#1828 Venous thromboembolic events in ANCA associated vasculitis patients—data from Croatian referral center

Abstract

Abstract Background and Aims Our aim was to investigate the prevalence of venous thromboembolic events (VTE) in a cohort of patients with ANCA-associated vasculitis (AAV) and define factors associated with the frequency of VTE considering there is data on high incidence of VTE in AAV patients. In these cohorts VTE occurred mostly early in the course of disease. Method This study included 114 consecutive AAV patients with biopsy proven renal involvement in the period from 2007-2017. Patients were classified according to clinical: granulomatosis with poliangitis (GPA), microscopic polingitis (MPA) and eosinophilic granulomatosis with poliangitis (EGPA) and serological phenotype: MPO-ANCA positive, PR3-ANCA positive, MPO- and PR3-ANCA positive and ANCA-negative. Ordinal variables were analysed using logistical regression test. Statistical analysis was done in MedCalc Statistical Software version 18.11.6 (MedCalc Software Bvba, Ostend, Belgium). Results In the cohort there were 64 (56%) females, mean age was 58 (IQR 16-84) with mean follow up time 46.9 months (IQR 1-127). Clinically there were 84 (73%) patients with MPA, 26 (22%) with GPA and 4 (5%) with EGPA. Serologically there were 20% PR3-ANCA, 54% MPO-ANCA, 8% MPO- and PR-3 ANCA positive patients and 18% ANCA-negative patients. Mean serum creatinine levels (SCr) was 380.9 μmol/l (IQR 65-1402). Mean BVAS (Brimingham vasculitis score) at the time of diagnosis of AAV was 17 (IQR 5-50) and at the time of VTE 0, 9 (0-22). Mean body weight was 71kg (IQR 48-110) and mean CRP was 84 mg/ml (IQR 0, 3-256). During the follow up 7 (6.14%) of the patients had VTE, with 4 having VTE in first month after the diagnosis and other two at month 14 and 19. Logistic regression showed the connection of weight (P = 0.0052) and CRP (0.0138) with VTE with odds ratio of 1,0829 for CRP (1.003-1.027) and 1.0150 for weight (1.0284-1.1736) respectively. There was no statistical significance for clinical or serological phenotype being associated with VTE nor for other clinical or laboratory parameters. Conclusion In our cohort patients with AAV were at risk of VTE, particularly within the first year following onset of disease. In this cohort the frequency of VTE did not depend of clinical or serological AAV phenotype, age or gender. Only CRP and body weight were associated significantly with VTE occurrence. Despite VTE rates in AAV patients, routine anticoagulation is not recommended in AAV patients, given the potential risk of bleeding complications. Prospective studies are needed to assess VTE risk stratification in AAV patients and to evaluate the both benefits and potential risks ratio of prophylactic anticoagulation in AAV patients.