165 research outputs found
Theoretical determination of lifetimes of metastable states in Sc III and Y III
Lifetimes of the first two metastable states in Sc^{2+} and Y^{2+} are
determined using the relativistic coupled-cluster theory. There is a
considerable interest in studying the electron correlation effects in these
ions as though their electronic configurations are similar to the neutral
alkali atoms, their structures are very different from the latter. We have made
a comparative study of the correlation trends between the above doubly ionized
systems with their corresponding neutral and singly ionized iso-electronic
systems. The lifetimes of the excited states of these ions are very important
in the field of astrophysics, especially for the study of post-main sequence
evolution of the cool giant stars.Comment: 13 pages, 1 figure and 5 table
Abundances of neutron-capture elements in the Hot Extreme-Helium Stars V1920 Cygni and HD 124448
Analysis of HST STIS ultraviolet spectra of two hot extreme helium stars
(EHes): V1920 Cyg and HD 124448 provide the first measurements of abundances of
neutron-capture elements for EHes. Although the two stars have similar
abundances for elements up through the iron-group, they differ strikingly in
their abundances of heavier elements: V1920 Cyg is enriched by a factor of 30
in light neutron-capture elements (Y/Fe, Zr/Fe) relative to HD 124448. These
differences in abundances of neutron-capture elements among EHes mirrors that
exhibited by the RCrB stars, and is evidence supporting the view that there is
an evolutionary connection between these two groups of hydrogen-deficient
stars. Also, the abundances of Y and Zr in V1920 Cyg provide evidence that at
least one EHe star went through a s-process synthesis episode in its earlier
evolution.Comment: 4 pages (embedded figure and table), accepted for publication in ApJ
Letter
Utility of the ACC/AHA Lesion Classification to Predict Outcomes After Contemporary DES Treatment:Individual Patient Data Pooled Analysis From 7 Randomized Trials
BACKGROUND: Use of the modified American College of Cardiology (ACC)/American Heart Association (AHA) lesion classification as a prognostic tool to predict shortâ and longâterm clinical outcomes after percutaneous coronary intervention in the modern drugâeluting stent era is uncertain. METHODS AND RESULTS: Patientâlevel data from 7 prospective, randomized trials were pooled. Clinical outcomes of patients undergoing single lesion percutaneous coronary intervention with secondâgeneration drugâeluting stent were analyzed according to modified ACC/AHA lesion class. The primary end point was target lesion failure (TLF: composite of cardiac death, target vessel myocardial infarction, or ischemiaâdriven target lesion revascularization). Clinical outcomes to 5âyears were compared between patients treated for noncomplex (class A/B1) versus complex (class B2/C) lesions. Eight thousand five hundred sixteen patients (age 63.1±10.8âyears, 70.5% male) were analyzed. Lesions were classified as A, B1, B2, and C in 7.9%, 28.5%, 33.7%, and 30.0% of cases, respectively. Target lesion failure was higher in patients undergoing percutaneous coronary intervention of complex versus noncomplex lesions at 30âdays (2.0% versus 1.1%, P=0.004), at 1âyear (4.6% versus 3.0%, P=0.0005), and at 5âyears (12.4% versus 9.2%, P=0.0001). By multivariable analysis, treatment of ACC/AHA class B2/C lesions was significantly associated with higher rate of 5âyear target lesion failure (adjusted hazard ratio, 1.39 [95% CI, 1.17â1.64], P=0.0001) driven by significantly higher rates of target vessel myocardial infarction and ischemiaâdriven target lesion revascularization. CONCLUSIONS: In this pooled largeâscale analysis, treating complex compared with noncomplex lesions according to the modified ACC/AHA classification with secondâgeneration drugâeluting stent was associated with worse 5âyear clinical outcomes. This historical classification system may be useful in the contemporary era for predicting early and late outcomes following percutaneous coronary intervention
Pathophysiology of Takotsubo syndrome - a joint scientific statement from the Heart Failure Association Takotsubo Syndrome Study Group and Myocardial Function Working Group of the European Society of Cardiology - Part 1 : overview and the central role for catecholamines and sympathetic nervous system
