Study of High-Transverse-Momentum Higgs Boson Production in Association with a Vector Boson in the qqbb Final State with the ATLAS Detector

This Letter presents the first study of Higgs boson production in association with a vector boson (V=W or Z) in the fully hadronic qqbb final state using data recorded by the ATLAS detector at the LHC in proton-proton collisions at sqrt[s]=13  TeV and corresponding to an integrated luminosity of 137  fb^{-1}. The vector bosons and Higgs bosons are each reconstructed as large-radius jets and tagged using jet substructure techniques. Dedicated tagging algorithms exploiting b-tagging properties are used to identify jets consistent with Higgs bosons decaying into bb[over ¯]. Dominant backgrounds from multijet production are determined directly from the data, and a likelihood fit to the jet mass distribution of Higgs boson candidates is used to extract the number of signal events. The VH production cross section is measured inclusively and differentially in several ranges of Higgs boson transverse momentum: 250-450, 450-650, and greater than 650 GeV. The inclusive signal yield relative to the standard model expectation is observed to be μ=1.4_{-0.9}^{+1.0} and the corresponding cross section is 3.1±1.3(stat)_{-1.4}^{+1.8}(syst)  pb.

Measurement of the Centrality Dependence of the Dijet Yield in p+Pb Collisions at sqrt[s_{NN}]=8.16 TeV with the ATLAS Detector

ATLAS measured the centrality dependence of the dijet yield using 165  nb^{-1} of p+Pb data collected at sqrt[s_{NN}]=8.16  TeV in 2016. The event centrality, which reflects the p+Pb impact parameter, is characterized by the total transverse energy registered in the Pb-going side of the forward calorimeter. The central-to-peripheral ratio of the scaled dijet yields, R_{CP}, is evaluated, and the results are presented as a function of variables that reflect the kinematics of the initial hard parton scattering process. The R_{CP} shows a scaling with the Bjorken x of the parton originating from the proton, x_{p}, while no such trend is observed as a function of x_{Pb}. This analysis provides unique input to understanding the role of small proton spatial configurations in p+Pb collisions by covering parton momentum fractions from the valence region down to x_{p}∼10^{-3} and x_{Pb}∼4×10^{-4}.

Search for New Phenomena in Two-Body Invariant Mass Distributions Using Unsupervised Machine Learning for Anomaly Detection at sqrt[s]=13 TeV with the ATLAS Detector

Searches for new resonances are performed using an unsupervised anomaly-detection technique. Events with at least one electron or muon are selected from 140  fb^{-1} of pp collisions at sqrt[s]=13  TeV recorded by ATLAS at the Large Hadron Collider. The approach involves training an autoencoder on data, and subsequently defining anomalous regions based on the reconstruction loss of the decoder. Studies focus on nine invariant mass spectra that contain pairs of objects consisting of one light jet or b jet and either one lepton (e,μ), photon, or second light jet or b jet in the anomalous regions. No significant deviations from the background hypotheses are observed. Limits on contributions from generic Gaussian signals with various widths of the resonance mass are obtained for nine invariant masses in the anomalous regions.

Observation of WZγ Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter reports the observation of WZγ production and a measurement of its cross section using 140.1±1.2  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. The WZγ production cross section, with both the W and Z bosons decaying leptonically, pp→WZγ→ℓ^{'}^{±}νℓ^{+}ℓ^{-}γ (ℓ^{(^{'})}=e, μ), is measured in a fiducial phase-space region defined such that the leptons and the photon have high transverse momentum and the photon is isolated. The cross section is found to be 2.01±0.30(stat)±0.16(syst)  fb. The corresponding standard model predicted cross section calculated at next-to-leading order in perturbative quantum chromodynamics and at leading order in the electroweak coupling constant is 1.50±0.06  fb. The observed significance of the WZγ signal is 6.3σ, compared with an expected significance of 5.0σ.

Predation risk drives long-term shifts in migratory behaviour and demography in a large herbivore population

Migration is an adaptive life-history strategy across taxa that helps individuals maximise fitness by obtaining forage and avoiding predation risk. The mechanisms driving migratory changes are poorly understood, and links between migratory behaviour, space use, and demographic consequences are rare. Here, we use a nearly 20-year record of individual-based monitoring of a large herbivore, elk (Cervus canadensis) to test hypotheses for changing patterns of migration in and adjacent to a large protected area in Banff National Park (BNP), Canada. We test whether bottom-up (forage quality) or top-down (predation risk) factors explained trends in (i) the proportion of individuals using 5 different migratory tactics, (ii) differences in survival rates of migratory tactics during migration and whilst on summer ranges, (iii) cause-specific mortality by wolves and grizzly bears, and (iv) population abundance. We found dramatic shifts in migration consistent with behavioural plasticity in individual choice of annual migratory routes. Shifts were inconsistent with exposure to the bottom-up benefits of migration. Instead, exposure to landscape gradients in predation risk caused by exploitation outside the protected area drove migratory shifts. Carnivore exploitation outside the protected area led to higher survival rates for female elk remaining resident or migrating outside the protected area. Cause-specific mortality aligned with exposure to predation risk along migratory routes and summer ranges. Wolf predation risk was higher on migratory routes than summer ranges of montane-migrant tactics, but wolf predation risk traded-off with heightened risk from grizzly bears on summer ranges. A novel eastern migrant tactic emerged following a large forest fire that enhanced forage in an area with lower predation risk outside of the protected area. The changes in migratory behaviour translated to population abundance, where abundance of the montane-migratory tactics declined over time. The presence of diverse migratory life histories maintained a higher total population abundance than would have been the case with only one migratory tactic in the population. Our study demonstrates the complex ways in which migratory populations change over time through behavioural plasticity and associated demographic consequences because of individuals balancing predation risk and forage trade-offs.

Combined Measurement of the Higgs Boson Mass from the H→γγ and H→ZZ^{*}→4ℓ Decay Channels with the ATLAS Detector Using sqrt[s]=7, 8, and 13 TeV pp Collision Data

A measurement of the mass of the Higgs boson combining the H→ZZ^{*}→4ℓ and H→γγ decay channels is presented. The result is based on 140  fb^{-1} of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11±0.09(stat)±0.06(syst)=125.11±0.11  GeV. This corresponds to a 0.09% precision achieved on this fundamental parameter of the Standard Model of particle physics.

