bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of changes in tricuspid regurgitation on clinical outcomes following mitral valve teer compared to guideline-directed medical therapy: a sub-analysis of the COAPT trial
Authors: Lehenbauer K , Asch F , Weissman NJ , Grayburn P , Kar S , Lim S , Li D , Puri R , Kapadia S , Sannino A , Lindenfeld J , Abraham W , Mack MJ , Stone GW , Hahn R
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT)

Background

Prior studies suggest tricuspid regurgitation (TR) diminishes/resolves following mitral valve surgery and thus do not require treatment and may not influence outcomes.

Purpose

  We sought to evaluate the change in TR (ΔTR) and its association with outcomes after transcatheter edge-to-edge repair (TEER) compared with guideline-directed medical therapy (GDMT) in the COAPT trial.

Methods

Patients from the COAPT trial with echo core lab TR assessment at baseline and 30-day follow-up (n = 504) were included and divided into 2 groups: those whose TR worsened (ΔTR-INC) and those with no change or improvement in TR (ΔTR-SAME/DEC).  Two-year composite endpoints of death or heart failure hospitalization (HFH) and the individual components were analyzed, after excluding events occurring within the first 30 days.

Results

ΔTR-SAME/DEC occurred in 430 pts (228 TEER, 202 GDMT) while ΔTR-INC was noted in 74 pts (38 TEER, 36 GDMT) (Figure 1A). From 30 days to 2 years, ΔTR-INC pts had a higher rate of the composite outcome of death or HFH compared with ΔTR-SAME/DEC (p = 0.006, Figure 1B). Both 2-year death (HR 1.52, 95% CI 1.01-2.27; p = 0.04) and HFH (HR 1.52, 95% CI 1.04-2.22; p = 0.03) were associated with ΔTR-INC. Assessed by treatment group (Figure 1C and 1D), the relationship between ΔTR-INC and composite death or HFH was significant in GDMT alone pts (HR 1.86, 95% CI 1.21-2.86) but not in TEER pts (HR 1.33, 95% CI 0.79-2.23), although interaction testing demonstrated consistency between the two treatments  (Pint = 0.31). 

Conclusions

Worsening TR at 30 days occurred in ∼15% of pts in the COAPT trial whether they were treated with TEER or GDMT alone. DTRINC was associated with increased death and HFH during 2-year follow-up. Abstract Figure 1
Right ventricular remodelling in patients with significant tricuspid regurgitation undergoing tricuspid valve surgery
Authors: Galloo X , Meucci MC , Stassen J , Dietz MF , Prihadi EA , Van Der Bijl P , Ajmone Marsan N , Braun J , Bax JJ , Delgado V
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Inconsistent changes in right ventricular (RV) dimensions and function have been observed after tricuspid valve (TV) surgery and their associations with long-term outcomes have not been explored.

Purpose

To evaluate RV remodelling and RV function in patients with significant (moderate or severe) tricuspid regurgitation (TR) undergoing TV surgery and their association with outcome.

Methods

A total of 121 patients (mean age 63 ± 12 years, 47% male) with significant TR treated with TV surgery and who had an echocardiogram between 3 months and 1 year of follow-up, were included for this analysis. Remodelling was assessed by comparing dimensions and function at follow-up to baseline values. The population was stratified by tertiles of percentage reduction of RV end-systolic area (RVESA) and absolute change of RV fractional area change (RVFAC). Five-year mortality rates were compared across the tertiles of RV remodelling and the independent associates of mortality were investigated.

Results

Reduction in RVESA and improvement in RVFAC were significantly associated with better survival after TV surgery, whereas reduction in RV end-diastolic area was not (Figure 1). One third of the patients presented with a reduction in RVESA of at least 17.2% and improvement in RVFAC of at least 2.3%, constituting the third tertiles for comparison. Kaplan-Meier curves for overall survival according to RVESA- and RVFAC-tertiles are shown in Figure 2. Cumulative survival rates were significantly better in patients in the third tertile of RVESA reduction: 49%, 69%, and 90% for tertile 1, tertile 2, and tertile 3, respectively (log-rank chi-square: 12.526; p = 0.002); as well as according to RVFAC improvement: 57%, 65%, and 87% for tertile 1, tertile 2, and tertile 3, respectively (log-rank chi-square: 7.784; p = 0.02). Tertile 3 of RVESA-reduction as well as tertile 3 of RVFAC-change were both independently associated with better survival after TV surgery compared to tertile 1 (hazard ratio: 0.221 [95% CI: 0.074 to 0.658] and 0.327 [95% CI: 0.118 to 0.907], respectively).

Conclusion

The magnitude of RV reverse remodelling (based on reduction in RVESA) and improvement in RVFAC were associated with better survival at 5 years’ follow-up after TV surgery for significant TR. Abstract Figure 1: Spline curves  Abstract Figure 2: KM curves for overal survival
Can aortic calcium score predict new conduction disturbances in pos-transcatheter aortic valve implantation?
Authors: Costa C , Calvao J , Amador A , Proenca T , Carvalho M , Pinto R , Marques C , Cabrita A , Grilo PD , Resende CX , Torres S , Sousa C , Macedo F
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Transcatheter aortic valve implantation (TAVI) may be the first line treatment for severe aortic stenosis according to overall patient characteristics. Semi-quantitative Agatston score (AS), which quantifies aortic calcium by cardiac computed tomography (CCT), has knowledgeable practical and clinical implications, and is performed in TAVI diagnostic workup. Since conduction disturbances continue to be the most frequent complication, further refinements are required to predict high-risk patients.

