6-Minute Walking Test in Rheumatoid Arthritis: Clinical Associations and Prognostic Implications

Background The clinical associations and prognostic implications of the 6-minute walk test (6MWT) distance in patients with rheumatoid arthritis (RA) is yet to be explored. Aims To identify the clinical features and prognostic implications associated with the 6MWT in patients with RA. Methods Cohort study including 387 RA patients who underwent 6MWT. Regression models (linear and logistic) were built to identify independent predictors of shorter 6MWT distance. Cox proportional models were used to study the association of 6MWT distance with cardiovascular outcomes. Results Patients were subdivided according to 6MWT tertiles: 126 patients walked > 405m, 129 walked 345-405m, and 132 walked 55 year), elevated waist circumference, NT-pro BNP > 125pg/mL, anemia, C-reactive protein ≥ 3mg/dL, and troponin T ≥ 14pg/mL were independent predictors of walking shorter distances. Patients walking less than 345m had higher risk of a subsequent cardiovascular hospitalisation or cardiovascular death compared with patients walking 345m or more (adjusted HR: 2.98, 95%CI: 1.37–6.51, p = 0.006). Conclusions Older age, abdominal obesity, anemia, cardiac dysfunction, and inflammation were associated with walking shorter distances in patients with RA. Walking less than 345m in the 6MWT was associated with a poor cardiovascular prognosis. The 6MWT is simple, reproducible and inexpensive, easily performed in routine practice, and provides important information regarding the patients´ status and outcomes, enabling the monitorization of the therapeutic optimization of the various domains of the RA.