bluuebunny/crossref_metadata_2025_split huggingface dataset:
Founder effect may offer protection from ischemic heart disease in the South-Brazilian Mennonites
Authors: Da Rocha G , Vieira Junior W A , Meissner C G , Oliveira L C , Dos Santos P I , Da Silva M A , Hauser A B , McMahon F , Lopes F L , Lima Junior E , Boldt A W B 
Published: October 2022

Abstract

Introduction
The Mennonites are an Anabaptist population originated in Europe around 500 years ago. They are a relatively isolated population, established in Brazil in 1930, which suffered three bottleneck effects that reduced their genetic variability and may increase the frequency of diseases.

Purpose
We aimed to clarify the genetic epidemiology of heart disease in this population.

Methods
Epidemiological, biometrical and lipidogram data were collected from 2016 to 2020, based on an adapted questionnaire of the Brazilian National Health Research. In total, 485 Mennonites (MEN) and 45 non-Mennonites from three different settlements in Curitiba, Witmarsum, and Colônia Nova (CON) were enrolled in the study. DNA was extracted from blood and 104 exomes from CON, sequenced to &gt;30x coverage.

Results
The prevalence of hypertension (20.5 vs. 31.8%, p&lt;0.001) and dyslipidemia (41.1% vs. 65.1%, p&lt;0.001) were lower compared to Germans (GER). When compared to Brazilians (BRA), dyslipidemia was higher in Mennonites (23% vs. 41.3%, p&lt;0.001) and hypertension was higher in Brazilians (20.5% vs. 25.7%, p=0.02). The prevalence of overweight among the three populations doesn't have a significant statistical difference (59% MEN, 55.7% BRA, 59.7% GER, p=0.09). Myocardial infarction (MI) prevalence is drastically different between the three (0.6% MEN, 7.1% BR, 4.7% GER, p&lt;0.001). The immigration route had an impact on the cardiovascular disease (CVD) risk when adjusted to, hypertension, sex, first degree relative with CVD, and age. The more extenuating the immigration route of the Mennonites, the higher is the CVD risk (OR 1.57, IC95 1.22–2.03, p=0.001). Forty-five variants of 35 genes were associated with a dominant effect for CVD (p&lt;0.01) independently of sex, age, body mass index, and weekly physical activity. Between those, 38 are known to be associated with mRNA levels on heart/arteries (eQTLs in GTEX), 14 are missense mutations, one causes a frameshift and 18 destroy or create CpG sites with a possible epigenetic effect. The frequency of 14 out 16 alleles differed from non-Finish Europeans and Brazilians, indicating a possible founder effect. Eight are associated with CVD protection (p&lt;0.001). These variants are related to less inflammation of atherosclerotic plaques.

Conclusion
The South-Brazilian Mennonite population seems to have some kind of protection for ischemic heart disease, which may rely on founder effects that raised the frequencies of protective alleles.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): CAPES for PROAP finance Code 001, and scholarships for WAVJ and LCO. ABWB receives a research productivity scholarship from CNPq (protocol 314288/2018-0).
Generation of mature compact ventricular cardiomyocytes from human pluripotent stem cells
Authors: Funakoshi S , Keller G K 
Published: October 2022

Abstract

Introduction
Compact cardiomyocytes that make up the ventricular wall of the adult heart represent an important therapeutic target population for modeling and treating cardiovascular diseases. Although human pluripotent stem cell (hPSC) represents a promising source to generate target cells in vitro, there has been no optimal protocols to generate mature compact cardiomyocytes derived from hPSCs.

Purpose
To establish the protocol to generate mature compact ventricular cardiomyocytes derived from hPSCs.

Methods
By mimicking the early ventricular development and postnatal maturation process observed in the heart in vivo, we searched for the specific factors to induce compact lineage and promote their maturation level.

Results
We established a differentiation strategy that promotes the specification, proliferation and maturation of compact ventricular cardiomyocytes from hPSCs. The treatment of Wnt signaling activator, CHIR, and IGF2 significantly increased the expression level of a compact marker, MYCN (p=0.006), and suppressed the trabecular markers, NPPA (p=0.0117) and BMP10 (p=0.0032). Those factors induced a proliferation of compact cardiomyocytes by two folds (p&lt;0.0001). Additionally, we identified that the combination of PPARα agonist, dexamethasone, T3 hormone, and palmitate in the low glucose containing media following the compact specification period significantly induced the fatty acid transporter, CD36, in the compact cardiomyocytes (p&lt;0.0001). The CD36-positive compact cardiomyocytes generated under these conditions displayed the ability to use fatty acids as an energy source, a high mitochondrial mass, well-defined sarcomere structures and enhanced contraction force. These mature compact cardiomyocytes showed metabolic changes indicative of those associated with heart failure when challenged in vitro with pathological stimuli and were found to generate grafts consisting of more mature cells than those derived from immature cardiomyocytes following transplantation into infarcted rat hearts.