Purpose

To access if aortic AS relates with new conduction disturbances and permanent pacemaker (PPM) implantation in patients undergoing TAVI.

Methods

We retrospectively analyzed all patients who underwent TAVI at a tertiary center from October 2014 to November 2019; patients with previous permanent pacemaker (PPM) or had no aortic AS were excluded. Clinical and electrocardiogram (ECG) data were collected at admission and after the procedure. All categorical variables are reported as numbers and percentages. Continuous variables were analyzed using the two-tailed unpaired Student’s t-test and are reported as mean values and the standard deviation. Statistical analysis was performed using the IBM SPSS.

Results

172 patients with a mean age 79 ± 9.1 years old were included (see table 1 for baseline characteristics). AS was on average 3008 ± 2262 (see table 2 for remaining diagnostic workup and procedure characteristics).

Comparing AS with new conduction disturbances, no statistically significant difference was found for new complete left branch block (LBBB) (no vs new LBBB, AS: 3179 ± 2555 vs 2637 ± 1388, p= 0,15) and with new complete atrioventricular block (AVB) (no vs new AVB, AS: 2834 ± 1520 vs 4485 ± 5285, p = 0.2). Considering PPM implantation after TAVI, there was a tendency for higher AS and PPM implantation (no vs PPM implantation, AS: 2756 ± 1451 vs 4242 ± 4310, p = 0.07).

In patients who had pre-ballooning, there was no difference relating to AS; however, in patients who had no pre-ballooning there was a trend to higher AS and PPM implantation (no vs PPM implantation, AS: 2417 ± 1301 vs 4616 ± 4969, p = 0.06). No statistically significant difference was found when comparing earlier (Portico, CoreValve Evolut R) vs newer valves (CoreValve Evolut Pro; Edward Sapiens 3; Accurate Neo).

Conclusion

Aortic calcium measured by Agatston score did not show a correlation with new LBBB or new AVB after TAVI. Nevertheless, it seems to be a trend for higher AS and PPM implantation; this was more noticeable when pre-ballooning was not performed. Further studies are needed in order to further elucidate this association. Abstract Figure. Patients baseline characteristics  Abstract Figure. TAVI diagnostic workup and procedure
Echocardiographic predictors of left ventricular reverse remodeling after aortic valve replacement in patients with paradoxical aortic stenosis
Authors: Zafirovska P , Georgievska - Ismail L , Andova V , Matveeva N , Idoski E , Mitrev Z
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Paradoxical aortic stenosis (AS) is low-flow (SVi ≤ 35ml/m2) , low- gradient (Mean PG ≤ 40mmHg) severe aortic stenosis (AVA < 1cm2) in patients with preserved ejection fraction (EF ≥ 50%) usually associated with female gender, advanced age, small body size and history of hypertension. Left ventricular (LV) reverse remodeling presents with LV hypertrophy reversal following aortic valve replacement (AVR) and is associated with better long term prognosis.

Purpose

The purpose of our study was to asses echocardiographic predictors of better outcome in patients with paradoxical severe AS following AVR.

Methods

Detailed transthoracic echocardiographic (TTE) evaluation with left ventricular strain analysis was performed using 2D Philips Epique 7 in patients with severe aortic stenosis with AVR indication before and 4 months after the intervention.

Results

Among 75 patients with severe AS and indication for AVR, 20 (31, 7%) were paradoxical AS with low- flow, low –gradient and preserved ejection fraction. Sixty percent were female and eighty percent had hypertension where all echocardiographic parameters improved following AVR including improvement of LV global longitudinal strain (LS) as well as reduction of left ventricular mass indicating left ventricular reverse remodeling (Figure 1). The patients with paradoxical AS compared to the other forms of severe AS had the lowest values for MAPSE and s’TDI before and after AVR. Independent predictors of LV reverse remodeling before AVR were end systolic LV volume (ESV) , AVA/BSA and the number of segments with LS < 13%.

Conclusion

Paradoxical severe AS is associated with worse post AVR prognosis compared to the high gradient severe AS.  Echocardiographic predictors of LV reverse remodeling in patients with paradoxical severe AS following AVR are LV ESV, AVA/BSA and number of segments with LS < 13%. Timely diagnosis and AVR referral of patients with paradoxical severe AS is of major importance in the management of aortic valvular disease. Abstract Figure. Descriptive of 20pts with paradoxical AS  Abstract Figure. Predictors of LV reverse remodeling
Echocardiographic predictors of outcome after isolated tricuspid valvular surgery
Authors: Eggenspieler F , Huttin O , Erpelding ML , Filippetti L , Pace N , Popovic B , Sirbu C , Elfarra M , Maureira P , Selton Suty C
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Right ventricular (RV) function is one factor influencing outcome after isolated tricuspid valve surgery (ITVS). As it is highly load dependant, its echocardiographic assessment requires a multiparametric analysis.

Purpose

To assess prognostic value of RV echocardiographic parameters among patients undergoing ITVS.

