Esophageal Dilation and Other Clinical Factors Associated with Pulmonary Function Decline in Patients with Systemic Sclerosis.

Abstract

OBJECTIVE\nTo identify clinical factors, including esophageal dilation on chest high-resolution computed tomography (HRCT), that are associated with pulmonary function decline in patients with systemic sclerosis (SSc).\n\n\nMETHODS\nPatients fulfilled 2013 SSc criteria and had ≥1 HRCT and ≥2 pulmonary function tests (PFTs). According to published methods, widest esophageal diameter (WED) and radiographic interstitial lung disease (ILD) were assessed, and WED was dichotomized as dilated (≥19mm) vs. not dilated (<19mm). Clinically meaningful PFT decline was defined as %-predicted change in forced vital capacity (FVC) ≥5 and/or diffusion capacity for carbon monoxide (DLCO) ≥15. Linear mixed effect models were used to model PFT change over time.\n\n\nRESULTS\n138 SSc patients met study criteria: 100 (72%) had radiographic ILD; 49 (35%) demonstrated FVC decline (median follow-up 2.9y). Patients with Scl-70 autoantibodies had 5- year %-predicted FVC decline (-6.3; 95% CI -9.9, -2.8), while patients without Scl-70 autoantibodies demonstrated 5-year FVC stability (+1.78; 95% CI -0.6, 4.15). Esophageal diameter did not distinguish between those with vs. without FVC decline. Patients with esophageal dilation had statistically significant 5-year %-predicted DLCO decline (-5.6; 95% CI - 10.0, -1.2), but this decline was unlikely clinically significant. Similar results were observed in sub-analysis of patients with radiographic ILD.\n\n\nCONCLUSION\nIn patients with SSc, Scl-70 positivity is a risk factor for %-predicted FVC decline at five years. Esophageal dilation on HRCT was associated with a minimal, non-clinically significant decline in DLCO and no change in FVC during 5-year follow-up. These results have prognostic implications for SSc-ILD patients with esophageal dilation.