| 1. |
- Alehagen, Urban, et al.
(författare)
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Association of Copeptin and N-Terminal proBNP Concentrations With Risk of Cardiovascular Death in Older Patients With Symptoms of Heart Failure
- 2011
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Ingår i: JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION. - : Ama American Medical Association. - 0098-7484. ; 305:20, s. 2088-2095
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Tidskriftsartikel (refereegranskat)abstract
- Context Measurement of plasma concentrations of the biomarker copeptin may help identify patients with heart failure at high and low risk of mortality, although the value of copeptin measurement in elderly patients is not fully known. Objective To evaluate the association between plasma concentrations of copeptin, a surrogate marker of vasopressin, combined with concentrations of the N-terminal fragment of the precursor to B-type natriuretic peptide (NT-proBNP), and mortality in a cohort of elderly patients with symptoms of heart failure. Design, Setting, and Participants Primary health care population in Sweden enrolling 470 elderly patients with heart failure symptoms between January and December 1996. Clinical examination, echocardiography, and measurement of peptide concentrations were performed, with follow-up through December 2009. Main Outcome Measures All-cause mortality and cardiovascular mortality. Results After a median follow-up of 13 years, there were 226 deaths from all causes, including 146 deaths from cardiovascular causes. Increased concentration of copeptin was associated with increased risk of all-cause mortality (fourth quartile vs first quartile: 69.5% vs 38.5%, respectively; hazard ratio [HR], 2.04 [95% confidence interval {CI}, 1.38-3.02]) and cardiovascular mortality (fourth quartile vs first quartile: 46.6% vs 26.5%; HR, 1.94 [95% CI, 1.20-3.13]). The combination of elevated NT-proBNP concentrations and elevated copeptin concentrations also was associated with increased risk of all-cause mortality (copeptin fourth quartile: HR, 1.63 [95% CI, 1.08-2.47]; P=.01; NT-proBNP fourth quartile: HR, 3.17 [95% CI, 2.02-4.98]; Pandlt;.001). Using the 2 biomarkers simultaneously in the evaluation of cardiovascular mortality, there was a significant association for copeptin in the presence of NT-proBNP (log likelihood trend test, P=.048) and a significant association for NT-proBNP (fourth quartile: HR, 4.68 [95% CI 2.63-8.34]; Pandlt;.001). Conclusion Among elderly patients with symptoms of heart failure, elevated concentrations of copeptin and the combination of elevated concentrations of copeptin and NT-proBNP were associated with increased risk of all-cause mortality.
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| 2. |
- Alehagen, Urban, et al.
(författare)
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Combined measurement of copeptin, high-sensitivity troponin T, and N-terminal proBNP improves the identification of patients at risk of cardiovascular death
- 2012
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Ingår i: Cardiovascular Endocrinology. - 2162-688X. ; 1:4, s. 68-73
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: A multimarker strategy for the handling of patients with heart failure has been suggested in the literature. Therefore, the potential prognostic relevance of combined copeptin, high-sensitivity troponin T (HS-TnT), and N-terminal proBNP (NT-proBNP) measurement in plasma from elderly patients with symptoms of heart failure was evaluatedMethods: This study included 470 elderly patients (mean age 73 years) from a rural municipality with symptoms of heart failure. Clinical examination, echocardiography, and biomarker measurements were performed. All patients were followed for 13 years and all mortality was registered. Cardiovascular mortality was evaluated using Kaplan-Meier plots and multivariate Cox proportional hazard regression analyses.Results: Copeptin, HS-TnT, and NT-proBNP measurements provided independent prognostic information in a multivariate setting over 5 years (hazard ratio, HR: 3.66; 95% confidence interval, CI 1.27-10.53, HR: 2.52; 95% CI 1.20-5.28, HR: 2.73; 95% CI 1.19-6.26, respectively). Also, the group with all three biomarkers below cut-off values had a low risk for cardiovascular death (1.8% of the patients in this group died in the 5-year follow-up period). In the 13-year follow-up, combined copeptin and HS-TnT measurement did not provide independent prognostic information.Conclusion: Combined copeptin, HS-TnT, and NT-proBNP plasma measurements provide prognostic information on cardiovascular mortality that is superior to single biomarker use.
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| 3. |
- Alehagen, Urban, et al.
