To help rule out myocardial ischemia in a person with chest pain
IMA
IMA
Nome formal
Ischemia-Modified Albumin
Este artigo foi revisto pela última vez em
Este artigo foi modificado pela última vez em
21 de Março de 2018.
At a Glance
Why Get Tested?
When To Get Tested?
When you have had chest pain for a few minutes to a few hours and your doctor wants to better determine if you have had or are having a heart attack
Sample Required?
A blood sample drawn from a vein in your arm
Test Preparation Needed?
None
Accordion Title
Common Questions
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How is it used?Ischemia-modified albumin (IMA) is a fairly new test that has been FDA approved to help rule out cardiac ischemia in people with chest pain whose diagnosis is not clear. It is a cardiac biomarker that is meant to be ordered along with or following a troponin test and an ECG.
If the troponin test, which may take several hours to start to increase after an MI, is negative and the ECG is not definitive, then the ischemia-modified albumin test may add valuable information about whether cardiac ischemia is occurring. IMA may be ordered along with a myoglobin test in the first few hours of chest pain to try to stratify the person's risk of having a heart attack in the near future.
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When is it ordered?IMA may be ordered along with or following a troponin, ECG, and sometimes a myoglobin test when someone has chest pains that began within the last few hours and the doctor wants more information about whether the symptoms may be ischemia-related.
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What does the test result mean?Ischemia-modified albumin is a marker of decreased oxygen availability. Studies have shown IMA to be sensitive for ischemia but not very specific, which means that it can be elevated with ischemia in other areas of the body. Its primary value is in its negative predictive value.
When IMA is not present in a person who has been having chest pain for a few minutes to a few hours, then it is unlikely that ischemia has occurred. When IMA and myoglobin are negative, an ECG is normal, and a troponin is negative at initial and repeat testing, then it is unlikely that the person's chest pain has or will result in a heart attack in the near future.
If someone has been experiencing chest pains for several hours, then the IMA test may not be as valuable because it may have already risen and fallen back to normal or near normal levels by the time the blood sample is collected.
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Is there anything else I should know?Research and current studies are evaluating whether a significantly elevated IMA may be useful as a positive indicator that myocardial ischemia is occurring. Increases in IMA have also been seen with ischemia that is occurring in other parts of the body, such as the skeletal muscles and gastrointestinal tract.
The IMA test is not widely used at present. Although it is regarded as a promising cardiac biomarker, its ultimate clinical utility has yet to be determined. Many physicians are adopting a wait-and-see attitude. They want to see more data accumulated on its use and on the factors, such as underlying diseases and decreased albumin levels, that may affect or interfere with its interpretation.
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Can an IMA test be done in a doctor's office?No, the test must be run with specialized equipment. In most cases, the IMA test is ordered when a person is being evaluated for chest pain in the Emergency Room.
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If a person has not had a heart attack, why are they still considered at risk?Often, the situation that is causing the chest pain, such as a partial blockage of an artery, can worsen, becoming fully blocked and causing a heart attack. A person with stable angina can have his condition escalate and become unstable, such as when a narrowed artery finally closes.