Heart failure is characterised by activation of haemostasis. We sought to explore the prognostic impact of deranged haemostasis in chronic heart failure. In stable, optimally managed outpatients with chronic heart failure, baseline levels of <em>prothrombin</em> <em>fragment</em> F<em>1</em>+<em>2</em>, D-dimer, and tPA and PAI-<em>1</em> antigens were determined. Clinical follow-up was obtained and the rate of events (heart failure related deaths or hospitalisations) was recorded. We included <em>1</em>95 patients [3<em>2</em>.3% female, NYHA class II (66.<em>2</em>%) or III (33.8%), mean age 7<em>1</em> years]. During a median follow up of 693 (interquartile range [IQR] 574-788) days, 63 (30.9%) patients experienced an event; those with an event had higher levels of tPA antigen (median <em>1</em><em>1</em>.8 [IQR 8.7-<em>1</em>4.0] vs. 9.4 [7.9-<em>1</em><em>2</em>.<em>1</em>] microg/l; p = 0.033) and D-dimer (938 [485-<em>1</em><em>2</em>69] vs. 6<em>2</em>0 [37-<em>1</em>076] microg/l; p = 0.0<em>1</em>8). However, on Cox multivariate analysis, only tPA levels above optimal cut-off value of <em>1</em>0.<em>2</em> microg/l (but not D-dimer) emerged as an independent predictor of prognosis (HR(adjusted) <em>2</em>.695, 95% confidence interval <em>1</em>.<em>2</em>33-5.363; p = 0.0<em>1</em>7). Our findings suggest that elevated tPA antigen levels are an independent prognostic predictor in patients with chronic stable heart failure.

Despite modern stent technology and effective antiplatelet therapy, metallic stents carry the risk of (sub)acute thrombosis. Our aim was to examine short-term differences in platelet deposition and coagulation activation between biodegradable polylactide (PLA), heparin-polycaprolactone-L-lactide-coated polylactide (hepa-P(CL95/L-LA5)-PLA), and stainless steel (SS) stent struts. Gel-filtered platelets (GFP) and platelet-rich plasma (PRP) were labeled with <em>1</em>0 nM (3)H-serotonin. Platelet deposition was measured after incubation of the stent struts in human serum albumin-coated wells at 37 degrees C in either GFP or PRP. Platelet morphology was studied by scanning electron microscopy (SEM). For coagulation activation, the stent struts were incubated in either PRP or platelet-poor plasma (PPP), anticoagulated with D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone (PPACK), followed by measurement of fibrinogen, thrombin time (TT), <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> (F<em>1</em>+<em>2</em>), and thrombin-antithrombin complex (TAT). SS showed adherence of larger amounts of GFPs than did PLA at a platelet density of 300 x <em>1</em>0(6)/mL (p < 0.05). Furthermore, representative SEM studies showed more platelet spreading on SS than on PLA stent struts. Between PLA and SS, coagulation activity did not differ at any assessment. Based on prolonged TT values in plasma, the heparin coating strongly inhibited coagulation (p < 0.05). The values of soluble TAT and F<em>1</em>+<em>2</em> for PLA were similar to those of controls, i.e., to incubated suspensions without a stent strut. In conclusion, when compared with stainless steel, both PLA and hepa-P(CL95/L-LA5)-PLA appear hemocompatible as intravascular stent materials.

The activation of the purified <em>prothrombins</em> from human, bovine, and chicken species have been studied. Chicken <em>prothrombin</em> activation, similar to bovine <em>prothrombin</em>, resulted in the formation of a <em>1</em>6<em>1</em> residue <em>prothrombin</em> <em>fragment</em> <em>1</em>, a <em>1</em><em>1</em>3 residue <em>prothrombin</em> <em>fragment</em> <em>2</em>, and chicken thrombin with a 49 residue A chain and a B chain of approximately <em>2</em>60 residues. When human <em>prothrombin</em> is converted to thrombin, the resulting thrombin is shorter from the amino-terminus of the A chain by <em>1</em>3 residues (human <em>prothrombin</em> <em>fragment</em> 3). The vitamin K-dependent regions of all three species are very similar in sequence (33 of 46 residues identical for all three species). The regions of internal homology observed within the human and bovine <em>fragments</em> are apparently also present within the chicken <em>fragments</em>, indicating that the partial gene duplication which resulted in the evolution of a <em>prothrombin</em> molecule of greater size than the other vitamin K-dependent coagulation proteins occurred prior to the divergence of birds and mammals over 300 million years ago.

OBJECTIVE

Nephrotic syndrome (NS) is associated with numerous blood coagulation abnormalities and a marked predisposition to thromboembolism. Fibrin formation within the glomeruli occurs in various forms of human and experimental glomerulonephritis and may play an important role in progressive glomerular injury. The aim of this study was to measure the plasma concentrations of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) and intravascular thrombin generation markers and to analyze their relationships in patients with primary glomerulonephritis.

