Physical activity improved by adherence to prophylaxis in an Italian population of children, adolescents and adults with severe haemophilia A: the SHAPE Study.

BACKGROUND: Physical activity in people with haemophilia (PWH) reduces the development of severe arthropathy, but it must be performed after regular, proper prophylaxis. Strict adherence to treatment is crucial to achieving effectiveness and established outcomes. The primary aim of this study was to collect prospective data on adherence to prophylaxis for over 36 months. A secondary aim was to verify whether adherence correlates with physical activity. MATERIALS AND METHODS: Italian patients with severe haemophilia A treated on prophylaxis with octocog alfa were included in the study. Physical findings were assessed by the Haemophilia and Exercise Project (HEP)-Test-Q and the Early Prophylaxis Immunologic Challenge (EPIC)-Norfolk Physical Activity Questionnaire; orthopaedic status was assessed by the Hemophilia Joint Health Score (HJHS). Adherence was measured as percentage of empty vials returned with respect to the prescribed amount. RESULTS: Forty-two PWH were enrolled: 31% children, 21.4% adolescents, and 47.6% adults. Type, frequency and impact of physical activities differed among the three groups. The HEP-Test-Q showed the highest impairments in the domains "endurance" and "strength/co-ordination". Eight percent of patients were classified as adherent to prophylaxis. Among them, 50% had at least one bleeding episode in the year before enrolment; this percentage dropped during the three years of the study. While remaining stable in the "non-adherent" group, the HJHS score decreased in the "adherent" patients. The mean number of school/work days lost was lower in adherent patients (from 3.4±6.8 to 0.2±0.9) than in non-adherent ones. DISCUSSION: PWH with better orthopaedic scores reported better physical performance. Adherence to long-term prophylaxis proved to be high and correlated with a reduction in bleeds, target joints, school/work days lost, and with a performance improvement in endurance sports activities over time.

Co-administration of low molecular weight heparin enhances the profibrinolytic effect of warfarin through different mechanisms.

BACKGROUND AND OBJECTIVE: Treatment with vitamin K antagonists (VKA) reduces fibrinolytic resistance through the inhibition of thrombin-mediated activation of thrombin activatable fibrinolysis inhibitor (TAFI). Because low-molecular weight heparin (LMWH) is co-administered with VKA during initiation of anticoagulant treatment, we evaluated the effect of dual anticoagulation on fibrinolytic resistance. PATIENTS AND METHODS: Two groups of patients were studied: 1) patients on stable warfarin; 2) patients starting oral anticoagulant therapy, who were evaluated during dual anticoagulation and after enoxaparin withdrawal. Only samples with an INR between 2 and 3 were compared. The resistance of clots to t-PA-induced fibrinolysis was evaluated in blood and plasma by thromboelastography (TEG) and turbidimetry, respectively. RESULTS: In patients on dual anticoagulation, blood fibrinolysis time (TEG) was significantly shorter than in patients on warfarin alone and significantly correlated with LMWH level. The profibrinolytic effect was partly ascribable to a reduction of thrombin-dependent TAFI activation: 1) thrombin and TAFIa generation were significantly reduced by dual anticoagulation; 2) the addition of enoxaparin to warfarin-blood reduced TAFI-mediated fibrinolysis inhibition. Patients on dual anticoagulation also displayed a reduction in clot strength, a phenomenon known to reduce fibrinolytic resistance. The profibrinolytic effect of LMWH co-administration was not seen in plasma, likely because TAFIa generation was below the threshold required to inhibit fibrinolysis. CONCLUSIONS: Co-administration of LMWH in patients under VKA reduces the fibrinolytic resistance of blood clots via TAFI-dependent and TAFI-independent mechanisms. Further studies are warranted to assess the clinical implications of these findings.