SYNPO2L variant whereas the CTNNA3 variant showed suggestive association with valvular heart disease (P-value = 2.95x10–5). SYNPO2L and CTNNA3 exhibited high protein and RNA expression levels in atrial tissue and were predominantly expressed in cardiomyocytes (Fig. 1).

Conclusion

We identified novel associations between LOF variation in the structural genes SYNPO2L and CTNNA3 and AF. Our study showed how genetic examination of a European subpopulation facilitates discovery of genetic variants and pathophysiological understanding. The results underline the importance of thoroughly investigating subpopulations as unique variants with large effect sizes can be identified.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): This work was supported by the Research Foundation at Rigshospitalet and the Hallas-Møller Emerging Investigator Novo Nordisk.

Maternal pre-existing diabetes and gestational diabetes and the prevalence of septal defects in the offspring

Background and introduction

Maternal pre-existing and gestational diabetes affect approximately 6% of all pregnancies in Denmark and are well known risk factors for congenital heart disease (CHD). Worldwide, CHD is the most common congenital defect and a leading cause of infant death. The association between maternal diabetes, and CHD in the offspring has previously been studied, however, these studies have been limited by small study cohorts and/or registry studies without systematic transthoracic echocardiography (TTE) of the children.

Purpose

To assess the prevalence of atrial and ventricular septal defects (ASD and VSD) in children born to mothers with pre-existing or gestational diabetes by systematic TTE, in a large, population-based cohort of neonates.

Method

Systematic, standardized TTE was performed in neonates included in a population-based cohort study between 2016 and 2018. For the present study, the prevalence of VSD in cases and controls was assessed in the entire cohort of neonates who underwent TTE within 30 days of birth, and in whom information regarding maternal diabetes was available (n=24,921). The prevalence of ASD was assessed in a sub-cohort of neonates (n=12,682) with the same inclusion criteria and in whom an interatrial communication had been classified as ASD or patent oval foramen according to a validated algorithm. ASD was defined as an interatrial communication with a defect size ≥4mm, a location in the inferior 1/3 of septum, or multiple communications. VSD was defined as flow across the interventricular septum in colour Doppler mode in one or more views. VSDs were classified as either muscular, perimembranous, or subarterial.

Information about maternal pre-existing and gestational diabetes was collected from review of the mother's medical records and from an Obstetrical Database maintained by the participating hospitals.

Cases were compared with controls, which here consists of the full cohort for VSD and sub-cohort for ASD, respectively, after excluding cases.

Results

The median age at examination of the entire cohort was 11 days [interquartile range (IQR) 7; 14] and 48% were female.

The prevalence of VSD in children with maternal diabetes was 3.1% compared with 3.3% among children of mothers without maternal diabetes, RR 1.00 (95% CI 0.99–1.01, p=0.771). There was no difference between cases and controls when comparing the prevalence of subtypes of VSD (table 1).

In the sub-cohort of 12,682 neonates assessed for ASD (median age at examination 12 days [IQR, 8; 15], 48% female), the presence of an ASD was found in 7.3% of cases compared to 5.9% among controls, RR 0.81 (95% CI 0.59–1.13, p=0.214).

Conclusion

In a large population-based cohort of infants, we did not find an increased risk for ASD or VSD, nor any of the subtypes of VSD, among children born to mothers with pre-existing or gestational diabetes as compared to controls.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): The Capital Region of Denmarks Research Fund.The Research Council of Herlev and Gentofte Hospital.

PMHnet-alpha: development and validation of a neural network based discrete-time survival model for mortality prediction in ischemic heart disease

Background

Current risk prediction models in ischemic heart disease (IHD) use a small set of well-known risk factors, have limited predictive capabilities, and are largely the same as they were twenty years ago.

We developed and externally validated PMHnet-alpha, a neural-network based survival model for risk-stratification in ischemic heart disease that leverages the multitude of clinical features available in modern electronical health records.

Methods

We included 39,746 IHD patients from the regional Heart Registry that had been subjected to a coronary angiography between 2006 and 2017 with confirmed coronary artery disease.

Clinical data was extracted from the Danish National Patient Registry, and electronic health records.

595 different features, consisting of diagnosis codes, procedure codes, biochemical test results, and clinical measurements were used as model inputs.

Prior to model development, patients were randomly divided into a training set (n=34,746) and a tesing set (n=5,000).

The testing set was not used for model development.

Model performance was evaluated at six months, one years, three-, and five years of follow-up using time-dependent ROC curve analysis and Harrels' C-index.

Lastly, we also assessed the calibration of the model.

We benchmarked the performance of PMHnet-alpha against the GRACE Risk Score 2.0, which is widely considered to the best-performing model in current clinical use.

We explored the importance of individual features using SHAP values on the trained models.

Findings

PMHnet-alpha had very high model discrimination on the testing data with time-dependent AUCs of 0.88 (95% CI 0.86–0.90) at six months, 0.88 (95% CI 0.86–0.90) at one year, 0.84 (95% CI 0.82–0.86) at three years, and 0.82 (95% CI 0.80–0.84) at five years.

The discrimination of the benchmark model GRACE2.0 on the same data was considerably lower, 0.77 (95% CI 0.73–0.80) at six months, 0.77 (95% CI 0.74–0.80) at one year, and 0.73 (95% CI 0.70–0.75) at three years.

PMHnet-alpha is undergoing external validation in other nordic countries.

We identified that on-average, age, coronary pathology and smoking status were the most impactful features.

Interpretation

Here we present a significant improvement of the state of the art in cardiac risk prediction.

PMHnet-alpha supports better and optimized use of available healthcare data, signified by the vast improvement compared to GRACE2.0.

This also signifies an important paradigm shift in which data-driven strategies are necessary to transform the increasing amount of data generated in the modern healthcare system into evidence-based clinical decision making.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The Novo Nordisk Foundation, NordForsk

Prevalence of Wolff-Parkinson-White syndrome, association with congenital heart disease, and natural history in newborns

Background

Wolff-Parkinson-White (WPW) syndrome is characterized by an accessory electrical pathway between the atria and ventricles. Clinically, the condition can lead to supraventricular tachycardia, and is associated with sudden cardiac death and congenital heart disease. Studies investigating the prevalence, associated structural cardiac abnormalities, and natural history in newborns are few.

Purpose

To determine the prevalence of WPW syndrome in newborns, describe electrocardiographic and echocardiographic characteristics, and the natural history in childhood.

Methods

Electrocardiograms (ECGs) and echocardiograms of newborns (aged 0–30 days) from a large, prospective, general population study were included. WPW cases were identified through manual evaluation of outliers in PR-interval, QRS-duration, and QRS axis. Newborns with suspected or confirmed pre-excitation on their initial ECG were offered a cardiac follow-up. Localization of the accessory pathway was assessed utilizing a QRS polarity algorithm. Cases were matched 1:4 to controls by age, sex, weight and gestational age.

