bluuebunny/crossref_metadata_2025 huggingface dataset:
Beam profile and pulse width assessment in an engineered D-shaped hollow-core photonic crystal fiber
Authors: Saeedizadeh Reza , Sabouri Saeed Ghavami , Khorsandi Alireza
Published: October 2021

In this work, a theoretical model is discussed to investigate the performance of a core-engineered gas-filled hollow-core photonic crystal fiber (HC-PCF). To gain the shortest pulse width and the best beam quality at the output, the core geometry of the fiber is modified within four specific types referred to as type I to type IV fibers. It is found that, by using type III and type IV HC-PCF devices, a 5 ps laser pulse in the input can be respectively compressed to 18.5 fs and 13.7 fs at the output. It is found
that, a 5-ps laser pulse in the input can be reduced to 18.5 fs and 13.7 fs if type III- and type IV of modified HC-PCF device are respectively used for compression. The structural similarity (SSIM) index is used to evaluate the quality of the beam cross-section that ultimately emerges from the end of the fiber. The results suggest that the highest SSIM value of 0.76 can be obtained if type III HC-PCF is employed for pulse compression.
Mechanical, metallurgical and tribological properties of friction stir processed aluminium alloy 6061 hybrid surface composites
Authors: AnandhaKumar C J , S Gopi , Kumar S Shashi , Mohan Dhanesh G
Published: October 2021

Friction stir processing (FSP) was applied in the fabrication of aluminium hybrid surface composites by embedding reinforcement particles namely, aluminium oxide (Al2O3), boron nitride (BN) and Graphite (Gr) with Boron carbide (B4C) in an equal volume basis. Three FSPed plates were fabricated at constant tool rotational speed of 1000 rpm, welding speed of 30 mm min−1 and axial force of 6 kN. The microstructure showed the homogeneous dispersion of reinforcement particles and good interfacial bonding between the reinforcement particles and the base material was observed in the processed zone. In terms of strength and hardness, surface composites with B4C and Al2O3 combinations yielded better mechanical properties over other the combinations. The results of wear studies reveal that the FSPed surfaces exhibited better resistance to wear when compared to the base material in a dry sliding condition. The dominance of abrasive wear was observed in all cases of the surface composites inspite of few micro cracks and delamination found on the worn surface. XRD analysis suggests that no secondary phases or intermetallic was formed anywhere in the processed zone.
The influence of thermo-mechanical treatment on phase transformation and shape memory effect of CuAl9Fe4Ni2 alloy
Authors: Khanh Pham Mai , Tuan Vu Anh , Nhung Le Thi , Nam Nguyen Duong
Published: October 2021

Shape memory alloys can return to their original shape by reversible martensitic transformation. The shape memory effect of these alloys has been considered to relate to phase transformation, especially martensite transformation. In the copper-aluminum alloys containing Fe and Ni additives, the relationship between the martensitic transformation and shape memory effect occurs by applying a thermo-mechanical deformation and heat treatment process. This paper presents the phase transformation of the CuAl9Fe4Ni2 alloy that suffered from the deformation and heat treatment process. The samples were heated above 1173°K for homogenization. Then, they were rolled with an appropriate degree of strain to prepare the good conditions for the next steps. They were heated again to 1173°K, then quenched in water to 373°K, and then cooling down in cold water to form martensites with fine grain sizes. Next, the samples underwent cold deformation to create a fine grain in the structure and a favorable distribution for the shape memory process. Finally, the samples were shaped and heated at 843°K to decompose the martensite phase and return to their original shape. The phase transformation and the structure of martensite were determined by modern analytical techniques. The results show that the shape memory level was up to 80%.
Radiation-induced airway changes and downstream ventilation decline in a swine model
Authors: Wallat Eric M , Wuschner Antonia E , Flakus Mattison J , Christensen Gary E , Reinhardt Joseph M , Shanmuganayagam Dhanansayan , Bayouth John E
Published: October 2021

Purpose.To investigate indirect radiation-induced changes in airways as precursors to atelectasis post radiation therapy (RT).Methods.Three Wisconsin Miniature Swine (WMSTM) underwent a research course of 60 Gy in 5 fractions delivered to a targeted airway/vessel in the inferior left lung. The right lung received a max point dose <5 Gy. Airway segmentation was performed on the pre- and three months post-RT maximum inhale phase of the four-dimensional (4D) computed tomography (CT) scans. Changes in luminal area (Ai) and square root of wall area (WA
) for each airway were investigated. Changes in ventilation were assessed using the Jacobian ratio and were measured in three different regions: the inferior left lung <5 Gy (ILL), the superior left lung <5 Gy (SLL), and the contralateral right lung <5 Gy (RL).Results.Airways (n = 25) in the right lung for all swine showed no significant changes (p = 0.48) in Ai post-RT compared to pre-RT. Airways (n = 28) in the left lung of all swine were found to have a significant decrease (p < 0.001) in Ai post-RT compared to pre-RT, correlated (Pearson R = −0.97) with airway dose. Additionally,WA
decreased significantly (p < 0.001) with airway dose. Lastly, the Jacobian ratio of the ILL (0.883) was lower than that of the SLL (0.932) and the RL (0.955).Conclusions.This work shows that for the swine analyzed, there were significant correlations between Ai andWA
change with radiation dose. Additionally, there was a decrease in lung function in the regions of the lung supplied by the irradiated airways compared to the regions supplied by unirradiated airways. These results support the hypothesis that airway dose should be considered during treatment planning in order to potentially preserve functional lung and reduce lung toxicities.
Protein phosphatase 2A (PP2A) promotes anaphase entry after DNA replication stress in budding yeast
Authors: Haluska Cory , Jin Fengzhi , Wang Yanchang
Published: October 2021