Search for Dark Photons in Rare Z Boson Decays with the ATLAS Detector

A search for events with a dark photon produced in association with a dark Higgs boson via rare decays of the standard model Z boson is presented, using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider. The dark boson decays into a pair of dark photons, and at least two of the three dark photons must each decay into a pair of electrons or muons, resulting in at least two same-flavor opposite-charge lepton pairs in the final state. The data are found to be consistent with the background prediction, and upper limits are set on the dark photon's coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, α_{D}ϵ^{2}, in the dark photon mass range of [5, 40] GeV except for the ϒ mass window [8.8, 11.1] GeV. This search explores new parameter space not previously excluded by other experiments.

Observation of Single-Top-Quark Production in Association with a Photon Using the ATLAS Detector

This Letter reports the observation of single top quarks produced together with a photon, which directly probes the electroweak coupling of the top quark. The analysis uses 139  fb^{-1} of 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. Requiring a photon with transverse momentum larger than 20 GeV and within the detector acceptance, the fiducial cross section is measured to be 688±23(stat) _{-71}^{+75}(syst)  fb, to be compared with the standard model prediction of 515_{-42}^{+36}  fb at next-to-leading order in QCD.

Measurement of Suppression of Large-Radius Jets and Its Dependence on Substructure in Pb+Pb Collisions at sqrt[s_{NN}]=5.02 TeV with the ATLAS Detector

This letter presents a measurement of the nuclear modification factor of large-radius jets in sqrt[s_{NN}]=5.02  TeV Pb+Pb collisions by the ATLAS experiment. The measurement is performed using 1.72  nb^{-1} and 257  pb^{-1} of Pb+Pb and pp data, respectively. The large-radius jets are reconstructed with the anti-k_{t} algorithm using a radius parameter of R=1.0, by reclustering anti-k_{t} R=0.2 jets, and are measured over the transverse momentum (p_{T}) kinematic range of 158 Collapse

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Measurement of the Sensitivity of Two-Particle Correlations in pp Collisions to the Presence of Hard Scatterings

A key open question in the study of multiparticle production in high-energy pp collisions is the relationship between the "ridge"-i.e., the observed azimuthal correlations between particles in the underlying event that extend over all rapidities-and hard or semihard scattering processes. In particular, it is not known whether jets or their soft fragments are correlated with particles in the underlying event. To address this question, two-particle correlations are measured in pp collisions at sqrt[s]=13  TeV using data collected by the ATLAS experiment at the LHC, with an integrated luminosity of 15.8  pb^{-1}, in two different configurations. In the first case, charged particles associated with jets are excluded from the correlation analysis, while in the second case, correlations are measured between particles within jets and charged particles from the underlying event. Second-order flow coefficients, v_{2}, are presented as a function of event multiplicity and transverse momentum. These measurements show that excluding particles associated with jets does not affect the measured correlations. Moreover, particles associated with jets do not exhibit any significant azimuthal correlations with the underlying event, ruling out hard processes contributing to the ridge.

E-Health intervention for subthreshold depression: Reach and two-year effects of a randomized controlled trial

BACKGROUND

There is evidence for e-Health interventions for full-blown depression. Little is known regarding commonly untreated subthreshold depression in primary care. This randomized controlled multi-centre trial assessed reach and two-year-effects of a proactive e-Health intervention (ActiLife) for patients with subthreshold depression.

METHODS

Primary care and hospital patients were screened for subthreshold depression. Over 6 months, ActiLife participants received three individualized feedback letters and weekly messages promoting self-help strategies against depression, e.g., dealing with unhelpful thoughts or behavioural activation. The primary outcome depressive symptom severity (Patient Health Questionnaire;PHQ-8) and secondary outcomes were assessed 6, 12 and 24 months.

RESULTS

Of those invited, n = 618(49.2 %) agreed to participate. Of them, 456 completed the baseline interview and were randomized to ActiLife (n = 227) or assessment only (n = 226). Generalised estimation equation analyses adjusting for site, setting and baseline depression revealed that depressive symptom severity declined over time, with no significant group differences at 6 (mean difference = 0.47 points; d = 0.12) and 24 months (mean difference = -0.05 points; d = -0.01). Potential adverse effects were observed at 12 months, with higher depressive symptom severity for ActiLife than control participants (mean difference = 1.33 points; d = 0.35). No significant differences in rates of reliable deterioration or reliable improvement of depressive symptoms were observed. ActiLife increased applied self-help strategies at 6 (mean difference = 0.32; d = 0.27) and 24 months (mean difference = 0.22; d = 0.19), but not at 12 months (mean difference = 0.18; d = 0.15).

LIMITATIONS

Self-report measures and lack of information on patients' mental health treatment.

DISCUSSION

ActiLife yielded satisfactory reach and increased the use of self-help strategies. Data were inconclusive in terms of depressive symptom changes.

Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector

A search is made for potential ccc[over ¯]c[over ¯] tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at sqrt[s]=13  TeV, corresponding to an integrated luminosity of 140  fb^{-1} recorded by the ATLAS experiment at LHC. Two decay channels, J/ψ+J/ψ→4μ and J/ψ+ψ(2S)→4μ, are studied. Backgrounds are estimated based on a hybrid approach involving Monte Carlo simulations and data-driven methods. Statistically significant excesses with respect to backgrounds dominated by the single parton scattering are seen in the di-J/ψ channel consistent with a narrow resonance at 6.9 GeV and a broader structure at lower mass. A statistically significant excess is also seen in the J/ψ+ψ(2S) channel. The fitted masses and decay widths of the structures are reported.

Observation of the γγ→ττ Process in Pb+Pb Collisions and Constraints on the τ-Lepton Anomalous Magnetic Moment with the ATLAS Detector

This Letter reports the observation of τ-lepton-pair production in ultraperipheral lead-lead collisions Pb+Pb→Pb(γγ→ττ)Pb and constraints on the τ-lepton anomalous magnetic moment a_{τ}. The dataset corresponds to an integrated luminosity of 1.44  nb^{-1} of LHC Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded by the ATLAS experiment in 2018. Selected events contain one muon from a τ-lepton decay, an electron or charged-particle track(s) from the other τ-lepton decay, little additional central-detector activity, and no forward neutrons. The γγ→ττ process is observed in Pb+Pb collisions with a significance exceeding 5 standard deviations and a signal strength of μ_{ττ}=1.03_{-0.05}^{+0.06} assuming the standard model value for a_{τ}. To measure a_{τ}, a template fit to the muon transverse-momentum distribution from τ-lepton candidates is performed, using a dimuon (γγ→μμ) control sample to constrain systematic uncertainties. The observed 95% confidence-level interval for a_{τ} is -0.057 Collapse

