Comparison of Baseline Characteristics and Survival Between Patients With Idiopathic and Connective Tissue Disease–related Pulmonary Arterial Hypertension

Background Both idiopathic pulmonary arterial hypertension (IPAH) and pulmonary arterial hypertension (PAH) related to connective tissue diseases (CPAH) are classified in the group of PAH disorders. However, CPAH has a particularly worse prognosis than IPAH. Few studies have compared the clinical, functional and hemodynamic profiles of IPAH and CPAH. Methods We performed a retrospective cohort study of patients with IPAH or CPAH. Demographic characteristics, functional status (FE), pulmonary function test and hemodynamic values at the time of diagnosis were compared between the two etiologies. Global cumulative survival rates free from transplantation (SFT) and survival according to date of diagnosis were analyzed. Results Despite similar PAH severity, patients with CPAH showed a more severe baseline impairment of 6-minute walking test (6MWT) (307 ± 116 m vs 378 ± 101 m) and diffusion capacity of the lung for carbon monoxide (DLCO) (57 ± 25% vs 75 ± 30% of predicted) than IPAH ( p p p = 0.01). However, CPAH showed a poorer prognosis than IPAH in the more recent era ( p Conclusions Despite similar functional and hemodynamic severity, patients with CPAH showed a more severe baseline impairment of 6MWT and DLCO and worse overall prognosis than IPAH. Both IPAH and CPAH survival improved in the current era. Nevertheless, CPAH still showed a poorer prognosis than IPAH.