Epidemiology and mortality of connective tissue disease-associated pulmonary arterial hypertension: A national cohort study in taiwan

Objective: To estimate and compare the incidence and survival impact of pulmonary arterial hypertension (PAH) among patients with various connective tissue diseases (CTDs). Methods: We used a national health insurance database in Taiwan and enrolled patients with incident systemic sclerosis (SSc), systemic lupus erythematosus (SLE), primary Sjögren's syndrome (pSS), polymyositis/dermatomyositis (PM/DM) and rheumatoid arthritis (RA) between 2002 and 2013. We calculated the cumulative incidence of PAH and the probability of survival after PAH diagnosis by the Kaplan-Meier method. Results: Of 1653 SSc patients, 127 (7.68%) developed PAH. Of 11,735 SLE patients, 242 (2.06%) developed PAH. Of 17,316 pSS patients, 1811 PM/DM patients, and 32,296 RA patients, 38 (0.22%), 6 (0.33%) and 15 (0.04%) patients developed PAH, respectively. The most common CTD among all CTD-PAH patients was SLE (57%), followed by SSc (30%), pSS (9%), RA (3%) and PM/DM (1%). The 1-, 3- and 5-year survival rates for SSc-PAH were 88.3%, 72.1% and 61.9%, respectively. The 1-, 3- and 5-year survival rates for SLE-PAH were 87.6%, 75.8% and 69.4%, respectively. The 1-, 3- and 5-year survival rates for pSS-PAH were 90.8%, 86.8% and 80.6%, respectively. Conclusions: SLE was the most common underlying CTD, followed by SSc, in the total CTD-PAH population. However, the highest risk of developing PAH was observed in the SSc groups. PAH is a very rare complication in pSS, PM/DM and RA. Patients with SSc-PAH have the worst survival rate compared to those with SLE-PAH or pSS-PAH.