D-dimer can be a diagnostic marker for cisplatin-related aortic thrombosis: A case report

RATIONALE

Cisplatin is one of the key drugs that is frequently used for treating various types of malignancies. Although renal and digestive toxicities are well-known cisplatin-related toxicities, attention should also be paid to acute aortic thrombosis, a relatively rare but potentially fatal disorder caused by cisplatin. Additionally, D-dimer is mainly measured to detect venous thromboembolism or disseminated intravascular coagulation, whereas its usefulness for detecting aortic thrombosis remains unclear. Here, we report a case of squamous cell lung cancer treated with cisplatin-based chemotherapy, wherein acute aortic thrombosis was diagnosed based on elevated D-dimer levels.

PATIENT CONCERNS

A 65-year-old man with stage IV squamous cell lung cancer presented with elevated D-dimer levels during treatment with second-line chemotherapy with cisplatin and S-1. Contrast-enhanced computed tomography (CT) revealed an intramural thrombus, which had not been previously identified, extending from the abdominal aorta to the common iliac artery.

DIAGNOSES

We diagnosed the patient as having acute aortic thrombosis caused by cisplatin.

INTERVENTIONS

The patient received intravenous administration of unfractionated heparin for 9 days followed by oral warfarin.

OUTCOMES

One month after initiating treatment, the patient's D-dimer levels decreased to the normal range, and contrast-enhanced CT revealed that the thrombi had nearly completely disappeared without any sequelae or organ damage.

LESSONS

Our findings revealed that cisplatin can cause acute aortic thrombosis and that regular measurements of D-dimer levels before and during chemotherapy may contribute to the early detection of acute aortic thrombosis.

CO2 artificial pneumothorax on coagulation and fibrinolysis during thoracoscopic esophagectomy

BACKGROUND

CO2 artificial pneumothorax creates a sufficient operative field for thoracoscopic esophagectomy. However, it has potential complications and continuous CO2 insufflation may impede coagulation and fibrinolysis. We sought to compare the effects of CO2 artificial pneumothorax on perioperative coagulation and fibrinolysis during thoracoscopic esophagectomy.

METHODS

We investigated patients who underwent thoracoscopic esophagectomy with (group P, n = 24) or without CO2 artificial pneumothorax (group N, n = 24). The following parameters of coagulation-fibrinolysis function: intraoperative bleeding volume; serum levels of tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), thromboelastogram (TEG), D-Dimer; and arterial blood gas levels were compared with two groups.

RESULTS

Group P showed higher levels of PaCO2, reaction time (R) value and kinetics (K) value, but significantly lower pH value, alpha (α) angle and Maximum Amplitude (MA) value at 60 minutes after the initiation of CO2 artificial pneumothorax than group N ((P < .05, all). The t-PA level after CO2 insufflation for 60 minutes was significantly higher in group P than in group N (P < .05), but preoperative levels were gradually restored on cessation of CO2 insufflation for 30 min (P > .05). There was no significant difference in D-dimer.

CONCLUSION

CO2 artificial pneumothorax during thoracoscopic esophagectomy had a substantial impact on coagulation and fibrinolysis, inducing significant derangements in pH and PaCO2.

TRIAL REGISTRATION

The study was registered at the Chinese clinical trial registry (ChiCTR1800019004).

Hemostatic effects of two desogestrel-containing combined oral contraceptive regimens: a multinational, multicenter, randomized, open-label study

PURPOSE OF INVESTIGATION

To compare the effects of desogestrel (DSG) 150 mcg/ethinyl estradiol (EE) 20 mcg for 21 days followed by either seven days of EE ten mcg (21/7-active) or no treatment (DSG/EE+no Tx) on hemostatic markers.

MATERIALS AND METHODS

This was a randomized, multicenter, open-label study that enrolled healthy premenopausal women. Non-inferiority of 21/7-active to DSG/EE+no Tx was determined if the upper limit of the two-sided 95% CI of the mean treatment difference in prothrombin fragment 1+2 (F1+2) over 24 weeks between groups was < 130 pmol/L.

RESULTS

246 subjects (n = 125, 21/7-active; n = 121, DSG/EE+no Tx) comprised the primary analysis. Mean F1+2 levels increased in both 21/7-active and DSG/EE+no Tx regimens (least square [LS] mean changes +45 pmol/L and +56.8 pmol/L, respectively). LS mean treatment difference was -11.8 pmol/L (95% CI: -54.8, 31.2).

CONCLUSION

The effect of adding EE ten mcg to the seven-day hormone-free interval of DSG/EE on F1+2 levels was non-inferior to traditional DSG/EE.