Acknowledgements S.H. acknowledges the support from the Netherlands Cardiovascular Research Initiative, an initiative with support of the Dutch Heart Foundation, CVON2016-Early HFPEF, 2015-10, and CVON She-PREDICTS, grant 2017-21, CVON-Arena-PRIME, European Union Commissionâs Seventh Framework programme under grant agreement n. 305507 (HOMAGE) and n. 602904 (FIBROTAR-GETS). D.D. acknowledges support from the British Heart Foundation grants PG/15/108/31928 and FS/16/39/32174, the Josephine Lansdell British Medical Association 2015Award and Tenovus Scotland, G13.10. A.R.L. is supported by the Leducq Foundation Cardio-Oncology Network. Conflict of interest: none declaredPeer reviewedPublisher PD
Pathophysiology of Takotsubo syndrome - a joint scientific statement from the Heart Failure Association Takotsubo Syndrome Study Group and Myocardial Function Working Group of the European Society of Cardiology - Part 2: vascular pathophysiology, gender and sex hormones, genetics, chronic cardiovascular problems and clinical implications
While the first part of the scientific statement on the pathophysiology of Takotsubo syndrome was focused on catecholamines and the sympathetic nervous system, in the second part we focus on the vascular pathophysiology including coronary and systemic vascular responses, the role of the central and peripheral nervous systems during the acute phase and abnormalities in the subacute phase, the gender differences and integrated effects of sex hormones, genetics of Takotsubo syndrome including insights from microRNA studies and inducible pluripotent stem cell models of Takotsubo syndrome. We then discuss the chronic abnormalities of cardiovascular physiology in survivors, the limitations of current clinical and preclinical studies, the implications of the knowledge of pathophysiology for clinical management and future perspectives and directions of research
New-Onset Atrial Fibrillation After PCI or CABG for Left Main Disease: The EXCEL Trial
Background: There is limited information on the incidence and prognostic impact of new-onset atrial fibrillation (NOAF) following percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for left main coronary artery disease (LMCAD). Objectives: This study sought to determine the incidence of NOAF following PCI and CABG for LMCAD and its effect on 3-year cardiovascular outcomes. Methods: In the EXCEL (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial, 1,905 patients with LMCAD and low or intermediate SYNTAX scores were randomized to PCI with everolimus-eluting stents versus CABG. Outcomes were analyzed according to the development of NOAF during the initial hospitalization following revascularization. Results: Among 1,812 patients without atrial fibrillation on presentation, NOAF developed at a mean of 2.7 ± 2.5 days after revascularization in 162 patients (8.9%), including 161 of 893 (18.0%) CABG-treated patients and 1 of 919 (0.1%) PCI-treated patients (p < 0.0001). Older age, greater body mass index, and reduced left ventricular ejection fraction were independent predictors of NOAF in patients undergoing CABG. Patients with versus without NOAF had a significantly longer duration of hospitalization, were more likely to be discharged on anticoagulant therapy, and had an increased 30-day rate of Thrombolysis In Myocardial Infarction major or minor bleeding (14.2% vs. 5.5%; p < 0.0001). By multivariable analysis, NOAF after CABG was an independent predictor of 3-year stroke (6.6% vs. 2.4%; adjusted hazard ratio [HR]: 4.19; 95% confidence interval [CI]: 1.74 to 10.11; p = 0.001), death (11.4% vs. 4.3%; adjusted HR: 3.02; 95% CI: 1.60 to 5.70; p = 0.0006), and the primary composite endpoint of death, MI, or stroke (22.6% vs. 12.8%; adjusted HR: 2.13; 95% CI: 1.39 to 3.25; p = 0.0004). Conclusions: In patients with LMCAD undergoing revascularization in the EXCEL trial, NOAF was common after CABG but extremely rare after PCI. The development of NOAF was strongly associated with subsequent death and stroke in CABG-treated patients. Further studies are warranted to determine whether prophylactic strategies to prevent or treat atrial fibrillation may improve prognosis in patients with LMCAD who are undergoing CABG. (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularizatio
Self-perceived psychological stress and ischemic stroke: a case-control study