Methods

Preoperative echocardiograms were retrospectively reviewed in 75 patients (mean age 54 ± 17 years) who underwent ITVS between 2007 and 2020. We assessed classical parameters of RV load, morphology and function, and calculated a load-remodeling-function index (LRFI) combining load (using tricuspid regurgitation time-velocity integral), remodeling (using ratio of RV diameter / length) and function (using strain rate (SR)). Those parameters were compared between alive and dead patients at 1-year follow-up.

Results

Mortality rate was 17.3% at 1 year and 22.7% at 5 years. Among standard RV function parameters, only S’ and SR were significantly lower in dead than in alive patients at 1 year.

LRFI was significantly higher in dead patients at 1-year. By analysis of ROC curve, LRFI (AUC 0.823 [0.678-0.968]; p = 0.002) was the best predictor of death at 1 year.

When associating a clinical variable (pre-existing right heart failure (RHF)) and LRFI, Kaplan Meier curves showed significantly higher mortality in patients with both RHF and altered LRFI.

Conclusion

Global RV analysis using a parameter combining load, remodeling and function may help in the prognostic assessment of patients undergoing ITVS, in addition to the presence of RHF.
Machine learning predicts all-cause mortality in patients with severe aortic regurgitation
Authors: Anand V , Hu H , Weston AD , Scott CG , Michelena HI , Pislaru SV , Carter RE , Pellikka PA
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Aortic regurgitation (AR) is a common valvular lesion associated with left ventricular (LV) enlargement and dysfunction and increased risk of death with onset of symptoms, significant LV enlargement, or systolic dysfunction. The current guidelines are based on symptoms, LV size and LV function to evaluate the candidacy for surgery in patients with severe AR.

Purpose

 We propose a machine-learning (ML) based algorithm to identify patients at risk for death from AR independent of aortic valve replacement (AVR) surgery (patients were censored at AVR event unless the operation occurred within 100 days of the first visit, in which case baseline AVR is included as a predictor).

Methods

The model was trained with 5-fold cross-validation on a dataset of 1035 patients. Model performance is reported on an independent dataset of 207 patients. Optimal predictive performance was observed with a Conditional Random Survival Forest model. A subset of 19 / 41 variables were selected for inclusion in the final model. Variable selection was performed with 10-fold cross validation using Random Survival Forest model; variables that were on an average selected by less than 6/10 splits were excluded.

Results

The mean age of patients was 60 ± 17 years and 198 (18%) were females. The variables included in the models were age, end-diastolic volume, end systolic dimension, body surface area, ejection fraction, NYHA class, body mass index, diastolic blood pressure, bicuspid valve, regurgitant volume, filling pressure, mid ascending aorta diameter, mitral tissue early relaxation velocity, pulmonary artery systolic pressure, and comorbidities, and the relative variable importances averaged across five splits of cross validation in each repeat were evaluated (Figure). The predictive AUC for predicting survival of the best-performing model was 0.84 at 1 year, 0.86 at 2 years, and 0.87 overall, respectively.

Conclusion

Using commonly observed echo parameters and patient characteristics we successfully trained a ML model to predict survival in patients with severe AR. This technique could identify high-risk patients who would benefit from early intervention, thereby improving patient outcomes. Abstract Figure.
Left atrial myopathy and mitral regurgitation in hypertrophic cardiomyopathy
Authors: Zegkos T , Kamperidis V , Gossios T , Ntelios D , Parcharidou D , Papanastasiou CA , Katranas S , Rouskas P , Karvounis H , Efthimiadis GK
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Recent studies have shown that mitral regurgitation (MR) represents a major determinant of left atrial (LA) function in patients with heart failure with preserved ejection fraction. The role of MR in determining LA myopathy in hypertrophic cardiomyopathy (HCM) is unknown.

Purpose

The aim of this study was to examine the association of MR with LA myopathy, assessed by LA strain in HCM patients.

Methods

 In total 250 consecutive patients (mean age 51 ± 16years, 67.2% male) with an established diagnosis of HCM and with sinus rhythm at index echocardiography evaluation were included. LA reservoir, conduit and booster strain were analyzed, besides LA size, left ventricular (LV) systolic and diastolic function. The predictors of LA strain values were identified with linear regression analysis.

Results

More than mild MR was a significant univariate predictor of all the three LA strain values. In multivariate linear regression analysis, independent predictors of LA reservoir strain were more than mild MR (r= -0.23), LV global longitudinal strain (r= -0.49), LA volume index (r= -0.27) and patient age (r= -0.22). More than mild MR was also an independent determinant of LA conduit (r=-0.17) and booster strain (r=-0.12) (Table 1). In patients with LA volume index <34ml/m2 more than mild MR was an independent predictor of LA reservoir (r= -0.32) and conduit strain (r= -0.27), but not LA booster strain (Table 2).