Interaction effects of temperature and ozone on lung function and markers of systemic inflammation, coagulation, and fibrinolysis: a crossover study of healthy young volunteers

BACKGROUND

Trends in climate suggest that extreme weather events such as heat waves will become more common. High levels of the gaseous pollutant ozone are associated with elevated temperatures. Ozone has been associated with respiratory diseases as well as cardiovascular morbidity and mortality and can reduce lung function and alter systemic markers of fibrinolysis. The interaction between ozone and temperature is unclear.

METHODS

Sixteen healthy volunteers were exposed in a randomized crossover study to 0.3 ppm ozone and clean air for 2 hr at moderate (22°C) temperature and again at an elevated temperature (32.5°C). In each case lung function was performed and blood taken before and immediately after exposure and the next morning.

RESULTS

Ozone exposure at 22°C resulted in a decrease in markers of fibrinolysis the next day. There was a 51.8% net decrease in PAI-1 (plasminogen activator inhibitor-1), a 12.1% net decrease in plasminogen, and a 17.8% net increase in D-dimer. These significantly differed from the response at 32.5°C, where there was a 44.9% (p = 0.002) and a 27.9% (p = 0.001) increase in PAI-1 and plasminogen, respectively, and a 12.5% (p = 0.042) decrease in D-dimer. In contrast, decrements in lung function following ozone exposure were comparable at both moderate and elevated temperatures (forced expiratory volume in 1 sec, -12.4% vs. -7.5%, p > 0.05). No changes in systemic markers of inflammation were observed for either temperature.

CONCLUSION

Ozone-induced systemic but not respiratory effects varied according to temperature. Our study suggests that at moderate temperature ozone may activate the fibrinolytic pathway, while at elevated temperature ozone may impair it. These findings provide a biological basis for the interaction between temperature and ozone on mortality observed in some epidemiologic studies.

Effects of an antisense oligonucleotide inhibitor of C-reactive protein synthesis on the endotoxin challenge response in healthy human male volunteers

Background

C‐reactive protein (CRP) binds to damaged cells, activates the classical complement pathway, is elevated in multiple inflammatory conditions, and provides prognostic information on risk of future atherosclerotic events. It is controversial, however, as to whether inhibiting CRP synthesis would have any direct anti‐inflammatory effects in humans.

Methods and Results

A placebo‐controlled study was used to evaluate the effects of ISIS 329993 (ISIS‐CRP_Rx) on the acute‐phase response after endotoxin challenge in 30 evaluable subjects. Healthy adult males were randomly allocated to receive 6 injections over a 22‐day period of placebo or active therapy with ISIS 329993 at 400‐ or 600‐mg doses. Eligible subjects were subsequently challenged with a bolus of endotoxin (2 ng/kg). Inflammatory and hematological biomarkers were measured before and serially after the challenge. ISIS‐CRP_Rx was well tolerated with no serious adverse events. Median CRP levels increased more than 50‐fold from baseline 24 hours after endotoxin challenge in the placebo group. In contrast, the median increase in CRP levels was attenuated by 37% (400 mg) and 69% (600 mg) in subjects pretreated with ISIS‐CRP_Rx (P<0.05 vs. placebo). All other aspects of the acute inflammatory response were similar between treatment groups.

Conclusion

Pretreatment of subjects with ISIS‐CRP_Rx selectively reduced the endotoxin‐induced increase in CRP levels in a dose‐dependent manner, without affecting other components of the acute‐phase response. These data demonstrate the specificity of antisense oligonucleotides and provide an investigative tool to further define the role of CRP in human pathological conditions.

The role of nitric oxide in aspirin induced thrombolysis in vitro and the purification of aspirin activated nitric oxide synthase from human blood platelets

Aspirin, a well-known inhibitor of platelet aggregation, is extensively used for the prevention/treatment of coronary artery disease. The beneficial and antithrombotic effects of the compound are related to the inhibition of platelet cyclooxygenase. It is currently believed that aspirin has no effect on the formed thrombus, which results in coronary artery disease. It was found that the exposure of platelets to 4.0 microM aspirin either in vitro or in vivo resulted in fibrinolysis of the formed "clot" produced by the recalcification of platelet-rich plasma due to the production of NO in these cells by the compound. The lysis of clot in the presence of aspirin was found to be related to the fibrinolysis with simultaneous appearance of fibrin degradation products due to the generation of serine proteinase activity by NO in the assay mixture. The aspirin activated nitric oxide synthase that catalyzed the synthesis of NO in platelets was solubilized by Triton X-100 treatment and purified to homogeneity by chromatography on DEAE cellulose and Sephadex G-50 columns. The enzyme was found to be a single chain polypeptide with M.W. 19 kDa. The treatment of human plasminogen with NO was found to directly activate the zymogen to plasmin with the production of preactivation peptide in the absence of cofactors, or cells without the formation of cyclic GMP in the assay mixture.

