Pulmonary hypertension complicating sarcoidosis.

Pulmonary hypertension is a challenging complication of sarcoidosis, which reported rates of prevalence largely depend on the advancement of pulmonary disease. About 6% of unselected sarcoidosis patients suffer from PH. Although destruction of the distal capillary bed and resultant hypoxemia are important, the mechanisms of sarcoidosis-PH are multifactorial, including specific vasculopathy, local increased vasoreactivity, extrinsic compression of pulmonary vessels and portal hypertension. As a result, a proportion of patients exhibit "out of proportion" PH, i.e. more severe than expected from functional impairment (mean PAP>35-40mmHg). The sarcoidosis vasculopathy prevails in the venous side, reflecting the spreading of granulomatous process, and can cause pulmonary veno-occlusive disease. The responsibility of left-heart dysfunction is probably underestimated by echocardiography. There is no validated screening algorithm for the detection of sarcoidosis-PH but recent studies have underlined the role of right heart catheterisation to exclude post-capillary PH. PH carries a poor prognosis in sarcoidosis patients, with a significantly increased morbidity and mortality. Management of sarcoidosis-PH mainly relies on supportive therapy (supplemental oxygen and diuretics as needed) and lung transplantation in otherwise eligible patients. Rare cases of sarcoidosis-PH with nonfibrotic pulmonary disease respond to corticosteroids. Data on the efficacy and safety of PAH agents are scarce and discrepant. Further controlled trials are warranted and should integrate the concept of disproportionate PH in their design.