Initial investigations for a patient suspected of having pulmonary hypertension should begin with a thorough clinical assessment including history and physical examination to identify signs such as peripheral oedema, raised venous pressure, a systolic parasternal heave, and a loud pulmonary second heart sound, which may suggest cor pulmonale or pulmonary hypertension NICE NG115.
Basic investigations in primary care include measurement of oxygen saturation by pulse oximetry to assess for hypoxia, a full blood count to exclude anaemia or polycythaemia, and chest radiography to evaluate for lung disease or heart failure NICE CKS. Spirometry should be performed to assess for underlying chronic obstructive pulmonary disease or other airway diseases that may contribute to pulmonary hypertension NICE NG115. Electrocardiography (ECG) is recommended to exclude arrhythmias and assess for right heart strain or cor pulmonale features NICE CKS,NICE NG115.
Serum natriuretic peptides, such as NT-proBNP, should be measured to assess cardiac strain and help differentiate heart failure, which can coexist or mimic pulmonary hypertension NICE NG106,NICE NG115. Elevated levels warrant urgent specialist referral and echocardiography.
Echocardiography is the key non-invasive imaging investigation to assess cardiac function, estimate pulmonary artery pressures, and evaluate for left heart disease or valvular pathology contributing to pulmonary hypertension NICE CKS,NICE NG115. Ultrasonography may also be used to exclude pleural effusion NICE CKS.
In cases where pulmonary embolism is suspected, computed tomography pulmonary angiography (CTPA) should be performed to exclude thromboembolic disease NICE CKS. Further imaging such as high-resolution CT may be indicated to evaluate for parenchymal lung disease or other causes.
These initial investigations aim to identify the underlying cause of pulmonary hypertension, guide referral to specialist centres, and initiate appropriate management. Recent literature emphasizes the importance of a comprehensive approach including biomarkers and imaging to stratify risk and tailor therapy in pulmonary arterial hypertension Boucly et al. 2023.