A pathway required for the efficient recovery from DNA replication stress in budding yeast was uncovered. During this recovery, PP2A promotes the sequential reversal of Cdk1 phosphorylation by Swe1 and Pds1 phosphorylation by Chk1, which results in the degradation of anaphase inhibitor Pds1 and anaphase entry.
Loss of major nutrient sensing and signaling pathways suppresses starvation lethality in electron transport chain mutants
Authors: Lewis Alisha G. , Caldwell Robert , Rogers Jason V. , Ingaramo Maria , Wang Rebecca Y. , Soifer Ilya , Hendrickson David G. , McIsaac R. Scott , Botstein David , Gibney Patrick A.
Published: October 2021

Electron transport chain starvation lethality is suppressed by disrupting major nutrient sensing and signaling pathways, highlighting uncharacterized signaling roles for the electron transport chain.
Oxford Dictionary of Word Origins
Authors: Cresswell Julia
Published: October 2021

Over 3,000 entries

Newly updated to incorporate recent additions to the English language, this popular dictionary provides a fascinating exploration of the origins and development of words in the English language. Drawing on Oxford's unrivalled dictionary research programme and language monitoring it brings to light the intriguing and often unusual stories of some of our most used words and phrases.

The A-Z entries include the first known use of the term along with examples, related lexes, and expressions which uncover the etymological composition of each word. Also featured are 22 expanded entries that give overviews of broad topic areas, 5 of which are completely new and that variously cover words from Oceania, word blends, eponyms, and acronyms. New findings in the OED since the previous edition have also been added including emoji, mansplain, meeple, meme, and spam.

An absorbing resource for language students and enthusiasts, but also an intriguing read for any person interested in the development of the English language, and of language development in general. It also includes an extended introduction on the history of the English language.
Elsewhere Catastrophe
Authors: Brickhouse Anna
Published: October 2021

This essay explores the problem of what I call “elsewhere catastrophe”: a conviction that catastrophe always occurs outside the US nation, traditionally to the south and the east, or happens to racialized bodies that themselves constitute a kind of beyond. At the same time, American literary history reminds us that the vast knowledge traditions developed by those who faced and still face the structures of ongoing settler colonialism and slavery may provide the best available answers, the strongest critical traction, for facing this century. The project of American literary catastrophism derives in part from a body of theory that Caribbean intellectual history has been developing and refining since the first invasion of the archipelago—and the practice of American literary catastrophism must embrace the many traditions that tell stories, create verse, and generate knowledge about how to live in the midst of world-ending. Through brief readings of Tommy Orange, Herman Melville, and N. K. Jemisin, I propose American literary catastrophism as the project of assembling a broad literary tradition of the hemisphere required of our times.

The project of American literary catastrophism . . . is both historicist and deliberately presentist; it moves between both modes . . . attending to an ongoing catastrophe that always recedes, eventually, from dominant public view and memory.
Spatial variation in bidirectional pollinator-mediated interactions between two co-flowering species in serpentine plant communities
Authors: Stanley Aiden M. , Martel Carlos , Arceo-Gómez Gerardo
Published: October 2021

Pollinator-mediated competition and facilitation are two important mechanisms mediating co-flowering community assembly. Experimental studies, however, have mostly focused on evaluating outcomes for a single interacting partner at a single location. Studies that evaluate spatial variation in the bidirectional effects between co-flowering species are necessary if we aim to advance our understanding of the processes that mediate species coexistence in diverse co-flowering communities. Here, we examine geographic variation (i.e. at landscape level) in bidirectional pollinator-mediated effects between co-flowering Mimulus guttatus and Delphinium uliginosum. We evaluated effects on pollen transfer dynamics (conspecific and heterospecific pollen deposition) and plant reproductive success. We found evidence of asymmetrical effects (one species is disrupted and the other one is facilitated) but the effects were highly dependent on geographical location. Furthermore, effects on pollen transfer dynamics did not always translate to effects on overall plant reproductive success (i.e. pollen tube growth) highlighting the importance of evaluating effects at multiple stages of the pollination process. Overall, our results provide evidence of a spatial mosaic of pollinator-mediated interactions between co-flowering species and suggest that community assembly processes could result from competition and facilitation acting simultaneously. Our study highlights the importance of experimental studies that evaluate the prevalence of competitive and facilitative interactions in the field, and that expand across a wide geographical context, in order to more fully understand the mechanisms that shape plant communities in nature.
The pains of police custody for children: a recipe for injustice and exclusion?
Authors: Bevan Miranda
Published: October 2021

This article utilizes the sociology of punishment, particularly the work of Gresham Sykes in 1958, to develop an understanding of the particular pains of police custody for children, drawing on the first comprehensive study in England and Wales to review the police custody process as a whole from the perspective of the child suspect. By identifying the correspondences and contrasts between the experience of adult sentenced prisoners and child suspects in detention, the analysis illuminates the damaging ramifications of harsh custody processes for children, both in terms of their effective participation in the justice process and their ongoing attitudes towards the police.
Combination therapy of thiamine, vitamin C and hydrocortisone in treating patients with sepsis and septic shock: a meta-analysis and trial sequential analysis
Authors: Yao Renqi , Zhu Yibing , Yu Yue , Li Zhixuan , Wang Lixue , Zheng Liyu , Li Jingyan , Huang Huibin , Wu Guosheng , Zhu Feng , Xia Zhaofan , Ren Chao , Yao Yongming
Published: October 2021

Background

The objective of this study was to evaluate the clinical efficacy of thiamine and vitamin C with or without hydrocortisone coadministration on the treatment of sepsis and septic shock.

