From the Guidelines
Elevated troponin levels without myocardial infarction can occur in several clinical conditions and requires careful evaluation, with management focusing on identifying and treating the underlying cause rather than assuming coronary artery disease, as recommended by the 2016 ESC guidelines for the management of acute coronary syndromes 1. When troponin is elevated but coronary angiography or other cardiac tests don't show evidence of acute myocardial infarction, consider alternative diagnoses such as:
- Myocarditis
- Pulmonary embolism
- Sepsis
- Renal failure
- Heart failure
- Tachyarrhythmias Initial steps include comprehensive cardiac evaluation with:
- ECG
- Echocardiography
- Possibly cardiac MRI to assess for structural abnormalities or inflammation Serial troponin measurements can help determine if levels are rising (suggesting acute injury) or stable (suggesting chronic elevation). Treatment depends on the identified cause, such as:
- Anti-inflammatory therapy for myocarditis
- Anticoagulation for pulmonary embolism
- Rate control for tachyarrhythmias Troponin elevation occurs because these conditions can cause cardiac stress or minor myocardial injury through mechanisms like oxygen supply-demand mismatch, direct cardiac inflammation, or increased wall stress, even without coronary artery occlusion, as noted in the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes 1. In patients with chronic kidney disease, troponin may remain persistently elevated due to decreased clearance rather than ongoing cardiac damage, highlighting the importance of considering the clinical context and assay characteristics when interpreting troponin results, as discussed in the 2014 AHA/ACC guideline 1.
From the Research
Significance of Elevated Troponin Levels
Elevated troponin levels are a sensitive marker of myocardial injury, but they do not necessarily indicate myocardial ischemia or infarction 2, 3, 4. The causes of troponin elevation can be diverse and include conditions such as:
- Cardiomyopathy
- Pulmonary embolism
- Myocarditis
- Renal failure
- Sepsis
- Systemic inflammation
- Physical exertion
- Inflammatory heart diseases (myocarditis and endocarditis) 5
Diagnostic Considerations
The diagnosis of myocardial infarction should not be based solely on elevated troponin levels, as this can lead to unnecessary and expensive invasive testing 2. A comprehensive diagnostic approach should include:
- Electrocardiogram (ECG) findings
- Clinical presentation
- Laboratory results
- Imaging studies (e.g., echocardiogram, coronary angiogram) 3, 6
- Consideration of alternative causes of troponin elevation 4, 5
Prognostic Value
Elevated troponin levels, even in the absence of myocardial infarction, retain prognostic value and should be taken into account when assessing patient risk 4. However, the underlying cause of the troponin elevation should be targeted, rather than relying solely on antithrombotic and antiplatelet agents 4.