Prolonged exposure to inhaled nitric oxide does not affect haemostasis in piglets

OBJECTIVE

To examine possible adverse effects on haemostasis from prolonged exposure to inhaled nitric oxide (iNO).

DESIGN AND SETTING

Blinded, randomised, experimental animal study in a university animal laboratory.

INTERVENTIONS

Anaesthetised and intubated piglets received central venous, arterial, and transabdominal urinary catheters. Twelve piglets were studied with triggered pressure support ventilation breathing with an air-oxygen mixture for 30 h with nitric oxide (NO), 40 parts per million (ppm) (n = 6) or without NO gas (n = 6) added. The tests of platelet function were assessed in a separate 1-h experiment in which 12 additional animals were blindly randomised to receive intravenous acetylsalicylic acid (ASA) (n = 7) or placebo (n = 5).

MEASUREMENTS AND RESULTS

All 12 animals were clinically stable during the study period of 30 h. Haemostasis was assessed in terms of bleeding time and platelet function by Adeplat-S, reflecting platelet adhesion. Prothrombin fragment 1 + 2, fibrin D-dimer, tissue plasminogen activator and prothrombin complex were measured to investigate whether inhaled NO (iNO) had any effects on thrombin formation, fibrin formation, fibrinolysis or coagulation. All parameters including bleeding time and Adeplat-S were unaffected by iNO. ASA significantly increased bleeding time, but did not affect Adeplat-S. Nitrate in plasma and NOx (nitrate and nitrite) in urine increased significantly in pigs receiving iNO compared with controls.

CONCLUSIONS

Prolonged exposure to iNO at 40[Symbol: see text]ppm did not affect bleeding time or coagulation parameters in healthy piglets. The findings do not support the hypothesis that iNO increases the risk of bleeding in humans.

Predictive value of D-dimer plasma levels in response and progressive disease in patients with lung cancer

Patients with cancer may present with one or more circulatory markers of haemostatic activation which may be associated with tumor growth and cancer cell dissemination. In our clinical practice we observed haemostatic abnormalities with or without thrombotic episodes in cancer patients. The aim of the present study was to detect the D-dimer plasma levels in advanced-stage lung cancer patients before, during and after chemotherapy, and to determine whether there is a correlation with response rate, disease recurrence and survival, in order to estimate the possible predictive value of D-dimer plasma levels. Forty-seven/52 patients were evaluable and analysed; 38 patients had non-small-cell lung cancer (NSCLC) and 9 small-cell lung cancer (SCLC) and all were at an advanced stage or inoperable. Two (4.3%) achieved complete response (CR), 17 (36.2%) partial response (PR), and 16 (34%) had progressive disease (PD). We found that 14/19 (73.7%) patients with CR or PR showed a reduction in D-dimer plasma values and 11/16 (68.8%) with PD showed increased values; also, in patients with recurrent disease (12/13, 92.3%), D-dimer plasma levels were increased. All of the above values were statistically significant. D-Dimer plasma levels decrease or increase after response and progressive disease, respectively, and can act as a predictive factor of the evolution of the disease.

Effects of a protease inhibitor, ulinastatin, on coagulation and fibrinolysis in abdominal surgery

PURPOSE

Ulinastatin is well known to inhibit the activity of polymorphonuclear leukocyte elastase (PMNE). The PMNE concentration correlates with the activities of coagulation and fibrinolysis. The purpose of the present study was to investigate the effects of ulinastatin, a protease inhibitor, on coagulation and fibrinolysis in abdominal surgery.

METHODS

Thirty patients, aged 40 to 70 years, with American Society of Anesthesiologists (ASA) physical status I or II, scheduled for major abdominal surgery, were enrolled. Anesthesia was induced with midazolam and thiopental, and was maintained with sevoflurane, nitrous oxide in oxygen, and an epidural block. An infusion of ulinastatin, 6000 units x kg(-1) in 30 min, was started 1 h after the start of surgery in the ulinastatin group (15 patients). In the control group (15 patients), no protease inhibitors were infused. White blood cell count; platelet count; prothrombin time; activated partial thromboplastin time; and plasma concentrations of PMNE, antithrombin (AT), fibrin/fibrinogen degradation product (FDP), fibrinogen, plasminogen, plasmin-(alpha2) plasmin inhibitor complex (PIC), and thrombin-antithrombin complex (TAT) were measured before, at the end of, and 12 h after surgery.

RESULTS

TAT, PIC, and FDP after surgery were significantly lower in the ulinastatin group than in the control group. AT was decreased in the control group but not in the ulinastatin group, with significant differences between the two groups.

