bluuebunny/crossref_metadata_2025_split huggingface dataset:
Left atrial strain analysis in hypertensive heart disease and hypertrophic cardiomyopathy by cardiovascular magnetic resonance feature tracking
Authors: Ferri L , Pica S , Tondi L , Camporeale A , Arosio R , Moroni A , Chow K , Lombardi M 
Published: July 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Increasing evidence suggests that left atrial (LA) deformation is a sensitive marker of diastolic dysfunction in hypertrophic phenotypes. However, there is little data about the impact of hypertension on LA function; furthermore, LA deformation in hypertensive heart disease (HHD) and hypertrophic cardiomyopathy (HCM) has not been compared yet.

Purpose
The aim of this study is to compare atrial dimensions and function, evaluated by cardiovascular magnetic resonance feature tracking (CMR-FT) in patients with HHD, HCM and healthy subjects (HS).

Methods
67 patients (20 HHD, 27 HCM, 20 HS) underwent CMR and were included in the study. Patients were matched for age, sex and BSA; HHD and HCM were also comparable for LV mass index and ejection fraction (EF). CMR-FT atrial strain analysis was performed using Qstrain, Medis software to obtain i) LA conduit function, ii) LA booster pump function), iii) LA reservoir function, iv) LA volumes and EF. Tissue Doppler echocardiography was used to assess diastolic function, including E/e’. LA stiffness was calculated as the ratio between E/e’ and LA reservoir.
Both focal and interstitial myocardial fibrosis were assessed with LGE and extracellular volume (ECV) quantification.

Results
HHD and HCM showed impaired LA reservoir, conduit function and higher LA volumes vs HS (reservoir: 28 ± 11% and 28 ± 13% vs 41 ± 17%; conduit: 13 ± 7% and 13 ± 7% vs 22 ± 11%; LAESV: 76 ± 21 and 87 ± 22 vs 57 ± 19 ml respectively; all p ≤ 0.03).
HHD and HCM were comparable for bi-ventricular morpho-functional parameters and ECV. HHD showed lower E/e’ values (8 ± 2 vs 16 ± 7, p = 0.002) and LA stiffness (0.23 ± 0.3 vs 0.74 ± 0.6, p 0.03), LA dimensions (LA area 13 ± 3 vs 16 ± 3 cm2/m2, p = 0.02 , LAESVi 41 ± 12 vs 48 ± 11 ml/m2, p = 0.05) and LGE extent (1 ± 2% vs 5 ± 5%, p = 0.001) as compared to HCM. Interestingly, HHD revealed a comparable reduced LA reservoir and conduit function (all p = 0.9) vs HCM.
In HHD patients LA reservoir function was correlated with E/e’ (r -0.8, p = 0.02), but not in HCM. Conversely, LA reservoir function was correlated with LV mass index in HCM (r -0.5, p &lt; 0.01).

Conclusions
HHD patients showed a similar and significant impairment of LA function, with lower LA dimensions and E/e’ compared to HCM with similar LV mass index and preserved function.
CMR-FT atrial strain analysis could represent a useful tool for HHD management, able to detect diastolic dysfunction (and/or atrial dysfunction) earlier than traditional markers. Further studies are needed to explore the relationship of LA deformation to heart failure symptoms and atrial fibrillation occurrence and potential changes related to response to therapy.
Prevalence of mitral annulus disjunction and mitral valve prolapse in a multicenter cohort of idiopathic ventricular fibrillation patients
Authors: Groeneveld S , Kirkels FP , Cramer MJ , Evertz R , Haugaa KH , Postema PG , Prakken NHJ , Teske AJ , Velthuis BK , Nijveldt R , Hassink RJ 
Published: July 2021

Abstract

Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation

Background
Idiopathic ventricular fibrillation (IVF) is diagnosed in patients with sudden onset of ventricular fibrillation of which the origin is not identified after extensive evaluations. Recent studies suggest an association between mitral annulus disjunction (MAD), mitral valve prolapse (MVP) and ventricular arrhythmias[1,2]. The prevalence of MAD and MVP in IVF patients in this regard, is not well established.

Purpose
To explore prevalence of MAD and MVP in IVF patients.

Methods
In this retrospective multicenter cohort study, Cardiac Magnetic Resonance images from IVF patients (i.e., negative for ischemia, cardiomyopathy and channelopathies) and matched control subjects were analyzed for MAD (≥2mm) and MVP (&gt;2mm).

