Pulmonary Artery Dimensions as a Prognosticator of Transplant-Free Survival in Scleroderma Interstitial Lung Disease.

ABSTRACT

BACKGROUND: Systemic sclerosis is a chronic debilitating autoimmune disease characterized by endothelial dysfunction and multi-organ fibrosis. Interstitial lung disease, a common manifestation of SSc, is termed scleroderma-related interstitial lung disease (SSc-ILD) and along with pulmonary hypertension contributes to a majority of deaths in SSc. SSc-ILD patients frequently develop pulmonary hypertension, which prognosticates a poorer outcome. We investigated pulmonary artery dimensions as an outcome predictor in patients with SSc-ILD. METHODS: A retrospective chart review abstracting data from SSc-ILD patients evaluated at a large tertiary care center was performed. HRCT imaging was reviewed and pulmonary artery (PA) and ascending aorta (Ao) diameters were measured for calculation of the PAAo ratio. Additionally, demographics, vital signs, spirometric parameters, comorbidities, and mean pulmonary artery pressures were collected when available. Outcome analysis with lung transplant or death events within 4 years based on pulmonary artery size as well as PAAo ratio was performed. RESULTS: 70 SSc-ILD patients were identified. Mean pulmonary artery diameter and PAAo ratio was 31.17 and 1.07 mm, respectively. Patients with a pulmonary artery diameter ≥32 mm had higher risk of lung transplantation or death (p < 0.001) within 4 years. Patients with a PAAo ratio ≥1.1 also had higher risk of lung transplantation or death (p < 0.001) within 4 years. Unadjusted outcomes analyses also identified PAAo ratio ≥1.1 as an independent outcome predictor (hazard ratio 3.30, p < 0.001). CONCLUSIONS/CLINICAL IMPLICATIONS In SSc-ILD patients, a PAAo ratio ≥1.1 is associated with higher risk of lung transplant or death. These data suggest that PAAo dimension may be used for prognostication in SSc-ILD.