Risk stratification of chest pain patients by point-of-care cardiac troponin T and myoglobin measured in the emergency department.

A prospective multicenter study including 1410 chest pain patients with suspected acute coronary syndromes was carried out to examine the predictive value of biological cardiac markers for adverse events measured by a point-of-care system. Admission cardiac troponin T (cTnT) and myoglobin were measured in parallel on a point-of-care system in the emergency department and -- together with CK-MB mass -- on lab analyzers. In a one-year follow-up, cardiac and non-cardiac death, acute myocardial infarction, unstable angina pectoris and need for revascularization were registered. Median time between onset of symptoms and admission was 285 min; 172 patients (12.2%) had no event during follow-up. If the cTnT, measured either by the point-of-care system or a conventional lab analyzer, was >0.05 microg/L, then the chance of a cardiac event during the follow-up period was doubled (18% vs. 9%). Serial cTnT measurement did not add any further value to the predictive power of the admission cTnT. Myoglobin and CK-MB mass identified increasing risk with increasing concentration quartiles; cardiac event rates were 2.8- to 4.4-fold higher between the quartiles with the lowest and those with the highest analyte concentration, respectively. There was no difference in non-cardiac death rates between any concentration quartiles. In conclusion, the prediction of clinical events by cardiac troponin T and myoglobin measured with a point-of-care analyzer in the emergency department was as good as that of the same cardiac markers and CK-MB mass measured on lab analyzers.

Natriuretic peptide testing in emergency settings.

Acutely dyspneic patients are challenging, because their symptoms can be due to cardiac, pulmonary or other diseases. B-type natriuretic peptide testing offers higher diagnostic accuracy (85%-90%) than clinical assessments for identifying heart failure as the cause of dyspnea. On the other hand, the high clinical sensitivity and negative predictive value of natriuretic peptides permit to rule out heart failure with an accuracy > 90%. Natriuretic peptides are the most powerful, single prognostic markers of complications associated with acute dyspnea and permit the early recognition of high-risk patients. It has been shown that systematic natriuretic peptide testing reduces the economic expenses associated with clinical management of acutely dyspneic patients. Finally, whether these biomarkers could be used to guide heart failure therapy in the acute setting remains to be elucidated.