CONCLUSION

Ulinastatin could inhibit coagulation and fibrinolysis in abdominal surgery.

Antithrombin in sepsis revisited

As the pivotal phase III randomized controlled clinical trial on antithrombin concentrate in patients with severe sepsis did not show a beneficial effect of antithrombin treatment on 28-day mortality, the interest in the potential use of this treatment modality in sepsis has diminished. However, recent data on the effect of antithrombin administration on coagulation in combination with recent analyses from the clinical trials that were aimed to restore physiological anticoagulant pathways in patients with sepsis may revitalize the interest in antithrombin concentrate for the treatment of severe sepsis.

Reduction of D-dimer levels after therapeutic administration of antithrombin in acquired antithrombin deficiency of severe sepsis

Introduction

In acute disseminated intravascular coagulation, the effect of antithrombin (AT) administration on elevated levels of D-dimer is not well established. In the present study, we report on changes in circulating levels of D-dimer in response to administration of AT in a series of patients with acquired AT deficiency due to severe sepsis.

Methods

Eight consecutive critically ill medical patients presenting with acute disseminated intravascular coagulation associated with severe sepsis/septic shock received a single bolus infusion of AT over 30 minutes, aiming to achieve physiological AT levels. Haemostatic parameters including D-dimer were assessed prior to, 6 and 24 h after AT administration. An average of 42 ± 9 U/kg body weight was infused.

Results

Following AT substitution, elevated levels of D-dimer fell whereas AT levels rose.

Conclusion

These observations support the notion that AT can favourably affect fibrin degradation accompanying disseminated intravascular coagulation of severe sepsis.

Effects of celecoxib on high-sensitivity C-reactive protein in chronic peritoneal dialysis patients

To evaluate the effects of celecoxib, a cyclooxygenase-2 inhibitor, on the level of high-sensitivity C-reactive protein (hs-CRP), D-dimer, von Willebrand factor (vWF) and troponin-T, 46 chronic peritoneal dialysis (CPD) patients with hs-CRP equal or greater than 0.25 mg/dL were randomized to the treatment group who took 200 mg of celecoxib daily for 4 weeks or to the control group who did not take the medication. The levels of hs-CRP, albumin, D-dimer, vWF and troponin-T were measured at baseline and at 4 weeks of the study. Baseline values of all the parameters were not significantly different between the two groups. In the control group, the levels of hs-CRP, albumin, D-dimer, vWF and troponin-T did not change. In the treatment group, administration of celecoxib for 4 weeks significantly reduced hs-CRP from median 0.77 (range 0.25-7.08) to 0.39 mg/dL (range 0.11-5.22, p<0.05). The levels of albumin, D-dimer, vWF and troponin-T levels were not affected by the administration of celecoxib. These results showed that celecoxib had an antiinflammatory effect in usual dosage in CPD patients.

Effects of tranexamic acid on postoperative bleeding and related hematochemical variables in coronary surgery: Comparison between on-pump and off-pump techniques

OBJECTIVES

Bleeding and inflammation are major complications of extracorporeal circulation. Off-pump coronary artery bypass grafting may reduce the rate of complications, but it can only be applied in selected cases. Pilot studies have shown a potential benefit from the use of antifibrinolytic drugs, but efficacy in randomized double-blind studies evaluating off- and on-pump coronary artery bypass grafting has not been proved.

METHODS

We enrolled 102 patients scheduled for on-pump (n = 51) or off-pump (n = 51) coronary artery bypass grafting. Patients were separately double-blind randomly assigned to treatment with tranexamic acid (1 g as 20-minute bolus before skin incision, followed by continuous infusion of 400 mg/h, with 500 mg added to priming in patients undergoing on-pump coronary artery bypass grafting) or placebo (saline solution of equivalent volume). Bleeding in the first 24 postoperative hours was the primary outcome. Requirement for allogeneic transfusions, thrombotic complications, outcomes, and monitoring of coagulation, fibrinolysis, and inflammation were also recorded.

RESULTS

Tranexamic acid reduced total postoperative bleeding by 43% in patients undergoing on-pump coronary artery bypass grafting and by 27% in those undergoing off-pump coronary artery bypass grafting (P <.0001), with 80% reduction in bleeding exceeding 600 mL (P <.001), 58% reduction in the requirement for all allogeneic transfusions (P =.07), and no apparent effect on thrombotic complications or outcome. This was associated with a reduction in plasma D-dimer levels (P <.0001), to a greater degree in patients undergoing on-pump coronary artery bypass grafting (P <.0001), and interleukin 6 levels (P <.0001), to a greater degree in patients undergoing off-pump coronary artery bypass grafting (P <.001).