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Strong Constraints on Jet Quenching in Centrality-Dependent p+Pb Collisions at 5.02 TeV from ATLAS

Jet quenching is the process of color-charged partons losing energy via interactions with quark-gluon plasma droplets created in heavy-ion collisions. The collective expansion of such droplets is well described by viscous hydrodynamics. Similar evidence of collectivity is consistently observed in smaller collision systems, including pp and p+Pb collisions. In contrast, while jet quenching is observed in Pb+Pb collisions, no evidence has been found in these small systems to date, raising fundamental questions about the nature of the system created in these collisions. The ATLAS experiment at the Large Hadron Collider has measured the yield of charged hadrons correlated with reconstructed jets in 0.36  nb^{-1} of p+Pb and 3.6  pb^{-1} of pp collisions at 5.02 TeV. The yields of charged hadrons with p_{T}^{ch}>0.5  GeV near and opposite in azimuth to jets with p_{T}^{jet}>30 or 60 GeV, and the ratios of these yields between p+Pb and pp collisions, I_{pPb}, are reported. The collision centrality of p+Pb events is categorized by the energy deposited by forward neutrons from the struck nucleus. The I_{pPb} values are consistent with unity within a few percent for hadrons with p_{T}^{ch}>4  GeV at all centralities. These data provide new, strong constraints that preclude almost any parton energy loss in central p+Pb collisions.

Search for Heavy Neutral Leptons in Decays of W Bosons Using a Dilepton Displaced Vertex in sqrt[s]=13 TeV pp Collisions with the ATLAS Detector

A search for a long-lived, heavy neutral lepton (N) in 139  fb^{-1} of sqrt[s]=13  TeV pp collision data collected by the ATLAS detector at the Large Hadron Collider is reported. The N is produced via W→Nμ or W→Ne and decays into two charged leptons and a neutrino, forming a displaced vertex. The N mass is used to discriminate between signal and background. No signal is observed, and limits are set on the squared mixing parameters of the N with the left-handed neutrino states for the N mass range 3  GeV Collapse

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Test of CP Invariance in Higgs Boson Vector-Boson-Fusion Production Using the H→γγ Channel with the ATLAS Detector

A test of CP invariance in Higgs boson production via vector-boson fusion has been performed in the H→γγ channel using 139  fb^{-1} of proton-proton collision data at sqrt[s]=13  TeV collected by the ATLAS detector at the LHC. The optimal observable method is used to probe the CP structure of interactions between the Higgs boson and electroweak gauge bosons, as described by an effective field theory. No sign of CP violation is observed in the data. Constraints are set on the parameters describing the strength of the CP-odd component in the coupling between the Higgs boson and the electroweak gauge bosons in two effective field theory bases: d[over ˜] in the HISZ basis and c_{HW[over ˜]} in the Warsaw basis. The results presented are the most stringent constraints on CP violation in the coupling between Higgs and weak bosons. The 95% C.L. constraint on d[over ˜] is derived for the first time and the 95% C.L. constraint on c_{HW[over ˜]} has been improved by a factor of 5 compared to the previous measurement.

The KMT2A recombinome of acute leukemias in 2023

Chromosomal rearrangements of the human KMT2A/MLL gene are associated with de novo as well as therapy-induced infant, pediatric, and adult acute leukemias. Here, we present the data obtained from 3401 acute leukemia patients that have been analyzed between 2003 and 2022. Genomic breakpoints within the KMT2A gene and the involved translocation partner genes (TPGs) and KMT2A-partial tandem duplications (PTDs) were determined. Including the published data from the literature, a total of 107 in-frame KMT2A gene fusions have been identified so far. Further 16 rearrangements were out-of-frame fusions, 18 patients had no partner gene fused to 5'-KMT2A, two patients had a 5'-KMT2A deletion, and one ETV6::RUNX1 patient had an KMT2A insertion at the breakpoint. The seven most frequent TPGs and PTDs account for more than 90% of all recombinations of the KMT2A, 37 occur recurrently and 63 were identified so far only once. This study provides a comprehensive analysis of the KMT2A recombinome in acute leukemia patients. Besides the scientific gain of information, genomic breakpoint sequences of these patients were used to monitor minimal residual disease (MRD). Thus, this work may be directly translated from the bench to the bedside of patients and meet the clinical needs to improve patient survival.

The effects of circadian desynchronization on alcohol consumption and affective behavior during alcohol abstinence in female rats

Disruption of circadian rhythmicity distorts physiological and psychological processes and has major consequences on health and well-being. A chronic misalignment within the internal time-keeping system modulates alcohol consumption and contributes to stress-related psychiatric disorders which are known to trigger alcohol misuse and relapse. While there is growing evidence of the deleterious impact of circadian disruption on male physiology and behavior, knowledge about the effect in females remains limited. The present study aims to fill the gap by assessing the relationship between internal desynchronization and alcohol intake behavior in female rats. Female Wistar rats kept under standard 24-h, 22-h light-dark conditions, or chronic 6-h advanced phase shifts, were given intermittent access to 20% alcohol followed by an extended alcohol deprivation period. Alcohol consumption under altered light-dark (LD) conditions was assessed and emotional behavior during alcohol abstinence was evaluated. Internally desynchronization in female rats does not affect alcohol consumption but alters scores of emotionality during alcohol abstinence. Changes in affective-like behaviors were accompanied by reduced body weight gain and estrous irregularities under aberrant LD conditions. Our data suggest that internal desynchronization caused by environmental factors is not a major factor contributing to the onset and progression of alcohol abuse, but highlights the need of maintaining circadian hygiene as a supportive remedy during alcohol rehabilitation.

An epidemiologic retrospective study of maxillofacial traumatology in the elderly

INTRODUCTION

The elderly population, which is more active than before, is increasingly suffering from trauma (loss of reflexes and systemic pathologic conditions). Surgical management may be more controversial due to the potential consequences of general anesthesia and the sometimes negligible consequences of functional management. The main objective of this study was to analyze the causes and location of facial fractures in subjects older than 65 years. The secondary objective was to evaluate the management of these fractures (surgical or functional) according to comorbidities.

MATERIAL & METHODS

In this retrospective study (over a five-year period), we analyzed the causes and management of facial fractures in patients aged over 65 years, and the medical history of each patient was investigated.

RESULTS

One hundred and nineteen patients with 198 facial fractures were included. The main cause of fractures was a fall (50%). The zygomatic region (39.9%) and mandible (27.8%) were the sites of the most frequent fractures. Comorbidities were found in 84.9% of patients, the majority of which were cardiovascular diseases (82.3%). 75.8% of fractures were treated surgically and 4.8% of patients had complications.

DISCUSSION

This work is a help to understanding the causes and consequences of facial trauma in the elderly population. The management of these facial fractures requires a multidisciplinary assessment, taking into account the patient's medical history and evaluating the risks and benefits of a surgical procedure with general anesthesia.

Managing Minds at Work: development of a digital line manager training programme

Background

Mental ill health is the leading cause of sickness absence with high economic burden. Workplace interventions aimed at supporting employers with prevention of mental ill-health in the workforce are urgently required. Managing Minds at Work (MMW) is a digital intervention targeting support for line managers in any work setting to promote better mental health at work through a preventative approach.

Objectives

To describe the design and development of the MMW digital training programme, prior to feasibility testing. We adopted a collaborative participatory design involving co-design (users as partners) and principles of user-centred design (pilot and usability testing). Agile methodology was used to co-create intervention content with a stakeholder community of practice. Development processes were mapped to core elements of the Medical Research Council (MRC) framework for developing and evaluating complex interventions.

Results

The program covers five broad areas: (i) promoting self-care techniques among line managers; (ii) designing work to prevent work-related stress; (iii) management competencies to prevent and reduce stress; (iv) having conversations with employees about mental health; (v) building a psychologically safe work environment. Pilot and usability testing (n = 37 surveys) aligned with the Technology Acceptance Model (TAM) demonstrated that MMW was perceived to be useful, relevant, and easy to use by managers across sectors, organization types and sizes. We identified positive impacts on manager attitudes and behavioural intentions related to preventing mental ill-health and promoting good mental well-being at work.

Conclusions

MMW is a digital training programme for line managers that has been co-created using rigorous development processes and aims to support employers with primary prevention in mental health. The next step is to explore the feasibility and acceptability of this intervention with line managers in diverse employment settings.

Key messages

Peroxynitrite in the tumor microenvironment changes the profile of antigens allowing escape from cancer immunotherapy

Cancer immunotherapy often depends on recognition of peptide epitopes by cytotoxic T lymphocytes (CTLs). The tumor microenvironment (TME) is enriched for peroxynitrite (PNT), a potent oxidant produced by infiltrating myeloid cells and some tumor cells. We demonstrate that PNT alters the profile of MHC class I bound peptides presented on tumor cells. Only CTLs specific for PNT-resistant peptides have a strong antitumor effect in vivo, whereas CTLs specific for PNT-sensitive peptides are not effective. Therapeutic targeting of PNT in mice reduces resistance of tumor cells to CTLs. Melanoma patients with low PNT activity in their tumors demonstrate a better clinical response to immunotherapy than patients with high PNT activity. Our data suggest that intratumoral PNT activity should be considered for the design of neoantigen-based therapy and also may be an important immunotherapeutic target.

Right ventricular ejection fraction assessed by computed tomography in patients undergoing transcatheter tricuspid valve intervention

Background

The role of right-ventricular (RV) function in patients with tricuspid regurgitation (TR) undergoing transcatheter tricuspid valve interventions (TTVI) is poorly understood. Although cardiac computed tomography (CCT) provides elaborate three-dimensional (3D) visualization of the entire anatomy of the RV and theoretically allows to assess the global RV systolic function. Nevertheless, the utility of the functional assessments of the RV using CCT remains unclear in patients undergoing TTVI.

Purpose

This study investigated the association of right-ventricular ejection fraction (RVEF) assessed by CCT with clinical outcome in patients undergoing TTVI.

Methods

We retrospectively assessed 3D-RVEF by using pre-procedural CCT images in patients undergoing TTVI with either edge-to-edge repair or annuloplasty device. RV dysfunction (RVD) was defined as a CT-RVEF <45%. The primary outcome was a composite outcome, consisting of all-cause mortality and hospitalization due to heart failure, within one year after TTVI.

Results

Of 157 patients, 58 (36.9%) presented with CT-RVEF <45%. Patients with CT-RVEF <45% were more likely to be male, to have a previous history of coronary artery disease, and had higher EuroSCORE II and a lower LVEF compared to those with CT-RVEF ≥45%, while the severity of TR was comparable between the groups.

Among the patients with CT-RVEF <45%, acute procedural success was achieved in 93.1%, and in-hospital mortality was 1.7%, which were comparable to those with CT-RVEF ≥45%.

Patients with CT-RVEF <45% had an improvement in New York Heart Association functional class at follow-up compared to baseline; however, CT-RVEF <45% was associated with a higher risk of the composite outcome (adjusted hazard ratio: 3.23; 95% confidence interval: 1.52–6.88; p=0.002) (Figure 1). Furthermore, CT-RVEF had an additional value to stratify the risk of the composite outcome beyond two-dimensional transthoracic echocardiographic (TTE) assessments (Figure 2).

In addition, patients with CT-RVEF <45% exhibited an attenuated association between a reduction in TR to <3+ and a lower incidence of the composite outcome after TTVI compared to those with CT-RVEF ≥45%.

Conclusions

TTVI is safe and feasible regardless of baseline RV function, while RVD, defined as 3D-RVEF <45%, is associated with a higher risk of the composite outcomes within one year after TTVI. Furthermore, our findings suggest that the prognostic benefits of TR reduction might be attenuated in patients with RVD. Given the additional prognostic value of CT-RVEF to the conventional echocardiographic assessments, the assessments of 3D-RVEF with CCT may refine the patient selection for TTVI.

Funding Acknowledgement

Type of funding sources: None.

Intraoperative cone beam assessment after reduction of zygomatic fractures helps in taking a decision on associated orbital floor fractures

INTRODUCTION

Orbital floor fracture (OFF) are frequently associated with zygomatic fractures (ZF). The reduction of the ZF may modify the features of the associated OFF. Intraoperative cone beam CT (CBCT) has shown diagnostic performance of OFF. The aim of our study was to evaluate how intraoperative CBCT control made after the reduction of ZF may help to take a decision on the associated OFF.

MATERIAL AND METHOD

Patients with a unilateral displaced ZF associated with an OFF were consecutively included during a 3-year period. Intraoperative CBCT, systematically performed after reduction of the ZF, allowed to decide if the OFF needed reconstruction. The preoperative estimation made on MDCT and the intraoperative decision regarding the OFF were compared.

