bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostic accuracy of 4D flow MRI comparing 2mm3 and 3mm3 spatial resolution
Authors: Cave DGW , Shelley D , Michael H , Garg P , Greenwood JP , Plein S , Olaru MA , Van Der Geest RJ , Bissell MM
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health Research, UK University of Leeds

Background

Cardiac magnetic resonance (CMR) examinations requiring repeated breath-holds are challenging in younger patients. While 4-dimensional phase-contrast (4D flow) CMR does not require breath-holds, acquisition has been lengthy. Therefore to date spatial resolution has been influenced mainly by scan length. With accelerated sequences becoming available, higher spatial resolution is becoming clinically feasible.

Purpose

We therefore evaluated the minimum spatial resolution in 4D flow CMR necessary for accurate clinical assessment.

Methods

Ten healthy volunteers (mean age 24.8 years) underwent cardiac examinations on a 3T scanner using a 4D Flow prototype sequence at 2x2x2mm3 (4DFlow2) and 3x3x3mm3 (4DFlow3) spatial resolution. Net forward flow (FF) and peak velocity (PV) using valve tracking were calculated with commercially available software and kinetic energy (KE) in the left ventricle (LV) was analysed using a research tool. Bland-Altman analysis was used for statistical assessment and is reported as bias ± limits of agreement.

Results

Aortic valve flow metrics were similar in 4DFlow2 (FF 94ml; PV 133cm/s) and 4DFlow3 (FF 95ml; PV 130cm/s), and both showed good agreement with 2D PC MRI (FF 93ml, Bland-Altman:1.6 ± 9.7 and 2.2 ± 13.5, respectively). Similar results were obtained for pulmonary valve flow (FF 138cm/s; Bland-Altman:4.7 ± 15.1 and 8.1 ± 18.2, respectively). Branch pulmonary artery (PA) FF showed good agreement with the main PA FF in 2D and 4DFlow2 (Bland-Altman:1.1 ± 15.9 and 1.1 ± 10.6, respectively), but not in 4DFlow3 (Bland-Altman:1.1 ± 32.5). Global LV KE measured by 4DFlow3 was on average 12% lower compared to 4DFlow2, whereas maximum systolic LV KE was similar in both acquisition methods.

Conclusions

3mm3 spatial resolution appears to be sufficient for clinical evaluation of aortic and pulmonary valves. Smaller vessels such as branch pulmonary arteries require higher resolution for accurate assessment. While no gold standard is available for kinetic energy assessment, our results suggest that some parameters LV energetic assessment is spatial resolution sensitive. Differences in SNR might also contribute to the differing results.

Abstract Figure. Bland-Altman plots for 4D flow MRI
Prognostic value of vasodilator stress perfusion CMR in patients with known myocardial infarction
Authors: Pezel T , Garot P , Kinnel M , Landon V , Hovasse T , Toupin S , Unterseeh T , Morice MC , Champagne S , Louvard Y , Sanguineti F , Garot J
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

Several studies have demonstrated the consistently high prognostic value of stress perfusion cardiovascular magnetic resonance (CMR). This prognostic value in patients with known myocardial infarction (MI) is poorly described. There remains some skepticism about the capacity of stress CMR in predicting the clinical outcome due to the technical challenge during image analysis causes by myocardial scar.

PURPOSE

The aim of our study was to assess the prognostic value of vasodilator stress perfusion CMR in patients with known MI.

METHODS

We prospectively included consecutive patients with known MI referred for vasodilator stress perfusion CMR with dipyridamole. They were followed for the occurrence of major adverse cardiovascular events (MACE) defined as cardiac death or recurrent non-fatal myocardial infarction (MI). Univariable and multivariable Cox regressions for MACE were performed to determine the prognostic value of inducible ischemia or late gadolinium enhancement (LGE) by CMR.

RESULTS

Of 1602 patients with known MI (68 ± 17 years, 78% men), 1556 (97%) completed the CMR protocol, and among those 1401 (90%) completed the follow-up (median follow-up 5.7 (3.9–7.6) years). Reasons for failure to complete CMR included ECG-gating problems (n = 13), intolerance to stress agent (n = 12), renal failure (n = 12), declining participation (n = 4) and claustrophobia (n = 5). Stress CMR was well tolerated without occurrence of death or severe adverse event. Patients without inducible ischemia experienced a substantially lower annual event rate of MACE (3.1%) than those with 1 or 2 segments of ischemia (4.5%), than those with 3 to 5 segments of ischemia (21.5%), than those with 6 or more segments of ischemia (45.7%, for all p < 0.01). Using Kaplan-Meier analysis, the presence of myocardial ischemia identified the occurrence of MACE (hazard ratio HR 3.52; 95% confidence interval CI: 2.67 – 4.65; p < 0.001). In a multivariable stepwise Cox regression including clinical characteristics and CMR indexes, the presence of inducible ischemia was an independent predictor of a higher incidence of MACE (HR 2.84; 95% CI: 2.14 to 3.78; p < 0.001).

CONCLUSION

Stress CMR is technically feasible and has a good discriminative prognostic value to predict the occurrence of MACE in patients with known MI.

Abstract Figure. Kaplan-Meier curves for MACE
Influences on myocardial perfusion in non-obstructive coronary disease: an observational quantitative perfusion mapping study
Authors: Knott K , Seraphim A , Augusto JB , Camaioni C , Kotecha T , Xue H , Joy G , Bhuva AN , Manisty C , Brown LAE , Wong J , Fontana M , Kellman P , Plein S , Moon JC
Published: February 2021

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This study was supported by a Clinical Training Research Fellowship (K. Knott) from the British Heart Foundation and directly and indirectly from the Biomedical Research Centre at University College London Hospitals and Barts Heart Centre.

