bluuebunny/crossref_metadata_2025 huggingface dataset:
Flocking in a two-agent Cucker-Smale model with large delay
Authors: Cheng Jianfei , Li Zhuchun , Wu Jianhong
Published: February 2021

Delay in feedback is inevitable in a multi-agent system due to time lags in information processing for self-organization. The well-known Cucker-Smale model incorporated with this information processing delay has been recently studied, and it was shown (at least for a two-agent system) that as long as the delay is below a threshold value, the system exhibits the flocking behavior where the agents ultimately reach the same velocity. Numerical studies however suggest that the threshold value established for the delay is not optimal, and the Cucke-Smale system remains to have the flocking property for large delay. Here, we rigorously prove that flocking behavior emerges for a large information processing delay, and we establish the relationship between the admissible size of time delay and the system’s parameters and initial data.
Snipe: highly sensitive pathogen detection from metagenomic sequencing data
Authors: Huang Lihong , Hong Bin , Yang Wenxian , Wang Liansheng , Yu Rongshan
Published: February 2021

Metagenomics data provide rich information for the detection of foodborne pathogens from food and environmental samples that are mixed with complex background bacteria strains. While pathogen detection from metagenomic sequencing data has become an activity of increasing interest, shotgun sequencing of uncultured food samples typically produces data that contain reads from many different organisms, making accurate strain typing a challenging task. Particularly, as many pathogens may contain a common set of genes that are highly similar to those from normal bacteria in food samples, traditional strain-level abundance profiling approaches do not perform well at detecting pathogens of very low abundance levels. To overcome this limitation, we propose an abundance correction method based on species-specific genomic regions to achieve high sensitivity and high specificity in target pathogen detection at low abundance.
Morphometrical Brain Markers of Sex Difference
Authors: Brennan Daniel , Wu Tingting , Fan Jin
Published: February 2021

Many major neuropsychiatric pathologies, some of which appear in adolescence, show differentiated prevalence, onset, and symptomatology across the biological sexes. Therefore, mapping differences in brain structure between males and females during this critical developmental period may provide information about the neural mechanisms underlying the dimorphism of these pathologies. Utilizing a large dataset collected through the Adolescent Brain Cognitive Development study, we investigated the differences of adolescent (9–10 years old) male and female brains (n = 8325) by using a linear Support-Vector Machine Classifier to predict sex based on morphometry and image intensity values of structural brain imaging data. The classifier correctly classified the sex of 86% individuals with the insula, the precentral and postcentral gyri, and the pericallosal sulcus as the most discernable features. These results demonstrate the existence of complex, yet robustly measurable morphometrical brain markers of sex difference.
Provably Secure Online/Offline Identity-Based Signature Scheme Based on SM9
Authors: Lai Jianchang , Huang Xinyi , He Debiao , Wu Wei
Published: February 2021

SM9 is a Chinese cryptography standard, which includes a set of identity-based cryptographic schemes over pairings. SM9 identity-based signature scheme (SM9-IBS) was standardized by ISO/IEC and has been widely used in many real-world applications such as blockchain. Nevertheless, the signing algorithm of SM9-IBS suffers from several heavy calculations (e.g. pairings, scalar multiplications in groups), which might be a bottleneck for lightweight devices such as sensors. In this paper, we modify the SM9-IBS scheme slightly to support fast signing. In order to achieve this, we make the use of online/offline methodology and propose a new online/offline IBS scheme based on SM9. The proposed scheme is proved to be EUF-sID-CMA secure and is about 99% faster than SM9-IBS in terms of signature generation. Precisely, the time cost of online signing is <1 ms. Our scheme is appropriate for the Internet of Things. The theoretical analysis and demonstration show that the proposed scheme is comparable to existing efficient online/offline IBS schemes.
Smart ultrasound device for real-time myocardial stiffness quantification of the human heart
Authors: Pedreira O , Papadacci C , Chatelin S , Correia M , Tanter M , Goudot G , Messas E , Pernot M
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): ERC

Introduction

Myocardial stiffness (MS) is crucial to understand cardiac biomechanics and evaluate cardiac function. We recently demonstrated that shear wave imaging using acoustic radiation force can provide quantitative end-diastolic MS in human patients [1] . However, the dependence of shear wave velocity with myofiber orientation remained a limitation and required to perform Shear Wave Velocity (SWV) estimations from different probe orientations which is challenging in clinical practice. We propose a new approach to provide real-time quantitative assessment of MS without dependence of the probe orientation based on a dedicated smart ultrasound (US) device.

Methods

A new US probe was designed and manufactured to generate acoustic radiation force along the central axis and track the SWV simultaneously along three different orientations to obtain an elliptic profile of SWS. The probe was connected to dedicated electronics and software to provide real-time end-diastolic MS with ECG gating. Validation was performed on 4 in-vitro calibrated phantoms (0.92 – 1.49 – 2.58 – 3.49 m/s) and on ex vivo porcine hearts. MS along and across the fibers were compared to the values measured by conventional shear wave imaging with a linear probe mounted on a rotation motor (angular step of 10°) (Aixplorer, Supersonic imaging). Finally, the in vivo feasibility and reproducibility of measuring MS of the antero-septal wall and of the right ventricular (RV) wall was assessed transthoracically on four human volunteer .

Results

In vitro results on phantoms showed a good agreement with calibrated value (r2 = 0.98, std = 4.8%). Elliptic profiles on ex-vivo porcine heart showed good agreement with Aixplorer measurements acquired at different angles, with a relative difference along the long axis (LA) of: Δ=7.0%, Δ=7.1%, Δ=9% respectively for left ventricle (LV), right ventricle (RV) and septum. Finally, myocardial SWV assessment in human volunteers was obtained successfully on the RV and on the septum in late diastole. The mean MS was 1.79+/- 0.15 m/s along the fiber direction, the  fractional anisotropy (FA) was 0.25 +/- 0.06 on septal wall  in good agreement with previous results [1] and 1.06 +/- 0.11 m/s along fibers orientation and a FA of 0.27 +/- 0.08 on RV.  Finally the beat to beat reproducibility of MS measurement was estimated to be 8.22%.

