Are patients with thrombophilia and previous venous thromboembolism at higher risk to arterial thrombosis?

IntroductionWhether thrombophilic disorders, which are established risk factors for venous thromboembolism (VTE), also increase the risk of arterial thrombosis is still unknown.Materials and methodsWe analyzed data from 1081 consecutive patients (649 F/432 M, 16–93 years of age) with previous VTE registered in the MAISTHRO (MAin-ISar-THROmbosis) database with regard to arterial thrombotic events and contributing risk factors. Screening for thrombophilia included testing for factor V Leiden and prothrombin G20210A mutation, antiphospholipid antibodies and activities of factor VIII, protein C, protein S and antithrombin.ResultsOf the entire study cohort, 40 patients (3.7%) had a prior myocardial infarction (MI), and 41 (3.8%) suffered a stroke. Other arterial thrombotic events were rare. Elevated factor VIII levels were more prevalent in MI patients than in controls (44.4 vs. 25.9%, p = 0.044), but after adjusting for the traditional cardiovascular risk factors, this relationship was no longer significant. We observed a higher rate of lupus anticoagulant in MI patients with an adjusted odds ratio of 3.3 (95%CI 0.84–12.8, p = 0.090). No difference in any other tested thrombophilia was observed in patients with MI or stroke relative to those without.ConclusionThe cumulative incidence of arterial thrombotic events in VTE patients is low, and the inherited thrombophilias do not seem to substantially increase the risk of arterial thrombosis.