Results
In total, 71 IVF patients (mean age 39, 59% male) and 71 controls (mean age 41, 58% male) were included. MAD in the inferolateral wall was more prevalent in IVF patients versus healthy controls (6 [10%] vs. 1 [1%], p = 0.035). MVP was only seen in IVF patients and not in controls (4 [7%] vs. 0 [0%], p = 0.037). MVP was observed both in IVF patients with (n = 3) and without (n = 1) MAD. Patients with MAD did not show papillary muscle fibrosis. Four (67%) patients with MAD showed frequent ventricular ectopy from the basal myocardial region.

Conclusion
Inferolateral MAD and MVP were significantly more prevalent in IVF patients compared to healthy controls (figure). This is in line with previous studies suggesting a correlation between mitral valve disease and IVF. Our findings support further exploration of the pathophysiological mechanisms underlying a subset of IVF that associates with MAD and MVP.
Bicuspid aortic valve fusion length correlates with maximum aortic diameter and heamodynamic abnormalities: a 4D flow CMR study
Authors: Guala A , Teixido-Tura G , Dux-Santoy L , Ruiz-Munoz A , Valente F , Galian L , Gutierrez L , Gonzalez-Alujas T , Johnson K , Wieben O , Sao-Aviles A , Ferreira-Gonzalez I , Evangelista A , Rodriguez-Palomares J 
Published: July 2021

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Guala A. received funding from the Spanish Ministry of Science, Innovation and Universities.

Background
Bicuspid aortic valve (BAV), a congenital heart defect, is associated with ascending aorta dilation, possibly via alteration of aortic blood flow [1]. In BAV abnormal flow condition have been associated with aortic extracellular matrix dysregulation and elastic fiber degeneration [2]. Current morphological classification of BAV patients with aortic valve with a single fusion between two adjacent leaflets does not allow for risk stratification.

Purpose
This research work tested whether the extent of fusion between leaflets is related to AAo diameter and flow alterations.

Methods
Ninety BAV patients free from moderate and severe aortic valve disease and with no previous aortic or aortic valve surgery or replacement were prospectively enrolled. A comprehensive magnetic resonance protocol comprised a stack of double-oblique 2D balanced steady-state free-precession (bSSFP) cine CMR of the aortic valve, which was used to measure the length of the fusion between leaflets, a cine CMR at the level of the pulmonary bifurcation to assess aortic diameter and 4D flow MRI sequence to assess flow characteristics and regional stiffness [3]. Jet angle and flow radial displacement, quantifying the extent of flow eccentricity, and systolic flow reversal ratio (SFRR), assessing the relative amount of backward flow during systole, were computed at 8 equidistant planes in the ascending aorta and 4 equidistant planes in the aortic arch [4]. A two-tailed p-value &lt; 0.05 was considered statistically significant.

Results
The length of leaflet fusion varied widely (median 7.7 mm, inter-quartile range [5.5; 10.2]), Table 1). In bivariate analysis, fusion length was also associated to ascending aortic diameter (R = 0.391, p &lt; 0.001), age (R = 0.313, p = 0.005) and body surface area (R = 0.396, p &lt; 0.001). It was also positively related to flow abnormalities: like displacement in the proximal and distal ascending aorta, jet angle in the mid ascending aorta, and SFRR in the ascending aorta and the aortic arch (see Figure 1). The association between fusion length and ascending aorta diameter persisted in multivariate analysis after correction for age (p = 0.006).

Conclusions
Bicuspid aortic valve fusion extent varies greatly and it is associated with aortic diameter, possibly through flow alterations. Prospective longitudinal studies are needed to establish whether fusion length may allow for risk stratification in bicuspid aortic valve patients.
Prognostic role of cardiac magnetic resonance in left ventricular noncompaction
Authors: Casas G , Limeres J , Barriales-Villa R , Garcia-Pavia P , Zorio E , Gimeno-Blanes JR , Palomino-Doza J , Garcia-Pinilla JM , Bayes-Genis A , Ripoll-Vera T , Jimenez-Jaimez J , Villacorta E , Evangelista A , Ferreira-Gonzales I , Rodriguez-Palomares JF 
Published: July 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Left ventricular noncompaction (LVNC) is a heterogeneous entity with a wide phenotypic expression. Risk factors have not been well established and prognostic stratification remains challenging.

Purpose
Describe prognostic role of CMR on long term outcomes of LVNC patients.