Background

Cardiovascular magnetic resonance (CMR) with automated inline perfusion mapping permits rapid fully automated non-invasive myocardial blood flow (MBF, ml/g/min). Understanding the microvascular component of MBF would help optimize epicardial coronary artery disease detection and potentially serve as an independent diagnostic / therapeutic target. 

Purpose

To explore MBF influences at stress and rest in patients with unobstructed epicardial coronary arteries.

Methods

242 participants (mean age 56.9 years) from 5 European centers with unobstructed epicardial coronary arteries and no myocardial scar underwent adenosine vasodilator perfusion mapping at stress and rest. The factors influencing MBF were determined using univariate and multivariate linear regression analyses.

Results

Mean rest perfusion was 0.91+/-0.24ml/g/min. Rest perfusion was higher in females (0.97+/-0.22ml/g/min vs 0.83 +/- 0.24ml/g/min) and lower in patients on beta blockers. Mean stress MBF was 2.53+/-0.82ml/g/min. Factors independently associated with reduced stress MBF were increasing age, diabetes, increasing left ventricular mass (LVMi) and the use of beta blockers.  The predicted stress MBF can be obtained from the equation MBF = 2.66–0.015(age-60)–0.013(LVMi-57)-0.405(diabetes)–0.365(beta blocker). This means stress MBF falls 10% over 19 years and that diabetes drops the MBF by the equivalent of being 27 years older. These changes are large: for example, a 70-year-old diabetic would have 30% lower stress MBF than a 35 year-old non-diabetic. 

Conclusions

In the absence of obstructive epicardial coronary disease, stress MBF falls with age, diabetes, increased LV mass and beta-blockers. These data may help develop normal reference ranges, input to other modelling (eg CT FFR), and they advance perfusion mapping as a measure of microvascular function.

Abstract Figure. Summary of the determinants of perfusion
Phantom based quality assurance for long-term stability and inter-scanner compatibility in T1, T2 and T2* measurements
Authors: Peltonen J , Soikkeli M-L , Heikkila S , Kaasalainen T
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

The quantitative measurement of T1, T2 and T2* relaxation parameters is prone to numerous physical variables related to scanner performance and installation environment. These variables include the presence of eddy currents, main magnetic field inhomogeneity and gradient field performance. Thus, it is important to verify that the measured relaxation parameters are inter-scanner compatible and there are no drift in the measured values over time.

Purpose

In this study, we produced a phantom for the relaxation parameter measurements. With the phantom, long-time stability and inter-scanner comparison of parameters were studied with preliminary quality assurance protocol.

Methods

A cylindrical quality assurance phantom with 16 inserts filled with ammonium iron(II) ((NH4)2Fe(SO4)2 · 6H2O) doped gel was produced. The (NH4)2Fe(SO4)2 concentrations were from 0,0119 mmol/g to 0,5498 mmol/g, corresponding to approximate T1 values of 10–1030 ms, T2 values of 16–78 ms and T2* values of 5–61 ms. The phantom was measured quarterly for a one-year period with three scanners from two different vendors to follow the scanner stability and inter-scanner compatibility. The used imaging sequences included T1 MOLLI -based sequence, T2 prep -based sequence, and multi-echo gradient echo sequence for T2* calculation. Simulated ECG signal with 60 beats per minute was used in the scanning to mimic a typical rest heart rate of an adult patient.

Results

The range of variation between scanners from average relaxation coefficient in T1 was -2% to 4% and in T2 and T2* measurements -7% to 5% and -32% to 18%, respectively. In long-term stability test, the range of variation from average relaxation coefficient in T1 was -1% to 2% and in T2 and T2* measurements -1% to 1% and -15% to 16%, respectively.

Conclusion(s)

There were significant differences in the measured T1, T2, and T2* relaxation coefficients in both inter-scanner and long-term stability. However, the detected variations were acceptable compared to the typical physiological uncertainties of the measured parameters but have to be taken into account when the reliability of the study is assessed.

Abstract Figure. Results and phantom image
Self-navigated versus navigator-gated 3D MRI sequence for non-enhanced aortic root measurement in transcatheter aortic valve intervention
Authors: 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

Preprocedural transcatheter aortic valve intervention (TAVI) evaluation requires reliable aortic root measurements for correct valve sizing.

Purpose

To prospectively compare image-quality, reliability and graft sizing of a prototype self-navigated and a navigator-gated non-contrast three dimensional (3D) whole-heart magnetic-resonance-angiography (MRA) sequence with computed-tomography-angiography (CTA) for planning transcatheter-aortic-valve-intervention (TAVI).

Methods

Self- and navigator-gated 1.5T MRA were performed in 27 patients (aged 83 ± 5 years, 41% male) for aortic root sizing and coronary ostia height measurements; 15 (56%) patients underwent additional CTA. Subjective-image quality was graded on a 4-point Likert scale, objective MRA image-quality was assessed by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Continuous MRA and CTA measurements were analyzed with regression and Bland-Altman analysis, valve sizing by kappa statistics.

Results

Median image-quality as rated by two observers was 1.5 [interquartile range (IQR) 1-3] for self-navigated MRA and 1 [IQR 1-2] for navigator-gated MRA (p = 0.059). SNR and CNR were comparable between MRA sequences (p = 0.471 and 0.445, respectively). Acquisition time was shorter for self-navigated MRA compared to navigator-gated MRA (5.5 ± 1 minutes vs, 6.5 ± 2 minutes, p = 0.029).  Inter-observer correlation of aortic root measurements was high to very high for both self- and navigator-gated MRA (r = 0.75 to 0.94 and r = 0.85 to 0.96, respectively, all p < 0.0001). Theoretical prosthetic valve sizing of self-navigated MRA and CTA was equivalent (κ=1). However, in four patients (15%) one coronary ostium each (right coronary artery 3, left main artery 1) was not clearly definable on self-navigated MRA.

