Risk factors of deep venous thrombosis in a cohort of Chinese patients

Abstract

INTRODUCTION: Despite the great impact of deep venous thrombosis (DVT) on health, there are few published studies on underlying risk factors of DVT in Chinese patients. Pulmonary embolism (PE) is frequently unsuspected or undiagnosed. OBJECTIVES: To investigate the risk factors and prevalence of PE in a cohort of Chinese patients with DVT at a single medical center. METHODS: A retrospective review of patients with DVT from August 2013 to May 2016 was performed. Demographic data was retrieved from electronic medical record system. Risk factor of DVT and incidence of PE were analyzed using SPSS. RESULTS: A total of 94 patients (49 female, 52.1%) were included in this study. The mean age of patients was 54.2 ± 17.2 (range 25 to 88) years old. Most of them (75 patients, 80%) had acute DVT. Majority of the patients’ thrombosis was located at the left leg (52 patients, 53.3%). The other locations including right lower limb (29 patients, 30.9%), bilateral lower limbs (8 patients, 8.5%) and left subclavian vein (4 patients, 4.3%). Femoral vein was involved in 32 patients (34%), while iliac vein thrombosis was identified in 30 patients (31.9%). Limb swelling and pain were presented in 87 (92.6%) and 83 (88.3%) patients, respectively. The most common causes of DVT were immobility (30.8%), trauma or surgery (20.2%) and malignancy (8.5%). Contrast CT scan of the lung was performed in 50 patients who had proximal DVT, 27 patients (54%) had PE, however, only one was symptomatic. The dosage of warfarin was 3.6 ± 1.6 mg to achieve a target INR of 2.0-3.0. Revascularization was identified in 54 (91.5%) out of 59 patients who had follow-up duplex ultrasound. CONCLUSION: Immobility, trauma and surgery are still the most common risk factors for DVT. The incidence of silent PE in patients who had proximal DVT was high.