Clinical predictors of recurrent venous thromboembolism: a single institute experience in Korea

Abstract

INTRODUCTION: Racial disparities in incidence rate as well as risk factors for venous thromboembolism (VTE) exist between Asian and Western populations. Moreover, predictors for recurrent VTE were not identified in Asians. Thus, this study was undertaken to investigate risk factors for recurrent VTE events in Korean people. MATERIALS AND METHODS: Three hundred-three patients newly diagnosed as VTE were enrolled from Seoul National University Hospital. Recurrence rate based on risk factors for VTE were investigated. Cumulative incidence of recurrent VTE was calculated by the Kaplan and Meier method. Independent predictors for VTE were determined using Cox proportional hazards model. RESULTS: After a median follow-up of 44 months, 24 (8%) of 303 patients relapsed for a total observation time of 1,217 patient-year. Cumulative incidences of recurrent VTE were 3% at 1 year, 10% at 5 years, and 18% at 8 years. Independent predictors for recurrent VTE were presence of residual thrombosis (hazard ratio [HR]=3.1, 95% confidence interval [CI] 1.0-9.3; p=0.044), antiphospholipid syndrome (APS) (HR=4.3, 95% CI 1.0-19.0; p=0.052), and age 50 years or younger (HR=2.5, 95% CI 1.0-6.6; p=0.053) by multivariate analysis. Residual thrombosis and APS remained predictive of recurrence by the anticoagulation-period stratified analysis. CONCLUSIONS: In contrast to Western populations, Korean patients with VTE had the lower recurrent rate. Extended anticoagulation is necessary for Korean patients with residual thrombosis or APS.