Earliest Cardiac Biomarker Elevation in Acute Myocardial Infarction
The earliest conventional cardiac biomarker to elevate in acute myocardial infarction (MI) is myoglobin. [1] Myoglobin rises more rapidly after MI than CK-MB and can be detected early after onset of infarction. [2]
Myoglobin
Myoglobin is a rapidly released protein from injured cardiac muscle that is detectable earlier than CK-MB and troponin in the acute period. [2] Myoglobin is described as the earliest marker in emergency-department biomarker evaluation studies. [3]
Creatine Kinase–MB (CK-MB)
CK-MB elevation occurs later than myoglobin after MI onset. [2] CK-MB is one of the conventional markers used for assessment of suspected acute MI. [3]
Cardiac Troponin (cTnT or cTnI)
Cardiac troponin elevation occurs later than myoglobin and is used as the primary biomarker for MI diagnosis in contemporary diagnostic frameworks. [1]
Practical Biomarker-Ordering Implication
When early timing clarification is needed after an early presentation, sequential testing may incorporate biomarkers with shorter time courses (such as CK-MB or myoglobin) after an initial troponin result. [1]
Diagnostic Framing for Biomarker “Elevation Order”
MI diagnosis requires detection of a rise and/or fall in cardiac biomarkers with at least one value above the diagnostic threshold in the appropriate clinical setting. [1]