CONCLUSIONS

By affecting fibrinolysis, tranexamic acid significantly reduces bleeding both in off- and on-pump coronary artery bypass grafting and may modulate inflammation in these surgical settings.

In Vitro Effects of Poly-N-Acetyl Glucosamine on the Activation of Platelets in Platelet-Rich Plasma with and without Red Blood Cells

BACKGROUND

This study was performed to assess the effect of poly-N-acetyl glucosamine fiber slurry on plasma clotting proteins, platelets, and red blood cells in the clotting of the blood.

METHODS

Citrate phosphate dextrose whole blood was stored at 22degreesC for 48 hours to prepare platelet-poor plasma, platelet-rich plasma (PRP), and PRP plus red blood cells with hematocrit values of 20%, 35%, and 45% with and without an equal volume of poly-N-acetyl glucosamine fibers (1 mg/mL 0.9% NaCl).

RESULTS

Thromboelastogram data show that poly-N-acetyl glucosamine fibers (p-GlcNAc) significantly reduced the R time in platelet-poor plasma, PRP, and PRP supplemented with red blood cells. Poly-N-acetyl glucosamine fibers increased, but not significantly, Annexin V and factor X binding to platelets, platelet microparticles, and red blood cell Annexin V binding. Poly-N-acetyl glucosamine fibers increased the production of thromboxane B2 by PRP.

CONCLUSION

Poly-N-acetyl glucosamine slurry activates platelets.

Endothelial Damage and Activation of the Hemostatic System During Radiofrequency Catheter Isolation of Pulmonary Veins

AIMS

To determine the systemic thrombogenic effect of radiofrequency catheter isolation of the pulmonary veins (PVI) in the treatment of atrial fibrillation.

METHODS AND RESULTS

We studied endothelial damage marker (von Willebrand factor [vWf]), fibrinolysis markers (tissue plasminogen activator [t-PA], plasminogen activator inhibitor-1 [PAI-1]) and coagulation activation markers (D-dimer [DD]) in 30 patients (pts) undergoing PVI. Heparin was administered continuously after double transseptal puncture in all pts. Concentrations of vWf and t-PA were significantly increased after accomplishing PVI compared to the baseline values, and elevated levels persisted 24 hours later ( p < 0.01). PAI-1 levels decreased following PVI compared to the baseline levels ( p = 0.02). PAI-1 levels normalized 24 hours after the procedure. DD increased continuously during the procedure with the peak following PVI ( p < 0.01). Higher DD concentrations persisted 24 hours later ( p = 0.02). In a multivariate analysis, total procedure time correlated significantly with the peak vWf and DD concentrations, while total RF energy dose correlated only with peak vWf ( r = 0.82). Time to heparin administration correlated with DD levels prior to the first RF pulse ( r = 0.83, p < 0.01) as well as after PVI ( r = 0.75, p < 0.01). A group of patients heparinized within the first hour of the PVI procedure had normal preablation DD levels and significantly mitigated DD levels following PVI compared to the group of patients heparinized later ( p < 0.01).

CONCLUSIONS

Pulmonary vein ablations cause an increased systemic procoagulant state as reflected by fibrin turnover, fibrinolysis activation and endothelial perturbation. The activation of the coagulation cascade could be decreased by early heparin administration.

Activation of coagulation occurs after electrical cardioversion in patients with chronic atrial fibrillation despite optimal anticoagulation with warfarin

BACKGROUND

There is evidence for the activation of the coagulation system and a hypercoagulable state following cardioversion. The aim of the study was to determine whether electrical cardioversion in patients with chronic atrial fibrillation induced a prothrombotic state despite optimal anticoagulation. We studied the effects of electrical cardioversion on plasma levels of fibrinogen, antithrombin III, protein C and D-dimers.

METHODS

We studied 24 patients with chronic atrial fibrillation who were on optimal anticoagulation and were referred for electrical cardioversion. Samples of venous blood were taken 2 h pre and post cardioversion and 1 month later.

RESULTS

Plasma median concentrations of fibrinogen decreased significantly from 3.8 g/l (interquartile range 3.1-4.2 g/l) before cardioversion to 3.5 g/l (interquartile range 2.9-3.9 g/l) 2 h after cardioversion levels (P=0.004). The fibrinogen levels at 1 month post cardioversion (3.45 g/l, interquartile range 3.1-3.9 g/l) were also significantly lower than baseline (P=0.02). Plasma median levels of antithrombin III fell from 93.5 U/dl (interquartile range 89.3-97.0 U/dl) pre cardioversion to 89.5 U/dl (interquartile range 83.0-93.0 U/dl) 2 h after cardioversion (P=0.001) and returned to normal by 1 month (94.0 U/dl; interquartile range 89.3-98.5 U/dl; P=0.0001). There were no significant changes in plasma median D-dimer or protein C levels at any time.

