Natural history of mild-moderate pulmonary hypertension and the risk factors for severe pulmonary hypertension in scleroderma

Objective. To determine risk factors for developing pulmonary hypertension (PH) in patients with scleroderma (SSc, systemic sclerosis). Methods. We used a cohort of 1136 SSc patients using severe PH as the primary outcome in a natural history study. Results. Among 361 individuals with no initial echocardiographic PH, 92 (26.0%) developed mild-moderate PH and 48 (13.6%) severe PH. Patients developing severe PH had lower initial DLCO (48.8% of predicted) than those who did not develop PH (56.8% of predicted). Patients with mild-moderate PH had a 17% probability of progressing to severe PH, and 15.6% probability of regressing to no PH. Individuals with limited disease, mild-moderate PH, and age ≥ 47 years at diagnosis had a 27.3% probability of developing severe PH, compared to 8.5% in individuals with diffuse disease, no evidence of PH, and age < 47 years at diagnosis. Longitudinal regression models estimated that individuals with limited disease, mild-moderate PH, and DLCO < 50% predicted had an age-adjusted odds ratio of 8.6 of developing severe PH within 2 years compared to individuals without these risk factors. Conclusion. Development of severe PH is uncommon in certain subgroups of SSc patients. Risk factors for progression of PH include older age, limited skin disease, and elevated pulmonary artery pressures at the time of initial evaluation.