Pos1277 lung function associated with subclinical myocardial impairment in systemic sclerosis: a cardiac magnetic resonance study

Background Systemic sclerosis (SSc) is an autoimmune disease and microvasculopathy is its major pathophysiological process. Patients with SSc usually have abnormal immune activation, neovascularization, and vascular remodeling. Progressive fibrosis and dysfunction will occur in multiple organs along with the progression of diseases, such as interstitial lung disease and cardiomyopathy [1]. Myocardial impairment is the major cause of death in patients with SSc [2]. Cardiac magnetic resonance (CMR) has been demonstrated to be an ideal non-invasive modality to assess myocardial pathology, particularly quantitative T1 [3]. However, CMR is not applicable for individuals with contraindications to MR examination. Objectives This study aimed to investigate the association between lung function and myocardial T1 values using cardiac magnetic resonance (CMR) in SSc patients without cardiovascular symptoms. Methods The SSc patients without cardiovascular symptoms and age- and sex-matched healthy subjects were recruited and underwent CMR examination to acquire CINE and T1 mapping images. Myocardial native T1 values and lung function were evaluated. Spearman’s rank correlations and linear regression analyses were conducted to determine the association between lung function and myocardial native T1 values. Results Forty SSc patients (mean age 47.7±13.8 years, 35 females) and 13 (mean age 43.2±3.3 years,10 females) healthy subjects were enrolled. SSc patients showed significantly higher native T1 value in myocardium compared to healthy subjects (1305±48.3 ms vs. 1273.7±35.5 ms, P=0.036). Diffusing capacity of lungs for carbon monoxide (DLCO) was significantly associated with myocardial native T1 value before (β, -0.958; 95%CI, -1.822 to -0.094; P=0.031) and after adjusted for confounding factors (β, -1.223; 95%CI, -2.155 to -0.291; P=0.012). Moderate-to-severe decrease of DLCO (DLCO<60%) was independently associated with myocardial native T1 value (β, 33.189; 95%CI, 16.332 to 50.046; P=0.001). Figure 1 presents a typical case about myocardial native T1 value in a SSc patient (DLCO<60%) and an age- and sex-matched healthy subject. Conclusion Lung function is independently associated with myocardial native T1 values in SSc patients, particularly for moderate-to-severe decrease of DLCO, suggesting that lung function measurements might be a potential indicator for subclinical myocardial impairment in SSc patients. It is well established that chronic inflammation, the major pathophysiological process of SSc in early stage, persistently activates interstitial fibroblasts of multiple organs including lung and heart, leading to the irreversible fibrosis and subsequent decline of function [4]. References [1]Katsumoto TR, Whitfield ML, Connolly MK. The pathogenesis of systemic sclerosis. Annu Rev Pathol 2011;6:509-37. [2]Komócsi A, Vorobcsuk A, Faludi R, et al. The impact of cardiopulmonary manifestations on the mortality of SSc: A systematic review and meta-analysis of observational studies. Rheumatology (Oxford) 2012;51:1027-36. [3]Agoston-Coldea L, Zlibut A, Revnic R, Florea M, Muntean L. Current advances in cardiac magnetic resonance imaging in systemic sclerosis. Eur Rev Med Pharmacol Sci 2021;25:3718-36. [4]Asano Y. The pathogenesis of systemic sclerosis: An understanding based on a common pathologic cascade across multiple organs and additional Organ-Specific pathologies. J Clin Med 2020;9:2687. Figure 1 : A 59 years old female SSc patient with declined DLCO (54%) and elevated myocardial native T1 (1327ms) (a-c); Images d-f showed the native T1 maps of myocardium of a 57 years old female healthy subject with the mean T1 value of 1255ms. The MR images of T1 maps of myocardium were taken from short axis slices of left ventricle. nT1, native T1 value. Figure 1 Native T1 value measured by cardiac magnetic resonance in a SSc patient and a healthy subject. Acknowledgements: NIL. Disclosure of Interests None Declared.