Would it be pertinent to get troponin (cardiac enzyme) and D-dimer (fibrin degradation product) levels in a patient with shortness of breath and recent use of nortriptyline (nortriptyline hydrochloride)?

From the Guidelines

Yes, it would be pertinent to obtain both troponin and D-dimer levels in a patient presenting with shortness of breath who is taking nortriptyline. Nortriptyline, a tricyclic antidepressant, can cause cardiovascular side effects including tachycardia, arrhythmias, and in overdose situations, myocardial injury 1. Troponin testing would help evaluate for possible myocardial damage or acute coronary syndrome, which could be contributing to or causing the shortness of breath. Additionally, tricyclic antidepressants like nortriptyline may increase the risk of thromboembolism in some patients. D-dimer testing would help assess for possible pulmonary embolism, which is an important differential diagnosis in patients with acute shortness of breath. The combination of these tests, along with other clinical assessments such as vital signs, physical examination, ECG, and chest imaging, would provide valuable diagnostic information to determine the cause of shortness of breath in this patient. If either test returns positive, further specific testing (such as cardiac imaging for elevated troponin or CT pulmonary angiography for elevated D-dimer) would be indicated based on the clinical context, as recommended by recent guidelines 1.

Some key points to consider:

• Troponin levels should be measured at presentation and repeated 6-9 hours later to evaluate for myocardial injury 1.
• D-dimer testing can help assess for pulmonary embolism, but it is not specific and can be elevated in other conditions 1.
• The use of clinical prediction scores and imaging studies, such as CT pulmonary angiography, can help further evaluate patients with suspected pulmonary embolism 1.
• The management of patients with acute coronary syndromes and pulmonary embolism requires a multidisciplinary approach and adherence to established guidelines 1.

Overall, obtaining troponin and D-dimer levels, along with other diagnostic tests and clinical assessments, is crucial in evaluating patients with shortness of breath who are taking nortriptyline, to determine the underlying cause and guide appropriate management.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Troponin and D-Dimer Levels in Patients with Shortness of Breath

• Troponin levels can be elevated in various conditions, including sepsis, hypovolemia, atrial fibrillation, congestive heart failure, pulmonary embolism, myocarditis, myocardial contusion, and renal failure, not just thrombotic acute coronary syndromes 2.
• D-dimer levels can be used to exclude pulmonary embolism (PE) in outpatients with suspected PE, with a negative predictive value of 99% for a D-dimer concentration below 500 micrograms/L 3.
• Elevated troponin I and D-dimer levels have been associated with increased mortality and need for intensive care in patients with COVID-19 pneumonia 4.
• Sensitive cardiac troponin assays can improve the early diagnosis of acute myocardial infarction, particularly in patients with a recent onset of chest pain 5.
• The D-dimer/troponin ratio can be a useful parameter for differentiating acute pulmonary embolism from non-ST elevation myocardial infarction, with an optimal cut-off value of 1.82 for differentiating the two conditions 6.

Considerations for Troponin and D-Dimer Testing

• Troponin levels should be interpreted in the context of the patient's clinical presentation and other diagnostic tests, as elevations can occur in various conditions.
• D-dimer levels can be used to exclude pulmonary embolism, but a positive result does not necessarily confirm the diagnosis.
• The D-dimer/troponin ratio may be a useful tool for differentiating between acute pulmonary embolism and non-ST elevation myocardial infarction.
• The use of sensitive cardiac troponin assays can improve the early diagnosis of acute myocardial infarction.
• Elevated troponin I and D-dimer levels can be associated with increased mortality and need for intensive care in certain patient populations.

Relevance to the Patient with Shortness of Breath and Recent Use of Nortriptyline

• Given the patient's symptoms of shortness of breath and recent use of nortriptyline, it may be pertinent to measure troponin and D-dimer levels to help diagnose or exclude conditions such as pulmonary embolism or acute myocardial infarction 2, 3, 6.
• The patient's troponin and D-dimer levels should be interpreted in the context of their clinical presentation and other diagnostic tests.
• The D-dimer/troponin ratio may be a useful tool for differentiating between acute pulmonary embolism and non-ST elevation myocardial infarction in this patient 6.