Conclusion

The new smart US device allowed non-invasive quantification of anisotropic myocardial tissues in real time. Results showed the accuracy of the methods. This approach could offer a new clinical tool for the evaluation of the myocardium in cardiomyopathies and in heart failure patients.

Abstract Figure. SWV on myocardium human volonteer
Alterations in cardiac function in women with severe preeclampsia: return to normal in one year after delivery?
Authors: Ambrozic J , Lucovnik M , Cvijic M
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction. In peri-partum period women with preeclampsia have demonstrated signs of subtle left ventricular (LV) dysfunction. However, there is still controversy if these changes persist or improve late after delivery.

Purpose. To evaluate LV dimensions and function in severe preeclamptic women and healthy controls immediately post-delivery and 1 year postpartum.

Methods. The study population comprised 24 women with severe preeclampsia and 15 healthy term controls. All women underwent standard and speckle-tracking echocardiography to assess myocardial function and deformation parameters 1 day after delivery and 1 year postpartum. To examine the impact of preload and afterload on myocardial function LV end-diastolic volume and systolic blood pressure were used accordingly.

Results. On day 1 post-delivery women with severe preeclampsia were exposed to increased afterload with significantly higher systolic blood pressure compared to controls (147 [136-157] in preeclamptic vs. 112 [102-118] mmHg in control group, p < 0.001). Similarly, preeclamptic women had also higher preload demonstrated with larger LV end-diastolic volume (114 [100-128] vs. 95 [92-102] ml, p = 0.003) and left atrial volume index (36 [33-38] vs. 32 [29-36] ml/m2, p = 0.02) than control group. Among other geometric parameters difference in LV mass index was observed between groups (preeclamptic group: (81 [70-96] vs. control group: 66 [61-74] g/m2, p = 0.01).

Global systolic parameters (LV ejection fraction and global longitudinal strain) did not differ between groups; however, peak systolic myocardial velocity (s’) was significantly lower in preeclamptic compared to control group (7.6 [6.5-8.1] vs. 8.0 [7.5-8.9] cm/s, p = 0.02) immediately post-delivery. Diastolic function differed between groups with significantly higher E/e’ ratio in preeclamptic women than controls (8.7 [7.6-10.0] vs. 6.9 [6.4-7.8] p = 0.01) one day post-delivery.

One year after delivery both groups had normal and similar arterial blood pressure and there were no differences in geometric, systolic and diastolic function parameters between groups (Figure A-D). 

Conclusions. Our results showed that women with severe preeclampsia had subtle cardiac dysfunction immediately post-delivery compared to healthy controls and recovered completely in one year after delivery. Subtle cardiac dysfunction in preeclampsia immediately post-delivery seemed to be related or unmasked by pronounced changes in loading conditions, which resolved in mid-term postpartum period. Long-term follow-up with larger study population is needed to identify subgroup of women who have persistent subclinical cardiac alterations and experience cardiovascular events later in life.

Abstract Figure
Rest NT-proBNP but not MR-proANP predicts positive diastolic stress echocardiography test result in patients with preserved left ventricle ejection fraction and heart failure symptoms
Authors: Kubicius A , Balys M , Gasior Z , Haberka M
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Medical University of Silesia

Introduction

Diastolic dysfunction and heart failure (HF) with preserved ejection fraction are diagnostic challenges in rest transthoracic echocardiography (TTE) and clinical practice. The aim of our study was to evaluate the clinical value of diastolic stress echocardiography (DSE) and its corelation with NT-proBNP and MR-proANP testing in patients with preserved left ventricle ejection fraction (LVEF) and HF symptoms. Methods: All the consecutive patients with HF symptoms, preserved LVEF and suspected diastolic dysfunction were examined with DSE with the protocol according to the EACVI 2016 recommendations. Patients with cardiomyopahties, significant valve defects or extracardiac diseases causing similar symptoms were excluded. The assessment of diastolic function was obtained at rest transthoracic echocardiography (TTE) and at peak exertion in DSE: left atrium volume index (LAVI), average E/e’ >14, peak tricuspid regurgitation velocity >2,8 m/s, septal e’ velocity <7 cm/s or lateral e’< 10cm/s (>50% positive – diastolic dysfunction). Moreover, blood samples for NT-proBNP and MR-proANP were taken just before and 30 minutes after DSE.

Results

The study group included 80 patients (age: 69 ± 8.3 years; 24% males) with dyspnea (NYHA IIa – 53pts; IIb – 17pts; III – 10pts) and risk factors: hypertension (77pts), diabetes (33pts), known coronary artery disease (8pts) and chronic kidney disease (21pts). The rest TTE showed preserved systolic function (LVEF 61.6 ± 8.8%) and normal or indeterminate diastolic function in all patients. DSE revealed positive result for diastolic dysfunction in 17 patients (21%). The levels of NT-proBNP :267(160-518) vs 310(172-522) (p = 0.46) and MR-proANP: 16,2(7,8-542) vs 14,7(6,1-646) p = 0,38 did not significantly change before and after DSE. The ROC analysis showed that age (AUC = 0.720; p < 0.001), LAVI rest (AUC = 0.722, p < 0.01), E/e’ rest (AUC 0.790;p < 0.001) and baseline NT-proBNP (AUC 0.770; p = 0.002) predicted positive DSE. Other parameters, including BMI, baseline E/A, DT or e’ and MR-proANP were not predictive for DSE result. There was a positive correlation between stress NTproBNP and stress LAVI (r = 0.3;p < 0.05) and stress E/e’ (r = 0.5; p < 0.05)  There wasn’t such correlation between MRproANP and stress LAVI and stress E/e’.

