What to Do about False-Positive Troponin Test Results(Jan06)

FDA has issued a Safety Tip about the possibility of false positive results when troponin testing is used to help diagnose acute myocardial infarction i.e., cases where the troponin immunoassay test is positive in the absence of AMI. False positive troponin tests are rare, but they can have serious consequences, because they can cause clinicians to suspect an acute MI when in fact none has occurred.

The Safety Tip lists the factors that can interfere with accurate analysis, including the presence of clots and certain antibodies in the patient's blood sample, and it gives methods for reducing or removing interfering antibodies from the sample. It notes that lab personnel should suspect the presence of interfering antibodies when the test results don't agree with the patient's clinical presentation or when they're not reproducible.

The Safety Tip also provides both clinicians and lab personnel with steps they should take if the troponin test doesn't match the patient's clinical presentation for AMI. For example, lab personnel should determine whether the patient is on anticoagulant therapy, examine the specimen for particles and clots, and re-run the specimen after doing a serial dilution to see if the results are linear.

Clinicians should consider repeating the troponin test, as well as performing additional diagnostic testing. They should bear in mind that other clinical conditions may cause an elevated troponin level, and that the troponin test is only one tool among many in diagnosing AMI.

Category:

News & Politics

Tags:

• False-Positive
• Troponin
• Test
• Results
• Acute
• Myocardial
• Infarction
• FDA
• Patient
• Safety