Incorporating frailty and disease severity into treatment decisions for older patients with ANCA-associated vasculitis.

Abstract

Older patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) are underrepresented in clinical trials, and long-term outcome data in this group are limited. We evaluated treatment approaches and outcomes among hospitalised older patients with AAV. We retrospectively collected clinical and laboratory data on all hospitalised patients aged 75 years or older who commenced remission induction with cyclophosphamide- or rituximab-based regimens for severe AAV between 2014 and 2021. Eighty-four patients were included (median age 79, range 75-93), with a median follow-up of 21 months (IQR 12-44). Choice of induction regimen was influenced by age and frailty: the rituximab-cyclophosphamide combination was more commonly used in younger patients within the cohort, while low-dose rituximab was favoured for the oldest and most frail, including those requiring residential or nursing home care. The distribution of regimens was as follows: rituximab-cyclophosphamide combination (11.9%), cyclophosphamide (26.2%), standard-dose rituximab (39.6%), and low-dose rituximab (22.3%). Serious infection requiring hospital readmission occurred in 27% of patients within the first year, with rates of 37.5%, 23.8%, 25.8%, and 31.6% across the respective treatment groups. One-year mortality was 20% overall (by treatment group: 10%, 23%, 14%, and 26%). Increasing age was associated with higher mortality (HR 4.15, 95% CI 1.62-10.6), but not with serious infection (HR 1.18, 95% CI 0.47-2.93). Considering the enrichment for hospitalised patients with severe disease and advanced age, a mortality rate of 20% at one year that is comparable to less severe and younger cohorts suggests tailoring remission induction strategy according to a holistic assessment of frailty and disease activity may partially mitigate the higher risk of infection and mortality with advancing age.