Outcome of Takayasu arteritis with inactive disease at diagnosis: The extent of vascular involvement as a predictor of activation

Abstract

Objective. Some patients with Takayasu arteritis (TA) have inactive disease at the time of diagnosis. The objective of our study was to investigate the clinical outcomes and factors that predict disease activation in patients with clinically inactive TA. Methods. The medical records of patients diagnosed with TA between 1990 and 2012 were reviewed. At the time of diagnosis, patients were identified as having inactive disease according to the National Institutes of Health definition. Patients who went on to develop active disease during followup were classified as the "activation group". The pattern of vascular involvement was classified according to the International Conference on TA, 1994. Results. A total of 59 patients with TA were classified as having inactive disease at the time of diagnosis. During the followup, 13 (22.0%) of these experienced TA activation (median followup, 37.0 mos; activation group). The remaining 46 (78.0%) did not experience disease activation (stable group). Renovascular hypertension was more common in the activation group than in the stable group (5/13, 38.5% vs 4/46, 8.7%, p = 0.019). Further, type V, which is the most extensive, was more common in the activation group (12/13, 92.3%) than in the stable group (18/46, 39.1%, p = 0.008). Multivariate analysis identified type V disease (OR 10.969, 95% CI 1.144-105.182, p = 0.038) as being significantly associated with an increased risk of disease activation. Conclusion. Substantial portions of patients with clinically inactive TA at the time of diagnosis experienced disease activation during followup. Type V disease may be an important predictive factor for disease activation in patients with clinically inactive TA.