Methods

MEDLINE, EMBASE and CENTRAL databases were searched for randomized controlled trials (RCTs) that made a comparative study between the combination therapy of vitamin C and thiamine with or without hydrocortisone and the administration of placebo in patients with sepsis or septic shock. Two reviewers independently performed study selection, data extraction and quality assessment. Both short-term mortality and change in the sequential organ failure assessment (SOFA) score from baseline (delta SOFA) were set as the primary outcomes. Secondary endpoints included intensive care unit (ICU) mortality, new onset of acute kidney injury, total adverse events, ICU and hospital length of stay, duration of vasopressor usage and ventilator-free days. Meanwhile, trial sequential analysis was conducted for primary outcomes.

Results

Eight RCTs with 1428 patients were included in the current study. The results showed no significant reduction of short-term mortality in sepsis and septic shock patients who received combination therapy of vitamin C and thiamine with or without hydrocortisone compared to those with placebo {risk ratio (RR), 1.02 [95% confidence interval (CI), 0.87 to 1.20], p = 0.81, I2 = 0%; risk difference (RD), 0 [95% CI, −0.04 to 0.05]}. Nevertheless, the combination therapy was associated with significant reduction in SOFA score [mean difference (MD), −0.63, (95% CI, −0.96 to −0.29, p < 0.001, I2 = 0%] and vasopressors duration (MD, −22.11 [95% CI, −30.46 to −13.77], p < 0.001, I2 = 6%). Additionally, there were no statistical differences in the pooled estimate for other outcomes.

Conclusions

In the current meta-analysis, the combination therapy of vitamin C and thiamine, with or without hydrocortisone had no impact on short-term mortality when compared with placebo, but was associated with significant reduction in SOFA score among patients with sepsis and septic shock.
Sinus bradycardia as the initial manifestation of multisystem inflammatory syndrome in children
Authors: Gonzalez K , Mendoza Britto I , Mateu M , Marcano E , De Izaguirre J , Sonshire F , Falcon D , Cardenas A , Ortega R , Morr I , Mendoza Mujica I
Published: October 2021

Background

While cardiovascular complications, including arrhythmias are now a recognized manifestation of Multisystem inflammatory syndrome in children (MIS-C), there are no reports of primary bradycardia preceding the clinical presentation. We sought to describe a case series of sinus bradycardia as an initial manifestation of MIS-C.

Methods

We included a series of 10 consecutive patients with confirmed COVID-19 who met WHO and CDC criteria for MIS-C, who developed sinus bradycardia with a heart rate measured in the awake state that was below the normal range for age for children, as an initial manifestation of the disease, in a prospective observational multicenter study. Patients underwent clinical, laboratory evaluation, ECG, Holter, telemetry, echocardiogram, chest X Ray, and a chest CT scan.

Results

Of the 10 patients included, 6 were male, with a mean age of 6.52±5.35 years, range 4 months to 14 years. All cases were Hispanic. Bradycardia was transient and did not merit treatment. Coronary abnormalities were noted in 6 cases; 4 patients had mild coronary ectasia; 9 patients had pericardial effusion with no evidence of tamponade. All patients had a mild clinical course; none had shock, heart failure, the need for mechanical ventilation, or died. All blood markers (Troponin, BNP, Platelet count, C-reactive protein, D-dimer, Ferritin) returned to normal levels by discharge/follow-up with a favorable outcome including resolution of coronary dilatation in all but 2 in which aneurysm persisted.

Treatment

All patients received steroids and low-weight-molecular heparin 10 patients, 8 aspirin and 8 intravenous immunoglobulins.

Conclusion

Sinus bradycardia may be the initial manifestation of MIS-C, usually transient and mild. Physicians should be aware of this presentation.

Funding Acknowledgement

Type of funding sources: None. Kid, MIS-C. Bradycardia/Atrial Rhythm
Coronary calcification by computed tomography in patients with paroxysmal and persistent atrial fibrillation undergoing catheter ablation
Authors: Fernandes S , Ladeiras-Lopes R , Faria R , Ferreira W , Carvalho M , Almeida J , Fonseca P , Oliveira M , Goncalves H , Ferreira N , Primo J , Fontes-Carvalho R
Published: October 2021

Introduction

Cardiac computed tomography (CCT) is routinely performed for pulmonary vein isolation (PVI) planning in patients with paroxysmal or persistent atrial fibrillation (AF). This imaging method can also identify coronary artery calcium (CAC).

Purpose

To evaluate the prevalence of CAC in patients with paroxysmal and persistent AF undergoing catheter ablation.

Methods

Cross-sectional study including patients with AF/atrial flutter (AFL) undergoing CCT for ablation procedure planning from 2017 to 2019. Baseline clinical and demographic data were collected and CAC score was assessed using the Agatston method. Patients with paroxysmal and persistent AF/AFL (defined according to 2020 European Society of Cardiology guidelines for the diagnosis and management of AF) were compared.

