Stem cell-derived cardiomyocyte heterogeneity confounds electrophysiological insights.

Human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) offer potential as an in vitro model for studying drug cardiotoxicity and patient-specific cardiovascular disease. The inherent electrophysiological heterogeneity of these cells limits the depth of insights that can be drawn from well-designed experiments. In this review, we provide our perspective on some sources and the consequences of iPSC-CM heterogeneity. We demonstrate the extent of heterogeneity in the literature and explain how such heterogeneity is exacerbated by patch-clamp experimental artifacts in the manual and automated set-up. Finally, we discuss how this heterogeneity, caused by both intrinsic and extrinsic factors, limits our ability to build digital twins of patient-derived cardiomyocytes.

Single-cell ionic current phenotyping elucidates non-canonical features and predictive potential of cardiomyocytes during automated drug experiments.

All new drugs must go through preclinical screening tests to determine their proarrhythmic potential. While these assays effectively filter out dangerous drugs, they are too conservative, often misclassifying safe compounds as proarrhythmic. In this study, we attempt to address this shortcoming with a novel, medium-throughput drug-screening approach: we use an automated patch-clamp system to acquire optimized voltage clamp (VC) and action potential (AP) data from human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) at several drug concentrations (baseline, 3×, 10× and 20× the effective free plasma concentrations). With our novel method, we show correlations between INa block and upstroke slowing after treatment with flecainide or quinine. Additionally, after quinine treatment, we identify significant reductions in current during voltage steps designed to isolate If and IKs. However, we do not detect any IKr block by either drug, and upon further investigation, do not see any IKr present in the iPSC-CMs when prepared for automated patch experiments (i.e. in suspension) - this is in contrast to similar experiments we have conducted with these cells using the manual patch setup. In this study, we: (1) present a proof-of-concept demonstration of a single-cell medium-throughput drug study, and (2) characterize the non-canonical electrophysiology of iPSC-CMs when prepared for experiments in a medium-throughput setting. KEY POINTS: Human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) offer potential as an in vitro model to study the proarrhythmic potential of drugs, but insights from these cells are often limited by the low throughput of manual patch-clamp. In this study, we use a medium-throughput automated patch-clamp system to acquire action potential (AP) and complex voltage clamp (VC) data from single iPSC-CMs at multiple drug concentrations. A correlation between AP upstroke and INa transients was identified and drug-induced changes in ionic currents found. We also characterize the substantially altered physiology of iPSC-CMs when patched in an automated system, suggesting the need to investigate differences between manual and automated patch experiments.

Optimization of a cardiomyocyte model illuminates role of increased INa,L in repolarization reserve.

Cardiac ion currents may compensate for each other when one is compromised by a congenital or drug-induced defect. Such redundancy contributes to a robust repolarization reserve that can prevent the development of lethal arrhythmias. Most efforts made to describe this phenomenon have quantified contributions by individual ion currents. However, it is important to understand the interplay between all major ion-channel conductances, as repolarization reserve is dependent on the balance between all ion currents in a cardiomyocyte. Here, a genetic algorithm was designed to derive profiles of nine ion-channel conductances that optimize repolarization reserve in a mathematical cardiomyocyte model. Repolarization reserve was quantified using a previously defined metric, repolarization reserve current, i.e., the minimum constant current to prevent normal action potential repolarization in a cell. The optimization improved repolarization reserve current up to 84% compared to baseline in a human adult ventricular myocyte model and increased resistance to arrhythmogenic insult. The optimized conductance profiles were not only characterized by increased repolarizing current conductances but also uncovered a previously unreported behavior by the late sodium current. Simulations demonstrated that upregulated late sodium increased action potential duration, without compromising repolarization reserve current. The finding was generalized to multiple models. Ultimately, this computational approach, in which multiple currents were studied simultaneously, illuminated mechanistic insights into how the metric's magnitude could be increased and allowed for the unexpected role of late sodium to be elucidated.NEW & NOTEWORTHY Genetic algorithms are typically used to fit models or extract desired parameters from data. Here, we use the tool to produce a ventricular cardiomyocyte model with increased repolarization reserve. Since arrhythmia mitigation is dependent on multiple cardiac ion-channel conductances, study using a comprehensive, unbiased, and systems-level approach is important. The use of this optimization strategy allowed us to find robust profiles that illuminated unexpected mechanistic determinants of key ion-channel conductances in repolarization reserve.

