LAUSR

Background Digital ulcers (DUs) are common manifestations of vascular disease in systemic sclerosis (Ssc) patients. Objectives To investigate the association between the amount of oxygen delivered to periferal tissues and the development of DUs in SSc patients. Methods One hundred and eleven SSc patients (103 female) were recruited consecutively to the study. Thirty age and sex matched controls were also enrolled. Transthoracic echocardiography (TTE) was performed for each patient to estimate cardiac output (CO). Arterial oxygen saturation (SaO2) with pulse oximeter in room temperature and serum haemoglobin concentration (Hb) were measured at the time of TTE. The amount of oxygen delivered to tissues (D02) in 1 min was estimated using the equation D02=CO*(SaO2*1.39*Hb) and adjusted for body weight. Demographic, clinical and laboratory data were retrieved from hospital records. DUs were described as ulcerations on the skin distal to proksimal interphalangeal joints (PIF) of the digits. Patients were divided into 2 groups according to presence of DUs wıthin 1 year of study enrollment (Group1=with DU, Group2=without DU). Chi-square and Mann-Whitney U tests were used for comparing categorical and continuous variables between the groups, respectively. Results Mean age was 52.6 (11.8) years in SSc patients and 51.3 (13.0) in controls. Median disease duration was 138.0 (1.8–415.2) months. Diffuse disease was present in 30.6% of patients. There were no differences in terms of Hb level, left ventricular ejection fraction (LVEF) and calculated D02 between SSc patients and controls. Mean CO was higher in healthy controls (6.1 vs. 5.1, p=0.004). İnterestingly, mean S02 measurements was lower in control group (96.8 vs. 98.0, p=0.005). Comparison of demographics, disease characteristics, tissue oxygen delivery and relevant variables were summarised in table 1. When patients with active DUs were compared with patients without active DUs; no difference was found in Hb,S02, CO and D02 between groups.Abstract FRI0425 – Table 1 Comparison of demographics, disease characteristics and DO2 parameters between patients with and without DUs Conclusions Although the haemoglobin concentration was higher in the non ulcer group, there was no difference in the amount of delivered oxygen between patients with and without DUs. These findings imply that vasculopathy and/or peripheral artery disease plays a major role in the development of ulcers. Disclosure of Interest None declared