Prothrombin fragment 1+2 and thrombin–antithrombin complex levels in patients with inherited APC resistance due to factor V Leiden mutation

Inherited activated protein C (APC) resistance is a newly described pathological condition associated with familial thrombophilia. A recent report on a family with APC resistance showed increased levels of prothrombin fragment 1+2 (F1+2) in the affected individuals. No data concerning thrombin–antithrombin complex (TAT) levels in patients with inherited APC resistance are presently available. The aim of this study was to assess the plasma levels of F1+2 and TAT in patients with inherited APC resistance due to factor V (F.V) Leiden mutation and to evaluate F1+2 and TAT levels in symptomatic and asymptomatic patients with the defect (‘carriers’) as compared to their family members having no evidence of F.V Leiden mutation (‘non-carriers’). One hundred and twenty-nine individuals belonging to 30 families with inherited APC resistance due to F.V Leiden mutation were studied. F1+2 and TAT levels were determined using two commercially available ELISA kits and cut-off values were defined as the higher limits of normal ranges obtained in healthy volunteers. Out of the 129 family members investigated, 36 were non-carriers, 85 were heterozygous and eight homozygous for F.V Leiden mutation. Thrombosis had occurred in 2/36 (6%) non-carriers, in 36/85 (42.3%) heterozygous and in 5/8 (63%) homozygous. Median levels of F1+2 and TAT were above cut-off values in carriers, whereas they were below in non-carriers. An overall percentage of 68.8% of carriers exhibited F1+2 levels above the cut-off value as compared to 38.9% of non-carriers. For TAT, an overall percentage of 63.4% of carriers presented with levels above the cut-off compared with 28% of non-carriers. In conclusion, patients with inherited F.V Leiden mutation may exhibit increased levels of F1+2 and TAT. There are no differences in F1+2 and TAT median levels among symptomatic and asymptomatic carriers. The percentage of carriers of F.V Leiden with levels of F1+2 and TAT above cut-off appears to be higher than that found in other clotting inhibitors defects and in this respect the defect might be considered different. However, these findings and the presence of a high percentage of non-carriers presenting with increased F1+2 and TAT levels may suggest the possible coexistence in these families of other unknown defects predisposing to thrombosis.     

肝素联合前列腺素E1治疗下肢深静脉血栓形成的研究

目的:观察普通肝素联合前列腺素E1在治疗下肢深静脉血栓形成(DVT)中的作用。方法:下肢DVT患者17例,分为治疗组9例,对照组8例;治疗组由普通肝素联合前列腺素E1及常规治疗,对照组为低分子量肝素及常规治疗。治疗1、7 d后检测下肢血流、纤维蛋白原、D-二聚体及疼痛及肢体肿胀情况。结果:治疗1 d后,2组患者肢体疼痛及肢体肿胀情况较治疗前趋向改善,但所有指标2组比较均差异无统计学意义;治疗7 d后,治疗组较对照组下肢血流情况明显改善(P<0.05),纤维蛋白原下降明显(P<0.05)。结论:普通肝素联合前列腺素E1治疗下肢DVT可能较单一运用低分子肝素效果为佳,且安全性亦好。     

Treatment of deep venous thrombosis in congenital antithrombin III deficiency with low molecular weight heparin

A 19-year old male patient with hereditary antithrombin III type I deficiency was admitted for thrombosis of the right iliac, femoral and popliteal veins. Treatment with a low molecular weight heparin resulted in recanalization of the veins confirmed by phlebography. After two weeks of treatment, the drug was replaced by another low molecular weight heparin and this was followed, 3 weeks later, by a documented relapse of thrombosis.     