Methods

Retrospective multicentric longitudinal cohort study of consecutive patients fulfilling imaging diagnostic criteria for LVNC (Jenni echo criteria and Petersen and Jacquier CMR criteria). Demographic, ECG, genetic, family and treatment variables were recorded. Baseline CMR was used for the analysis. LV ejection fraction (LVEF) was categorized according to heart failure (HF) guidelines and late gadolinium enhancement (LGE) was visually assessed in a binary way. End points were HF, ventricular arrhythmias (VA), systemic embolisms (SE) and all-cause death. Major adverse cardiovascular events (MACE) were the combination of the four previous end points. In patients with initially preserved LVEF (≥ 50%), LV adverse remodelling (LVAR) was defined as an LVEF &lt; 50% and/or absolute decrease of ≥10% in LVEF at last follow-up.

Results
585 patients from 12 referral centres were included from 2000 to 2018. Age at diagnosis was 45 ± 20 years, 334 (57%) were male, baseline LVEF was 48 ± 17% and 18% presented LGE. During a median follow-up of 5.1 years (IQR 2.3-8.1), 110 (19%) patients presented HF, 87 (15%) VA, 18 (3%) SE and 34 (6%) died. MACE occurred in 223 (38%) patients.
LVEF was independently associated with HF, VA, SE and MACE: HR were 1.08, 1.02, 1.04 and 1.02 respectively (all p &lt; 0.05). LGE was more frequent in patients with reduced LVEF (39 Vs 53%, p &lt; 0.001) and was associated with higher HF and VA risk in patients with an LVEF &gt; 35% (HR 2.69 and 2.48 respectively, p &lt; 0.05) (Figure 1). No MACE (0%) occurred during long-term follow-up in patients with preserved LVEF, no LGE as well as no ECG abnormalities and no family aggregation.
305 (52%) patients presented with initially preserved LVEF, and 230 (75%) of those had LVEF available at last follow-up. LVAR occurred in 50 (22%) patients: 22 (10%) had an LVEF &lt; 50% and 41 (18%) an absolute ≥ 10% decrease in LVEF. LGE was independently associated with LVAR (HR 3.51, p = 0.045) (Figure 2).

Conclusions
Cardiac magnetic resonance has an important prognostic role in LVNC. LVEF is the most powerful predictor of events. Myocardial fibrosis is associated with worse outcomes in patients without severe systolic dysfunction, as well as with left ventricular adverse remodelling in those with initially preserved LVEF. Besides, CMR may identify a low-risk subgroup of LVNC patients. Therefore, CMR should be used in risk stratification in LVNC.
No differences in native T1 of the renal cortex between Fabry patients and healthy volunteers in clinically acquired native T1 maps by cardiovascular magnetic resonance
Authors: Kjellberg F , Sorensson P , Sigfridsson A , Ugander M , Oscarson M , Nickander J 
Published: July 2021