Conclusion

The severity of MR is associated with LA myopathy with independently of the LV diastolic and systolic function and LA size. Abstract Table 1  Abstract Table 2
Cardiac masses and contrast echocardiography
Authors: Lanzoni L , Bonapace S , Dugo C , Chiampan A , Anselmi A , Ghiselli L , Molon G
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

echocardiography may be the first imaging modality detecting a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast echocardiography may aid in the differential diagnosis. Methods: we describe five cardiac masses in which echo-contrast helped to assess the presence or not of vascularization. Panel A shows a left atrial mass attached to the fossa ovalis with a large stalk prolapsing to the mitral inflow. Contrast echocardiography showed late but homogeneous opacification of the mass. Gross pathology confirmed an atrial mixoma. Panel B shows two masses in a patient with non-small cell lung cancer one embedded in the inferior left ventricular wall and the other floating in the left atrium. Administration of echo-contrast showed late and inhomogeneous enhancement of the myocardial mass and absent opacification of the atrial mass suggesting a metastatic infiltration of the myocardium together with an avascular neoplastic thrombus in the left atrium. Panel C shows a multi-lobulated and mobile mass in the right atrium straddling the tricuspid valve. Contrast echocardiography highlighted an inhomogeneous diffusion of the contrast within the mass with a rapid opacification only of its atrial portion. Gross pathology confirmed a recurrent thymoma. Panel D shows an intraventricular mass arising from the interventricular septum with multiple hypoechoic areas in a patient with metastatic carcinoid. Contrast administration showed a very late and mild degree of inhomogeneous enhancement. Conclusion:  the echo-contrast allows a good differentiation between vascularized and non-vascularized cardiac masses, providing an important indication to differentiate thrombus from tumor. In those hypervascularized masses the homogeneous or inhomogeneous distribution of the contrast could be an interesting clue that orientates between primary or secondary cardiac tumors. Abstract Figure.
Pulmonary artery pulsatility index by echocardiography predicts mortality in patients with pulmonary hypertension
Authors: Kane CJ , Chung SY , Anand V , Kane GC , Pislaru SV , Lin G
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary hypertension (PH) is a progressive pulmonary vascular disorder with an elevated mortality risk due to right ventricular failure. Pulmonary arterial pulsatility index (PAPi) based on invasively acquired parameters has emerged as a potentially valuable hemodynamic risk predictor. Whether non-invasively derived PAPi (PA pulse pressure/ RA pressure) is valuable is unclear.

Purpose

To assess whether PAPi measured non-invasively by transthoracic echocardiography acts as a prognostic hemodynamic biomarker of patient risk.

Methods

Consecutive patients undergoing transthoracic echocardiography for known or suspected PH over a one year period were included. PA systolic and diastolic pressure were estimated in standard fashion from peak tricuspid and end-pulmonary regurgitant Doppler profiles. Right atrial pressure was estimated based on 2D & Doppler assessment of the inferior vena cava  hepatic vein. In those patients with PH (mean PA pressure > 20 mm Hg), PAPi was divided into 3 groups based on prior publications with invasive data as <1.5, 1.5 to 3 and >3. Mortality was assessed over 5 years.

Results

Of 1,045 patients enrolled 64% had PH. Patients with the lowest PAPi (table) had higher NT-proBNP levels, larger right ventricles, worse right heart systolic function (cardiac output, TAPSE, systolic annular velocity, free wall systolic strain) and greater degrees of tricuspid regurgitation (Table). In patients with PH, PAPi was inversely associated with death (figure, p < 0.0001) with each group of PAPi correlating with incrementally worse survival. Patients with a PAPi of <1.5 had worst right heart size and dysfunction on echo (table) and worst survival (figure).

Conclusions

In patients with PH, low PAPi derived non-invasively by transthoracic echocardiography is associated with markers of right heart failure, right ventricular dysfunction and worse survival. PAPi could be incorporated into the conventional echo parameters reported in patients with known or suspected PH and maybe a useful predictor of outcome. Abstract Table  Abstract Figure
Determinants of left atrioventricular coupling index as a prognostic marker of cardiovascular events from the multi-ethnic atherosclerosis study (MESA)
Authors: Pezel T , Ambale Venkatesh B , De Vasconcellos H , Kato Y , Post W , Wu C , Heckbert S , Bluemke D , Logeart D , Henry P , Lima J
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

Recent studies have emphasized the incremental prognostic value of a novel left atrioventricular coupling index (LACI) and its 10-year annual change (ΔLACI) to predict cardiovascular events. However, no study has investigated the potential determinants of this index.

PURPOSE

To identify the determinants of LACI and ΔLACI, measured by cardiovascular magnetic resonance (CMR), and to better understand the parameters governing this left atrioventricular coupling in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

In the MESA, 2,112 study participants, free of cardiovascular disease at baseline, had LACI assessed by CMR imaging at baseline (LACIBaseline, Exam 1, 2000–2002) and 10 years later (Exam 5, 2010–2012). The LACI was defined as the ratio of left atrium to left ventricular (LV) end-diastolic volumes. Multivariable linear regression analyses were performed, adjusting for traditional risk factors and LV structure, to identify independent determinants of LACIBaseline or ΔLACI.

RESULTS

In the 2,112 participants (mean age 58.8 ± 9.1 years and 46.6% male), after adjustment for all covariates, age was independently associated with both LACIBaseline (R2 = 0.10) and ΔLACI (R2 = 0.15, both p < 0.001). Although there was no difference in LACIBaseline between women and men (p = 0.19), ΔLACI was higher in women than in men (1.0 ± 1.1 vs. 0.8 ± 1.0 %/year, p < 0.001). African Americans had the highest LACIBaseline value (18.0 ± 7.7%) while Chinese Americans had the lowest (13.8 ± 6.4%, p < 0.001). Diabetes and a higher body mass index were independently associated with LACIBaseline (coefficients B: 1.75 and 0.24, respectively, both p < 0.001). LACIBaseline was independently associated with LV myocardial fibrosis markers (native T1: R2 = 0.11, p = 0.038; and extra-cellular volume [ECV]: R2 = 0.08, p = 0.035) and NT-proBNP levels (R2 = 0.10, p < 0.001) but was not associated with inflammation biomarkers.

