OP0150 Ultrasound power doppler activity predicts clinical joint swelling in early rheumatoid arthritis patients: secondary analyses from the arctic trial
Authors: L.B Nordberg, S. Lillegraven, A.-B. Aga, J. Sexton, E. Lie, H.B. Hammer, I.C. Olsen, T. Uhlig, D. van der Heijde, T.K. Kvien, E.A. Haavardsholm
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Ultrasound is increasingly applied in the management of rheumatoid arthritis (RA). It is important to detect synovitis early to prevent future joint damage and disability. It is not known whether subclinical ultrasound inflammation in a joint precedes clinical joint swelling. <h3>Objectives</h3> We aimed to investigate whether ultrasound power Doppler (PD) activity in a joint is associated with subsequent clinical joint swelling in early RA patients. <h3>Methods</h3> In the treat-to-target ARCTIC trial, DMARD naïve early RA patients were randomised to follow-up with or without ultrasound, with the same treatment algorithm applied in both arms. Patients were assessed by 44 swollen joint count at all visits (13 visits over two years). Ultrasound examinations were performed using a validated 0–3 semi-quantitative scoring system.<sup>1</sup> with assessments at all visits in the ultrasound arm and at baseline, 12 and 24 months in the conventional arm. We calculated the risk of next-visit clinical joint swelling according to ultrasound inflammation status in clinically non-swollen joints at the preceding visit. We estimated the odds ratio of a joint being swollen at next visit in joints with different PD activity (PD score: 1, 2 or 3), compared to non-swollen joints with no PD activity (PD score=0). These calculations were performed in a logistic mixed-effects model with random intercepts for patient and joint in order to account for within-patient and -joint dependencies, and were adjusted for age, gender, ACPA status, DMARD treatment and strategy arm. Joints injected with corticosteroids were excluded. Data from the two strategy arms were pooled and analysed together, as clinical and radiographic outcomes were similar in the two arms after two years.<sup>2</sup> <h3>Results</h3> 230 patients were included (118 in the ultrasound strategy arm, 112 in the conventional strategy arm). Mean (SD) age was 51.4 (13.7) years, 61% were female and mean baseline DAS was 3.46 (1.17). The risk of clinical joint swelling at the next visit increased with grade of PD activity (table 1). PD=Power Doppler. Odds ratios are adjusted for within-patient and within-joint dependencies, gender, age, DMARD treatment, ACPA status and strategy arm. <h3>Conclusions</h3> We found PD activity in non-swollen joints to be strongly associated with development of clinical joint swelling at the next visit, and the risk increased with higher power Doppler activity. This study supports the use of ultrasound as a tool to detect joints at risk for developing clinical synovitis. <h3>References</h3> [1] Hammer HB, et al. <i>ARD</i>2011. [2] Haavardsholm EA, et al. BMJ2016. <h3>Disclosure of Interest</h3> L. Nordberg: None declared, S. Lillegraven: None declared, A.-B. Aga: None declared, J. Sexton: None declared, E. Lie: None declared, H. Hammer: None declared, I. Olsen: None declared, T. Uhlig: None declared, D. van der Heijde: None declared, T. Kvien: None declared, E. Haavardsholm Grant/research support from: Pfizer, UCB, Roche, MSD, and AbbVie