Search

Background: High-sensitivity cardiac troponin (hs-cTn) assays seem to improve the early diagnosis of acute myocardial infarction (AMI), but it is unknown how to best use them in clinical practice. Our objective was to develop and validate an algorithm for rapid rule-out and rule-in of AMI., Methods: A prospective multicenter study enrolling 872 unselected patients with acute chest pain presenting to the emergency department. High-sensitivity cardiac troponin T (hs-cTnT) was measured in a blinded fashion at presentation and after 1 hour. The final diagnosis was adjudicated by 2 independent cardiologists. An hs-cTnT algorithm incorporating baseline values as well as absolute changes within the first hour was derived from 436 randomly selected patients and validated in the remaining 436 patients. The primary prognostic end point was death during 30 days of follow-up., Results: Acute myocardial infarction was the final diagnosis in 17% of patients. After applying the hs-cTnT algorithm developed in the derivation cohort to the validation cohort, 259 patients (60%) could be classified as "rule-out," 76 patients (17%) as "rule-in," and 101 patients (23%) as in the "observational zone" within 1 hour. Overall, this resulted in a sensitivity and negative predictive value of 100% for rule-out, a specificity and positive predictive value of 97% and 84%, respectively, for rule-in, and a prevalence of AMI of 8% in the observational zone group. Cumulative 30-day survival was 99.8%, 98.6%, and 95.3% (P < .001) in patients classified as rule-out, observational zone, and rule-in, respectively., Conclusions: Using a simple algorithm incorporating hs-cTnT baseline values and absolute changes within the first hour allowed a safe rule-out as well as an accurate rule-in of AMI within 1 hour in 77% of unselected patients with acute chest pain. This novel strategy may obviate the need for prolonged monitoring and serial blood sampling in 3 of 4 patients.

Objective: The early diagnosis of acute myocardial infarction (AMI) can be particularly challenging in patients with known coronary artery disease (CAD) due to pre-existing ECG changes and chronic increases in cardiac troponin (cTn) levels., Design: Of 1170 consecutive patients presenting with symptoms suggestive of AMI, 433 (37%) with pre-existing CAD were analysed in a prospective multicentre study and the diagnostic and prognostic impact of copeptin in combination with either fourth generation cardiac troponin T (cTnT) or high-sensitivity cTnT (hs-cTnT) was evaluated., Results: AMI was the final diagnosis in 78 patients with pre-existing CAD (18%). Copeptin was significantly higher in patients with AMI than in those without (26 pmol/l (IQR 9-71) vs 7 pmol/l (IQR 4-16), p<0.001). The diagnostic accuracy for AMI as quantified by the area under the receiver operating characteristic curve (AUC) was significantly higher for the combination of copeptin and cTnT than for cTnT alone (0.94 vs 0.86, p<0.001). The combination of copeptin and hs-cTnT (0.94) was trending to superiority compared with hs-cTnT alone (0.92, p=0.11). The combination of copeptin and the cTn assays was able to improve the negative predictive value up to 99.5% to rule out AMI. Copeptin was a strong and independent predictor of 1-year mortality (HR 4.18-4.63). Irrespective of cTn levels, patients with low levels of copeptin had an excellent prognosis compared with patients with raised levels of both copeptin and cTn (360-day mortality 2.8-3.6% vs 23.1-33.8%, p<0.001)., Conclusion: In patients with pre-existing CAD, copeptin significantly improves the diagnostic accuracy if used in addition to cTnT, but only trended to superiority compared with hs-cTnT alone. Copeptin provides independent prognostic information, largely by overcoming the challenging interpretation of mild increases in hs-cTnT., Clinical Trial Registration Number: ClinicalTrials Gov number NCT00470587.

Background: Current guidelines for the diagnosis of acute myocardial infarction (AMI), among other criteria, also require a rise and/or fall in cardiac troponin (cTn) levels. It is unknown whether absolute or relative changes in cTn have higher diagnostic accuracy and should therefore be preferred., Methods and Results: In a prospective, observational, multicenter study, we analyzed the diagnostic accuracy of absolute (Δ) and relative (Δ%) changes in cTn in 836 patients presenting to the emergency department with symptoms suggestive of AMI. Blood samples for the determination of high-sensitive cTn T and cTn I ultra were collected at presentation and after 1 and 2 hours in a blinded fashion. The final diagnosis was adjudicated by 2 independent cardiologists. The area under the receiver operating characteristic curve for diagnosing AMI was significantly higher for 2-hour absolute (Δ) versus 2-hour relative (Δ%) cTn changes (area under the receiver operating characteristic curve [95% confidence interval], high-sensitivity cTn T: 0.95 [0.92 to 0.98] versus 0.76 [0.70 to 0.83], P<0.001; cTn I ultra: 0.95 [0.91 to 0.99] versus 0.72 [0.66 to 0.79], P<0.001). The receiver operating characteristic curve-derived cutoff value for 2-hour absolute (Δ) change was 0.007 μg/L for high-sensitivity cTn T and 0.020 μg/L for cTn I ultra (both cutoff levels are half of the 99th percentile of the respective cTn assay). Absolute changes were superior to relative changes in patients with both low and elevated baseline cTn levels., Conclusions: Absolute changes of cTn levels have a significantly higher diagnostic accuracy for AMI than relative changes, and seem therefore to be the preferred criteria to distinguish AMI from other causes of cTn elevations., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. UNIQUE IDENTIFIER: NCT00470587.

