Mitral regurgitation in patients with severe aortic stenosis: Diagnosis and management

Severe aortic stenosis (AS) and mitral regurgitation (MR) frequently coexist. Although some observational studies have reported that moderate or severe MR is associated with higher mortality, the optimal management of such patients is still unclear. Simultaneous replacement of both aortic and mitral valves is linked to significantly higher morbidity and mortality. Recent advances in minimally invasive surgical or transcatheter therapies for MR allow for staged procedures in which surgical or transcatheter aortic valve replacement (SAVR/TAVR) is done first and MR severity re-evaluated afterwards. Current evidence suggests MR severity improves in some patients after SAVR or TAVR, depending on several factors (MR aetiology, type of valve used for TAVR, presence/absence of atrial fibrillation, residual aortic regurgitation, etc). However, as of today, the absence of randomised clinical trials does not allow for evidence-based recommendations about whether or not MR should be addressed at the time of SAVR or TAVR. A careful patient evaluation and clinical judgement are recommended to distinguish patients who might benefit from a double valve intervention from those in which MR should be left alone. The aim of this review is to report and critique the available data on this subject in order to help guide the clinical decision making in this challenging subset of patients

Proportionate and Disproportionate Functional Mitral Regurgitation: A New Conceptual Framework That Reconciles the Results of the MITRA-FR and COAPT Trials

Traditional approaches to the characterization of secondary or functional mitral regurgitation (MR) have largely ignored the critical importance of the left ventricle (LV). We propose that patients with secondary MR represent a heterogenous group, which can be usefully subdivided based on understanding that the effective regurgitant orifice area (EROA) is dependent on left ventricular end-diastolic volume (LVEDV). According to the Gorlin hydraulic orifice equation, patients with heart failure, an LV ejection fraction of 30%, an LVEDV of 220 to 250 ml, and a regurgitant fraction of 50% would be expected to have an EROA of ≈0.3 cm2 independent of specific tethering abnormalities of the mitral valve leaflets. The MR in these patients is proportionate to the degree of LV dilatation and can respond to drugs and devices that reduce LVEDV. In contrast, patients with EROA of 0.3 to 0.4 cm2 but with LVEDV of only 160 to 200 ml exhibit degrees of MR that are disproportionately higher than predicted by LVEDV. These patients appear to preferentially benefit from interventions directed at the mitral valve. Our proposed conceptual framework explains the apparently discordant results from 2 recent randomized controlled trials of mitral valve repair. The MITRA-FR (Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation) trial enrolled patients who had MR that was proportionate to the degree of LV dilatation, and during long-term follow-up, the LVEDV and clinical outcomes of these patients did not differ from medically-treated control subjects. In comparison, the patients enrolled in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial had an EROA ≈30% higher but LV volumes that were ≈30% smaller, indicative of disproportionate MR. In these patients, transcatheter mitral valve repair reduced the risk of death and hospitalization for heart failure, and these benefits were paralleled by a meaningful decrease in LVEDV. Thus, characterization of MR as proportionate or disproportionate to LVEDV appears to be critical to the selection of an optimal treatment for patients with chronic heart failure and systolic dysfunction

Confinement and Chiral Symmetry

We illustrate why color deconfines when chiral symmetry is restored in gauge theories with quarks in the fundamental representation, and while these transitions do not need to coincide when quarks are in the adjoint representation, entanglement between them is still present.Comment: 4 pages, 1 figure, proceedings of Quark Matter 200

Extending the Veneziano-Yankielowicz Effective Theory

We extend the Veneziano Yankielowicz (VY) effective theory in order to account for ordinary glueball states. We propose a new form of the superpotential including a chiral superfield for the glueball degrees of freedom. When integrating it ``out'' we obtain the VY superpotential while the N vacua of the theory naturally emerge. This fact has a counterpart in the Dijkgraaf and Vafa geometric approach. We suggest a link of the new field with the underlying degrees of freedom which allows us to integrate it ``in'' the VY theory. We finally break supersymmetry by adding a gluino mass and show that the Kahler independent part of the ``potential'' has the same form of the ordinary Yang-Mills glueball effective potential.Comment: LaTeX, 20 page

A study of the influence of the gauge group on the Dyson-Schwinger equations for scalar-Yang-Mills systems

The particular choice of the gauge group for Yang-Mills theory plays an important role when it comes to the influence of matter fields. In particular, both the chosen gauge group and the representation of the matter fields yield structural differences in the quenched case. Especially, the qualitative behavior of the Wilson potential is strongly dependent on this selection. Though the algebraic reasons for this observation is clear, it is far from obvious how this behavior can be described besides using numerical simulations. Herein, it is investigated how the group structure appears in the Dyson-Schwinger equations, which as a hierarchy of equations for the correlation functions have to be satisfied. It is found that there are differences depending on both the gauge group and the representation of the matter fields. This provides insight into possible truncation schemes for practical calculations using these equations.Comment: 47 page

