0375: The Presence of Heel Enthesitis on Physical Exploration Is Associated with Poorer Outcomes After 2 Years of Follow-up in Patients with Radiographic Axial Spondyloarthritis

Clementina Lopez-Medina¹, Maria Angeles Puche Larrubia², lourdes Ladehesa-Pineda³, Raquel Granados⁴, Pilar Font⁵ and Eduardo Collantes⁵, ¹Reina Sofia University Hospital, Rheumatology Department, Jaén, Spain, ²Reina Sofia University Hospital/Rheumatology Department/Maimonides Institute for Biomedical Research (IMIBIC), Granada, Spain, ³Reina Sofia University Hospital/Rheumatology Department/Maimonides Institute for Biomedical Research (IMIBIC), Cordoba, Spain, ⁴Reina Sofia University Hospital/Rheumatology Department/Maimonides Institute for Biomedical Research (IMIBIC), Córdoba, Spain, ⁵IMIBIC/University of Cordoba/Reina Sofia Hospital, Cordoba, Spain

Background/Purpose: Enthesitis represents one of the most important peripheral musculoskeletal manifestation in patients with axial Spondyloarthritis (axSpA). The prevalence and the burden of the disease associated with this symptom have been widely studied in axSpA and Psoriatic Arthritis (PsA). However, studies evaluating specifically the heel enthesitis and its impact over time are scarce. The objectives of this study were: a) to evaluate the prevalence of patients with heel enthesitis during physical exploration in patients with radiographic axSpA (r-axSpA); b) to evaluate the association of heel enthesitis with higher Patient Reported Outcomes (PROs); c) to assess the impact of the heel enthesitis on the outcome measures after two years of follow-up in these patients.

Methods: Observational and prospective study during 2 years of follow-up that included patients with r-axSpA from the REGISPONSER-AS study (Spanish Rheumatology Spondyloarthritis Registry). The patients were divided into two groups according to the presence on heel enthesitis on physical exploration during the study visit. The PROs evaluated were the Global VAS, BASDAI, ASDAS, BASFI and the mental and physical components from the SF12 questionnaire. Linear regression models were performed using the PROs as the dependent variable and the presence of heel enthesitis as the explanatory variable, adjusting for bDMARDs intake and age. The impact of the heel enthesitis on PROs over two years of follow-up was evaluated using mixed models for repeated measures adjusting for confounders. Finally, the achievement of ASDAS Low Disease Activity (ASDAS-LDA) and ASDAS Inactive Disease (ASDAS-ID) after 2 years of follow-up between the two groups were evaluated.

Results: 749 patients were included (mean age 48.4 years; 75.3% men). 46 (6.1%) patients suffered from heel enthesitis on the study visit. Patients with heel enthesitis showed an increase (β coefficient, 95%CI) in Global VAS (1.32, 0.52-2.12), BASDAI (1.49, 0.81-2.18), ASDAS (0.45, 0.12-0.77) and BASFI (9.54, 1.78-17.30) compared with patients without heel enthesitis after adjusting for confounders. The impact of the number of comorbidities on the PROs after two years of follow-up is shown in Table 1. Patients with heel enthesitis showed higher scores during the two years of follow-up in Global VAS, BASDAI, ASDAS and BASFI. In addition, the percentage of patients who achieved ASDAS-LDA after 2 years of follow up was lower in patients with heel enthesitis (15.9% vs. 31.5%, p=0.030) in comparison with patients without enthesitis. No differences were found regarding ASDAS-ID.

Conclusion: In patients with r-axSpA, the presence of heel enthesitis on physical exploration was associated with poorer scores on the outcome measures after two years of follow-up, in comparison with patients without heel enthesitis. The achievement of a low disease activity is less likely in patients with this manifestation.

Disclosures: C. Lopez-Medina, None; M. Puche Larrubia, None; l. Ladehesa-Pineda, None; R. Granados, None; P. Font, None; E. Collantes, None.