The aim of this study was to determine the efficacy and safety of subcutaneous weight-adjusted dose low molecular weight heparin (LMWH) compared with oral anticoagulant (OA) in the prevention of ...recurrent venous thromboembolism. In a prospective multicenter trial, 202 patients with symptomatic proximal deep vein thrombosis (DVT) were included. As soon as the diagnosis of DVT was confirmed by phlebography, 101 were randomly assigned to receive LMWH (nadroparin) for secondary prophylaxis and 101 to receive OA (acenocoumarol). Patients in both groups were initially treated with nadroparin in a dose of 85 anti-Xa IU/kg s.c. every 12 h. Secondary prophylaxis with either nadroparin, 85 anti-Xa IU/kg s. c. once daily, or acenocoumarol was continued for at least 3 months. Three patients in the LMWH group and 6 in the OA group were excluded from analysis for various reasons. During the one-year combined secondary prophylaxis and surveillance period, 7 of of the 98 evaluable patients (7.1%) in the LMWH group and 9 of the 95 evaluable patients (9.5%) in the OA group had a documented recurrence of venous thromboembolism (Fisher's exact test, p = 0.61). Of these, 2 patients who received LMWH and 7 patients on acenocoumarol had recurrences in the 3-month period of secondary prophylaxis. Four patients (4.1%) in the LMWH group developed bleeding complications during this study period, as compared with 7 (7.4%) in the OA group (Fisher's exact test, p = 0.37). There were two major bleedings, one in the LMWH group and one in the OA group. Eleven patients died, 5 (5.1%) in the LMWH group and 6 (6.3%) in the OA group. It is concluded that nadroparin in a dose of 85 anti-Xa IU/kg s.c. once daily provides an effective and safe alternative to oral anticoagulants in the secondary prophylaxis of DVT.
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Objective. To assess the prophylactic efficacy of aspirin and a high‐dose antioxidant vitamin combination in patients with peripheral arterial disease (PAD) in terms of reduction of the risk of a ...first vascular event (myocardial infarction, stroke, vascular death) and critical limb ischaemia.
Design. Randomized, placebo‐controlled, double‐blind clinical trial with 2 × 2 factorial design.
Setting. Thirty‐seven European angiology/vascular medicine units.
Subjects. A total of 366 outpatients with stage I‐II PAD documented by angiography or ultrasound, with ankle/brachial index <0.85 or toe index <0.6; 210 patients completed the follow‐up.
Interventions. Four treatment groups: (i) oral aspirin (100 mg daily), (ii) oral antioxidant vitamins (600 mg vitamin E, 250 mg vitamin C and 20 mg β‐carotene daily), (iii) both or (iv) neither, given for 2 years.
Main outcome measure. Major vascular events (cardiovascular death, myocardial infarction or stroke) and critical leg ischaemia.
Results. Seven of 185 patients allocated aspirin and 20 of 181 allocated placebo suffered a major vascular event (risk reduction 64%, P = 0.022); five and eight patients, respectively, suffered critical leg ischaemia (total 12 vs. 28, P = 0.014). There was no evidence that antioxidant vitamins were beneficial (16/185 vs. 11/181 vascular events). Neither treatment was associated with any significant increase in adverse events. Inclusion of this trial in a meta‐analysis of other randomized trials of anti‐platelet therapy in PAD makes the overall results highly significant (P < 0.001) and suggests that low‐dose aspirin reduces the incidence of vascular events by 26%.
Conclusions. For the first time direct evidence shows that low‐dose aspirin should routinely be considered for PAD patients, including those with concomitant type 2 diabetes.