Results

Among the 17,489 ECGs we identified 17 (76% boys) newborns with definite WPW syndrome consistent with a prevalence of 0.1%. At follow-up (available in 12/17 children) at a mean age of three years, the WPW pattern remained in three children while the ECG had normalized in the nine remaining children. The median values for the newborns' heart rate, PR-interval, QRS-duration, QTc(Bazett), the maximum amplitude in R-V1 and S-V6 in cases and controls were 131 vs. 142 beats per minute, 80 vs. 96 ms, 74 vs. 56 ms, 449 vs. 420 ms, 1,562 vs. 1,028 μV and 546 vs. 693 μV, respectively (all p<0.05, Figure 1). The newborns' QRS axis, max amplitude in S-V1 and R-V6 did not differ among cases and controls (all p>0.05). Echocardiographic measurements of the newborns' left ventricular diameter and function, wall thicknesses, and doppler measurements of trans-mitral- and main pulmonary artery blood flow did not differ significantly between cases and controls (all p>0.05). The accessory electrical pathway was left-sided in 14 (82%) of the newborns. One newborn had significant mitral regurgitation while all other newborns had structurally normal hearts; there were no cases of Ebstein's anomaly.

Conclusion

The prevalence of WPW syndrome in our cohort of asymptomatic newborns was 0.1%. The syndrome was more frequent in boys, the accessory pathway was mostly left-sided, and was associated with changes in several ECG parameters, but generally not associated with structural heart disease. A striking observation was, that the WPW pattern in the majority of children could not be reproduced on follow-up ECGs at a mean age of three years, suggesting either that the ECG pattern is intermittent, or normalization occurs.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The Danish Heart Foundation

Left ventricular non-compaction in childhood: echocardiographic follow-up and prevalence in first-degree relatives

Introduction

Left ventricular non-compaction (LVNC) is characterized by excessive trabeculations of the left ventricular wall. LVNC may be associated with reduced systolic function but is also found in individuals with normal ventricular function. It is debated whether LVNC is only congenital or may develop later in life. The clinical importance and heredity of LVNC with normal systolic function is unclear.

Purpose

We aimed to describe the echocardiographic development of the left ventricular function and LVNC pattern in children with LVNC, diagnosed at birth, at follow-up at the age of 2–4 years compared to matched controls. Additionally, we aimed to describe the prevalence of LVNC in first-degree relatives.

Methods

A follow-up transthoracic echocardiography was performed in children at 2–4 years of age, diagnosed with LVNC at birth (<30 days) as part of a large population study of newborns (n>25,000). Cases were matched 1:4 to controls on mother's age at delivery, parity, and age of the child at follow-up. First-degree relatives (parents, siblings and half-siblings) of cases and controls were also offered inclusion. LVNC was defined as a ratio of non-compact to compact myocardium of ≥2 in at least one left ventricular segment measured in end-diastole perpendicular to the left ventricular cavity.

Results

13 of the 16 children diagnosed with LVNC at birth (median age 3 (interquartile range (IQR) 3–4) years, 77% male) and 52 children without LVNC at birth (age 4 (IQR 3–4) years, 88% male) was reevaluated as well as 36 first-degree relatives of children with LVNC (age 30 (IQR 4–37) years, 44% male) and 136 first-degree relatives of children without LVNC (age 32 (IQR 10–38) years, 50% male). In probands, the number of segments fulfilling criteria (8% vs. 13%, p=0.4) and systolic function, measured as fractional shortening (FS), were unchanged from birth to follow-up, and within normal range (29% vs. 30%, p=0.34). However, at follow-up, FS was significantly lower in probands compared with matched controls (30% vs. 33%, p<0.001). Criteria of LVNC was fulfilled in 11 out of 36 (31%) first-degree relatives to probands, whereas none of the first-degree relatives of children without LVNC fulfilled criteria of LVNC (p<0.001). FS was significantly lower in first-degree relatives of probands fulfilling criteria of LVNC compared to first-degree relatives of matched controls (30% vs. 32%, p=0.01).

Conclusion

Children with LVNC diagnosed neonatally as part of a population study still had a reduced systolic function when compared to controls but showed no further progression of left ventricular dysfunction or extent of trabeculation at the age of 2–4 years. One third of first-degree relatives to children diagnosed with LVNC with a preserved systolic function, fulfilled criteria for LVNC and had reduced systolic function compared to controls. These findings strongly support family-screening and clinical follow-up of children with LVNC.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Novo Nordisk FoundationHerlev-Gentofte Hospital Internal Funding

Characteristics and outcomes in patients with infective endocarditis caused by Enterococcus faecium and Enterococcus faecalis

Background

Enterococcus faecalis is the third most common cause of infective endocarditis (IE) and has been associated with a higher risk of relapse and death. Within the enterococcus species, E. faecium is the second most frequent cause of IE. As IE from E. faecalis or E. faecium most likely have different presentations and outcomes, research is needed for individualised and optimised clinical management.

Purpose

This study aims to characterise baseline characteristics and clinical outcomes for patients with IE caused by E. faecalis or E. faecium, including short- and long-term mortality and relapse. Additionally, we aim to determine risk factors associated with IE caused by the two bacterial species.

Methods

This is a retrospective study of patients hospitalised with at least one positive blood culture with E. faecalis or E. faecium between January 1, 2016 and December 31, 2018 at two large hospitals in Denmark. IE was diagnosed according to the modified Duke criteria. Index and follow-up data were collected from medical records. Categorical values were compared using chi-square test and categorial data using students t-test.

Results

614 patients had a positive blood culture with either E. faecalis (n=279) or E. faecium (n=335). Of these, 64 (10.4%) patients developed IE; E. faecalis in 56 patients (87.5%, male 83.3%, mean age 70 years (SD 14)) and E. faecium in 8 patients (12.5%, male 75.0%, mean age 65 years (SD 13)). The prevalence of IE was 20.1% for E. faecalis bacteraemia and 2.4% for E. faecium bacteraemia (p<0.001). Embolic events during primary admission were seen more often in the E. faecium group (62.5%) compared to the E. faecalis group (10.7%) (p=0.002). Both groups had multiple co-morbidities without significant differences between groups (Table 1).

