834 research outputs found
β blockers and mortality after myocardial infarction in patients without heart failure: multicentre prospective cohort study
Objective: To assess the association between early and prolonged β blocker treatment and mortality after acute myocardial infarction. Design: Multicentre prospective cohort study. Setting: Nationwide French registry of Acute ST- and non-ST-elevation Myocardial Infarction (FAST-MI) (at 223 centres) at the end of 2005. Participants: 2679 consecutive patients with acute myocardial infarction and without heart failure or left ventricular dysfunction. Main outcome measures: Mortality was assessed at 30 days in relation to early use of β blockers (≤48 hours of admission), at one year in relation to discharge prescription, and at five years in relation to one year use. Results: β blockers were used early in 77% (2050/2679) of patients, were prescribed at discharge in 80% (1783/2217), and were still being used in 89% (1230/1383) of those alive at one year. Thirty day mortality was lower in patients taking early β blockers (adjusted hazard ratio 0.46, 95% confidence interval 0.26 to 0.82), whereas the hazard ratio for one year mortality associated with β blockers at discharge was 0.77 (0.46 to 1.30). Persistence of β blockers at one year was not associated with lower five year mortality (hazard ratio 1.19, 0.65 to 2.18). In contrast, five year mortality was lower in patients continuing statins at one year (hazard ratio 0.42, 0.25 to 0.72) compared with those discontinuing statins. Propensity score and sensitivity analyses showed consistent results. Conclusions: Early β blocker use was associated with reduced 30 day mortality in patients with acute myocardial infarction, and discontinuation of β blockers at one year was not associated with higher five year mortality. These findings question the utility of prolonged β blocker treatment after acute myocardial infarction in patients without heart failure or left ventricular dysfunction. Trial registration: Clinical trials NCT00673036
Orbital characterization of GJ1108A system, and comparison of dynamical mass with model-derived mass for resolved binaries
We report an orbital characterization of GJ1108Aab that is a low-mass binary
system in pre-main-sequence phase. Via the combination of astrometry using
adaptive optics and radial velocity measurements, an eccentric orbital solution
of =0.63 is obtained, which might be induced by the Kozai-Lidov mechanism
with a widely separated GJ1108B system. Combined with several observed
properties, we confirm the system is indeed young. Columba is the most probable
moving group, to which the GJ1108A system belongs, although its membership to
the group has not been established. If the age of Columba is assumed for
GJ1108A, the dynamical masses of both GJ1108Aa and GJ1108Ab ( and ) are more massive than what an
evolutionary model predicts based on the age and luminosities. We consider the
discrepancy in mass comparison can attribute to an age uncertainty; the system
is likely older than stars in Columba, and effects that are not implemented in
classical models such as accretion history and magnetic activity are not
preferred to explain the mass discrepancy. We also discuss the performance of
the evolutionary model by compiling similar low-mass objects in evolutionary
state based on the literature. Consequently, it is suggested that the current
model on average reproduces the mass of resolved low-mass binaries without any
significant offsets.Comment: Accepted in Ap
Shadows and spirals in the protoplanetary disk HD 100453
Understanding the diversity of planets requires to study the morphology and
the physical conditions in the protoplanetary disks in which they form. We
observed and spatially resolved the disk around the ~10 Myr old protoplanetary
disk HD 100453 in polarized scattered light with SPHERE/VLT at optical and
near-infrared wavelengths, reaching an angular resolution of ~0.02", and an
inner working angle of ~0.09". We detect polarized scattered light up to ~0.42"
(~48 au) and detect a cavity, a rim with azimuthal brightness variations at an
inclination of 38 degrees, two shadows and two symmetric spiral arms. The
spiral arms originate near the location of the shadows, close to the semi major
axis. We detect a faint spiral-like feature in the SW that can be interpreted
as the scattering surface of the bottom side of the disk, if the disk is
tidally truncated by the M-dwarf companion currently seen at a projected
distance of ~119 au. We construct a radiative transfer model that accounts for
the main characteristics of the features with an inner and outer disk
misaligned by ~72 degrees. The azimuthal brightness variations along the rim
are well reproduced with the scattering phase function of the model. While
spirals can be triggered by the tidal interaction with the companion, the close
proximity of the spirals to the shadows suggests that the shadows could also
play a role. The change in stellar illumination along the rim, induces an
azimuthal variation of the scale height that can contribute to the brightness
variations. Dark regions in polarized images of transition disks are now
detected in a handful of disks and often interpreted as shadows due to a
misaligned inner disk. The origin of such a misalignment in HD 100453, and of
the spirals, is unclear, and might be due to a yet-undetected massive companion
inside the cavity, and on an inclined orbit.Comment: A&A, accepte
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