Technicolor and Beyond: Unification in Theory Space

The salient features of models of dynamical electroweak symmetry breaking are reviewed. The ideal walking idea is introduced according to which one should carefully take into account the effects of the extended technicolor dynamics on the technicolor dynamics itself. The effects amount at the enhancement of the anomalous dimension of the mass of the techniquarks allowing to decouple the Flavor Changing Neutral Currents problem from the one of the generation of the top mass. Precision data constraints are reviewed focussing on the latest crucial observation that the S-parameter can be computed exactly near the upper end of the conformal window (Conformal S-parameter) with relevant consequences on the selection of nature's next strong force. We will then introduce the Minimal Walking Technicolor (MWT) models. In the second part of this review we consider the interesting possibility to marry supersymmetry and technicolor. The reason is to provide a unification of different extensions of the standard model. For example, this means that one can recover, according to the parameters and spectrum of the theory distinct extensions of the standard model, from supersymmetry to technicolor and unparticle physiscs. A surprising result is that a minimal (in terms of the smallest number of fields) supersymmetrization of the MWT model leads to the maximal supersymmetry in four dimensions, i.e. N=4 SYM.Comment: Extended version of the PASCOS10 proceedings for the Plenary Tal

Effective Lagrangians for Orientifold Theories

We construct effective Lagrangians of the Veneziano-Yankielowicz (VY) type for two non-supersymmetric theories which are orientifold daughters of supersymmetric gluodynamics (containing one Dirac fermion in the two-index antisymmetric or symmetric representation of the gauge group). Since the parent and daughter theories are planar equivalent, at N\to\infty the effective Lagrangians in the orientifold theories basically coincide with the bosonic part of the VY Lagrangian. We depart from the supersymmetric limit in two ways. First, we consider finite (albeit large) values of N. Then 1/N effects break supersymmetry. We suggest seemingly the simplest modification of the VY Lagrangian which incorporates these 1/N effects, leading to a non-vanishing vacuum energy density. We analyze the spectrum of the finite-N non-supersymmetric daughters. For N=3 the two-index antisymmetric representation (one flavor) is equivalent to one-flavor QCD. We show that in this case the scalar quark-antiquark state is heavier than the corresponding pseudoscalar state, `` eta' ''. Second, we add a small fermion mass term. The fermion mass term breaks supersymmetry explicitly. The vacuum degeneracy is lifted. The parity doublets split. We evaluate the splitting. Finally, we include the theta-angle and study its implications.Comment: LaTeX, 21 page

Flow regimes study within the Strait of Gibraltar using a high-performance numerical model

A three-dimensional sigma coordinate free-surface high-performance model is used to investigate the flow regimes within the Strait of Gibraltar. High performances are achieved through a directive-based, MPI-like, parallelization of the code, obtained using SMS tool. The model makes use of a coastal-following, curvilinear orthogonal grid, that includes the Gulf of Cadiz and the Alboran Sea, reaching very high resolution in the Strait. Four experiments with different initial salinity conditions representing the present and possible future climate conditions over the Mediterranean basin have been performed. Model results, analysed by means of the three-layer composite Froude number theory, have shown two different possible regimes within the strait; for the present climate condition the strait is subjected to a sub-maximal regimewhilefor possible future climate conditions a maximal regime can be reached

Comparison of Baseline Characteristics and Outcomes in Men Versus Women With Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation

Female gender has been linked to increased risk of adverse events after surgical aortic valve replacement; however, the evidence regarding the role of gender differences on clinical outcomes in patients who underwent transcatheter aortic valve implantation (TAVI) is still debated. This retrospective study included 910 consecutive patients with severe, symptomatic aortic stenosis who underwent TAVI in 2 institutions from January 2012 to July 2016. The primary end point was all-cause mortality at 1 year after TAVI in women versus men. Women had a higher incidence of in-hospital vascular complications (7.8% vs 4.1%) and major or life-threatening bleeding (4.0% vs 1.6%) than men. At 1 year, women showed a lower mortality rate than men (7.0% vs 12.7%, adjusted hazard ratio [HR] 0.42, 95% confidence interval [CI] [0.23 to 0.76], p = 0.004). When stratifying by specific subgroups of interest, the survival benefit in women persisted in (1) patients with a Society of Thoracic Surgery risk score ≤ 8 (adjusted HR 0.35, 95% CI [0.14 to 0.88], p = 0.026); (2) patients treated with first-generation devices (adjusted HR 0.46, 95% CI [0.24 to 0.86], p = 0.016); and (3) patients treated with balloon-expandable valves (adjusted HR 0.40, 95% CI [0.19 to 0.86], p = 0.019). In conclusion, in this large patient cohort, women had lower 1-year mortality after TAVI than men, particularly with an STS score ≤ 8, or treated with first-generation and balloon-expandable devices

Polyakov Loops versus Hadronic States

The order parameter for the pure Yang-Mills phase transition is the Polyakov loop which encodes the symmetries of the Z_N center of the SU(N) gauge group. On the other side the physical degrees of freedom of any asymptotically free gauge theory are hadronic states. Using the Yang-Mills trace anomaly and the exact Z_N symmetry we construct a model able to communicate to the hadrons the information carried by the order parameter.Comment: RevTex4 2-col., 6 pages, 2 figures. Typos fixed and added a paragraph in the conclusion