RESULTS

Fifty-nine consecutive patients could be included in the study. Nineteen OFF were presumed to be surgical indications on the preoperative MDCT but only 16 indications were confirmed on the intraoperative CBCT, meaning that 3 OFF behaved favorably during the ZF reduction. Forty orbital floor fractures were presumed to be non-surgical on the preoperative MDCT but 6 of them worsened during ZF reduction and became surgical indications. Overall, the intraoperative CBCT control had an impact on 9 (15.3%) of the OFF.

CONCLUSION

Our study showed that OFF after ZF reduction may evolve favorably or, on the contrary, get worse in 15% of the cases. Surgical indication on an OFF can therefore be confirmed intraoperatively. This allows to avoid under-treatment in the patients where the OFF worsens after ZF reduction and over-treatment in the patient where the OFF reduces after ZF.

Dragon 1 Protocol Manuscript: Training, Accreditation, Implementation and Safety Evaluation of Portal and Hepatic Vein Embolization (PVE/HVE) to Accelerate Future Liver Remnant (FLR) Hypertrophy

STUDY PURPOSE

The DRAGON 1 trial aims to assess training, implementation, safety and feasibility of combined portal- and hepatic-vein embolization (PVE/HVE) to accelerate future liver remnant (FLR) hypertrophy in patients with borderline resectable colorectal cancer liver metastases.

METHODS

The DRAGON 1 trial is a worldwide multicenter prospective single arm trial. The primary endpoint is a composite of the safety of PVE/HVE, 90-day mortality, and one year accrual monitoring of each participating center. Secondary endpoints include: feasibility of resection, the used PVE and HVE techniques, FLR-hypertrophy, liver function (subset of centers), overall survival, and disease-free survival. All complications after the PVE/HVE procedure are documented. Liver volumes will be measured at week 1 and if applicable at week 3 and 6 after PVE/HVE and follow-up visits will be held at 1, 3, 6, and 12 months after the resection.

RESULTS

Not applicable.

CONCLUSION

DRAGON 1 is a prospective trial to assess the safety and feasibility of PVE/HVE. Participating study centers will be trained, and procedures standardized using Work Instructions (WI) to prepare for the DRAGON 2 randomized controlled trial. Outcomes should reveal the accrual potential of centers, safety profile of combined PVE/HVE and the effect of FLR-hypertrophy induction by PVE/HVE in patients with CRLM and a small FLR.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04272931 (February 17, 2020). Toestingonline.nl: NL71535.068.19 (September 20, 2019).

Observation of WWW Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter reports the observation of WWW production and a measurement of its cross section using 139  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWW production cross section is measured to be 820±100 (stat)±80 (syst)  fb, approximately 2.6 standard deviations from the predicted cross section of 511±18  fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy.

Spatial correction improves accuracy of catheter positioning during ablation of premature ventricular contractions: differences between ventricular outflow tracts and other localizations

BACKGROUND

Hybrid activation mapping is a novel tool to correct for spatial displacement of the mapping catheter due to asymmetrical contraction of myocardium during premature ventricular contractions (PVC). The aim of this study is to describe and improve our understanding of spatial displacement during PVC mapping as well as options for correction using hybrid activation mapping.

METHODS AND RESULTS

We analyzed 5798 hybrid mapping points in 40 acquired hybrid maps of 22 consecutive patients (age 63 ± 16 years, 45% female) treated for premature ventricular contractions (PVCs). Median PVC-coupling interval was 552 ms (IQR 83 ms). Spatial displacement was determined by measuring the dislocation of the catheter tip during PVC compared to the preceding sinus beat. Mean spatial displacement was 3.8 ± 1.5 mm for all maps. The displacement was 1.3 ± 0.4 mm larger for PVCs with non-outflow-tract origin compared to PVCs originating from the ventricular outflow tracts (RVOT/LVOT; p = 0.045). Demographic parameters, PVC-coupling-interval and chamber of origin had no significant influence on the extent of spatial displacement.

CONCLUSION

Ectopic activation of the ventricular myocardium during PVCs results in spatial displacement of mapping points that is significantly larger for PVCs with non-outflow-tract origin. The correction for spatial displacement may improve accuracy of radiofrequency current (RFC)-application in catheter ablation of PVCs.

Current Evidence on where to End a Fusion within the Thoracolumbar Junction Most Preferably - A Systematic Literature Review

Proximal junctional kyphosis (PJK) is one main complication in the surgical treatment of adult spinal deformities. Ending within the thoracolumbar junction (TLJ) should but cannot always be avoided to reduce the risk for PJK. With this systematic review we sought to define the most preferable vertebra within the TLJ to minimize the risk for PJK and establish recommendations based on our findings. We conducted a systematic literature review by scanning the MEDLINE database in accordance with the PRISMA criteria. All articles addressing primary long-distance dorsal thoracolumbar fusion of at least three segments to treat adult spinal deformities were included. 1385 articles were identified and three were included to this review. The first study showed significantly higher rates of PJK in patients where the construct was extended to T7 or higher when compared to an ending at T11 to L1. The second article stated that an expansion to the TLJ resulted in significantly less surgical revisions due to PJK reduction. On the other hand, the third article found that a fusion of the whole thoracic spine reduces the PJK incidence postoperatively. Even though the most favorable vertebra within the TLJ to avoid PJK best could not yet be determined, our study identifies several principles that represent the current state of evidence for surgical treatment of adult scoliosis. Proper preoperative decision making based on thorough analysis and interpretation of the patient's sagittal alignment parameters can improve the individual outcome critically.

A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery

The standard model of particle physics1-4 describes the known fundamental particles and forces that make up our Universe, with the exception of gravity. One of the central features of the standard model is a field that permeates all of space and interacts with fundamental particles5-9. The quantum excitation of this field, known as the Higgs field, manifests itself as the Higgs boson, the only fundamental particle with no spin. In 2012, a particle with properties consistent with the Higgs boson of the standard model was observed by the ATLAS and CMS experiments at the Large Hadron Collider at CERN10,11. Since then, more than 30 times as many Higgs bosons have been recorded by the ATLAS experiment, enabling much more precise measurements and new tests of the theory. Here, on the basis of this larger dataset, we combine an unprecedented number of production and decay processes of the Higgs boson to scrutinize its interactions with elementary particles. Interactions with gluons, photons, and W and Z bosons-the carriers of the strong, electromagnetic and weak forces-are studied in detail. Interactions with three third-generation matter particles (bottom (b) and top (t) quarks, and tau leptons (τ)) are well measured and indications of interactions with a second-generation particle (muons, μ) are emerging. These tests reveal that the Higgs boson discovered ten years ago is remarkably consistent with the predictions of the theory and provide stringent constraints on many models of new phenomena beyond the standard model.