METHODS

The study population comprised 57 patients (mean age 35.<em>2</em> years; range <em>1</em>8-63 years) with primary glomerulonephritis: 36 with NS (NS group) and <em>2</em><em>1</em> without (non-NS group). The control group consisted of <em>2</em>4 sex- and age-matched healthy volunteers. TF and TFPI antigen, <em>prothrombin</em> <em>fragment</em> F <em>1</em>+<em>2</em> (PF <em>1</em>+<em>2</em>) and thrombin-antithrombin III complex (TAT) concentrations in plasma were estimated using commercially available kits.

RESULTS

Serum TF and TFPI concentrations in both the NS and non-NS groups were higher than those observed in the control group. Moreover, there were significant differences in TF and TFPI concentrations between the NS and non-NS groups. TF:TFPI ratios in both the examined groups were constant and significantly higher than those in the control group. Positive correlations between TF and both PF <em>1</em>+<em>2</em> and TAT concentrations in the total cohort of patients were shown. Furthermore, a positive correlation between TF and TFPI concentrations was observed.

CONCLUSIONS

Our data support the hypothesis concerning activation of coagulation pathways in patients with primary glomerulonephritis. An inadequate TFPI concentration as a result of an elevated TF:TFPI ratio characterizes not only patients with clinical manifestations of NS but also patients with mild proteinuria.

OBJECTIVE

To compare the thrombosis markers for thrombosis and fibrinolysis in patients undergoing hip versus knee arthroplasty.

METHODS

Seven women aged 38 to 6<em>1</em> years who underwent total hip arthroplasty (THA) and 7 women aged 57 to 67 years who underwent total knee arthroplasty (TKA) were studied. Thromboprophylaxis was given before and after surgery. In patients undergoing TKA, an automatic pneumatic tourniquet was used. Blood samples were drawn (<em>1</em>) before surgery (control value), (<em>2</em>) at wound closure (immediately before release of the tourniquet in TKA), and (3) 4 hours after surgery. Thrombosis markers (<em>prothrombin</em> <em>fragment</em> <em>1</em>.<em>2</em> [F<em>1</em>.<em>2</em>], plasmin/ alpha<em>2</em>-antiplasmin complex [PAP], and D-dimer) of the <em>2</em> groups were compared.

RESULTS

The F<em>1</em>.<em>2</em> level increased significantly at wound closure and remained elevated 4 hours after surgery in the THA group, whereas it was unchanged at wound closure but increased significantly 4 hours after surgery in the TKA group. The PAP level was constant peri- and post-operatively in the THA group, whereas it increased significantly 4 hours after surgery in the TKA group. The D-dimer level increased significantly at wound closure and 4 hours after surgery in the THA group, whereas it was unchanged at wound closure but increased significantly 4 hours after surgery in the TKA group.

CONCLUSIONS

Systemic thrombin generation starts perioperatively in THA and after tourniquet deflation in TKA, indicating that wound blood must reach the systemic circulation to activate the relevant mediators.

An increased risk of thrombosis has been described in patients with hypereosinophilic syndromes, including Churg-Strauss syndrome (CSS). We report the case of a 43-year-old man with CSS who presented with asthma, pansinusitis, blood eosinophilia (9650/microL), peripheral neuropathy, cutaneous eosinophilic vasculitis, and a positive result for antineutrophil cytoplasmic antibodies. An analysis of plasma during active disease revealed elevated levels of <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> (marker of thrombin generation) (83<em>2</em> pM; normal range, 68-<em>2</em><em>2</em>9 pM) and D-dimer (marker of fibrin degradation) (<em>2</em>300 ng/mL; normal range, <em>1</em>30-<em>2</em>50 ng/mL), which indicate an increased risk of thrombosis. Both parameters returned to normal values during remission after immunosuppressive treatment. Skin histology showed leukocytoclastic vasculitis with numerous eosinophils in the dermal infiltrate. Immunohistochemistry revealed expression of tissue factor by skin-infiltrating eosinophils, as confirmed by colocalization with eosinophil cationic protein, a classic marker of eosinophil granulocytes. In conclusion, we present a patient with active CSS and a prothrombotic state that reverted during remission achieved by immunosuppressive therapy.

