Is troponin testing necessary in a patient with resolved tachycardia (rapid heart rate) and chest tightness who is now asymptomatic?

From the Guidelines

Troponin testing is necessary for this patient, even though they are currently asymptomatic and not tachycardic, to rule out myocardial injury. When a patient presents with a history of chest tightness and tachycardia, obtaining a troponin level is crucial to identify potential cardiac damage, as indicated by the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes 1. The guideline recommends serial cardiac troponin I or T levels at presentation and 3 to 6 hours after symptom onset in all patients who present with symptoms consistent with acute coronary syndrome (ACS) to identify a rising and/or falling pattern of values 1. Key points to consider in this scenario include:

• The patient's initial symptoms of chest tightness and tachycardia suggest a possible ACS, which warrants further investigation with troponin testing 1.
• The absence of ongoing symptoms does not exclude the possibility of myocardial damage that occurred during the symptomatic period, making troponin testing an essential component of the evaluation.
• The 2014 AHA/ACC guideline emphasizes the importance of troponin testing in patients with suspected ACS, even if the initial ECG is not diagnostic, to detect ischemic changes and identify patients at high risk of adverse outcomes 1. Therefore, troponin testing should be performed at presentation and repeated at 3-6 hours to ensure accurate diagnosis and appropriate management of potential myocardial injury.

From the Research

Diagnostic Evaluation for Acute Coronary Syndrome

• The patient's initial presentation of chest tightness and tachycardia, followed by asymptomatic status, still warrants further evaluation for acute coronary syndrome (ACS) 2, 3, 4.
• Electrocardiography (ECG) should be performed within 10 minutes of presentation to distinguish between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation ACS (NSTE-ACS) 3, 4.
• If the ECG finding is normal, troponin levels should be measured using one of several recommended protocols to rule out ACS 2, 3, 5.
• High-sensitivity troponin measurements are the preferred test to evaluate for non-ST-segment elevation myocardial infarction (NSTEMI) 4.
• A validated risk score, such as the Thrombolysis in Myocardial Infarction score or HEART score, may also be useful in assessing the patient's risk for ACS 2, 3.

Troponin Measurement and Interpretation

• Cardiac troponin (cTn) is the gold-standard marker for acute myocardial necrosis and is highly specific for myocardial injury 6.
• Elevated cTn levels can occur in acute non-ACS conditions, as well as in chronic diseases, and are directly correlated to prognosis 6.
• The ability to detect increased cTn using high-sensitivity assays following extreme exercise or other non-ACS conditions emphasizes the need to interpret cTn levels in the context of the patient's condition and according to standard recommendations 6, 5.
• Diagnostic algorithms based on up-to-date evidence should be used to enhance the efficient differential diagnosis of acute coronary syndromes in the emergency department 5.

Risk Stratification and Further Evaluation

• If the ECG finding is normal and results of two troponin tests are negative, risk stratification should be calculated using a validated risk score to determine the need for further evaluation 2.
• Further evaluation to exclude coronary artery disease (CAD) may include exercise treadmill testing, stress echocardiography, myocardial perfusion scintigraphy, or coronary computed tomography angiography 2, 3, 4.
• Prompt invasive coronary angiography and percutaneous or surgical revascularization may be necessary for high-risk patients with NSTE-ACS without contraindications 4.