In a prospective multicenter trial, 149 consecutive patients with phlebographically proven proximal and/or distal deep vein thrombosis of the leg were randomly allocated to receive subcutaneously for ...10 days either low molecular weight heparin CY 216 (Fraxiparine) in a fixed dose or unfractionated heparin (UFH) in doses adjusted according to the activated partial thromboplastin time. Pre- and post-treatment phlebograms were assessed blindly using the Arnesen's score system in 134 patients available for analysis of the treatment efficacy. The mean phlebographic score after 10 days of treatment was significantly decreased in both groups (p less than 0.001) in comparison with the baseline score but the difference in score changes between the two groups was not statistically significant. There was an improvement in 45/68 patients (66%) in the Fraxiparine group and in 32/66 patients (48%) in the UFH group, and an increase in the thrombus size in 10/68 (15%) and 12/66 (18%), respectively. One symptomatic non-fatal pulmonary embolism and one major bleeding episode were observed in the UFH group. During a follow-up period of 3 months, two rethromboses had occurred in the UFH group and none in the Fraxiparine group. It is concluded that subcutaneous fixed dose Fraxiparine is safe and at least as effective as subcutaneous adjusted UFH in the treatment of deep vein thrombosis.
In this study we compared the antithrombotic and anticoagulant properties of sodium and calcium derivatives of pentosan polysulfate (Na-PPS, Ca-PPS), unfractionated heparin (UFH), and ...low-molecular-weight heparin (Fraxiparin). The antithrombotic effects of these agents have been investigated in an experimental thrombosis model in which rat mesenteric venules with a diameter of 20-30 microm were injured by well-defined argon laser lesions. Furthermore, the in vivo and in vitro anticoagulant activities activated partial thromboplastin time (aPTT), Heptest of these agents have been studied. Thrombus formation was significantly inhibited after s.c. injection of Na-PPS and Ca-PPS in doses >10 mg/kg. The duration of the antithrombotic effect lasted 8 h for Na-PPS and 12 h for Ca-PPS. After oral administration of Na-PPS, an antithrombotic effect was not observed. Oral application of Ca-PPS in doses >20 mg/kg significantly inhibited thrombus formation. Na-PPS and Ca-PPS markedly prolonged clotting time in aPTT and Heptest in concentrations ranging from 0.01 to 0.2 mg/ml rat PTT. Two h after s.c. administration of these agents in a dose of 10 mg/kg, the aPTT increased threefold and the Heptest 2.5-fold compared with controls. After oral application of 50 mg/kg Na-PPS and Ca-PPS, no effect on the coagulation test could be measured. Intravenous injection of UFH prolonged the Heptest after 1 min and the aPTT after 30 min. In ex vivo studies of aPTT and Heptest performed in rat plasma between 2 and 24 h after s.c. injection of 0.2 mg/kg Fraxiparin, no inhibition of any coagulation test was measured. The antithrombotic effect of 0.2 mg/kg Fraxiparin after s.c. injection was significant. Intravenous injection of 20 U/kg UFH significantly inhibited thrombus formation. The smallest antithrombotic effect was after i.v. injection of UFH.
In the present study we have compared the antithrombotic and anticoagulant properties of sodium and calcium derivatives of pentosan polysulphate (Na-PPS, Ca-PPS). The antithrombotic effect of these ...agents have been investigated in an experimental thrombosis model in which rat mesenteric venules diameter of 20-30 microm were injured by well defined Argon laser lesions. Furthermore, the in vivo and in vitro anticoagulant activities (aPTT, Heptest) of these agents have been studied. Thrombus formation was significantly inhibited after s.c. injection of Na-PPS and Ca-PPS in doses above 10 mg/kg. The duration of the antithrombotic effect lasted 8 h for Na-PPS and 12 h for Ca-PPS. After oral administration of Na-PPS an antithrombotic effect was not observed. Oral application of Ca-PPS in doses higher than 20 mg/kg significantly inhibited thrombus formation. Na-PPS and Ca-PPS markedly prolonged clotting time in aPTT and Heptest in concentrations ranging from 0.01 to 0.2 mg/ml rat PTT. Two h after s.c. administration of these agents in a dose 10 mg/kg, the aPTT increased 3-fold and Heptest 2.5-fold compared to controls. After oral application of 50 mg/kg Na-PPS and Ca-PPS no effect on coagulation test could be measured.
