The Contemporary Presence of Elevated Levels of Factor VIII and PAI-1 Is a Risk Factor for Recurrent Thromboembolism. A Retrospective Case–Control Study

Abstract number: P1645

Ciuti G, Marcucci R, Blagojevic J, Lapini I, Lenti M, Poli D, Antonucci E, Gensini GF, Abbate R, Prisco D

Recurrent venous thromboembolism (VTE) occurs in one third of patients after oral anticoagulant withdrawal. Several efforts have been made to identify risk factors that might be useful to stratify patients into categories at different risk of recurrences. This study aimed at evaluating the relationship between thrombophilia markers and risk of recurrent VTE in 202 patients retrospectively evaluated: 101 patients with a history of recurrent VTE (41 F/60 M; age 58 (16–90) yrs) and 101 patients, age and sex matched, with a single previous episode of VTE (46 F/55 M; age 57 (22–82) yrs). Thrombophilic risk factors were determined after oral anticoagulant treatment (OAT) withdrawal. No significant differences were detected in the prevalence of thrombophilic risk factors in the 2 groups of patients: factor V Leiden (18.8% vs. 16.8 %; OR 1.15 (95% CI; 0.55–2.42), P < 0.71), prothrombin variant (11.9% vs. 9.9%; OR 1.25 (95% CI; 0.49–3.16), P < 0.64), lupus anticoagulant (7.9% vs. 8.9%; OR 0.86 (95% CI; 0.30–2.49), P < 0.79), anticardiolipin antibodies (10.9% vs. 15.8%; OR 0.63 (95% CI; 0.27–1.48), P < 2.9), elevated levels of factor VIII:C (>150%) (52.5% vs. 43.6%; OR 1.44 (95% CI; 0.82–2.52, P < 0.20), elevated levels of PAI-1 antigen (>40 mg/dL) (19.8% vs. 13.9%; OR 1.57 (95% CI; 0.73–3.39), P < 0.25), high levels of lipoprotein (a) (>300 mg/L) (24.8% vs. 32.7%; OR 0.67 (95% CI; 0.36–1.25), P < 0.21) and hyperhomocysteinemia (33.7% vs. 22.8%; OR 1.75 (95% CI; 0.93–3.29, P < 0.08). We checked for interaction between thrombophilic risk factors investigated and we documented that the contemporary presence of high levels of factor VIII:C and PAI-1 was associated with a significant higher risk of recurrent VTE (OR 3.59 (95% CI; 1.13–11.43), P < 0.03). This result remained significant after adjustment for age, sex, acquired and thrombophilic risk factors (OR 3.74 (95% CI; 1.16–12.0), P < 0.027). In conclusion, our findings indicate that the contemporary presence of elevated levels of factor VIII:C and PAI-1 is associated with the higher risk for recurrent VTE.