CONCLUSIONS

We have demonstrated a significant fall in the plasma fibrinogen and antithrombin III levels in patients with chronic atrial fibrillation early after electrical cardioversion, indicating thrombin generation. This study suggests that there are haemostatic changes of thrombogenesis induced by cardioversion despite optimal anticoagulation with warfarin.

Effect of interleukin-6 blockade on tissue factor-induced coagulation in human endotoxemia

OBJECTIVE

Clinical trials show that interleukin (IL)-6 represents a predictive marker in human sepsis. Furthermore, IL-6 has been proposed as a candidate mediator for endotoxin (lipopolysaccharide)-induced coagulation activation: In a primate model, an (alphaIL-6 antibody (alphaIL-6 Ab) almost abolished lipopolysaccharide-induced coagulation activation. Therefore, we wished to determine if an alphaIL-6 Ab (B-E8) may also attenuate lipopolysaccharide-induced activation of coagulation in humans.

DESIGN

The study was a randomized, double blind, placebo-controlled parallel group trial (n = 12 per group).

SETTING

University medical center.

PATIENTS

Healthy volunteers.

INTERVENTIONS

Healthy volunteers were randomized to receive either 80 mg of a monoclonal anti-IL-6 Ab (B-E8) or placebo intravenously before bolus infusion of 2 ng/kg lipopolysaccharide.

MEASUREMENTS AND MAIN RESULTS

B-E8 effectively decreased IL-6 bioactivity as measured by a Bg-bioassay in vitro and concentrations of C reactive protein. However, B-E8 did not decrease lipopolysaccharide-induced tissue factor-messenger RNA transcription or plasma concentrations of downstream coagulation variables (prothrombin fragment 1 + 2, thrombin-antithrombin III complexes, and D-dimer concentrations). Similarly, tumor necrosis factor-alpha concentrations, fibrinolytic activity (plasmin-antiplasmin complexes), endothelial activation (soluble E-selectin), and IL-10 were unaffected.

CONCLUSION

IL-6 does not appear to mediate early-phase lipopolysaccharide-induced coagulation activation in humans.

Activated protein C concentrate reverses purpura fulminans in severe genetic protein C deficiency

Severe genetic protein C deficiency is rare and is associated with severe, often fatal thrombosis. The authors report the use of recombinant activated protein C (APC) to treat an episode of purpura fulminans (PF) in a teenage girl with severe protein C deficiency who had developed anaphylaxis to fresh-frozen plasma that was given in the past to treat recurrent episodes of PF. Concomitant with an infusion of APC, 20 microg/kg/h for 10 hours, a d-dimer level that was markedly positive (6,450 ng/mL) prior to the onset of PF decreased to 847 ng/mL following the APC. The teenager was treated with heparin along with warfarin for four days until the INR was more than 3.5 and the d-dimer level was less than 230 ng/mL. At the end of the APC infusion all skin lesions of PF were resolved. There were no adverse reactions to APC. APC was safe and effective for treatment of PF in severe genetic protein C deficiency.

Fibrinolytic activity and bleeding after cardiac surgery with cardiopulmonary bypass and low-dose aprotinin therapy

Low-dose aprotinin inhibits hyperfibrinolysis in cardiac surgery. However, excessive postoperative bleeding and increased fibrinolysis may occur despite low dose-aprotinin administration. We investigated (i) whether fibrinolytic activity significantly rises under low-dose aprotinin administration, and (ii) whether this is associated with excessive postoperative bleeding (> or = 1000 ml/24 h). In a prospective single-blind trial, 120 consecutive patients were randomized to receive 280 mg aprotinin or no aprotinin before skin incision. D-dimer levels increased significantly to the end of surgery, reaching higher levels in the control group. The risk for excessive bleeding was lower in the aprotinin group (12 versus 37%, = 0.001). Fifteen minutes after heparin reversal, patients were at risk for excessive bleeding, when enhanced fibrinolysis was documented (aprotinin group, D-dimer > or = 1.0 micro g/ml, odds ratio = 9.1, = 0.047; control group, D-dimer > or = 3.0 micro g/ml, odds ratio = 4.6, = 0.014). Ninety-seven per cent of the aprotinin group and 81% of control group patients had no excessive bleeding when the D-dimer plasma level was below these values. We conclude that (i) fibrinolytic activity significantly rises under low-dose aprotinin administration, and (ii) plasma D-dimer levels at end of surgery may help to identify patients who are unlikely to develop excessive postoperative bleeding.

