D-dimer predicts poor hospitalisation outcomes in patients with antineutrophil cytoplasmic autoantibody-associated vasculitis

Objective. The in-hospital mortality rate among patients with antineutrophil cytoplasmic autoantibody-associated vasculitis (AAV) is high. Unfortunately, there is no reliable prognostic biomarker. This study aimed to investigate whether elevated D-dimer levels can predict hospitalisation outcomes among patients with AAV. Methods. We performed a retrospective analysis at a tertiary medical centre in Seoul, South Korea, between 2005 and 2019. Patients with AAV requiring hospitalisation, whose D-dimer levels were available within one week of hospitalisation, were included; patients with known alternative reasons for elevated D-dimer were excluded. Death and intensive care unit requirements were defined as adverse outcomes. Results. In total, 61 AAV patients with a total of 100 episodes of hospitalisation were included. Median D-dimer levels were significantly higher in patients with adverse outcomes than in those without adverse outcomes (1.84 vs. 0.42 mg/dL; p=0.006). Consistently, the incidence of the adverse outcomes was significantly higher in the high D-dimer group (≥0.699 mg/dL; n = 40) than in the low D-dimer group (<0.699 mg/dL; n = 60) (35% vs. 10%; p=0.002). Multivariate logistic regression analysis revealed that a high D-dimer level was a significant risk factor for adverse outcomes (hazard ratio, 4.852; 95% confidence interval, 1.320-17.833; p=0.017). Kaplan-Meier survival analysis revealed that the high D-dimer group was associated with more 30-day in-hospital adverse outcomes than the low D-dimer group (p=0.008). Conclusion. High D-dimer levels on admission are significantly associated with adverse outcomes among patients with AAV.