Age at Disease Onset Associated With Type of Clinical Manifestations in Patients With GCA

Among older adults with giant cell arteritis (GCA), age at disease onset has a considerable effect on clinical manifestations, risk for ischemic sequelae, adverse events, and treatment approaches, according to study findings published in Annals of the Rheumatic Diseases.

Patients with a confirmed GCA diagnosis between January 1988 and November 2020 were included in the analysis. Patients were diagnosed and followed-up with at 18 referral centers in the Italian Society of Rheumatology Vasculitis Study Group. Those who had at least 6 months follow-up were included in the study.

The primary study endpoint was an evaluation of the association of age at disease onset with the number of relapses.

Secondary endpoints included the following:

• Association of age with time to first relapse
• Association of age at disease onset with time to reach a low glucocorticoid dose (≤5 mg/day)
• Association of age at disease onset with time to initiate an additional immunosuppressants and the number of these medications used
• Association of age at disease onset with disease-related outcomes at
  12 and 60 months
• Association of age at disease onset with treatment-related outcomes at
  12 and 60 months
• Association of age at disease onset with overall survival

A total of 1004 patients with GCA were included in the study. Overall, 711 participants were women. The mean patient age was 72.1±8.4 years. The median duration of follow-up was 49 months.

All participants were grouped according to their age at diagnosis (≤64 years [n=195]; 65-79 years [n=617]; and ≥80 years [n=192]).

Results of the study showed that patients aged 80 years and older experienced significantly more cranial symptoms and ischemic complications. In addition, permanent visual loss was reported significantly more often in the oldest age group, with 36.98% of individuals aged 80 years and older presenting with blindness compared with 18.21% of those aged between 65 and 79 years and 6.19% of those aged 64 years and younger (P <.0001).

Relapses were reported in 47% of participants over a 4.1-year median follow-up, which resulted in an overall rate of 15 relapses per 100 person-years (95% CI, 14-16 per 100 person-years). Age did not affect time to first relapse or the number of relapses.

Incidence of relapses among those aged 64 years and younger, 65 to 79 years, and 80 years and older were 14, 16, and 12 relapses per 100 person-years, respectively.

Further, the occurrence of large-vessel GCA (LV-GCA) was reported most often in the youngest age group (65% of participants). Older age was negatively associated with the number of adjunctive immunosuppressants used. Participants who were older than 65 years had a 2- to 3-fold elevated risk for aortic dissection/aneurysm up to 60 months of follow-up.

A total of 58 deaths were reported, resulting in an overall mortality rate of 5.8%. Mortality rates were 0.08 per 100 person-years (95% CI, 0.012-0.6 per 100 person-years) among those aged 64 years and younger; 1.26 per 100 person-years (95% CI, 0.92-1.72 per 100 person-years) among those aged between 65 and 79 years; and 1.94 per 100 person-years (95% CI, 1.21-3.13 per 100 person-years) among those aged 80 years and older.

Study limitations included its observational design and the potential bias associated with more severe, complicated cases being referred to the centers in Italy. In addition, variations existed at the centers regarding treatment selections and the use of imaging to detect LV-GCA.

“[O]ur study demonstrates that, given the higher risk for severe [ischemic] manifestations, aortic complications, serious infections, death, and potential undertreatment, [older] patients with GCA represent a unique and challenging subgroup of patients that deserves further dedicated research to [optimize] their management and improve prognosis,” the researchers concluded.