Nineteen (40.4%) of the patients with E. faecalis IE had a minimum of one previous admission with E. faecalis bacteraemia within the last year before the IE diagnosis, whereas this was not seen for any patients with E. faecium IE. The 30-days all-cause mortality was 5.4% for patients with E. faecalis IE and 25% for patients with E. faecium IE (p=0.22). After a median follow up of 3.1 years (IQR=0.46–3.94) all-cause mortality was 55.4% for patients with E. faecalis IE and 62.5% for patients with E. faecium IE (p=1.00) (Table 1).

Conclusion

The prevalence of IE was significantly higher in patients with E. faecalis bacteraemia than with E. faecium bacteraemia. While the prevalence of complications was higher in patients with E. faecium IE, the difference was only significant for embolic events. This indicates that E. faecium IE is associated with a worse outcome compared to the outcome in patients with E. faecalis IE. All-cause mortality was above 50% for both groups, i.e. considerably higher than generally seen in patients with IE. These findings may be of importance of management of patients with E. faecalis or with E. faecium bacteraemia – and endocarditis.

Funding Acknowledgement

Type of funding sources: None.

Genome-wide association study on cerebral white-matter hyperintensities in 36,577 individuals

Background/Introduction

A quarter of all strokes are caused by cerebral small vessel disease (CSVD), which is also the most common pathology underlying vascular dementia. [1] White matter hyperintensities (WMH), a radiological marker detectable on magnetic resonance imaging (MRI), can serve as a proxy for CSVD. WMH is associated with stroke, increased risk of dementia and functional decline in older age. [2,3]

Purpose

We aimed at investigating the genetic architecture of WMH using cerebral MRI data.

Methods

We used imaging data ∼40,000 individuals from the UK Biobank, a large population-based, prospective cohort study. We selected individuals with available total volume of WMH from T1 and T2_FLAIR images.

We performed a genome-wide association study (GWAS) on autosomal genetic variants assuming an additive model based on genotype dosages with BOLT-LMM treating WMH as outcome.

We applied LD score regression (LDSC software) to estimate the genetic correlation between WMH traits and traits selected based on availability and relevance for cardiovascular disease.

Results

We included a total of 36,577 individuals with available quality controlled cerebral MRI data.

Genome-wide analysis identified 20 loci of statistical significance, six of which are not previously reported (Fig. 1). Within these novel loci, the following genes are located in proximity to lead variants: EHBP1, OTX1, WDPCP, VCAN, WNT16, FAM3C, ERI1, PRAG1, CACNB2, MTHFSD, FOXL1, FOXC2. Using BOLT, we found the heritability of WMH to be 37%.

We investigated genetic correlation between WMH and multiple phenotypes (Fig. 2). We observed the highest correlation with small vessel stroke (rg=0.56, P=3.9x10–4) Interestingly, WMH was genetically correlated with left atrial volume (rg=0.24, P=2.8x10–3).

Conclusion

In a GWAS on WMH acquired from cerebral MRI, we identified 20 significant loci, of which six are novel. This genetic study provides insights on the biological understanding and epidemiology of CSVD.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): John and Birthe Meyer FoundationThe Hallas-Møller Emerging Investigator Novo Nordisk

First-in-man trial of b3-adrenoreceptor agonist treatment in chronic heart failure – impact on diastolic function

Background

Diastolic dysfunction (DD) in heart failure (HF) is associated with increased myocardial cytosolic calcium, and calcium-efflux via the sodium-calcium-exchanger depends on the sodium gradient. Beta-3-adrenoceptor (β3-AR)-agonist lowers cytosolic sodium and has been shown to reverse organ congestion.

Purpose

To assess whether β3-AR-agonist treatment improves DD.

Methods

In a first-in-man randomized controlled, double-blind trial, we assigned 70 patients with HF with reduced ejection fraction (HFrEF) (NYHA II–III) and LVEF <40% to receive mirabegron (300 mg/day) or placebo for 6 months, in addition to recommended HF-therapy. Patients were assessed with echocardiography and cardiac computed tomography (CCT) at baseline and follow-up. DD was graded according to the current American/European guidelines.

Results

Baseline and follow-up echocardiographic data were available in 57 patients (59±11 years, 88% male, 49% ischemic heart disease). Baseline LVEF was 34%±8%. No significant change in DD grade was found between the groups at follow-up, p=0.72. Neither was there any clinical differences in any singular diastolic parameters within or between groups by echocardiography (E/e' placebo: 13.3±6.9 to 12.6±5.1, p=0.19 vs. mirabegron: 12.0±5.7 to 12.8±7.9, p=0.67, mean difference 1.12 [95% CI −1.68 to 4.3], p=0.37), or CCT (left atrial max volume index: between group mean difference 0.2 [95% CI −6.2 to 5.6] ml/m2, p=0.91).

Conclusions

In patients with HFrEF, no improvement nor worsening in DD gradings or singular diastolic parameters after β3-AR stimulation compared to placebo were identified. The findings add to previous literature questioning the role of impaired Na+-Ca2+ mediated Ca2+ export as a major culprit in DD.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The Heart Centre Research Foundation, RigshospitaletThe Novo Nordic Foundation

Family screening in dilated cardiomyopathy-qualifying screening and need for follow-up

Background

Guidelines recommend family screening in dilated cardiomyopathy to uncover pre-symptomatic disease to improve morbidity and mortality through early treatment. According to patterns of inheritance and incomplete penetrance, less than half of relatives to dilated cardiomyopathy probands will develop disease, but so far, no guidelines provide recommendations on the frequency and intensity of follow-up screening.

Purpose

To investigate the prevalence and incidence and identify predictors of developing familial dilated cardiomyopathy (FDC) in relatives participating in family screening.

Methods

The study was an observational, longitudinal cohort study of families screened and followed from 2006 to 2020, at a regional assembly of clinics for inherited cardiomyopathies in Denmark.

Results

We included 211 families totaling 774 subjects (n=563 relatives, 47% women). At baseline, 124 relatives (22%) were diagnosed with dilated cardiomyopathy, while 43 relatives (8%) not fulfilling FDC criteria were found to carry class IV to V genetic variants. Thus, the combined clinical and genetic yield of screening was 30% at baseline. Relatives not fulfilling diagnostic criteria for FDC at baseline (n=439), were stratified into four groups based on results from genetic screening and clinical work-up at baseline (Figure 1). The risk of developing FDC during follow-up was strongly associated with this classification (see figure 1 and 2). The highest risk of developing FDC was observed in relatives carrying class IV to V genetic variants (n=43, age-adjusted incidence rate of 10% per person-year), while none of the subjects identified as non-carriers of family variants developed disease (n=58). In subjects sub-grouped according to baseline-findings on ECG and echocardiography, relatives with abnormal (n=70) vs normal (n=268) findings had markedly higher incidence rates of FDC (overall 4.7% vs 0.4% per person-year), regardless of age-group (Figures 1 and 2). The relatives with abnormal ECG and/or echocardiographic findings at baseline had a (age-group-adjusted) hazard ratio of 12.9 (CI: 4.8 to 35.1, p<0.001), when compared to relatives with normal findings.

