Survival after bidirectional cavopulmonary anastomosis: Analysis of preoperative risk factors

ObjectivePrognostic factors for survival after bidirectional cavopulmonary anastomosis for functionally single ventricle are not well defined. We analyzed preoperative hemodynamic and echocardiographic data to determine risk factors for death or transplantation at least 1 year after bidirectional cavopulmonary anastomosis.MethodsData for all patients who underwent bidirectional cavopulmonary anastomosis before 5 years of age at our institution from September 1995 through June 2005 were analyzed. Available preoperative echocardiograms and catheterizations were reviewed. Survivors were compared with those who died or underwent transplantation. Bivariable associations between demographic and clinical risk factors and survival status (alive without transplantation vs dead or transplanted) were assessed with Wilcoxon rank sum test and χ2 or Fisher exact tests. Survival functions were constructed with Kaplan–Meier estimates, and event times compared between subgroups with log–rank tests. Cox proportional hazard modeling was used for multivariable modeling of risk of death or transplantation.ResultsOne hundred sixty-seven patients underwent bidirectional cavopulmonary anastomosis with hemi-Fontan (n = 62) or bidirectional Glenn (n = 105) operations. Three patients died before discharge, 11 died later, and 1 has undergone transplantation. Freedom from death or transplantation after bidirectional cavopulmonary anastomosis was 96% at 1 year and 89% at 5 years. Multivariable analysis of preoperative variables showed atrioventricular valve regurgitation to be an independent risk factor for death or transplantation (hazard ratio 2.8, 95% confidence interval 1.1–7.1, P = .02).ConclusionAlthough survival after bidirectional cavopulmonary anastomosis is high, preoperative atrioventricular valve regurgitation is an important risk factor for death or transplantation

Survival and Clinical Course at Fontan After Stage One Palliation With Either a Modified Blalock-Taussig Shunt or a Right Ventricle to Pulmonary Artery Conduit

ObjectivesWe sought to determine whether the type of shunt used at stage one palliation (S1P) affected the survival and the perioperative course through Fontan completion.BackgroundAlthough improved surgical and interstage survival have been demonstrated with the use of the right ventricle to pulmonary artery (RV-PA) conduit compared with a modified Blalock-Taussig shunt (BTS) at S1P, it is unknown whether this effect will be observed in long-term follow-up.MethodsAll patients who underwent a S1P during 2002 and 2003 (n = 80) at our institution were included for analysis. Patients were followed until death or June 1, 2007. Perioperative variables at Fontan completion were recorded.ResultsFor the entire cohort, cumulative survival for those who underwent a RV-PA conduit (n = 34) was 79.4% at 3 years compared with 65.8% in the modified BTS group (n = 46) (log-rank = 0.31). At Fontan (n = 44), when compared with those who had received a modified BTS, those who had a RV-PA conduit placed at S1P had no difference in the median duration of ventilation (21 h [range 10 to 96 h] vs. 26.5 h [range 7 to 204 h], p = 0.09) or hospital stay (9 days [range 5 to 29 days] vs. 10 days [range 6 to 48 days], p = 0.89), although length of stay in the intensive care unit was shorter (2 days [range 0 to 6 days] vs. 4 days [range 1 to 25 days], p = 0.01). Sixty-seven percent of the RV-PA conduit group had at least one PA intervention 3 years after S1P compared with 42.8% in the modified BTS group (log-rank = 0.11).ConclusionsNonstatistically significant trends toward improved cumulative survival and increased PA interventions were demonstrated in patients who had a RV-PA conduit placed at S1P. Longitudinal follow-up of larger groups of randomized patients is required to determine the influence of the RV-PA conduit on long-term outcomes

Hospital Costs Related to Early Extubation after Infant Cardiac Surgery

Background The Pediatric Heart Network Collaborative Learning Study (PHN CLS) increased early extubation rates after infant Tetralogy of Fallot (TOF) and coarctation (CoA) repair across participating sites by implementing a clinical practice guideline (CPG). The impact of the CPG on hospital costs has not been studied. Methods PHN CLS clinical data were linked to cost data from Children’s Hospital Association by matching on indirect identifiers. Hospital costs were evaluated across active and control sites in the pre- and post-CPG periods using generalized linear mixed effects models. A difference-in-difference approach was used to assess whether changes in cost observed in active sites were beyond secular trends in control sites. Results Data were successfully linked on 410/428 (96%) of eligible patients from 4 active and 4 control sites. Mean adjusted cost/case for TOF repair was significantly reduced in the post-CPG period at active sites ($42,833 vs.$56,304, p<0.01) and unchanged at control sites ($47,007 vs.$46,476, p=0.91), with an overall cost reduction of 27% in active vs. control sites (p=0.03). Specific categories of cost reduced in the TOF cohort included clinical (-66%, p<0.01), pharmacy (-46%, p=0.04), lab (-44%, p<0.01), and imaging (-32%, p<0.01). There was no change in costs for CoA repair at active or control sites. Conclusions The early extubation CPG was associated with a reduction in hospital costs for infants undergoing repair of TOF, but not CoA repair. This CPG represents an opportunity to both optimize clinical outcome and reduce costs for certain infant cardiac surgeries

Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

This paper presents new sets of parameters (“tunes”) for the underlying-event model of the HERWIG7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in HERWIG7, and are obtained from a fit to minimum-bias data collected by the CMS experiment at s=0.9, 7, and 13Te. The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the dat

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| &lt; 0.03 at 95% confidence level. [Figure not available: see fulltext.

Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.Peer reviewe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Measurement of b jet shapes in proton-proton collisions at root s=5.02 TeV

We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb(-1). To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.Peer reviewe

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe