OP01 MRI is of utility in the evaluation of disease activity in axial Spondyloarthritis- data from a tertiary rheumatology centre

Abstract Background Assessing disease activity in axial spondyloarthritis (axSpA) is challenging, with heavy reliance on patient reported outcome measures. These measures are subjective and can be influenced by non-inflammatory causes of symptoms, potentially resulting in inappropriate changes to therapy. Despite its unanimous use in the diagnosis of axSpA, the most recent EULAR/ASAS guidelines do not support the use of MRI to assess disease activity due to the lack of evidence and cost implications. However, it is often a pragmatic approach taken in clinical practice. Aims To assess current usage of MRI to assess disease activity in axSpA at Leeds Teaching Hospitals NHS Trust (LTHT), particularly in patients experiencing treatment non-response and how findings influence treatment decision making at the bedside. Methods As part of a larger service evaluations, MRIs of the whole spine and SIJ requested at LTHT between May 2020 and December 2023 to assess disease activity in patients with previously diagnosed axSpA nr-axSpA, r-axSpA or axial psoriatic spondyloarthritis [axPsA]) were identified. Clinical data was extracted from electronic health records and clinic letters. Results In total 237 MRI scans were performed on 231 patients. The average age was 47, 131 (55.3%) were male and 145 (60.3%) were HLA-B27 positive. 109 had a diagnosis of radiographic axSpA, 95 non-radiographic and 27 axial PsA. 167 were on a b/ts-dmard at time of MRI. Overall, 116 (48.9%) had inflammation in spine or SIJ and 137 (57.8%) had non-axSpA related pathology on MRI. Patients with active inflammation were more likely to have their treatment switched or escalated than those without (48% vs 18%). 12 patients were referred to spinal surgical services, 6 to the pain team and 1 to oncology services, based on the results of the MRI scan. Conclusions Findings on MRI to assess disease activity influences treatment decisions in a large proportion of patients. Further research into the utility and health economics of MRI to assess disease activity in routine clinical practice, particularly in those experiencing treatment non-response is urgently required.