Very Early Diagnosis of Chest Pain By Point-of-Care Testing
Objective To assess the impact of triple marker testing on patient management and the diagnostic efficiencies of different biomarker strategies examined.
Design A prospective randomised trial of triple marker testing by point-of-care testing (POCT); the Randomised Assessment of Panel Assay of Cardiac markers (RATPAC) study.
Setting Six emergency departments.
Patients Low-risk patients presenting with chest pain to diagnostic assessment with a cardiac panel measured by POCT or to diagnosis when biomarker measurement was based on central laboratory testing.
Interventions 1125 patients were randomly assigned to POCT measurement of the triple marker panel of cardiac troponin I (cTnI), myoglobin and the MB isoenzyme of creatine kinase (CK-MB) on admission and 90 min from admission.
Main Outcome Measures Myocardial infarction (MI) was defined by the universal definition of MI. The following diagnostic strategies were compared by receiver operator characteristic (ROC) curve analysis and comparison of area under the curve (AUC): individual marker values, change (Δ) in CK-MB and myoglobin and the combination of presentation or 90 min value plus Δ value.
Results Admission sample measurement of cTnI was the most diagnostically efficient AUC 0.96 (0.93–0.98) with areas under the ROC curve statistically significantly greater than CK-MB 0.85 (0.80–0.90) and myoglobin 0.75 (0.68–0.81). At 90 min cTnI measurement had the highest AUC 0.95 (0.87–1.00) but was statistically significantly different only from Δmyoglobin and ΔCK-MB.
Conclusion Measurement of cTnI alone is sufficient for diagnosis. Measurement of a marker panel does not facilitate diagnosis.
Multimarker measurement has been advocated for the early diagnosis of myocardial infarction (MI). This strategy is based on the concept that there is a period of 'troponin blindness' in the early phase of myocyte necrosis when troponin elevation may not be detectable. At presentation or up to 3 h from the onset of chest pain, measurement of cytoplasmic markers such as myoglobin or the MB isoenzyme of creatine kinase (CK-MB) may be more appropriate. This has been particularly advocated for point-of-care testing (POCT), and a protocol based on triple marker testing has been suggested and validated. This has recently been examined prospectively in a multicentre study. The introduction of highly sensitive troponin measurements, capable of measuring troponin values in the reference interval and capable of detecting early increases in troponin challenges this concept.
A prospective randomised multicentre trial of triple marker testing by POCT; the Randomised Assessment of Panel Assay of Cardiac markers (RATPAC) study was performed to assess the impact of POCT triple marker testing on patient management. The RATPAC study is the first prospective multicentre study that has examined POCT triple marker measurements in routine clinical use. The study showed that POCT testing resulted in significantly earlier discharge with no increase in major adverse coronary events (death, readmission with MI or unstable angina or the need for revascularisation) within 3 months compared with patients managed conventionally.
In order to determine if, in POCT, a full triple test panel or troponin alone is sufficient for diagnosis, a substudy of the point-of-care arm was performed. The substudy examined the diagnostic efficiency of the individual component cardiac markers within the panel. The objective was to compare the accuracy of the individual markers and different marker-based strategies in the point-of-care arm of the trial for the final diagnosis of acute myocardial infarction (AMI).
Abstract and Introduction
Abstract
Objective To assess the impact of triple marker testing on patient management and the diagnostic efficiencies of different biomarker strategies examined.
Design A prospective randomised trial of triple marker testing by point-of-care testing (POCT); the Randomised Assessment of Panel Assay of Cardiac markers (RATPAC) study.
Setting Six emergency departments.
Patients Low-risk patients presenting with chest pain to diagnostic assessment with a cardiac panel measured by POCT or to diagnosis when biomarker measurement was based on central laboratory testing.
Interventions 1125 patients were randomly assigned to POCT measurement of the triple marker panel of cardiac troponin I (cTnI), myoglobin and the MB isoenzyme of creatine kinase (CK-MB) on admission and 90 min from admission.
Main Outcome Measures Myocardial infarction (MI) was defined by the universal definition of MI. The following diagnostic strategies were compared by receiver operator characteristic (ROC) curve analysis and comparison of area under the curve (AUC): individual marker values, change (Δ) in CK-MB and myoglobin and the combination of presentation or 90 min value plus Δ value.
Results Admission sample measurement of cTnI was the most diagnostically efficient AUC 0.96 (0.93–0.98) with areas under the ROC curve statistically significantly greater than CK-MB 0.85 (0.80–0.90) and myoglobin 0.75 (0.68–0.81). At 90 min cTnI measurement had the highest AUC 0.95 (0.87–1.00) but was statistically significantly different only from Δmyoglobin and ΔCK-MB.
Conclusion Measurement of cTnI alone is sufficient for diagnosis. Measurement of a marker panel does not facilitate diagnosis.
Introduction
Multimarker measurement has been advocated for the early diagnosis of myocardial infarction (MI). This strategy is based on the concept that there is a period of 'troponin blindness' in the early phase of myocyte necrosis when troponin elevation may not be detectable. At presentation or up to 3 h from the onset of chest pain, measurement of cytoplasmic markers such as myoglobin or the MB isoenzyme of creatine kinase (CK-MB) may be more appropriate. This has been particularly advocated for point-of-care testing (POCT), and a protocol based on triple marker testing has been suggested and validated. This has recently been examined prospectively in a multicentre study. The introduction of highly sensitive troponin measurements, capable of measuring troponin values in the reference interval and capable of detecting early increases in troponin challenges this concept.
A prospective randomised multicentre trial of triple marker testing by POCT; the Randomised Assessment of Panel Assay of Cardiac markers (RATPAC) study was performed to assess the impact of POCT triple marker testing on patient management. The RATPAC study is the first prospective multicentre study that has examined POCT triple marker measurements in routine clinical use. The study showed that POCT testing resulted in significantly earlier discharge with no increase in major adverse coronary events (death, readmission with MI or unstable angina or the need for revascularisation) within 3 months compared with patients managed conventionally.
In order to determine if, in POCT, a full triple test panel or troponin alone is sufficient for diagnosis, a substudy of the point-of-care arm was performed. The substudy examined the diagnostic efficiency of the individual component cardiac markers within the panel. The objective was to compare the accuracy of the individual markers and different marker-based strategies in the point-of-care arm of the trial for the final diagnosis of acute myocardial infarction (AMI).
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