Conclusion

Family screening identified a genetic predisposition to or overt FDC in 30% of screened relatives at baseline. In relatives not fulfilling criteria for FDC at baseline, findings from genetic testing and/or non-diagnostic findings on echocardiography and/or ECG were strongly associated with progression to disease. Importantly, relatives with normal genetic or objective findings had a low incidence rate and overall risk of developing FDC. Thus, baseline-screening identified a large proportion of relatives, in whom follow-up can be considered to be reduced allowing focused follow-up of relatives at higher risk of progression.

Funding Acknowledgement

Type of funding sources: None.

Yield of echocardiographic screening of first-degree relatives of children with bicuspid aortic valve

Background

Bicuspid aortic valve (BAV) is the most common congenital heart defect, affecting 0.8% of new-borns. BAV is associated with valve dysfunction, as well as an increased risk of aortopathy. The prevalence of BAV in first-degree relatives of symptomatic BAV patients, is reported to be 5–10%. First-degree relatives also have an increased risk of aortic dilatation, independently of aortic valve morphology.

Purpose

The purpose of the study was to determine the prevalence of BAV, associated valve dysfunction and aortopathy in first-degree relatives to children diagnosed with BAV neonatally in a population-based study.

Methods

Between April 2016 and October 2018 all expecting parents at three major maternity centres were offered inclusion in a large-scale population study with focus on congenital heart disease (N≥25,000). A total of 197 children, in 196 families, were diagnosed with BAV. All first-degree relatives, including half-siblings, were offered inclusion in the follow-up study with standardized transthoracic echocardiography. Adults were also examined with transoesophageal echocardiography. Aorta diameters were measured at the AV annulus, sinuses of Valsalva, sino-tubolare junction and in the proximal ascending aorta. Aortic dilatation in children were defined as any aortic root or ascending aorta diameter ≥2 standard deviations (SD) from the expected mean, calculated as z-score using formulas from the Paediatric Heart Network Echocardiogram Database. In adults, aortic dilatation was defined as aortic root and/or ascending aorta diameters indexed to body surface area (BSA) exceeding normal reference values established by the European Association of Cardiovascular Imaging.

Results

In total, 352 first-degree relatives (242 adults [35.3 years SD 5.5] and 110 children [4.5 years, SD 3.5] were included. BAV was diagnosed in 24 relatives (6.8%). BAV could not be conclusively ruled out in 52 relatives (14.8%), who are awaiting further examination with transoesophageal echocardiography. Dilatation of the aortic root was observed in 8 adult relatives and in 17 children (7.1%). Aortic valve regurgitation was observed in 23 relatives (6.5%). In total 58 relatives (16.2%) were diagnosed with either BAV, dilated aorta, or aortic regurgitation.

Conclusion

One in fifteen first-degree relatives to children diagnosed with BAV neonatally, also had BAV, corresponding to >8 fold increase in prevalence compared with the background population. One in six relatives had BAV, dilated aorta, or aortic regurgitation. These findings are of importance for family-screening programs of BAV.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Danish Children's Heart Association

High prevalence of deleterious variants in cardiomyopathy genes in patients with early onset atrial fibrillation

Background

Atrial Fibrillation (AF) is a common cardiac arrhythmia associated with increased morbidity and mortality. AF has a significant heritable component and genome-wide association studies have associated numerous loci in the human genome with AF. The arrhythmia is relatively rare in younger individuals, but studies have shown that individuals with early-onset AF may harbour a considerable burden of pathogenic genetic variants.

In recent years, the concept of atrial cardiomyopathy has emerged as a mechanism involved in AF pathogenesis. Genes well-known to be related to ventricular structure, including cardiomyopathies have now also been associated with AF.

Purpose

Using targeted genetic sequencing, this study aimed to elucidate the role of deleterious genetic variants in cardiomyopathy genes in early-onset AF, and provide new insights into AF pathogenesis.

Methods

We performed targeted genetic sequencing of 445 Danish individuals with onset of AF before age 40 years and no other cardiovascular co-morbidities, and of 387 controls with no history of AF. Based on guidelines for genetic testing for clinical use, we focused on 30 genes with well-established associations with dilated cardiomyopathy, hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. We examined the prevalence of loss-of-function variants (defined as variants leading to premature stop-codon, frameshift or splice-site variants), as these are most likely to be disease-causing. We filtered for rare variants using a minor allele frequency <0.1%. The difference in prevalence in the two groups was analyzed using a logistic regression model.

Results

We found that 38 of the 445 early-onset AF patients carried loss-of-function variants in well-established cardiomyopathy genes. The prevalence of rare, loss-of-function variants was enriched in cases compared with controls (8.5%. vs. 1.0%, P=8.27x10–7). The variants were identified in eight different genes, with most rare variants found in the TTN gene (Table 1). In sensitivity analyses excluding TTN variants, we found that 12 individuals (∼2.7%) with AF harbored deleterious loss-of-function variants (P=0.0396).

Conclusions

Individuals with early onset of AF have a considerable burden of rare, deleterious variants in established cardiomyopathy genes. These new insights could help inform future recommendations for genetic testing and follow-up to detect early cardiomyopathy manifestations to prevent adverse outcomes in patients with early onset of AF. These findings support the presence of atrial cardiomyopathy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Hallas-Møller emerging investigator grant, The Novo Nordisk Foundation (NNF: NNF17OC0031204)The John and Birthe Meyer Foundation

Genome-wide multi-trait analysis on cardioembolic stroke identifies 47 novel loci

Background

Ischemic stroke is one of the leading causes of death and disability-adjusted life-years worldwide. It has several subtypes and cardioembolic stroke (CES) accounts for 15–30% of ischemic strokes. Atrial fibrillation (AF) is the most important risk factor for CES. AF increases the risk of stroke up to 5-fold and there is a substantial overlap in the aetiology of AF and CES. Large genome-wide association studies (GWAS) on AF have identified more than 150 common and rare genetic variants. However, the difficulty in acquiring large sample sizes of CES cohorts has hindered the genetic description of the disease.

Purpose

In this study, we mapped the genetics of CES to increase our understanding of the molecular biology driving the disease. By leveraging the large genetic cohorts of AF through a multi-trait analysis of AF and CES, we aimed to bypass the lack of statistical power for studying the genetics of CES.

