Cardiac biomarkers are enzymes, proteins, and hormones such as CKMB, Troponin, Myoglobin and BNP (Brain Natriuretic Peptide) that are associated with heart function, damage or failure. These biomarker tests are frequently ordered by doctors when someone comes into the Emergency Room complaining of symptoms, such as chest pain, pressure, nausea, and shortness of breath.
These symptoms may indicate a sudden decrease in the amount of blood and oxygen, also termed 'ischemia,' reaching the heart. This decrease can be due to either a narrowing of the coronary arteries (atherosclerosis) or a blood clot (thrombus) which blocks the blood flow to the heart. If the oxygen supply to the heart is low, it can cause pain (angina). If the blood flow is reduced, it can cause death of heart cells (myocardial infarction or heart attack).
The goal with cardiac biomarkers is to be able to detect the presence and severity of an acute heart condition and differentiate from other conditions such as pulmonary embolism, as soon as possible, The patients prognosis is better whenever the appropriate treatment can be quickly started. Cardiac Biomarkers are used: to track the progress of a heart attack, to estimate when it began, and to monitor for recurrence.
Different biomarkers have different times that their levels rise, peak, and fall within the body. For years the gold standard was to watch for an elevation of the CKMB iso-enzyme of CK (creatine kinase) by testing every 8 -10 hours over a period of 24-48 hours. But the search was on to find other markers which would be even more specific for the cardiac muscle and which would elevate & peak within the 1st few hours of symptoms.
Troponin I, Myoglobin, and BNP are now being used more frequently than CKMB. Each of these tests has very specific specimen requirements, depending on the test method used. It is very important that the correct specimen be drawn, kept at the correct temperature, transported to the lab immediately, and tested immediately. It is not uncommon for Emergency departments to expect a turn-around-time of less than 30 minutes for the Cardiac Biomarker tests.