Conclusion

Self-navigated MRA enables aortic annulus TAVI measurements without significant difference to navigator-gated MRA at shortened acquisition time. Prosthesis sizing by self-navigated MRA measurements is equivalent to navigator-gated MRA and CTA-based choice.

Abstract Figure.
Clinical significance of Q waves in ischemic cardiomyopathy
Authors: Rodenas Alesina E , Jordan P , Herrador L , Espinet-Coll C , Pizzi N , Aguade-Bruix S , Ferreira-Gonzalez I
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): CIBER-CV

AIMS

The scintigraphic translation of Q waves in patients with ischemic cardiomyopathy and LVEF < 40% has not yet been assessed. The aim of this study was to explore the relationship between Q waves and necrotic tissue and to analyze their impact in prognosis.

METHODS AND RESULTS

A retrospective study enrolling 487 consecutive patients (67,0 [57,4 – 75,4] years), with ischemic cardiomyopathy, LVEF <40% and narrow QRS who underwent stress-rest SPECT was conducted. Patients with Q waves (320 patients [65,7%]) had less comorbidity and ischemia, but more necrosis. Q waves correlated poorly with lack of viability (AUC = 0,63) and were independently associated with the subendocardial extent of the necrosis. After a follow-up of 5,07 years, the primary outcome (cardiovascular death, heart failure hospitalization or myocardial infarction) occurred in 192 (39,4%) patients, without differences between groups in multivariate analysis. After accounting for non-cardiovascular death as a competitive risk, the interaction between >10% of ischemia and revascularization remained in Cox model both in the total cohort (aHR= 0,46 [0,24 – 0,86]), and in patients with Q waves (aHR = 0,27 [0,11–0,69]).

CONCLUSION

Patients with ischemic cardiomyopathy with Q waves have larger subendocardial scarring and more transmural necrosis, although correlation between Q waves and transmural scarring is poor. Revascularization if >10% ischemia is present is associated with a better prognosis. Ischemia burden should be assessed and accordingly treated in these patients, and no differences in management should be made in the presence of Q waves.

Table 1. Cox proportional hazards model Total cohort (N = 471) Patients with Q waves (N = 315) aHR p-value 95% CI aHR p-value 95% CI Age (per year) 1,02 0,007 1,01 - 1,04 n.s. Diabetes mellitus 1,35 0,047 1,00 - 1,81 1,54 0,016 1,09 - 2,20 eGFR < 60 ml/min 1,59 0,005 1,15 - 2,21 1,96 <0,001 1,36 - 2,82 Previous HF hospitalization 1,71 0,002 1,23 - 2,38 1,76 0,007 1,17 - 2,64 Previous PCI 1,32 0,069 0,98 - 1,78 n.s. Previous CABG n.s. 1,77 0,009 1,15 - 2,72 Angina or dyspnea 1,68 0,001 1,24 - 2,28 1,71 0,004 1,19 - 2,46 Indexed TDV (per quartile) 1,16 0,047 1,02 - 1,33 n.s. Revascularization*ischemia > 10% 0,46 0,015 0,24 - 0,86 0,27 0,006 0,11 - 0,69 Cox regression for the primary endpoint (cardiovascular death, heart failure hospitalization or myocardial infarction), accounting for non-cardiovascular death as a competitive risk. Abstract Figure. Survival for the primary endpoint
Coronary, aortic and carotid artery inflammation by 18F-fluorodeoxyglucose positron emission tomography in acute and chronic coronary artery disease
Authors: Nammas W , Uotila S , Teuho J , Pietila M , Airaksinen J , Roivainen A , Bax J , Knuuti J , Saraste A
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) can detect arterial inflammation in individuals with atherosclerosis, but the associations among different vascular territories for 18F-FDG uptake are not known.

Purpose

We explored any possible correlation between arterial inflammation quantified by 18F-FDG PET in the aorta, carotid arteries, and coronary arteries in patients presenting with acute coronary syndrome (ACS), or chronic coronary artery disease (CAD).

Methods

Prospectively, we performed hybrid computed tomography angiography and 18F-FDG PET in 43 patients (26 ACS and 17 chronic CAD) at 6.6 ± 5.7 days following invasive coronary angiography. 18F-FDG PET was performed 90 minutes after injection of 302.2 ± 28.4 MBq 18F-FDG. Arterial 18F-FDG uptake was measured in the thoracic aorta, carotid arteries, and coronary arteries, and expressed as the target-to-background ratio (TBR; the ratio between arterial maximal standardized uptake value normalized to blood pool mean standardized uptake value) in the whole artery, and in the most diseased segment (MDS).

Results

Mean age was 64.9 ± 9.1 years, 90.7% males. The whole artery 18F-FDG uptake was higher in the aorta than in the carotid arteries (median TBR 2.23, interquartile range [0.36] vs. 1.88 [0.42], p < 0.001); whereas uptake in the coronary arteries was lower than in the aorta or carotid arteries (1.13 [0.23], p < 0.001 both). Similarly, 18F-FDG uptake in the aortic MDS was higher than in the carotid MDS (2.75 [0.62] vs. 2.25 [0.63], p < 0.001); whereas 18F-FDG uptake in the coronary MDS was the lowest (1.40 [0.33], p < 0.001 both). These findings were consistent in both ACS and chronic CAD patients. The whole artery 18F-FDG uptake of the aorta and carotid arteries correlated in patients with ACS (r = 0.58, p = 0.002), but not in patients with chronic CAD (r = 0.21, p = 0.3). There was no correlation between the whole artery 18F-FDG uptake in the coronary arteries and either the aorta or carotid arteries in the whole cohort (r=-0.16, p = 0.2, r = 0.01, p = 0.9, respectively), in patients with ACS (r = 0.06, p = 0.7, r=-0.01, p = 0.9, respectively), or in those with chronic CAD (r=-0.4, p = 0.1, r=-0.09, p = 0.7, respectively).