There is some clinical evidence that cyclosporine A (CyA) is associated with thrombotic complications of bone marrow and renal transplantation. We investigated plasma concentrations of lipoprotein(a) [Lp(a)], a potentially atherothrombotic lipoprotein, and hemostatic and vascular status in ten patients with aplastic anemia receiving CyA, eleven patients not taking it, and 38 age-matched healthy controls. Patients receiving CyA had significantly higher concentrations of plasma fibrinogen (P < 0.05), <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> (F<em>1</em> + <em>2</em>; P < 0.05), plasminogen activator inhibitor-<em>1</em> (PAI-<em>1</em>; P < 0.05), and von Willebrand factor antigen (P < 0.05) than did patients not taking CyA. Plasma concentrations of Lp(a) were higher in CyA-treated patients than those not receiving it (P < 0.05) or healthy controls (P < 0.05). The difference in the Lp(a) concentration between controls and patients who did not receive CyA-treatment was not significant. Our results suggest that hypercoagulability is likely to occur during CyA therapy. Further, the presence of high concentrations of Lp(a) may accelerate the process of atherosclerosis and increase thrombotic events in patients receiving long-term CyA.

The objective of our study was to examine the changes in coagulation parameters and inflammatory reaction over the course of <em>1</em>5 days in patients with severe sepsis. We tried to identify mechanisms by which sepsis-induced pathophysiological changes may influence the effectiveness of subcutaneously (SC) administered enoxaparin 40 mg once daily. A total of <em>1</em>6 patients (8 men, 8 women; age 35-83 years) meeting the inclusion criteria of severe sepsis were enrolled in this study. The follow-up was performed on days <em>1</em>, <em>2</em>, 3, 6, 9, <em>1</em><em>2</em>, and <em>1</em>5 of hospitalization at the intensive care unit (ICU). Blood coagulation (activated partial thromboplastin time [aPTT], <em>prothrombin</em> time [PT], fibrinogen, antithrombin (AT), protein C [PC], D-dimer, <em>fragment</em> <em>1</em>.<em>2</em> [F<em>1</em>.<em>2</em>], factor Xa [FXa] inhibition) and inflammatory reactants (interleukin 6 [IL-6], C-reactive protein [CRP], orosomucoid, alpha-<em>1</em>-antitrypsin) were tested. The mean FXa inhibition was 0.<em>1</em>7 (+ or - 0.<em>1</em>7) IU/mL. The arbitrarily established range of FXa inhibition for prophylaxis, 0.<em>2</em> to 0.4 IU/mL, was reached in <em>2</em><em>2</em> cases (<em>2</em>0%), while in 74 cases (68%), it was below and in <em>1</em>3 cases (<em>1</em><em>2</em>%) above the aforementioned range. Factor Xa inhibition positively correlated with AT (r = .4<em>2</em>; P < .00<em>1</em>) and PC (r = .45; P < .00<em>1</em>) activities. A negative correlation was found between the FXa inhibition and alpha-<em>1</em>-antitrypsin concentrations (r = -.33; P = .0<em>1</em>) but only in the subgroup with alpha-<em>1</em>-antitrypsin concentrations>> or = <em>2</em>.<em>2</em> g/L. We confirmed that in most patients with sepsis, the prophylaxis with enoxaparin did not lead to the required FXa inhibition. The inhibition of FXa by enoxaparin depends mainly on the AT and PC activities.

In patients with stable coronary heart disease (n = <em>1</em>,00<em>1</em>) we investigated the influence of tissue factor (TF) and TF pathway inhibitor (TFPI) polymorphisms on thrombin generation in vivo, measured by <em>prothrombin</em> <em>fragment</em> (F) <em>1</em> and <em>2</em>, and the potential to generate thrombin ex vivo, measured by the calibrated automated thrombogram assay. Additionally, circulating levels of TF and TFPI were correlated to the different parameters of thrombin generation. The TF 5466 and TFPI -399 polymorphisms associated with higher thrombin generation in vivo, the latter also with a prolonged lag time of the thrombin generation ex vivo(p < 0.05 for all).The TF -<em>1</em>8<em>1</em><em>2</em> TT and the TF -603 GG genotypes were associated with lower peak thrombin and a decreased average net rate of thrombin activation during the propagation phases (p ≤ 0.05), and the TFPI -33 TC genotype with prolonged lag time (p < 0.05) and additionally time to peak (p = 0.06). Strong correlations between TFPI levels, <em>prothrombin</em> <em>fragment</em> <em>1</em> and <em>2</em> as well as calibrated automated thrombogram parameters were observed.

Recognition of the central role of thrombosis in the pathogenesis of cardiovascular disease has prompted growing interest in the association of haemostatic variables with cardiovascular disease. In investigating the predictive value of haemostasis markers, a promising type of measurement is that of the activation products of coagulation and fibrinolysis: <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> (F<em>1</em>+<em>2</em>), fibrinopeptide A (FPA), soluble fibrin,thrombin-antithrombin (TAT), plasmin-antiplasmin(PAP) complexes and D-dimer. D-dimer was most extensively studied and there is substantial evidence that D-dimer is a strong, consistent predictor of cardiovascular events in the general population and inpatients with cardiovascular disease. Data on other markers are considerably less abundant and more controversial. The prognostic value of these markers remains to be fully defined in future epidemiological and clinical studies.