Cost-effectiveness of low-molecular-weight heparin in the treatment of proximal deep vein thrombosis

OBJECTIVE: To estimate the cost-effectiveness of low-molecular-weight heparin (LMWH) in the treatment of proximal lower extremity deep venous thrombosis. DESIGN: Cost-effectiveness analysis that includes the treatment of the index case and simulated 3-month follow-up. SETTING: Acute care facility. PATIENTS AND PARTICIPANTS: Hypothetical cohorts of 1,000 patients who present with proximal deep venous thrombosis. INTERVENTIONS: Intravenous unfractionated heparin (UH), LMWH (40% at home, 60% in hospital), or selective UH/LMWH (UH for hospitalized patients and LMWH for patients treated at home). MEASUREMENTS AND MAIN RESULTS: The outcomes were recurrent thrombosis, mortality, direct medical costs, and marginal cost-effectiveness ratios from the payer’s perspective. At the base-case and under most assumptions in the sensitivity analysis, the LMWH and the selective UH/LMWH strategies dominate the UH strategy i.e., they result in fewer cases of recurrent thrombosis and fewer deaths, and they save resources. The savings occur primarily by decreasing the length of stay. The LMWH strategy resulted in lower costs as compared with the UH strategy when the proportion of patients treated at home was more than 14%. Treating 1,000 patients with the LMWH strategy as compared with the UH/LMWH strategy would result in 10 fewer cases of recurrent thrombosis, 1.2 fewer deaths, at an additional cost of $96,822; the cost-effectiveness ratio was $9,667 and $80,685 per recurrent thrombosis or death prevented, respectively. CONCLUSIONS: Treatment with LMWH leads to savings and better outcomes as compared with UH in patients with lower extremity deep venous thrombosis. The selective UH/LMWH strategy is an alternative option. Presented in part at the 20th annual meeting, Society of General Internal Medicine, Washington, DC, May 1–3, 1997.     

Failure of thrombin-antithrombin III complexes in the diagnosis of deep vein thrombosis.

Plasma thrombin-antithrombin III (T-AT) complexes are reputed to be an indirect manifestation of thrombin generation, and a role for their determination in the diagnosis of deep vein thrombosis (DVT) has been advocated. In order to evaluate the accuracy of T-AT complexes assay for DVT diagnosis, in 166 consecutive outpatients with clinical suspicion of the disease, plasma concentration of T-AT complexes was measured immediately before venography by means of an enzyme-linked immunosorbent assay kit. The result of the T-AT complexes assay was elevated in 29 of the 48 patients with DVT (sensitivity, 60%). The T-AT complexes levels were within the normal range in 104 of the 118 patients with normal venograms (specificity, 88%). The positive and the negative predictive value were 67% and 85%, respectively. The authors conclude that the T-AT complexes assay is of little value for the diagnosis of DVT in outpatients.     

Management of acute proximal deep vein thrombosis: pharmacoeconomic evaluation of outpatient treatment with enoxaparin vs inpatient treatment with unfractionated heparin

OBJECTIVES: A landmark Canadian randomized controlled clinical trial compared treatment of acute proximal vein thrombosis via low-molecular-weight heparin (LMWH) [enoxaparin] administered primarily at home with IV unfractionated heparin (UH) in the hospital. Results demonstrated equivalent safety and efficacy for home care with enoxaparin with a reduction in cost. Our objective was to validate these findings in the routine practice setting of a US health maintenance organization. DESIGN: Retrospective analysis of medical and administrative records of health-plan members meeting inclusion-exclusion criteria of the Canadian trial during the period from 1995 to 1998. SETTING: Staff-model health maintenance organization serving New Mexico. PATIENTS:Persons presenting as outpatients from 1995 to 1996 or from 1997 to 1998 with acute, proximal deep vein thrombosis (DVT) diagnosed by duplex ultrasonography. INTERVENTIONS: Initial anticoagulant therapy of IV UH administered in the hospital (from 1995 to 1996 group, n = 64) or subcutaneous LMWH (enoxaparin) administered primarily at home (from 1997 to 1998 group, n = 65), followed by warfarin therapy. RESULTS: No statistically significant differences were observed in the number of recurrent venous thromboembolic events (p = 0.36) or bleeding events (p = 1.0). Mean +/- SD cost per patient was 9,347 dollars +/- 8,469 in the enoxaparin group compared with 11,930 dollars +/- 10,892 in the UH group, a difference of - 2,583 dollars (95% bootstrap-adjusted asymmetrical confidence interval, - 6,147 dollars, + 650 dollars). CONCLUSIONS: Retrospective replication of the Canadian study in a US routine (managed) care setting found similar clinical and economic outcomes. Treatment of acute proximal DVT with enoxaparin in a primarily outpatient setting can be accomplished safely and yields savings through avoidance or minimization of inpatient stays.     