CONCLUSIONS

In a multi-ethnic population, age, sex, ethnicity, diabetes, and a higher body mass index were independent determinants of LACI. LACI was independently associated with LV myocardial fibrosis markers and NT-proBNP levels but not associated with inflammation biomarkers.

ClinicalTrials.gov Identifier: NCT00005487 Abstract Figure. Relationship between LACI and Age  Abstract Figure. Relationship between LACI and Gender
Radiological cardiothoracic ratio as a potential predictor of right ventricular enlargement in patients with suspected pulmonary embolism due to COVID-19
Authors: Gac P , Truszkiewicz K , Poreba M , Poreba R
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Objective. Cases of pulmonary embolism are observed in the course of COVID-19. Right ventricular enlargement is a negative prognostic factor of pulmonary embolism. The cardiothoracic ratio is a routine parameter in the cardiac assessment in chest radiology.

Purpose. The aim of the study was to determine the usefulness of the radiological cardiothoracic ratio (CTR) as a predictor of right ventricular enlargement in patients with suspected pulmonary embolism during COVID-19.

Material and method. The study group consisted of 61 patients with confirmed COVID-19, suspected of pulmonary embolism based on physical examination and laboratory tests (age: 67.18 ± 12.47 years). Computed tomography angiography (CTA) of pulmonary arteries and chest radiograph in AP projection with cardiothoracic ratio assessment were performed in all patients. Right ventricular enlargement was diagnosed by the ratio of right ventricular to left ventricular (RV/LV) dimensions in pulmonary CTA with 2 cut-off points: ≥0.9 and ≥1.0. Heart’s silhouette enlargement was found when CTR on the chest radiograph in the projection AP >0.55.

Results. The mean values of RV/LV and CTR in the studied group were 0.96 ± 0.23 and 0.57 ± 0.05. Pulmonary embolism was diagnosed in 45.9%. Right ventricular enlargement was documented in 44.3% or 29.5% depending on the adopted criterion RV/LV ≥0.9 or RV/LV ≥1.0. Heart’s silhouette enlargement was found in 60.6%. Patients with confirmed pulmonary embolism (PE+) had significantly higher RV/LV ratio and CTR than patients with excluded pulmonary embolism (PE-) (RV/LV: PE+ 1.08 ± 0.24, PE- 0.82 ± 0.12; CTR: PE+ 0.60 ± 0.05, PE- 0.54 ± 0.04; p < 0.05). The correlation analysis showed a statistically significant positive correlation between RV/LV ratio and CTR (r = 0.59, p < 0.05). Based on the ROC curves, CTR values were determined as the optimal cut-off points for the prediction of right ventricular enlargement (RV/LV ≥0.9 or RV/LV ≥1.0), being 0.54 and 0.55, respectively. The sensitivity, specificity, and accuracy of the CTR criterion >0.54 as a predictor of RV/LV ratio ≥0.9 was 0.412, 0.963, and 0.656, respectively, while the CTR criterion >0.55 as a predictor of RV/LV ratio ≥1.0 was 0.488, 0.833, and 0.590, respectively.

Conclusions. In patients with suspected pulmonary embolism during COVID-19, radiographic cardiothoracic ratio may be a predictor of right ventricular enlargement, especially a negative predictor of right ventricular enlargement in case of lower CTR values.
Feasibility of sonothrombolysis in the ambulance for ST-elevation myocardial infarction
Authors: El Kadi S , Porter TR , Zanstra M , Siegers A , Van Loon RB , Hopman LHGA , Van Rossum AC , Kamp O
Published: February 2022

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Lantheus Medical Imaging, Inc., North Billerica, MA

Background

Patients with ST-elevation myocardial infarction (STEMI) due to coronary occlusion require immediate restoration of epicardial and microvascular blood flow. A potentially new reperfusion method is the use of ultrasound and microbubbles, also called sonothrombolysis. The oscillation and collapse of intravenously administered microbubbles upon exposure to high mechanical index (MI) ultrasound pulses results in thrombus dissolution and stimulates nitric oxide-mediated increases in tissue perfusion. The aim of this study was to assess feasibility of sonothrombolysis in the ambulance for STEMI patients.

Methods

Patients presenting with chest pain and ST-elevations on initial electrocardiogram were included. Sonothrombolysis was applied in the ambulance during patient transfer to the percutaneous coronary intervention (PCI) center. Feasibility was assessed based on duration of sonothrombolysis treatment and number of high MI pulses applied. Vital parameters, ST-resolution, pre- and post-PCI coronary flow and cardiovascular magnetic resonance images were analyzed. Follow up was performed at six months after STEMI.

Results

Twelve patients were screened, of which three patients were included in the study. Sonothrombolysis duration and number of high MI pulses ranged between 12-17 minutes and 32-60 flashes respectively. No changes in vital parameters were observed during and directly after sonothrombolysis. In one case, sonothrombolysis on top of regular pre-hospital care resulted in reperfusion, in another case the effect was inconclusive, and in the last case no effect was seen on reperfusion or definite infarct size.

