From the Guidelines
Elevated troponin levels without myocardial infarction can occur due to various non-acute coronary syndrome causes, including chronic or acute renal dysfunction, severe congestive heart failure, hypertensive crisis, tachy- or bradyarrhythmias, pulmonary embolism, and inflammatory diseases such as myocarditis. When evaluating a patient with elevated troponin levels, it is essential to consider these alternative causes and to rule out acute myocardial infarction through coronary angiography or other tests. The management of elevated troponin levels depends on identifying the underlying cause, rather than treating the troponin elevation itself 1.
Key Considerations
- Initial evaluation should include a comprehensive history, physical examination, ECG, echocardiogram, and possibly cardiac MRI if myocarditis is suspected.
- For specific conditions, targeted therapy is required - for example, anticoagulation for pulmonary embolism, antibiotics for sepsis, or anti-inflammatory medications for myocarditis or pericarditis.
- Serial troponin measurements can help monitor the clinical course.
- In patients with chronic kidney disease, persistently elevated troponin may represent baseline values rather than acute cardiac injury.
Non-ACS Causes of Troponin Elevation
- Chronic or acute renal dysfunction
- Severe congestive heart failure – acute and chronic
- Hypertensive crisis
- Tachy- or bradyarrhythmias
- Pulmonary embolism, severe pulmonary hypertension
- Inflammatory diseases, e.g. myocarditis
- Acute neurological disease, including stroke, or subarachnoid haemorrhage
- Aortic dissection, aortic valve disease or hypertrophic cardiomyopathy
- Cardiac contusion, ablation, pacing, cardioversion, or endomyocardial biopsy
- Hypothyroidism
- Apical ballooning syndrome (Tako-Tsubo cardiomyopathy)
- Infiltrative diseases, e.g. amyloidosis, haemochromatosis, sarcoidosis, sclerodermia
- Drug toxicity, e.g. adriamycin, 5-fluorouracil, herceptin, snake venoms
- Burns, if affecting >30% of body surface area
- Rhabdomyolysis
- Critically ill patients, especially with respiratory failure, or sepsis
As noted in the European Society of Cardiology guidelines 1, troponin elevation is frequently found when the serum creatinine level is >2.5 mg/dL (221 mmol/L) in the absence of proven ACS, and is also associated with an adverse prognosis. The universal definition of myocardial infarction also highlights the importance of considering non-ACS causes of troponin elevation 1.
From the Research
Causes of Elevated Troponin Levels
Elevated troponin levels can be caused by a variety of mechanisms in the absence of myocardial ischemia and injury, including:
- Myocardial injury without overt ischemia, which represents about 60% of cases of abnormal troponin concentrations when obtained for clinical indications 2
- Non-AMI conditions such as sepsis, hypovolemia, atrial fibrillation, congestive heart failure, pulmonary embolism, myocarditis, myocardial contusion, and renal failure 3
- Myocyte necrosis and reperfusion 4
- Chronic precipitants such as structural or valvular heart disease 2
Differential Diagnosis
The differential diagnosis of elevated troponin levels is broad and can be divided into acute and chronic precipitants, including:
- Acute myocardial infarction
- Myocardial injury without overt ischemia
- Non-AMI conditions such as sepsis, hypovolemia, atrial fibrillation, congestive heart failure, pulmonary embolism, myocarditis, myocardial contusion, and renal failure
- Chronic precipitants such as structural or valvular heart disease
Diagnostic Evaluation
The initial workup for elevated troponin levels involves an assessment for myocardial ischemia, and if infarction is ruled out, further evaluation includes:
- A detailed history and physical examination
- Laboratory testing
- A 12-lead electrocardiogram
- An echocardiogram (if there is no known history of structural or valvular heart disease) 2
Prognostic Value
Elevated troponin levels, even in the absence of thrombotic acute coronary syndromes, retain prognostic value and are associated with an increased risk of mortality 5, 3