Single-cell ionic current phenotyping explains stem cell-derived cardiomyocyte action potential morphology.

Human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) are a promising tool to study arrhythmia-related factors, but the variability of action potential (AP) recordings from these cells limits their use as an in vitro model. In this study, we use recently published brief (10 s), dynamic voltage-clamp (VC) data to provide mechanistic insights into the ionic currents contributing to AP heterogeneity; we call this approach rapid ionic current phenotyping (RICP). Features of this VC data were correlated to AP recordings from the same cells, and we used computational models to generate mechanistic insights into cellular heterogeneity. This analysis uncovered several interesting links between AP morphology and ionic current density: both L-type calcium and sodium currents contribute to upstroke velocity, rapid delayed rectifier K+ current is the main determinant of the maximal diastolic potential, and an outward current in the activation range of slow delayed rectifier K+ is the main determinant of AP duration. Our analysis also identified an outward current in several cells at 6 mV that is not reproduced by iPSC-CM mathematical models but contributes to determining AP duration. RICP can be used to explain how cell-to-cell variability in ionic currents gives rise to AP heterogeneity. Because of its brief duration (10 s) and ease of data interpretation, we recommend the use of RICP for single-cell patch-clamp experiments that include the acquisition of APs.NEW & NOTEWORTHY We present rapid ionic current phenotyping (RICP), a current quantification approach based on an optimized voltage-clamp protocol. The method captures a rich snapshot of the ionic current dynamics, providing quantitative information about multiple currents (e.g., ICa,L, IKr) in the same cell. The protocol helped to identify key ionic determinants of cellular action potential heterogeneity in iPSC-CMs. This included unexpected results, such as the critical role of IKr in establishing the maximum diastolic potential.

Pulmonary arteriovenous malformations in patients with previous brain abscess: a cross-sectional population-based study.

BACKGROUND AND PURPOSE: Pulmonary arteriovenous malformations (PAVMs) may cause recurrent brain abscess. The primary aim was to determine the prevalence of PAVM amongst survivors of brain abscess. The proportion with cardiac right-to-left shunts was also assessed post hoc. METHODS: This was a cross-sectional population-based study of adult (≥18 years) survivors of cryptogenic bacterial brain abscess in Denmark from 2007 through 2016. Patients were invited for bubble-echocardiography to detect vascular right-to-left shunting and, if abnormal, subsequent computed tomography thorax for diagnosis of PAVM. Data are presented as n/N (%) or median with interquartile range (IQR). RESULTS: Study participation was accepted by 47/157 (30%) eligible patients amongst whom two did not appear for scheduled bubble-echocardiography. The median age of participants was 54 years (IQR 45-62) and 19/57 (33%) were females compared with 59 years (IQR 48-68, p = 0.05) and 41/85 females (48%, p = 0.22) in non-participants. Bubble-echocardiography was suggestive of shunt in 10/45 (22%) participants and PAVM was subsequently confirmed by computed tomography in one patient with grade 1 shunting. The corresponding prevalence of PAVM was 2% (95% confidence interval 0.06-11.8) amongst all examined participants. Another 9/45 (20%) were diagnosed with patent in persistent foramen ovale (n = 8) or atrial septum defect (n = 1), which is comparable with the overall prevalence of 25% amongst adults in the Danish background population. CONCLUSIONS: Undiagnosed PAVM amongst adult survivors of cryptogenic bacterial brain abscess is rare but may be considered in select patients. The prevalence of cardiac right-to-left shunts amongst brain abscess patients corresponds to the prevalence in the general population.

The Danish Aging and Cognition (DanACo) cohort.

