37 research outputs found

    Accounting for the foreground contribution to the dust emission towards Kepler's supernova remnant

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    ‘The definitive version is available at www3.interscience.wiley.com '. Copyright Royal Astronomical Society. DOI: 10.1111/j.1365-2966.2009.15061.xWhether or not supernovae contribute significantly to the overall dust budget is a controversial subject. Submillimetre (sub-mm) observations, sensitive to cold dust, have shown an excess at 450 and 850 μm in young remnants Cassiopeia A (Cas A) and Kepler. Some of the sub-mm emission from Cas A has been shown to be contaminated by unrelated material along the line of sight. In this paper, we explore the emission from material towards Kepler using sub-mm continuum imaging and spectroscopic observations of atomic and molecular gas, via H i, 12CO(J= 2–1) and 13CO(J= 2–1). We detect weak CO emission (peak T*A = 0.2–1 K, 1–2 km s−1 full width at half-maximum) from diffuse, optically thin gas at the locations of some of the sub-mm clumps. The contribution to the sub-mm emission from foreground molecular and atomic clouds is negligible. The revised dust mass for Kepler's remnant is 0.1–1.2 M⊙ , about half of the quoted values in the original study by Morgan et al., but still sufficient to explain the origin of dust at high redshifts.Peer reviewe

    Change in angina symptom status after acute myocardial infarction and its association with readmission risk: An analysis of the translational research investigating underlying disparities in acute myocardial infarction patients' health status (TRIUMPH) registry

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    Angina is common both before and after myocardial infarction (MI). Whether the change in angina status within the first 30 days after MI is associated with subsequent readmission and angina persistence is unknown.We studied 2915 MI patients enrolled at 24 hospitals in the Translational Research Investigating Underlying Disparities in Acute Myocardial Infarction Patients' Health Status (TRIUMPH) registry. Angina before and 30 days after MI was assessed with the Seattle Angina Questionnaire. Patients were divided into angina-free pre- and post-MI (-/-), resolved angina (+/-), new angina (-/+), and persistent angina (+/+) groups. Multivariable proportional hazards and hierarchical modified Poisson models were performed to assess the association of each group with all-cause readmission, readmission for MI or unplanned revascularization, and angina persistence at 1 year. Overall, 1293 patients (44%) had angina before their MI and 849 (29%) reported angina within 30 days of discharge. Patients with post-MI angina were more likely to be younger, nonwhite, and uninsured. Compared with patients who were angina-free pre- and post-MI, 1-year all-cause readmission risks were significantly higher for patients with persistent angina (hazard ratio [HR], 1.35; 95% CI 1.06-1.71) or new angina (HR, 1.40; 95% CI, 1.08-1.82). At 1 year, angina was present in 22% of patients and was more likely if angina was persistent (HR, 3.55; 95% CI, 3.05-4.13) or new (HR, 3.38; 95% CI, 2.59-4.42) at 30 days compared with patients who were angina-free pre- and post-MI.Post-MI angina, whether new or persistent, is associated with higher likelihood of readmission. Prioritizing post-MI angina management is a potential means of improving 1-year outcomes.Jacob A. Doll, Fengming Tang, Sharon Cresci, P. Michael Ho, Thomas M. Maddox, John A. Spertus and Tracy Y. Wan

    H-ATLAS/GAMA and HeViCS - dusty early-type galaxies in different environments

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    NKA acknowledges the support of the Science and Technology Facilities Council. LD, RJI and SJM acknowledge support from the European Research Council Advanced Grant COSMICISM. IDL gratefully acknowledges the support of the Flemish Fund for Scientific Research (FWO-Vlaanderen). KR acknowledges support from the European Research Council Starting Grant SEDmorph (P.I. V. Wild). Date of acceptance: 22/05/2015The Herschel Space Observatory has had a tremendous impact on the study of extragalactic dust. Specifically, early-type galaxies (ETG) have been the focus of several studies. In this paper, we combine results from two Herschel studies -a Virgo cluster study Herschel Virgo Cluster Survey (HeViCS) and a broader, low-redshift Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS)/Galaxy and Mass Assembly (GAMA) study -and contrast the dust and associated properties for similar mass galaxies. This comparison is motivated by differences in results exhibited between multiple Herschel studies of ETG. A comparison between consistent modified blackbody derived dust mass is carried out, revealing strong differences between the two samples in both dust mass and dust-to-stellar mass ratio. In particular, the HeViCS sample lacks massive ETG with as high a specific dust content as found in H-ATLAS. This is most likely connected with the difference in environment for the two samples. We calculate nearest neighbour environment densities in a consistent way, showing that H-ATLAS ETG occupy sparser regions of the local Universe, whereas HeViCS ETG occupy dense regions. This is also true for ETG that are not Herschel-detected but are in the Virgo and GAMA parent samples. Spectral energy distributions are fit to the panchromatic data. From these, we find that in H-ATLAS the specific star formation rate anticorrelates with stellar mass and reaches values as high as in our Galaxy. On the other hand HeViCS ETG appear to have little star formation. Based on the trends found here, H-ATLAS ETG are thought to have more extended star formation histories and a younger stellar population than HeViCS ETG.Publisher PDFPeer reviewe

