P148	Elevated lipoprotein(a) levels: a new biological marker of venous thromboembolic risk.
1F.Casals, 2G.Escolar, 3R.Deulofeu, 3E.Casals
1Thromboembolism Unit, UFMATE, CDB, Hospital Clinic, Barcelona, ES; 2Servicio Hemoterapia-Hemostasia ,Hospital Clinic, Barcelona, ES; 3Lipids Laboratory , Hospital Clinic, Barcelona, ES.

Introduction: Biological evidence suggest that lipoprotein (a)[Lp(a)] may modulate fibrinolysis. On account of this fibrinolysis dysregulation, we hypothesize, that highest Lp(a) levels could be a prothrombotic factor for venous thromboembolism (VTE). Study design: We have performed an observational study to characterize clinical and biological characteristics in a group of adult patients who presented with an episode of VTE and very high levels of Lp(a). Material and Methods: All episodes of deep venous thrombosis (DVT) and pulmonary embolism (PE) were imaging documented. Blood levels of Lp(a) were measured by an immunoprecipitation technique (SPQ TM Diasorin). Only patients whose Lp(a) values were above the upper 85th percentile (> 55 mgr/dl; median 18,4 mgr/dl) were evaluated. Additionaly hypercoagulable workup and cancer survey was carried out. Results: We found 33 patients with Lp(a) levels above the pre-established values. Sex ratio was 14 men vs. 19 women. The mean age was 62±14 years(eight patients were younger than 50). Seven out of the 33 were affected by PE and other six by iliac(5) or subclavian(1) DVT. Twenty cases were classified as of idiopathic origin. Relapse was found in 18 %. Two patients developed myocardial infarction and six had chronic limb ischemia. Three patients had malignancies. Average levels of Lp(a) were 80,8±28,2 mgr/dl(range 56–150 mgr/dl) in the population described. All patients (except one) had persistently increased levels of Lp(a) in the following years. Cholesterol levels were below 220 mg/dl in 17 patients. Hyperhomocysteinemia was found in 3 cases, APC resistance in 3 other cases and association of the three conditions in 2 more cases. No biological defects were detected in the remaining 25 patients. Conclusions: Very highest Lp(a) levels become the third persistent biological anomaly founded for us in patients with thromboembolism, after APC resistance and hyperhomocysteinemia. The high cut-off point employed minimizes the effect of large right skewness found for Lp(a) level distribution in normal health population. The alteration described is frequently associated with others thrombophilic factors, corresponded with more severe forms of the disease and did not correlate with cholesterol levels. But to demonstrate a causation for VTE will require a more high-level study.

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