BACKGROUND: With aging populations worldwide, identification of predictors of age-related cognitive decline is becoming increasingly important. The Danish Aging and Cognition Cohort (DanACo) including more than 5000 Danish men was established to investigate predictors of age-related cognitive decline from young adulthood to late mid-life. CONSTRUCTION AND CONTENT: The DanACo cohort was established through two separate data collections with identical designs involving a follow-up examination in late mid-life of men for whom intelligence test scores were available from their mandatory conscription board examination. The cohort consists of 5,183 men born from 1949 through 1961, with a mean age of 20.4 years at baseline and a mean age of 64.4 years at follow-up. The baseline measures consisted of height, weight, intelligence test score and educational level collected at the conscription board examination. The follow-up assessment consisted of a re-administration of the same intelligence test and a comprehensive questionnaire covering socio-demographic factors, lifestyle, and health-related factors. The data were collected in test sessions with up to 24 participants per session. Using the unique personal identification number assigned to all Danes, the cohort has been linked to data from national administrative and health registers for prospectively collected data on socioeconomic and health-related factors. UTILITY AND DISCUSSION: The DanACo cohort has some major strengths compared to existing cognitive aging cohorts such as a large sample size (n = 5,183 men), a validated global measure of cognitive ability, a long retest interval (mean 44.0 years) and the availability of prospectively collected data from registries as well as comprehensive questionnaire data. The main weakness is the low participation rate (14.3%) and that the cohort consists of men only. CONCLUSION: Cognitive decline is a result of a summary of factors across the life-course. The DanACo cohort is characterized by a long retest interval and contains data on a wealth of factors across adult life which is essential to establish evidence on predictors of cognitive decline. Moreover, the size of the cohort ensures sufficient statistical power to identify even relatively weak predictors of cognitive decline.

Mobile device screen time is associated with poorer language development among toddlers: results from a large-scale survey.

BACKGROUND: Despite young children's widespread use of mobile devices, little research exists on this use and its association with children's language development. The aim of this study was to examine the associations between mobile device screen time and language comprehension and expressive language skills. An additional aim was to examine whether three factors related to the domestic learning environment modify the associations. METHODS: The study uses data from the Danish large-scale survey TRACES among two- and three-year-old children (n = 31,125). Mobile device screen time was measured as time spent on mobile devices on a normal day. Measurement of language comprehension and expressive language skills was based on subscales from the Five to Fifteen Toddlers questionnaire. Multivariable linear regression was used to examine the association between child mobile device screen time and language development and logistic regression to examine the risk of experiencing significant language difficulties. Joint exposure analyses were used to examine the association between child mobile device screen time and language development difficulties in combination with three other factors related to the domestic learning environment: parental education, reading to the child and child TV/PC screen time. RESULTS: High mobile device screen time of one hour or more per day was significantly associated with poorer language development scores and higher odds for both language comprehension difficulties (1-2 h: AOR = 1.30; ≥ 2 h: AOR = 1.42) and expressive language skills difficulties (1-2 h: AOR = 1.19; ≥ 2 h: AOR = 1.46). The results suggest that reading frequently to the child partly buffers the negative effect of high mobile device screen time on language comprehension difficulties but not on expressive language skills difficulties. No modifying effect of parental education and time spent by the child on TV/PC was found. CONCLUSIONS: Mobile device screen time of one hour or more per day is associated with poorer language development among toddlers. Reading frequently to the child may have a buffering effect on language comprehension difficulties but not on expressive language skills difficulties.

The iceberg model of suicidal ideation and behaviour in Danish adolescents: integration of national registry and self-reported data within a national birth cohort.

