Predictors and prognosis of pulmonary hypertension complicating interstitial lung disease in systemic sclerosis

OBJECTIVE: The objective of this study was to identify those SSc patients with concurrent pulmonary hypertension (PH) (SSc-PH patients) and interstitial lung disease (ILD) and determine their disease severity, therapeutic approach, and survival. METHODS: Consecutive SSc patients enrolled in the Australian Scleroderma Cohort Study (ASCS) who were diagnosed with pulmonary hypertension (via right-heart catherization) were included in the study. Logistic regression was used to determine the associations of ILD with PH hemodynamic parameters and therapeutic approach. Kaplan-Meier survival curves were used to estimate survival rates. RESULTS: Of 1883 SSc patients, 164 (8.7%) developed incident PH over a median follow-up of 4.3 (1.7-7.9) years. Of these, 43.9% had concurrent ILD at PH diagnosis (PH-ILD) and 56.1% had group 1 pulmonary arterial hypertension (PAH). Extensive ILD was present at PH diagnosis in 40.3%. Despite these distinct PH cohorts, a similar frequency of each PH cohort was treated with vasodilatory therapy at PH diagnosis, regardless of the presence or severity of ILD. The majority (87.5%) of those patients with extensive ILD and PH received upfront vasodilatory therapy at PH diagnosis, with no difference in its tolerability or therapy cessation being observed compared with the patients with group 1 PAH. Although vasodilator therapy was not associated with a survival advantage in those with extensive ILD, its use was associated with an amelioration of symptoms, and an improvement in physical function, and quality of life (QoL). CONCLUSION: Despite vasodilator therapy, survival in SSc-PH was found to be poor, with the presence of concurrent ILD being associated with worse survival. Although vasodilator therapy commenced at PH diagnosis was not shown to be associated with an improved survival in PH with extensive ILD, it appeared to be well tolerated and may improve symptoms, physical function, and QoL.