A prospective randomized trial of aspirin-clopidogrel combination therapy and dose-adjusted warfarin on indices of thrombogenesis and platelet activation in atrial fibrillation

OBJECTIVES

This study was designed to investigate whether or not combination aspirin-clopidogrel therapy would reduce markers of thrombogenesis and platelet activation in atrial fibrillation (AF), in a manner similar to warfarin.

BACKGROUND

Dose-adjusted warfarin is beneficial as thromboprophylaxis in AF, but potentially serious side effects and regular monitoring leave room for alternative therapies. METHODS; We randomized 70 patients with nonvalvular AF who were not on any antithrombotic therapy to either dose-adjusted warfarin (international normalized ratio 2 to 3) (Group I) or combination therapy with aspirin 75 mg and clopidogrel 75 mg (Group II). Plasma indices of thrombogenesis (fibrin D-dimer, prothrombin fragment 1+2) and platelet activation (beta-thromboglobulin [TG] and soluble P-selectin) were quantified, along with platelet aggregation responses to standard agonists, at baseline (pretreatment) and at six weeks posttreatment. RESULTS; Pretreatment levels of fibrin D-dimer (p = 0.001), beta-TG (p = 0.01) and soluble P-selectin (p = 0.03) were raised in patients with AF, whereas plasma prothrombin fragment 1+2 levels and platelet aggregation were not significantly different compared with controls. Dose-adjusted warfarin reduced plasma levels of fibrin D-dimer, prothrombin fragment 1+2 and beta-thromboglobulin levels at six weeks (all p < 0.001), enhanced plasma levels of soluble P-selectin (p < 0.001) and had no significant effect on platelet aggregation. Aspirin-clopidogrel combination therapy made no difference to the plasma markers of thrombogenesis or platelet activation (all p = NS), but the platelet aggregation responses to adenosine diphosphate (p < 0.001) and epinephrine (p = 0.02) were decreased.

CONCLUSIONS

Aspirin-clopidogrel combination therapy failed to reduce plasma indices of thrombogenesis and platelet activation in AF, although some aspects of ex vivo platelet aggregation were altered. Anticoagulation with warfarin may be superior to combination aspirin-clopidogrel therapy as thromboprophylaxis in AF.

Effects of simvastatin on high-sensitivity C-reactive protein and serum albumin in hemodialysis patients

A 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor is recommended in hemodialysis (HD) patients with hypercholesterolemia to improve their lipid profiles. We evaluated effects of simvastatin on markers for inflammation, oxidative stress, and coagulation in HD patients. Sixty-two maintenance HD patients with serum cholesterol levels of 200 mg/dL or greater were randomly assigned to the treatment group (n = 31; 8 men, 23 women; age, 63 +/- 11 years) and administered simvastatin, 20 mg/d, for 8 weeks or to the control group (n = 31; 10 men, 21 women; age, 60 +/- 12 years). We measured cholesterol, albumin, high-sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA; an index of lipid peroxidation), and D-dimer (a marker of intravascular coagulation) in blood at baseline and again at 8 weeks. Fifty-eight of 62 patients completed the study. In the control group, total cholesterol, serum albumin, hs-CRP, MDA, and D-dimer levels did not change. In the treatment group, simvastatin administration for 8 weeks significantly reduced total cholesterol levels from 232 +/- 25 to 165 +/- 39 mg/dL (P < 0.001) and hs-CRP levels from a median of 0.23 mg/dL (range, 0.05 to 1.63 mg/dL) to 0.12 mg/dL (range, <0.006 to 1.45 mg/dL; P < 0.01), whereas it increased serum albumin levels from 3.4 +/- 0.3 to 3.6 +/- 0.4 g/dL (P < 0.001). Administration of simvastatin did not affect MDA and D-dimer levels. These results suggest that in addition to the lipid-lowering effect, simvastatin had an antiinflammatory effect in HD patients. Considering that atherosclerosis is inflammation of the vascular wall, simvastatin may have a beneficial effect on cardiovascular disease, in part because it alleviates inflammation.