Hospital records are used to identify suicide attempts in many countries but not all individuals present to hospital after a suicide attempt i.e., suggesting a 'hidden number'. Our aim was to present the prevalence of suicide ideation, plans, attempts, and suicides among Danish adolescents, including attempts not resulting in hospital contact. The study population consisted of participants in the Danish National Birth Cohort participating in an 18-year follow-up, with individual-level linkage to national register data. Prevalence was estimated with a variable with mutually exclusive categories ranging from no suicidality to self-reported suicide ideation, -plans, -attempt and hospital-recorded suicide attempt and stratified on sex and parental income. The 'hidden number' was estimated as the ratio between suicide attempts with and without hospital contact. Among 47 858 participants, all aged 18-years, 36% girls and 28% boys reported suicide ideation at least once in their life. In addition, 6% girls and 3% boys had either reported or been recorded with a suicide attempt. For every attempt recorded in the hospital setting, two girls (ratio, 1:2) and six boys (ratio, 1:6) reported having attempted suicide without hospital contact. The prevalence of any suicide attempt was 8% and 3% in the lowest and highest income group, respectively. Before age 18, 0·011% girls and 0·016% boys had died by suicide. In conclusion, suicidal ideation and behaviour are common in adolescents and there is a substantial 'hidden number' of adolescents with suicide attempt. These results emphasize the need for early age suicide preventive interventions in community-settings e.g., school environments.

Diversity of cells and signals in the cardiovascular system.

This white paper is the outcome of the seventh UC Davis Cardiovascular Research Symposium on Systems Approach to Understanding Cardiovascular Disease and Arrhythmia. This biannual meeting aims to bring together leading experts in subfields of cardiovascular biomedicine to focus on topics of importance to the field. The theme of the 2022 Symposium was 'Cell Diversity in the Cardiovascular System, cell-autonomous and cell-cell signalling'. Experts in the field contributed their experimental and mathematical modelling perspectives and discussed emerging questions, controversies, and challenges in examining cell and signal diversity, co-ordination and interrelationships involved in cardiovascular function. This paper originates from the topics of formal presentations and informal discussions from the Symposium, which aimed to develop a holistic view of how the multiple cell types in the cardiovascular system integrate to influence cardiovascular function, disease progression and therapeutic strategies. The first section describes the major cell types (e.g. cardiomyocytes, vascular smooth muscle and endothelial cells, fibroblasts, neurons, immune cells, etc.) and the signals involved in cardiovascular function. The second section emphasizes the complexity at the subcellular, cellular and system levels in the context of cardiovascular development, ageing and disease. Finally, the third section surveys the technological innovations that allow the interrogation of this diversity and advancing our understanding of the integrated cardiovascular function and dysfunction.

Association between SARS-CoV-2 infection and self-harm: Danish nationwide register-based cohort study.

BACKGROUND: Case studies have linked SARS-CoV-2 infection to suicidal behaviour. However, conclusive evidence is lacking. AIMS: To examine whether a history of SARS-CoV-2 infection or SARS-CoV-2-related hospital admission was associated with self-harm in the general population and in high-risk groups. METHOD: A cohort design was applied to nationwide data on all people aged ≥15 years and living in Denmark between 27 February 2020 and 15 October 2021. Exposure was identified as having had a positive SARS-CoV-2 PCR test, and further assessed as SARS-CoV-2-related hospital admission. Rates of probable self-harm were examined using adjusted incidence rate ratios (aIRRs). The following subgroups were identified: (a) lower educational level, (b) chronic medical conditions, (c) disability pension, (d) mental disorders, (e) substance use disorders, and history of (f) homelessness and (g) imprisonment. RESULTS: Among 4 412 248 included individuals, 260 663 (5.9%) had tested positive for SARS-CoV-2. Out of 5453 individuals presenting with self-harm, 131 (2.4%) had been infected. Individuals with a history of a positive SARS-CoV-2 test result had an aIRR for self-harm of 0.86 (95% CI 0.72-1.03) compared with those without. High rates were found after a SARS-CoV-2-related hospital admission (aIRR = 7.68; 95% CI 5.61-10.51) or a non-SARS-CoV-2-related admission (aIRR = 10.27; 95% CI 9.65-10.93) versus non-infected and not admitted. In sensitivity analyses with a more restrictive definition of self-harm, a positive PCR test was associated with lower rates of self-harm. CONCLUSIONS: Individuals with a PCR-confirmed SARS-CoV-2 infection did not have higher rates of self-harm than those without. Hospital admission in general, rather than being SARS-CoV-2 positive. seemed to be linked to elevated rates of self-harm.