Results

A total of 474 patients were included (441 with AF and 33 with AFL), with a mean age of 57±12 years, of which 295 (62%) were males. CHA2DS2-VASc score was ≥1 (male) or ≥2 (female) in 278 (64%) patients and most patients had a low to moderate cardiovascular risk (259, 80%). CAC was identified in 254 (54%) patients. AF/AFL was paroxysmal in 348 (75%) patients and persistent in 116 (25%). Baseline characteristics and cardiovascular risk factors were similar between groups except for diabetes mellitus (33 [10%] vs 22 [20%], p=0.012) and valvular heart disease (13 [4%] vs 18 [16%], p<0.001) that were more prevalent in patients with persistent AF/AFL. Patients with persistent AF/AFL had higher left atrial volume and left ventricle mass (36±8 vs 43±12 ml/m2, p<0.001 and 90±22 vs 96±22 g/m2, p=0.041). CAC was more frequently present in patients with persistent AF/AFL (175 [50%] vs 72 [62%], p=0.028), especially CAC score >100 (58 [17%] vs 35 [30%], p=0.002). After multivariate analysis, CAC score>100 remained an independent predictor of persistent AF/AFL (OR 2.12, 95% CI 1.18–3.82, p=0.013) along with higher left atrial volume (OR 1.06, 95% CI 1.03–1.08, p<0.001).

Conclusion

In this study, coronary artery calcium was present in more than half of AF/FLA patients undergoing catheter ablation. Patients with persistent AF/AFL showed higher calcium scores and this could derive from chronic, more advanced disease. Especially in those patients, opportunistic CV risk screening and CAC-guided clinical management might be clinically useful.

Funding Acknowledgement

Type of funding sources: None.
Myocardial injury in stress echocardiography: comparison of dobutamine, dipyridamole and dynamic stress echocardiography – single centre study
Authors: Medilek K , Stasek J , Zaloudkova L , Pudil R , Cermakova E
Published: October 2021

Background

Stress echocardiography (SE) plays important role in investigation of the patients with chest pain. Adverse events rate is higher in dobutamine stress echocardiography on comparison to dobutamine stress echocardiography (ExSE) or dipyridamole stress echocardiography (DIP). Dynamic stress (ExSE) is recommended as the first-choice method according to the current guidelines.

Purpose

Response to the different stressors was studied in several studies with controversial results. This study aimed to investigate myocardial injury during stress echocardiography measured by the serum high sensitivity troponin (hsTnT) in a low risk population and whether there is a difference in hsTnT response between various stressors.

Methods

135 patients (DSE n=46, ExsE n=46, Dip n=43) investigated for chest pain with suspicion on angina with negative diagnostic stress echocardiography were enrolled in the study. HsTnT was measured before and at 180 min. after the test was terminated. Patients with baseline elevated hsTnT levels (≥14 pg/ml), impaired LV EF (<50%), regional wall motion abnormalities, previous acute coronary syndrome and/or revascularisation, known epicardial coronary artery stenosis >50%, diabetes, prediabates (fasting glycemia at the day of the test ≥5,6 mmol/l, left ventricle hypertrophy >13 mm, baseline uncontrolled hypertension (BP >160/100 mmHg), estimated systolic pulmonary pressure >45 mmHg, more than moderate valvular disease, and patient who experienced dobutmine side effect (hypotension, atrial fibrillation) were excluded from the study.

Results

HsTnT increased in DSE and ExSE, but not in DIP group [9,4 (1,5–58,6), 1,1 (−0,9–15,7), −0,1 (−1,4–2,1) ng/L, p<0,001]. Similar result was found In DSE and ExSE subgroups without atropine [5,3 (0,4–45,3) vs 1,1 (−1,1–15,7) ng/L, p<0,001]. Adding atropine during SE triggered much greater hsTnT release in DSE [40,1 (3,7–160,3) vs 5,3 (0,4–45,3) ng/L, p<0,001], but not in ExSE group [0,6 (−0,9–22,7) vs 1,1 (−1,1–15,7) ng/L, p=0,786]. Moderate correlation of hsTnT rise with DSE length was observed (r=0,43).

Conclusions

DSE leads to significant myocardial injury multiplied when atropine is used. No injury was observed in DIP and only mild was revealed in ExSE. This finding support ExSE as the preferred stress echocardiography method. Whether significant myocardial injury is causative of the higher adverse event rates in DSE remains to be determined.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University Hospital Hradec Kralove, Czech RepublicFaculty of Medicine Hradec Kralove, Charles University, Czech Republic hsTnT change 0–180 min. the whole grouphsTnT change 0–180 min. w/wo atropine
Prognostic value of ABCDE stress echocardiography
Authors: Ciampi Q , Zagatina A , Cortigiani L , Wierzbowska-Drabik K , Haberka M , Djordjevic-Dikic A , Boshchenko A , Gaibazzi N , Rigo F , Simova I , Barbieri A , Morrone D , Villari B , Pellikka P , Picano E ,   Stress Echo 2020 study group of the Italian Society of Echocardiography and Cardiovascular Imaging (SIECVI).
Published: October 2021

Background

Stress echocardiography (SE) was recently upgraded to the ABCDE protocol: step A, regional wall motion abnormalities; step B, B-lines; step C, left ventricular contractile reserve; step D, Doppler-based coronary flow velocity reserve in left anterior descending coronary artery; and step E, EKG-based heart rate reserve. Aim: to assess the prognostic value of ABCDE-SE in a prospective, large scale, multicenter, international, effectiveness study.

