Background: Primary systemic vasculitis are a heterogeneous group of diseases characterized by inflammatory involvement of the blood vessel wall leading to organ damage. Taking into account the severity of the complications of this disease, it is interesting to determine which are those that required hospitalization and to evaluate the factors associated with mortality in these patients.

Objectives: To estimate the frequency of mortality in patients diagnosed with primary vasculitis who required hospitalization and to evaluate its possible predictors.

Methods: We conducted a retrospective, observational study that included patients older than 16 years with a diagnosis of primary vasculitis (ACR 1990 Criteria or Chapel Hill Consensus 2012) who required hospitalization between July 2000 and August 2019 at a tertiary center.

Demographic characteristics, vasculitis subtype, associated organ involvement, time of disease evolution at the time of hospitalization, disease activity, causes and days of hospitalization, infectious intercurrences and laboratory data were evaluated.

Results: A total of 132 hospitalizations were recorded in 82 patients over a 19-year period, predominantly female 65.9%, with a median age at hospitalization of 48.6 years (SD: 16.2) and a mean number of days of hospitalization of 17.3 (SD: 16.3). Among the subtypes of vasculitis requiring hospitalization were Granulomatosis with Polyangiitis (GPA) 40.9%, Microscopic Polyangiitis (MAP) 25.0%, ANCA-associated undifferentiated vasculitis 8.3%, Takayasu’s arteritis 9.0%, IgA vasculitis 3.7%, Behcet’s disease 3.0%, polyarteritis nodosa (PAN) 2.2% and cryoglobulinemic vasculitis 0.7%.

Initial diagnosis of vasculitis was made during hospitalization in 31 patients (23.4%).

The most frequent cause of hospitalization was disease activity (80.3%), pulmonary 25.7%, renal 20.4%, peripheral nervous system 7.5%, central nervous system 5.3%, cutaneous involvement 6.8% and ocular involvement 6.6%. The mean activity score calculated by BVASv3 had a mean of 11.06 (SD 6.89).

Infections represented the second cause of hospitalization (34.0%) -respiratory 22.7%, urinary tract 5.3%, gastrointestinal 3.0%, septic arthritis/osteomyelitis 2.2%, skin and soft parts 0.7%-.

Other reasons for hospitalization were: surgery 2.27%, DVT 4.5% and pharmacological pancytopenia 3.0%.

Admission to the coronary unit was required in 7.58% and intensive care in 15.9% of the hospitalizations, with 78.5% mortality among those who required ICU.

A total of 14 deaths (10.6%) were recorded during the 132 hospitalizations.

In the bivariate analysis, mortality during hospitalization was associated with age (58.1 years, SD: 15.3 in patients who died vs. 47.7 years, SD: 16 in those who did not die, p= 0.03), male sex (64.2% of those who died were men vs. 35.7% who were women, p= 0.017), days of hospitalization (mean days of hospitalization in patients who died of 27.4, SD: 11.9 vs. 16.1, SD: 14.4 in patients who did not die) and the presence of respiratory infections (57.1% in patients who died vs. 18.6% in those who did not die, p= 0.0012).

In the multivariate logistic regression analysis, the only variable associated with mortality during hospitalization was the presence of respiratory infections with an OR: 8.75 (95% CI: 1.9-39.9), while the only variable shown to be protective of mortality was female sex with an OR: 0.13 (95% CI: 0.30-0.61).

Conclusion: In our center, ANCA-associated vasculitis was the predominant type of primary vasculitis requiring hospitalization, with total mortality during hospitalization associated with male sex and respiratory infections. We emphasize the importance of the latter because they are complications related to the immunosuppressive treatment of the disease.

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests: None declared.