Traumatic brain injury and risk of subsequent attempted suicide and violent crime.

BACKGROUND: Traumatic brain injury (TBI) can cause long-lasting sequelae that may increase the risk of suicidal or criminal behaviour, but large-scale longitudinal studies are lacking on the link between TBI and events of suicide attempt and violent crime. This study examined the incidence of suicide attempt and violent crime following hospital contact for TBI in a nationwide cohort study. METHODS: We used nationwide register data covering all individuals aged 10+ living in Denmark during 1980-2016 (n = 7 783 951). Of these, 587 522 individuals had a hospital contact for TBI. Incidence rate ratios (IRR) were calculated by Poisson regression analyses while adjusted for relevant covariates including other fractures and psychiatric diagnoses. RESULTS: Individuals with TBI had higher rates of suicide attempt (females IRR, 2.78; 95% CI 2.71-2.85; males IRR, 3.00; 95% CI 2.93-3.08) compared to individuals without TBI in adjusted analyses. Multiple TBI and temporal proximity to TBI were associated with higher rates of suicide attempt. Individuals with TBI had higher rates of violent crime (females IRR, 2.43; 95% CI 2.36-2.49; males IRR, 1.80, 95% CI 1.78-1.82) compared with individuals without TBI. Higher rates of violent crime were found after multiple TBI and temporal proximity to TBI. CONCLUSIONS: This nationwide cohort study found higher rates of suicide attempt and violent crime among individuals with prior hospital diagnosed TBI, compared with individuals without TBI. This emphasises the need for preventive efforts immediately after TBI diagnosis, which might mitigate the risks of a trajectory toward suicidal or violent behaviours.

Prediction models of suicide and non-fatal suicide attempt after discharge from a psychiatric inpatient stay: A machine learning approach on nationwide Danish registers.

INTRODUCTION: To develop machine learning models capable of predicting suicide and non-fatal suicide attempt as separate outcomes in the first 30 days after discharge from a psychiatric inpatient stay. METHODS: Prospective cohort study using nationwide Danish registry data. We included individuals who were 18 years or older, and all discharges from psychiatric hospitalizations in Denmark from 1995 to 2018. We trained predictive models using 10-fold cross validation on 80% of the data and did testing on the remaining 20%. RESULTS: The best model for predicting non-fatal suicide attempt was an ensemble of predictions from gradient boosting (XGBoost) and categorical boosting (catBoost). The ROC-AUC for predicting suicide attempt was 0.85 (95% CI: 0.84-0.85). At a risk threshold of 4.36%, positive predictive value (PPV) was 11.0% and sensitivity was 47.2%. The best model for predicting suicide was an ensemble of predictions from random forest, XGBoost and catBoost. For suicide, the ROC-AUC was 0.71 (95% CI: 0.70-0.73). At a risk threshold of 0.15%, PPV was 0.34% and sensitivity was 56.0%. The most contributing predictors differed when predicting suicide and suicide attempt, indicating that separate models are needed. The ensemble model was fair across sex and age, and more so than the penalized logistic regression model. CONCLUSIONS: We achieved good performance for predicting suicide attempts and demonstrated a clinical application of ensemble models. Our results indicate a difference in predictive performance for models predicting suicide and suicide attempt, respectively. Thus, we recommend that suicide and suicide attempt are treated as two separate endpoints, in particular for clinical application. We demonstrated that the ensemble model is fairer across sex and age compared with a penalized logistic regression, and therefore we recommend the use of well-tested ensembles despite a more complex explainability.

Leak current, even with gigaohm seals, can cause misinterpretation of stem cell-derived cardiomyocyte action potential recordings.

