Clinical associations and prognostic implications of 6-minute walk test in rheumatoid arthritis

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. To identify the clinical features and prognostic implications associated with the 6MWT in patients with RA. 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. Patients were subdivided according to 6MWT tertiles: 126 patients walked > 405 m, 129 walked 345-405 m, and 132 walked < 345 m. Older age (> 55 years), elevated waist circumference, NT-pro BNP > 125 pg/mL, anemia, C-reactive protein ≥ 3 mg/dL, and troponin T ≥ 14 pg/mL were independent predictors of walking shorter distances. Patients walking less than 345 m had higher risk of a subsequent cardiovascular hospitalization or cardiovascular death compared with patients walking 345 m or more (adjusted HR: 2.98, 95%CI: 1.37-6.51, p = 0.006). Older age, abdominal obesity, anemia, cardiac dysfunction, and inflammation were associated with walking shorter distances in patients with RA. Walking less than 345 m 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.