Prothrombin fragments F1+2, thrombin-antithrombin III complexes, fibrin monomers and fibrinogen in patients with coronary atherosclerosis

We determined the plasma levels of prothrombin fragment F1+2, thrombin-antithrombin III complexes (TAT), fibrin monomers (FM), D-dimers (DD) and fibrinogen in 57 patients with angiographically verified graded coronary artery disease (CAD) free of concomitant peripheral atherosclerosis, cerebrovascular disease or diabetes mellitus and a group of 21 apparently healthy controls. Blood was collected from the antecubital vein through atraumatic venipuncture prior to the angiographic procedure. Plasma levels of hemostatic markers were related to the presence and graded severity of CAD. The levels of prothrombin fragment F1+2 (1.74+/-0.11 vs. 1.0+/-0.07 nmol/l, P<0.001), FM (41.6+/-5.5 vs. 7.42+/-3.05 nmol/l, P<0.001), TAT (15.6+/-2.7 vs. 2.96+/-0.32 microg/l, P<0.001) and fibrinogen (3.64+/-1.3 vs. 3.08+/-0.33 g/l, P<0.01) were significantly higher in patients with CAD compared to controls, while there was no difference regarding the fibrinolytic system represented by DD (441.6+/-58.9 vs. 337.4+/-42.05 microg/l, n.s.). Within the CAD group, patients with extensive coronary atherosclerosis (> or =2 vessel disease) had significantly higher values for prothrombin fragment F1+2 (1.89 vs. 1.57 nmol/l, P = 0.04), FM (50.7 vs. 29.8 nmol/l, P = 0.03), and a trend to significance was noted for fibrinogen (3.9 vs. 3.3 g/l, P = 0.07) suggesting that blood coagulability was related to the severity of the disease and that hemostatic markers of thrombin activity represent a useful tool to identify patients with a latent hypercoagulable state with a higher susceptibility to sustain coronary thrombosis.     

Adjusted subcutaneous heparin or continuous intravenous heparin in patients with acute deep vein thrombosis. A randomized trial

Study Objective: To determine the efficacy and safety of adjusted subcutaneous calcium heparin compared with continuous intravenous calcium heparin as the initial treatment for acute deep vein thrombosis. Design: Randomized control trial. Setting: University-affiliated general hospital. Patients: Of 111 consecutive patients considered, 103 had acute proximal or calf vein thrombosis confirmed by ascending venography and met all other eligibility criteria. Interventions: Patients were randomly assigned to receive subcutaneous or intravenous heparin. The subcutaneous regimen consisted of an initial dose of 15,000 U, adjusted thereafter to prolong the activated partial thromboplastin time to 50 to 70 seconds. The continuous intravenous regimen was begun as a bolus injection of 5000 U, followed by an infusion of 1250 U/h, adjusted to maintain the activated partial thromboplastin time at 50 to 70 seconds. Measurements and Main Results: There was no significant difference in the rate of new pulmonary embolism between the two groups, as defined by new high-probability defect on repeat ventilation-perfusion scintigrams of the lung in 96 (93%) of the patients after 7 to 10 days of treatment. Five of forty-seven patients in the subcutaneous group and 5 of 49 in the intravenous group developed pulmonary embolism (95% confidence interval [CI] for the difference, -13.1% to 12.2%). Similarly, there was no significant difference in the frequency of hemorrhagic complications. Five of fifty-one patients in the subcutaneous group and 5 of 52 in the intravenous group had hemorrhagic complications (95% CI for the difference, -11.2% to 11.6%). Conclusion: Adjusted subcutaneous calcium heparin may be an effective and safe alternative to continuous intravenous calcium heparin in the initial treatment of acute proximal deep vein thrombosis.     