Characterization of Affective Behaviors and Motor Functions in Mice With a Striatal-Specific Deletion of Bmal1 and Per2

The expression of circadian clock genes, either centrally or in the periphery, has been shown to play an integral role in the control of behavior. Brain region-specific downregulation of clock genes revealed behavioral phenotypes associated with neuropsychiatric disorders and neurodegenerative disease. The specific function of the clock genes as well as the underlying mechanisms that contribute to the observed phenotypes, however, are not yet fully understood. We assessed anxiety- and depressive-like behavior and motor functions in male and female mice with a conditional ablation of Bmal1 or Per2 from medium spiny neurons (MSNs) of the striatum as well as mice lacking one copy of Gpr88. Whereas the conditional knockout of Bmal1 and Per2 had mild effects on affective behaviors, a pronounced effect on motor functions was found in Bmal1 knockout mice. Subsequent investigation revealed an attenuated response of Bmal1 knockout mice to dopamine receptor type 1 agonist treatment, independently of the expression of targets of the dopamine signaling pathway or mitochondrial respiration in MSNs. The study thus suggests a potential interaction of Bmal1 within the direct dopamine signaling pathway, which may provide the link to a shared, MSN-dependent mechanism regulating affective behavior and motor function in mice.

Why are redo AF ablations required and what does it take? Type of index PVI predicts pattern of redo ablations

Funding Acknowledgements

Type of funding sources: None.

Background

Catheter ablation targeting isolation of the pulmonary veins (PVI) is the most effective treatment for atrial fibrillation (AF). Despite its high overall effectiveness, repeat AF ablations (re-do procedures, RDP) are often required to maintain sinus rhythm.

Purpose

Determine predictors for multiple and/or complex RDP, evaluate reference values for procedure duration and radiation exposure during index PVI (iPVI) and nth RDP in a large cohort.

Methods and Results

Data mining identified 934 (mean age 62.6 ± 12.3 years, 346 females) out of 6848 total AF ablation patients from a large German AF ablation center between 09/2008 and 09/2021 with an index PVI and at least one RDP. Analysis included 2152 procedures (out of 8750 total AF-related ablations). At iPVI, AF pattern was classified as paroxysmal AF (PAF) in 387 patients (41%). All others (59%) were classified as non-paroxysmal AF (Non-PAF). Non-PAF was significantly more frequent in males (64% vs. 49%, p<0.01). Median period between first PVI and RDP was 558 days (25th/75th percentiles 244.0/1175.5 days). Non-PAF patients had a significantly higher probability of multiple RDP compared to patients with PAF at iPVI (p<0.01, Figure 1A). 18% (8%) of patients with non-PAF had 2 (3) or more RDP while only 13% (3%) of pat. with PAF had 2 (3) or more RDP.

iPVI was classified as PVI-only or PVI with additional substrate modification (SM). 724/934 patients (78%) received PVI-only as initial procedure. Of these, 572 (79%) had only 1 RDP, 116 (16%) had 2 RDP and 36 (5%) had 3 or more RDP. This distribution was 77%, 15% and 8% for 1, 2 and 3 or more RDP for patients with complex PVI as iPVI.

An algorithm based on regular expressions classified all RDP as repeat PVI (Re-PVI) due to reconduction (PV reconduction), ablation of atrial tachycardia (AT) or SM, e. g. defragmentation of fractionated signals, or combinations. The results were manually quality-controlled. 798/934 (85%) patients required PV re-isolation due to PV reconduction, 298/934 (32%) required ablation for atrial tachycardia (AT) at least once during FU (Figure 1B). Comparing PVI-only iPVI patients with patients who received substrate modification during iPVI, significantly less patients with PVI-only iPVI had RDP for AT compared to those with SM during iPVI (27% vs. 50%, p<0.01). More PVI-only iPVI patients required PV-reisolation at any time during FU (87% vs 79%, p<0.01). Considering PVI-only (+/- CTI) iPVIs only, dose-area product decreased in RDP compared to first PVI, while procedure duration slightly increased (Figure 1C). Data on periprocedural complications will be reported.

Conclusion

Redo AF ablations procedures are mainly required due to reconnected pulmonary veins or AT. Patients with PAF at iPVI are less likely to require more than one RDP which provides indirect support for early rhythm control in treatment of AF. SM at iPVI might be a predictor for occurrence of AT in the further course.

Early recurrences after catheter ablation for atrial tachycardia: do we need a blanking period?

Funding Acknowledgements

Type of funding sources: None.

Background

A blanking period after catheter ablation for atrial fibrillation is widely accepted. The clinical implications of early recurrences (ER) after ablation for atrial tachycardia (AT) in patients with a history of atrial fibrillation have not been analysed so far.

Purpose

To characterise ER and their relationship with late recurrences (LR) after AT ablation.

Methods

Acute and long-term outcome was studied in a total of 250 patients undergoing catheter ablation for consecutive AT. ER were defined as any documented atrial arrhythmia >30 s within 3 months after ablation.

Results

In our study population (66.5±0.7 years, 57.6% male), ER were detected in 80 patients (32.0%), with 74.0% of episodes occurring during the first month post-ablation. Patients with ER had a longer history of any atrial arrhythmia (9.1±0.9 years vs. 6.5±0.4 years; P=0.0283), a larger left atrial diameter (65.7±3.1 mm vs. 49.4±1.4 mm; P=0.0163) and a lower left ventricular ejection fraction (50.8±1.1% vs. 56.6±0.6%; P<0.0001) than those without ER. In patients with ER, AT were more often found to be mitral isthmus-dependent (16.5% vs. 6.2%; P=0.0048) or located at the crista terminalis (3.7% vs. 0.4%; P=0.0343). ER were associated with a 6.0-fold (95% CI 3.27-10.81; P<0.0001) and a 4.3-fold (95% CI 1.72-10.72; P=0.0023) increase in the risk of developing LR after a single or multiple ablation procedures, respectively (Figure). After a mean follow-up of 570±23 days, LR were detected in 78.0% vs. 76.9% vs. 50.0% of patients experiencing the first ER during the first, second or third month (P=0.2266). Among these groups, the first LR occurred after 188.7±20.2 days vs. 259.6±59.1 days vs. 400.8±55.5 days (P=0.0459).