Conclusions

In patients with ACS or chronic CAD, large arteries had higher 18F-FDG uptake than the coronary arteries. The intensity of 18F-FDG uptake in the coronary arteries did not correlate with that in the carotid arteries or the aorta, indicating that disease activity differs between large arteries and coronary arteries.
The prognostic value of B-lines in heart failure with preserved ejection fraction
Authors: Nemeth N , Morvai-Illes B , Szabo I , Gargani L , Varga A , Agoston G
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background

 Heart Failure with Preserved Ejection Fraction (HFpEF) is a growing healthcare burden, and its prevalence is steadily increasing. Despite its common occurrence, HFpEF remained a challenge in every aspect. The evaluation of B-lines with lung ultrasound (LUS) is a promising diagnostic and prognostic tool in this population.

Objectives

The aim of our study was to assess the diagnostic and prognostic performance of B-lines compared with traditional clinical, echocardiographic parameters and natriuretic peptide levels in patients with clinical suspicion of HFpEF.

Methods

78 consecutive patients (70.45 ± 6.75 years, 72% female) with suspected HFpEF were prospectively enrolled. Exclusion criteria were: ejection fraction ≤55%, more than mild mitral and/or aortic valve disease, cardiomyopathy, pulmonary disease, pulmonary arterial hypertension, renal failure and anemia. All patients underwent comprehensive echocardiography, lung ultrasound exam and NT-proBNP measurement during their first appointment. Our endpoint was a composite of acute heart failure (HF),  hospitalization for the worsening HF symptoms and intensification of diuretic therapy. Also, traditional major cardiac adverse events such as death, myocardial infarction, stroke and revascularization were collected.

Results

We detected 11 events during 12 ± 6 months follow up. The number of B-lines showed a good correlation with NT-proBNP levels (p < 0,001, r = 0.693). B-lines were found to have similar performance to NT-proBNP in predicting events (AUC = 0.778 vs. 0.770, respectively). Those who had more than 30 B-lines on LUS had significantly worse event-free survival p = 0.004. Having more than 30 B-lines at baseline was associated with 7 times greater hazard of adverse outcomes.

Conclusions

LUS is a simple, feasible tool to detect pulmonary congestion in patients with HFpEF. In our prospective cohort study, LUS was found to be a useful tool for prognostic stratification.

Abstract Figure. Prognostic value of B-lines
Clinical outcome analysis in patients with COVID 19 using echocardiography and biochemical markers
Authors: Al Barjas M , Lancioni M , Eley A , Catibog J
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND AND PURPOSE

Cardiac involvement in patients with COVID-19 is still unclear. We made a systematic echocardiographic and biochemical assessment of patients admitted with COVID-19 infection to assess correlation with various clinical outcomes.

METHODS

We prospectively assessed 119 consecutive COVID-19 positive in-patients with full echocardiography studies, including left ventricle (LV) systolic function, right ventricle (RV) basal dimension and systolic function using Tricuspid Annular Plane Systolic Excursion (TAPSE) and systolic pulmonary artery pressure (SPAP). We excluded all patients with known left ventricular systolic dysfunction (LVSD) prior to admission. We also recorded laboratory biochemical findings including troponin-T, D-dimer and NT-proBNP levels. We carried out correlation analyses of the echocardiography and the laboratory biochemical findings with various clinical outcomes including mortality, length of stay (LOS), admission to Intensive Care Unit (ICU) and the three month re-admission rates.

RESULTS

119 patients (38% female); age range 35 to 96 years (mean 71, median 73). 37 (31%) patients died during hospital admission.  The mean LOS for surviving patients was 32 days.

20 (17%) patients had significant LSVD (by biplane Simpson method, EF cut off 45%), 31 (26%) patients had RV dilatation, 28 patients (24%) had RV systolic dysfunction by TAPSE and 41 (35%) patients had raised pulmonary artery pressures. There was a weak Pearson’s correlation between mortality and LVSD (0.184, p 0.046), a moderate correlation with RVSD (0.303, p 0.001) and RV dilatation (0.231, p 0.012). Raised troponin-T and NT-proBNP levels correlated moderately with mortality (0.254, p 0.013 and 0.253, p 0.02 respectively). 

D-dimer levels did not correlate with mortality or any of the other clinical outcomes. Raised troponin-T levels had moderate correlation with admission to ICU and LOS (0.210, p 0.043 and 0.267, p 0.01 respectively). SPAP in isolation did not correlate with any of the clinical outcomes. None of the echocardiography or laboratory biochemical variants correlated with re-admission rates.

CONCLUSION

In our cohort of patients with COVID-19 infection there is a weak to moderate mortality correlation with LV function, RV function and RV size. Laboratory biochemical markers especially troponin-T correlated more widely and moderately with clinical outcomes.
Prognostication of the abdominal aortic aneurysm with a novel three-dimensional ultrasonographic analysis system and its comparison with computed tomography
Authors: Younus S , Maqsood H , Awais R , Gulraiz A , Khan MD
Published: February 2021

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Self

Introduction

An abdominal aortic aneurysm is a life-threatening condition and the risk of rupture is higher with the increased maximum diameter (Dmax) and expansion rate. Therefore, AAAs require regular monitoring of Dmax. The most commonly used imaging technique for measuring AAA size is two-dimensional ultrasonography (2-D US), closely followed by computed tomography (CT).