Conclusions

Diastolic stress echocardiography revealed diastolic dysfunction in 21% of study patients and improved the diagnostic value of echocardiography. Rest NT-proBNP but not rest MR-proANP predicted positive DSE.
Risk factors of persistent ventricular arrhythmias after mitral valve repair in Barlow disease patients: six-year follow-up
Authors: Malev E , Omelchenko M , Mitrofanova L , Gordeev M , Bondarenko B , Reeva S , Timofeev E
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

 Improvement in malignant ventricular arrhythmias (VA) has been reported after mitral valve surgery in some mitral valve prolapse patients (MVP) with severe degenerative mitral regurgitation. Mitral annular disjunction, posterior systolic curling, and mitral annular abnormal contractility are associated with arrhythmic MVP and underwent correction during the mitral valve repair. However, mitral valve disease progression and ventricular arrhythmic substrates (left ventricular fibrosis of papillary muscles and basal posterior wall) could be potential substrates for persistent malignant arrhythmias even after surgical correction. 

Our aim was to evaluate the risk factors of persistent VA after mitral valve repair in Barlow’s disease patients in six-year follow-up. 

Methods

 30 consecutive patients (mean age 53.1 ± 9.4, 47% male) who underwent mitral valve repair for severe mitral regurgitation (MR) due to mitral valve prolapse were enrolled in our observational, prospective, single-center study. Resected abnormal segments of the mitral leaflets were examined by experienced pathologists for signs of myxomatous degeneration. Transthoracic echocardiography and 24-hour Holter monitoring were performed pre- and postoperatively annually. PVCs and nonsustained ventricular tachycardia (VT) runs were reviewed. 

Results

 All patients survived the operation. There was only one sudden cardiac death on sixth year of follow-up. During 173 person-years of follow-up 3 patients (10%) had developed recurrent moderate to severe (≥2) MR. The total number of PVCs and non-sustained ventricular tachycardia runs dropped significantly in 1st (p=.04, Wilcoxon matched pairs test) and 2nd (p=.03), years of postoperative follow-up. 

Postoperative incidence of PVCs and VT correlated strongly with postoperative end-diastolic LV diameter (EDD rs=.69; p=.005), moderate negatively with LV ejection fraction (EF rs=-.55; p=.001).  

Advanced myxomatous degeneration assessed by pathologists and MV posterior leaflet’s thickness ≥5 mm after repair assessed by echocardiographer associated with postoperative PVCs and VT (rτ=.58; p=.045 and rs=.62; p=.002, respectively). Recurrent MR also strongly associated with postoperative PVCs and VT (rs=.76; p=.0018). 

In univariate analysis, advanced myxomatous degeneration (p=.008), postoperative end-diastolic LV diameter (p=.001), and low EF (p=.003) were identified as risk factors of persistent PVCs/VT after surgery. 

Conclusions

 Advanced myxomatous degeneration assessed by pathologists or echocardiographer and postoperative left ventricular remodeling are associated with persistent malignant ventricular arrhythmias. Further investigation in larger cohorts to evaluate the association between degenerative mitral valve disease and ventricular arrhythmias is needed.
Long-term outcome after transcatheter mitral annuloplasty for secondary mitral regurgitation
Authors: Lavall D , Bruns J , Stoebe S , Hagendorff A , Laufs U
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

The long-term effects of transcatheter mitral valve annuloplasty (TMVA) for secondary mitral regurgitation is unknown.

Purpose

We studied the clinical outcome and the effects on left ventricular (LV) function and remodeling and on mitral regurgitation (MR) severity after TMVA using the Carillon annuloplasty device.

Methods

We analyzed 33 consecutive patients with symptomatic MR who were treated with TMVA at Leipzig University Hospital between 2012 and 2018. Echocardiography was performed before TMVA and at follow-up. MR severity was quantitatively assessed by regurgitant volume (calculated as LV total stroke volume – LV forward stroke volume) and regurgitant fraction (calculated as regurgitant volume / LV total stroke volume).

Results

Mean age was 80 ± 10 years, 19 patients were women. A Society of Thoracic Surgeons (STS) score of 8.1 ± 7.2% indicated high risk status for mitral valve surgery. In 26 patients, mitral regurgitation resulted from LV remodeling and LV dysfunction, 7 suffered from left atrial dilatation. LV ejection fraction at baseline was 38% (30-49%; median, interquartile range). During a mean follow-up time of 45 ± 20 months, 17 patients died, 2 patients withdraw consent, and 4 patients were lost. Of the remaining patients, 4 were hospitalized for decompensated heart failure, and 2 underwent additional transcatheter edge-to-edge mitral valve repair. At follow-up, NYHA functional class improved from 95% in class III/IV at baseline to 70% in class I/II with no patients in NYHA class IV (p < 0.0001). Mitral regurgitant volume was reduced from 27mL (25-42mL) to 8mL (3-17mL) (p = 0.035) and regurgitant fraction from 43% (32-54%) to 11% (8-24%) (p = 0.020). LV end-diastolic volume index (92mL/m2 (71-107mL/m2) vs. 67mL/m2 (46-101mL/m2), p = 0.084) and end-systolic volumes index (51mL/m2 (44-69mL/m2) vs. 32mL/m2 (20-53mL/m2), p = 0.037) decreased. Thus, total stroke volume remained similar (38mL/m2 (33-43mL/m2) vs. 33mL/m2 (26-44mL/m2), p = 0.695) while LV ejection fraction increased (43% (31-49%) vs. 54% (46-57%), p = 0.032). Forward stroke volume, heart rate and forward cardiac output remained unchanged. Blood pressure was similar at baseline and at follow-up.