    Association of Glycemic Control Trajectory with Short-Term Mortality in Diabetes Patients with High Cardiovascular Risk: a Joint Latent Class Modeling Study

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    Background: The relationship between risk factor or biomarker trajectories and contemporaneous short-term clinical outcomes is poorly understood. In diabetes patients, it is unknown whether hemoglobin A1c (HbA1c) trajectories are associated with clinical outcomes and can inform care in scenarios in which a single HbA1c is uninformative, for example, after a diagnosis of coronary artery disease (CAD). Objective: To compare associations of HbA1c trajectories and single HbA1c values with short-term mortality in diabetes patients evaluated for CAD Design: Retrospective observational cohort study Participants: Diabetes patients (n = 7780) with and without angiographically defined CAD Main Measures: We used joint latent class mixed models to simultaneously fit HbA1c trajectories and estimate association with 2-year mortality after cardiac catheterization, adjusting for clinical and demographic covariates. Key Results: Three HBA1c trajectory classes were identified: individuals with stable glycemia (class A; n = 6934 [89%]; mean baseline HbA1c 6.9%), with declining HbA1c (class B; n = 364 [4.7%]; mean baseline HbA1c 11.6%), and with increasing HbA1c (class C; n = 482 [6.2%]; mean baseline HbA1c 8.5%). HbA1c trajectory class was associated with adjusted 2-year mortality (3.0% [95% CI 2.8, 3.2] for class A, 3.1% [2.1, 4.2] for class B, and 4.2% [3.4, 4.9] for class C; global P = 0.047, P = 0.03 comparing classes A and C, P > 0.05 for other pairwise comparisons). Baseline HbA1c was not associated with 2-year mortality (P = 0.85; hazard ratios 1.01 [0.96, 1.06] and 1.02 [0.95, 1.10] for HbA1c 7–9% and ≥ 9%, respectively, relative to HbA1c < 7%). The association between HbA1c trajectories and mortality did not differ between those with and without CAD (interaction P = 0.1). Conclusions: In clinical settings where single HbA1c measurements provide limited information, HbA1c trajectories may help stratify risk of complications in diabetes patients. Joint latent class modeling provides a generalizable approach to examining relationships between biomarker trajectories and clinical outcomes in the era of near-universal adoption of electronic health records

    Very High-Risk ASCVD and Eligibility for Nonstatin Therapies Based on the 2018 AHA/ACC Cholesterol Guidelines

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    The 2018 American Heart Association/American College of Cardiology Multisociety Cholesterol Guidelines recommend risk stratification among patients with atherosclerotic cardiovascular disease (ASCVD) to identify “very high-risk ASCVD patients.” These patients have characteristics associated with a higher risk of recurrent ASCVD events; consequently, they derive a higher net absolute benefit from addition of ezetimibe and/or a proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) to statin therapy. From a clinical and payer’s perspective, we assessed the proportion of patients with ASCVD who will qualify as very high-risk based on the guideline criteria, their current lipid management, and how this will change with maximizing statin therapy and stepwise use of ezetimibe before consideration for a PCSK9i, as recommended by the 2018 cholesterol guideline

    Large-scale genome-wide association study of coronary artery disease in genetically diverse populations

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    We report a genome-wide association study (GWAS) of coronary artery disease (CAD) incorporating nearly a quarter of a million cases, in which existing studies are integrated with data from cohorts of white, Black and Hispanic individuals from the Million Veteran Program. We document near equivalent heritability of CAD across multiple ancestral groups, identify 95 novel loci, including nine on the X chromosome, detect eight loci of genome-wide significance in Black and Hispanic individuals, and demonstrate that two common haplotypes at the 9p21 locus are responsible for risk stratification in all populations except those of African origin, in which these haplotypes are virtually absent. Moreover, in the largest GWAS for angiographically derived coronary atherosclerosis performed to date, we find 15 loci of genome-wide significance that robustly overlap with established loci for clinical CAD. Phenome-wide association analyses of novel loci and polygenic risk scores (PRSs) augment signals related to insulin resistance, extend pleiotropic associations of these loci to include smoking and family history, and precisely document the markedly reduced transferability of existing PRSs to Black individuals. Downstream integrative analyses reinforce the critical roles of vascular endothelial, fibroblast, and smooth muscle cells in CAD susceptibility, but also point to a shared biology between atherosclerosis and oncogenesis. This study highlights the value of diverse populations in further characterizing the genetic architecture of CAD

    Beyond medication prescription as performance measures: optimal secondary prevention medication dosing after acute myocardial infarction