Methods

From July 2016 to November 2020, we enrolled 3,574 all-comers (age 65±11 years, 2,070 males, 58%; ejection fraction 60±10%) with known or suspected chronic coronary syndromes referred from 13 certified laboratories. All patients underwent ABCDE-SE. The employed stress modality was exercise (n=952, with semi-supine bike, n=887, or treadmill, n=65 with adenosine for step D) or pharmacological stress (n=2,622, with vasodilator, n=2,151; or dobutamine, n=471). SE response ranged from score 0 (all steps normal) to score 5 (all steps abnormal). All-cause death was the only end-point.

Results

Rate of abnormal results was 16% for A, 30% for B, 36% for C, 28% for D and 37% for E step. During a median follow-up of 21 months, 73 deaths occurred. At univariable analysis, predictors of all-cause mortality were step B (hazard ratio, HR: 2.621, 95% Confidence Intervals, CI: 1.654–4.152, p<0.001), step D (HR: 2.578, 95% CI: 1.624–4.093, p<0.001), and step E (HR: 2.955, 95% CI: 1.848–4.725, p<0.001), but not step A (HR: 1.333, 95% CI: 0.731–2.430, p=0.349) and step C (HR1.581, 95% CI: 0.997–2.506, p=0.051). At multivariable analysis, ABCDE-SE was an independent predictor of mortality with score 3 (HR: 3.472, 95% CI: 1.483–8.135, p=0.004), 4 (HR: 4.045, 95% CI: 1.595–10.259, p=0.003) and 5 (HR: 5.678, 95% CI: 2.106–15.313, p=0.001) (Figure). Annual mortality rate ranged from 0.4% person/year for score 0 up to 2.4% person/year for score 5.

Conclusion

ABCDE-SE allows an effective risk stratification of patient global vulnerability.

Funding Acknowledgement

Type of funding sources: None. Survival curves based on ABCDE score
Risk prediction of atrial fibrillation and its complications in the community using high-sensitivity cardiac troponin I: results from the BiomarCaRE Consortium
Authors: Boerschel C.S , Geelhoed B , Niiranen T , Camen S , Donati M.B , Den Ruijterg H.M , Linneberg A , Lochenl M.L , Kuulasmaa K , Blankenberg S , Iacoviello L , Zeller T , Soederberg S , Salomaa V , Schnabel R.B ,   BiomarCaRE
Published: October 2021

Aims

Atrial fibrillation (AF) is becoming increasingly common and is associated with serious complications. Traditional cardiovascular risk factors (CVRF) do not explain all AF cases. Blood-based biomarkers reflecting cardiac injury may help close this gap. High-sensitivity troponin I (hsTnI) has emerged as a potential predictor.

Methods

We investigated the predictive ability of hsTnI for incident AF in 29,227 participants (median age 52.6 years, 51.2% men) across four different European community cohorts of the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) consortium in comparison to CVRF and established biomarkers (high-sensitive C-reactive protein (hsCRP), N-terminal pro B-type natriuretic peptide (NT-proBNP)).

Results

During a median follow-up of 13.8 (lower and upper quartiles 4.5, 21.3) years, 1,509 (5.2%) participants developed AF. Those in the highest fourth of hsTnI values at baseline (≥5.1 ng/L) had a 2.71-fold (95% confidence interval (CI) 2.31, 3.17; P<0.01) risk for developing AF compared to those in the lowest fourth (≤2.1 ng/L). In multivariable-adjusted Cox proportional hazard models no statistically significant association was seen between hsTnI and AF, whereas NT-proBNP (hazard ratio (HR) per two-fold increase in NT-proBNP 1.64; 95% CI 1.56, 1.72; P<0.001) as well as hsCRP (HR ratio per two-fold increase in hsCRP 1.05; 95% CI 1.01, 1.10; P=0.01) were statistically significantly related to incident AF. Inclusion of hsTnI did not improve model discrimination over CVRFs (C-index CVRF 0.7914 vs. C-index CVRF, hsTnI 0.7927; 95% CI −0.0004, 0.0031; P=0.130). Higher hsTnI concentrations were associated with AF complications such as stroke (HR 1.25; 95% CI 1.03, 1.51; P=0.02), heart failure (HR 1.27; 95% CI 1.12, 1.44; P<0.001) and cardiovascular events (HR 1.24; 95% CI 1.08, 1.42; P<0.001) as well as overall mortality (HR 1.15; 95% CI 1.05, 1.25; P<0.001) in those who were diagnosed with AF.

Conclusion

hsTnI as a biomarker of myocardial injury does not improve prediction of AF incidence beyond classical CVRFs. However, it is associated with AF complications and mortality after AF onset probably reflecting underlying subclinical cardiovascular impairment.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union Seventh Framework Programme (FP7/2007-2013
Diagnostic performance of deep learning on 12-leads electrocardiography for recurrence after pulmonary vein isolation in patients with persistent atrial fibrillation
Authors: Shimizu M , Miyazaki H , Cho S , Misu Y , Tateishi R , Yamaguchi M , Yamakami Y , Shimada H , Manno T , Isshiki A , Kimura S , Fujii H , Suzuki M , Nishizaki M , Sasano T
Published: October 2021

Background

Several patients with persistent atrial fibrillation (per-AF) suffer from recurrence after pulmonary vein isolation (PVI). Various methods to predict the recurrence were tried, but deep learning on 12-leads electrocardiography (ECG) after PVI was not studied.