Background: The rapid and reliable diagnosis of acute myocardial infarction is a major unmet clinical need., Methods: We conducted a multicenter study to examine the diagnostic accuracy of new, sensitive cardiac troponin assays performed on blood samples obtained in the emergency department from 718 consecutive patients who presented with symptoms suggestive of acute myocardial infarction. Cardiac troponin levels were determined in a blinded fashion with the use of four sensitive assays (Abbott-Architect Troponin I, Roche High-Sensitive Troponin T, Roche Troponin I, and Siemens Troponin I Ultra) and a standard assay (Roche Troponin T). The final diagnosis was adjudicated by two independent cardiologists., Results: Acute myocardial infarction was the adjudicated final diagnosis in 123 patients (17%). The diagnostic accuracy of measurements obtained at presentation, as quantified by the area under the receiver-operating-characteristic curve (AUC), was significantly higher with the four sensitive cardiac troponin assays than with the standard assay (AUC for Abbott-Architect Troponin I, 0.96; 95% confidence interval [CI], 0.94 to 0.98; for Roche High-Sensitive Troponin T, 0.96; 95% CI, 0.94 to 0.98; for Roche Troponin I, 0.95; 95% CI, 0.92 to 0.97; and for Siemens Troponin I Ultra, 0.96; 95% CI, 0.94 to 0.98; vs. AUC for the standard assay, 0.90; 95% CI, 0.86 to 0.94). Among patients who presented within 3 hours after the onset of chest pain, the AUCs were 0.93 (95% CI, 0.88 to 0.99), 0.92 (95% CI, 0.87 to 0.97), 0.92 (95% CI, 0.86 to 0.99), and 0.94 (95% CI, 0.90 to 0.98) for the sensitive assays, respectively, and 0.76 (95% CI, 0.64 to 0.88) for the standard assay. We did not assess the effect of the sensitive troponin assays on clinical management., Conclusions: The diagnostic performance of sensitive cardiac troponin assays is excellent, and these assays can substantially improve the early diagnosis of acute myocardial infarction, particularly in patients with a recent onset of chest pain. (ClinicalTrials.gov number, NCT00470587.), (2009 Massachusetts Medical Society)

Objectives: The purpose of this study was to examine the incremental value of copeptin for rapid rule out of acute myocardial infarction (AMI)., Background: The rapid and reliable exclusion of AMI is a major unmet clinical need. Copeptin, the C-terminal part of the vasopressin prohormone, as a marker of acute endogenous stress may be useful in this setting., Methods: In 487 consecutive patients presenting to the emergency department with symptoms suggestive of AMI, we measured levels of copeptin at presentation, using a novel sandwich immunoluminometric assay in a blinded fashion. The final diagnosis was adjudicated by 2 independent cardiologists using all available data., Results: The adjudicated final diagnosis was AMI in 81 patients (17%). Copeptin levels were significantly higher in AMI patients compared with those in patients having other diagnoses (median 20.8 pmol/l vs. 6.0 pmol/l, p < 0.001). The combination of troponin T and copeptin at initial presentation resulted in an area under the receiver-operating characteristic curve of 0.97 (95% confidence interval: 0.95 to 0.98), which was significantly higher than the 0.86 (95% confidence interval: 0.80 to 0.92) for troponin T alone (p < 0.001). A copeptin level <14 pmol/l in combination with a troponin T < or =0.01 microg/l correctly ruled out AMI with a sensitivity of 98.8% and a negative predictive value of 99.7%., Conclusions: The additional use of copeptin seems to allow a rapid and reliable rule out of AMI already at presentation and may thereby obviate the need for prolonged monitoring and serial blood sampling in the majority of patients. (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE]; NCT00470587).

Abstract: Background: The introduction of high-sensitivity cardiac troponin (hs-cTn) assays allows the assessment of clinical decision values below the 99th percentile. Methods: Final diagnosis and one-year mortality were adjudicated in a multicenter, prospective cohort of 1181 patients presenting with acute chest pain to the emergency department. Hs-cTnT (Roche) and cTnI-ultra (Siemens) were measured in a blinded fashion. Results: At presentation hs-cTnT and cTnI-ultra were below the limit of blank (LOB) in 201 (17%) and 549 (47%) patients, below the 75th percentile in 379 (32%) and 623 (53%) patients, below the 95th percentile in 603 (51%) and 808 (68%), and below the 99th percentile in 748 (63%) and 913 (77%), respectively. Sensitivities for the diagnosis of AMI were 100.0% and 96.8% respectively for hs-cTnT and cTnI-ultra (LOB as cut-off value), 99.5% and 96.2% (75th percentile), 96.8% and 93.0% (95th percentile), and 94.1% and 88.1% (99th percentile). The proportion of patients correctly classified as having or not AMI increased from 32.9% (LOB as cut-off value) to 47.8% (75th percentile), 65.9% (95th percentile) and 77.3% (99th percentile) for hs-cTnT and from 61.2% to 67.3%, 81.9% and 89.3% respectively for cTnI-ultra. At 1year, all-cause mortality was very low and similar for patients below all of these cut-off levels (between 0.7% and 1.5%, p=0.748 for all-groups comparison). Conclusion: cTn should be considered as a continuous variable. Decision values below the 99th percentile (e.g. the 75th percentile) are associated with a very high NPV for the diagnosis of AMI, but have a lower accuracy than the 99th percentile. [Copyright &y& Elsevier]