Purpose :

This study sought to evaluate the accuracy of a novel semi-automated 3-D ultrasonography (3-D US) system and its comparison CT as a reference.

Methods :

A total of 66 patients with abdominal aortic aneurysm were prospectively recruited in an outpatient setting. Two-dimensional ultrasonography (2-D US) and 3-D US images were attained with a single-sweep volumetric transducer. Dmax and the vessel area of the Dmax slice were measured with 2-D US, 3-D US, and CT. The vessel, lumen, and thrombus areas of the Dmax slice were also measured using 3-D US and CT.

Results :

It was found that the Dmax values from the 3-D US demonstrate better agreement (R2 = 0.971) with the CT values than with the 2-D US values (R2 = 0.929). Overall, 2-D US underestimated Dmax compared with 3-D US (30.8 ± 13.1mm vs. 34.4 ± 11.6 mm). The vessel, lumen, and thrombus areas all demonstrated better agreement with CT than with 2-D US (R2 = 0.988 vs. 0.961 for the vessel, R2 = 0.879 vs. 0.829 for the lumen, and R2 = 0.963 vs. 0.849 for the thrombus).

Conclusion :

Our study concludes that our novel semi-automated 3-D US analysis system provides more accurate Dmax values and volumetric data as compared to the 2-D US. The application of the semi-automated 3-D US analysis system in an abdominal aorta assessment is easy and accurate.

Abstract Figure. Comparison of AAA on three modalities
Adverse cardiovascular ageing among older women and cardiometabolic ageing
Authors: Ho J , Kovalik J , Gao F , Zhao X , Shuang L , Teo L , Tan R , Ewe S , Wee H , Ching J , Koh W , Zhong L , Koh A
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): National Medical Research Council (NMRC)

Background

Despite longer life expectancies, women may experience reduced ‘health-span’ (period of life spent in good health) due to accumulation of risks over their longer life spans. Metabolic factors present in diet and lifestyle may provide modifiable solutions to tackle burdens of cardiovascular (CV) ageing in women.

Objective

We aim to study gender differences in CV structure and function among community older adults without clinical CV disease, as well as metabolic perturbations in their study samples.

Methods

We examined a prospective cohort study of older adults, obtaining their medical history, serum sampling, echocardiography and cardiac magnetic resonance (CMR) imaging on a single day visit. Echo E/A ratio was computed as a ratio of peak velocity flow in early diastole E (m/s) to peak velocity flow in late diastole by atrial contraction A (m/s) mitral inflow velocities. Longitudinal strain (ε) at any time point (t) in the cardiac cycle from end-diastole (time 0) was calculated as: ε(t)=(L(t)-L0)/L0, obtaining left atrial (LA) reservoir strain (εs), conduit strain (εe) and booster strain (εa) by CMR. Metabolomics profiling was performed by standard mass spectrometry techniques.

Results

Among n = 492 (49.6%, n = 244 women, mean age 73 ± 4 years) participants, women had lower prevalence of hypertension (52% vs 58%, p < 0.0001), smoking (4% vs 35%, p < 0.0001), but higher prevalence of dyslipidemia (52% vs 50%, p = 0.001) compared to men. Women had lower left ventricular mass index (69 vs 71 g/m2, p < 0.0001) compared to men. However, women had more adverse CV function, such as lower E/A ratio (0.78 vs 0.85, p < 0.0001), lower LA booster (εa) (16.5 vs 17.8, p = 0.027) and lower LA reservoir (εs) strain rate (1.5 vs 1.6, p = 0.012), compared to men. Amino acids such as alanine, arginine, aspartate, citrulline, glycine, phenylalanine and valine were similar between gender. However, women had higher levels of tyrosine (76 vs 68 μM, p = 0.015). On multivariate adjustment, apart from age, tyrosine was independently associated with E/A ratio (β=0.002, 95%CI 0.00-0.004, p = 0.044) and εs (β=0.004, 95%CI 0.00-0.009, p = 0.048) among women. 

Conclusion

Utilizing conventional and sensitive CV imaging, women appeared to have more adverse CV functions with ageing. As a branched chain amino acid linked to future risk of CV disease, tyrosine may be linked to adverse CV function. Factors that contribute to these cardiometabolic profiles, such as menopause, diet or lifestyle warrant further research.
Hypertrophic cardiomyopathy with moderate septal thickness and mitral regurgitation: long-term surgical results
Authors: Lapenna Elisabetta , Nisi Teodora , Carino Davide , Bargagna Marta , Ruggeri Stefania , Zancanaro Edoardo , Del Forno Benedetto , Schiavi Davide , Agricola Eustachio , Castiglioni Alessandro , Alfieri Ottavio , De Bonis Michele
Published: February 2021

OBJECTIVES

The aim of this study was to assess the long-term outcomes of different surgical strategies in patients with hypertrophic obstructive cardiomyopathy (HOCM) with septal thickness ≤18 mm and systolic anterior motion (SAM)-related moderate-to-severe mitral regurgitation (MR).

METHODS

Seventy-six HOCM patients with septal thickness 17 [16; 18] mm, resting left ventricle outflow tract gradient 60 [41; 85] mmHg and SAM-related MR ≥2+/4+, underwent septal myectomy alone (54%) or mitral valve (MV) surgery ± myectomy (46%).