OBJECTIVE

We assessed the impact of completing the Hotter'n Hell Hundred (HHH), an annual <em>1</em>64 km road cycling event performed in a hot environment, on hemostatic balance in men.

METHODS

Sixteen men who completed the ride in <6 h were included in this study. Plasma samples were collected on that morning of the ride (PRE) and immediately on the completion of the ride (IP). Primary hemostasis was assessed by platelet count and von Willebrand factor antigen (vWF:Ag). Coagulation was assessed by measuring <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> (PTF <em>1</em> + <em>2</em>) and thrombin-antithrombin complex (TAT), whereas fibrinolysis was assessed by plasminogen activator inhibitor antigen (PAI-<em>1</em> Ag), tissue plasminogen activator (tPA Ag), and D-Dimer analyses.

RESULTS

Compared to PRE, increases (p < 0.00<em>1</em>) were observed at IP for platelets (39 %), vWF:Ag (65 %), PTF <em>1</em> + <em>2</em> (47 %), TAT (8<em>1</em> %), tPA Ag (<em>2</em>3<em>1</em> %), PAI-<em>1</em> Ag (<em>1</em>48 %), and D-Dimer (54 %). PRE PAI-<em>1</em> Ag concentrations were directly related to BMI and waist circumference (p < 0.05). D-Dimer concentrations at IP correlated positively with age (p < 0.05).

CONCLUSIONS

Completing the HHH activated the coagulation and fibrinolytic systems in balance. Age was positively correlated with IP D-Dimer concentrations. Additionally, participants displaying a larger BMI and waist circumference exhibited a positive correlation with PRE PAI-<em>1</em> Ag concentrations.

We have employed molecular dynamics simulations to understand the properties of the gamma-carboxyglutamic acid (Gla) domains of human <em>prothrombin</em> <em>fragment</em> <em>1</em> (residues <em>1</em>-<em>1</em>44) and factor IX (residues <em>1</em>-47). The simulations are based on (<em>1</em>) the crystal structure of bovine <em>prothrombin</em> <em>fragment</em> <em>1</em> in the presence of calcium and (<em>2</em>) our subsequent simulation of the solution structure for which we found accommodation of the long range ionic forces critical. In addition, we have estimated the solution structures for key mutant proteins [<em>prothrombin</em> (Gla6 to Asp and Gla<em>1</em>6 to Asp) and factor IX (Gly<em>1</em><em>2</em> to Ala)]. The simulations for the latter two mutants do not stabilize, a result in concert with the known biological data.

Although coronary bypass graft surgery has increased the survival and quality of life of many individuals, patients remain at risk of restenosis and thrombotic occlusion of the coronary arteries and bypass grafts. In the screening period for participation in the multicenter Post Coronary Artery Bypass Graft (Post CABG) trial, the effects of <em>1</em> mg daily warfarin were evaluated using paired patient samples collected prior to and after at least <em>2</em><em>1</em> days of treatment. In stable patients (n = 40; 39 males <em>1</em> female; 5<em>1</em>-74 years old) who previously had undergone coronary artery revascularization (<em>1</em>-<em>1</em>0 years), no alterations in <em>prothrombin</em> time, international normalized ratio (INR), <em>prothrombin</em> <em>fragment</em> <em>1</em>.<em>2</em>, or the hemostatic risk factors factor VII antigen and coagulant activity, von Willebrand's factor, fibrinogen, tPA, or PAI-<em>1</em> were associated with the <em>1</em> mg daily warfarin treatment. The observations reported here supported the Post CABG Studies Steering Committee decision to treat patients with <em>1</em>-4 mg warfarin daily adjusted to achieve INRs not to exceed <em>2</em>. 0 consistent with low-intensity therapy.

OBJECTIVE

To evaluate the impact of a 9<em>1</em>-day extended regimen combined oral contraceptive (<em>1</em>50 μg levonorgestrel [LNG]/30 μg ethinylestradiol [EE] for 84 days, followed by <em>1</em>0 μg EE for seven days [Treatment <em>1</em>]) compared with two traditional <em>2</em><em>1</em>/7 regimens (<em>2</em><em>1</em> days <em>1</em>50 μg LNG/30 μg EE [Treatment <em>2</em>] or <em>1</em>50 μg desogestrel [DSG]/30 μg EE [Treatment 3], both with seven days' hormone free), on several coagulation factors and thrombin formation markers.

METHODS

Randomised, open-label, parallel-group comparative study involving healthy women (<em>1</em>8-40 years). The primary endpoint was change from baseline in <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> (F<em>1</em> + <em>2</em>) levels over six months.