Abstract

Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Karolinska Institutet Swedish Heart and Lung foundation
Introduction
Fabry disease (FD) is a lysosomal disease that causes accumulation of sphingolipids, which untreated may leadto hypertrophic cardiomyopathyand renal failure. Cardiovascular magnetic resonance imaging (CMR) can detect sphingolipid accumulationin the heart, using native T1 mapping. The kidneys are often visible in clinically acquired native T1 maps, however it is currently unknown if clinically acquired native T1 maps of the heart also can be used to detect sphingolipid accumulation in the kidneysin FD patients.
Purpose
To evaluate if clinically acquired native T1 maps using CMR can be used to detect sphingolipid accumulation in the kidneysin FD patients.
Methods
FD patients (n = 18, 41 ± 10 years, 44 % male) and healthy volunteers (n = 41, 26 ± 5 years, 49 % male) were retrospectively enrolled. Native T1 maps were acquired with a 1.5 T scanner (Magnetom Aera, Siemens Healthineers, Erlangen, Germany) usinga modified look locker inversion recovery (MOLLI) sequence with a 5s(3s)3s sampling scheme (Siemens WIP 1041). The native T1 maps were analysed using Segment (Medviso AB, Lund, Sweden). Native T1 values were measured by manually delineating regions of interest (ROI), conservatively placed with a minimum gap of 1 pixel between adjacent structures, in the renal cortex, renal medulla, myocardium, spleen, blood, and liver. Renal cortex ROIs were delineated in all slices where the renal cortex was visible and averaged across all slices. Renal medulla, spleen, and liver ROIs were drawn in the slice where most parenchyma was visible. Endo- and epicardial borders were delineated in all slices of the myocardium and averaged across all slices. Blood ROIs were placed in the midventricular slice, Figure 1.
Results
There were no differences in native T1 values between the patients and the healthy volunteers in the renal cortex (1034 ± 88 vs 1038 ± 51 ms, p = 0.89), blood (1632 ± 123 vs 1600 ± 104 ms, p = 0.94), spleen (1143 ± 45 vs 1134 ± 77 ms, p = 0.64) or liver (569 ± 49 vs 576 ± 45 ms, p = 0.57), and did not change when analysed with regards to sex, Figure 2. Native T1-values were lower in the myocardium of the patients compared to the healthy volunteers (937 ± 53 vs 1019 ± 35 ms, p = 0.01), and higher in the renal medulla (1635 ± 144 vs 1523 ± 70 ms, p = 0.01).
Conclusions
Compared to healthy volunteers, patients with FD and myocardial involvement have no differences in native T1 of the renal cortex. FD patients have higher native T1 in the renal medulla, which cannot be explained by differences in blood native T1. The findings suggest that clinically acquired native T1-maps cannot be used to detect sphingolipid accumulation in the renal cortex in FD patients.
Chromosome-scale assembly of wild barley accession “OUH602”
Authors: Sato Kazuhiro , Mascher Martin , Himmelbach Axel , Haberer Georg , Spannagl Manuel , Stein Nils 
Published: July 2021

AbstractBarley (Hordeum vulgare) was domesticated from its wild ancestral form ca. 10,000 years ago in the Fertile Crescent and is widely cultivated throughout the world, except for in tropical areas. The genome size of both cultivated barley and its conspecific wild ancestor is approximately 5 Gb. High-quality chromosome-level assemblies of 19 cultivated and one wild barley genotype were recently established by pan-genome analysis. Here, we release another equivalent short-read assembly of the wild barley accession “OUH602.” A series of genetic and genomic resources were developed for this genotype in prior studies. Our assembly contains more than 4.4 Gb of sequence, with a scaffold N50 value of over 10 Mb. The haplotype shows high collinearity with the most recently updated barley reference genome, “Morex” V3, with some inversions. Gene projections based on “Morex” gene models revealed 46,807 protein-coding sequences and 43,375 protein-coding genes. Alignments to publicly available sequences of bacterial artificial chromosome (BAC) clones of “OUH602” confirm the high accuracy of the assembly. Since more loci of interest have been identified in “OUH602,” the release of this assembly, with detailed genomic information, should accelerate gene identification and the utilization of this key wild barley accession.
Genome-Wide Detection of Structural Variations Reveals New Regions Associated with Domestication in Small Ruminants
Authors: Cumer Tristan , Boyer Frédéric , Pompanon François 
Published: July 2021

AbstractDuring domestication processes, changes in selective pressures induce multiple phenotypical, physiological, and behavioral changes in target species. The rise of next-generation sequencing has provided a chance to study the genetics bases of these changes, most of the time based on single nucleotide polymorphisms (SNPs). However, several studies have highlighted the impact of structural variations (SVs) on individual fitness, particularly in domestic species. We aimed at unraveling the role of SVs during the domestication and later improvement of small ruminants by analyzing whole-genome sequences of 40 domestic sheep and 11 of their close wild relatives (Ovis orientalis), and 40 goats and 18 of their close wild relatives (Capra aegagrus). Using a combination of detection tools, we called 45,796 SVs in Ovis and 15,047 SVs in Capra genomes, including insertions, deletions, inversions, copy number variations, and chromosomal translocations. Most of these SVs were previously unreported in small ruminants. 69 and 45 SVs in sheep and goats, respectively, were in genomic regions with neighboring SNPs highly differentiated between wilds and domestics (i.e., putatively related to domestication). Among them, 25 and 20 SVs were close to or overlapping with genes related to physiological and morpho-anatomical traits linked with productivity (e.g., size, meat or milk quality, wool color), reproduction, or immunity. Finally, several of the SVs differentiated between wilds and domestics would not have been detected by screening only the differentiation of SNPs surrounding them, highlighting the complementarity of SVs and SNPs based approaches to detect signatures of selection.
Ensemble epistasis: thermodynamic origins of nonadditivity between mutations
Authors: Morrison Anneliese J , Wonderlick Daria R , Harms Michael J 
Published: July 2021

