Cardiac myosin-binding protein C (cMyC) was found superior to Troponins for early diagnosis of myocardial infarction with chest pain less than 3 hours at presentation in recent study published in Circulation . cMyC is more abundant than cardiac troponin and is released more rapidly after myocardial infarction. Though high sensitivity troponin estimation is very useful for the diagnosis of acute myocardial infarction, the slow release of this biomarker makes diagnosis difficult in the emergency department for those presenting early after onset of symptoms. Hence European guidelines do not support the use of high sensitivity troponin for early rule / in rule out pathways for those who present early after the onset of chest pain. Guidelines allow the use only after 3 hours of onset of chest pain. The current study involved 1954 patients who presented to the emergency department with symptoms suggestive of acute myocardial infarction, of which 340 were confirmed to have myocardial infarction later. cMyC classified patients with a single blood test into rule-out or rule-in categories accurately. cMyC was found to be better than high sensitivity troponin in early presenters (<3 hours) in achieving this classification. It was also superior to high sensitivity troponin I in predicting death at 3 years, which was similar to high sensitivity Troponin T.
- Kaier TE et al. Direct Comparison of Cardiac Myosin-Binding Protein C With Cardiac Troponins for the Early Diagnosis of Acute Myocardial Infarction. Circulation. 2017;136:1495-1508.