From the Guidelines
Elevated troponin levels with normal kidney function typically indicate cardiac injury, most commonly due to acute coronary syndrome (heart attack), and require immediate medical attention. The standard approach to managing such patients includes aspirin, antiplatelet therapy, anticoagulation, and other medications based on the specific diagnosis, as recommended by the 2015 ESC guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation 1.
Key Considerations
- Troponin is a protein released when heart muscle cells are damaged, and its elevation is highly specific for cardiac injury.
- The pattern and timing of troponin elevation, along with clinical symptoms and ECG findings, help determine the underlying cause and appropriate treatment strategy.
- Other conditions like myocarditis, pulmonary embolism, heart failure, cardiac contusion, and certain cardiac procedures can also elevate troponins.
- Normal kidney function is important to note because renal impairment can cause troponin elevation without acute cardiac injury.
Diagnostic Approach
- Measurement of a biomarker of cardiomyocyte injury, preferably high-sensitivity cardiac troponin, is mandatory in all patients with suspected acute coronary syndrome, as stated in the 2015 ESC guidelines 1.
- A dynamic elevation of cardiac troponin above the 99th percentile of healthy individuals indicates myocardial infarction.
- High-sensitivity assays are recommended over less sensitive ones, as they increase diagnostic accuracy for myocardial infarction at the time of presentation, especially in patients presenting early after chest pain onset 1.
Treatment Strategy
- Seek emergency care right away for proper evaluation and treatment if elevated troponins with normal kidney function are encountered.
- The treatment strategy should be based on the specific diagnosis, and may include aspirin, antiplatelet therapy, anticoagulation, and other medications, as recommended by the 2015 ESC guidelines 1.
From the Research
Elevated Troponins with Normal Kidney Function
- Elevated troponin levels are often associated with acute myocardial infarction (AMI), but can also be elevated in patients with chronic kidney disease (CKD) due to various factors such as uremic skeletal myopathy, microinfarctions, left ventricular hypertrophy (LVH), decreased clearance, and unrecognized congestive heart failure (CHF) 2.
- In patients with normal kidney function, elevated troponin levels can indicate AMI, and the diagnosis can be made using electrocardiography changes and troponin levels 3.
- However, the provided studies do not directly address the issue of elevated troponins with normal kidney function, as they primarily focus on patients with CKD or end-stage renal disease (ESRD) 4, 5, 2, 6.
- The use and interpretation of high-sensitivity cardiac troponin assays in patients with normal kidney function are not explicitly discussed in the provided studies, but it is mentioned that these assays can be used to diagnose AMI in patients with normal renal function 4, 6.
- The prognostic significance of elevated troponin levels in patients with normal kidney function is not addressed in the provided studies, but it is noted that elevated troponin levels are associated with adverse outcomes in patients with CKD 4, 6.
Diagnostic Challenges
- Diagnosing AMI in patients with CKD can be challenging due to elevated troponin levels at baseline, which can lead to decreased specificity of troponin tests 4, 5.
- The use of high-sensitivity cardiac troponin assays can help improve the diagnosis of AMI in patients with CKD, but the interpretation of results requires a nuanced approach 2, 6.
- A diagnostic algorithm can be used to risk-stratify patients with CKD who have troponin elevation and suspected AMI 5.
Management Considerations
- Patients with suspected AMI should receive coronary angiography with percutaneous or surgical revascularization, as well as initiation of dual antiplatelet therapy and parenteral anticoagulation, statin therapy, beta-blocker therapy, and sodium-glucose cotransporter-2 inhibitor therapy 3.
- Additional interventions such as smoking cessation, annual influenza vaccination, and cardiac rehabilitation can help reduce mortality in patients who have had a recent myocardial infarction 3.