Background/Purpose: It has been debated whether treatment outcomes in early RA would be improved by targeting imaging remission, assessed by ultrasound or MRI, in addition to clinical remission. The primary analyses of the ARCTIC and TaSER trials (Haavardsholm et al. BMJ 2016; Dale et al. ARD 2016) did not show a beneficial effect of adding structured ultrasound assessment to a treat-to-target strategy. However, both studies reported a trend toward less radiographic progression in the ultrasound arm. We aimed to investigate whether an ultrasound-guided strategy would lead to reduced MRI inflammation or structural damage compared to a conventional treat-to-target strategy.

Methods: The ARCTIC trial included 230 DMARD-naïve early RA patients aged 18-75, randomized 1:1 to an ultrasound strategy targeting DAS < 1.6, no swollen joints and no power-Doppler signal in any joint, or a conventional strategy targeting DAS < 1.6 and no swollen joints. All patients were treated by the same DMARD escalation algorithm starting with MTX, then combination therapy MTX/SSZ/HCQ, then biologic DMARD. In the ultrasound arm, treatment was stepped up if indicated by the ultrasound score, overruling the DAS and swollen joint count. MRI of dominant hand was performed at 6 times and scored in chronological order by a blinded reader. MRI acquisitions and scoring were done according to the OMERACT RA MRI Scoring System (Østergaard et al. J Rheum 2017). 218 patients (ultrasound n=116, conventional n=102) had MRI at baseline and ≥ 1 follow-up visit, and were analyzed. A combined inflammation score was computed by normalized summation of the synovitis, tenosynovitis and bone marrow edema scores, and a combined damage score by normalized summation of the erosion and joint space narrowing scores (Sundin et al. J Rheum 2019). Mean change from baseline to each follow-up was estimated by a linear mixed model adjusted for baseline score, age, gender, center and anti-CCP status. The proportion of patients in each treatment arm with MRI erosive progression after 2 years was calculated, using the smallest detectable change (0.61) as cut-off.

Results: Demographic composition was comparable to the ARCTIC primary sample. There were no statistically significant baseline differences between the arms in either of the combined MRI scores. The mean combined MRI inflammation score decreased during the first year (1-year change in ultrasound arm −64.2 (−71.3; −57.1), conventional arm −59.4 (−66.9; −51.9) p=0.34), and maintained at the same level throughout the 2^nd year. There was no significant difference in change from baseline between the study arms at any time (figure 1a). The mean combined MRI damage score showed a small increase over time, without any significant difference between study arms (figure 1b). In the ultrasound arm 39% of patients had MRI erosive progression vs. 33% in the conventional arm, RR: 1.16 (95% CI 0.81; 1.66), p=0.40.

Conclusion: Incorporating ultrasound information in treatment decisions did not lead to reduced MRI inflammation or less structural damage, compared to a conventional treatment strategy. The findings support that systematic use of ultrasound does not provide benefit in treat-to-target follow-up of patients with early RA.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/ultrasound-versus-conventional-treat-to-target-strategies-in-early-rheumatoid-arthritis-magnetic-resonance-imaging-outcome-data-from-a-2-year-randomized-controlled-strategy-trial/