RESULTS

No hospital death and no ventricular septal defect occurred. Patients undergoing MV surgery ± myectomy had longer cardiopulmonary bypass and X-clamp times (77 [60–106] vs 51 [44–62] min, P < 0.001 and 56 [45–77] vs 32 [28–41] min, P < 0.001) and higher incidence of low output syndrome (11% vs 0%, P = 0.04). Follow-up was 98.6% complete, median 8 years [3–11]. There were no statistically significant differences in overall survival (P = 0.069) with survival rates at 9 years of 96 ± 4% in the myectomy alone group and 81 ± 8% in the MV surgery ± myectomy one. At 9 years, cumulative incidence function of cardiac death was 12 ± 6% in the MV surgery ± myectomy group vs 0% in the myectomy one, P = 0.06. Multivariable analysis identified age and previous septal alcoholization as predictors of cardiac death (hazard ratio (HR) = 1.1, 95% confidence interval (CI) 1.0–1.1, P = 0.004 and HR = 2.9, 95% CI 1.0–8.3, P = 0.042). The 9-year cumulative incidence function of recurrence of MR ≥2+, with death as competing risk, was 3 ± 2.8% in the MV surgery ± myectomy group vs 25 ± 6.9% in the myectomy one, P = 0.005.

CONCLUSIONS

In HOCM patients with moderate septal thickness and SAM-related MR, as the degree of septal hypertrophy decreases, addressing the abnormalities of the MV apparatus may become necessary to provide a durable resolution of left ventricle outflow tract obstruction and SAM-related MR. However, performing myectomy alone, whenever possible, seems to be associated to a better postoperative course and a trend towards lower cardiac mortality at follow-up, despite a higher rate of residual moderate MR.
Persistent end-diastolic forward flow after pulmonary valve replacement in patients with repaired tetralogy of Fallot
Authors: Tominaga Yuji , Taira Masaki , Kido Takashi , Kanaya Tomomitsu , Araki Kanta , Watanabe Takuji , Sakaniwa Ryoto , Toda Koichi , Kuratani Toru , Ueno Takayoshi , Sawa Yoshiki
Published: February 2021

OBJECTIVES

The clinical significance of persistent end-diastolic forward flow (EDFF) after pulmonary valve replacement (PVR) remains unclear in patients with repaired tetralogy of Fallot. This study aimed to identify the characteristics of these patients and the impact of persistent EDFF on outcomes.

METHODS

Of 46 consecutive patients who underwent PVR for moderate to severe pulmonary regurgitation between 2003 and 2019, 23 (50%) did not show EDFF before PVR [group (−)]. In the remaining 23 patients with EDFF before PVR, EDFF was diminished after PVR in 13 (28%) [group (+, −)] and persisted in 10 (22%) [group (+, +)]. The following variables were compared between these 3 groups: (i) preoperative right ventricular (RV) and right atrial volumes measured by magnetic resonance imaging, haemodynamic parameters measured by cardiac catheterization and the degree of RV myocardial fibrosis measured by RV biopsy obtained at PVR and (ii) the post-PVR course, development of atrial arrhythmia and need for intervention.

RESULTS

A high RV end-diastolic pressure, a greater right atrial volume index and a greater RV end-systolic volume index before PVR and a high degree of RV fibrosis were significantly associated with persistent EDFF 1 year after PVR. Persistent EDFF was a significant risk factor for postoperative atrial tachyarrhythmia, and catheter ablation and pacemaker implantation were required more frequently in these patients.

CONCLUSIONS

Persistent EDFF after PVR could predict a worse prognosis, especially an increased risk of arrhythmia. Close follow-up is required in patients with persistent EDFF for early detection of arrhythmia and prompt reintervention if necessary.

Clinical trial registration number

Institutional review board of Osaka University Hospital, number 16105
Exporting Pollution: Where Do Multinational Firms Emit CO2?
Authors: Ben-David Itzhak , Jang Yeejin , Kleimeier Stefanie , Viehs Michael
Published: February 2021

Despite widespread awareness of the detrimental impact of CO2 pollution on the world climate, countries vary widely in how they design and enforce environmental laws. Using novel microdata about multinational firms' CO2 emissions across countries, we document that firms headquartered in countries with strict environmental policies perform their polluting activities abroad in countries with relatively weaker policies. These effects are largely driven by tightened environmental policies in home countries that incentivize firms to pollute abroad rather than lenient foreign policies that attract those firms. Although firms headquartered in countries with strict domestic environmental policies are more likely to export pollution to foreign countries, they nevertheless emit somewhat less overall CO2 globally.
Distinct rhizomicrobiota assemblages and plant performance in lettuce grown in soils with different agricultural management histories
Authors: Babin Doreen , Sommermann Loreen , Chowdhury Soumitra Paul , Behr Jan H , Sandmann Martin , Neumann Günter , Nesme Joseph , Sørensen Søren J , Schellenberg Ingo , Rothballer Michael , Geistlinger Joerg , Smalla Kornelia , Grosch Rita
Published: February 2021

A better understanding of factors shaping the rhizosphere microbiota is important for sustainable crop production. We hypothesized that the effect of agricultural management on the soil microbiota is reflected in the assemblage of the rhizosphere microbiota with implications for plant performance. We designed a growth chamber experiment growing the model plant lettuce under controlled conditions in soils of a long-term field experiment with contrasting histories of tillage (mouldboard plough vs cultivator tillage), fertilization intensity (intensive standard nitrogen (N) + pesticides/growth regulators vs extensive reduced N without fungicides/growth regulators), and last standing field crop (rapeseed vs winter wheat). High-throughput sequencing of bacterial and archaeal 16S rRNA genes and fungal ITS2 regions amplified from total community DNA showed that these factors shaped the soil and rhizosphere microbiota of lettuce, however, to different extents among the microbial domains. Pseudomonas and Olpidium were identified as major indicators for agricultural management in the rhizosphere of lettuce. Long-term extensive fertilization history of soils resulted in higher lettuce growth and increased expression of genes involved in plant stress responses compared to intensive fertilization. Our work adds to the increasing knowledge on how soil microbiota can be manipulated by agricultural management practices which could be harnessed for sustainable crop production.
Genomic analyses of two Italian oyster mushroom Pleurotus pulmonarius strains
Authors: Vidal-Diez de Ulzurrun Guillermo , Lee Yi-Yun , Stajich Jason E , Schwarz Erich M , Hsueh Yen-Ping
Published: February 2021

