Structural and functional outcomes of a therapeutic strategy targeting low disease activity in patients with elderly-onset rheumatoid arthritis: a prospective cohort study (CRANE)

Objective. The aim of this study was to evaluate structural damage and physical disability in patients with elderly-onset RA (EORA) who were treated in clinical practice with a therapeutic strategy targeting low disease activity (LDA). Methods. Data from 151 MTX-naive patients (mean age 74.9 years) with EORA from a prospective, monocentric registry were analysed. Treatment was adjusted every 3 months targeting LDA [28-joint DAS using ESR (DAS28-ESR) < 3.2]. Treatment was initiated with non-biologic DMARDs (nbDMARDs), followed by TNF inhibitors (TNFis) or tocilizumab. The primary outcome was change from week 0 to week 52 in the modified total Sharp score (Delta mTSS). Secondary outcomes were derived from the HAQ Disability Index (HAQ-DI) and DAS28 at week 52. Predictors of clinically relevant radiographic progression [CRRP; Delta mTSS/year more than the smallest detectable change (2.1 points)] were examined using multivariate logistic regression models. Results. Adherence to the treat-to-target strategy was observed in 83.4% of the 151 patients at week 24 and in 75.5% at week 52. At week 52, 67.6% of the patients were receiving a nbDMARD alone, 31.0% a TNFi with or without MTX and 1.4% tocilizumab. At week 52, structural remission (Delta mTSS/yr a parts per thousand currency sign0.5) was achieved in 49.7% of the patients, functional remission (HAQ-DI a parts per thousand currency sign0.5) in 63.4% and LDA in 51.0%. Clinical responses at weeks 12 and 24 were significant independent predictors of CRRP. Cumulative disease activity during the first 12 weeks predicted CRRP with a C-statistic of 0.888. Conclusion. Achieving structural remission, functional remission and LDA in clinical practice in EORA patients are realistic goals. Our results indicate significant benefits for a therapeutic strategy targeting LDA for EORA patients in clinical practice.