RESULTS

A total of <em>1</em>87 subjects were included in the primary analysis. In all groups, mean F<em>1</em> + <em>2</em> values were elevated after six months of treatment. Changes were comparable between Treatments <em>1</em> and <em>2</em> (least squares mean change: <em>1</em>70 pmol/L and <em>1</em>58 pmol/L, respectively) but noticeably larger after Treatment 3 (least squares mean change: 59<em>2</em> pmol/L). The haemostatic effects of Treatment <em>1</em> were comparable to those of Treatment <em>2</em> and noninferior to those of Treatment 3 (lower limit of 95% confidence interval [- <em>1</em>8.3 pmol/L]>> - <em>1</em>30 pmol/L).

CONCLUSIONS

The LNG/EE regimens had similar effects on F<em>1</em> + <em>2</em>. Noninferiority was demonstrated between extended regimen LNG/EE and DSG/EE.

BACKGROUND

Oral contraceptives (OC) in the presence of factor V Leiden mutation (FVL) markedly increase the risk of venous thromboembolism (VTE). Little is known about the OC and FVL-related alterations in fibrin clot properties.

METHODS

Plasma fibrin clot permeability (K(s)) and efficiency of lysis, reflected by clot lysis time (CLT) and the rate of D-dimer release from clots (D-D(rate)) induced by recombinant tissue plasminogen activator (tPA) were determined in <em>2</em>5 women with a family history of VTE who were heterozygous for FVL [FVL(+/-) - twice, on third-generation OC and after their discontinuation. Female non-carriers of FVL, matched for demographics, using OC and after their discontinuation served as controls (n=<em>2</em>5). All participants had no personal history of VTE.

RESULTS

OC discontinuation in FVL(+/-) women resulted in shortened CLT (-9%), and increased K(s) (+4%) and D-D(rate) (+<em>1</em>.4%; all p<0.0<em>1</em>). Alterations in fibrin clot properties were associated with decreased <em>prothrombin</em> <em>fragments</em> <em>1</em>+<em>2</em> (F<em>1</em>+<em>2</em>) (-8%), plasminogen activator inhibitor-<em>1</em> (PAI-<em>1</em>) antigen (-<em>1</em><em>1</em>%), and thrombin activatable fibrinolysis inhibitor (TAFI) activity (-<em>2</em>0%; all p<0.0<em>1</em>). During OC use FVL(+/-) carriers compared with non-carriers had higher platelet count, activity of PAI-<em>1</em>, TAFI, and tPA, as well as prolonged CLT and higher D-D(max), along with lower D-D(rate) and K(s). Multiple regression analysis adjusted for fibrinogen and age, showed that PAI-<em>1</em> antigen and TAFI activity independently predicted CLT in FVL(+/-) women on OC.

CONCLUSIONS

FVL(+/-) is associated with hypofibrinolysis in apparently healthy women and third-generation OC administration unfavorably alters plasma clot characteristics in female FVL(+/-) carriers with a family history of thrombotic events.

BACKGROUND

Thrombin generation has a key role in the pathophysiology of hemostasis. Research has focused on the intraoperative course of hemostasis, while little is known about postoperative hemostatic activation. Thrombin generation assays quantify the potential for thrombin generation ex vivo and may be useful for determining hypercoagulability. The thrombin dynamics test (TDT) assesses the initial kinetics of thrombin formation. We hypothesized that there would be an increase in thrombin generation as well as thrombin capacity after cardiac surgery.

METHODS

Two hundred twenty patients undergoing primary coronary artery bypass grafting or aortic valve replacement (AVR) surgery were prospectively enrolled. Patients undergoing AVR received warfarin beginning on the second postoperative day. In addition to <em>prothrombin</em> <em>fragment</em> (F(<em>1</em>+<em>2</em>)), TDT, d-dimer, and troponin T were assessed. Blood samples were obtained preoperatively, at the end of the operation, 4 hours postoperatively, and the morning of postoperative days (PODs) <em>1</em>, 3, and 5. The primary end point was the change of thrombin dynamics on POD <em>1</em>.

RESULTS

In all patients, F(<em>1</em>+<em>2</em>) peaked at the end of the operation and remained significantly elevated until POD 5. Compared with baseline and after an initial decrease, TDT was found to be significantly elevated on POD <em>1</em>. After coronary artery bypass graft, TDT remained significantly elevated, whereas in AVR patients with warfarin treatment, TDT was significantly reduced on PODs 3 and 5.

CONCLUSIONS

After cardiac surgery, thrombin generation continues, accompanied by a high thrombin-generating capacity and elevated fibrinogen levels. This constellation suggests a marked procoagulopathic state in the postoperative period with the potential to aggravate the risk of thromboembolic complications. Warfarin treatment after AVR significantly reduced thrombin-generating capacity.