(författare)
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Pro-A-Type Natriuretic Peptide, Proadrenomedullin, and N-Terminal Pro-B-Type Natriuretic Peptide Used in a Multimarker Strategy in Primary Health Care in Risk Assessment of Patients With Symptoms of Heart Failure
- 2013
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Ingår i: Journal of Cardiac Failure. - : Elsevier. - 1071-9164 .- 1532-8414. ; 19:1, s. 31-39
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Use of new biomarkers in the handling of heart failure patients has been advocated in the literature, but most often in hospital-based populations. Therefore, we wanted to evaluate whether plasma measurement of N-terminal pro B-type natriuretic peptide (NT-proBNP), midregional pro A-type natriuretic peptide (MR-proANP), and midregional proadrenomedullin (MR-proADM), individually or combined, gives prognostic information regarding cardiovascular and all-cause mortality that could motivate use in elderly patients presenting with symptoms suggestive of heart failure in primary health care. less thanbrgreater than less thanbrgreater thanMethods and Results: The study included 470 elderly patients (mean age 73 years) with symptoms of heart failure in primary health care. All participants underwent clinical examination, 2-dimenstional echocardiography, and plasma measurement of the 3 propeptides and were followed for 13 years. All mortality was registered during the follow-up period. The 4th quartiles of the biomarkers were applied as cutoff values. NT-proBNP exhibited the strongest prognostic information with andgt;4-fold increased risk for cardiovascular mortality within 5 years. For all-cause mortality MR-proADM exhibited almost 2-fold and NT-proBNP 3-fold increased risk within 5 years. In the 5-13-year perspective, NT-proBNP and MR-proANP showed significant and independent cardiovascular prognostic information. NT-proBNP and MR-proADM showed significant prognostic information regarding all-cause mortality during the same time. In those with ejection fraction (EF) andlt;40%, MR-proADM exhibited almost 5-fold increased risk of cardiovascular mortality with 5 years, whereas in those with EF andgt;50% NT-proBNP exhibited andgt;3-fold increased risk if analyzed as the only biomarker in the model. If instead the biomarkers were all below the cutoff value, the patients had a highly reduced mortality risk, which also could influence the handling of patients. less thanbrgreater than less thanbrgreater thanConclusions: The 3 biomarkers could be integrated in a multimarker strategy for use in primary health care. (J Cardiac Fail 2013;19:31-39)
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| 4. |
- Alehagen, Urban, et al.
(författare)
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Prognostic Assessment of Elderly Patients with Symptoms of Heart Failure by Combining High-Sensitivity Troponin T and N-Terminal Pro-B-Type Natriuretic Peptide Measurements
- 2010
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Ingår i: CLINICAL CHEMISTRY. - : American Association for Clinical Chemistry; 1999. - 0009-9147 .- 1530-8561. ; 56:11, s. 1718-1724
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a useful biomarker in heart failure assessment, whereas measurement of cardiac troponin is central in the diagnosis of patients with acute coronary syndromes. This report examined the prognostic use of combining high-sensitivity cardiac troponin T (hs-cTnT) and NT-proBNP measurements in elderly patients presenting to a primary care center with symptoms associated with heart failure. METHODS: A total of 470 elderly patients (age range 65-86 years) presenting with symptoms of heart failure were recruited from primary healthcare. In addition to clinical examination and echocardiography, hs-cTnT and NT-proBNP plasma concentrations were measured. All patients were followed for 10 years, and cardiovascular mortality was registered. RESULTS: By use of the hs-cTnT assay, 80.4% of the population had plasma concentrations above the lower detection limit of the assay. Of those displaying a plasma concentration of hs-cTnT andgt;99th percentile of a healthy population, 43% also had an NT-proBNP concentration in the fourth quartile (andgt;507 ng/L). In the multivariate analysis, we observed a 2.5-fold increased risk for cardiovascular mortality in individuals with a plasma NT-proBNP concentration andgt;507 ng/L (P andlt; 0.0001). Conversely, patients with hs-cTnT andgt;99th percentile displayed an approximately 2-fold increased risk for cardiovascular mortality (P = 0.0002). Combining the 2 biomarkers, NT-proBNP concentrations andgt;507 ng/L with hs-cTnT andgt;99th percentile increased the risk 3-fold, even after adjustment for clinical variables such as age, sex, impaired estimated glomerular filtration rate, and anemia (P andlt; 0.0001). CONCLUSIONS: hs-cTnT and NT-proBNP measurements combined provide better prognostic information than using either biomarker separately in elderly patients with symptoms associated with heart failure.
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| 5. |
- Hunter, Ingrid, et al.