Abstract
Epistasis—when mutations combine nonadditively—is a profoundly important aspect of biology. It is often difficult to understand its mechanistic origins. Here, we show that epistasis can arise from the thermodynamic ensemble, or the set of interchanging conformations a protein adopts. Ensemble epistasis occurs because mutations can have different effects on different conformations of the same protein, leading to nonadditive effects on its average, observable properties. Using a simple analytical model, we found that ensemble epistasis arises when two conditions are met: (1) a protein populates at least three conformations and (2) mutations have differential effects on at least two conformations. To explore the relative magnitude of ensemble epistasis, we performed a virtual deep-mutational scan of the allosteric Ca2+ signaling protein S100A4. We found that 47% of mutation pairs exhibited ensemble epistasis with a magnitude on the order of thermal fluctuations. We observed many forms of epistasis: magnitude, sign, and reciprocal sign epistasis. The same mutation pair could even exhibit different forms of epistasis under different environmental conditions. The ubiquity of thermodynamic ensembles in biology and the pervasiveness of ensemble epistasis in our dataset suggests that it may be a common mechanism of epistasis in proteins and other macromolecules.
The Roles of General and Domain-Specific Perceived Stress in Healthy Aging
Authors: Luo Jing , Zhang Bo , Willroth Emily C , Mroczek Daniel K , Roberts Brent W 
Published: July 2021

Abstract

Objectives
Theoretical and empirical evidence suggests the existence of a general perceived stress factor overarching different life domains. The present study investigated the general perceived stress relative to domain-specific perceived stress as predictors of 26 diverse health outcomes, including mental and physical health, health behaviors, cognitive functioning, and physiological indicators of health.

Method
A bifactor exploratory structural equational modeling approach was adopted in 2 aging samples from the Health and Retirement Study (N = 8,325 in Sample 1 and N = 7,408 in Sample 2).

Results
Across the 2 samples, perceived stress was well represented by a bifactor structure where there was a robust general perceived stress factor representing a general propensity towards stress perception. Meanwhile, after controlling for the general perceived stress factor, specific factors that represent perceived stress in different life domains were still clearly present. Results also suggested age, sex, race, education, personality traits, and past and recent stressor exposure as possible factors underlying individual differences in the general perceived stress factor. The general perceived stress factor was the most robust predictor of the majority of health outcomes, as well as changes in mental health outcomes. The specific factor of perceived neighborhood stress demonstrated incremental predictive effects across different types of health outcomes.

Discussion
The current study provides strong evidence for the existence of a general perceived stress factor that captures variance shared among stress across life domains, and the general perceived stress factor demonstrated substantial prospective predictive effects on diverse health outcomes in older adulthood.
Large-scale balances and asymptotic scaling behaviour in spherical dynamos
Authors: Calkins Michael A , Orvedahl Ryan J , Featherstone Nicholas A 
Published: July 2021

SUMMARY
The large-scale dynamics of convection-driven dynamos in a spherical shell, as relevant to the geodynamo, is analysed with numerical simulation data and asymptotic theory. An attempt is made to determine the asymptotic size (with the small parameter being the Ekman number, Ek) of the forces, and the associated velocity and magnetic fields. In agreement with previous work, the leading order mean force balance is shown to be thermal wind (Coriolis, pressure gradient and buoyancy) in the meridional plane and Coriolis–Lorentz in the zonal direction. The Lorentz force is observed to be weaker than the mean buoyancy force across a range of Ek and thermal forcing; the relative difference in these forces appears to be O(Ek1/6) within the parameter space investigated. We find that the thermal wind balance requires that the mean zonal velocity scales as O(Ek−1/3), whereas the meridional circulation is asymptotically smaller by a factor of O(Ek1/6). The mean temperature equation shows a balance between thermal diffusion and the divergence of the convective heat flux, indicating the presence of a mean temperature length scale of size O(Ek1/6). Neither the mean nor the fluctuating magnetic field show a strong dependence on the Ekman number, though the simulation data shows evidence of a mean magnetic field length scale of size O(Ek1/6). A consequence of the asymptotic ordering of the forces is that Taylor’s constraint is satisfied to accuracy O(Ek1/6), despite the absence of a leading-order magnetostrophic balance. Further consequences of the force balance are discussed with respect to the large-scale flows thought to be important for the geodynamo.