Background Rheumatoid arthritis (RA) patients present an increased risk of venous thromboembolism (VT), an important cause of morbidity and mortality. An increased risk of VT events (VTE) may negatively influence the prognosis and clinical outcomes in RA pts. Therefore it is important to identify risk factors in RA pts (standard and associated with the disease) for prevention of VTE.
Objectives To determine prognostic risk factors for VTE in RA patients.
Methods 187 patients (F:152, M:35) with confirmed RA were analyzed, 53,8±12,8 y.o, duration of the disease 12,2±10,8 y. All patients were hospitalized in V.A. Nasonova Research Institute of Rheumatology. Patients were grouped in 2 arms: 27/187 (14,4%) pts with VTE on enrollment or with history of prior ETV; and 160/187 (85,6%) pts without prior ETV. Existing ETV risk factors were evaluated based on questionnaire survey data. Disease activity was expressed as DAS28 score which is a composite score derived from tender joint count, swollen joint count, ESR and patient's global assessment of disease activity.
Possible prognostic risk factors included age (women>55 years, men>65years), BMI, smoking, cardiovascular diseases, traumas, fractures, immobilization, pregnancy and childbirth, intake of contraceptives, diabetes mellitus (DM), intra-articular administration of glucocorticoids (GCs), cancer, duration and activity of RA.
RA activity and duration were assesses using contingency table and the χ2 test. Multivariate analysis (discriminant function classification) was used to identify other predictors of VTE.
Results Analysis of contingency table with the χ2 test showed a statically significant difference in VTE rates between the two groups – patients with high disease activity (Group 1, n=55) and patients with remission, low and moderate RA activity (Group 2, n=119). In Group 1 there were 16/55 (29,09%) pts with VTE and in Group 2 - 11/119 (9,24%), p<0,00118. There was no statically significant difference in duration of the disease between the groups. Multivariate analysis revealed the following factors predisposing to VTE: arterial hypertension, heart failure, immobilization, pregnancy and childbirth, DM, intra-articular GCs; weighted coefficients: 1.728; 1,119; 1,012; 0.610; 1,424; 0.643. The following function for VTE prediction is suggested:
Z =1,728 * hypertension (Yes-1/No-0) + 1.119 * heart failure (Yes-1/No-0) + 1.012 * immobilization (Yes-1/No-0) + 0.61 * pregnancy and childbirth (yes-1/No-0) + 1.424 * DM (Yes-1/No-0) + 0.643 * intra-articular GCs (Yes-1/No-0).
The threshold value of Z=2,632 allows to predict VTE events in RA pts with 70% sensitivity, 70% specificity and 70%positive predictive relevance.
Conclusions Adverse prognostic factors for VTE development in RA patients are disease activity, hypertension, heart failure, immobilization, pregnancy and childbirth, diabetes mellitus, and intra-articular administration of glucocorticoids.
Disclosure of Interest None declared