Conclusion. Among high risk patients undergoing transcatheter mitral valve annuloplasty for symptomatic secondary MR, mortality was about 50% at 4 years. In the surviving patients, reduced MR severity was associated with fewer heart failure symptoms, reverse LV remodeling and improved LV function.
Regurgitant volume to left ventricular end-diastolic volume ratio: another step to risk stratification in patients with secondary mitral regurgitation?
Authors: Lopes P , Albuquerque F , Freitas P , Horta E , Reis C , Abecasis J , Trabulo M , Ferreira A , Canada M , Ribeiras R , Mendes M , Andrade MJ
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

 Quantitative evaluation of secondary mitral valve regurgitation (MR) remains an important yet challenging step in the evaluation of this entity. Its severity can be underestimated when using the proximal isovelocity surface area (PISA) method, which does not take left ventricular (LV) volume into account. Normalizing mitral regurgitant volume (Rvol) for the LV end-diastolic volume (EDV) might overcome this key limitation. This study aimed to investigate the prognostic implication of Rvol/EDV ratio in patients with secondary MR.

Methods

 Patients with at least mild secondary MR and reduced left ventricular ejection fraction (<50%) under optimal guidelines-directed medical therapy were retrospectively identified at a single-center. The cohort was divided into terciles according to the RVol/EDV ratio. The primary endpoint was all-cause mortality.

Results

 A total of 572 patients (median age 70 years; 76% male) were included. Median LVEF was 35% (IQR 28-40) and LVEDV was 169 ml (IQR 132-215). Median measures of secondary MR were EROA 14 mm2 (IQR 8-22) and RegVol 23 ml (12-34). During a median follow-up of 3.8 years (interquartile range 1.8 to 6.2 years) there were 254 deaths (44%). The unadjusted mortality incidence increases across terciles distribution. Patients at the 2nd and 3rd terciles of the RVol/EDV ratio showed significantly higher mortality when compared to those at the 1st one (baseline reference) (figure 1). After multivariable analysis, terciles of the Rvol/EDV ratio remained independently associated with increased all-cause mortality (considering the 1st tercile as the reference; adjusted HR for the 2nd tercile 1.46 [95% CI 1.05- 2.02]  p = 0.023; adjusted HR for 3rd tercile 1.56 [95% CI 1.09 – 2.22], p = 0.015).

Conclusion

 In patients with secondary MR, Rvol/EDV ratio is independently associated with all-cause mortality. However, the appropriate cut-off to determine any kind of clinical decision remains to be determined.

Abstract Figure.
Does age at aortic coarctation repair have an impact on left ventricle size and function?
Authors: Cardoso Torres S , Resende CX , Diogo PG , Araujo P , Pinto RA , Proenca T , Carvalho JM , Amador AF , Costa C , Calvao J , Ribeiro V , Cruz C , Macedo F
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

Adults with repaired aortic coarctation (CoA) require lifelong follow-up due to late complications, including left ventricular (LV) myocardial dysfunction. Age at the time of CoA repair is an important prognostic factor in these patients (pts).

Purpose

To evaluate LV size, ejection fraction (EF) and global longitudinal strain (GLS) values using 2D speckle tracking echocardiography (STE) in a population of adult pts with repaired CoA and to assess the relationship between these echocardiographic parameters and age at the time of CoA repair.

Methods

Retrospective analysis of adult pts with repaired CoA, followed in a Grown Up Congenital Heart Disease Centre. Pts with hemodynamically significant concomitant cardiac lesions were ruled out. Epidemiologic and clinical data were obtained from clinical records. Transthoracic echocardiograms were reviewed in order to assess GLS using 2DSTE (Echopac Software, GE).

Results

The study population consisted of 63 pts (61.9% male), with a mean age of 35.3 years at the time of the echocardiographic evaluation. The mean age at the time of the CoA repair was 117 months (95% CI 89.8-144.1 months).

Surgical repair was performed in 46 pts (73%): resection with subclavian artery flap aortoplasty (n = 21); patch aortoplasty (n = 15) and head-to-head anastomosis (n = 10). In 10 pts there was no data regarding the type of surgical repair. Seven pts (11.1%) were submitted to percutaneous intervention (6 with aortic stent implantation and 1 with balloon aortic angioplasty).

Mean LVEF was 63.4% (CI 95% 55.6 – 71.2%) and mean LV end-diastolic diameter (LVEDD) was 50mm (CI 95% 43-57mm). Mean GLS was - 17.3 (CI 95% 14.8- 19.8), which is inferior to the mean normal values reported for the software used.

Age at the time of CoA repair had a statistically significant positive linear relationship with LVEDD (r= 0.282; p= 0.026) and a linear negative relationship with both GLS (r= -0,29; p= 0.022) and LVEF (r= -0.33; p= 0.05).

Conclusion

Older age at the time of CoA repair was associated with increased LVEDD and decreased GLS and LVEF. Also, GLS may be an important tool for the identification of subclinical LV dysfunction in adult pts with repaired CoA.
Prognostic implications of myocardial work in patients with reduced left ventricular ejection fraction: a preliminary study
Authors: Strada S , Casas Masnou G , Gonzalez Fernandez V , Lozano Torres J , La Mura L , Cinque A , Pisaniello M , Valente F , Fernandez Galera R , Gutierrez Garcia Moreno L , Galian Gay L , Teixido Tura G , Gonzalez Alujas T , Ferreira Gonzalez I , Rodriguez Palomares JF
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background. Myocardial work (MW) is a new imaging technique to assess left ventricular (LV) systolic function. It incorporates both deformation parameters (global longitudinal strain -GLS-) and loading conditions and gives information on global constructive work (GCW), global wasted work (GWW), global LV myocardial work index (GWI) and global LV myocardial work efﬁciency (GWE).

