Serial changes in highly sensitive troponin I assay and early diagnosis of myocardial infarction.

CONTEXT: Introduction of highly sensitive troponin assays into clinical practice has substantially improved the evaluation of patients with chest pain. OBJECTIVE: To evaluate the diagnostic performance of a highly sensitive troponin I (hsTnI) assay compared with a contemporary troponin I (cTnI) assay and their serial changes in the diagnosis of acute myocardial infarction (AMI). DESIGN, SETTING, AND PATIENTS: A total of 1818 patients with suspected acute coronary syndrome were consecutively enrolled at the chest pain units of the University Heart Center Hamburg, the University Medical Center Mainz, and the Federal Armed Forces Hospital Koblenz, all in Germany, from 2007 to 2008. Twelve biomarkers including hsTnI (level of detection, 3.4 pg/mL) and cTnI (level of detection, 10 pg/mL) were measured on admission and after 3 and 6 hours. MAIN OUTCOME MEASURES: Diagnostic performance for AMI of baseline and serial changes in hsTnI and cTnI results at 3 hours after admission to the emergency department. RESULTS: Of the 1818 patients, 413 (22.7%) were diagnosed as having AMI. For discrimination of AMI, the area under the receiver operating characteristic (ROC) curve was 0.96 (95% CI, 0.95-0.97) for hsTnI on admission and 0.92 (95% CI, 0.90-0.94) for cTnI on admission. Both were superior to the other evaluated diagnostic biomarkers. The use of hsTnI at admission (with the diagnostic cutoff value at the 99th percentile of 30 pg/mL) had a sensitivity of 82.3% and a negative predictive value (for ruling out AMI) of 94.7%. The use of cTnI (with the diagnostic cutoff value at the 99th percentile of 32 pg/mL) at admission had a sensitivity of 79.4% and a negative predictive value of 94.0%. Using levels obtained at 3 hours after admission, the sensitivity was 98.2% and the negative predictive value was 99.4% for both hsTnI and cTnI assays. Combining the 99th percentile cutoff at admission with the serial change in troponin concentration within 3 hours, the positive predictive value (for ruling in AMI) for hsTnI increased from 75.1% at admission to 95.8% after 3 hours, and for cTnI increased from 80.9% at admission to 96.1% after 3 hours. CONCLUSIONS: Among patients with suspected acute coronary syndrome, hsTnI or cTnI determination 3 hours after admission may facilitate early rule-out of AMI. A serial change in hsTnI or cTnI levels from admission (using the 99th percentile diagnostic cutoff value) to 3 hours after admission may facilitate an early diagnosis of AMI.

Angiographic score assessment improves cardiovascular risk prediction: the clinical value of SYNTAX and Gensini application.

BACKGROUND: Severity of coronary artery disease (CAD) is related to cardiovascular outcome. We aimed to assess the long-term follow-up depending on Synergy between percutaneous coronary intervention with Taxus and cardiac surgery (SYNTAX) and Gensini score for prognosis. Both scores increase with complexity and thus reflect risk of cardiovascular events. METHODS AND RESULTS: We determined complexity and extent of CAD by the SYNTAX and Gensini score in the AtheroGene cohort (N = 1,974, with 22.6 % women). The endpoint was non-fatal myocardial infarction (N = 132) and cardiovascular death (N = 159) over a median follow-up of 5.4 (Q1: 5.23/Q3: 5.57) years up to 8 years maximum (follow-up rate 99.4%). For SYNTAX score, the following distribution was used: low (≤22, N = 1,404), medium (23-32, N = 314), high score (>32, N = 256). Gensini score was split into thirds. Cox regression analysis showed a hazard ratio (HR) of 1.5 (95% confidence interval 1.16-1.95; p = 0.0024) for the log transformed SYNTAX score in a fully adjusted model and a HR of 1.41 (95% CI 1.13-1.77; p = 0.0025) for the Gensini score. The SYNTAX score alone had a C-index of 0.62, whereas adding clinical variables increased the C-index to 0.67. Similar results were obtained for the Gensini score. Regarding the SYNTAX score using net reclassification index, discrimination of events and non-events was enhanced by 37.2% in a model of clinical variables and biomarkers and by 31.8% for the Gensini score. CONCLUSION: The SYNTAX and Gensini score in combination with clinical variables could be used to predict the cardiovascular prognosis during a long-term follow-up of up to 8 years in CAD patients.

Prognostic information of glycogen phosphorylase isoenzyme BB in patients with suspected acute coronary syndrome.

Early and adequate risk stratification is essential in patients with suspected acute coronary syndrome (ACS). The aim of the present study was to investigate whether glycogen phosphorylase BB (GPBB) could add prognostic information in the context of contemporary sensitive troponin I determination and B-type natriuretic peptide (BNP). Patients with suspected ACS were consecutively enrolled at 3 German study centers from January 2007 through December 2008. Troponin I, GPBB, and BNP were determined at admission. Follow-up information on the combined end point of death, myocardial infarction, revascularization, and hospitalization owing to a cardiovascular cause was obtained 6 months after enrollment. In total 1,818 patients (66% men) were enrolled of whom 413 (23%) were diagnosed as having acute myocardial infarction and 240 (13%) as having unstable angina pectoris, whereas in 1,165 patients (64%) an ACS could be excluded. Follow-up information was available in 98% of patients; 203 events were registered. GPBB measured on admission predicted an unfavorable outcome with a hazard ratio of 1.24 (p <0.05) in an unadjusted Cox regression model and showed a tendency with a hazard ratio of 1.13 (p = 0.07) in a fully adjusted model. Kaplan-Meier analysis revealed a poorer outcome in patients with increased GPBB levels amendatory to the information provided by troponin I or BNP. In conclusion, GPBB measurement provides predictive information on midterm prognosis in patients with chest pain in addition to BNP and troponin I.

Copeptin improves early diagnosis of acute myocardial infarction.

OBJECTIVES: Early identification of myocardial infarction in chest pain patients is crucial to identify patients at risk and to maintain a fast treatment initiation. BACKGROUND: The aim of the current investigation is to test whether determination of copeptin, an indirect marker for arginin-vasopressin, adds diagnostic information to cardiac troponin in early evaluation of patients with suspected myocardial infarction. METHODS: Between January 2007 and July 2008, patients with suspected acute coronary syndrome were consecutively enrolled in this multicenter study. Copeptin, troponin T (TnT), myoglobin, and creatine kinase-myocardial band were determined at admission and after 3 and 6 h. RESULTS: Of 1,386 (66.4% male) enrolled patients, 299 (21.6%) had the discharge diagnosis of acute myocardial infarction, 184 (13.3%) presented with unstable angina, and in 903 (65.2%) an acute coronary syndrome could be excluded. Combined measurement of copeptin and TnT on admission improved the c-statistic from 0.84 for TnT alone to 0.93 in the overall population and from 0.77 to 0.9 in patients presenting within 3 h after chest pain onset (CPO) (p < 0.001). In this group the combination of copeptin with a conventional TnT provided a negative predictive value of 92.4%. CONCLUSIONS: In triage of chest pain patients, determination of copeptin in addition to troponin improves diagnostic performance, especially early after CPO. Combined determination of troponin and copeptin provides a remarkable negative predictive value virtually independent of CPO time and therefore aids in early and safe rule-out of myocardial infarction.