Diagnosis and treatment of venous thromboembolism and clinical application of inferior vena cava filter in China

This study investigated the trend of venous thromboembolism (VTE) in China during the past 10 years and assessed the clinical application of inferior vena cava filters (IVCFs).A survey designed to investigate the diagnosis and management of VTE, specifically the application of IVCFs, was distributed nationally from January 2009 to December 2019. The respondents were mainly designated medical professionals and were asked to complete 4 major and 61 minor items in the survey.A total of 53 medical centers, including 27 radiologic and 26 vascular surgery centers, from 21 provinces in China participated in the study. These centers had diagnosed and treated 171,310 patients with VTE; 83,969 were inpatients (49%). During a 10-year period, an increasing trend of VTE diagnosis and inpatient management, 3.8-fold and 4.8-fold, respectively, was observed. The characteristics of the inpatients were as follows: 15% bilateral lower extremity deep vein thrombosis (DVT), 27% right lower extremity DVT, and 58% left lower extremity DVT. Anticoagulation therapy included unfractionated heparin with vitamin K antagonists (8%), low-molecular-weight heparin (LMWH) with vitamin K antagonists (21%), LMWH with transition to rivaroxaban (34.2%), LMWH with transition to dabigatran (2.4%), rivaroxaban alone (33.4%), and dabigatran alone (1.0%). The percentage of patients continuing anticoagulation therapy at 3, 6, 12, 24, and >24 months was 36%, 35%, 18%, 6.0%, and 5%, respectively. The in-hospital mortality for the patients with VTE was 3.2%, with DVT and pulmonary embolism responsible for 5.2% and DVT alone for 2.7%. Thrombolytic therapy was initiated for 39,046 of 83,969 patients (46.5%), including catheter-directed thrombolysis for 33,189 of the 39,046 patients (85%) and evaluation of the iliac vein using ultrasound and/or venography for 63,816 patients (76%). Urokinase was the main thrombolytic drug used (98%), followed by recombinant tissue-type plasminogen activator. Complete and partial thrombolysis was achieved in 70% and 30% of the patients, respectively. Bleeding complications were observed in 3.5% of patients, and 20% of the patients with bleeding complications required intervention. Between 2009 and 2019, 40,478 IVCFs (76% retrievable) were implanted in hospitalized VTE patients. During the enrollment period, the total number of IVCFs implanted increased by 3.8-fold, with a 4.8-fold increase in retrievable IVCFs and 7.5-fold decline in permanent IVCFs. The removal rate for the retrievable IVCFs was 72%. After IVCF implantation, 94.8% of patients received anticoagulation therapy for an average of 9.1 ± 8.6 months. The overall complication rate associated with IVCF placement was 15.5% (n = 6274 of 40,478 IVCFs), including tilting (54%), vena cava thrombosis (26.1%), caval penetration (12.6%), and migration (7.3%). No IVCF placement-related mortality occurred.A significant increase occurred in VTE diagnosis in China during the past decade. Anticoagulation therapy was the mainstay treatment, and catheter-directed thrombolysis was widely used. Most IVCFs placed were retrievable, and the use of permanent IVCFs has largely been discarded.