AIMS: Human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) have become an essential tool to study arrhythmia mechanisms. Much of the foundational work on these cells, as well as the computational models built from the resultant data, has overlooked the contribution of seal-leak current on the immature and heterogeneous phenotype that has come to define these cells. The aim of this study is to understand the effect of seal-leak current on recordings of action potential (AP) morphology. METHODS AND RESULTS: Action potentials were recorded in human iPSC-CMs using patch clamp and simulated using previously published mathematical models. Our in silico and in vitro studies demonstrate how seal-leak current depolarizes APs, substantially affecting their morphology, even with seal resistances (Rseal) above 1 GΩ. We show that compensation of this leak current is difficult due to challenges with obtaining accurate measures of Rseal during an experiment. Using simulation, we show that Rseal measures (i) change during an experiment, invalidating the use of pre-rupture values, and (ii) are polluted by the presence of transmembrane currents at every voltage. Finally, we posit that the background sodium current in baseline iPSC-CM models imitates the effects of seal-leak current and is increased to a level that masks the effects of seal-leak current on iPSC-CMs. CONCLUSION: Based on these findings, we make recommendations to improve iPSC-CM AP data acquisition, interpretation, and model-building. Taking these recommendations into account will improve our understanding of iPSC-CM physiology and the descriptive ability of models built from such data.

Genotype-phenotype correlation in arrhythmogenic right ventricular cardiomyopathy-risk of arrhythmias and heart failure.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is predominantly caused by desmosomal genetic variants, and clinical hallmarks include arrhythmias and systolic dysfunction. We aimed at studying the impact of the implicated gene(s) on the disease course. METHODS: The Nordic ARVC Registry holds data on a multinational cohort of ARVC families. The effects of genotype on electrocardiographic features, imaging findings and clinical events were analysed. RESULTS: We evaluated 419 patients (55% men), with a mean follow-up of 11.2±7.4 years. A pathogenic desmosomal variant was identified in 62% of the 230 families: PKP2 in 41%, DSG2 in 13%, DSP in 7% and DSC2 in 3%. Reduced left ventricular ejection fraction (LVEF) ≤45% on cardiac MRI was more frequent among patients with DSC2/DSG2/DSP than PKP2 ARVC (27% vs 4%, p<0.01). In contrast, in Cox regression modelling of patients with definite ARVC, we found a higher risk of arrhythmias among PKP2 than DSC2/DSG2/DSP carriers: HR 0.25 (0.10-0.68, p<0.01) for atrial fibrillation/flutter, HR 0.67 (0.44-1.0, p=0.06) for ventricular arrhythmias and HR 0.63 (0.42-0.95, p<0.05) for any arrhythmia. Gene-negative patients had an intermediate risk (16%) of LVEF ≤45% and a risk of the combined arrhythmic endpoint comparable with DSC2/DSG2/DSP carriers. Male sex was a risk factor for both arrhythmias and reduced LVEF across all genotype groups (p<0.01). CONCLUSION: In this large cohort of ARVC families with long-term follow-up, we found PKP2 genotype to be more arrhythmic than DSC2/DSG2/DSP or gene-negative carrier status, whereas reduced LVEF was mostly seen among DSC2/DSG2/DSP carriers. Male sex was associated with a more severe phenotype.

The effect of the SAFE intervention on post-discharge suicidal behavior: a quasi-experimental study using propensity score matching.

OBJECTIVES: The risk of suicidal behavior after discharge from psychiatric admission is high. The aim of this study was to examine whether the SAFE intervention, an implementation of a systematic safer discharge procedure, was associated with a reduction in suicidal behavior after discharge. METHODS: The SAFE intervention was implemented at Mental Health Center Copenhagen in March 2018 and consisted of three systematic discharge procedures: (1) A face-to-face meeting between patient and outpatient staff prior to discharge, (2) A face-to-face meeting within the first week after discharge, and (3) Involvement of relatives. Risk of suicide attempt at six-month post-discharge among patients discharged from the SAFE intervention was compared with patients discharged from comparison mental health centers using propensity score matching. RESULTS: 7604 discharges took place at the intervention site, which were 1:1 matched with discharges from comparison sites. During the six months of follow-up, a total of 570 suicide attempts and 25 suicides occurred. The rate of suicide attempt was 11,652 per 100,000 person-years at the SAFE site, while it was 10,530 at comparisons sites. No observable difference in suicide attempt 1.10 (95% CI: 0.89-1.35) or death by suicide (OR = 1.27; 95% CI:0.58-2.81) was found between sites at 6-month follow-up. CONCLUSION: No difference in suicidal behavior between the sites was found in this pragmatic study. High rates of suicidal behavior were found during the 6-months discharge period, which could suggest that a preventive intervention should include support over a longer post-discharge period than the one-week follow-up offered in the SAFE intervention.