Conclusions
We successfully generated the mature compact cardiomyocytes derived from hPSCs. These findings highlight the power of recapitulating key aspects of embryonic and postnatal development for generating therapeutically relevant cell types from hPSCs.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Canadian Institutes of Health Research (CIHR)
High prevalence of deleterious variants in cardiomyopathy genes in patients with early onset atrial fibrillation
Authors: Vad O B , Ahlberg G , Paludan-Muller C , Refsgaard L , Sajadieh A , Haunsoe S , Bundgaard H , Svendsen J H , Olesen M S 
Published: October 2022

Abstract

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 &lt;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
Temporal trends and outcomes in ST-segment elevation myocardial infarction: a cardiac magnetic resonance imaging study over the course of 15 years
Authors: Lechner I , Reindl M , Tiller C , Holzknecht M , Fink P , Troger F , Mayr A , Klug G , Bauer A , Reinstadler S J , Metzler B 
Published: October 2022

Abstract

Aims
Development of evidence-based treatments in ST-elevation myocardial infarction (STEMI) patients during the last 30 years have been associated with improved outcome; however, there are data suggesting a plateauing since around 2008 (1). Moreover, contemporary data are very scarce regarding the temporal trends of infarct outcomes. This study sought to describe the temporal trends in infarct severity at myocardial tissue level over the course of 15 years by means of cardiac magnetic resonance imaging (MRI).

Methods
This study analyzed STEMI patients treated with percutaneous coronary intervention (PCI) in our Medical University who underwent a cardiac MRI between 2005 and 2021. The 15-year study period was divided into sequential 2-years blocks. Infarct characteristics were measured using MRI at 3 days [IQR 2–5] after PCI.

Results
A total of 844 STEMI patients (17% female) with a median age of 57 (interquartile range [IQR]: 51–66) years were included. The rate of evidence-based treatments was high for aspirin (99%), P2Y12i (99%), beta-blockers (91%), ACEi/ATi (92%) and statins (100%) and did not change significantly over the study period (p&gt;0.05) with the exception for ACEi/ATi (p=0.03) and prasugrel (p&lt;0.001), which increased and clopidogrel, which decreased during the study course (p&lt;0.001). TIMI risk score did not change over the study period (p=0.43). Overall median infarct size was 16 [9–25]% and did not change (p=0.39) significantly. MVO, a marker of severe reperfusion injury, was also comparable (p=0.16). Accordingly, LV ejection fraction remained virtually unchanged (p=0.23)

Conclusion
Although further implementation of evidence-based treatments was seen also during the last 15 years, there has been no effect on infarct size, reperfusion injury and LV ejection fraction for patients who undergo primary PCI due to STEMI. Novel treatment strategies are needed to address this unmet therapeutic need.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Austrian Science Fund (FWF)Austrian Society of Cardiology
Homozygosity predominantly affects hypertrophic cardiomyopathy minor genes in an Egyptian clinical cohort
Authors: Allouba M , Walsh R , Afify A , Halawa S , Galal A , Hosny M , Fathy M , Theotokis P , Whiffin N , Anwar S , Elguindy A , Ware J , Barton P , Aguib Y , Yacoub M 
Published: October 2022

Abstract

Background
Consanguinity is prevalent in Egypt (35%) resulting in a high incidence of homozygosity. The influence of homozygosity on the genetics of Hypertrophic Cardiomyopathy (HCM) has not been adequately studied.

Purpose
The purpose of this study is to define the genetic architecture of HCM in Egypt using ethnically-matched case and control cohorts.

Methods
Prospective Egyptian patients (n=514) and controls (n=400) were recruited to Aswan Heart Centre for clinical phenotyping and genetic testing for 174 genes implicated in inherited cardiac conditions (Illumina). Rare variation (gnomAD filtering allele frequency ≤4x10–5) in 13 validated HCM genes were classified according to the American College of Medical Genetics (ACMG) guidelines and compared with a prospective HCM cohort of predominantly European ancestry (n=684).