Conclusions

ER after AT ablation are a predictor of LR and clinical as well as procedural risk factors are associated with the occurrence of ER. The prevalence of LR does not differ among patients with early vs. late ER. These findings underline the prognostic importance of ER and challenge the concept of a blanking period after catheter ablation for AT in patients with a history of atrial fibrillation.

Pulmonary vein isolation by pulsed-field ablation induces smaller neurocardiac damage than cryoballoon ablation

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): FARAPULSE, Inc.

Introduction

Thermal energy sources damage the entire atrial tissue during pulmonary vein isolation (PVI) including cardiac nerves and ganglia. This induces a postinterventional increase in heart rate. Pulsed-field ablation (PFA), a new non-thermal energy source for PVI, primarily damages cardiomyocytes by electroporation. Whether use of PFA reduces damage to cardiac nerves and ganglia and influences postinterventional increase of heart rate is not known.

Purpose

We compared the acute effects of PFA with a pentaspline catheter and cryoballoon ablation (CBA) on secretion of circulating biomolecules reflecting cardiomyocyte and neuronal injury and postinterventional increase in heart rate to estimate damage to the cardiac autonomic nervous system and autonomic dysfunction after PVI.

Methods

Blood samples were taken before and after PVI in consecutive patients undergoing PFA and CBA. All patients participated in the TRUST registry. Serum concentrations of high-sensitive Troponin I (hsTropI, Immunoassay) and S100b (ELISA), a surrogate marker for neuronal injury, were quantified in blood samples taken prior to PVI and directly after PVI. Pre- and postinterventional heart rates were measured in ECGs and Holter-ECGs.

Results

Fifty-six patients underwent PVI, either by PFA (n=28, age 63 [54; 75] y, 64% males, 57% persistent AF) or CBA (n=28, age 71 [62; 78] y, 61% males, 54% persistent AF). All 112 blood samples were analyzable. Acute success of PVI was 100% in both groups without major complications, especially, no TIA and no stroke. After CBA, one patient suffered from phrenic palsy, which reversed after 3 months. HsTropI increased 3.3-fold more after PFA compared to CBA (625±138 vs. 185±42 pg/ml; p=0.004) suggesting more damage to cardiomyocytyes. S100b increased 2.9-fold less after PFA compared to CBA (21.1±3.7 vs. 61.2±8.1 pg/ml; p<0.001). The ratio of ∆S100b/∆hsTropI was five-fold smaller after PFA compared to CBA (0.19±0.1 vs. 0.98±0.3; p=0.007), suggesting a lower neurocardiac injury in comparison to lesion size. Concomitantly, increase in heart rate at the postinterventional day was smaller in PFA (-0.2±3.0 bpm; n=45) than in CBA (+6.1±2.7 bpm, n=15; p=0.024).

Conclusion

This study in patients validates the experimental concept that PFA-based AF ablation leads to more specific damage to cardiomyocytes than to cardiac nerves and ganglia, reflected by lower S100B concentrations and no post-interventional heart rate increase compared to CBA.

Selective intracardiac sympathetic denervation acutely modulates left ventricular control

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Centre for Cardiovascular Research (DZHK)

Background

The sympathetic nervous system plays an integral role in cardiac physiology. Neuromodulation is emerging as a treatment option for ventricular arrhythmias, but selective intracardiac approaches are rare. Sympathetic nerve fibers innervating the left ventricle have been demonstrated to be amenable to transvenous catheter stimulation along the coronary sinus (CS).

Purpose

The aim of the present study was to modulate left ventricular control by selective sympathetic denervation using epicardial or standard catheter ablation for intracardiac axotomy at the level of the CS.

Methods

First, the impact of epicardial CS ablation on cardiac electrophysiology was studied in a Langendorff model of murine hearts (n=10 each, ablation and control). Second, the impact of transvenous, anatomically-driven axotomy by catheter-based radiofrequency ablation along the CS was evaluated in a healthy ovine in vivo model (n=8) before and during left stellate ganglion stimulation (LSGS).

Results

CS ablation for intracardiac sympathetic axotomy prolonged epicardial ventricular refractory period (VRP) without (41.8±8.4 ms vs. 53.0±13.5 ms; P=0.0487) and with beta1-2-adrenergic receptor blockade (47.8±2.8 ms vs. 73.1±5.0 ms; P=0.0009) and enhanced the increasing effect of beta1-2-adrenergic receptor blockade on epicardial VRP (∆VRP 6.3±7.0 ms vs. 20.0±7.5 ms; P=0.0045) in mice (Figure, A). Mean epicardial wave propagation velocity in the left ventricle was faster in ablated hearts than in controls (1.13±0.05 m/s vs. 1.00±0.02 m/s; P=0.0463), but did not differ in the right ventricle (1.15±0.05 m/s vs. 1.20±0.08 m/s; P=0.7938). Transvenous catheter ablation of the CS reduced systolic (SBP, 57.7±5.0 mmHg vs. 46.9±3.6 mmHg; P=0.0428) and diastolic blood pressure (DBP, 35.5±3.0 mmHg vs. 26.7±1.8 mmHg; P=0.0106) and diminished the blood pressure increase during LSGS in sheep (∆SBP 21.9±3.8 mmHg vs. 10.5±4.2 mmHg; P=0.0234; ∆DBP 9.0±1.9 mmHg vs. 3.0±1.2 mmHg; P=0.0391) (Figure, B, C). Cycle length remained unchanged by LSGS, both before (baseline 653.2±20.6 ms vs. LSGS 627.8±27.5 ms; P=0.2309) and after CS ablation (baseline 734.8±24.2 ms vs. LSGS 746.2±37.3 ms; P=0.7145).

Conclusions

Anatomically-driven axotomy targeting nerve fibers along the CS enables selective intracardiac sympathetic denervation resulting in acute modulation of left ventricular control.

Automated 3D Fetal Brain Segmentation Using an Optimized Deep Learning Approach

BACKGROUND AND PURPOSE

MR imaging provides critical information about fetal brain growth and development. Currently, morphologic analysis primarily relies on manual segmentation, which is time-intensive and has limited repeatability. This work aimed to develop a deep learning-based automatic fetal brain segmentation method that provides improved accuracy and robustness compared with atlas-based methods.

MATERIALS AND METHODS

A total of 106 fetal MR imaging studies were acquired prospectively from fetuses between 23 and 39 weeks of gestation. We trained a deep learning model on the MR imaging scans of 65 healthy fetuses and compared its performance with a 4D atlas-based segmentation method using the Wilcoxon signed-rank test. The trained model was also evaluated on data from 41 fetuses diagnosed with congenital heart disease.

