Rotation is ubiquitous at each step of stellar evolution, from star formation to the final stages, and it affects the course of evolution, the timescales and nucleosynthesis. Stellar rotation is also ...an essential prerequisite for the occurrence of Gamma-Ray Bursts.In this book the author thoroughly examines the basic mechanical and thermal effects of rotation, their influence on mass loss by stellar winds, the effects of differential rotation and its associated instabilities, the relation with magnetic fields and the evolution of the internal and surface rotation. Further, he discusses the numerous observational signatures of rotational effects obtained from spectroscopy and interferometric observations, as well as from chemical abundance determinations, helioseismology and asteroseismology, etc.On an introductory level, this book presents in a didactical way the basic concepts of stellar structure and evolution in "track 1" chapters. The other more specialized chapters form an advanced course on the graduate level and will further serve as a valuable reference work for professional astrophysicists.
.
Objective. To assess the utility of B‐type natriuretic peptide (BNP) and C‐terminal‐pro‐endothelin‐1 (CT‐proET‐1) to predict a severely impaired peak oxygen consumption (peak VO2, < 14 mL kg−1 ...min−1) in patients referred for cardiopulmonary exercise testing.
Design. Cross‐sectional study.
Setting. Tertiary care center.
Methods. Peak VO2, BNP and CT‐proET‐1 were assessed in 141 consecutive patients referred for cardiopulmonary exercise testing.
Results. B‐type natriuretic peptide median (interquartile range) 48 (38–319) vs. 33 (15–86) pg mL−1; P = 0.002 and CT‐proET‐1 87 (76–95) vs. 60 (52–74) pmol L−1; P < 0.001 were higher in patients with a peak VO2 < 14 mL kg−1 min−1 (n = 30) than in those with a peak VO2 ≥ 14 mL kg−1 min−1 (n = 111). CT‐pro‐ET‐1 had a higher area under the receiver‐operator‐characteristics curve (AUC) to predict a peak VO2 < 14 mL kg−1 min−1 than BNP (0.79 vs. 0.68; P = 0.04). The optimal BNP cut‐off of 37.2 pg mL−1 had a sensitivity of 80% and a specificity of 56%. The optimal CT‐proET‐1 cut‐off of 74.4 pmol L−1 had a sensitivity of 80% and specificity of 76%. A five‐item score composed of body mass index, diabetes, forced expiratory volume within the first second, alveolo–arterial oxygen pressure difference, and BNP had an AUC of 0.88 to predict a peak VO2 < 14 mL kg−1 min−1. Adding CT‐proET‐1 to the score resulted in an AUC of 0.92.
Conclusions. C‐terminal‐pro‐endothelin‐1 is superior to BNP for the prediction of a peak VO2 < 14 mL kg−1 min−1 in patients referred for CPET. A score incorporating body mass index, diabetes status, spirometry, blood gases, BNP and CT‐proET‐1 improves the prediction of a peak VO2 < 14 mL kg−1 min−1 based on single biomarkers.
Maximal exercise capacity expressed as metabolic equivalents (METs) is rarely directly measured (measured METs; mMETs) but estimated from maximal workload (estimated METs; eMETs). We assessed the ...accuracy of predicting mMETs by eMETs in asymptomatic subjects. Thirty-four healthy volunteers without cardiovascular risk factors (controls) and 90 patients with at least one risk factor underwent cardiopulmonary exercise testing using individualized treadmill ramp protocols. The equation of the American College of Sports Medicine (ACSM) was employed to calculate eMETs. Despite a close correlation between eMETs and mMETs (patients: r = 0.82, controls: r = 0.88; p < 0.001 for both), eMETs were higher than mMETs in both patients 11.7 (8.9 - 13.4) vs. 8.2 (7.0 - 10.6) METs; p < 0.001 and controls 17.0 (16.2 - 18.2) vs. 15.6 (14.2 - 17.0) METs; p < 0.001. The absolute 2.5 (1.6 - 3.7) vs. 1.3 (0.9 - 2.1) METs; p < 0.001 and the relative 28 (19 - 47) vs. 9 (6 - 14) %; p < 0.001 difference between eMETs and mMETs was higher in patients. In patients, ratio limits of agreement of 1.33 (*/ divided by 1.40) between eMETs and mMETs were obtained, whereas the ratio limits of agreement were 1.09 (*/ divided by 1.13) in controls. The ACSM equation is associated with a significant overestimation of mMETs in young and fit subjects, which is markedly more pronounced in older and less fit subjects with cardiovascular risk factors.
Background Incidence, predictors, and prognostic impact of worsening renal function (WRF) in elderly patients with chronic heart failure (HF) undergoing intensive contemporary medical therapy are ...unknown. Methods and Results In 566 patients (age 77 ± 8 years) included in the TIME-CHF, serum creatinine (sCr) was repeatedly measured up to 6 months. Worsening renal function was classified as increase in sCr by 0.2 to 0.3 (WRFI), 0.3 to 0.5 (WRFII), or ≥0.5 mg/dL (WRFIII) within the first 6 months. Outcome events were assessed for 18 months. Results The incidence of WRF I, II, and III was 12%, 19%, and 22%, respectively. Worsening renal function III was associated with increased mortality (hazard ratio 1.98 95% CI 1.27-3.07, P = .002 vs no WRF), whereas WRF I/II was not. History of renal failure, spironolactone treatment, higher baseline dose, and higher maximal increase in loop diuretic dose were independently associated with the occurrence of WRF III, whereas angiotensin-converting enzyme inhibitor, angiotensin receptor blocker, and β-blocker use and allocation to N-terminal pro–B-type natriuretic peptide–guided management were not. Worsening renal function III was an independent predictor of death, death or hospitalization, and death or HF hospitalization also after adjusting for baseline characteristics. Conclusions One fifth of elderly patients with chronic HF experienced WRF III on 6-month intensive HF treatment. These patients had higher mortality, whereas patients with smaller sCr rises did not. Occurrence of WRF III was associated with high doses of loop diuretics and spironolactone use but not with other treatments.
