| 1. |
- James, Stefan K., 1964-, et al.
(author)
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Troponin-T and N-terminal pro-B-type natriuretic peptide predict mortality benefit from coronary revascularization in acute coronary syndromes : a GUSTO-IV substudy
- 2006
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In: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097 .- 1558-3597. ; 48:6, s. 1146-1154
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Journal article (peer-reviewed)abstract
- OBJECTIVES: This study was designed to evaluate biomarkers for selection of patients with non-ST-segment elevation acute coronary syndromes (ACS) that derive mortality benefit from revascularization. BACKGROUND: Biomarkers are essential for identification of patients at increased risk, which may be reduced by revascularization. METHODS: During the initial 30 days, 2,340 patients of 7,800 (30%) with non-ST-segment elevation ACS in the GUSTO (Global Utilization of Strategies To open Occluded arteries)-IV trial underwent coronary revascularization. The 1-year mortality was calculated in 30-day survivors stratified by status of revascularization and levels of biomarkers. A propensity score for receiving revascularization was constructed and included in a survival analysis that also included the time point of revascularization as a time-dependent covariate. RESULTS: Elevation of troponin-T or N-terminal pro-B-type natriuretic peptide (NT-proBNP) was associated with a high mortality. In patients with either or both of these markers elevated, a lower mortality following revascularization was observed. In contrast, patients without elevation of these markers had low 1-year mortality without any reduction in mortality following revascularization. In fact, in patients with normal levels of both troponin-T and NT-proBNP, a significant increase in 1-year mortality after revascularization was observed. Elevation of C-reactive protein, interleukin-6, creatinine clearance, and ST-segment depression was also related to a higher mortality. However, independent of these markers, mortality was lower after revascularization. CONCLUSIONS: Markers of troponin-T and NT-proBNP not only assist in risk stratification of patients with non-ST-segment elevation ACS but also appear to identify patients who have a reduced mortality associated with early coronary revascularization.
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| 2. |
- James, Stefan, 1964-, et al.
(author)
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The antibody configurations of cardiac troponin I assays may determine their clinical performance
- 2006
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In: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 52:5, s. 832-837
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Journal article (peer-reviewed)abstract
- BACKGROUND: Previous studies have shown superior clinical performance of the cardiac troponin I (cTnI) assay from Beckman-Coulter Diagnostics. This assay had a unique combination of monoclonal antibodies with 2 monoclonal antibodies directed against epitopes near the NH(2) terminus of the heart-specific region of troponin I. The approach has been adopted by the new cTnI assay from Abbott Diagnostics. The aim of our study was to investigate whether this approach affects the clinical performance of cTnI assays. METHODS: Cardiac troponin concentrations were measured in a random sample of patients with unstable coronary artery disease included in the GUSTO IV trial (n = 696) by the AccuTnI (Beckman-Coulter Diagnostics), Architect cTnI (Abbott Diagnostics), Immulite 2500 cTnI (Diagnostics Products Corporation), and Elecsys 2010 cTnT (Roche Diagnostics) assays and related to the 1-year mortality. The primary cutoff concentrations were based on the 99th percentile upper reference limits and an imprecision (CV) < or =10%. RESULTS: The sensitivities of the AccuTnI and Architect cTnI assays in identifying patients who died within 1 year were equal and were significantly higher (P <0.05) than those of the Immulite 2500 cTnI and the Elecsys cTnT assays. The concordance between the AccuTnI and Architect cTnI assays was 97%, but concordances between the Architect cTnI and the Elecsys cTnT assays were 89%-92% with more at-risk patients (P <0.01 to P <0.001) identified by the Architect cTnI assay. CONCLUSIONS: The Architect cTnI assay has clinical performance similar to that of the AccuTnI, probably as a result of the inclusion of a monoclonal antibody against troponin I epitope 41-49 in the assay
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| 3. |
- Jernberg, Tomas, et al.
(author)
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BNP eller NT-proBNP bör analyseras vid misstänkt hjärtsvikt : Riktlinjer för analys och tolkning
- 2006
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In: Läkartidningen. - 0023-7205 .- 1652-7518. ; 103:17, s. 1289-1292, 1295
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Journal article (peer-reviewed)abstract
- Available data indicate that the use of B-type natriuretic peptide (BNP) or N-terminal-proBNP (NT-proBNP) improve the diagnostics of suspected heart failure as compared to the currently used clinical diagnosis. The increased use of these diagnostic aids is therefore desirable. Since the predictive values are less than 100 procent and the levels are affected by many other factors but heart failure, the results of such measurement should not be used in isolation, but together with a proper clinical judgement. BNP and NT-proBNP are strongly related to the prognosis of most heart diseases, but we are still missing sufficient scientific proof to recommend the measurement of these hormones routinely for monitoring and therapy control.
