35 research outputs found
Cardiovascular drug utilization post-implant is related to clinical outcome in heart failure patients receiving cardiac resynchronization therapy
Background: In select patients with heart failure, cardiac resynchronization therapy (CRT) is the most common complementary treatment besides medical treatment. We aimed to assess the association between post CRT-implant changes in cardiovascular medication and cardiovascular mortality and heart failure hospitalization.
Methods: 211 patients on optimal medical therapy eligible for CRT were retrospectively included in this study (72 ± 7 years, 80% male, 66% left bundle branch block, 48% dilated cardiomyopathy and investigated at baseline and after 6 months. Follow-up with medication, biochemical markers and echocardiography was performed and 3-year mortality data was collected.
Results: At 6 months post-implant the cohort was divided into two groups; 157 patients had low dosage furosemide treatment (up to 40 mg) and 54 patients were treated with high dosage (> 40 mg). A composite endpoint of heart failure hospitalization and all-cause mortality was evaluated at 30 months (881 ± 267 days) after the 6-month visit. In multivariate Cox regression analysis, patients in the high dose diuretics group had a higher risk of the primary endpoint (HR 1.9 [1.1–3.4], p = 0.033), but treatment with high dose diuretics was not associated with improved clinical symptoms (r = 0.031, p = 0.64).
Conclusions: High dosage of loop-diuretics was associated with worse medium-term clinical outcome in CRT treated patients. It is unclear whether there is a direct causality between these associations, or if higher prescribed dosage of loop-diuretics is just a marker of more severe disease. Higher dose loop diuretics do not necessarily improve the symptoms and may be harmful to the patient. Prospective trials are warranted to further elucidate these findings. (Cardiol J 2017; 24, 4: 374–384
Stellar rotational periods in the planet hosting open cluster Praesepe
By using the dense coverage of the extrasolar planet survey project HATNet,
we Fourier analyze 381 high-probability members of the nearby open cluster
Praesepe (Beehive/M44/NGC 2632). In addition to the detection of 10 variables
(of \delta Scuti and other types), we identify 180 rotational variables
(including the two known planet hosts). This sample increases the number of
known rotational variables in this cluster for spectral classes earlier than M
by more than a factor of three. These stars closely follow a color/magnitude --
period relation from early F to late K stars. We approximate this relation by
polynomials for an easier reference to the rotational characteristics in
different colors. The total (peak-to-peak) amplitudes of the large majority
(94%) of these variables span the range of 0.005 to 0.04 mag. The periods cover
a range from 2.5 to 15 days. These data strongly confirm that Praesepe and the
Hyades have the same gyrochronological ages. Regarding the two planet hosts,
Pr0211 (the one with the shorter orbital period) has a rotational period that
is ~2 days shorter than the one expected from the main rotational pattern in
this cluster. This, together with other examples discussed in the paper, may
hint that star-planet interaction via tidal dissipation can be significant in
some cases in the rotational evolution of stars hosting Hot Jupiters.Comment: 17 pages, 13 figures, 5 tables; accepted for publication in MNRA
Patient-assessed short-term positive response to cardiac resynchronization therapy is an independent predictor of long-term mortality.
