What is the management approach for a patient with a significant troponin (cardiac biomarker) increase or decrease after 1 or 2 hours?

From the Guidelines

For a patient with a significant troponin increase or decrease after 1-2 hours, immediate evaluation for acute coronary syndrome is warranted, with a focus on serial troponin measurements every 3-6 hours, as recommended by the 2017 AHA/ACC guideline 1. The management approach should prioritize the identification of a rising and/or falling pattern of troponin values, as stated in the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes 1. Key considerations include:

• Serial cardiac troponin I or T levels should be obtained at presentation and 3 to 6 hours after symptom onset in all patients who present with symptoms consistent with ACS to identify a rising and/or falling pattern of values 1.
• Additional troponin levels should be obtained beyond 6 hours after symptom onset in patients with normal troponin levels on serial examination when changes on ECG and/or clinical presentation confer an intermediate or high index of suspicion for ACS 1.
• High-sensitivity cardiac troponin I (hs-cTnI) measurements that are less than the 99th percentile, measured at 0 and 2 hours, may be used together with low-risk stratification to predict a less-than-1% chance of 30-day major adverse cardiac events (MACE) 1.
• The use of troponins at 0 and 2 hours as a stand-alone measure for excluding the diagnosis of ACS is strongly discouraged, and instead, should be used in conjunction with clinical risk stratification 1. If the troponin elevation is substantial (typically >99th percentile of normal) with appropriate clinical symptoms, the patient should be treated for acute myocardial infarction with dual antiplatelet therapy, anticoagulation, high-intensity statin therapy, and consideration of beta-blockers and ACE inhibitors if no contraindications exist, as suggested by the 2015 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations 1. The patient should undergo urgent cardiac catheterization, ideally within 90 minutes for STEMI or within 24 hours for NSTEMI, as recommended by the 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care 1. If troponin changes are more modest but still concerning, the patient should be admitted for observation with serial troponin measurements every 3-6 hours, ECG monitoring, and risk stratification, taking into account the recent guidelines and consensus statements 1.

From the Research

Management Approach for Significant Troponin Increase or Decrease

• The management approach for a patient with a significant troponin increase or decrease after 1 or 2 hours involves immediate electrocardiography and high-sensitivity troponin measurements to evaluate for non-ST-elevation myocardial infarction (NSTEMI) 2.
• For patients with ST-segment elevation myocardial infarction (STEMI), rapid reperfusion with primary percutaneous coronary intervention (PCI) within 120 minutes reduces mortality 2.
• In high-risk patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) and no contraindications, prompt invasive coronary angiography and percutaneous or surgical revascularization within 24 to 48 hours are associated with a reduction in death 2.
• Alternative causes for elevated cardiac troponin levels, such as sepsis, hypovolemia, atrial fibrillation, congestive heart failure, pulmonary embolism, myocarditis, myocardial contusion, and renal failure, should be considered when acute coronary syndromes are excluded 3.
• Angiotensin-converting enzyme (ACE) inhibition has been shown to reduce troponin release in non-ST-elevation acute coronary syndrome (ACS) 4.
• Antiplatelet intervention, including aspirin, clopidogrel, and glycoprotein IIb/IIIa inhibitors, is crucial in the management of acute coronary syndrome 5.
• Lowering the diagnostic threshold of plasma troponin concentration may identify more patients with acute coronary syndrome at risk of recurrent myocardial infarction and death, but would increase the diagnosis of myocardial infarction by 47% 6.

Key Considerations

• Troponin elevation in the absence of thrombotic acute coronary syndromes still retains prognostic value 3.
• The underlying cause of troponin elevation should be targeted, rather than treating with antithrombotic and antiplatelet agents 3.
• Combining glycoprotein IIb/IIIa inhibition with drug-eluting stents may optimize outcomes after revascularization in patients with diabetes 5.
• Increasing adherence to American College of Cardiology/American Heart Association guidelines is key to improving outcomes in patients with acute coronary syndrome 5.