AB1188 THE FUNCTIONAL CORRELATIONS OF ELECTROCARDIOGRAM CHANGES IN SYSTEMIC SCLEROSIS PATIENTS
Authors: F. Negoi, A. M. Cojocaru, A. Dima, I. Catanoiu, A. A. Rakoczy, N. D. Popescu, M. Parvu
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Systemic Sclerosis (SSc) is a rare autoimmune disease characterized by vascular abnormalities and diffuse fibrosis including patchy fibrosis of the myocardium and subsequent conduction abnormalities. As much as 27% of SSc deaths are due to cardiac impairment. The electrocardiogram (ECG) remains the most used screening tool for cardiac electrical activity [1]. <h3>Objectives:</h3> To evaluate the prevalence and functional associations of ECG abnormalities in SSc patients. <h3>Methods:</h3> We performed a prospective cross-sectional analysis of patients fulfilling the 2013 American College of Rheumatology/ European League Against Rheumatism (ACR/EULAR) SSc classification criteria who were hospitalized in our Rheumatology Department from November 2022 to December 2023. A wide range of variables were collected, namely patients' demographic data, personal and family history, disease history, comorbidities and treatment, blood tests which included the lipid profile, cardiac enzymes, thyroid markers, and complete antibody profile. Cardiac involvement was also evaluated with ECG at rest, performed at inclusion and by echocardiography (echo). <h3>Results:</h3> 73 patients, 7 (9.6%) males and 66 (90.4%) females, with mean±SD age at inclusion of 59.3±11.7 years were included, 32 (44%) with diffuse cutaneous form, 40 (55%) with limited cutaneous form and 1 (1%) with sine scleroderma form. The descriptive ECG and echo parameters are presented in Table 1. The Intraventricular conduction disturbances (IVCD) were most frequently identified in our lot (n-38, 52%) with the highest prevalence for the right bundle branch block (RBBB). The IVCD was associated with the QRS complex width (r-379, p=0.023), higher PAPs level (34.4±12.2 vs 28.8±7.5, p=0.007), and also with the Rodnan results for the hand-fingers (2 (1;3) vs 0.5(0;2), p=0.028). Further, the RBBB was more frequent in patients with high cholesterol levels (148.7±53 vs 182.2±49.6 p=0,046). The N-terminal prohormones of brain natriuretic peptides (NT-proBNP) values were related with prolonged PR interval (p=0.006), laboratory parameters such as cholesterol fractions, creatinine, (147.2 (75.4;173.9) vs 175.7 (149.9;217.1), p=0.012, 0.87 (0.74;1.78) vs 0.71 (0.62;0.81), p=0.025). Furthermore, positive associations were identified for Rodnan total and hand score and azathioprine posology (14 (4.5;25.5) vs 6 (4;11), p=0.043, 2 (0;3) vs 0 (0;3), p=0.026, p r-624, p=0.013). Regarding the autoimmunity profile, there was no significant association with the criteria SSc antibodies and atrioventricular conduction disturbances (AVCD), even if the anti-SCL-70 antibodies were associated with QT interval duration (0.36±0.03 vs 0.38±0.03, p=0.039). However, the patients with anti-Ro antibodies (113.7±0.83 vs 18.19±4.6, p&lt;0,001) were at more risk of developing AVCD. Regarding the immunosuppressant treatment, we found an interesting association between Azathioprine treatment and higher prevalence of IVCD and AVCD (19/59 (32.2%) vs 4/5 (80%), p=0,003 and 18/34 (53%) vs 5/30 (16.7), p=0,032). <h3>Conclusion:</h3> Standard ECG is a useful screening tool to identify cardiac involvement in patients with SSc. RBBB was identified most frequently on our patients' ECG at inclusion. Laboratory tests such as cholesterol fraction, positive NT-proBNP, presence of anti-Ro and anti-SCL70 antibodies present significant correlations with ECG changes suggestive for conduction disturbances. Azathioprine treatment associated higher occurrence of conduction disorders, thus further analyzes of possible confounders should be considered. <h3>REFERENCES:</h3> [1] M. Vrancianu CA et al. "Arrhythmias and Conduction Disturbances in Patients with Systemic Sclerosis-A Systematic Literature Review.," <i>Int J Mol Sci. 2022 Oct 26;23(21):12963. doi: 10.3390/ijms232112963. PMID: 36361752; PMCID: PMC9658897.</i> <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>