Methods

First, we obtained the largest possible sample size of AF GWAS by conducting a meta-analysis on publicly available summary statistics from the FinnGen study (v5) and the largest multi-ethnic meta-analysis on AF to date. Summary statistics for stroke were obtained from the largest multi-ancestry GWAS on stroke to date, MEGASTROKE, which examined different ancestries and stroke subtypes. Multi-trait analysis requires a high genetic correlation. Genetic correlations between the different stroke summary statistics and the AF meta-analysis were assessed with LD Score Regression.

Second, we performed a joint meta-analysis of CES with MTAG using the CES summary statistics from MEGASTROKE and the AF GWAS meta-analysis. MTAG recalculates p-values and effect sizes for each trait separately by leveraging the covariation for correlated traits. The MTAG-computed summary statistics for CES and AF were subjected to genomic loci characterisation, with functional and annotation analysis carried out by FUMA.

Results

We show a high genetic correlation between CES and AF (rg = 0.88). Using MTAG, the GWAS meta-analysis of CES increased the effective sample size by almost 3 folds (n=24,639, Table 1). We discovered 50 CES loci whereof 47 are novel (Fig. 1). We mapped 101 genes to CES MTAG computed summary statistics, obtaining enrichment in gene sets involved in cardiac conduction and contraction, cardiac tissue development and cranial skeleton morphogenesis.

Conclusion

In conclusion, we identified 47 novel CES loci and demonstrated a substantial shared genetic variation with AF. We furthermore mapped 98 genes not previously linked to CES by AF. These results represent findings that potentially could be used for antithrombotic drug discovery and are a major advance in our understanding of the genetic underpinnings of CES

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): John and Birthe Meyer Foundation, the Research Foundation of the Heart Centre, Rigshospitalet, the Research Council at Rigshospitalet.The Hallas-Møller Emerging Investigator Novo Nordisk (NNF17OC0031204), Arvid Nilsson Foundation

Arrhythmogenic right ventricular cardiomyopathy – evolution of electrocardiographic markers during long-term follow-up prior to ascertainment of diagnosis

Background

Depolarization and repolarization abnormalities are part of the diagnostic Task Force Criteria of 2010 (TFC2010) for arrhythmogenic right ventricular cardiomyopathy (ARVC). These abnormalities are thought to be progressive but have also been described as dynamic and sometimes reversible. Evolution of ECG abnormalities prior to clinical ARVC diagnosis is poorly studied.

Objective

To assess the evolution of ECG depolarization and repolarization characteristics in patients with ARVC prior to diagnosis and to identify markers of disease progression at a preclinical stage.

Methods

353 patients with definite ARVC from Sweden, Denmark, the Netherlands and Canada with at least one 12-lead digital ECG (65% males, 67% probands, 56% mutation carriers, median age at diagnosis 42 [IQR 29–53] years and median age at first ECG 44 [30–55] years) were included. Digital ECGs were extracted from regional ECG archives. ECGs with left bundle branch block, ventricular pacing or recorded either prior to 15 years of age or after heart transplantation were excluded. Remaining 6,871 ECGs were digitally processed and automatically analysed using the Glasgow algorithm. Median values for overall QRS duration, terminal activation delay (TAD) in lead V1 as well as amplitudes of QRS-T-components in precordial leads per patient per year were used for analyses and graphically represented using Lowess smoothing with cubic splines (Figure 1). Blue lines indicate smoothed conditional mean with 95% confidence interval (shadow). Time “0” (red line) indicates the time when TFC2010 were fulfilled for definite diagnosis.

A database of 18,564 anonymized digital ECGs (58% males, median age at latest ECG 41 years [IQR 32–52]) who were in contact with health care during 2020–2021 was processed using the same exclusion criteria and signal-processing methodology as in the ARVC group and used as a reference (black line).

Results

TAD in lead V1 and overall QRS duration demonstrated a significant increase years before ARVC diagnosis, and significant reductions were seen in QRS-T voltages measured as R wave amplitude, QRS amplitude (the absolute sum of R wave and S wave), and T wave amplitude (Table 1 and Figure 1). The changes were seen in all precordial leads, not only the right-sided, and visually diverging from the controls.

Conclusion

Development of the ARVC ECG phenotype started several years before diagnosis and continued afterwards. QRS duration and TAD increased, QRS voltages decrease, and T wave amplitude decreased eventually leading to T wave inversion. These changes might be visually assessed but also measured with available ECG software. These findings may be clinically useful in the screening and follow-up of ARVC relatives.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Governmental funding of clinical research (ALF), Region Ostergotland, Sweden.The Swedish Heart-Lung Foundation.

The impact of perinatal factors on the neonatal electrocardiogram

Background

Myocardial development is still incomplete by the time of birth making the cardiomyocyte vulnerable in the perinatal period. However, little is known on whether perinatal factors affect the neonatal electrocardiogram, and if so, to what degree these effects persist in the neonatal period.

Purpose

To investigate the impact of maternal and perinatal factors on the neonatal electrocardiogram in a large unselected cohort of neonates.

Methods

In a multicentre, prospective, population-based cohort study, neonates underwent cardiac evaluation during the first month of life. Electrocardiograms and echocardiograms were obtained and systematically analysed. Medical and demographic information on the parents, pregnancy, and birth-related factors were registered, and the following perinatal risk factors were evaluated: maternal comorbidities, maternal BMI ≥25, use of assisted reproduction technology, parity, (preterm) premature rupture of membranes, placental disorders, abnormal foetus presentation, induction of labour with synthetic hormone, instrumental induction, administration of nitrous oxide, epidural/spinal administration, labour ≥24h, pushing stage ≥1h, Caesarean section, and instrumental delivery.

Results

A total of 15,928 singletons with normal echocardiograms were included (52% boys; median age at examination 11 days). The neonates were divided into groups by accumulated number of perinatal risk factors: 0 (n=1,587), 1 (n=3,718), 2 (n=4,026), 3–4 (n=4,998), and ≥5 (n=1,197), and differences in ECG parameters between the groups were analysed. Heart rate, QRS axis, uncorrected QT interval, QTcBazett, QTcFridericia, and maximum amplitudes in R-V1 and R-V6 differed across the five subgroups (all p<0.05). We observed a cumulative effect of perinatal risk factors on ECG parameters with increasing left-shift in the QRS axis, prolongation of the QT interval, and increasing amplitudes in R-V1 and R-V6. The subgroup with ≥5 perinatal risk factors differed the most, and absolute differences between this subgroup and neonates without any perinatal risk factors were 7.6% in maximum amplitudes in R-V6 (940 vs. 874 μV, p<0.01), 4.3% in R-V1 (1,201 vs. 1,152 μV, p<0.05), 5.1% in the QRS axis (111 vs 117°, p<0.0001) and 0.8% in QTcFridericia (366 vs. 363 ms, p<0.01).

