Background/Purpose:

Patients with rheumatoid arthritis (RA) should achieve remission rapidly to avoid irreversible joint sequela. Studies have shown that patients with apparent clinical remission have positive power Doppler on ultrasound examination, suggestive of ongoing inflammatory disease activity. The purpose of this study was to retrospectively determine the flare rate at 12 months in patients with RA, who had a diagnosis of clinical remission and ultrasound remission compared with patients who had only a diagnosis of clinical remission.

Methods:

In this retrospective study, we used medical charts to identify patients with RA and a diagnosis of remission made between January 2012 and January 2017. Patient demographics and information on treatment and outcome were retrieved from the medical charts (Table 1). Patients were defined to be in remission when they had ≤1 swollen joint and diagnosis of remission by clinician. We then separated patients in 2 groups based on whether the patient had undergone ultrasound. We retrospectively compared the flare rate at 12 months, in patients who had a clinical diagnosis of remission and an ultrasound diagnosis of remission versus patients who had a clinical diagnosis of remission. Flare during follow-up was defined by clinician diagnosis and >1 swollen joint and/or need to change the medication regimen for RA. We also calculated the time between diagnosis of remission and flare.

Results:

A total of 121 patients were included, 108 females and 13 males. Clinical and ultrasound remission was diagnosed in 34 patients while 87 patients were diagnosed with clinical remission. Baseline characteristics in 2 groups were similar, except for longer duration of disease, more biologic therapy received in the past and more smokers in the group without ultrasound (Table 1). Of the patients who had a diagnosis of remission with ultrasound, 7 (20.6%) flared during follow-up compared to 37 (42.5%) who did not have an ultrasound.  After accounting for smoking as a covariate, this difference in flare rates was statistically significant (p=0.047). The time to first flare appeared longer in the ultrasound group compared to the clinical group, although this difference was not significant (p=0.105).

Conclusion:

This retrospective study demonstrated a smaller incidence of RA flare at 12 months in patients who had a clinical diagnosis of remission with ultrasound compared to patients who had a diagnosis of remission without ultrasound. Further prospective studies comparing the clinical approach with combined approach are needed to identify the real value of ultrasound for RA remission diagnosis