Conclusion

Sonothrombolysis in the ambulance for STEMI patients is feasible. Larger clinical trials on efficacy and safety of pre-hospital sonothrombolysis are needed. Abstract Figure. Sonothrombolysis set-up in the ambulance  Abstract Figure. Sonothrombolysis case with reperfusion
A multivariate statistical approach in correlating the acoustic properties with petrophysics and mineralogy on sandstones
Authors: Garia Siddharth , Pal Arnab Kumar , Ravi K , Nair Archana M
Published: February 2022

We examined the effects of the petrophysical and mineralogical variables on the acoustic properties of Upper Assam sandstones. All parameters were evaluated in the laboratory using recognized standard laboratory methods. Compressional wave velocity was measured in the laboratory using piezoelectric transducers of 54 kHz by using the ultrasonic-through transmission technique. Single parameter correlations among bulk density, porosity, permeability and mineralogy with compressional wave velocity showed that the compressional wave velocity correlated inversely with porosity, permeability and feldspar content and directly with bulk density and quartz content. For instance, a plug with a higher amount of feldspar content showed a corresponding decrease in compressional wave velocity. Similarly, higher quartz content showed a higher compressional wave velocity. Nevertheless, to depict a clear correlation among different parameters, a multiparameter analysis was performed. It was observed that the coefficient of determination improved from 0.596 to 0.899 when compressional wave velocity was modelled in terms of bulk density, porosity, quartz and feldspar content collectively, rather than when compressional wave velocity was modelled as a function of porosity alone. Hence, our study suggests that multiple parameters exhibit a coherent influence on compressional wave velocity. Therefore, a multivariate statistical approach involving petrophysical and mineralogical influences would be more realistic. Furthermore, major mineral fractions of sandstone rock type, that is quartz and feldspar fractions were varied for a range of porosity to determine the variations in compressional wave velocity for different saturation conditions. Capturing the fluctuations in compressional wave velocity within the geological constraints will aid in possible reservoir characterization away from the well-control or beyond the available data range. The integrated approach can result in more accurate and precise rock physics models that may help to infer key reservoir parameters. The developed models can be used in quantitative seismic interpretation for reservoir characterization and to identify prospective reservoirs.
Effect of remdesivir on viral dynamics in COVID-19 hospitalized patients: a modelling analysis of the randomized, controlled, open-label DisCoVeRy trial
Authors: Lingas Guillaume , Néant Nadège , Gaymard Alexandre , Belhadi Drifa , Peytavin Gilles , Hites Maya , Staub Thérèse , Greil Richard , Paiva Jose-Artur , Poissy Julien , Peiffer-Smadja Nathan , Costagliola Dominique , Yazdanpanah Yazdan , Wallet Florent , Gagneux-Brunon Amandine , Mentré France , Ader Florence , Burdet Charles , Guedj Jérémie , Bouscambert-Duchamp Maude
Published: February 2022

Background

The antiviral efficacy of remdesivir in COVID-19 hospitalized patients remains controversial.

Objectives

To estimate the effect of remdesivir in blocking viral replication.

Methods

We analysed nasopharyngeal normalized viral loads from 665 hospitalized patients included in the DisCoVeRy trial (NCT 04315948; EudraCT 2020-000936-23), randomized to either standard of care (SoC) or SoC + remdesivir. We used a mathematical model to reconstruct viral kinetic profiles and estimate the antiviral efficacy of remdesivir in blocking viral replication. Additional analyses were conducted stratified on time of treatment initiation (≤7 or >7 days since symptom onset) or viral load at randomization (< or ≥3.5 log10 copies/104 cells).

Results

In our model, remdesivir reduced viral production by infected cells by 2-fold on average (95% CI: 1.5–3.2-fold). Model-based simulations predict that remdesivir reduced time to viral clearance by 0.7 days compared with SoC, with large inter-individual variabilities (IQR: 0.0–1.3 days). Remdesivir had a larger impact in patients with high viral load at randomization, reducing viral production by 5-fold on average (95% CI: 2.8–25-fold) and the median time to viral clearance by 2.4 days (IQR: 0.9–4.5 days).

Conclusions

Remdesivir halved viral production, leading to a median reduction of 0.7 days in the time to viral clearance compared with SoC. The efficacy was larger in patients with high viral load at randomization.
Complete pathological response of post neoadjuvant chemotherapy in colorectal cancer with liver metastasis: a case report
Authors: Al Jazzar Ragad I , Algarni Mohammed , Al-Maiman Sarah , Alzahrani Nayef
Published: February 2022

Treatment of metastatic colorectal cancer has evolved throughout the years and various methods have been proposed to reach a pathological complete response state. We report a case of a 73-year-old male presented with a sigmoid adenocarcinoma with two synchronous liver metastases. The patient received five cycles of FOLFOX neoadjuvant chemotherapy, 41% reduction of tumor size was noted upon reassessment. Therefore, a low anterior resection of the rectum and synchronous resection of segment 5 and 8 of the liver was done along with right-sided diaphragmatic stripping. A pathological complete response was achieved in both primary and secondary tumors that are considered rare and challenging in metastatic colorectal cancer. Neoadjuvant chemotherapy showed promising findings in advanced colorectal cancer.
Pair loading in compact sources
Authors: Done C , Ghisellini G , Fabian A C
Published: February 2022

We investigate the effects of a re-acceleration mechanism in compact sources where electron-positron pair production is important. The pairs increase the number of particles to be accelerated and decrease the mean particle energy if the source luminosity remains constant. The acceleration mechanism is loaded. Models in which this effect is included reproduce the γ-ray break seen in active galactic nuclei. It is mainly due to the reduced particle energy and not to photon-photon absorption. The X-ray spectra are generally flatter than those observed if the electrons are accelerated to a single energy. Pair reradiation no longer steepens the spectrum, since loading enhances the importance of the primary emission spectrum. Spectra in agreement with observations can be obtained if the electrons are re-accelerated with a power-law energy distribution.