Pleurotus mushrooms are among the most cultivated fungi in the world and are highly valuable for food, medicine, and biotechnology industries. Furthermore, Pleurotus species are carnivorous fungi; they can rapidly paralyze and kill nematodes when nutrient-deprived. The predator–prey interactions between Pleurotus and nematodes are still widely unexplored. Moreover, the molecular mechanisms and the genes involved in the carnivorous behavior of Pleurotus mushrooms remain a mystery. We are attempting to understand the interactions between Pleurotus mushrooms and their nematode prey through genetic and genomic analyses. Two single spores (ss2 and ss5) isolated from a fruiting body of Pleurotus pulmonarius exhibited significant differences in growth and toxicity against nematodes. Thus, using PacBio long reads, we assembled and annotated two high-quality genomes for these two isolates of P. pulmonarius. Each of these assemblies contains 23 scaffolds, including 6 (ss2) and 8 (ss5) telomere-to-telomere scaffolds, and they are among the most complete assembled genomes of the Pleurotus species. Comparative analyses identified the genomic differences between the two P. pulmonarius strains. In sum, this work provides a genomic resource that will be invaluable for better understanding the Italian oyster mushroom P. pulmonarius.
Application of an optimized annotation pipeline to theCryptococcus deuterogattiigenome reveals dynamic primary metabolic gene clusters and genomic impact of RNAi loss
Authors: Gröhs Ferrareze Patrícia Aline , Maufrais Corinne , Silva Araujo Streit Rodrigo , Priest Shelby J , Cuomo Christina A , Heitman Joseph , Staats Charley Christian , Janbon Guilhem
Published: February 2021

Evaluating the quality of a de novo annotation of a complex fungal genome based on RNA-seq data remains a challenge. In this study, we sequentially optimized a Cufflinks-CodingQuary-based bioinformatics pipeline fed with RNA-seq data using the manually annotated model pathogenic yeasts Cryptococcus neoformans and Cryptococcus deneoformans as test cases. Our results show that the quality of the annotation is sensitive to the quantity of RNA-seq data used and that the best quality is obtained with 5–10 million reads per RNA-seq replicate. We also showed that the number of introns predicted is an excellent a priori indicator of the quality of the final de novo annotation. We then used this pipeline to annotate the genome of the RNAi-deficient species Cryptococcus deuterogattii strain R265 using RNA-seq data. Dynamic transcriptome analysis revealed that intron retention is more prominent in C. deuterogattii than in the other RNAi-proficient species C. neoformans and C. deneoformans. In contrast, we observed that antisense transcription was not higher in C. deuterogattii than in the two other Cryptococcus species. Comparative gene content analysis identified 21 clusters enriched in transcription factors and transporters that have been lost. Interestingly, analysis of the subtelomeric regions in these three annotated species identified a similar gene enrichment, reminiscent of the structure of primary metabolic clusters. Our data suggest that there is active exchange between subtelomeric regions, and that other chromosomal regions might participate in adaptive diversification of Cryptococcus metabolite assimilation potential.
Research on photovoltaic system MPPT based on IFOINC algorithm
Authors: Du Yuhe , Liao Yu , Liu Yichu , Ji Jianwei
Published: February 2021

Aiming at the shortcomings of traditional maximum power point tracking (MPPT) algorithm in photovoltaic system, such as slow tracking speed, easy oscillation and low tracking accuracy, an improved fractional order incremental conductivity (IFOINC) method is proposed. The algorithm combines the variable step-size Peturb and Observe (P & O) method based on power prediction and fractional order conductance increment method. Firstly, the variable step-size P & O method based on power prediction is used to quickly track the MPP, and then the fractional order incremental conductance method is used to further search the MPP. The structure of photovoltaic system, the equivalent model of photovoltaic cells and the DC/DC converter are studied. The IFOINC algorithm is designed, and the MPPT simulation model of photovoltaic system is established. The simulation is carried out in MATLAB/Simulink software environment. The simulation results show that the tracking speed of IFOINC is improved by 42.3% compared with the variable step-size P & O method based on power prediction, and the tracking accuracy of 3.9% higher than that of the variable step-size P & O method, based on power prediction, and the oscillation is eliminated.
How to avoid unnecessary surgical treatment for neonatal small left colon syndrome
Authors: Ikeda Taro , Goto Shumpei , Hosokawa Takashi , Rikiyama Toshiki , Hosono Shigeharu , Takagi Kenjiro
Published: February 2021

We report a case of neonatal small left colon syndrome (NSLCS) that underwent surgery. A female infant was born at 38 weeks of gestation. The mother had gestational diabetes requiring insulin therapy. The baby was admitted for respiratory distress. Abdominal distension was observed, and the gastric residue increased. Contrast enema revealed a small caliber of the left colon up to the splenic flexure. At 14 days, the full-thickness biopsy of the sigmoid and transverse colons was performed. Pathological diagnosis showed that the sigmoid colon had few ganglion cells, therefore the transverse colostomy was performed. At 6 months of age, a rectal biopsy was performed to confirm the diagnosis of Hirschsprung’s disease; the intestinal plexus and ganglion cells were normal. The surgery was changed from a pull-through to a stoma closure. The postoperative diagnosis was NSLCS, and the course up to 3 years was good without defecation or growth problems.
Unusual segmental ischemia of the small bowel from cocaine abuse
Authors: Grottesi Alfonso , Bianchi Leonello , Ranieri Francesco Maria , Puce Ernesto , Catarci Marco
Published: February 2021

