Risk factors for venous thromboembolic events in patients with rheumatoid arthritis

Abstract

Objective: to determine the incidence and risk factors of venous thromboembolic events (VTEE) in patients with rheumatoid arthritis (RA).Subjects and methods. The investigation enrolled 362 patients (302 women and 60 men) with RA fulfilling the 2010 American College of Rheumatology/European League Against Rheumatism criteria. The patients' mean age was 53.7±13.3 years; the disease duration was 12.4±10.9 years. All the patients were treated at the V.A. Nasonova Research Institute of Rheumatology in the period 2014 to 2015. Each patient underwent standard clinical examination of peripheral joints. RA activity was assessed with DAS28. There was a questionnaire survey that included traditional risk factors for VTEE and risk factors that might be due to RA and its therapy.Results and discussion. 34 (9.9%) patients were found to have VTEE during their hospitalization or in their history. In 32 of them thromboses were located in the veins of the lower extremities, namely 18 and 14 patients had thromboses in the distal and proximal segments, respectively. One patient was recorded to have upper extremity vein thrombosis and another had central retinal vein thrombosis. Lower extremity deep vein thrombosis was complicated by pulmonary thromboembolism in one case. Multivariate analysis has shown that the risk factors of VTEE in RA patients are bed care, heart failure, varicose vein disease, and oral administration of glucocorticoids (GC) and intraarticular GC administration (>5 injections); the weighted coefficients of the risk factors are 1.0, 0.92, 3.13, 0.02, and 0.52, respectively. According to the model obtained (p < 0.0001), the risk of VTEE can be predicted using the following formula: Z = 1.0 × bed care (yes, 1 / no, 0) + 0.92 × heart failure (yes, 1 / no, 0) + 3.13 × varicose vein disease (yes, 1 / no, 0) + 0.02 × oral GC use (yes, 1 / no, 0) + 0.52 × intraarticular GC administration (>5 injections; yes, 1 / none, 0).Conclusion. The risk of VTEE should be assessed to timely prescribe adequate prophylactic treatment and to prevent thrombotic events in RA. The classification function value Z = 1.65 identifies groups of patients at high and low risk for VTEE. Accordingly, the value Z >1.65 determines the high risk of thrombosis; in this case it has a sensitivity of 64%, a specificity of 82%, and a positive prognostic accuracy of 80%.

Keywords

• rheumatoid arthritis
• venous thrombosis
• venous thromboembolic events
• risk factors