Partial Oral versus Intravenous Antibiotic Treatment of Endocarditis.

BACKGROUND: Patients with infective endocarditis on the left side of the heart are typically treated with intravenous antibiotic agents for up to 6 weeks. Whether a shift from intravenous to oral antibiotics once the patient is in stable condition would result in efficacy and safety similar to those with continued intravenous treatment is unknown. METHODS: In a randomized, noninferiority, multicenter trial, we assigned 400 adults in stable condition who had endocarditis on the left side of the heart caused by streptococcus, Enterococcus faecalis, Staphylococcus aureus, or coagulase-negative staphylococci and who were being treated with intravenous antibiotics to continue intravenous treatment (199 patients) or to switch to oral antibiotic treatment (201 patients). In all patients, antibiotic treatment was administered intravenously for at least 10 days. If feasible, patients in the orally treated group were discharged to outpatient treatment. The primary outcome was a composite of all-cause mortality, unplanned cardiac surgery, embolic events, or relapse of bacteremia with the primary pathogen, from the time of randomization until 6 months after antibiotic treatment was completed. RESULTS: After randomization, antibiotic treatment was completed after a median of 19 days (interquartile range, 14 to 25) in the intravenously treated group and 17 days (interquartile range, 14 to 25) in the orally treated group (P=0.48). The primary composite outcome occurred in 24 patients (12.1%) in the intravenously treated group and in 18 (9.0%) in the orally treated group (between-group difference, 3.1 percentage points; 95% confidence interval, -3.4 to 9.6; P=0.40), which met noninferiority criteria. CONCLUSIONS: In patients with endocarditis on the left side of the heart who were in stable condition, changing to oral antibiotic treatment was noninferior to continued intravenous antibiotic treatment. (Funded by the Danish Heart Foundation and others; POET ClinicalTrials.gov number, NCT01375257 .).

Intergenerational transmission of suicide attempt in a cohort of 4.4 million children.

BACKGROUND: The association between suicide attempts (SAs) in parents and children is unclear, and risk indicators for intergenerational transmission remain undocumented. We aimed to assess this association, considering the child's developmental period at the time of parents' attempted suicide, and the parental relation. METHODS: Using a prospective cohort design, nationwide population data were linked to the Psychiatric Central Register and National Patient Register for all individuals aged 10 years or older living in Denmark between 1980 and 2016. We assessed incidence rate ratios (IRRs) and cumulative hazards for children's first SA. RESULTS: In a cohort of 4 419 651 children, 163 056 (3.7%) had experienced a parental SA. An SA was recorded among 6996 (4.3%) of the exposed children as opposed to 70112 (1.6%) in unexposed individuals. Higher rates were noted when a parental SA occurred during early childhood (0 ⩽ age < 2) [IRR, 4.7; 95% confidence interval (CI) 4.2-5.4] v. late childhood (6 ⩽ age < 13) (IRR, 3.6; 95% CI 3.4-3.8) when compared to those unexposed. Children exposed prior to age 2 had the highest rates of all sub-groups when reaching age 13-17 (IRR, 6.5; 95% CI 6.0-7.1) and 18-25 years (IRR, 6.8; 95% CI 6.2-7.4). Maternal SA (IRR, 3.4; 95% CI 3.2-3.5) was associated with higher rates than paternal (IRR, 2.8; 95% CI 2.7-2.9). CONCLUSION: Parental SA was associated with children's own SA. Exposure during early developmental stages was associated with the highest rates. Early preventive efforts are warranted as is monitoring of suicide risk in the children from age 13.

Complications of implantable cardioverter-defibrillator treatment in arrhythmogenic right ventricular cardiomyopathy.