<p>Abstract</p> <p>Background</p> <p>A growing body of evidence suggests that psychological stress contributes to coronary artery disease. However, associations between stress and stroke are less clear. In this study, we investigated the possible association between ischemic stroke and self-perceived psychological stress, as measured by a single-item questionnaire, previously reported to be associated with myocardial infarction.</p> <p>Methods</p> <p>In the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS), 600 consecutive patients with acute ischemic stroke (aged 18 to 69 years) and 600 age-matched and sex-matched population controls were recruited. Ischemic stroke subtype was determined according to Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Self-perceived psychological stress preceding stroke was assessed retrospectively using a single-item questionnaire.</p> <p>Results</p> <p>Permanent self-perceived psychological stress during the last year or longer was independently associated with overall ischemic stroke (multivariate adjusted odds ratio (OR) 3.49, 95% confidence interval (CI) 2.06 to 5.93). Analyses by stroke subtype showed that this association was present for large vessel disease (OR 3.91, 95% CI 1.58 to 9.67), small vessel disease (OR 3.20, 95% CI 1.64 to 6.24), and cryptogenic stroke (OR 4.03, 95% CI 2.34 to 6.95), but not for cardioembolic stroke (OR 1.48, 95% CI 0.64 to 3.39).</p> <p>Conclusion</p> <p>In this case-control study, we found an independent association between self-perceived psychological stress and ischemic stroke. A novel finding was that this association differed by ischemic stroke subtype. Our results emphasize the need for further prospective studies addressing the potential role for psychological stress as a risk factor for ischemic stroke. In such studies ischemic stroke subtypes should be taken into consideration.</p
B-Type Natriuretic Peptide Assessment in Patients Undergoing Revascularization for Left Main Coronary Artery Disease
BACKGROUND: Elevated B-type natriuretic peptide (BNP) is reflective of impaired cardiac function and is associated with worse prognosis among patients with coronary artery disease (CAD). We sought to assess the association between baseline BNP, adverse outcomes, and the relative efficacy of percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG) in patients with left main CAD. METHODS: The EXCEL trial (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) randomized patients with left main CAD and low or intermediate SYNTAX scores (Synergy Between PCI With TAXUS and Cardiac Surgery) to PCI with everolimus-eluting stents versus CABG. The primary end point was the composite of all-cause death, myocardial infarction, or stroke. We used multivariable Cox proportional hazards regression to assess the associations between normal versus elevated BNP (â„100 pg/mL), randomized treatment, and the 3-year risk of adverse events. RESULTS: BNP at baseline was elevated in 410 of 1037 (39.5%) patients enrolled in EXCEL. Patients with elevated BNP levels were older and more frequently had additional cardiovascular risk factors and lower left ventricular ejection fraction than those with normal BNP, but had similar SYNTAX scores. Patients with elevated BNP had significantly higher 3-year rates of the primary end point (18.6% versus 11.7%; adjusted hazard ratio [HR], 1.62; 95% confidence interval [CI], 1.16-2.28; P=0.005) and higher mortality (11.5% versus 3.9%; adjusted HR, 2.49; 95% CI, 1.48-4.19; P=0.0006), both from cardiovascular and noncardiovascular causes. In contrast, there were no significant differences in the risks of myocardial infarction, stroke, ischemia-driven revascularization, stent thrombosis, graft occlusion, or major bleeding. A significant interaction ( Pinteraction=0.03) was present between elevated versus normal BNP and treatment with PCI versus CABG for the adjusted risk of the primary composite end point at 3 years among patients with elevated BNP (adjusted HR for PCI versus CABG, 1.54; 95% CI, 0.96-2.47) versus normal BNP (adjusted HR, 0.74; 95% CI, 0.46-1.20). This interaction was stronger when log(BNP) was modeled as a continuous variable ( Pinteraction=0.002). CONCLUSIONS: In the EXCEL trial, elevated baseline BNP levels in patients with left main CAD undergoing revascularization were independently associated with long-term mortality but not nonfatal adverse ischemic or bleeding events. The relative long-term outcomes after PCI versus CABG for revascularization of left main CAD may be conditioned by the baseline BNP level. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01205776
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