Purpose. The aim of this study was to describe the prognostic role of MW in predicting major adverse cardiovascular events (MACE) in patients with reduced LV ejection fraction (LVEF), and to compare it with GLS and LVEF.

Methods. We retrospectively included consecutive patients from 2012 to 2019 with dilated LV and LVEF < 50% of any aetiology.  Clinical variables were collected and LVEF, GLS and MW were evaluated from baseline echocardiogram. MACE was defined as heart failure (HF) and/or ventricular arrhythmia (VA) and/or cardiac arrest and/or all cause death. 

Results. 99 patients were included, 26 were women (26.3%), mean age at diagnosis was 57 years (SD 23). Mean LVEF was 32.5% (SD 10.3). Baseline patients characteristics are described in Table 1. During a median follow-up of 25 months (IQR 12), 24 MACE were recorded (24.4%). Patients with MACE had worse MW parameters: significantly lower MWI (805 ± 360 % vs 638 ± 277 %, p = 0.04) and lower GCW (1116 ± 535 mmHg vs 874 ± 458 mmHg, p = 0.05), and a tendency to lower GWE (83 ± 11 % vs 77 ± 16 %, p = 0.084).  Of note, both LVEF (33 ± 10% vs 29 ± 9%, p = 0.123) and GLS (-9.99 ± 3.7% vs -8.8 ± 3.0, p = 0.170) showed a trend but were not significantly associated with outcomes. This might suggest that MW variables are stronger prognostic predictors than traditional imaging parameters.

Conclusions. In patients with reduced LVEF, MW parameters including global  MWI and GCW were associated with major adverse cardiovascular events. Of note, both EF and GLS seem to have less prognostic implications in this cohort when compared with MW. Our results are preliminary and larger studies are needed in order to fully understand the clinical utility of MW beyond traditional parameters.

Baseline patient characteristics GLOBAL EVENTS NO EVENTS p Hypertension, % 41 67 29 0.014 Ischaemic etiology, % 14 20 12 0.448 Creatinine, mean (SD) - mg/dL 0.96 (0.04) 1.11 (0.09) 0.90 (0.04) 0.021 Bblockers, % 98 100 97 0.514 Nitrates, % 4 13 0 0.025 Diuretics, % 65 93 53 0.006 SD standard deviation Abstract Figure. Results
Echocardiographic speckle tracking provides incremental value for left atrial function in patients with paroxysmal atrial fibrillation
Authors: Bastos L , Al-Khalili F , Back M , Manouras A , Engdahl J , Shahgaldi K
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Danderyds Hospital

Background

Atrial fibrillation (AF) is associated with progression of left atrial (LA) structural and functional changes. It is well acknowledged that AF over time promotes LA enlargement. Transthoracic echocardiography (TTE) is important in decision making for further treatment. Initially, new onset of AF such as paroxysmal AF can occur in the absence of LA enlargement. Therefore assessment of LA volume index (LAVI) as follow-up can mislead LA evaluation. LA global longitudinal strain (LA-GLS) is a novel parameter assessed with two-dimensional (2D) speckle tracking (ST). LA-GLS allows quantification of LA myocardial deformation by measuring reservoir function which reflects LA compliance during left ventricular systole.

Purpose

Our aim is to study potential differences in LA myocardial deformation as assessed by LA-GLS in paroxysmal AF patients compared with aged-matched control group.

Methods

A total of 75 paroxysmal AF patients and 99 control aged-matched patients (mean age, 77 ± 0.4) were enrolled from STROKESTOP2 study. Patients with paroxysmal AF were included from a subgroup of newly screened-diagnosed AF. TTE examinations were analyzed retrospectively offline using dedicated software. NT-proBNP ≤ 900 ng/L was an inclusion criteria. Besides conventional echocardiographic parameters, LA-GLS was measured using 2D-ST in biplane during systole.

Results

There was a significant LA-GLS reduction in the paroxysmal AF group compared to the control group (19 ± 6.1 % vs. 28 ± 7.2 %, P < 0.001) with a feasibility of 70 %. In the AF group, 45 patients (60 %) expressed normal LAVI <34 ml/m2. No significant difference was revealed concerning LAVI (P > 0.05) between the groups (AF group with normal LAVI), yet LA-GLS remained significant reduced in the AF group (P < 0.001). No significant difference was shown regarding NT-proBNP levels (P > 0.05) between the AF group 243 (179-420) ng/L and the control group 219 (160-317) ng/L.

Conclusion

LA-GLS allows early detection of LA myocardial deformation dysfunction before LA enlargement in patients with paroxysmal AF. This findig provides incremental information to conventional echocardiographic parameters of LA. Whether early detection of LA dysfunction using LA-GLS can contribute to better risk stratification and cardiac therapy improvement requires to be further investigated.
Role of global longitudinal strain to identify and monitor left ventricular dysfunction over time in Becker muscular dystrophy
Authors: Gegenava T , Velde N , Koeks Z , Spitali P , Niks E , Ajmone Marsan N
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

