Clinical predictors of pulmonary hypertension in sarcoidosis

Abstract

Pulmonary hypertension (PH) adversely affects outcome in sarcoidosis and is an important predictor of mortality in these patients. Early and accurate diagnosis of this complication may improve outcome. The current authors hypothesised that integration of 6-min walk test (6MWT) as part of the evaluation leads to an earlier diagnosis of this complication. A total of 162 patients with sarcoidosis underwent 6MWT. Demographic and pulmonary function results were analysed. Patients were further assessed by echocardiography and right heart catheterisation when clinically indicated. Patients with sarcoidosis-associated PH had significantly decreased results on pulmonary function testing. They also walked shorter distances and desaturated to lower levels on 6MWT. On logistic regression analyses, significant predictors of PH were oxygen saturation <90% on 6MWT (odds ratio (OR) 12.1, 95% confidence interval (CI) 3.66-19.73) and diffusing capacity of the lung for carbon monoxide <60% predicted (OR 7.3, 95% CI 1.98-24.82). Moreover, by combining the results of oxygen saturation at 6 min with those of echocardiography, the ability to correctly predict the presence of PH by right heart catheterisation was improved. Patients with diffusing capacity of the lung for carbon monoxide <60% predicted and oxygen desaturation <90% on 6-min walk test have a high likelihood of pulmonary hypertension and should undergo further evaluation for the presence of this disorder.