Conclusion

We observed a cumulative effect of perinatal risk factors including a significantly more left-shifted QRS axis, increased values of the QT interval, and higher amplitudes in R-V1 and R-V6 in the subgroup with ≥5 perinatal risk factors. These findings suggest a relatively lower right ventricular dominance pattern, discrete prolongation of the QT interval and increased myocardial mass of the right ventricle in neonates exposed to multiple perinatal risk factors. However, the absolute differences in ECG parameters were relatively small. These findings may be useful for identification of neonates with increased cardiovascular risk.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Department of Cardiology, Herlev-Gentofte Hospital, Internal Funding

Prevalence and subtypes of interatrial communications in 12,718 newborns

Introduction

Patency of the oval foramen (PFO) and atrial septal defects (ASDs), i.e. interatrial communications, have been reported to be present in 24–92% of newborns. For isolated ASDs, the reported prevalence varies from 0.3–2.4 per 1000 livebirths. This broad range partly reflects the absence of a clear and universal clinical classification of interatrial communications. On this basis we have recently proposed a clinically applicable echocardiographic algorithm for classification of interatrial communications (figure 1), which proved superior to standard assessment by experts in terms of inter- and intraobserver agreement.

Purpose

To determine the prevalence of interatrial communications in newborns.

Methods

Echocardiograms (TTEs) from newborns (0–30 days) included in a population study (N>25,000) were assessed/analyzed for interatrial communications according to the new algorithm and categorized into three PFO subtypes and three ASD subtypes.

Results

TTEs from 16,420 newborns were analyzed; 3,694 (22.5%) were excluded due to suboptimal image quality and 9 (<0.1%) were excluded due to concurrent severe congenital heart disease. Of the remaining 12,718 included newborns (median age 12 days [8; 15], 48.1% female), an interatrial communication was present in 10,033 (78.9%) cases; 9,274 (72.9%) cases were classified as PFO while 759 (6.0%) were classified as ASD. In the ASD group, 368 (48.5%) had a defect size ≥4 mm, 364 (48.0%) had multiple interatrial communications, and 27 (3.6%) had the defect located in the lower 1/3 part of the septum (figure 2).

Conclusion

An interatrial communication was present in almost 4 out of 5 newborns. ASD was diagnosed in 6% of the newborns and the prevalence of PFO was 12 times higher than the prevalence of ASD. Follow-up studies of these children are expected to provide clinically useful information on the long term structural and hemodynamic impact of these well categorized ASD and PFO subtypes.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Candy's Foundation, The Danish Children's Heart Foundation

Long-term impact of persistent vegetations at 6 month followup after treatment of infective endocarditis: a substudy of the Partial Oral vs Intravenous Antibiotic Treatment of Endocarditis (POET) tria

Background

Our knowledge of changes in vegetation size throughout the course of infective endocarditis (IE) and the impact of persistent vegetations on mortality or embolization after completed antibiotic treatment is sparse. No study has previously investigated the prevalence or clinical impact of persistent vegetations on transthoracic echocardiography (TTE) at 6-months follow-up after ended IE treatment.

Purpose

To investigate the association between persistent vegetations at the 6-months TTE after treatment for IE and long-term prognosis as assessed in the POET trial.

Methods

The POET trial was a nationwide, multicenter RCT, randomizing 400 patients to either partial oral or intravenous (IV) antibiotic treatment of left-sided IE, after initial stabilization of infection using conventional IV therapy.

A persistent vegetation was defined as a vegetation seen on 6-months follow-up TTE (4–7 months) after ended antibiotic treatment for IE. In the POET trial, primary outcome was defined as 1) all-cause mortality, 2) unplanned cardiac surgery, 3) embolic events or 4) relapse of bacteremia, in the 5-year follow-up period. Patients without TTE due to death or lack of available TTE were excluded.

Results

Out of 400 patients, 20 were excluded due to death during 6-months follow-up, and 201 were excluded due to unavailable TTE, leaving 179 TTEs for analysis.

At 6-months follow-up, a persistent vegetation was seen in 30 patients (16.7%, 21 males (70%), mean age 69.6 years (SD 7.7)) (Table 1). Seventeen patients (56.7%) had a persistent vegetation on the aortic valve and 13 patients (43.3%) on the mitral valve. More patients without a persistent vegetation had undergone initial surgical treatment of IE than those with a vegetation (57.7 vs 23.3%, p=0.001). In all surgically treated patients with persistent vegetation at 6-months follow-up, the vegetation was found on another valve than the operated valve.

The composite primary outcome from 6-months follow-up and until 5-year follow-up occurred in 8 patients (26.7%) with a persistent vegetation, compared to 38 patients (25.5%) (p=1.00) without. (Table 2) In patients randomized for peroral treatment, no significant difference in prevalence of persistent vegetation was found (15 patients (50%) with persistent vegetations vs. 74 patients (49.7%) without, p=1.00).

Conclusion

The occurrence of persistent vegetations at 6 months follow-up was 16.7%. There was no association between persistent vegetations at 6-months follow-up and the occurrence of the primary outcome after 5 years follow-up, suggesting that the risk associated with residual vegetations after end of antibiotic treatment is negligible after 6-months.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The Danish Heart Foundation

Temporal trends in the incidence of endocarditis among patients with a prosthetic heart valve: a nationwide study

Background

The incidence of infective endocarditis (IE) is increasing in the adult population, as is the insertion of prosthetic heart valves. Patients with prosthetic heart valves are considered at high risk of IE – a complication with a high mortality. However, data on temporal changes in the incidence of IE among patients with prosthetic heart valves from unselected cohorts are sparse

Purpose

We aimed to examine nationwide temporal trends in the incidence of IE in patients with an implanted prosthetic heart valve in Denmark from 1999 to 2018.

Methods

Using Danish nationwide health-care registries we identified all patients, who underwent heart valve implantation between 1996–2018. Crude annual incidence rates per 1,000 person years (PY) of IE were computed and presented in two year intervals. Analyses were stratified by sex and age groups (<50, 50–59, 60–69, 70–79, >80 years).

Results

We identified 26,604 patients with first time prosthetic valve implantation with a median age of 72.7 years at the time of implantation, 63.1% were men with a median follow-up of 6.5 years. We found 1,442 cases of first time IE. The IE incidence rate ranged from 5.4 /1,000 PY (95% CI 3.9–7.4) in calendar period 2001–2002 to 10.0/1,000 PY (95% 8.84–11.11) in calendar period 2017–2018 with an unadjusted increasing trend during the study period (ptrend<0.0001), (Figure 1). Overall, men had a higher crude incidence rate compared with women, however no significant temporal changes were seen in the incidence rate during the study period. For age groups, a trend of stepwise increase in the incidence rate of IE was observed for increasing age groups, however no temporal changes were observed (Figure 2).

