Incidence and prognostic significance of pleural effusions in pulmonary arterial hypertension

It has been suggested pleural effusions may develop in right heart failure in the absence of left heart disease. The incidence and prognostic significance of pleural effusions in pulmonary arterial hypertension is uncertain. Patients with pulmonary arterial hypertension followed at our tertiary care center were reviewed. Survival was examined based on the subsequent development of a pleural effusion. A total of 191 patients with pulmonary arterial hypertension met the inclusion criteria. The prevalence of pleural effusions on initial assessment was 7.3%. Among patients without a pleural effusion on initial imaging and at least one follow-up computerized tomography (N = 142), pleural effusion developed in 27.5% (N = 39) of patients. No alternative etiology of the effusion was identified in 19 (48.7%) cases and effusions deemed related to pulmonary arterial hypertension occurred at an incident rate of 38.6 cases per 1000 person-years. Of these, 14 (73.7%) were bilateral, 3 (15.8%) were right-sided, and 2 (10.5%) were left-sided. Effusion size was trace or small in 18 patients (94.7%). Development of a new pleural effusion was associated with attenuated survival in unadjusted survival analysis (HR: 3.80; 95% CI: 1.55–9.31), multivariate analysis (HR: 5.13; 95% CI: 1.86–14.16), and after the multivariate model was adjusted for concomitant pericardial effusion (HR: 4.86; 95% CI: 1.51–15.71). Negative impact on survival remained unchanged when effusions more likely related to an alternative cause were removed from analysis. In conclusion, pleural effusions can complicate pulmonary arterial hypertension in the absence of left heart disease. These effusions are frequently small in size, bilateral in location, and their presence is associated with decreased survival. Attenuated survival appears independent of the risk associated with a new pericardial effusion.