1,411 research outputs found
Aortic valve replacement in octogenarians
<p>Abstract</p> <p>Background and Aims</p> <p>As our population ages and life expectancy increases the number of people aged over 80 and more referred for cardiac surgery is growing. This study sought to identify the outcome of aortic valve replacement (AVR) in octogenarians.</p> <p>Methods</p> <p>68 patients aged 80 years or more underwent AVR at the Freeman Hospital, between April 2001 and April 2004. A retrospective review of the notes and outcomes from the patients' GP and the NHS strategic tracking service was performed. 54% (37) underwent isolated AVR whilst 46% (31) underwent combined AVR and CABG.</p> <p>Results</p> <p>Follow up was 100% complete. The mean age was 83.1 ± s.d. 2.9 years, a mean gradient of 83 ± s.d. 31 mmHg and mean AVA of 0.56 cm<sup>2</sup>. The mean additive EuroSCORE was 8.6 ± s.d. 1.2, the logistic EuroSCORE mean 12.0 ± s.d. 5.9. In hospital 30 day mortality was 13 %. Survival was 80% at 1 year and 78% at 2 years. Median follow up was for 712 days. Stepwise logistic regression identified chronic obstructive airways disease as an independent predictor of mortality (p < 0.05). Survival was not adversely affected by the addition of coronary artery bypass grafts to aortic valve replacement, the presence of peripheral vascular disease, hypertension or diabetes. In this study duration of cross clamp or bypass time were not found to reach significance as independent predictors of mortality.</p> <p>Conclusion</p> <p>Our study demonstrates that the operative mortality for AVR in the over eighties is good, whilst the mid to long term outcome is excellent There is a very low attrition rate with those undergoing the procedure living as long than their age matched population. This study confirms AVR is a safe, acceptable treatment for octogenarians with excellent mid term outcomes.</p
A Low-Mass Pre-Main-Sequence Eclipsing Binary in Lower Centaurus Crux Discovered with TESS
We report the discovery of 2M1222-57 as a low-mass, pre-main-sequence (PMS)
eclipsing binary (EB) in the Lower Centaurus Crux (LCC) association for which,
using Gaia parallaxes and proper motions with a neural-net age estimator, we
determine an age of 16.22.2 Myr. The broadband spectral energy
distribution (SED) shows clear excess at ~10 um indicative of a circumbinary
disk, and new speckle-imaging observations reveal a faint, tertiary companion
separated by ~100 AU. H-alpha emission is modulated on the orbital period,
consistent with theoretical models of orbitally pulsed accretion streams
reaching from the inner disk edge to the central stars. From a joint analysis
of spectroscopically determined radial velocities and TESS light curves,
together with additional tight constraints provided by the SED and the Gaia
parallax, we measure masses for the eclipsing stars of 0.74 Msun and 0.67 Msun;
radii of 0.98 Rsun and 0.94 Rsun; and effective temperatures of 3750 K and 3645
K. The masses and radii of both stars are measured to an accuracy of ~1%. The
measured radii are inflated, and the temperatures suppressed, relative to
predictions of standard PMS evolutionary models at the age of LCC; also, the Li
abundances are ~2 dex less depleted than predicted by those models. However,
models that account for the global and internal effects of surface magnetic
fields are able to simultaneously reproduce the measured radii, temperatures,
and Li abundances at an age of 17.00.5 Myr. Altogether, the 2M1222-57
system presents very strong evidence that magnetic activity in young stars
alters both their global properties and the physics of their interiors.Comment: 23 pages, 19 figures, accepted by Ap
WASP-4b Arrived Early for the TESS Mission
The Transiting Exoplanet Survey Satellite (TESS) recently observed 18
transits of the hot Jupiter WASP-4b. The sequence of transits occurred 81.6
11.7 seconds earlier than had been predicted, based on data stretching
back to 2007. This is unlikely to be the result of a clock error, because TESS
observations of other hot Jupiters (WASP-6b, 18b, and 46b) are compatible with
a constant period, ruling out an 81.6-second offset at the 6.4 level.
The 1.3-day orbital period of WASP-4b appears to be decreasing at a rate of
milliseconds per year. The apparent period change
might be caused by tidal orbital decay or apsidal precession, although both
interpretations have shortcomings. The gravitational influence of a third body
is another possibility, though at present there is minimal evidence for such a
body. Further observations are needed to confirm and understand the timing
variation.Comment: AJ accepte
- …