Conclusion

The incidence of IE following prosthetic heart valve implantation has increased slightly over the last 20 years in Denmark.

Funding Acknowledgement

Type of funding sources: None.

The impact of age on the 99th percentile of cardiac troponin

Introduction

The 99th percentile upper reference limit (URL) of cardiac troponin (cTn) is diagnostic cutoff for myocardial infarction (MI). Several factors are known to lead to an increase in cTn including sex, kidney function, left ventricular function and various comorbidities. Similarly, studies have shown that cTn concentration of patients increase with age. However, the impact of age on the concentration of cTn in healthy individuals is unclear as several studies of healthy populations showed little to no impact of age.

Purpose

To determine the effect of age on the URL of cTn for the Danish population.

Methods

We invited active and retired blood donors with the aim of including 250 participants of each sex in each of four age groups, <50, 50–60, 60–70 and >70 years, for a total of about 2000 participants. cTn levels were measured by 4 cTn assays (Siemens Atellica and Vista cTnI, Roche cTnT and Abbott Alinity cTnI). The age specific URL were calculated using the non-parametric method. Quantile regression for the 99th percentile was adjusted for sex and creatinine concentration.

Results

A total of 2287 participants were sampled in the study, of which 4 (0.2%) were excluded due to a history of heart disease and 7 (0.3%) were excluded due to insufficient plasma for screening biomarkers. The median age was 58.6 (IQR 48.2–69.7), and 52.6% were female. Figure 1 shows the distribution of cTn concentrations in age intervals. There was a significant increase in cTn with age for all assays (all p<0.001). After adjusting for sex and creatinine concentration, increasing age was only significantly associated with cTnT (0.40 ng/L increase per year, p=0.03). Figure 2 panel A shows the age specific URL for each assay, where we observed a significant difference for cTnT with the URL increasing from 15.8 ng/L (90% CI 12.4–33.9 ng/L) for participants <50 years to 37.6 ng/L (90% CI 34.6–41.5 ng/L) for participants >70 years. The proportion of participants with concentrations above the manufacturers URL increased with age for cTnT from 1.5% in participants <50 years to 25.6% for participants >70 years (p<0.001), figure 2 panel B. This changed little when removing participants with decreased kidney function (eGFR <60 mL/min/1.73 m2) as 24.3% of the remaining participants >70 years had a cTnT above the URL.

Conclusions

The concentration of cTn increased with age for all assays. This was clearest for cTnT in which the 99th percentiles of participants were significantly different for participants age >70 years of whom a quarter had cTnT levels above the level for myocardial injury according to the manufacturer's URL.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): HelsefondenMauritzen La Fountaine Foundation

Myocardial Work in Patients Hospitalized With COVID-19: Relation to Biomarkers, COVID-19 Severity, and All-Cause Mortality

Background COVID-19 infection has been hypothesized to affect left ventricular function; however, the underlying mechanisms and the association to clinical outcome are not understood. The global work index (GWI) is a novel echocardiographic measure of systolic function that may offer insights on cardiac dysfunction in COVID-19. We hypothesized that GWI was associated with disease severity and all-cause death in patients with COVID-19. Methods and Results In a multicenter study of patients admitted with COVID-19 (n=305), 249 underwent pressure-strain loop analyses to quantify GWI at a median time of 4 days after admission. We examined the association of GWI to cardiac biomarkers (troponin and NT-proBNP [N-terminal pro-B-type natriuretic peptide]), disease severity (oxygen requirement and CRP [C-reactive protein]), and all-cause death. Patients with elevated troponin (n=71) exhibited significantly reduced GWI (1508 versus 1707 mm Hg%; P=0.018). A curvilinear association to NT-proBNP was observed, with increasing NT-proBNP once GWI decreased below 1446 mm Hg%. Moreover, GWI was significantly associated with a higher oxygen requirement (relative increase of 6% per 100-mm Hg% decrease). No association was observed with CRP. Of the 249 patients, 37 died during follow-up (median, 58 days). In multivariable Cox regression, GWI was associated with all-cause death (hazard ratio, 1.08 [95% CI, 1.01-1.15], per 100-mm Hg% decrease), but did not increase C-statistics when added to clinical parameters. Conclusions In patients admitted with COVID-19, our findings indicate that NT-proBNP and troponin may be associated with lower GWI, whereas CRP is not. GWI was independently associated with all-cause death, but did not provide prognostic information beyond readily available clinical parameters. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04377035.

Loss of Nuclear Envelope Integrity and Increased Oxidant Production Cause DNA Damage in Adult Hearts Deficient in PKP2: A Molecular Substrate of ARVC

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by high propensity to life-threatening arrhythmias and progressive loss of heart muscle. More than 40% of reported genetic variants linked to ARVC reside in the PKP2 gene, which encodes the PKP2 protein (plakophilin-2).

METHODS

We describe a comprehensive characterization of the ARVC molecular landscape as determined by high-resolution mass spectrometry, RNA sequencing, and transmission electron microscopy of right ventricular biopsy samples obtained from patients with ARVC with PKP2 mutations and left ventricular ejection fraction >45%. Samples from healthy relatives served as controls. The observations led to experimental work using multiple imaging and biochemical techniques in mice with a cardiac-specific deletion of Pkp2 studied at a time of preserved left ventricular ejection fraction and in human induced pluripotent stem cell-derived PKP2-deficient myocytes.

RESULTS

Samples from patients with ARVC present a loss of nuclear envelope integrity, molecular signatures indicative of increased DNA damage, and a deficit in transcripts coding for proteins in the electron transport chain. Mice with a cardiac-specific deletion of Pkp2 also present a loss of nuclear envelope integrity, which leads to DNA damage and subsequent excess oxidant production (O2.- and H2O2), the latter increased further under mechanical stress (isoproterenol or exercise). Increased oxidant production and DNA damage is recapitulated in human induced pluripotent stem cell-derived PKP2-deficient myocytes. Furthermore, PKP2-deficient cells release H2O2 into the extracellular environment, causing DNA damage and increased oxidant production in neighboring myocytes in a paracrine manner. Treatment with honokiol increases SIRT3 (mitochondrial nicotinamide adenine dinucleotide-dependent protein deacetylase sirtuin-3) activity, reduces oxidant levels and DNA damage in vitro and in vivo, reduces collagen abundance in the right ventricular free wall, and has a protective effect on right ventricular function.

