An evidence-based approach to screening and diagnosis of pulmonary hypertension

Pulmonary hypertension (PH) continues to be a devastating disease, with a poor prognosis and high mortality rate if not treated early. Unfortunately, most patients are still diagnosed late in the course of the disease. Therefore, it is crucial to have a low threshold for suspecting PH and to refer patients early to specialized centres for diagnostic workup and management. In this article we focus on updated evidence-based screening and diagnosis in adults, based on the fifth World Symposium on Pulmonary Hypertension in 2013. The updated hemodynamic definition of PH includes a pulmonary vascular resistance > 3 Wood units. A new component to the hemodynamic definition of PH has been proposed in left heart disease, based on a diastolic pulmonary gradient (diastolic pulmonary arterial pressure - mean pulmonary artery wedge pressure), > 7 mm Hg. The term "borderline PH" for mean pulmonary artery pressures 21-24 mm Hg is discouraged, with emphasis on its significance for careful follow-up in high-risk patients, especially in systemic sclerosis. Annual pulmonary arterial hypertension (PAH) screening with a 2-step algorithm is recommended in asymptomatic systemic sclerosis patients. An updated simplified PH diagnostic algorithm approach is proposed. Genetic testing reveals mutations in bone morphogenic protein receptor type II in 70% of familial PAH, and is useful for screening asymptomatic family members. Important associated conditions that should be considered include thyroid disease, left heart disease, toxic causes, lung diseases (including pulmonary thromboembolism), hemolytic anemia, and human immunodeficiency virus infection. Biomarkers have been identified that correlate with PAH severity and mortality and are useful in follow-up.