Myocardial involvement is a frequent manifestation of Becker muscular dystrophy (BMD) representing one of the main causes of death; however, it has been shown that left ventricular (LV) systolic function is not specifically related to the degree of skeletal myopathy and therefore each patient should be screened for myocardial involvement. Advanced echocardiographic measures of LV function, such as global longitudinal strain (GLS), have not been studied in BMD patients and might help in identifying myocardial involvement at an early stage. Aim of this study was therefore to perform a longitudinal assessment of LV function but using LV ejection fraction (EF) and GLS in a relatively large cohort of BMD patients (Fig 1). Methods: A total of 40 BMD patients (39 ± 13 years) were analyzed including standard and advanced echocardiography at the time of their first visit and at 24 months (IQR 23-25) follow-up. A control group consisted of 22 age- and gender-matched healthy subjects. Results: BMD patients showed significantly impaired LV systolic function as compared to controls both by  LVEF (47 ± 11% vs. 61 ± 8%, p < 0.001) and LV GLS (-16% (-17%-12%) vs. -19% (-21%-18%), p < 0.001). However, a total of 32 (80%) BMD patients showed impaired LV GLS (based on a reference value -18%) and only 24 (60%) BMD patients showed reduced LVEF (based on reference value 52%) suggesting at the important role of LV GLS to identify early myocardial involvement. Furthermore at the follow-up assessment (available in n = 29 patients), LV GLS showed significant deterioration in BMD patients (from -15%±3 to -14%±4, p = 0.004), while LVEF and LV volumes did not show significant changes over time. Conclusion: LV GLS is significantly impaired in BMD patients and shows progressive deterioration over time, while LVEF remains unchanged. LV GLS might therefore represents a new tool to improve identification of early myocardial involvement and subclinical changes in these patients.

Abstract Figure. LV systolic function in Becker disease
Segmental and global longitudinal strain differences between children with paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 pandemic and Kawasaki disease
Authors: Piccinelli E , Herberg J , Kang H , Fraisse A , Krupickova S , Altamar IB , Sabatino J , Singh Y , Bautista-Rodriguez C , Di Salvo G
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

 The paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) and Kawasaki disease (KD) have overlapping features. This study aimed to describe the strain segmental analysis among both entities.

Methods

Retrospective review of strain segmental analysis within 4 weeks of presentation of symptoms among children diagnosed with PIMS-TS between April and June 2020 and a historic cohort of typical KD from the Royal Brompton Hospital, London.

Results

We included 33 PIMS-TS patients (23 males, 69.7%) at a mean age of 8 ± 4,9 years old and 45 KD patients (31 males, 68,9%) at a mean age of 5,8 ± 4,5 years old. PIMS-TS patients were older at presentation (p = 0.038). Left ventricle ejection fraction (LVEF) was normal in both groups (63,3% vs 63,5%; p= 0,89), 4/33 PIMS-TS children (12,1%) had coronary arteries abnormalities (CAA), whereas 100% of KD cohort had CAA. Both groups had a normal global longitudinal strain (GLS),but in PIMS-TS it was significantly reduced compared to the KD group (-20% vs -22%; p = 0,008). Basal segments were the most affected in PIMS-TS with significant difference in the basal anterior and anterolateral strain compared to KD (respectively -18,2% vs -23,4%; p < 0,001 and - 16,7% vs -22,7%; p < 0,001). PIMS-TS had a greater anterior, anterolateral and posterior segments involvement with a significant reduction in the anterolateral mid-wall longitudinal strain (-18,3% vs -22%; p = 0,002). Apical segments were less involved, with significant difference only in the septal and inferior apical strain (respectively p = 0.001 and p = 0,032).

Conclusions

 These preliminary data showed that after 4 weeks from the onset of symptoms, all PIMS-TS patients had a normal LVEF but they had a significant reduction in GLS and different segmental involvement compared to KD cohort. We hypothesize that these findings may be related to direct myocardial damage in PIMS-TS rather than caused by coronaries perfusion abnormalities.

Abstract Figure. Bull"s eye
Relationship between sporting discipline and aortic dimensions in middle-aged sportsmen
Authors: Hol ME , Aengevaeren VL , Mosterd A , Eijsvogels TMH , Velthuis BK
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

A previous study reported a high prevalence (21%) of clinically relevant aortic dilatation (≥40 mm) in competitive veteran runners and rowers. It is uncertain whether this also applies to middle-aged sportsmen performing other sporting disciplines.

Purpose

To relate aortic dimensions to sporting disciplines in middle-aged sportsmen.

Methods

Middle-aged sportsmen, ≥45 years of age, underwent coronary CT angiography. Aortic size was measured at the sinus of Valsalva (cusp-cusp) and the ascending aorta (at the height of the pulmonary trunk). Dominant sporting discipline was categorized as running, cycling or other. Analysis of variance was used to compare baseline characteristics and aortic dimensions across sporting disciplines. Multivariable linear regression was used to adjust for baseline characteristics. 

Results

A total of 260 sportsmen (mean age 55.1 ± 6.4 years; 64 runners, 75 cyclists and 121 other sporting disciplines) were included (Table). Clinically relevant aortic dilatation was found in 5.0% (n = 13). Aortic size or presence of aortic dilatation did not differ across sporting disciplines. Ascending aorta and aortic root size were significantly related to age, body surface area, diastolic blood pressure and exercise tolerance, but not sporting disciplines.

Conclusions

We found clinically relevant aortic dilatation in 5% of middle-aged sportsmen. Aortic size was not different between sporting disciplines. Aortic size may be more related to level of exercise performance rather than sporting discipline.