Background Contemporary heart failure (HF) patients are elderly and have a high rate of early rehospitalization or death, resulting in a high burden for both the patients and the health care system. ...Prior studies were focused on younger and less well-characterized patients. We aimed to identify predictors of early hospital readmission and death in elderly patients with HF. Methods Patients with chronic HF taking part in the TIME-CHF study (n = 614, age 77 ± 8 years, 41% female, left ventricular ejection fraction 35% ± 13%) were evaluated with respect to predictors of hospital readmission or death 30 and 90 days after inclusion. Demographic, clinical, laboratory, echocardiographic, and social variables were obtained at baseline and included in a multivariable logistic regression analysis to identify predictors of early events. Results The rate of hospital readmission or death was high at 30 (11%) and 90 days (26%). The reason for hospitalization was HF in 33%, other cardiovascular in 32%, and noncardiovascular in 45% of the cases, respectively. Predictors of readmission or death at 30 days were angina, lower systolic blood pressure, anemia, more extensive edema, higher creatinine levels, and dry cough; and at 90 days were coronary artery disease, prior pacemaker implantation, high jugular venous pressure, pulmonary rales, prior abdominal surgery, older age, and depressive symptoms. Conclusions Early hospital readmission or death was frequent among elderly HF patients. A very large proportion of readmissions were due to noncardiovascular causes. In addition to clinical signs of HF, comorbidities are important predictors of early events in elderly HF patients.
Background:
The overwhelming majority of patients with stress cardiomyopathy (SC) are postmenopausal women, suggesting an important pathophysiologic role of the female sex hormones. Preliminary data ...suggest that myocardial stunning might be provoked by estrogen deficiency.
Hypothesis:
We hypothesized that, compared with age‐ and gender‐matched patients with myocardial infarction (MI) or patients with normal coronary arteries, patients with SC would exhibit altered levels of sex hormones. Furthermore, we aimed to describe the clinical course and the pattern of sex hormones of the SC patients during long‐term follow‐up.
Methods:
Blood samples obtained on hospital admission were analyzed for estradiol (E2), progesterone (P), luteinizing hormone (LH), and follicle‐stimulating hormone (FSH) in women with SC (n = 17), age‐matched women with acute MI (n = 16), and women with normal coronary arteries (n = 15). Six years after the initial event, SC patients underwent a clinical and echocardiographic follow‐up and reassessment of sex hormones.
Results:
Estrogen concentrations at hospital admission were significantly higher in the SC group compared with the MI and the control groups, with no difference in P, FSH, and LH concentrations. Follow‐up E2 after 6 years in SC patients was lower than during the acute SC episode. Follow‐up P in these patients was lower than P in the MI and control groups during the acute event, with a similar trend for E2. After a median follow‐up of 6.4 years, 1 sudden cardiac death occurred and 2 patients suffered from SC recurrence.
Conclusions:
During the acute event, E2 concentrations are elevated in postmenopausal SC patients compared with women with acute MI or with normal coronary arteries. The higher E2 concentrations might have exerted atheroprotective effects and thus diverted the stress response to SC rather than MI. Recurrence and/or sudden cardiac death remains a potential risk of SC. Clin. Cardiol. 2012 DOI: 10.1002/clc.21986
Roman Brenner, MD, and Daniel Weilenmann, MD, contributed equally to this work and should be considered first authors.
The authors have no funding, financial relationships, or conflicts of interest to disclose.
Aims
Heart failure (HF) management is complicated by difficulties in clinical assessment. Biomarkers may help guide HF management, but the correspondence between clinical evaluation and biomarker ...serum levels has hardly been studied. We investigated the correlation between biomarkers and clinical signs and symptoms, the influence of patient characteristics and comorbidities on New York Heart Association (NYHA) classification and the effect of using biomarkers on clinical evaluation.
Methods and results
This post-hoc analysis comprised 622 patients (77 ± 8 years, 76 % NYHA class ≥3, 80 % LVEF ≤45 %) participating in TIME-CHF, randomising patients to either NT-proBNP-guided or symptom-guided therapy. Biomarker measurements and clinical evaluation were performed at baseline and after 1, 3, 6, 12 and 18 months. NT-proBNP, GDF-15, hs-TnT and to a lesser extent hs-CRP and cystatin-C were weakly correlated to NYHA, oedema, jugular vein distension and orthopnoea (ρ-range: 0.12–0.33;
p
< 0.01). NT-proBNP correlated more strongly to NYHA class in the NT-proBNP-guided group compared with the symptom-guided group. NYHA class was significantly influenced by age, body mass index, anaemia, and the presence of two or more comorbidities.
Conclusion
In HF, biomarkers correlate only weakly with clinical signs and symptoms. NYHA classification is influenced by several comorbidities and patient characteristics. Clinical judgement seems to be influenced by a clinician’s awareness of NT-proBNP concentrations.
PDF
