Frequency of pleural effusions in patients with pulmonary arterial hypertension associated with connective tissue diseases

Background: Pleural effusions frequently accumulate in patients with left-sided heart failure. However, our recent study in patients with idiopathic and heritable pulmonary arterial hypertension (PAH) demonstrated that pleural effusions frequently occur in patients with isolated right-sided heart failure (RHF). The objective of this study was to determine the frequency of pleural effusions in patients with PAH associated with connective tissue disease (CTD). Methods: We retrospectively studied consecutive patients with PAH associated with CTD who were treated in the Vanderbilt Pulmonary Vascular Center. Pleural effusions were identified by chest radiograph, chest CT scan, thoracic ultrasonography, or autopsy. Results: Thirty-five of 89 patients (39.3%) with PAH associated with CTD had pleural effusions: 23 of 51 (45.1%) with scleroderma, six of 16 (37.5%) with systemic lupus erythematosus, five of 18 (27.8%) with mixed connective tissue disease, and one of two (50.0%) with Sjögren syndrome. There were alternative explanations for the pleural effusions in six of these patients. Of the 29 patients without alternative explanation for their pleural effusions, 28 had RHF. When compared with the patients without pleural effusions, the 29 patients with pleural effusions had significantly higher mean right atrial pressures (11.3 ±5.1 mm Hg vs 8.3 ±4.0 mm Hg, P =.004) and lower cardiac indices (2.1 ±0.6 L/min/m² vs 2.5 ±0.7 L/min/m², P =.011). The pleural effusions were predominantly trace to small (58.6%) in size and bilateral (51.7%) in distribution. Conclusions: Pleural effusions frequently accumulate in patients with PAH associated with CTD and are associated with RHF.