From the Guidelines
Elevated troponin levels without evidence of a heart attack require further evaluation to determine the underlying cause, and management should be directed at the specific condition, rather than the troponin elevation itself, as recommended by the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes 1.
Key Considerations
- Elevated troponin levels can occur due to various non-cardiac and cardiac conditions, including severe infections, sepsis, pulmonary embolism, kidney disease, strenuous exercise, myocarditis, pericarditis, heart failure, and cardiac contusion.
- The degree of elevation, pattern over time, and clinical context are crucial in determining the significance of elevated troponin levels.
- The 99th percentile of the upper reference level is the appropriate cutpoint for considering myocardial necrosis, and serial changes in troponin values are essential for the diagnosis of acute myocardial infarction 1.
Diagnostic Approach
- Measure cardiac-specific troponin (troponin I or T) at presentation and 3–6 hours after symptom onset in all patients with suspected acute coronary syndromes.
- Obtain additional troponin levels beyond 6 hours in patients with initial normal serial troponins and electrocardiographic changes and/or intermediate/high-risk clinical features.
- Consider time of presentation as the time of onset with ambiguous symptom onset for assessing troponin values.
Treatment
- Treatment should be directed at the underlying condition, rather than the troponin elevation itself.
- For example, antibiotics for infection, anticoagulation for pulmonary embolism, or anti-inflammatory medications for myocarditis.
Important Notes
- Troponin elevation occurs when cardiac muscle cells are damaged, releasing this protein into the bloodstream.
- While troponin is a sensitive marker for cardiac injury, its specificity for heart attack is lower, which explains why elevations can occur in various conditions.
- The use of assays that do not have independent validation of optimal precision (CV10%) is not recommended 1.
From the Research
Elevated Troponin Without Evidence of Heart Attack
Elevated troponin levels without evidence of a heart attack can be caused by various factors, including myocardial injury, which is a condition where the heart muscle is damaged but not necessarily due to a heart attack.
- Myocardial injury can be acute or chronic and can be caused by a wide range of mechanisms, including myocarditis, pericarditis, pulmonary embolism, and cardiomyopathy 2, 3, 4.
- The diagnosis of myocardial injury is based on elevated troponin levels, as well as clinical evidence of myocardial damage, such as symptoms, changes in the electrocardiogram (ECG), and wall motion abnormalities 4.
- The management of patients with elevated troponin levels without evidence of a heart attack depends on the underlying cause of the elevation and may involve further evaluation, including laboratory testing, ECG, and echocardiogram, as well as treatment of the underlying condition 2, 3.
Differential Diagnosis
The differential diagnosis of elevated troponin levels without evidence of a heart attack is broad and can include:
- Myocarditis
- Pericarditis
- Pulmonary embolism
- Cardiomyopathy
- Chronic kidney disease
- Sepsis
- Trauma
- Infiltrative diseases, such as amyloidosis or sarcoidosis 2, 3, 4.
Diagnostic Evaluation
The diagnostic evaluation of patients with elevated troponin levels without evidence of a heart attack should include:
- A detailed history and physical examination
- Laboratory testing, including troponin levels, complete blood count, and electrolyte panel
- ECG
- Echocardiogram
- Further testing, such as cardiac magnetic resonance imaging (MRI) or computed tomography (CT) scan, may be necessary to determine the underlying cause of the elevation 2, 3, 4.
Prognosis
The prognosis of patients with elevated troponin levels without evidence of a heart attack depends on the underlying cause of the elevation.