ARCTIC Study Shows No Benefit to Ultrasound Remission in RA Save

The goal in rheumatoid arthritis (RA) treatment is remission. But what level or method of remission is best? Using clinical parameters, there are numerous definitions of remission to choose from (ACR boolean, CDAI, SDAI, etc.) and not all measures perform equally when applied to the same patients.  
The issue becomes more confused if you consider studies of patients in remission by clinical parameters, but then find evidence of occult synovial inflammation by either MRI or ultrasound.  

Researchers from Norway studied RA patients to determine if an ultrasound-guided T2T (treat-to-target) strategy would yield better outcomes over time.

A multicenter, open-label, randomized clinical trial included 238 RA patients and analyzed 230 RA patients who were DMARD-naive at entry.  An ultrasound tight control strategy targeting clinical and imaging remission was used in 122 patients, and 116 patients were randomised to a conventional tight control strategy targeting clinical remission (DAS28 2.6). Patients in both arms were treated according to the same disease modifying anti-rheumatic drug escalation strategy, with 13 visits over two years.

The primary endpoint was percentage of patients in clinical remission (defined as no swollen joints, no X-ray progression) after 16 and 24 months.  

Equal outcomes were observed with 22% of the ultrasound tight control, and 19% of the clinical tight control arm achieved the primary endpoint.  All other secondary endpoints and safety measure (disease activity, physical function, and joint damage) saw similar outcomes between the two groups.

The ARCTIC study shows that finer specificity of "remission" using US or imaging does not enhance the clinical outcomes appreciably in RA over a 2-year period.  The structural and clinical consequences may differ with even longer follow-up or with other more sensitive measures of remission, but those results remain to be seen.