Our investigation highlights the accumulation of cooled particles within the source. It is a severe constraint on continuous injection models. The lack of any obvious spectral break attributable to Compton downscattering in the high-energy spectra of active galactic nuclei conflicts with the predictions of most models. Highly compact sources produce large amounts of pairs and so have a high optical depth of cooled electrons. We consider this ‘dead electron’ problem for a wide range of models. Reacceleration of the electrons, which is often invoked as a means of overcoming the problem, is not an adequate solution in most cases.
Possible assignment of the 11.3-μm UIR feature to emission from carbonaceous microparticles with internal hydrogens
Authors: Balm S P , Kroto H W
Published: February 2022

The carriers of the UIR bands seen in many galactic and extragalactic objects have previously been assigned to emission from polycyclic aromatic hydrocarbons (PAHs). However, the match between laboratory spectra of typical PAHs with the interstellar features in the structurally sensitive 11-15-μm (909-667-cm-1) region remains unsatisfactory. In particular, it has been difficult to explain, considering that a PAH mixture is undoubtedly involved, why only one strong band is seen at 11.3 μm (885 cm-1) and why this has the same position in all sources. We discuss here the possibility that a hitherto unrecognized class of molecule containing a novel type of hydrogen functional group, the internal hydrogen, may provide important new clues to the origin of the 11.3-μm (885 cm-1) feature. This type of grouping is typified by the molecule kekulene which contains six such internal hydrogens and exhibits bands in its IR absorption spectrum which coincide with the interstellar feature. This structural unit is likely to be common in soot-like microparticles which simulations suggest are present in the cool carbon-rich outflows of red giant stars and hence should contribute to the 11.3-μm (885-cm-1) emission.
The Sérsic-Pastoriza galaxy NGC 1808 - 1 . Radio-continuum, optical and H I observations
Authors: Saikia D J , Unger S W , Pedlar A , Yates G J , Axon D J , Wolstencroft R D , Taylor K , Gyldenkerne K
Published: February 2022

We present radio-continuum observations made at high angular resolution with the VIA at 20, 6 and 2 cm of the central region of the Sersic-Pastoriza galaxy NGC 1808. These observations reveal a population of compact radio sources, reminiscent of those found in the archetypal starburst galaxies M82 and NGC 253. The bulk of these compact features are not coincident with the optical hot-spots and are likely to be individual or unresolved groups of SNRs. We have also made H i observations of NGC 1808 with the VLA (very large array). Although this was primarily to search for unusual motions which may enable us to understand the nuclear activity, we also obtained information on the large-scale distribution and dynamics of gas in this system. The neutral hydrogen is largely concentrated in a central bar, with weak emission from the spiral arms. An absorption profile against the radio emission from the nuclear region shows two features straddling the systemic velocity. The velocity field of the galaxy is largely consistent with rotation although there is evidence of significant non-circular motions in the bar. We discuss any possible relationship between these non-circular motions and the starburst/nuclear activity in the central region of NGC 1808.
Non-locality of the turbulent electromotive force
Authors: Bendre Abhijit B , Subramanian Kandaswamy
Published: February 2022

The generation of large-scale magnetic fields ($\overline{\boldsymbol {B}}$) in astrophysical systems is driven by the mean turbulent electromotive force ($\overline{\rm{\boldsymbol {\cal E}} {}}$), the cross-correlation between local fluctuations of velocity and magnetic fields. This can depend non-locally on $\overline{\boldsymbol {B}}$ through a convolution kernel Kij. In a new approach to find Kij, we directly fit the time-series data of $\overline{\rm{\boldsymbol {\cal E}} {}}$ versus $\overline{\boldsymbol {B}}$ from a galactic dynamo simulation using singular value decomposition. We calculate the usual turbulent transport coefficients as moments of Kij, and show the importance of including non-locality over eddy length-scales to fully capture their amplitudes and that higher order corrections to the standard transport coefficients are small in this case.
A pixelated approach to galaxy catalogue incompleteness: improving the dark siren measurement of the Hubble constant
Authors: Gray R , Messenger C , Veitch J
Published: February 2022

