SYSTEMIC SCLEROSIS-ASSOCIATED PRECAPILLARY PULMONARY HYPERTENSION WITH AND WITHOUT INTERSTITIAL LUNG DISEASE: OBSERVATIONS FROM A SINGLE REFERRAL CENTER COHORT

Abstract

SESSION TITLE: Diffuse Lung Disease Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Interstitial lung disease (ILD) and precapillary pulmonary hypertension (PH) are the leading causes of morbidity and mortality in systemic sclerosis (SSc). However, whether PH is more frequent in SSc in the presence of ILD, and whether it confers an increased risk of death remains incompletely understood. METHODS: Analysis of data from SSc patients followed between 2017-2019 at the UCMC. Details regarding the presence, type and severity of ILD were obtained from HRCTs and PFTs. Precapillary pulmonary hypertension was diagnosed by RHC in accordance with guidelines (mPAP >25 mmHg, PCWP =15 mmHg and a PVR >3 WU). Continuous data were summarized as median(IQR), and count data were summarized as percentages. Cox proportional-hazards model was used to calculate hazard ratios for survival. RESULTS: We reviewed data from 184 SSc patients. Median age was 58 years (IQR 19), and the majority of the subjects were women (84%). HRCT scans were available for 169/184 (92%) of patients, with 78/169 (46%) having radiological ILD. Non-specific interstitial pneumonia was the most frequent radiographic pattern, seen in 60% of patients. Patients with ILD had worse pulmonary function compared to patients without ILD. Indeed, both FVC (76% predicted, IQR 31 vs 82% predicted, IQR 31) and DLCO (52% predicted, IQR 27 vs 72%predicted, IQR 41) were significantly lower in SSc patients with ILD compared to those without ILD. PH was more common in patients with ILD (35% vs 21%, p<0.05). However, the median mPAP was similar between both subsets (35mmHg vs 31mmmHg, in patients with versus without ILD, respectively). Similarly, we did not find a statistically significant difference in PVR, right atrial pressure or cardiac index. Amongst patients with ILD, 51% received an immunomodulator other than prednisone. Mycophenolate mofetil (MMF) was used in 36/78 (46%) of patients. Although numerically higher, there was no statistical difference in FVC between ILD patients who took MMF versus those who did not (74% predicted, IQR 36 vs 70% predicted, IQR 32, p = 0.361). In patients with combined ILD-PH, we found no correlation between mPAP and DLCO or FVC. We found no differences in mPAP or PVR between patients taking MMF versus those not taking it. Similarly, we found no difference in the percentage change in FVC between patients taking MMF versus those without. During our follow-up time, 15/78 (19.2%) ILD patients died and 8/78 (10.3%) were lost to follow up. The presence of PH was associated with a significantly higher risk of death (HR 3.69, 95%CI 1.26-10.81) in SSc patients with ILD. However, this increased hazard risk was no longer statistically significant when adjusted for FVC and DLCO. CONCLUSIONS: PH was more common in SSc patients with ILD compared to those without. Although the presence of PH may confer an increased risk of death, it does not appear to be independent of low FVC or DLCO. CLINICAL IMPLICATIONS: Prognosis of SSc-ILD DISCLOSURES: No relevant relationships by Yousef Ahmad, source=Web Response Chair of a Committee relationship with PHA Please note: PHA Medically Led Sessions, PHA Preceptorship Added 05/22/2020 by Jean Elwing, source=Web Response Removed 05/22/2020 by Jean Elwing, source=Web Response Educator relationship with PH CME Programs - PHA, Simply Speaking, Impact PH Please note: Intermittent, Ongoing Added 05/22/2020 by Jean Elwing, source=Web Response, value=Honoraria Principal Investigator relationship with Actelion, Arena, Reata, United Therapeutics Please note: Ongoing - University is Paid Directly Added 05/22/2020 by Jean Elwing, source=Web Response, value=Grant/Research Support Advisory Committee Member relationship with United Therapeutics Please note: $5001 - $20000 Added 06/05/2020 by Jean Elwing, source=Web Response, value=Consulting fee Principal Investigator relationship with Lung LLC, Liquidia, Phase Bio, Complexa, Gossamer Bio Please note: Ongoing - University is Paid Directly Added 05/22/2020 by Jean Elwing, source=Web Response, value=Grant/Research Support Member of a Committee relationship with PHA Please note: PHA Education Committee Added 05/22/2020 by Jean Elwing, source=Web Response Removed 05/22/2020 by Jean Elwing, source=Web Response Advisory Committee Member relationship with Liquidia, Acceleron Please note: $1001 - $5000 Added 06/05/2020 by Jean Elwing, source=Web Response, value=Consulting fee Advisory Committee Member relationship with Acceleron Please note: $5001 - $20000 Added 06/05/2020 by Jean Elwing, source=Web Response, value=Consulting fee Removed 06/05/2020 by Jean Elwing, source=Web Response No relevant relationships by Jose Gomez-Arroyo, source=Web Response No relevant relationships by Nishant Gupta, source=Web Response No relevant relationships by Sarah Khan, source=Web Response No relevant relationships by Keegan Olmstead, source=Web Response No relevant relationships by Julie Windholz, source=Web Response No relevant relationships by Christine Zhou, source=Web Response