Cardiac resynchronization therapy (CRT) has a well-documented positive effect on mortality and heart failure morbidity. The aim of this study was to assess the long-term survival and the predictive value of self-assessed functional status on the long-term prognosis of patients treated with CRT-pacemaker (CRT-P).METHODS AND RESULTS: Data were retrospectively collected from medical records of 446 consecutive patients implanted with CRT-P at a large-volume Swedish tertiary care centre. Primary outcome was all-cause mortality, predictive variables were assessed by log-rank test and univariate cox regression. Three hundred and nine patients had reliable information available on early improvement after implantation and were included in the multivariate analyses. The cohort was followed for a median of 79 months and was similar in baseline characteristics compared with major controlled trials. During follow-up 204 patients died, yearly mortality was 11.7%. Early improvement of self-assessed functional status was a strong independent predictor of survival [hazard ratio, HR 0.59, confidence interval (CI) 0.40-0.87, P = 0.007], together with well-known predictors; NYHA III-IV vs I-II (HR 1.66, CI 1.09-2.536, P = 0.018), age (HR 1.05, CI 1.03-1.08, P < 0.001), male gender (HR 2.0, CI 1.11-3.45, P = 0.021), and loop diuretic use (HR 4.41, CI 1.08-18.02). Patients with early improvement of self-assessed functional status had better 2-year and 5-year survival (P < 0.001).CONCLUSIONS: Real-life patient characteristics and predictors of outcome compare well with those in published prospective trials. Self-assessed functional status is a strong predictor of long-term survival, which may have implications for a more active follow-up of patients without spontaneous improvement
HATS-18 b: An Extreme Short--Period Massive Transiting Planet Spinning Up Its Star
We report the discovery by the HATSouth network of HATS-18 b: a 1.980 +/-
0.077 Mj, 1.337 +0.102 -0.049 Rj planet in a 0.8378 day orbit, around a solar
analog star (mass 1.037 +/- 0.047 Msun, and radius 1.020 +0.057 -0.031 Rsun)
with V=14.067 +/- 0.040 mag. The high planet mass, combined with its short
orbital period, implies strong tidal coupling between the planetary orbit and
the star. In fact, given its inferred age, HATS-18 shows evidence of
significant tidal spin up, which together with WASP-19 (a very similar system)
allows us to constrain the tidal quality factor for Sun-like stars to be in the
range 6.5 <= lg(Q*/k_2) <= 7 even after allowing for extremely pessimistic
model uncertainties. In addition, the HATS-18 system is among the best systems
(and often the best system) for testing a multitude of star--planet
interactions, be they gravitational, magnetic or radiative, as well as planet
formation and migration theories.Comment: Submitted. 12 pages, 9 figures, 5 table
No Conclusive Evidence for Transits of Proxima b in MOST photometry
The analysis of Proxima Centauri's radial velocities recently led
Anglada-Escud\'e et al. (2016) to claim the presence of a low mass planet
orbiting the Sun's nearest star once every 11.2 days. Although the a-priori
probability that Proxima b transits its parent star is just 1.5%, the potential
impact of such a discovery would be considerable. Independent of recent radial
velocity efforts, we observed Proxima Centauri for 12.5 days in 2014 and 31
days in 2015 with the MOST space telescope. We report here that we cannot make
a compelling case that Proxima b transits in our precise photometric time
series. Imposing an informative prior on the period and phase, we do detect a
candidate signal with the expected depth. However, perturbing the phase prior
across 100 evenly spaced intervals reveals one strong false-positive and one
weaker instance. We estimate a false-positive rate of at least a few percent
and a much higher false-negative rate of 20-40%, likely caused by the very high
flare rate of Proxima Centauri. Comparing our candidate signal to HATSouth
ground-based photometry reveals that the signal is somewhat, but not
conclusively, disfavored (1-2 sigmas) leading us to argue that the signal is
most likely spurious. We expect that infrared photometric follow-up could more
conclusively test the existence of this candidate signal, owing to the
suppression of flare activity and the impressive infrared brightness of the
parent star.Comment: Accepted to ApJ. Posterior samples, MOST photometry and HATSouth
photometry are all available at https://github.com/CoolWorlds/Proxim
HAT-P-50b, HAT-P-51b, HAT-P-52b, and HAT-P-53b: Three Transiting Hot Jupiters and a Transiting Hot Saturn From the HATNet Survey
We report the discovery and characterization of four transiting exoplanets by
the HATNet survey. The planet HAT-P-50b has a mass of 1.35 M_J and a radius of
1.29 R_J, and orbits a bright (V = 11.8 mag) M = 1.27 M_sun, R = 1.70 R_sun
star every P = 3.1220 days. The planet HAT-P-51b has a mass of 0.31 M_J and a
radius of 1.29 R_J, and orbits a V = 13.4 mag, M = 0.98 M_sun, R = 1.04 R_sun
star with a period of P = 4.2180 days. The planet HAT-P-52b has a mass of 0.82
M_J and a radius of 1.01 R_J, and orbits a V = 14.1 mag, M = 0.89 M_sun, R =
0.89 R_sun star with a period of P = 2.7536 days. The planet HAT-P-53b has a
mass of 1.48 M_J and a radius of 1.32 R_J, and orbits a V = 13.7 mag, M = 1.09
M_sun, R = 1.21 R_sun star with a period of P = 1.9616 days. All four planets
are consistent with having circular orbits and have masses and radii measured
to better than 10% precision. The low stellar jitter and favorable R_P/R_star
ratio for HAT-P-51 make it a promising target for measuring the
Rossiter-McLaughlin effect for a Saturn-mass planet.Comment: Submitted to AJ. 20 pages, 9 figures, 5 tables. Data available at
http://hatnet.org