Diagnosis of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is the only potentially curable form of pulmonary hypertension (PH) and a rapid and accurate diagnosis is pivotal for successful treatment. Current guidelines recommend that all patients with suspected CTEPH be referred to an expert centre for an accurate differential diagnosis and evaluation of the best treatment strategy to be performed by a multidisciplinary team. Ventilation/perfusion (V/Q) lung scan remains the screening method of choice; a normal scan rules out CTEPH. Despite the status of high-quality pulmonary angiography as the gold standard, techniques such as computed tomography pulmonary angiography (CTPA) and magnetic resonance imaging (MRI) are increasingly used for characterising the pulmonary vasculature and assessment of operability. Although there is increasing interest in non-invasive haemodynamic evaluation, given the complexity of pathophysiologic changes occurring in CTEPH, right-heart catheterisation (RHC) is still mandatory to confirm the diagnosis of pulmonary arterial hypertension (PAH) and to assess the degree of haemodynamic impairment. This chapter describes the diagnostic workup that is commonly used in clinical practice and recommended in the scientific literature.