Purpose

To elucidate diagnostic performance of deep learning on 12-leads ECG after PVI in patients with per-AF

Methods

We enrolled consecutive 109 patients with per-AF who underwent PVI (68.8±10.0 years, 83 males) excluding failure cases. We defined recurrence in 3–12 months after PVI. From the ECG just after PVI, five beats of each lead were sampled separately. Deep learning (convolutional neural network on bitmap ECG image) was performed by transfer learning of Inception-Resnet-V2 model. Gradient weighted class activation color mapping (GradCam) was performed to detect convolutional importance in the lead.

Results

Thirty-six patients showed recurrence in the period. Lead II (accuracy 0.701), aVR (0.690) were the top 2 leads of prediction, which showed larger accuracy than statistical accuracies of Non PV foci = SVC (accuracy = 0.541) and left atrial diameter >50mm (0.596). In lead II, GradCam spotlighted strong convolution of latter half of P wave in recurrent case, and former half of P wave and T wave in no-recurrent case.

Conclusions

Deep learning on ECG was a powerful tool to predict recurrence of per-AF after PVI.

Funding Acknowledgement

Type of funding sources: None. Results of deep learningResults of GradCam
Association between myocardial wall thickness and left ventricular functional recovery after catheter ablation of atrial fibrillation in patients with reduced ejection fraction
Authors: Okada M , Tanaka N , Tanaka K , Hirao Y , Harada S , Onishi T , Koyama Y , Okamura A , Iwakura K , Fujii K , Inoue K
Published: October 2021

Background

Catheter ablation of atrial fibrillation (AFCA) is an effective treatment to develop left ventricular (LV) functional recovery. However, the degree of recovery differs between individuals due to the different extent of myocardial fibrosis and scarring.

Purpose

To examine whether pre-ablation LV wall thickness (WT) and its regional heterogeneity predict LV functional recovery after AFCA in patients with LV systolic dysfunction.

Methods

Of 3682 consecutive patients who underwent first-time AFCA between January 2012 and September 2020 in our institution, 174 (age, 63±10 years; male, 83%; ischemic cardiomyopathy, 14%) with a baseline LV ejection fraction (LVEF) of <40% were retrospectively evaluated. They were subjected to 256-slice MDCT scanning at baseline and 3 months after AFCA. Baseline WT was evaluated by 16-segment model. Mean and standard deviation (SD) of 16 regional WT were calculated in both end-systolic and end-diastolic phase.

Results

LVEF significantly improved from 30±7% to 57±17% (p<0.001) after AFCA. Increase in LVEF (delta-LVEF) was positively correlated with baseline end-diastolic WT (r=0.31, p<0.001) and negatively correlated with SD of end-systolic WT (r=−0.21, p=0.007). Independent of WT measurements, delta-LVEF was negatively correlated with LV end-diastolic volume (r=−0.42, p<0.001). We created a scoring system to predict the degree of wall motion recovery using the median value of the 3 variables; assigned 1 point each for end-diastolic WT >7.4mm, SD of end-systolic WT <1.61mm, and LV end-diastolic volume <125ml. The model successfully predicted improvement in LVEF after AFCA (0 point (N=13) vs. 1 point (N=72) vs. 2–3 point (N=89), 11±16% vs. 20±17% vs. 33±12%, p<0.001).

Conclusion

Myocardial WT and its regional heterogeneity as well as LV end-diastolic volume predicted functional recovery after AFCA in patients with reduced LVEF.

Funding Acknowledgement

Type of funding sources: None.
An off-pump biatrial mini-maze procedure for treatment of long-standing persistent atrial fibrillation
Authors: Yan T , Zhu S.J , Zhu M , Guo C.F
Published: October 2021

Background

Surgical treatment has assumed a more prominent role in the therapy of atrial fibrillation (AF) with favorable efficiency and acceptable safety during the last decades. The traditional Cox-Maze procedure and Wolf Mini-Maze procedure focused on left atrial ablation. However, it is ubiquitous that patients with long-standing persistent atrial fibrillation (LSPAF) typically suffer from biatrial electrical and structural remodeling. The left atrial procedures are still not enough in patients with LSPAF.

Purpose

Herein, we aimed to introduce a modified biatrial off-pump ablation procedure based on the Wolf Mini-Maze procedure and to detect the safety and efficacy of the surgery for patients with LSPAF.

Methods

Between January 2016 and September 2020, 102 patients of LSPAF underwent our modified Mini-Maze procedure using bipolar radiofrequency ablation. Those patients firstly underwent a Mini-Maze procedure using Dallas lesion set, including video-assisted bilateral mini-thoracotomy, left atrial appendage excision, bilateral pulmonary vein isolation, ganglionic plexi evaluation and destruction, left atrial roof connecting lesion, and a linear lesion connecting this roofline to the root of the aorta at the junction of the left coronary and the non-coronary cusp. Secondly, a purse-string suture was performed on the right atrium, and then four ablation lesions were made to the superior vena cava, to the inferior vena cava, to the appendix of the right atrium, and to the tricuspid valve annulus from the purse-string suture point by the bipolar radiofrequency clamp. After the operation, the patients were followed up at an interval of 3, 6, 12 months, and every 1 year after that.