The use of intravenous recombinant hirudin in the treatment of deep vein thrombosis in a patient with an acute heparin allergy

We report a case in which intravenous heparin, given for the treatment of acute deep vein thrombosis, precipitated an acute allergic reaction, and an alternative anticoagulant, recombinant hirudin, provided rapid and successful therapeutic intervention.     

The home treatment of deep vein thrombosis with low molecular weight heparin, forced mobilisation and compression.

BACKGROUND: The aim of this prospective study was to analyse a group of patients with DVT (deep vein thrombosis) treated at home with LMWH (low-molecular weight heparin), compression and intensive mobilisation and to evaluate its feasibility, efficacy and safety from possible risks of pulmonary embolism. METHODS: From March 1997 to September 1999, 96 consecutive patients with diagnosed DVT were enrolled in a prospective study and treated at home with enoxaparin (Clexane Rh ne-Poulenc) administered subcutaneously at doses depending on body weight (1 mg/kg) b.i.d. for a minimum of seven days. Oral anticoagulants were started two days before discontinuing LMWH and given later for three months according to the haemocoagulation parameters. All patients wore elastic second degree compression stockings during the whole period of treatment and for 12 months there after. They were encouraged to walk 1-3 km daily. The sites of thrombosis were ilio-femoral vein--38 patients (40%), femoral or popliteal vein--32 patients (33%), crural veins--26 patients (27%). According to our surgical criteria two years ago 17 patients would have been operated on and trombectomy performed. The diagnosis was made by compression ultrasonography using a colour duplex scanner (Acuscan 125), by contrast phlebography, and platelet scintigraphy (Tromboscint test). Perfusion-ventilation scintigraphy of the lungs was performed only if there were clinical signs or even a suspicion of pulmonary embolism and on all patients with iliofemoral thrombosis. Perfusion gamagraphy of lungs was carried out on 51 patients where thrombosis was localised in proximal veins. RESULTS: In 27 patients there were signs of non-fatal pulmonary embolism (53%), but only seven patients (26%) suffered mild non-specific clinical signs; 20 patients with diagnosed pulmonary embolism (74%) were symptom-free. Out of 96 patients, three admitted to hospital (3%), 67 (70%) injected LMVH themselves and felt comfortable. Eight to 12 weeks after this treatment control sonography and phlebography were carried out in 70 patients to assess the localisation and progress of the thrombosis. In 51% (36 patients) partial and 31% (22 patients) total recanalisation was found. Five out of 96 complained of minor bleeding (5%). No thrombocytopenia was noticed. The first five days on home treatment were crucial. All patients were able to walk and live at home without difficulty. None of our patients with proximal deep vein thrombosis used a vena cava filter. CONCLUSIONS: Home treatment of DVT is possible and is effective, safe and less costly on average and per patient 40% in costs was saved compared with those of a hospital stay in spite of the greater expense of LMWH. The patients who received LMWH spent a mean of 1.2 days in the hospital, as compared with 12.7 days for the standard-heparin group.     

Prothrombin fragment F1 + 2 and thrombin-antithrombin III complex are useful markers of the hypercoagulable state in atrial fibrillation.

