Effect of treat-to-target strategies on bone erosion progression in early rheumatoid arthritis: An HR-pQCT study

Objectives: To investigate the efficacy of two tight-control treatment strategies aimed at simplified disease activity score [SDAI] remission (SDAI ≤ 3.3) compared to DAS28 remission (DAS28 < 2.6) on progression of bone erosions in early rheumatoid arthritis (ERA) patients using high-resolution peripheral quantitative computed tomography (HR-pQCT). Methods: This was an open-label study in which 80 early RA patients were randomized to receive 1-year of tight-control treatment. Group 1 (n = 37) aimed at SDAI ≤ 3.3 and group 2 (n = 43) aimed at DAS28-CRP < 2.6. The number and size of bone erosions, as well as the bone mineral density (BMD) surrounding bone erosion at the second metacarpophalangeal joint (MCP2), were measured at baseline and 12 months. Results: After 12 months, images were analyzed in 63 patients. Changes in clinical parameters, number and size of bone erosions as well as the BMD surrounding bone erosion between the two treatment groups were similar. Therefore, a post-hoc analysis including all 63 patients was performed to elucidate the independent predictors of erosion progression and repair. Multivariate analysis revealed that not achieving sustained SDAI remission at month 6, 9 and 12 (p = 0.034) and rheumatoid factor >16U (p = 0.021) were independent predictors associated with an increase in erosion volume. Logistic regression analysis showed that achieving sustained SDAI remission (p = 0.043) was associated with partial erosion repair. Conclusions: Although more stringent treatment target did not notably affect clinical treatment outcome and erosion progression at 1 year, achieving sustained SDAI remission was found to be associated with partial erosion repair.