Background: Pulmonary arterial hypertension (PAH) has been identified as a life threatening complication of connective tissue disease. However, the association between serum uric acid (UA) levels and long-term outcome in PAH with connective tissue disease has not been evaluated. We therefore assessed whether serum UA levels are related to the mortality of such patients.
Methods and results: We investigated 90 consecutive patients with connective tissue disease who were initially diagnosed with PAH by echocardiography, and assessed the long-term clinical outcome in populations with higher (> or = 4.7 mg/dL) and lower serum UA levels. Kaplan-Meier analysis showed that patients with higher median serum UA values had a significantly worse survival rate for any cause of death (54.5% versus 84.7%, log-rank, P < 0.01) and PAH-related death (72.7% versus 93.4%, log-rank, P < 0.01) than those with low values. Multivariate analysis showed that an elevated serum UA level was an independent predictor for survival (hazard ratio, 1.88, 95% CI [1.24- 2.84], P < 0.01).
Conclusion: Elevated serum UA levels are associated with a poor prognosis and can serve as a prognostic predictor for patients with PAH secondary to connective tissue disease.