The finding of an elevated troponin does not equal that the patient is suffering from an acute myocardial infarction (MI). Although this concept is pivotal in the new MI definition, cardiologists are frequently asked to admit acutely ill patients to the CCU solely based on the finding of an elevated level of cardiac troponin.
Besides being the standard for the biochemical diagnosis of MI, troponin measurement is helpful in MI patients also for risk stratification, assessment of reperfusion and infarct size measurement, as pointed out by Dr. Giannitsis in his presentation.
The finding of increased troponin concentrations after an otherwise successful PCI opens the question whether the patient has to be labelled as affected by post-procedural MI. This complex issue has been discussed by Dr. Ravkilde. The Global MI Task Force is preparing recommendations to help cardiologists to make a correct diagnosis in this context.
Dr. Mair in his presentation has discussed the interpretation of troponin elevations which are frequently found in patients with acute heart failure. There may be difficult cases where the exclusion of an ischemic trigger should be based on the documentation of the presence of coronary artery disease by coronary angiography.
The sensitivity of troponin for the detection of myocardial damage has allowed the appreciation of several conditions in which myocardial damage can occur. All these conditions are in need of differentiation from MI regardless whether this finding is associated or not with worse patient prognosis. Dr. Jaffe has extensively covered this topic presenting original data, obtained in critically ill patients, showing that troponin measurement has incremental value over the Apache II score to detect unfavourable outcome.
Finally Dr. Lindahl has presented data from the GUSTO IV study showing that, in addition to troponin, only the presence of ST-segments shifts on the ECG and renal function measurement have incremental value to improve early risk stratification of patients with acute coronary syndromes.