Predictors of relapse and treatment outcomes in biopsy-proven giant cell arteritis: a retrospective cohort study

Abstract

Objective: To evaluate characteristics of relapse, relapse rates, treatment and outcomes among patients with biopsy-proven GCA in a large, single-institution cohort.

Methods: We conducted a retrospective review of all patients with biopsy-proven GCA from 1998 to 2013. Demographic, clinical, laboratory and treatment data at presentation and during follow-up were collected. Comparisons by relapse rate were performed using chi-square tests. Prednisone discontinuation by initial oral dose ≤40 and >40 mg/day was compared using Cox models.

Results: The cohort included 286 patients [74% female, mean age at diagnosis 75.0 years (s.d. 7.6), median follow-up 5.1 years). During follow-up, 73 patients did not relapse, 80 patients had one relapse and 133 had two or more relapses. The first relapse occurred during the first year in 50% of patients, by 2 years in 68% and by 5 years in 79%. More patients with established hypertension (P = 0.007) and diabetes (P = 0.039) at GCA diagnosis were in the high relapse rate group ( ≥ 0.5 relapses/year) and more females were in the low or high relapse groups than in the no relapse group (P = 0.034). Patients receiving an initial oral prednisone dose >40 mg/day were able to reach a dose of <5 mg/day [hazard ratio (HR) 1.46 (95% CI 1.09, 1.96)] and discontinue prednisone [HR 1.56 (95% CI 1.09, 2.23)] sooner than patients receiving ≤40 mg/day without an increase in observed glucocorticoid-associated adverse events.

Conclusion: Females and patients with hypertension or diabetes at GCA diagnosis have more relapses during follow-up. Patients treated with an initial oral prednisone dose >40 mg/day achieved earlier prednisone discontinuation.

Keywords: adverse events; cohort; diabetes; giant cell arteritis; glucocorticoids; hypertension; relapse; retrospective.

Fig. 1

Cumulative incidence (%) for patients achieving daily oral prednisone dose <10 mg/day (dotted line), <5 mg/day (dashed line) or discontinuation (solid line)

Fig. 2

Cumulative incidence (%) for patients achieving prednisone <5 mg/day or discontinuation based on initial oral dose Percentage of patients achieving prednisone (PDN) dose (A) <5 mg/day or (B) discontinuation in patients treated with initial oral PDN dose >40 mg/day (dotted line) compared with ≤40 mg/day (solid line).