Remission has become an achievable goal for a large proportion of patients with rheumatoid arthritis (RA).1 In 2022, ACR and EULAR proposed a new version of their Boolean remission criteria, allowing patients to achieve remission with a higher level of patient global assessment (PGA). In the updated version, the threshold for PGA (0–10 cm) is 2 (Boolean 2.0), compared with the original threshold of 1 (Boolean 1.0).2 3 We aimed to investigate subclinical inflammation according to ultrasound and MRI, as well as radiographic progression, in patients with early RA fulfilling ACR/EULAR Boolean 2011 and 2022 remission criteria.

The ARCTIC trial was a multicentre, open-label, randomised controlled strategy trial conducted in Norway. Patients were 18–75 years, fulfilled the 2010 ACR/EULAR classification criteria for RA, disease-modifying anti-rheumatic drug (DMARD) naïve and had an indication for DMARD therapy when included in the trial.4

A structured ultrasound grey scale and power Doppler assessment of 32 joints, and evaluation of MRI synovitis, tenosynovitis, bone marrow oedema and MRI total inflammation score of dominant wrist and hand were performed at baseline, 12 and 24 months. At 12 and 24 months, patients were categorised as being in Boolean 1.0 remission or remission according to only Boolean 2.0 (ie, in Boolean 2.0 but not 1.0 remission). Linear mixed effect regression models were fit to ultrasound and MRI inflammation data, treating time as a categorical effect and with an indicator for whether a patient was in Boolean 1.0 or only 2.0 remission at the visit. Sensitivity analyses were done with log transformation of the MRI and ultrasound …