From the Guidelines
Elevated troponin levels indicate heart muscle damage and require prompt medical evaluation, with the most recent guidelines suggesting that a dynamic elevation of cardiac troponin above the 99th percentile of healthy individuals indicates myocardial infarction (MI) 1.
Interpretation of Elevated Troponin
When interpreting elevated troponin levels, it is essential to consider both cardiac and non-cardiac causes. Cardiac causes include:
- Acute coronary syndrome (heart attack)
- Myocarditis
- Heart failure
- Cardiac procedures Non-cardiac causes include:
- Severe infections
- Pulmonary embolism
- Kidney disease
- Strenuous exercise
- Certain medications The clinical context is crucial, as rapid rises suggest acute injury, while chronic elevations may indicate ongoing conditions.
Diagnostic Approach
The detection of an elevated troponin above the 99th percentile upper reference limit is highly sensitive and specific for myocardial necrosis, and is required in the universal definition of myocardial infarction (MI) 1. Contemporary troponin assays are termed “high-sensitivity” (hs) if they are able to detect measurable troponin levels even in healthy individuals.
Management
Management depends on the underlying cause, ranging from immediate coronary intervention for heart attacks to supportive care for non-cardiac causes. Serial measurements are often more informative than single readings, as the pattern and magnitude of elevation help determine the cause and severity of injury. Any elevated troponin warrants medical attention to determine the appropriate treatment approach, with the goal of minimizing morbidity, mortality, and improving quality of life.
From the Research
Interpreting Elevated Troponin
Elevated troponin levels can be an indicator of various conditions, not just acute coronary syndrome (ACS) or occlusion myocardial infarction (OMI) 2, 3. When interpreting elevated troponin, it is essential to consider the clinical context, patient symptoms, electrocardiogram, and ultrasound results.
Causes of Troponin Elevation
Troponin elevation can be caused by:
- Cardiac conditions such as heart failure, dysrhythmia, and dissection 2
- Non-cardiac conditions like pulmonary embolism, sepsis, stroke, and others 2, 3
- Myocyte injury and necrosis, myocyte apoptosis and cell turnover, and oxygen supply demand mismatch 2
Clinical Predictors and Survival Analysis
Studies have identified predictors for the diagnosis of ACS in patients with elevated troponin levels, including:
- Age between 40 and 70 years
- History of hypertension or ischemic heart disease
- Normal renal function
- Troponin T level higher than 1.0 ng/mL 4 The positive predictive value (PPV) of troponin T for ACS diagnosis was found to be only 56% (95% CI, 52%-60%) 4.
Prognostic Value of Troponin Elevation
Elevated troponin levels in critically ill patients without ACS have been associated with higher mortality and increased incidence of intubation 5. In patients with ACS, elevated troponin levels are a marker for poor outcomes, including increased rates of mortality 2.
Management of Acute Coronary Syndrome
The management of ACS involves various medical therapies, including:
- Aspirin and dual antiplatelet therapy
- Parenteral anticoagulation
- Proton pump inhibitors
- Statins, angiotensin-converting enzyme inhibitors, beta blockers, nitroglycerin, and morphine
- Oxygen therapy and percutaneous coronary intervention (PCI) with stent placement for ST-segment elevation myocardial infarction 6