The relation between thrombophilia and venous thromboembolism

Abstract

Background: Venous thromboembolism represents the third cause of cardiovascular disease after coronary artery disease and stroke with remarkable complications and high recurrence rate. Up to 50% of the new cases of venous thromboembolism are idiopathic, and patients with this condition require special care and follow up. Thrombophilic factors have a prevalence of 25 to 50% in patients with unprovoked forms of thromboembolism. Objectives: As there are not clear statistics regarding this problem in Romania, the aim of the study was to determine the prevalence of idiopathic venous thromboembolism in a group of patients with venous thromboembolism, the frequency of thrombophilia and to study the risk factors which action simultaneously. Methods: The study was performed in two emergency hospitals from Bucharest, Romania on patients with venous thromboembolism. CT scans were used to confirm pulmonary embolism and venous ultrasonography to confirm venous thrombosis. In the absence of trigger factors patients were tested for thrombophilia. Results: 176 patients were included. 112 cases (63.64%) were unprovoked (idiopathic) and only 64 (36.36%) were provoked (secondary). Idiopathic venous thromboembolism was more frequent in males, the differences between sexes being statistically significant (p<0.0001).At least one thrombophilic factor could be identified in 27.27% of cases. Thrombophilic patients experienced thrombosis at a younger age than non-thrombophilic patients (mean age 39.72±13.2 vs 60.93±18.1, p<0.0001). Factor V Leiden was the most common thrombophilia, followed by antiphospholipid syndrome. Factor V Leiden was associated with increased risk of deep venous thrombosis but not with pulmonary embolism (p=0.002). Acquired risk factors were: cancer (29 cases, 16.48%), previous venous thromboembolic episodes (35 cases, 19.89%), obesity (46 cases, 26.14%), chronic venous insufficiency (30 cases, 17.14%), hypothyroidism (4 cases, 2.27%), recently orthopedic procedures (8 cases, 4.57%), surgery (6.25%), oral contraceptives (7 cases,3.98%), pregnancy and postpartum period (2 cases, 1.14%), intravenous drug abuse (5 cases, 2.84%), congenital venous system anomalies (2 cases, 1.14%). Smoking was associated with unprovoked venous thromboembolism (p=0.039). Conclusions: The study revealed a higher frequency of unprovoked venous thromboembolism than reported in other studies. Thrombophilic factors were involved in the etiology of 27.27% of cases.The majority of cases had a multiple etiology. Male sex and smoking proved to be risk factors for unprovoked venous thromboembolism.