Results
Significantly fewer rare variants detected in Egyptian patients could be classified as (likely) pathogenic compared to Europeans (40.8% vs. 61.6%, p-value=1.6x10–5). Incorporating analysis from these Egyptian case-control cohorts into the ACMG guidelines increased this yield to 53.8%. Homozygous variants were more frequently observed in Egyptian patients (4.1% vs 0.1%, p-value=2x10–7), with variants in the minor HCM genes MYL2, MYL3 and CSRP3 more likely to present in homozygosity than the major genes (MYH7, MYBPC3 and troponins), suggesting such variants are less penetrant in the heterozygous state.

Conclusions
The integration of Egyptian-specific genetic and phenotypic data significantly improves variant interpretation in HCM and consequently the precision of genetic testing. The observed prevalence of homozygosity and rare variation in minor HCM genes in Egyptian patients provides important insights into its disease-mechanisms and genetics.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Science and Technology Development FundAl Alfi Foundation
An emerging role for DPP6: reciprocal regulation of INa-Ito and implications for arrhythmogenesis
Authors: Rossetti A , Spatjens R L H , Kammerer S , Stoks J , Firneburg R , Seyen S R , Helderman-Van Den Enden A T J M , Wilde A A M , Loeys B L , Saenen J , Heijman J , Volders P G A 
Published: October 2022

Abstract

Background
Since the association of a chromosomal risk haplotype harboring dipeptidyl peptidase-like protein-6 (DPP6) to familial idiopathic ventricular fibrillation (iVF), a growing number of DPP6 missense variants has been reported in patients with ventricular tachyarrhythmias. The mechanisms underlying DPP6 mediated-arrhythmogenesis are not yet fully elucidated. DPP6 is a subunit of the transient outward potassium (Ito) channel complex in Purkinje cells (PC) and ventricular myocytes (VM).

Purpose
Since other Ito-channel subunits (Navβ1, KChIP2, KCNE4 and DPP10) are also known to antagonize INa, we examined whether DPP6 could play a broader role in the inter-regulation of Kv4.3 and Nav1.5 channels. We identified two novel DPP6 variants (p.Arg274His and p.His213Tyr), each segregating in families with QT/QU prolongation. DPP6 p.Arg274His carriers suffered from iVF, ectopic beats from the conduction system, and mitral valve prolapse. Other DPP6 variants (p.Ala751Val identified in this study; p.Gln526His and DPP6-T p.His332Arg published) are associated with Brugada syndrome (BrS). We hypothesized that DPP6 has opposing effects on INa and Ito displaying a reciprocal regulation of these currents.

Methods and results
First, we determined the effect of the DPP6 variants on INa and Ito in transfected CHO cells. Ito density was significantly reduced only when PC subunits were co-expressed with the DPP6 p.Arg274His or p.His213Tyr variants. Indeed, DPP6 modulates Nav1.5 channels in CHO cells by reducing INa Peak and INa Late, whereas DPP6 mutants p.Arg274His or p.His213Tyr resulted in an increase of both components compared to WT. Co-immunoprecipitation experiments in human endocardium confirmed an interaction between DPP6 and Nav1.5 channels. Computing of mutant DPP6-driven Ito-INa changes in a published human PC model led to significant prolongation of the action potential duration, mainly caused by increased INa Late.
On the other hand, the DPP6 p.Gln526His and p.Ala751Val variants, linked to BrS, led to a decreased INa Peak compared to the WT, while there was a tendency towards increased Ito density in both PC and VM molecular setups.
DPP6 (p.Arg274His and p.Ala751Val) transfection experiments in hiPSC cardiomyocytes, expressing endogenous INa and Ito, confirmed the reciprocal results obtained in CHO cells.

Conclusions
DPP6 regulates INa and Ito in a reciprocal manner. The cardiac phenotype of DPP6 variants could encompass a spectrum between two opposite poles: 1) QT/QU prolongation by DPP6 variants causing loss of Ito and gain of INa, like p.Arg274His and p.His213Tyr versus 2) BrS by DPP6 variants leading to gain of Ito and loss of INa, like p.Gln526His and p.Ala751Val.