Cocaine abuse is rising in the young population, triggering uncommon and potentially life-threatening causes of acute abdomen in this age group. The authors present the case of a 30-year-old man with emergency admission due to abdominal pain, with no history of drug abuse. Several signs and symptoms elicited toxicologic blood screening, which disclosed high serum levels of cocaine and its metabolites. Twelve hours after admission, the onset of acute abdomen with signs of diffuse peritonitis prompted surgical exploration through a minimally invasive approach. Two segmental small bowel ischemic loops and diffuse peritonitis, but no bowel perforation, were identified and treated by laparoscopic peritoneal lavage with 5 l of heated saline and intravenous administration of sodium heparin, 10 000 IU. Postoperative course was uneventful with home discharge on postoperative day 5. High index of suspicion is required to establish a prompt diagnosis and treatment of this uncommon cocaine abuse-related disease.
Coevolutionary and Phylogenetic Analysis of Mimiviral Replication Machinery Suggest the Cellular Origin of Mimiviruses
Authors: Patil Supriya , Kondabagil Kiran
Published: February 2021

Mimivirus is one of the most complex and largest viruses known. The origin and evolution of Mimivirus and other giant viruses have been a subject of intense study in the last two decades. The two prevailing hypotheses on the origin of Mimivirus and other viruses are the reduction hypothesis, which posits that viruses emerged from modern unicellular organisms; whereas the virus-first hypothesis proposes viruses as relics of precellular forms of life. In this study, to gain insights into the origin of Mimivirus, we have carried out extensive phylogenetic, correlation, and multidimensional scaling analyses of the putative proteins involved in the replication of its 1.2-Mb large genome. Correlation analysis and multidimensional scaling methods were validated using bacteriophage, bacteria, archaea, and eukaryotic replication proteins before applying to Mimivirus. We show that a large fraction of mimiviral replication proteins, including polymerase B, clamp, and clamp loaders are of eukaryotic origin and are coevolving. Although phylogenetic analysis places some components along the lineages of phage and bacteria, we show that all the replication-related genes have been homogenized and are under purifying selection. Collectively our analysis supports the idea that Mimivirus originated from a complex cellular ancestor. We hypothesize that Mimivirus has largely retained complex replication machinery reminiscent of its progenitor while losing most of the other genes related to processes such as metabolism and translation.
Brassinosteroids Influence Arabidopsis Hypocotyl Graviresponses through Changes in Mannans and Cellulose
Authors: Somssich Marc , Vandenbussche Filip , Ivakov Alexander , Funke Norma , Ruprecht Colin , Vissenberg Kris , VanDer Straeten Dominique , Persson Staffan , Suslov Dmitry
Published: February 2021

The force of gravity is a constant environmental factor. Plant shoots respond to gravity through negative gravitropism and gravity resistance. These responses are essential for plants to direct the growth of aerial organs away from the soil surface after germination and to keep an upright posture above ground. We took advantage of the effect of brassinosteroids (BRs) on the two types of graviresponses in Arabidopsis thaliana hypocotyls to disentangle functions of cell wall polymers during etiolated shoot growth. The ability of etiolated Arabidopsis seedlings to grow upward was suppressed in the presence of 24-epibrassinolide (EBL) but enhanced in the presence of brassinazole (BRZ), an inhibitor of BR biosynthesis. These effects were accompanied by changes in cell wall mechanics and composition. Cell wall biochemical analyses, confocal microscopy of the cellulose-specific pontamine S4B dye and cellular growth analyses revealed that the EBL and BRZ treatments correlated with changes in cellulose fibre organization, cell expansion at the hypocotyl base and mannan content. Indeed, a longitudinal reorientation of cellulose fibres and growth inhibition at the base of hypocotyls supported their upright posture whereas the presence of mannans reduced gravitropic bending. The negative effect of mannans on gravitropism is a new function for this class of hemicelluloses. We also found that EBL interferes with upright growth of hypocotyls through their uneven thickening at the base.
Do Corticosteroid Injections for the Treatment of Pain Influence the Efficacy of mRNA COVID-19 Vaccines?
Authors: Lee Haewon , Punt Jennifer A , Miller David C , Nagpal Ameet , Smith Clark C , Sayeed Yusef , Patel Jaymin , Stojanovic Milan P , Popescu Adrian , McCormick Zachary L ,   the Spine Intervention Society’s Patient Safety Committee
Published: February 2021

Myth

Corticosteroid injection for the treatment of pain and inflammation is known to decrease the efficacy of the messenger ribonucleic acid (mRNA) vaccines for coronavirus disease 2019 (COVID-19).

Fact

There is currently no direct evidence to suggest that a corticosteroid injection before or after the administration of an mRNA COVID-19 vaccine decreases the efficacy of the vaccine.

However, based on the known timeline of hypothalamic-pituitary-adrenal (HPA) axis suppression following epidural and intraarticular corticosteroid injections, and the timeline of the reported peak efficacy of the Pfizer-BioNTech and Moderna vaccines, physicians should consider timing an elective corticosteroid injection such that it is administered no less than 2 weeks prior to a COVID-19 mRNA vaccine dose and no less than 1 week following a COVID-19 mRNA vaccine dose, whenever possible.