Combined measurement of carbon monoxide and nitric oxide lung transfer does not improve the identification of pulmonary hypertension in systemic sclerosis.

Screening is important to determine whether patients with systemic sclerosis (SSc) have pulmonary hypertension because earlier pulmonary hypertension treatment can improve survival in these patients. Although decreased transfer factor of the lung for carbon monoxide () is currently considered the best pulmonary function test for screening for pulmonary hypertension in SSc, small series have suggested that partitioning into membrane conductance (diffusing capacity) for carbon monoxide () and alveolar capillary blood volume () through combined measurement of and transfer factor of the lung for nitric oxide () is more effective to identify pulmonary hypertension in SSc patients compared with alone. Here, the objective was to determine whether combined - partitioned with recently refined equations could more accurately detect pulmonary hypertension than alone in SSc.