Funding Acknowledgement
Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): ESC Personal research grant, obtained in 2019
Heterotypic Cx43/Cx45 gap junction channel conductance depends on pulse rate and could rescue from arrhythmogenic activity in cardiac tissue
Authors: Maciunas K , Snipas M , Kraujalis T , Kraujaliene L , Gudaitis L 
Published: October 2022

Abstract

Introduction
Gap junction (GJ) channels, formed of connexin (Cx) proteins, conduit electrical excitation in the heart. It is well established that GJ conductance (gj) depends on transjunctional voltage (Vj), but little is still known about its dynamics during the spread of cardiac excitation.
Transitional tissue of atrioventricular (AV) node expresses Cx43 and Cx45, which could form heterotypic GJs, which are highly sensitive to Vj.

Purpose
Evaluation of heterotypic gj dynamics of Cx43/Cx45 channels during the propagation of excitation in cardiac tissue.

Methods
The CE-4SM model of cardiac tissue, consisting of discrete cells connected through dynamic GJs, was developed by combining Fenton-Karma equations, which define cardiac excitability (CE), and a 4-state model (4SM) of GJ channel gating, which describes the dependence of gj on Vj and its kinetics.
Global optimization methods were applied for 4SM parameter evaluation to fit gj timecourses obtained from electrophysiological recordings.
Experiments were performed using dual-whole-cell patch clamp in Novikoff cells, endogenously expressing Cx43, and Hela cells transfected with Cx45.

Results
We developed a combined cardiac excitability model (CE-4SM), that allowed us to study an interaction between the spread of cardiac excitation and GJ channel voltage. Modeling results shows that during propagation of excitation, the phase difference between each action potential (AP) in adjacent cells, generates two subsequent Vj spikes. First spike causes small decrease of gj, while the second one, a minor increase. These impulses can accumulate into a large overall decay until the impulse rate-dependent steady-state is reached. This phenomenon is caused by variation of delays between APs and consequentially, different durations and amplitudes of Vj spikes developed across GJ channels. Interestingly, such gj decrease was capable of causing drift of spiral wave rotor or termination of fibrillation-like arrhythmia during our modeling experiments.
Also, we performed in-vitro experiments to evaluate 4SM model parameters and validate simulation results that showed gj decay at a high pulse rate, which could occur during reentry-like tachycardia.

Conclusions
Voltage gating of Cx43/Cx45 GJ channels could act as a control circuit, that lowers gj between the transitional cells of AV node at high impulse rate. Presumably, this could help to reduce the conduction or even act as a block of high-rate impulses passing through AV node. Also, such gj decrease could cause a drift of spiral waves and disruption of fibrillation-like processes.

Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): Lithuanian University of Health Sciences, Institute of Cardiology
Association of late-gadolinium enhancement in cardiac magnetic resonance with ventricular arrhythmias and mortality in patients with non-ischemic cardiomyopathy
Authors: Aslam F , Al-Sadawi M , Tao M , Aleem S , Almasry I , Singh A , Rashba E , Fan R 
Published: October 2022

Abstract

Background
Late-gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) is a predictor of adverse events such as cardiovascular mortality, cardiovascular related hospitalization and defibrillation shocks in patients with non-ischemic cardiomyopathy (NICM). The correlation between LGE and ventricular arrhythmia and mortality has not been completely established.

Purpose
This meta-analysis assessed the relationship between LGE in CMR with ventricular arrhythmias: sustained, non-sustained and ICD therapy; and mortality in patients with NICM.

Methods
Databases were queried for studies reporting the association between LGE in CMR in NICM and ventricular arrhythmias and mortality, including Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. The minimal follow up duration was one year.

Results
A total of 46 studies and 10,548 patients (4,610 with LGE vs 5,938 without LGE) were included; mean follow up was 3 years (ranging between 13 to 71 months) and mean left ventricular ejection fraction 33%. LGE in NICM was associated with increased risk of ventricular arrhythmias and sudden cardiac death (odds ratio 4.595, 95% confidence interval 3.54–5.97; P&lt;0.01) and mortality (odds ratio 2.949, 95% confidence interval 2.285–3.806; P&lt;0.01). Heterogeneity is low to moderate: χ2=82.2, df =45 (P=0.001), I2=45% (Figures 1, 2).

Conclusions
Our results suggest that LGE is associated with increased risk of ventricular arrhythmias, sudden cardiac death and mortality in long-term follow up. These results further substantiate the need for larger prospective randomized trials using LGE to decide ICD indication regardless of EF. There are two ongoing trials testing this indication: CMR-ICD and CMR-GUIDE.

Funding Acknowledgement
Type of funding sources: None.