Increased hemostasis potential persists in women with previous thromboembolism with or without APC resistance

Background: Activated thrombin generation and depressed fibrinolysis due to the presence of activated protein C (APC) resistance with or without factor (F)V Leiden mutation are associated with development of deep venous thrombosis (DVT). Objective: A better understanding of the mechanism behind the risk of recurrence of DVT, using our new, recently developed assay of overall hemostasis potential (OHP). Patients and methods: Levels of OHP, as well as APC resistance and FV Leiden mutation, were determined in 88 women (cases) who had previously experienced DVT in connection with pregnancy, and in 25 young healthy individuals (controls). Clotting time and clot lysis time were also investigated. Results: OHP levels in the patients were increased compared with the controls. In the cases with APC resistance and the Leiden mutation this imbalance in hemostasis potential was more severe than in those without. The group with the more severe imbalance had shorter clotting times and longer clot lysis times. Conclusions: A procoagulant state perseveres in patients with a history of pregnancy-related DVT, even after the symptomatic phase is over. The mechanisms behind such an imbalance in overall hemostasis are enhanced thrombin generation and depressed fibrinolysis. These findings may underscore the need for thromboprophylaxis to prevent recurrence of thromboembolism in risk situations.