RESULTS

The proposed method showed high consistency with the manual segmentation, with an average Dice score of 0.897. It also demonstrated significantly improved performance (P < .001) based on the Dice score and 95% Hausdorff distance in all brain regions compared with the atlas-based method. The performance of the proposed method was consistent across gestational ages. The segmentations of the brains of fetuses with high-risk congenital heart disease were also highly consistent with the manual segmentation, though the Dice score was 7% lower than that of healthy fetuses.

CONCLUSIONS

The proposed deep learning method provides an efficient and reliable approach for fetal brain segmentation, which outperformed segmentation based on a 4D atlas and has been used in clinical and research settings.

Clinical outcome after lumbar spinal fusion surgery in degenerative spondylolisthesis: a 3-year follow-up

INTRODUCTION

Lumbar spinal fusion surgery is a widely accepted surgical treatment in degenerative causes of lumbar spondylolisthesis. The benefit of reduction of anterior displacement and restoration of sagittal parameters is still controversially debated. Purpose of the underlying publication was to analyze the influence of radiographic sagittal parameters of the spine in aspects of changes in postoperative clinical outcome.

MATERIALS AND METHODS

By prospective analysis, we included patients with low-grade degenerative lumbar spondylolisthesis (Meyerding grades I and II) with mono- or bisegmental fusion surgery with a minimum follow-up data of 3 years. For clinical outcome measures, COMI, ODI and EQ-5D were used. Spinopelvic parameters (sacral inclination, pelvic tilt, sacral slope and pelvic incidence, lumbar lordosis and lumbar index as well as anterior displacement and sagittal rotation) were measured on plain radiographs.

RESULTS

We could observe a significant benefit in clinical outcome after lumbar fusion surgery in low-grade spondylolisthesis in our mid-term follow-up data including 32 patients. By surgical reduction, we could see significant restoration of anterior displacement and sagittal rotation. Interestingly, a significant correlation between restoration of both sagittal rotation and sacral inclination and clinical outcome score was observed in the 3-year follow-up.

CONCLUSION

In low-grade spondylolisthesis, spinal fusion surgery is a well-established surgical procedure; however, the impact of sagittal parameters and reduction of anterior displacement remains controversial. Within our findings, restoration of sagittal parameters showed significant correlation to improvement in clinical outcome in our mid-term follow-up data.

Search for Lepton-Flavor Violation in Z-Boson Decays with τ Leptons with the ATLAS Detector

A search for lepton-flavor-violating Z→eτ and Z→μτ decays with pp collision data recorded by the ATLAS detector at the LHC is presented. This analysis uses 139  fb^{-1} of Run 2 pp collisions at sqrt[s]=13  TeV and is combined with the results of a similar ATLAS search in the final state in which the τ lepton decays hadronically, using the same data set as well as Run 1 data. The addition of leptonically decaying τ leptons significantly improves the sensitivity reach for Z→ℓτ decays. The Z→ℓτ branching fractions are constrained in this analysis to B(Z→eτ)<7.0×10^{-6} and B(Z→μτ)<7.2×10^{-6} at 95% confidence level. The combination with the previously published analyses sets the strongest constraints to date: B(Z→eτ)<5.0×10^{-6} and B(Z→μτ)<6.5×10^{-6} at 95% confidence level.

Outcomes of novel pacing technologies with right ventricular pacing as a primary strategy for patient undergoing transvenous permanent pacing regardless of pacing indication

Background

Right ventricular pacing (RVP) may cause electrical and mechanical desynchrony leading to impaired left ventricular ejection fraction (LVEF). We investigated the outcomes of RVP with His bundle pacing (HBP) and left bundle branch pacing (LBBP) for patients requiring a de novo permeant pacemaker (PPM) irrespective of baseline pacing indication.

Methods and results

Systematic review of randomized clinical trials and observational studies comparing HBP or LBP with RVP for de novo PPM implantation between 01 January 2013 and 17 November 2020 using MEDLINE and Embase. Two independent reviewers extracted the data and assessed the risk of bias of included studies. Random and fixed effects meta-analyses of the effect of pacing technology on study outcomes (all-cause mortality, heart failure hospitalization (HFH), left ventricular ejection fraction, QRS duration, lead revision, atrial fibrillation and procedure and pacing metrics) were performed. Overall, 7 studies were included. HBP compared with RVP was associated with decreased mortality (risk ratio [RR] 0.76, 95% CI 0.59 to 0.98), preservation of LVEF (mean difference [MD] 1.2, 95% CI −1.37 to 3.8 vs. −5.22, 95% CI: −6.94 to −3.51), increased procedure duration (MD 15.17 min, 95% CI: 11.27 to 19.07) and more lead revisions (RR 6.30, 95% CI: 2.31 to 17.19). LBBP compared with RVP was associated with shorter paced QRS durations (MD 5.6 ms, 95% CI −6.4 to 17.6) vs. (51.0 ms, 95% CI 39.2 to 62.9) and increased procedure durations (MD 37.78 min, 95% CI: 20.04 to 55.51).

Conclusion

Of the limited studies published, this meta-analysis found that HBP and LBBP were superior to RVP in maintaining physiological ventricular activation as an initial pacing strategy. Well conducted comparative studies are required to understand the impact of such novel pacing strategies on clinical outcomes.

Funding Acknowledgement

Type of funding sources: None.

Search for New Phenomena in Final States with Two Leptons and One or No b-Tagged Jets at sqrt[s]=13 TeV Using the ATLAS Detector

A search for new phenomena is presented in final states with two leptons and one or no b-tagged jets. The event selection requires the two leptons to have opposite charge, the same flavor (electrons or muons), and a large invariant mass. The analysis is based on the full run-2 proton-proton collision dataset recorded at a center-of-mass energy of sqrt[s]=13  TeV by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 139  fb^{-1}. No significant deviation from the expected background is observed in the data. Inspired by the B-meson decay anomalies, a four-fermion contact interaction between two quarks (b, s) and two leptons (ee or μμ) is used as a benchmark signal model, which is characterized by the energy scale and coupling, Λ and g_{*}, respectively. Contact interactions with Λ/g_{*} lower than 2.0 (2.4) TeV are excluded for electrons (muons) at the 95% confidence level, still far below the value that is favored by the B-meson decay anomalies. Model-independent limits are set as a function of the minimum dilepton invariant mass, which allow the results to be reinterpreted in various signal scenarios.