This is the first study to examine the hypothesis that prolonged sitting is associated with procoagulant changes in the local lower-limb venous system. A comparison was made with upper-limb venous changes. Changes in markers of thrombin generation, fibrinolysis, endothelial perturbation and haemoconcentration were analysed as <em>1</em>0 healthy adult male participants sat for 8 h. The change in foot volume was estimated. Subjective venous thromboembolism assessment was undertaken hourly, along with <em>2</em>-week and 4-week safety follow-up for clinical events. Expected increases in median <em>prothrombin</em> <em>fragments</em> <em>1</em> and <em>2</em>, thrombin-antithrombin complex and D-dimer were not observed in either limb. An increase greater than 45% in the median tissue plasminogen activator and plasminogen activator-<em>1</em> molar ratio (t-PA/PAI-<em>1</em>), and a decrease greater than <em>1</em>5% in median soluble thrombomodulin were noted in both limbs. Median haematocrit decreased minimally (<em>1</em>%) in the lower limbs, while the foot volume increased by 4%. Subjects experienced vague symptoms after 6 h of sitting, but none developed symptomatic venous thromboembolism. Upper and lower-limb changes in biomarkers did not correlate, except those in t-PA/PAI-<em>1</em> ratio and plasminogen activator-<em>1</em>. Significant correlation was found between changes in the lower-limb t-PA/PAI-<em>1</em> ratio and right foot volume. This study originally reveals that even in the lower limbs, prolonged daytime cramped sitting is not associated with significant procoagulant changes in healthy adult male volunteers, and confirms a previous observation that local lower-limb venous changes are not identically reflected in the upper limbs.

OBJECTIVE

Variability in responsiveness to clopidogrel is a clinical problem in secondary prevention after cerebral ischaemia which has been suggested to be linked to competitive metabolization of clopidogrel and cytochrome P450 (CYP) 3A4-oxidated statins such as simvastatin. We assessed the hypothesis that simvastatin, in contrast to CYP <em>2</em>C9-metabolized fluvastatin, reduces clopidogrel-mediated platelet inhibition.

METHODS

We performed a randomized, double-blind, double-dummy, two period crossover study in <em>1</em>3 patients with cerebral ischaemia (8F, 5 M), aged 64.<em>1</em> ± 8.0 years (mean ± SD). After a <em>1</em>4 day period in which all patients received 75 mg clopidogrel day(-<em>1</em>) , patients additionally received either <em>2</em>0 mg simvastatin day(-<em>1</em>) or 80 mg fluvastatin day(-<em>1</em>) for <em>1</em>4 days. Regimens were crossed over after a <em>1</em>4 day wash-out period and switched regimens were continued for another <em>1</em>4 days. Platelet aggregation, clopidogrel active metabolite (CAM) plasma concentrations and routine laboratory parameters including <em>prothrombin</em> time (PT) Quick percent value were assessed at baseline and following each treatment phase.

RESULTS

Clopidogrel reduced platelet aggregation in all patients as expected. Platelet aggregation and CAM plasma concentrations were unaltered when simvastatin or fluvastatin was added to clopidogrel. Simvastatin decreased PT Quick percent value (decrease from <em>1</em>09 ± <em>1</em>0.5% to <em>1</em>03 ± <em>1</em><em>1</em>%, P < 0.05) when combined with clopidogrel but there was no such change following treatment with fluvastatin and clopidogrel.

CONCLUSIONS

Our data indicate that treatment with CYP 3A4-metabolized simvastatin does not jeopardize clopidogrel-mediated inhibition of platelet aggregation. After co-administration of simvastatin and clopidogrel we observed a decrease in the PT Quick percent value which could be due to simvastatin-induced reduction of activity of <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em>.

OBJECTIVE

Thrombin, a central enzyme in the clotting cascade, plays a role not only in thrombosis but also in the progression of atherosclerosis. We studied the relationship between <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> (F<em>1</em>+<em>2</em>), a specific marker of thrombin generation in vivo, and carotid intima-media thickness (IMT), an index of subclinical atherosclerosis.

METHODS

We examined <em>1</em>8<em>1</em> asymptomatic middle-aged subjects (mean age 55.6 years, 76.7% men) free of overt clinical atherosclerotic disease. F<em>1</em>+<em>2</em> was measured by enzyme-linked immunosorbent assay and IMT by duplex ultrasonography of carotid artery. Multiple linear regression analysis was used to assess the relationship between the <em>2</em> parameters.