Results

No mortality

No surgical re-exploration for bleeding. No permanent pacemaker implantation. 99 patients were free from LSPAF upon discharge. A follow-up at interval of 3, 6, 12, 24, 36, and 48 months showed a success rate free from LSPAF was 95.1% (97/102), 94.4% (85/90), 94.8% (73/77), 91.5% (54/59), 90.3% (28/31) and 100% (9/9), respectively

Conclusions

The modified biatrial Mini-Maze suggested a safe and feasible procedure. Early follow-up demonstrated an acceptable success rate free from AF. It might have the potential to become another option for clinical treatment of LSPAF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): General Program of the National Natural Science Foundation of China Schematic of the procedure
Anticoagulation and bleeding events in Patients with Post- Operative Atrial Fibrillation After Cardiac Surgery
Authors: Alam Z , Porudominsky R , Lo Presti S , Li V , Rodriguez-Correa C , Glymph D.C , Arenas I
Published: October 2021

Background

Post-operative atrial fibrillation (POPAF) following cardiac surgery is a common arrhythmia associated with an increased morbidity and mortality. There is little data evaluating the safety and effectiveness of anticoagulation (AC) in POPAF patients. We investigated the occurrence of 30-days POP major bleeding or embolic events and their timing in relation to the index cardiac surgery, the initiation of the arrhythmia and of anticoagulation in patients who developed new onset POPAF.

Methods

4,073 consecutive patients undergoing cardiac surgery from September 2010- December 2016 were evaluated. Patients with history of AF/Aflutter were excluded. POPAF was confirmed by ECG or telemetry. Major post-operative bleeding that occurred after AF was defined using PLATO criteria or the BARC scale (any ≥3).

Results

3,230 patients were included (37% CABG, 69% valve surgery). The incidence of POAF was 24%. The median time (IQR) of POPAF was 3 (2) days after the index surgery. 64% of POAF patients were male and 14% had a history of stroke. The mean (SD) age was 72 (9) years old. The average (SD) CHA2DS2-VASc score was 3.9 (1.5). The initial postoperative AC was full dose heparin, lovenox or argatroban in 58% of patients. The rest of patients had low dose heparin/lovenox for DVT prophylaxis and/or were started on oral anticoagulation without a bridge. The median (IR) time of POPAF to anticoagulation was 1 (2) days. There were 15 (1.9%) major bleeding events; 88% of which occurred in patients receiving full anticoagulation. Major bleeding events occurred a median of 15 (9) days after the index surgery and 9 (6) days after anticoagulation. Independent predictors of major bleed were history of PAD (P<0.01) and pre-operative use of b-blockers (P=0.04). There were 11 (1.4%) POP strokes which occurred a median of 5 (16) days after the index surgery, and 2 (13) days after POPAF. 63% of strokes happened in patients that received anticoagulation. The mean CHA2DS2-VASc score were 3.9 (1.5) and 4.7 (1.7), P=0.1 for patients without and with strokes, respectively. Stroke history (P<0.01) was the only independent stroke predictor. Both strokes and bleeding events were associated with significantly longer ICU and hospital length of stay. 86% of POPAF patients received amiodarone during hospitalization and 2.1% electric cardioversion. Upon discharge, 2.3% of patients were in in atrial fibrillation and 0.8% in atrial flutter.

Conclusion

The post-operative course of major bleeds and stroke in patients with POPAF after cardiac surgery is different. Bleeding events are delayed and appear related to anticoagulation. The relative benefit of perioperative anticoagulation remains unclear.

Funding Acknowledgement

Type of funding sources: None.
Association between personalized evidence-based anticoagulation therapy and outcomes at 1-year follow-up in patients with atrial fibrillation: an analysis from the Atrial Fibrillation registry
Authors: Pokushalov E , Losik D , Kozlova S , Konradi A , Sekacheva M , Ponomarenko A , Krivosheev Y , Mikheenko I , Kretov E , Steinberg J.S
Published: October 2021

Background

The guideline treatments based on a relatively broad set of enrollment criteria inhibits the personalized evidence-based approach. Personalized evidence-based medicine (EBM) involves the ability to classify individuals into subpopulations that differ in their susceptibility to a particular disease or their response to a specific treatment.

Objective

We report the 1-year follow-up data of the Atrial Fibrillation Registry, focusing on the relationship between personalized EBM and guideline-adherent anticoagulation therapy use and the occurrence of major clinical adverse events.

Methods

2683 patients at high risk for stroke and 1-year follow-up were enrolled in study. The primary endpoint was the percentage of guideline-based and personalized EBM recommendations acted on by clinicians. Secondary endpoints include the following: outcomes for all-cause mortality, thromboembolism (TE), bleeding, and the composite endpoints.

Results

From 2683 patients, 1971 (73.5%) EMR were guideline adherent and only 824 (30.7%) of them were personalized EBM anticoagulation therapy adherent, whilst 712 (26.5%) were non-guideline adherent and 1147 (42.8%) were guideline adherent but non-personalized EBM adherent.

The composite endpoint of cardiovascular death, any TE or bleeding was significantly lower in personalized EBM adherent patients during 1-year follow-up (P=0.02). The endpoint of all cause death and any TE is increased by >20% by guideline adherent but non-personalized EBM adherent treatment [hazard ratio (HR) 1.254 (95% CI 0.931; 1.689)] and >80% non-guideline adherent and non-personalized EBM adherent treatment [HR 1.892 (95% CI 1.359; 2.635)]. For the composite endpoint of cardiovascular death, any TE or bleeding, guideline adherent but non-personalized EBM adherent treatment increased risk by >40% [HR 1.454 (95% CI 1.037; 2.040)], and non-guideline adherent and non-personalized EBM adherent treatment by >110% [HR 2.113 (95% CI 1.453; 3.074)].

Conclusion

Personalized EBM anticoagulation management is associated with significantly better outcomes, including those related to the composite endpoint of cardiovascular death, any TE or bleeding in high-risk patients.