CONCLUSIONS

Loss of nuclear envelope integrity and subsequent DNA damage is a key substrate in the molecular pathology of ARVC. We show transcriptional downregulation of proteins of the electron transcript chain as an early event in the molecular pathophysiology of the disease (before loss of left ventricular ejection fraction <45%), which associates with increased oxidant production (O2.- and H2O2). We propose therapies that limit oxidant formation as a possible intervention to restrict DNA damage in ARVC.

Lung ultrasound findings in hospitalized COVID-19 patients in relation to venous thromboembolic events: the ECHOVID-19 study

PURPOSE

Several studies have reported thromboembolic events to be common in severe COVID-19 cases. We sought to investigate the relationship between lung ultrasound (LUS) findings in hospitalized COVID-19 patients and the development of venous thromboembolic events (VTE).

METHODS

A total of 203 adults were included from a COVID-19 ward in this prospective multi-center study (mean age 68.6 years, 56.7% men). All patients underwent 8-zone LUS, and all ultrasound images were analyzed off-line blinded. Several LUS findings were investigated (total number of B-lines, B-line score, and LUS-scores).

RESULTS

Median time from admission to LUS examination was 4 days (IQR: 2, 8). The median number of B-lines was 12 (IQR: 8, 18), and 44 (21.7%) had a positive B-line score. During hospitalization, 17 patients developed VTE (4 deep-vein thrombosis, 15 pulmonary embolism), 12 following and 5 prior to LUS. In fully adjusted multivariable Cox models (excluding participants with VTE prior to LUS), all LUS parameters were significantly associated with VTE (total number of B-lines: HR = 1.14, 95% CI (1.03, 1.26) per 1 B-line increase), positive B-line score: HR = 9.79, 95% CI (1.87, 51.35), and LUS-score: HR = 1.51, 95% CI (1.10, 2.07), per 1-point increase). The B-line score and LUS-score remained significantly associated with VTE in sensitivity analyses.

CONCLUSION

In hospitalized COVID-19 patients, pathological LUS findings were common, and the total number of B-lines, B-line score, and LUS-score were all associated with VTE. These findings indicate that the LUS examination may be useful in risk stratification and the clinical management of COVID-19. These findings should be considered hypothesis generating.

CLINICALTRIALS

GOV ID

NCT04377035.

SARS-CoV-2 surface swabs in locations with public access – potential for improved source control

The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on surfaces at public locations has been minimally described. By swab testing, we investigated the presence of SARS-CoV-2 on surfaces in public locations during the pandemic in February 2022. The viability of SARS-CoV-2 was not tested. Almost 25% of surfaces were positive for SARS-CoV-2; this was most pronounced in supermarkets.

Temporal Changes, Patient Characteristics, and Mortality, According to Microbiological Cause of Infective Endocarditis: A Nationwide Study

Background

Monitoring of microbiological cause of infective endocarditis (IE) remains key in the understanding of IE; however, data from large, unselected cohorts are sparse. We aimed to examine temporal changes, patient characteristics, and in‐hospital and long‐term mortality, according to microbiological cause in patients with IE from 2010 to 2017.

Methods and Results

Linking Danish nationwide registries, we identified all patients with first‐time IE. In‐hospital and long‐term mortality rates were assessed according to microbiological cause and compared using multivariable adjusted logistic regression analysis and Cox proportional hazard analysis, respectively. A total of 4123 patients were included. Staphylococcus aureus was the most frequent cause (28.1%), followed by Streptococcus species (26.0%), Enterococcus species (15.5%), coagulase‐negative staphylococci (6.2%), and “other microbiological causes” (5.3%). Blood culture–negative IE was registered in 18.9%. The proportion of blood culture–negative IE declined during the study period, whereas no significant changes were seen for any microbiological cause. Patients with Enterococcus species were older and more often had a prosthetic heart valve compared with other causes. For Streptococcus species IE, in‐hospital and long‐term mortality (median follow‐up, 2.3 years) were 11.1% and 58.5%, respectively. Compared with Streptococcus species IE, the following causes were associated with a higher in‐hospital mortality: S aureus IE (odds ratio [OR], 3.48 [95% CI, 2.74–4.42]), Enterococcus species IE (OR, 1.48 [95% CI, 1.11–1.97]), coagulase‐negative staphylococci IE (OR, 1.79 [95% CI, 1.21–2.65]), “other microbiological cause” (OR, 1.47 [95% CI, 0.95–2.27]), and blood culture–negative IE (OR, 1.99 [95% CI, 1.52–2.61]); and the following causes were associated with higher mortality following discharge (median follow‐up, 2.9 years): S aureus IE (hazard ratio [HR], 1.39 [95% CI, 1.19–1.62]), Enterococcus species IE (HR, 1.31 [95% CI, 1.11–1.54]), coagulase‐negative staphylococci IE (HR, 1.07 [95% CI, 0.85–1.36]), “other microbiological cause” (HR, 1.45 [95% CI, 1.13–1.85]), and blood culture–negative IE (HR, 1.05 [95% CI, 0.89–1.25]).

Conclusions

This nationwide study showed that S aureus was the most frequent microbiological cause of IE, followed by Streptococcus species and Enterococcus species. Patients with S aureus IE had the highest in‐hospital mortality.

Workforce attachment after a congenital long QT syndrome diagnosis: a Danish nationwide study

Objective

To examine workforce attachment among patients with congenital long QT syndrome (cLQTS) following diagnosis and identify factors associated with workforce attachment.

Methods and results

In this nationwide cohort study, all patients diagnosed with cLQTS in Denmark between 1996 and 2016 aged 18–60 years at diagnosis were identified using nationwide registries. Patients attached to the workforce at diagnosis were included. Attachment to the workforce 1 year after cLQTS diagnosis was examined and compared with a background population matched 1:4 on age, sex and employment status. Multiple logistic regression was performed to identify factors associated with 1-year workforce detachment among patients with cLQTS. 298 patients fulfilled the inclusion criteria. Six months after cLQTS diagnosis, 90.9% of patients with cLQTS were attached to the workforce compared with 95.0% in the background population (p=0.006 for difference). One year after diagnosis, 93.3% of patients with cLQTS were attached to the workforce compared with 93.8% in the background population (p=0.26). Among patients with cLQTS, a severe cLQTS disease manifestation was associated with workforce detachment 1 year after diagnosis (compared with asymptomatic patients; aborted cardiac arrest OR 20.4 (95% CI, 1.7 to 249.9); ventricular tachycardia/syncope OR 10.9 (95% CI, 1.1 to 110.5)). No other associated factors were identified.

Conclusions

More than 90% of patients with cLQTS remained attached to the workforce 1 year after diagnosis, which was similar to a matched background population. Patients with a severe cLQTS disease manifestation were less likely to be attached to the workforce 1 year after diagnosis.