What is the justification for ordering a computed tomography (CT) scan of the chest for a patient with chronic cough and chest tightness to evaluate for Pulmonary Hypertension (PHTN)?

From the Guidelines

A CT chest is not justified for the initial evaluation of a patient with chronic cough and chest tightness, as the evidence suggests that chest radiography is the recommended initial imaging modality for patients with chronic cough lasting >8 weeks with no known risk factors for lung cancer 1. However, if the patient has persistent symptoms despite initial clinical evaluation and empiric treatment, or if there are concerning clinical features, a CT chest with or without IV contrast may be considered as a complementary imaging modality to chest radiography 1. The decision to order a CT chest should be based on a thorough clinical evaluation and consideration of the patient's individual risk factors and symptoms, rather than as a routine initial imaging study for chronic cough. It is also important to note that the use of CT chest in the evaluation of chronic cough is not well established, and the evidence is limited to case series and observational studies 1. Therefore, the ordering of a CT chest for a patient with chronic cough and chest tightness should be done judiciously and with consideration of the potential benefits and risks of the examination, including radiation exposure. In general, a stepwise approach to imaging, starting with chest radiography and proceeding to more advanced imaging modalities such as CT chest only if necessary, is a reasonable approach to the evaluation of patients with chronic cough 1.

Some key points to consider when evaluating a patient with chronic cough and chest tightness include:

• The patient's medical history and risk factors for lung disease, such as smoking or exposure to environmental pollutants 1
• The presence of concerning clinical features, such as dyspnea, chest pain, or weight loss 1
• The results of initial clinical evaluation and empiric treatment, including chest radiography and pulmonary function tests 1
• The potential benefits and risks of advanced imaging modalities, such as CT chest, including radiation exposure and the potential for incidental findings 1

By considering these factors and using a stepwise approach to imaging, clinicians can make informed decisions about the use of CT chest and other imaging modalities in the evaluation of patients with chronic cough and chest tightness.

From the Research

Evaluation for Pulmonary Hypertension

• Pulmonary hypertension is a progressive and often fatal disease that can present with symptoms such as dyspnea on exertion, chronic cough, and chest tightness 2.
• Transthoracic echocardiography (TTE) has a central role as a screening tool in those with symptoms and those at risk for developing pulmonary vascular disease, but it may not be sufficient for a formal diagnosis 2.

Justification for CT Chest

• A combination of TTE and chest CT may offer a better way of identifying pulmonary hypertension than either one alone, with a sensitivity of 98% and specificity of 70% 3.
• Chest CT is more helpful in excluding the causes of long-term cough, such as bronchial tumors and pulmonary interstitial diseases, and may be recommended as a first-line examination for patients with chronic cough 4.
• CT chest can help identify potential causes of pulmonary hypertension, such as chronic thromboembolic pulmonary hypertension, which is associated with a poor prognosis if left untreated 5.

Diagnostic Approach

• The diagnostic approach for pulmonary hypertension aims at assessing the location and extent of the embolic obstruction, establishing the operability and prognosis of the patients, and ruling out other variations of pulmonary hypertension with distinct indicated treatment 5.
• A ventilation-perfusion scan is recommended as a first-line modality for suspected chronic thromboembolic pulmonary hypertension, but many patients with pulmonary embolism do not undergo imaging tests that could diagnose pulmonary hypertension or chronic thromboembolic pulmonary hypertension 6.
• Ordering a CT chest for a patient with chronic cough and chest tightness may be justified as part of a comprehensive diagnostic approach to evaluate for pulmonary hypertension and other potential causes of their symptoms 3, 4.