(författare)
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N-Terminal Pro-Atrial Natriuretic Peptide Measurement in Plasma Suggests Covalent Modification
- 2011
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Ingår i: Clinical Chemistry. - : American Association for Clinical Chemistry. - 0009-9147 .- 1530-8561. ; 57:9, s. 1327-1330
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The N-terminal fragment of cardiac-derived pro-B-type natriuretic peptide is a glycosylated polypeptide. It is unknown whether N-terminal proatrial natriuretic peptide (proANP) fragments are also covalently modified. We therefore evaluated the clinical performance of 2 distinctly different proANP assays on clinical outcome. METHODS: We examined 474 elderly patients with symptoms of heart failure presenting in a primary healthcare setting. Samples were analyzed with an automated immunoluminometric midregion proANP (MR-proANP) assay and a new processing-independent assay (PIA) developed in our laboratory. The results were compared with Bland-Altman plots, and clinical performance was assessed by generating ROC curves for different clinical outcomes. RESULTS: Despite linear regression results indicating a good correlation (r = 0.85; P less than 0.0001), the PIA measured considerably more proANP than the MR-proANP assay (mean difference, 663 pmol/L; SD, 478 pmol/L). In contrast, the clinical performances of the 2 assays [as assessed by the area under the ROC curve (AUC)] in detecting left ventricular dysfunction were similar [proANP PIA, 0.71 (95% CI, 0.63-0.79); MR-proANP assay, 0.74 (95% CI, 0.66-0.81); P = 0.32]. The prognostic ability to report cardiovascular mortality during a 10-year follow-up revealed AUC values of 0.66 (95% CI, 0.60-0.71) for the proANP PIA and 0.69 (95% CI, 0.63-0.74) for the MR-proANP assay (P = 0.08, for comparing the 2 assays). CONCLUSIONS: Our data suggest that N-terminal proANP fragments in patient plasma differ from the calibrator peptides used but that the difference does not affect ROC curves in an elderly cohort of patients with mild to moderate heart failure. We suggest that human N-terminal proANP fragments can be covalently modified.
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| 6. |
- Peter Goetze, Jens, et al.
(författare)
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Impact of Epitope Specificity and Precursor Maturation in Pro-B-Type Natriuretic Peptide Measurement
- 2008
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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 54:11, s. 1780-1787
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cardiac-derived natriuretic peptides are sensitive plasma markers of cardiac dysfunction. Recent reports have disclosed a more complex molecular heterogeneity of B-type natriuretic peptide precursor (proBNP)-derived peptides than previously Suggested. In this study, we examined the impact of epitope specificity and precursor maturation oil plasma measurement of proBNP-derived peptides. Methods: We compared 2 assays, N-terminal proBNP and proBNP 1-76, in a randomly collected set of human plasma specimens (n = 370). Additionally, we evaluated the clinical performance of 4 assays with different epitope specificities in a cohort of elderly patients presenting with symptoms associated with heart failure (n = 415). Results: Comparison of N-terminal proBNP with proBNP 1-76 measurement in plasma revealed a high correlation on regression analysis (r(2) = 0.91, p < 0.0001). Nevertheless, the proBNP 1-76 assay measured lower concentrations in the high range than the N-terminal proBNP assay. Correlations between assay measurements in a clinical setting were comparable for all the assays (r(2) approximately 0.57-0.83), and ROC analyses revealed area-under-the-curve values ranging between 0.77 and 0.81 for identifying reduced left ventricular ejection fraction. In parallel, all assays displayed comparable abilities in predicting long-term mortality. Conclusions: Our results reveal marked assay differences in analytical assay comparison, contrasting the overall comparable clinical performance in cardiovascular diagnostics or prognosis in the elderly.
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| 7. |
- Dong, Bin, 1984, et al.
(författare)
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Optimization and Realization of Quadruple-ridge Flared Horn with New Spline-defined Profiles as a High-efficiency Feed over 4.6–24 GHz
- 2019
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 67:1, s. 585-590
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present a new optimization and realization of a quadruple-ridge flared horn (QRFH) as a feed for reflector antennas of the Square Kilometre Array (SKA) project. The QRFH has been numerically optimized by spline-defined profiles for both the ridges and the horn sidewall, with a conical cavity in the back-short for maximum aperture efficiency. The final aperture efficiency better than (for horizontal polarization) or around (for vertical polarization) 78% over 4.6–8 GHz, 70% over 8–15 GHz, 65% over 15–20 GHz and 60% over 20–24 GHz in the SKA offset-Gregorian dual-reflector antenna has been achieved. The realization of the horn has been carried out carefully by applying several new mechanical design solutions in order to guarantee the accurate positioning of the ridges, the feeding pins and a good electrical contact. The measured S11 is mostly better than -10 dB and the predicted aperture efficiency based on the measured far field patterns agrees well with the simulated result. System performance, such as the sensitivity and system noise temperature, are also estimated and presented.
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| 8. |
- Flygare, Jonas, 1988, et al.
(författare)
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Beam pattern measurement on offset Gregorian reflector mounted with a wideband room temperature receiver for the Square Kilometre Array
- 2018
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Ingår i: 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting (APSURSI2018). - 9781538671023 ; APSURSI 2018, s. 1759-1760
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Konferensbidrag (refereegranskat)abstract
- We present measured on-dish beam patterns for a room temperature spline-profile quad-ridge flared horn (QRFH) feed designed for the Square Kilometre Array (SKA) Band 1 covering 350-1050 MHz. The feed and LNA package has been mounted on the offset Gregorian SKA precursor prototype telescope, Dish Verification Antenna 1 (DVA-1) located at the Dominion Radio Astrophysical Observatory (DRAO) near Penticton, British Columbia, Canada. Telescope beam pattern cuts are measured by sweeping over the sun and adding corrections for the solar disk size, elevation and aperture efficiency. Sensitivity calculated with measured receiver noise show good agreement with the predicted performance.
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| 9. |
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