Running (n = 64) Cycling (n = 75) Other (n = 121) p value Participant characteristics Age, yrs 54.6 ± 6.4 56.1 ± 6.8 54.8 ± 6.2 0.30 Systolic BP, mmHg 129 ± 12 128 ± 13 129 ± 12 0.95 Diastolic BP, mmHg 80 ± 8 79 ± 8 80 ± 9 0.32 Body surface area, m2 2.03 ± 0.14 2.02 ± 0.15 2.07 ± 0.15 0.08 Exercise tolerance, Watt 310 ± 42* 329 ± 47 307 ± 48 0.003 Aortic dimensions Ascending aorta maximum diameter, mm 32.5 ± 3.1 33.0 ± 3.8 32.5 ± 3.6 0.64 SoV mean diameter, mm 34.3 ± 2.8 34.1 ± 2.8 33.7 ± 3.2 0.46 SoV, NCC-RCC diameter, mm 34.2 ± 2.9 34.0 ± 2.9 33.7 ± 3.4 0.61 Any aortic diameter ≥40 mm, n (%) 3 (4.7) 2 (2.7) 8 (6.6) 0.46 Values are mean SD or n (%). *significantly different from cycling and other. BP = blood pressure; SoV = sinus of Valsalva; NCC = non-coronary cusp; RCC = right coronary cusp
Self-navigated 3D whole-heart MRA for non-enhanced surveillance of thoracic aortic dilation: a comparison to CTA
Authors: Poskaite P , Pamminger M , Kranewitter C , Kremser C , Reindl M , Reinstadler SJ , Reiter G , Piccini D , Tiller C , Holzknecht M , Klug G , Metzler B , Mayr A
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

The natural history of thoracic aortic aneurysm (TAA) is one of progressive expansion. Asymptomatic patients who do not meet criteria for repair require conservative management including ongoing aneurysm surveillance, mostly carried out by contrast-enhanced computed tomography angiography (CTA).

Purpose

To prospectively compare image quality and reliability of a prototype non-contrast, self-navigated 3D whole-heart magnetic resonance angiography (MRA) with contrast-enhanced computed tomography angiography (CTA) for sizing of thoracic aortic aneurysm (TAA).

Methods

Self-navigated 3D whole-heart 1.5 T MRA was performed in 20 patients (aged 67 ± 8.6 years, 75% male) for sizing of TAA; a subgroup of 18 (90%) patients underwent additional contrast-enhanced CTA on the same day. Subjective image quality was scored according to a 4-point Likert scale and ratings between observers were compared by Cohen’s Kappa statistics. Continuous MRA and CTA measurements were analyzed with regression and Bland-Altman analysis.

Results

Overall subjective image quality as rated by two observers was 1 [interquartile range (IQR) 1-2] for self-navigated MRA and 1.5 [IQR 1-2] for CTA (p = 0.717). For MRA a perfect inter-observer agreement was found for presence of artefacts and subjective image sharpness (κ=1). Subjective signal inhomogeneity correlated highly with objectively quantified inhomogeneity of the blood pool signal (r = 0.78-0.824, all p <0.0001). Maximum diameters of TAA as measured by self-navigated MRA and CTA showed excellent correlation (r = 0.997, p < 0.0001) without significant inter-method bias (bias -0.0278, lower and upper limit of agreement -0.74 and 0.68, p = 0.749). Inter- and intraobserver correlation of aortic aneurysm as measured by MRA was excellent (r = 0.963 and 0.967, respectively) without significant bias (all p ≤ 0.05).

Conclusion

Self-navigated 3D whole-heart MRA enables reliable contrast- and radiation free aortic dilation surveillance without significant difference to standardized CTA while providing predictable acquisition time and by offering excellent image quality.

Abstract Figure.
Low-gradient aortic stenosis in patients with concomitant mitral regurgitation - a subgroup analysis from the German aortic valve registry (GARY)
Authors: Alushi B , Ensminger S , Balaban U , Frerker C , Falk V , Lauten A
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by German Cardiac Society, German Society for Thoracic and Cardiovascular Surgery, and German Heart Foundation. Statistical funding support by the German Center for Cardiovascular Research/Deutsches Zentrum für Herz-Kreislauf Forschung (DZHK).

Background

Patients with severe aortic stenosis (AS) frequently present concomitant mitral regurgitation (MR), which may interfere with echocardiographic measurement of mean pressure gradient (MPG), maximal flow velocity and aortic valve area (AVA).

Purpose

We therefore, aimed to investigate the impact of different grades of MR on parameters of AS severity in a large cohort of all-comer patients with severe AS, prospectively included in the national German Aortic Registry (GARY).

Methods

 All patients undergoing transcatheter or surgical aortic valve replacement for severe AS enrolled in GARY between 2011 and 2017 were considered for this analysis. After excluding cases with mitral stenosis and unknown causes of MR, 119,641 patients were considered for the present study. Based on LVEF, the study population was divided into the following subgroups: group 1 (LVEF < 30%, n = 7545), group 2 (LVEF 30-50%, n = 30,116), and group 3 (LVEF > 50%, n = 81,980). Differences in the values of the mPG were explored in each group and in relation to the decremental values of aortic valve area (AVA).

Results

Overall, 37,489 (31.3%) patients had no MR, 77,890 (65.1%) had MR grade I-II, and 4262 (3.6%) had MR grade III-IV. 

In group 1, 2 and 3, no MR was reported in 1339 (17.7%), 7612 (25.3%) and 28,538 (34.8%) patients respectively. MR grade I-II was more frequently observed (group 1 5621 [74.5%] vs. group 2 20,972 [69.6%] vs. group 3 51,297 [62.6%]), whereas MR grade III-IV was observed less frequently and present only in 585 (7.7%), 1532 (5.1%) and 2145 (2.6%) patients in subgroups 1, 2 and 3, respectively.

The aortic mPG was significantly lower in subgroup 1 compared to 2 and 3 (33.74 ± 14.93 versus 41.4 ± 16.47 and 46 ± 16.19mmHg respectively, p < 0.001). With increasing severity of MR, there was a significant reduction of the aortic mPG in each LVEF subgroup (Figure 1). This pattern was maintained irrespective of the AVA value.

Conclusions

 In patients with severe AS, concomitant MR may potentially affect diagnostic accuracy of echocardiographic AS evaluation. In this first GARY analysis of patients with severe AS and concomitant MR, we observed that increasing MR severity affects transvalvular aortic mPG and results in a low-gradient AS pattern. In contrast, AVA is a robust diagnostic parameter for the diagnosis of true severe AS that maintains its validity independently of LVEF and severity of concomitant MR.

