Background/Purpose:

Giant cell arteritis (GCA) is the most common form of primary systemic vasculitis with annual incidence as high as 27 per 100,000 in persons over the age of 50 years. Key issues in management after a diagnosis of GCA include prompt initiation of therapy, prevention and treatment of adverse effects related to treatment, and close monitoring for disease flares. Glucocorticoids are the mainstay of therapy and are used for induction and maintenance of remission. However, there is little consensus on the optimal treatment strategies for GCA. We present treatment patterns in a large real-world population of patients with GCA managed by rheumatologists across the US.

Methods:

The OM1 platform collects, links, and leverages, structured and unstructured data from electronic medical records (EMR) and other sources in an ongoing and continuously updating manner to create a next generation registry-a novel approach to real world evidence. The OM1 GCA Cohort includes data who met our definition of at least two GCA related diagnosis codes [ICD-10: M31.6, M31.5, M31.4; ICD-9:446.7, 446.5] within a 1 year period, treated by rheumatologists, between 2013 and 2016.

Results:

The cohort included 1,567 patients with a mean age of 72 + 10 years, three quarters were Caucasian (78%) and female (76%). Median follow up time was 24 months with a mean of 12 rheumatology ambulatory encounters. Nearly a third of the cohort had a concomitant diagnosis of polymyalgia rheumatica (33%) and 17% had rheumatoid arthritis. A majority of the patients had at least one erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) measurement. Median ESR at baseline was 21mm/hr (IQR: 8, 48) and median CRP was 1mg/L (0.3, 4.0). Only 6% of patients had a documented temporal artery biopsy. Patient reported pain scores were available in 26% of the patients with a median duration of 6 months between first and last assessment. The majority of patients received glucocorticoids (85%), 22% were treated with methotrexate, 8% with hydroxychloroquine, 5% with aspirin, 5% with tocilizumab and 3.5% with azathioprine; 14% were treated with more than one drug concurrently.

Conclusion:

We present findings from a large, representative, cohort of real-world patients seen in routine clinical practice. There are wide variations in patient profile and treatment practices which may reflect the lack of clarity around value of additional steroid-sparing agents to avoid the common glucocorticoid adverse effects and to reduce time to remission.