RESULTS

Compared with individuals in the lowest tertile of F<em>1</em>+<em>2</em>, those in the upper tertile (>0.55 nmol/L) showed significantly higher IMT (P<0.0<em>1</em>). In correlation analysis, a positive relationship was found between plasma F<em>1</em>+<em>2</em> and carotid IMT. F<em>1</em>+<em>2</em> also correlated positively with cholesterol (P<0.008) and low-density lipoprotein cholesterol (P<0.005), but not with blood pressure or body mass index. In the multivariate analysis, the association of F<em>1</em>+<em>2</em> with carotid IMT remained significant (P<0.00<em>1</em>) after adjustment for age, sex, body mass index, systolic blood pressure, cholesterol, diabetes, and smoking.

CONCLUSIONS

In a population sample of adults without clinically overt atherosclerotic disease, the plasma levels of F<em>1</em>+<em>2</em> were significantly associated with carotid IMT, suggesting a relationship between thrombin generation and the development atherosclerosis.

To screen for risk of embolism, we investigated the association between the presence of left atrial (LA) thrombus by transesophageal echocardiography (TEE) and blood coagulation tests, including thrombin-antithrombin III complex (TAT), plasminogen activator inhibitor <em>1</em> (PAI-<em>1</em>), plasmin-alpha <em>2</em>-plasmin inhibitor complex (PIC), D-dimer, tissue plasminogen activator (tPA), free tPA, tPA.PAI-<em>1</em> complex, <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> and fibrin degradation product E (FDP-E) in 40 patients with atrial fibrillation (Af) (<em>1</em>3 males, <em>2</em>7 females, mean age 76 +/- 8 yrs). Blood coagulation tests were performed in <em>2</em><em>1</em> control subjects with sinus rhythm (<em>1</em><em>2</em> males, 9 females, mean age 75 +/- 4 yrs). LA thrombi were detected in the appendage of 8 patients and in the atrium of 6 patients. Severe atherosclerotic plaque with thrombi in the thoracic aorta were detected in 6 patients without LA thrombi. FDP-E, D-dimer and PIC increased significantly in patients with LA thrombi or aortic plaque in comparison with controls with sinus rhythm. In patients with Af, <em>2</em>5 of them (group A) has more than 4 abnormal coagulation values out of 9 tests and <em>1</em>5 of them (group B) had abnormalities in less than 3 tests. LA thrombi or aortic plaque were detected in <em>1</em>8 patients in group A and <em>2</em> patients in group B (7<em>2</em>% vs <em>1</em>3%, p < 0.0<em>1</em>). In 4 of 6 patients with large LA thrombi, the thrombi were resolved after administration of warfarin. Before administration of warfarin, tPA, PA-<em>1</em> and tPA.PA-<em>1</em> complex levels were higher in the two patients whose thrombi did not resolve.(ABSTRACT TRUNCATED AT <em>2</em>50 WORDS)

OBJECTIVE

To study various markers of blood coagulation and fibrinolysis in relation to the extension of deep vein thrombosis (DVT), and to compare the diagnostic usefulness of these markers as screening tests for excluding DVT.

METHODS

A clinical study of patients admitted to an emergency unit.

METHODS

Ostra Hospital, Göteborg, Sweden.

METHODS

One hundred and five patients with a clinical suspicion of DVT.

METHODS

Phlebography was used as the reference method for a diagnosis of DVT. Small distal thromboses as well as large proximal thromboses were included. Plasma D-dimer as well as other markers of coagulation and fibrinolysis were analysed.

RESULTS

Twenty-eight proximal and <em>2</em>0 distal DVTs were found. Plasma D-dimers (one ELISA and two latex assays), fibrin monomer, <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> (F<em>1</em>+<em>2</em>), thrombin-antithrombin III complex (TAT) and the t-PA-PAI-<em>1</em> complex were all significantly correlated to the extension of DVT, whilst fibronectin, tissue-type plasminogen activator (t-PA), single-chain urokinase-type plasminogen activator (scru-PA) and plasminogen activator inhibitor <em>1</em> (PAI-<em>1</em>) were not. The sensitivity was 94% for the D-dimer ELISA and one of the latex methods (latex-B), at a specificity of 60% and 68%, respectively. The negative predictive value was 9<em>2</em>% for ELISA and 93% for latex-B, and both assays showed a negative predictive value of <em>1</em>00% for proximal DVTs. Fibrin monomer, F<em>1</em>+<em>2</em>, TAT, D-dimer (latex-S) and the t-PA-PAI-<em>1</em> complex all showed lower negative predictive values (88, 84, 79, 78 and 65% respectively).

CONCLUSIONS

Sensitivity and negative predictive values for a latex assay (D-dimer latex-B) was similar to that of a D-dimer ELISA: With a sensitivity of 94% (<em>1</em>00% for proximal DVTs) such a latex assay may be included in a screening strategy for DVT at an emergency unit. However, the safety of such an approach has to be tested in other prospective studies.

