POS0825 IMPACT OF LEFT VENTRICULAR DIASTOLIC DYSFUNCTION AND/OR CARDIAC AUTONOMIC DYSFUNCTION ON TISSUE OXYGENATION IN SYSTEMIC SCLEROSIS
Authors: G. S. Kart Bayram, U. N. Karakulak, A. Sari, B. Firlatan, M. Ekici, E. Ünaldi, G. Sandal Uzun, G. Ayan, L. Kiliç, A. Akdoğan
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Tissue oxygenation depends on the integrity of the microcirculation and the amount of oxygen delivery (DO2) to the systemic vascular bed. Cardiac function is one of the important components of tissue oxygenation[1]. Cardiac involvement in systemic sclerosis (SSc) can be seen in a wide spectrum, from subclinical involvement to heart failure[2]. <h3>Objectives:</h3> In this study, we aimed to investigate the impact of left ventricular diastolic dysfunction (LVDD) and/or cardiac autonomic dysfunction (CAD) on DO2 in SSc. <h3>Methods:</h3> Consecutive SSc patients who were admitted to the rheumatology outpatient clinic were included. All patients were evaluated for the presence of LVDD using transthoracic echocardiography, and cardiac output (CO) was calculated. 24-hour Holter electrocardiogram (ECG) monitoring was used to determine CAD. The DO2 was computed using the equation: DO2 = CO × arterial oxygen saturation (SpO2) × serum hemoglobin level (Hb) × 1.39 × 10. Calculations done by using index finger SpO2. Subsequently, the DO2 values were adjusted for body surface area (BSA) and weight. We compared DO2 levels within the groups: patients without LVDD and CAD (Group 1), those with only LVDD or CAD (Group 2) and those with both LVDD and CAD (Group 3). <h3>Results:</h3> Among 59 patients included, 56 (94.9%) were female, 44 (74.6%) were diagnosed with limited SSc, and the mean age was 54.2±12.9 years. 21 patients had neither autonomic nor diastolic dysfunction (Group 1), 21 patients had either autonomic or diastolic dysfunction (group 2) and 17 patients had both autonomic and diastolic dysfunction (Group 3). Among patients in group 2,17 had LVDD and 4 had CAD. Group 3 patients had higher proportion of men and diffuse disease and also the mean age of this group was higher, and they had longer disease duration as compared to other groups. Serum hemoglobin levels and Spo2 were similar between the three groups. There was a strong correlation between CO and DO2 (r: 0.898, p&lt; 0.001) (Figure 1). A statistically significant difference in CO and DO2 levels was observed between three groups, with both being lowest in group 3 (p&lt;0.001) (Table 1). <h3>Conclusion:</h3> DO2 was found to be significantly correlated with cardiac functions in SSc patients. SSc patients with both LVDD and CAD had the lowest DO2 levels. A detailed cardiac evaluation is needed in SSc patients to determine different involvement types. <h3>REFERENCES:</h3> [1] Akdogan A, Sari A, Sener YZ, Oksul M, Armagan B, Kilic L, et al. Association between oxygen delivery and digital ulcers in systemic sclerosis. Microvascular research. 2023;145:104449. [2] Bruni C, Ross L. Cardiac involvement in systemic sclerosis: Getting to the heart of the matter. Best practice &amp; research Clinical rheumatology. 2021;35(3):101668. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>