Background/Purpose: With implementation of tight control strategies and defined treatment targets in rheumatoid arthritis (RA) care, a majority of early RA patients may reach remission and traditional predictors of joint damage might no longer be present. The aim of our study was to identify baseline parameters predictive of 2-year radiographic progression in an early RA population treated by a semi-personalized treat-to-target strategy.

Methods: DMARD naive RA patients with <2 years from first patient reported swollen joint, who fulfilled the 2010 ACR/EULAR criteria, were included in the ARCTIC study. Patients were followed for 24 months with treatment according to an aggressive algorithm targeting clinical remission (DAS <1.6 and SJC44=0), and in half the patients an additional target was imaging remission (absence of ultrasound PD signal). Patients with risk factors for progressive joint destruction (ACPA or RF positive with baseline erosions, or MRI bone marrow edema) could be escalated more rapidly from MTX monotherapy to biologics. Radiographs were scored by two readers using the van der Heijde-Sharp score (vdHSs), with cut-off 1 unit or more change/year to be classified as progression. Potential baseline predictors were analyzed for collinearity, and remaining variables assessed by univariate logistic regression. Variables with univariate p<0.25 were included in the multivariate model building, and p<0.05 was required to remain in the model.

Results: Mean [SD] disease duration for the 222 patients was 7.2 [5.4] months, and mean DAS based on 44 joints was 3.5 [1.2]. 72% were RF and 82% ACPA positive. 41% had radiographic progression at 24 months, while DAS remission was reached by 68%. In 16% treatment was escalated more rapidly due to baseline risk factors. In univariate models, gender, age, smoking, RF, tender joints, 44 SJC, ESR, total GS-score, total PD-score and vdHSs at baseline had p<0.25, while BMI, disease duration<3months, ACPA and patient global had p>0.25. In the multivariate model, RF positivity (OR 2.27, p=0.022), total vdHSs (OR 1.08, p=0.017) and ultrasound GS score (OR 1.03 per unit, p=0.019) were independent baseline predictors of radiographic progression at 24 months (table). Ultrasound PD was not an independent predictor in secondary models built without GS or in separate models for the two strategy arms, neither as a continuous nor dichotomized variable according to the mean (9.8) and median (7) baseline score.

Conclusion: RF positivity, radiographic joint damage and ultrasound gray-scale score were independent baseline predictors of joint damage in early RA patients treated according to an aggressive treatment regimen aiming for remission. This indicates that further individualization of treatment based on risk factors might be needed to optimize disease outcomes, also in treat-to-target strategies.