The use of gravitational wave standard sirens for cosmological analyses is becoming well known, with particular interest in measuring the Hubble constant, H0, and in shedding light on the current tension between early- and late-time measurements. The current tension is over 4σ and standard sirens will be able to provide a completely independent measurement. Dark sirens (binary black hole or neutron star mergers with no electromagnetic counterparts) can be informative if the missing redshift information is provided through the use of galaxy catalogues to identify potential host galaxies of the merger. However, galaxy catalogue incompleteness affects this analysis, and accurate modelling of it is essential for obtaining an unbiased measurement of H0. Previously most methods have assumed uniform completeness within the sky area of a gravitational wave event. This paper presents an updated methodology in which the completeness of the galaxy catalogue is estimated in a directionally dependent matter, by pixelating the sky and computing the completeness of the galaxy catalogue along each line of sight. The H0 inference for a single event is carried out on a pixel-by-pixel basis, and the pixels are combined for the final result. A reanalysis of the events in the first gravitational wave transient catalogue leads to an improvement on the measured value of H0 of approximately 5 per cent compared to the 68.3 per cent highest density interval of the equivalent LIGO and Virgo result, with H0 = $68.8^{+15.9}_{-7.8}$ km s−1 Mpc−1.
Magnetic fields in the formation of the first stars – II. Results
Authors: Stacy Athena , McKee Christopher F , Lee Aaron T , Klein Richard I , Li Pak Shing
Published: February 2022

Beginning with cosmological initial conditions at z = 100, we simulate the effects of magnetic fields on the formation of Population III stars and compare our results with the predictions of Paper I. We use gadget-2 to follow the evolution of the system while the field is weak. We introduce a new method for treating kinematic fields by tracking the evolution of the deformation tensor. The growth rate in this stage of the simulation is lower than expected for diffuse astrophysical plasmas, which have a very low resistivity (high magnetic Prandtl number); we attribute this to the large numerical resistivity in simulations, corresponding to a magnetic Prandtl number of order unity. When the magnetic field begins to be dynamically significant in the core of the minihalo at z = 27, we map it on to a uniform grid and follow the evolution in an adaptive mesh refinement, MHD simulation in orion2. The non-linear evolution of the field in the orion2 simulation violates flux-freezing and is consistent with the theory proposed by Xu & Lazarian. The fields approach equipartition with kinetic energy at densities ∼1010–1012 cm−3. When the same calculation is carried out in orion2 with no magnetic fields, several protostars form, ranging in mass from ∼1 to 30 M⊙; with magnetic fields, only a single ∼30 M⊙ protostar forms by the end of the simulation. Magnetic fields thus suppress the formation of low-mass Pop III stars, yielding a top-heavy Pop III initial mass function and contributing to the absence of observed Pop III stars.
rave: a non-parametric method for recovering the surface brightness and height profiles of edge-on debris discs
Authors: Han Yinuo , Wyatt Mark C , Matrà Luca
Published: February 2022

Extrasolar analogues of the Solar System’s Kuiper belt offer unique constraints on outer planetary system architecture. Radial features such as the sharpness of disc edges and substructures such as gaps may be indicative of embedded planets within a disc. Vertically, the height of a disc can constrain the mass of embedded bodies. Edge-on debris discs offer a unique opportunity to simultaneously access the radial and vertical distribution of material; however, recovering either distribution in an unbiased way is challenging. In this study, we present a non-parametric method to recover the surface brightness profile (face-on surface brightness as a function of radius) and height profile (scale height as a function of radius) of azimuthally symmetric, edge-on debris discs. The method is primarily designed for observations at thermal emission wavelengths, but is also applicable to scattered light observations under the assumption of isotropic scattering. By removing assumptions on underlying functional forms, this algorithm provides more realistic constraints on disc structures. We also apply this technique to Atacama Large Millimeter/submillimeter Array observations of the AU Mic debris disc and derive a surface brightness profile consistent with estimates from parametric approaches, but with a more realistic range of possible models that is independent of parametrization assumptions. Our results are consistent with a uniform scale height of 0.8 au, but a scale height that increases linearly with radius is also possible.
Study of UV bright sources in globular cluster NGC 4590 using Ultraviolet Imaging Telescope (UVIT) observations
Authors: Kumar Ranjan , Pradhan Ananta C , Parthasarathy M , Piridi Sonika , Cassisi Santi , Ojha Devendra K , Mohapatra Abhisek , Murthy Jayant
Published: February 2022

We have studied ultraviolet (UV) bright sources in the Galactic globular cluster (GGC) NGC 4590 using Ultraviolet Imaging Telescope onboard the AstroSat satellite. Using UV-optical colour–magnitude diagrams (CMDs), we have identified and characterized the sources of different evolutionary stages i.e. blue horizontal branch stars (BHBs), extremely blue horizontal branch stars (EHBs), blue straggler stars (BSs), variable stars, etc. We estimated effective temperature (Teff), gravity (log (g)), luminosity (Lbol), and hence the radius (R) of these hot stars by fitting spectral energy distribution with the help of stellar atmosphere models. Two new far-UV bright cluster member stars situated near the core of the cluster have been detected; one of them is an EHB star and the other one is either in its post-blue hook evolutionary phase or in white dwarf phase. The evolutionary status of all the hot stars, identified in the cluster, has been investigated by using various evolutionary models. We find the massive and younger BSs are concentrated at the centre of the cluster whereas the older and less massive BSs are distributed throughout the cluster. The BSs normalized radial distribution seems to be bi-modal with a minimum located at rmin = 4.3 rc. We calculated A+ parameter of the cluster which is obtained using cumulative normalized radial distribution of horizontal branch stars (HBs) and BSs. We measured this value up to half-mass radius of the cluster to be +0.13, which indicates that NGC 4590 is one of the youngest clusters among dynamically intermediate age GGCs with a dynamical age of 0.423 ± 0.096 Gyr.