Clinical Management of Elevated Troponin Levels
The initial management of patients with elevated troponin levels should include an early invasive strategy (diagnostic angiography with intent to perform revascularization) for high-risk patients, particularly those with refractory angina or hemodynamic/electrical instability. 1
Initial Assessment and Risk Stratification
- Serial cardiac troponin measurements should be obtained at presentation and 3-6 hours after symptom onset to identify a rising and/or falling pattern consistent with acute myocardial injury 1
- Additional troponin measurements beyond 6 hours should be obtained in patients with normal initial levels when clinical presentation or ECG changes suggest intermediate or high suspicion for acute coronary syndrome 1
- The initial ECG presentation has prognostic value - patients with ST-segment depression have worse prognosis than those with negative T waves or normal ECGs 1
- Risk stratification should be performed using validated risk scores to determine appropriate management strategy and timing of intervention 1
Diagnostic Approach
- Troponin elevations indicate myocardial cell injury but do not define the cause of injury - consider both cardiac and non-cardiac causes 2
- Cardiac causes include acute coronary syndromes, heart failure, dysrhythmias, and aortic dissection 2
- Non-cardiac causes include pulmonary embolism, sepsis, stroke, renal failure, and critical illness 2, 3
- The pattern of troponin elevation is important - a rise and fall pattern is more consistent with acute myocardial infarction than persistently elevated levels 1
- Point-of-care troponin testing may provide initial diagnostic information but has substantially lower sensitivity than central laboratory methods 1
Management Strategy Based on Risk Assessment
High-Risk Patients (Immediate Intervention)
- An early invasive strategy is indicated for patients with:
Intermediate-Risk Patients
- An early invasive strategy (within 24 hours) is reasonable for initially stabilized high-risk patients 1
- For patients not at high risk, a delayed invasive approach is reasonable 1
- Serial ECGs and troponin measurements should be performed to monitor for changes indicating disease progression 1
Low-Risk Patients
- Patients without recurrence of chest pain, with normal or non-specific ECG changes, and normal serial troponin measurements may be considered low risk 1
- For these patients:
- Oral treatment including aspirin, clopidogrel, beta-blockers, and possibly nitrates or calcium antagonists should be initiated 1
- A stress test (exercise ECG, stress myocardial perfusion imaging, or stress echocardiography) should be performed before discharge or within 72 hours 1
- Low-molecular-weight heparin may be discontinued when no ECG changes are apparent and repeat troponin measurement is negative 1
Special Considerations
- Troponin elevations can occur in conditions other than acute coronary syndromes and still indicate poor prognosis 1, 5
- The 5-year mortality rate for patients with myocardial injury without overt ischemia is approximately 70% 5
- Chronic troponin elevations are common in patients with structural heart disease, left ventricular hypertrophy, or renal insufficiency 1, 6
- In patients with end-stage renal disease, troponin elevations are common even without clinical evidence of acute coronary syndrome 1
- For suspected reinfarction during the acute infarct period, an increase of >20% from previous troponin levels may indicate reinfarction 1
Contraindications to Invasive Strategy
- An early invasive strategy is not recommended for patients with:
Registry Participation
- Participation in a national or regional acute myocardial infarction registry that provides regular performance reports based on benchmarked data is recommended for quality improvement 1