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| 4. |
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| 5. |
- Venge, Per, et al.
(author)
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Clinical performance of two highly sensitive cardiac troponin I assays
- 2009
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In: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 55:1, s. 109-116
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Journal article (peer-reviewed)abstract
- BACKGROUND: The aim of this study was to compare the clinical performance of 2 sensitive cTnI assays with 10% CV imprecision below the 99th percentile upper reference limit. METHODS: We measured cardiac troponin and N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations in a random sample of the Global Use of Strategies To Open Occluded Coronary Arteries (GUSTO) IV cohort (n = 1251). Outcome data of 1-year mortality and the composite endpoint DMI [death and/or myocardial infarction (MI) within 30 days] were available in all patients. The 99th percentile of a healthy population was estimated from the Sweden Women and Men and Ischemic Heart Disease (SWISCH) cohort (n = 442). We measured cardiac troponin I (cTnI) using the Access AccuTnI (Beckman Coulter) and Centaur TnI Ultra (Siemens Healthcare Diagnostics) and NT-proBNP using the Elecsys 2010 (Roche Diagnostics). RESULTS: Applying the 10% CV cutoff, the sensitivity of the Access AccuTnI assay in identifying DMI and death was higher than that of the Centaur TnI Ultra (P = 0.02 and P < 0.001), and the AccuTnI assay also identified more patients at risk (P < 0.001) and with poor outcome. Applying the 99th percentile cutoffs, AccuTnI identified more patients at risk than the Centaur TnI (P < 0.001) and with significant differences in outcome. Significantly more patients with cardiac troponins below the cutoffs as measured by Centaur TnI had increased NT-proBNP concentrations (P < 0.001) compared with AccuTnI. CONCLUSIONS: The AccuTnI assay identified more patients at risk than the Centaur cTnI Ultra assay. Our results demonstrate the clinical potential of high-sensitivity cardiac troponin assays for the identification of patients at risk of dying from cardiovascular disease.
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| 6. |
- Venge, Per, et al.
(author)
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Normal plasma levels of cardiac troponin I measured by the high-sensitivity cardiac troponin I access prototype assay and the impact on the diagnosis of myocardial ischemia
- 2009
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In: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097 .- 1558-3597. ; 54:13, s. 1165-1172
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Journal article (peer-reviewed)abstract
- OBJECTIVES: This study sought to evaluate the analytical and clinical performance of the novel hypersensitive cardiac troponin I (cTnI) prototype assay from Beckman Coulter (Fullerton, California). BACKGROUND: Studies on patients with acute coronary syndromes and on seemingly healthy subjects have shown that even very minor elevations of cardiac troponins are associated with an increased risk of death. However, the normal plasma levels of cardiac troponins are still not known. METHODS: cTnI plasma levels were measured in 542 healthy subjects, 319 men (age 59.9 +/- 11.8 years) and 213 women (age 59.8 +/- 13.1 years), and in 1,503 randomly selected patients of the GUSTO IV (Global Utilization of Strategies To open Occluded arteries IV) cohort with unstable angina and non-ST-segment elevation myocardial infarctions (MIs). RESULTS: The cTnI levels at 10% coefficient of variation and 20% coefficient of variation imprecision were 0.0033 and 0.0016 microg/l, respectively. The cTnI levels were measurable in >95% of the healthy subjects. The median level of healthy subjects <60 years of age was 0.0032 microg/l (range 0.0011 to 0.0079 microg/l) with the 99th percentile being 0.010 microg/l. No sex differences were observed. A receiver-operator characteristic curve analysis showed an optimal discrimination between healthy subjects and patients at 0.0064 microg/l with a sensitivity of 84.8% (95% confidence interval: 82.8% to 86.6%) and specificity of 89.7% (95% confidence interval: 86.8% to 92.2%). Outcomes as to death and/or MI were significantly different at this level (p < 0.01) in the GUSTO IV cohort. CONCLUSIONS: The novel high-sensitivity cTnI prototype assay from Beckman Coulter allows for the first time the measurement of cTnI levels in almost all healthy subjects. Our data indicate that the assay may be a powerful aid in the diagnosis and outcome prediction of patients with suspected myocardial ischemia and question any definition of myocardial infarction.
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