Incidence, Characteristics and Management of Venous Thromboembolism in Japan During 2011.

BACKGROUND: This study aimed to determine the incidence, characteristics and management of venous thromboembolism (VTE) in Japan during 2011.Methods and Results:A retrospective study assessed responses to a questionnaire regarding treating newly diagnosed VTE at all admitting hospitals throughout Japan during 2011. More individuals were diagnosed with VTE than ever before, with 16,096 cases of diagnosed pulmonary embolism (PE) and 24,538 cases of diagnosed deep vein thrombosis (DVT). Almost half (47.2%) of the PE patients had a relatively mild condition with no right ventricular overload. Similarly, almost half (43.8%) of the DVT patients had a relatively mild condition with isolated calf thrombus. Most of PE patients were treated by anticoagulation, and fewer were treated using thrombolytic agent or inferior vena cava (IVC) filter. CONCLUSIONS: The present study showed a remarkable increase in the incidence of VTE in Japan during 2011. Relatively mild conditions such as non-massive PE and isolated calf DVT were frequently diagnosed. Among PE patients, thrombolytic therapy or IVC filter implantation decreased compared with previous surveys. The appropriate management of isolated calf DVT requires further investigation.