Abstract Figure 1
Mechanical contraction patterns of the systemic right ventricle: a 3D echocardiography study
Authors: Surkova E , Kovacs A , Bispo D , Flick C , Lakatos BK , Tokodi M , Liptai C , Fabian A , Merkely B , Senior R , Gatzoulis M , Li W
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background. In patients with transposition of great arteries (TGA) post atrial switch operation or with congenitally corrected TGA (ccTGA), the morphologically right ventricle (RV) has to adapt to the chronically increased systemic pressure.

Purpose. To investigate the functional adaptation of the systemic RV in patients with TGA post Mustard repair or ccTGA. 

Methods. RV volumes and EF were measured by 3D echocardiography in 33 patients with the systemic RV (21 TGA and 12 ccTGA; 45 ± 13y, 61% male), and in 33 healthy volunteers (44 ± 13y, 61% male). 

The 3D RV model was postprocessed by the ReVISION software and its contraction was decomposed along the longitudinal, radial and anteroposterior directions (Fig.A, Systemic RV in TGA) providing longitudinal, radial and anteroposterior EF (LEF, REF and AEF). Relative contribution of each component was measured as the ratio between LEF, REF and AEF to the global RVEF (LEFi, REFi and AEFi).

Results. Systemic RV was significantly larger with reduced function compared to controls (Tab). 3D RVEF demonstrated stronger correlation with BNP (Rho -0.76, p < 0.0001) compared to other parameters of RV function (free wall strain 0.55, p = 0.0083; FAC -0.47, p = 0.024; S’ -0.39 and TAPSE 0.06, p > 0.05).

While in healthy volunteers, all 3 components of RV systolic function contributed equally to the global RV EF, in patients with TGA the relative contribution of the anteroposterior component was dominant and differed significantly from longitudinal and radial components (AEFi 0.48 ± 0.06 vs LEFi 0.31 ± 0.07 vs REFi 0.36 ± 0.09, p < 0.0001)(Fig. B,C). In patients with ccTGA the longitudinal component was dominant and provided a relative compensation for the reduced anteroposterior and radial components (LEFi 0.47 ± 0.07 vs AEFi 0.34 ± 0.07, p = 0.0002 and vs REFi 0.36 ± 0.09, p = 0.0023)(Fig. B,C). Relative contribution of the radial contraction was significantly reduced in all systemic RV patients.

Conclusions. Systemic RV contraction patterns change significantly with anteroposterior contraction being dominant in patients with TGA post Mustard repair and longitudinal component being dominant in ccTGA.

3DE should be a part of routine assessment of the systemic RV, especially in TGA since no conventional echo parameters take into account anteroposterior RV contraction.

Parameters of RV systolic function Parameter Control group (N = 33) All SRV patients (N = 33) TGA (N = 21) ccTGA (N = 12) 3D EF, % 60 ± 3.8 36 ± 8.6* 34 ± 7.3* 38 ± 10* FAC, % 41.4 ± 3.7 25.9 ± 9.3* 25.1 ± 9.2* 27.1 ± 9.9* TAPSE, mm 24.6 ± 4.2 11.9 ± 3.9* 11.1 ± 2.9* 13.2 ± 5.1* RV free wall strain, % -32.5 ± 4.2 -14.5 ± 3.5* -14.5 ± 2.9* -15.5 ± 3.5* * p < 0.0001 Abstract Figure.
Mitral annulus disjunction is associated with adverse outcome in patients with Marfan syndrome and Loeys-Dietz syndrome
Authors: Chivulescu M , Krohg-Sorensen K , Scheirlynk E , Lindberg B , Dejgaard LA , Lie ØH , Helle-Valle T , Skjolsvik ET , Aabel EW , Hunt TE , Estensen ME , Edvardsen T , Lingaas PS , Haugaa KH
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): South-Eastern Norway Regional Health Authority

Background

Mitral valve prolapse is a common finding in patients with Marfan (MFS) and Loeys-Dietz syndromes (LDS). Mitral annulus disjunction (MAD) is an atrial displacement of the hinge point of the mitral valve that frequently coexists with mitral valve prolapse, but its clinical relevance in connective tissue disorders is unknown.

Purpose

To explore the association between MAD and severity of mitral valve and aortic disease in patients with MFS and LDS.

Methods

We included consecutive MFS patients and LDS patients fulfilling established diagnostic criteria. MAD was identified by echocardiography and defined as the distance from the ventricular myocardium to the hinge point of the posterior mitral leaflet (Figure, panel A). Aortic surgery was defined as emergency surgery for aortic dissection or prophylactic aortic surgery for aortic aneurysm. We recorded the need of mitral valve surgery including mitral valve repair or replacement.

Results

We included 168 patients of whom 103 (61%) had MFS and 65 (39%) had LDS. We identified MAD in 69 (41%) patients. Aortic surgery was performed in 112 (67%) patients (27 dissections and 85 prophylactic interventions). Patients with MAD were younger at the time of aortic surgery than those without MAD (p log rank = 0.02) (Figure, panel B). Patients needing aortic surgery had greater MAD distance (8 [7-10] mm vs. 7 [6-8] mm, p = 0.04). Mitral valve surgery was performed in 12 (7%) patients, more frequently in patients with MAD than in those without (16% vs. 1%, p < 0.001, p log rank < 0.001) (Figure, panel C).

Conclusion

MAD was frequent and detected in 41% of patients with MFS and LDS. MAD was associated with a more severe disease phenotype including aortic surgery at younger age and frequent need for mitral valve surgery. Screening patients with MFS and LDS for MAD may provide prognostic information and may be relevant in planning surgical interventions.

Abstract Figure