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This nice (and brief) review article on interpreting elevated troponin levels can be summed up by its quote from cardiologist Robert Jesse:
“When troponin was a lousy assay it was a great test, but now that it's becoming a great assay, it's getting to be a lousy test.”
Troponin abnormality is set at the 99th percentile in the healthy population. As troponin tests have become more and more sensitive, the absolute cutoff value for "abnormal" troponin has become lower and lower. As you've undoubtedly discovered, "abnormal" troponin includes a lot of unhealthy people in a lot of clinical situations that don't include occlusion of their coronary arteries by ruptured atherosclerotic plaques (severe hypertension, renal disease, myocarditis, severe sepsis, and many more*).
This is a brief article that reviews the physiology and kinetics of troponin release and clearance, and emphasizes the need for serial troponin testing and evaluating the results in proper clinical context. Although in 1,200 words the authors don't really get you out of all (or maybe any) of the dilemmas of interpreting high troponin levels, it's a good update and it's free full text.
Mahajan VS, Jarolim P. Clinician Update: How to Interpret Elevated Cardiac Troponin Levels. Circulation 2011;124:2350-2354.
* Many conditions other than acute coronary syndrome cause elevated troponin levels; here are most of them, divided into primary cardiac and noncardiac causes:
Noncardiac Causes of Increased Troponin Levels
- Renal failure
- Pulmonary embolism
- Severe pulmonary hypertension
- Severe critical illness
- Extreme exertion
- Amyloidosis or other infiltrative diseases
- Stroke and subarachnoid hemorrhage
Cardiac Causes of Elevated Troponin (besides ACS)
- Acute and chronic heart failure
- Cardiac contusion from trauma
- Endomyocardial biopsy
- Aortic dissection
- Hypertrophic cardiomyopathy
- Aortic valve disease (aortic stenosis or regurgitation)
- Cardiotoxic drugs
- Tachyarrhythmia (SVT, V-tach, atrial fibrillation)
- Bradyarrhythmia or heart block
- Cardiac surgery
- Tako-tsubo cardiomyopathy
- Stenting or angioplasty (percutaneous coronary intervention/PCI)