It is well known that atrial fibrillation (AF) is one of the most important diseases that predispose patients to thrombosis. We have attempted to identify patients with AF in the hypercoagulable state by measuring molecular markers such as thrombin-antithrombin III complex (TAT) and prothrombin fragment 1 + 2 (PTF) and determining the effect of antithrombotic therapy on these markers; 83 patients with AF were studied. Increased levels of plasma TAT and PTF were more frequently observed in patients with AF and associated mitral stenosis than in patients with AF alone. In cases of AF without mitral stenosis, plasma levels of TAT and PTF were significantly lower in those patients receiving antithrombotic agents (aspirin or warfarin) than in those receiving no antithrombotic agents. Furthermore, plasma levels of PTF were significantly lower in patients given warfarin than in those receiving aspirin. These results suggest that (1) patients with AF and mitral stenosis who are not given warfarin are in an extremely hypercoagulable state and (2) some patients with AF without mitral stenosis who are not given antithrombotic agents are also moderately hypercoagulable. In vivo activation of blood coagulation was more effectively controlled in patients receiving warfarin than in those taking aspirin.     

The use of thrombus precursor protein, D-dimer, prothrombin fragment 1.2, and thrombin antithrombin in the exclusion of proximal deep vein thrombosis and pulmonary embolism.

We examined various nonSTAT commercially available coagulation activation markers in an attempt to help diagnose or exclude the often subtle clinical presentations of proximal deep vein thrombosis (PDVT) and pulmonary embolism (PE). Fifty-five patients presenting to the Emergency Department were completely assessed. Eleven patients were diagnosed with PDVT, six patients were diagnosed with PE, and three patients were diagnosed with both PDVT and PE. Thrombus precursor protein (TpP) excluded the diagnosis in 19 of the 35 patients negative for PDVT and/or PE, D-Dimer in 15 patients, prothrombin fragment 1.2 in 17 patients, and thrombin-antithrombin (TAT) in 14 patients. Both the TpP and TAT enzyme-linked immunosorbent assay (ELISA) tests had 100% sensitivity and negative predictive value for evaluating PDVT and/or PE. The TpP ELISA had the highest specificity (54%) of all four markers studied.     

Plasma factor VII and thrombin–antithrombin III levels indicate increased tissue factor activity in sickle cell patients

Although the mechanisms involved in the persistent clinical complications of sickle cell disease have not yet been fully delineated, previous studies suggest that sickle cell (HbSS) patients have a disposition to generate more thrombin and plasma in vivo than normal subjects. The reasons for the impaired regulation of haemostasis in HbSS patients is poorly understood. We report studies evaluating the extent to which in vivo coagulation and fibrinolysis are altered in HbSS patients in steady state. The concentrations of total factor VII (F(VII)t), factor VII zymogen (F(VII)z), thrombin-antithrombin III (TAT), fibrinopeptide A(FPA), and fibrin D-dimer in plasmas of 50 normal controls (HbAA) and 45 HbSS steady state patients, were measured using sensitive and specific enzyme-linked immunoassays. The average plasma concentration of F(VII)t, in sickle cell plasma was significantly lower than that of the control subjects (0.70 +/- 0.19 U/ml versus 1.16 +/- 0.41 U/ml), whereas F(VII)z in the patients and controls were 0.47 +/- 0.15 U/ml and 1.15 +/- 0.33 U/ml respectively, P < 0.001. Both measures of factor VII suggest a higher factor VII turnover in sickle cell disease. The mean concentration of TAT in the plasma of HbSS patients were significantly higher than those of HbAA controls (371 +/- 44 pM versus 42 +/- 2 pM) (P < 0.001), a difference that is strongly indicative of higher rates of in vivo thrombin generation by HbSS patients. Plasmas of HbSS patients had significantly higher concentrations of FPA compared to those of the control subjects (12.85 +/- 1.96 ng/ml versus 4.22 +/- 0.37 ng/ml) (P < 0.001). The D-dimer levels were also higher in the HbSS than control plasmas (1029.6 +/- 58.6 ng/ml versus 224.3 +/- 27.6 g/ml) (P < 0.001), with the patients' values being indicative of enhanced fibrinolysis. These results strongly suggest accelerated in vivo coagulation and fibrinolysis in HbSS patients even during steady state. They are consistent with the hypothesis that haemostasis is less tightly regulated in the HbSS patients than in HbAA controls. The altered regulation of haemostasis may contribute to the initiation of vaso-occlusive processes associated with sickle cell painful episodes.