Subclinical atherosclerosis in systemic sclerosis and rheumatoid arthritis: a comparative matched-cohort study

Systemic autoimmune inflammatory disorders confer a higher risk of cardiovascular (CV) disease leading to increased morbidity and mortality and reduced life expectancy compared to the general population. CV risk in systemic sclerosis (SSc) has not been studied extensively but surrogate markers of atherosclerosis namely carotid intima media thickness (cIMT) and pulse wave velocity (PWV) are impaired in some but not all studies in SSc patients. The aim of this study was to investigate the prevalence of subclinical atherosclerosis assessed by cIMT and PWV between two well-characterized SSc and Rheumatoid Arthritis (RA) cohorts. Consecutive SSc patients attending the Scleroderma Clinic were compared with RA patients recruited in the Dudley Rheumatoid Arthritis Co-morbidity Cohort (DRACCO), a prospective study examining CV burden in RA. Augmentation Index (Aix75) and cIMT were measured in all participants. Propensity score matching was utilised to select patients from the two cohorts with similar demographic characteristics, CV risk factors and inflammatory load. Unpaired analysis was performed using unpaired t test for continuous variables and χ² test for dichotomous variables. Statistical analysis was repeated using paired t test for continuous normal variables and McNemar's test for dichotomous variables. Fifty five age- and sex-matched SSc and RA patients were included in the analysis. No difference was demonstrated between SSc and RA subjects regarding cIMT (0.66 mm vs 0.63 mm, respectively) and Aix75% measurements (33.4 vs 31.7, respectively) neither in paired (p = 0.623 for cIMT and p = 0.204 for Aix%) nor in unpaired t test analysis (p = 0.137 for cIMT and p = 0.397 for AIx%). The results of this comparative study show that subclinical atherosclerosis is comparable between SSc and RA, a systemic disease with well-defined high atherosclerotic burden. Such findings underscore the importance of CV risk management in SSc in parallel with other disease-related manifestations.