BACKGROUND

In sepsis, activation of coagulation and inhibition of fibrinolysis lead to microvascular thrombosis. The Val34Leu polymorphism affects the function of FXIII by increasing the rate of FXIII activation by thrombin, which results in an increased and faster rate of fibrin stabilization. Sepsis and multi-organ failure cause disturbance of the normal balance of inflammation and coagulation, one of the most frequent causes of death in ICU patients. Research in polymorphism has shown the possible influence of FXIII in coagulation and inflammation.

METHODS

We analyzed the influence of the common FXIII Val34Leu polymorphism on inflammatory and coagulation parameters in human experimental endotoxinemia. Healthy volunteers (n = 6<em>2</em>) received <em>2</em> ng endotoxin (LPS) per kg body weight as a bolus infusion over <em>2</em> min. We developed a new mutagenic separated PCR assay for determination of the FXIII promoter polymorphism.

RESULTS

FXIII levels were higher for homozygous carriers of the FXIII polymorphism in comparison with wild-type 34 Val/Val and heterozygous 34 Val/Leu. Interestingly, persons homozygous for the FXIII Val34Leu polymorphism had lower monocyte and neutrophil counts throughout the observation period, yet <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> and D-dimer levels did not differ after LPS challenge.

CONCLUSIONS

Our findings indicate that the common FXIII Val34Leu polymorphism is associated with differences in monocyte and neutrophil cell counts in response to systemic LPS infusion in humans.

In a 6-month, randomized, double-blind study the effects of two combined oral contraceptives containing <em>1</em>50 micrograms desogestrel and either <em>2</em>0 or 30 micrograms ethinylestradiol on hemostatic parameters were investigated in <em>1</em>633 healthy women. Compared with baseline, the 30 micrograms ethinylestradiol formulation increased <em>prothrombin</em> <em>fragment</em> <em>1</em> + <em>2</em> (+7<em>2</em>.<em>2</em>%), D-dimer (+4<em>2</em>.4%) and protein C activity (+6.<em>1</em>%), whereas antithrombin-III activity (-6.3%) and protein S activity (-<em>1</em>9.7%) were decreased. The use of the <em>2</em>0 micrograms ethinylestradiol formulation was associated with the same pattern of changes, but with lower magnitude (F<em>1</em>+<em>2</em> + 6<em>1</em>.<em>1</em>%, D-dimer +36.0%, antithrombin III -5.3%, protein C +4.6% and protein S-<em>1</em>6.0%). The changes from baseline were significantly smaller in the <em>2</em>0 micrograms ethinylestradiol group for D-dimer, antithrombin III and protein S than in the 30 micrograms ethinylestradiol group (p = 0.0<em>1</em>9, p = 0.038 and p = 0.00<em>1</em>, respectively). One woman with a combined deficiency of proteins C and S developed deep venous thrombosis while using the <em>2</em>0 micrograms ethinylestradiol formulation. Use of both formulations was associated with a shift of the coagulation-fibrinolysis balance to an enhanced fibrin-generating and fibrin-degradating activity. The less-pronounced effect on hemostasis with the <em>2</em>0 micrograms ethinylestradiol preparation is reassuring with regard to thromboembolic risk in general. However, women with coagulation inhibitor deficiency should be advised not to use oral contraceptives.

OBJECTIVE

To evaluate the potential thrombogenic changes in the coagulation and fibrinolytic system related to treatment with ethinyl estradiol (<em>2</em>00 and 300 microg).

METHODS

Twenty-five healthy girls with expected final height exceeding <em>1</em>85 cm, as calculated by the method of Bayley and Pinneau, were treated with <em>2</em>00 microg or 300 microg of ethinyl estradiol. Coagulation and fibrinolytic parameters were determined before and during estrogen treatment and <em>2</em> and 4 weeks after estrogen withdrawal.

RESULTS

No difference in the effects on hemostasis was found between the <em>2</em> treatment groups. All <em>2</em>5 patients developed protein S deficiency during estrogen treatment, which in most girls lasted for 4 weeks after cessation of estrogen administration. During therapy, protein C activity increased, whereas antithrombin did not change. Plasminogen and plasmin-alpha(<em>2</em>) antiplasmin complexes significantly increased. Protein S deficiency was accompanied by significantly increased <em>prothrombin</em> <em>fragment</em> <em>1</em>+<em>2</em> and fibrinopeptide A. In contrast, thrombin-antithrombin complexes did not change.

CONCLUSIONS

High-dose estrogen treatment to reduce the final height in tall girls is associated with a reversible acquired protein S deficiency with indications of a pre-thrombotic state. Risk of venous thrombo-embolism may be enhanced, especially when additional risk factors for thrombosis are present.