AIMS: Treatment with implantable cardioverter-defibrillators (ICD) is a cornerstone for prevention of sudden cardiac death in arrhythmogenic right ventricular cardiomyopathy (ARVC). We aimed at describing the complications associated with ICD treatment in a multinational cohort with long-term follow-up. METHODS AND RESULTS: The Nordic ARVC registry was established in 2010 and encompasses a large multinational cohort of ARVC patients, including their clinical characteristics, treatment, and events during follow-up. We included 299 patients (66% males, median age 41 years). During a median follow-up of 10.6 years, 124 (41%) patients experienced appropriate ICD shock therapy, 28 (9%) experienced inappropriate shocks, 82 (27%) had a complication requiring surgery (mainly lead-related, n = 75), and 99 (33%) patients experienced the combined endpoint of either an inappropriate shock or a surgical complication. The crude rate of first inappropriate shock was 3.4% during the first year after implantation but decreased after the first year and plateaued over time. Contrary, the risk of a complication requiring surgery was 5.5% the first year and remained high throughout the study period. The combined risk of any complication was 7.9% the first year. In multivariate cox regression, presence of atrial fibrillation/flutter was a risk factor for inappropriate shock (P < 0.05), whereas sex, age at implant, and device type were not (all P > 0.05). CONCLUSION: Forty-one percent of ARVC patients treated with ICD experienced potentially life-saving ICD therapy during long-term follow-up. A third of the patients experienced a complication during follow-up with lead-related complications constituting the vast majority.

Is vegetation cover in key behaviour settings important for early childhood socioemotional function? A preregistered, cross-sectional study.

The environmental influences on early childhood development are understudied. The association between vegetation cover (i.e., trees, shrubs, grassed areas) in four key behaviour settings and socioemotional functioning was investigated in 1196 young children (2-5 years). Emotional difficulties were inversely associated with vegetation cover in the home yard (OR: 0.81 [0.69-0.96]) and neighbourhood (OR: 0.79 [0.67-0.94]), but not in early childhood education and care (ECEC) centre outdoor areas or the ECEC neighbourhood. The higher odds of emotional difficulties associated with lower levels of maternal education was reduced with higher percentages of home yard vegetation cover. There was no evidence of mediation of the relationship between emotional difficulties and vegetation cover by time spent playing outside the home, day or nighttime sleep duration, or physical activity. We found no associations between vegetation cover and conduct, hyperactivity and inattention, peer difficulties, or prosocial behaviours. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=J3HeEiIjVZc.

Self-assessed health status and associated mortality in endocarditis: secondary findings from the POET trial.

PURPOSE: Self-assessed poor health status is associated with increased risk of mortality in several cardiovascular conditions, but has not been investigated in patients with endocarditis. We examined health status and mortality in patients with endocarditis. METHODS: This is a re-specified substudy of the randomized POET endocarditis trial, which included 400 patients. Patients completed the single-question self-assessed health status from the Short-Form 36 questionnaire at time of randomization and were categorized as having poor or non-poor (excellent/very good, good, or fair) health status. Self-assessed health status and all-cause mortality were examined by a Cox regression model. RESULTS: Self-assessed health status was completed by 266 (67%) patients with a mean age of 68.0 years (± 11.8), 54 (20%) were females, and 86 (32%) had one or more major concurrent medical conditions besides endocarditis. The self-assessed health status distribution was poor (n = 21, 8%) and non-poor (n = 245, 92%). The median follow-up was 3.3 years and death occurred in 9 (43%) and 48 (20%) patients reporting poor and non-poor health status, respectively, and mortality rates [mortality/100 person-years, 95% confidence interval (CI)] were 18.1 (95% CI 9.4-34.8) and 5.4 (95% CI 4.1-7.2), i.e., the crude hazard ratio for death was 3.4 (95% CI: 1.7-7.0, p < 0.01). CONCLUSION: Self-assessed poor health status compared with non-poor health status as assessed by a single question was associated with a threefold increased long-term mortality in patients with endocarditis. POET ClinicalTrials.gov number, NCT01375257. TRIAL REGISTRY: POET ClinicalTrials.gov number, NCT01375257.