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    Objectives: The aim of this study was to examine the prescribing patterns of medications quantified by the performance measures for acute myocardial infarction (AMI). Background: Current performance measures for AMI are designed to improve quality by quantifying the use of evidence-based treatments. However, these measures only assess medication prescription. Whether patients receive optimal dosing of secondary prevention medications at the time of and after discharge after AMI is unknown. Methods: We assessed treatment doses of beta-blockers, statins, and angiotensin-converting enzyme inhibitors (ACEI)/angiotensin II receptor blockers (ARBs) at discharge and 12 months after AMI among 6,748 patients from 31 hospitals enrolled in 2 U.S. registries (2003 to 2008). Prescribed doses were categorized as none, low (87%) were prescribed some dose of each medication at discharge, although only 1 in 3 patients were prescribed these medications at goal doses. Of patients not discharged on goal doses, up-titration during follow-up occurred infrequently (approximately 25% of patients for each medication). At 12 months, goal doses of beta-blockers, statins, and ACEI/ARBs were achieved in only 12%, 26%, and 32% of eligible patients, respectively. After multivariable adjustment, prescription of goal dose at discharge was strongly associated with being at goal dose at follow-up: beta-blockers, adjusted odds ratio (OR): 6.08 (95% confidence interval [CI]: 3.70 to 10.01); statins, adjusted OR: 8.22 (95% CI: 6.20 to 10.90); ACEI/ARBs, adjusted OR: 5.80 (95% CI: 2.56 to 13.16); p < 0.001 for each. Conclusions: Although nearly all patients after an AMI are discharged on appropriate secondary prevention medications, dose increases occur infrequently, and most patients are prescribed doses below those with proven efficacy in clinical trials. Integration of dose intensity into performance measures might help improve the use of optimal medical therapy after AMI.Suzanne V.Arnold, John A.Spertus, Frederick A.Masoudi, Stacie L.Daugherty, Thomas M.Maddox, Yan Li ... et al

    Practice-level variation in use of recommended medications among outpatients with heart failure insights from the NCDR PINNACLE Program

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    The objective of this study is to examine practice-level variation in rates of guideline-recommended treatment for outpatients with heart failure and reduced ejection fraction, and to examine the association between treatment variation and practice site, independent of patient factors.Cardiology practices participating in the National Cardiovascular Disease Registry Practice Innovation and Clinical Excellence registry from July 2008 to December 2010 were evaluated. Practice rates of treatment with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and β-blockers and an optimal combined treatment measure were determined for patients with heart failure and reduced ejection fraction and no documented contraindications. Multivariable hierarchical regression models were adjusted for demographics, insurance status, and comorbidities. A median rate ratio was calculated for each therapy, which describes the likelihood that the treatment of a patient with given comorbidities would differ at 2 randomly selected practices. We identified 12 556 patients from 45 practices. The unadjusted practice-level prescription rates ranged from 44% to 100% for angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (median, 85%; interquartile range, 75%-89%), from 49% to 100% for β-blockers (median, 92%; interquartile range, 83%-95%), and from 37% to 100% for optimal combined treatment (median, 79%; interquartile range, 66%-85%). The adjusted median rate ratio was 1.11 (95% confidence interval, 1.08-1.18) for angiotensin-converting enzyme inhibitors/angiotensin receptor blockers therapy, 1.08 (95% confidence interval, 1.05-1.15) for β-blockers therapy, and 1.17 (1.13-1.26) for optimal combined treatment.Variation in the use of guideline-recommended medications for patients with heart failure and reduced ejection fraction exists in the outpatient setting. Addressing practice-level differences may be an important component of improving quality of care for patients with heart failure and reduced ejection fraction.Pamela N. Peterson, Paul S. Chan, John A. Spertus, Fengming Tang, Philip G. Jones, Justin A. Ezekowitz ... et al

    Association between diabetes mellitus and angina after acute myocardial infarction: Analysis of the TRIUMPH prospective cohort study

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    While patients with diabetes mellitus (DM) have more extensive coronary disease and worse survival after acute myocardial infarction (AMI) than patients without DM, data on whether they experience more angina are conflicting.We examined angina prevalence over the year following AMI among 3367 patients, including 1080 (32%) with DM, from 24 US hospitals enrolled in the TRIUMPH registry from 2005 to 2008.Patients with vs. without DM were more likely to be treated with antianginal medications both at discharge and over follow up. Despite more aggressive angina therapy, patients with vs. without DM had higher prevalence and severity of angina prior to AMI (49 vs. 43%, p = 0.001) and at each follow-up assessment, although rates of angina declined in both groups over time. In a hierarchical, multivariable, repeated-measures model that adjusted for multiple demographic and clinical factors including severity of coronary disease and in-hospital revascularization, DM was associated with a greater odds of angina over the 12 months of follow up; this association increased in magnitude over time (12-month OR 1.18, 95% CI 1.01-1.37; DM*time pinteraction = 0.008).Contrary to conventional wisdom, angina is more prevalent and more severe among patients with DM, both prior to and following AMI. This effect is amplified over time and independent of patient and treatment factors, including the presence of multivessel disease and coronary revascularization. This increased burden of angina may be due to more diffuse nature of coronary disease, more rapid progression of coronary disease over time, or greater myocardial demand among DM patients.Suzanne V Arnold, John A Spertus, Kasia J Lipska, Fengming Tang, Abhinav Goyal, Darren K McGuire ... et al
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