Different time frames for the occurrence of elevated levels of cardiac troponin T and C-reactive protein in patients with acute myocardial infarction

The baseline plasma level of C-reactive protein (CRP) is considered to be a parameter for risk stratification in patients with an acute coronary syndrome, independent of the level of cardiac troponin T (cTnT) or cardiac troponin I. However, myocardial tissue necrosis following prolonged arterial occlusion also induces release of CRP. Both phenomena may have their own kinetic behaviour with respect to changes in concentration of CRP. Therefore, in this study the time frame after onset of symptoms for measurement of CRP as an independent parameter is established. For this purpose, we evaluated patients with proven myocardial damage due to acute myocardial infarction (AMI) with respect to changes of creatine kinase (CK)-MB mass, cTnT and CRP during 24 hours after onset of symptoms. Our results show that two subgroups can be discerned in patients with AMI: those with initially normal and those with already elevated concentration CRP on admission. Furthermore, based on the results of this study we conclude that for use of CRP as an independent prognostic parameter in patients with acute coronary syndrome, CRP should be measured in blood samples drawn as early as possible after the onset of symptoms to avoid contribution of a process of myocardial tissue necrosis, whereas estimation of cTnT should be performed at 6-12 hours