The objective of this study was to determine whether endogenous EFG released after submaximal physical exercise, affects platelet-endothelium interactions. Sixteen healthy male volunteers, aged 23-26 ...years, were submitted to a submaximal bicycle ergometry test. Blood for determination of EGF concentrations, platelet function studies (concentrations of beta-TG, PF4 and TXB2) and endothelium activity (LTC4 and endothelin-1,2 concentrations) was taken via an intravenous catheter before starting exercise and 15, 30 and 60 min after. A similar scheme was followed to investigate changes in the same parameters induced by a slow intravenous infusion of 0.3 mg/kg b.w. phentolamine (an alpha-adrenergic blocker) before exercise. Plasma concentrations of EGF and the markers of platelet function-beta-TG and PF4 as well as LTC4 concentrations increased only 15 min following exercise. The concentrations of TXB2, and endothelium-1,2 were almost unchanged 15 min after the submaximal bicycle ergometry test. Phentolamine markedly decreased the EGF concentrations in plasma (15 min following exercise) while at 30 and 60 min after exercise it had no effect on this parameter. No significant changes in concentrations of beta-TG, PF6, LTC4 and endothelin-1,2 after phentolamine infusion were found. These results show that increase of plasma EGF following exercise was accompanied with increase of beta-TG, PF4 and LTC4 concentrations. Inhibition of alpha-adrenergic receptors with phentolamine abolished the exercise-induced increase in plasma EGF concentration. The findings suggest that endogenous EGF may affect the platelet function and changes the reactivity of the vascular endothelium.
Von Willebrand factor antigen (vWF:Ag) is synthesized and secreted by endothelial cells. In the present study we tried to assess the relationship between plasma level of vWF:Ag and vascular damage in ...patients with vasculitis. The study was carried out on 59 patients with connective tissue diseases. Vasculitis was diagnosed by biopsies of the skin. The patients with vasculitis had a significantly elevated level of vWF:Ag; however, no significant correlation between the amount of plasma vWF:Ag and the degree of vasculitis was found. The obtained results show that the plasma level of vWF:Ag may reflect the presence of vascular, especially endothelial, damage in patients with connective tissue diseases.
The aim of this study was to investigate the effect of Nafamostat mesilate (FUT-175) on some blood platelet properties during the first hours of acute experimental pancreatitis (AEP) in dogs. A ...significant decrease in platelet count, hyperaggregability of platelets by ADP and PAF as well as an increased level of TXB2, were found in the early stage of AEP. No changes in platelet aggregation induced with AA were demonstrated. FUT-175 prevented a decrease in platelet number and inhibited platelet aggregation induced with ADP, PAF and AA when it was given immediately after induction of AEP. No evident changes in TXB2 levels in dogs treated with FUT-175 were found. Our results indicate that the positive effect of FUT-175 in AEP in part depends on its antiaggregatory action.
The role of blood platelets in the disturbed haemostasis in acute pancreatitis is not fully elucidated. The aim of this study was to evaluate the blood platelet function during the first hours of ...acute experimental pancreatitis (AEP) in dogs. AEP was induced by the retrograde injection of bile and trypsin into the main pancreatic duct. Platelet count, platelet aggregation induced with ADP, PAF, AA as well as plasma Beta-TG and TXB2 levels were determined. At 30 min after induction of AEP a significant decrease of platelet count was noted; these changes were observed until 4 th hr. At 30 min as well as at 60 min of AEP increased sensitivity of platelet aggregation to ADP was found. After that time evident decrease of platelet aggregation to ADP was shown. Platelets sensitivity to PAF was higher at 30 min of AEP whereas 60 min, 2 and 4 hrs after AEP normalization of platelet aggregation by PAF was observed. The significant increase of plasma Beta-TG and TXB2 concentrations corresponded well to changes of platelet aggregation. These results indicate that AEP affects blood platelet function with the drop of their count.
