Hospital Admissions and Mortality in Patients With Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis

Background/objectives: Anti-neutrophil cytoplasmic antibody-associated vasculitis has reported hospital mortality rates ranging between 10% and 20% with inadequate information regarding causes and outcomes of these hospitalizations. Characterization of outcomes in anti-neutrophil cytoplasmic antibody-associated vasculitis can improve patient care and prognostication following hospitalization.

Methods: A medical records review of all hospitalizations between October 1, 2015, and December 31, 2018, of adults with granulomatosis with polyangiitis or microscopic polyangiitis at a single academic medical center was performed. Chart review confirmed diagnoses in patients identified by International Classification of Diseases, Tenth Revision code. Vasculitis activity was determined based on clinical data and treatment during the hospitalization. Differences in outcome measures were analyzed using Fisher exact test, t test, and Wilcoxon signed-rank test.

Results: Of the 127 hospitalizations among 54 patients, active vasculitis was identified in 43 hospitalizations (33.9%). A total of 15 patients with active disease, including 10 patients with a new diagnosis, required intensive care unit (ICU)-level care. Of 84 hospitalizations when vasculitis was inactive, infection was diagnosed in 31 admissions (36.9%), with inactive disease representing 44% of all ICU admissions. Overall mortality was 7% for hospitalized patients and 15% for those admitted to the ICU. An additional 5 patients died within 28 days of discharge, for an overall mortality rate of 17%. All 4 hospital deaths and 3 of 5 postdischarge deaths were in the setting of known infection.

Conclusion: Most hospitalizations and patient deaths were in the context of inactive vasculitis, with infection being the most common cause. Infection and ICU admission were associated with patient death.