Background: Epidemiology and clinical management of acute venous thromboembolism (VTE) are not readily available in Japan.
Methods and results: The Japan VTE Treatment Registry (JAVA) is a multicenter cohort study of consecutive patients with an objectively confirmed, symptomatic acute pulmonary embolism (PE), symptomatic acute deep vein thrombosis (DVT), or asymptomatic acute proximal DVT. Of the 1,076 patients enrolled with acute VTE, 68.7% presented with an isolated DVT; 17.0% had PE alone; and 14.4% had both. VTE management was characterized by a high rate of inferior vena cava filter insertion (40.6%), frequent thrombolysis (21.1%), and sub-therapeutic unfractionated heparin-based anticoagulation, followed by warfarin prescription, mostly targeting an international normalized ratio of 2.0 (range, 1.5-2.5). During a mean observation period of 252.5 days, 29 recurrent cases of VTE were documented, yielding an incidence rate of 3.9 per 100 patient-years. A total of 123 patients died during the study period, corresponding to a rate of 16.6 deaths per 100 patient-years. The incidence of major bleeding was 3.2% per patient-year, including 2 fatal hemorrhages and 7 intracranial hemorrhages.
Conclusions: VTE management in Japan is characterized by a highly aggressive strategy in the acute phase, in contrast to protocols that use low-level anticoagulation. The VTE recurrence rates in Japan and Western countries are similar, but mortality is higher in Japan, with significant variability depending on patient and management characteristics.