Funding Acknowledgement

Type of funding sources: None.
Upright exercise stress echocardiography may unmask dynamic left ventricular obstruction also beyond hypertrophic cardiomyopathy
Authors: Cotrim C , Cafe H , Goncalves I , Guardado J , Cotrim N , Cordeiro P , Feliciano J , Baquero L , Picano E
Published: October 2021

Background

Dynamic left ventricular outflow obstruction (LVOTO) during exercise stress echocardiography (ESE) is recommended in hypertrophic cardiomyopathy (HCM) to identify the obstructive phenotype.

Aim

To assess left ventricular outflow gradient (LVOTG) during ESE in different conditions.

Methods

In a single-group, prospective, observational study, we performed peak and/or post-treadmill ESE with systematic assessment of LVOTG in the orthostatic position by continuous-wave Doppler in 1333 subjects (837 males, mean age 38,2±20 ranging from 6 to 87 years) recruited over a period of twenty years, from 2001 to 2021. Peak LVOTG ≥30 mm Hg was considered abnormal for LVOTO during ESE. We enrolled 7 different populations: asymptomatic healthy controls (n=35); HCM (n=81); genotype-positive, phenotype negative asymptomatic HCM (n=6); patients with chest pain symptoms, suspected myocardial ischemia and either normal coronary arteries (INOCA, n=131,or with very low pre-test probability of coronary artery disease (probable INOCA, n=416) and; fatigue and suspected heart failure with preserved ejection fraction (HFpEF, n=206); amateur athletes with ischemia-like ECG changes during exercise-test or symptoms such as near syncope or chest pain or dizziness (n=457); aborted sudden death and with negative screening (n=1).

Results

Technical success rate of LVOTG assessment was 1333/1333 at rest and at peak stress (feasibility 100%). Imaging and analysis time were <1 minute. LVOTG at rest was present in 25 pts (2.8%) of the overall population: 23 HCM, 1 INOCA, and 1 HFpEF. Overall prevalence during ESE was 432/1333 (32%). During ESE, LVOTO (see Figure 1 and 2) was 0% (0/35) in normals, 58% (47/81) in HCM (23 with obstruction at rest), 33% (2/6) in genotype-positive, phenotype negative HCM, 37% (33/131) in INOCA, 40% (135/416) in athletes and 1/1 in the patient with aborted sudden death on strenuous exercise.

Conclusion

LVOTO in orthostatic position is detectable during treadmill ESE in several cardiovascular conditions associated with symptoms such as dyspnea, chest pain or near syncope, and even in asymptomatic patients with genotype-positive, phenotype-negative HCM. The identification of the obstructive phenotype is easy to capture during ESE without any significant additional imaging and analysis burden and can be important also outside HCM.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2
Two-year outcomes of patients with atrial fibrillation treated with rivaroxaban: results from RIVER registry
Authors: Beyer-Westendorf J , Camm A.J , Virdone S , Fox K.A.A , Pieper K.S , Le Heuzey J.-Y , Haas S , Kayani G , Gersh B.J , Turpie A.G.G , Kakkar A.K ,   RIVER Investigators
Published: October 2021

Introduction

Non-vitamin-K oral anticoagulants (NOACs) were recommended in preference to oral vitamin K antagonists (VKAs) in the 2020 updated guidelines for stroke prevention in atrial fibrillation (AF), from the European Society of Cardiology (ESC). Rivaroxaban is a NOAC that is approved in many countries worldwide for reducing the risk of stroke or systemic embolism in patients with nonvalvular atrial fibrillation (AF).

Purpose

To explore the baseline characteristics, dosing and 2-year outcomes of patients with AF treated with rivaroxaban.

Methods

RIVaroxaban Evaluation in Real Life setting (RIVER) is a prospective international, multicenter registry of patients with newly diagnosed non-valvular AF treated with rivaroxaban for the prevention of thromboembolic stroke and at least one investigator-determined risk factor for stroke.

Results

A total of 5043 patients were enrolled into RIVER between January 2015 and June 2017. Mean (SD) age at diagnosis was 69.5 (11.0) years and 55.7% were males. Caucasian patients represented the largest proportion of patients in RIVER (80.3%), followed by Asians (5.5%) and hispanic/latino (3.7%). Almost all patients (98.5%) were prescribed a single daily dose of rivaroxaban, most commonly 20 mg (77.3%) and 15 mg (20.4%), while a 10 mg dose was prescribed in only 2.3% of patients. During the 2-year follow-up, the rates (95% CI) of all-cause mortality, stroke/SE, and major bleeding were 2.75 (2.43 to 3.12), 0.89 (0.72; 1.11), and 1.26 (1.05 to 1.52) per 100 person years, respectively (Figure 1). The most common cardiovascular cause of death was congestive heart failure (30.4%) and myocardial infarction (11.4%). Leading non-cardiovascular causes of death were malignancy (27.4%), respiratory failure (18.9%) and infections/sepsis (13.2%). Over 2 years, 710 (14.1%) of patients discontinued rivaroxaban. The corresponding proportions at 6 months and 1 year were 7.8% and 10.8%, respectively. Out of all the patients who discontinued, 62 (8.7%) restarted rivaroxaban during their follow-up (Table 1).

Conclusion

During 2 years of follow up in the international, prospective RIVER registry, rivaroxaban treatment for AF was associated with low rates of stroke or major bleeding.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by an unrestricted research grant from Bayer AG, Berlin, Germany, to TRI, London, UK. This work is supported by KANTOR CHARITABLE FOUNDATION for the Kantor-Kakkar Global Centre for Thrombosis Science.