Urinary excretion of iPF2\u3b1-III predicts the risk of future thrombotic events. A 10-year follow-up

Objective: F2-isoprostanes derived by arachidonate peroxidation link platelet activation and atherothrombosis. We evaluated whether urinary excretion of 8-iso-PGF2\u3b1 that follows a methionine loading test predicts future thrombotic events. Methods: Among those referred for a methionine loading test, 96 unrelated subjects (54 males/42 females, 52/96 with a history of thrombosis) were chosen for a lifelong follow-up. Results: During 10 years of such follow-up, 39 new events occurred in 29 subjects, 25 of whom having a history of thrombosis. Mean post-methionine loading (PML) excretion of 8-iso-PGF2\u3b1 was higher (p<0.05) among patients that developed new thrombotic events as compared with those who did not. New events occurred in 14 subjects (58.3%) among those of the upper quartile and in 3 (12.5%) among those of the lowest quartile of PML-8-iso-PGF2\u3b1 excretion (RR:9.80; 95%CI:2.28-42.05, p=0.002). PML-8-iso-PGF2\u3b1 OR:4.78, p=0.007), a history of thrombosis at baseline (OR:5.52, p=0.012), smoking habits (OR:4.97, p=0.020), and visceral obesity (OR:3.19, p=0.045) predicted new thrombotic events. Only PML-8-iso-PGF2\u3b1 predicted arterial events (OR:9.97, p=0.004) in this setting. Conclusion: oxidative stress that follows a methionine loading test, as reflected by urinary excretion of 8-iso-PGF2\u3b1, predicts the risk of future thrombotic events

Mild antithrombin deficiency and risk of recurrent venous thromboembolism: a prospective cohort study

BACKGROUND - : Antithrombin deficiency, defined by antithrombin levels of 80%) and were followed up for a mean of 8.70 years to assess the incidence of VTE recurrence. A total of 823 patients (mean age, 48.3 years; 41.9% male) were enrolled. Recurrent VTE occurred in 253 patients (3.53% per patient-year). With stratification for antithrombin levels, VTE recurrence occurred in 19 patients with antithrombin levels 80% (3.31% per patient-year). After adjustment for major VTE risk factors and for anticoagulation duration, the risk of VTE recurrence was significantly higher in patients with antithrombin levels 80%. When the population was stratified according to the presence or absence of major risk factors for the index event, the association remained significant only in patients with unprovoked VTE. CONCLUSIONS - : The presence of mild antithrombin deficiency (70-80% antithrombin) in patients with unprovoked VTE is associated with a significantly increased risk of recurrence and should be taken into account when the duration of secondary prevention is determined