Anti-c5a ameliorates coagulation/fibrinolytic protein changes in a rat model of sepsis

Sepsis and trauma are the two most common causes of disseminated intravascular coagulation and multiple organ dysfunction syndrome. Both disseminated intravascular coagulation and the systemic inflammatory response syndrome often lead to multiple organ dysfunction syndrome. The current studies have evaluated the relationship between the anaphylatoxin, C5a, and changes in the coagulation/fibrinolytic systems during the cecal ligation and puncture (CLP) model of sepsis in rats. CLP animals treated with anti-C5a had a much improved number of survivors (63%) compared to rats treated with pre-immune IgG (31%). In CLP rats treated with pre-immune IgG there was clearly increased procoagulant activity with prolongation of the activated partial thromboplastin time and prothrombin time, reduced platelet counts, and increased levels of plasma fibrinogen. Evidence for thrombin formation was indicated by early consumption of factor VII:C, subsequent consumption of factors XI:C and IX:C and anti-thrombin and increased levels of the thrombin-anti-thrombin complex and D-dimer. Limited activation of fibrinolysis was indicated by reduced plasma levels of plasminogen and increased levels of tissue plasminogen activator and plasminogen activator inhibitor. Most of these parameters were reversed in CLP rats that had been treated with anti-C5a. Production of C5a during sepsis may directly or indirectly cause hemostatic defects that can be reduced by blockade of C5a.

Valsartan improves fibrinolytic balance in atherosclerotic rabbits

OBJECTIVES

To examine the long-term effects of the angiotensin type I (AT1) receptor antagonist, valsartan, on fibrinolytic balance, coagulation parameters, endothelial function and structural alterations in atherosclerotic rabbits.

METHODS

Animals were submitted to a 1% cholesterol-enriched diet for 10 weeks. Half of the animals were treated with valsartan (3 or 10 mg/kg per day). Systolic arterial pressure was directly measured in awake rabbits. Tissue plasminogen activator (t-PA) and tissue plasminogen activator inhibitor (PAI-1) activities were measured. Plasma concentrations of cholesterol, D-dimer, factor VIII and fibrinogen, as well as thrombin time, were also determined. Responses to acetylcholine, sodium nitroprusside and angiotensin II were evaluated in aortic rings. Morphometric analysis of aortic segments was also performed to calculate atherosclerotic lesion.

RESULTS

Cholesterol-fed rabbits presented systolic arterial pressure levels comparable to controls. These animals presented aortic atherosclerotic lesions. Treatment with valsartan did not alter plasma cholesterol levels or arterial pressure in any group. Acetylcholine-induced relaxations and D-dimer and t-PA activity were lower (P < 0.05) in atherosclerotic than in normal rabbits. In contrast, PAI-1 activity was higher (P < 0.05) in atherosclerotic rabbits than in controls. Valsartan increased (P < 0.05) acetylcholine-induced relaxations, D-dimer concentration and t-PA activity, and reduced intimal thickening and PAI-1 activity in cholesterol-fed rabbits. Fibrinogen concentrations and factor VIII concentrations were lower (P < 0.05) and thrombin time was higher (P < 0.05) in atherosclerotic rabbits compared to controls. Valsartan did not affect factor VIII in any group, but reduced fibrinogen levels only in hypercholesterolemic rabbits. Valsartan 10 mg/kg per day reduced (P < 0.05) thrombin time in cholesterol-fed rabbits.

CONCLUSIONS

Impairment of fibrinolytic balance, associated with atherosclerosis in rabbits, appears to be related with angiotensin II via AT1receptors. The beneficial effect of valsartan on fibrinolysis seems to be related to the concomitant amelioration of endothelial dysfunction and reduction of intimal thickening, further supporting the importance of the blockade of angiotensin II actions to prevent thrombotic alterations associated with atherosclerosis.

Simplified citrate anticoagulation for high-flux hemodialysis

In a randomized crossover trial, we compared a simple citrate anticoagulation protocol for high-flux hemodialysis with standard anticoagulation by low-molecular-weight heparin (dalteparin). Primary end points were urea reduction rate (URR), Kt/V, and control of electrolyte and acid-base homeostasis. Secondary end points were bleeding time at vascular puncture sites and markers of activation of platelets, coagulation, and fibrinolysis. Solute removal during citrate dialysis was excellent (URR, 0.71 +/- 0.06; Kt/V, 1.55 +/- 0.3) and similar to results of conventional bicarbonate hemodialysis anticoagulation with dalteparin (URR, 0.72 +/- 0.04; Kt/V, 1.56 +/- 0.2). Electrolyte control was effective with both anticoagulation regimens, and total and ionized calcium, sodium, potassium, and phosphate concentrations at the end of dialysis did not differ. Alkalemia was less frequent after citrate than conventional dialysis (pH 7.5 in 25% versus 62% of patients; mean pH at end of dialysis, 7.46 +/- 0.06 versus 7.51 +/- 0.07; P < 0.01). Bleeding time at puncture sites was shorter by 30% after citrate compared with dalteparin anticoagulation (5.43 +/- 2.80 versus 7.86 +/- 2.93 minutes; P < 0.001). Activation of platelets, coagulation, and fibrinolysis was modest for both treatments and occurred mainly within the dialyzer during dalteparin treatment and in the vascular-access region during citrate anticoagulation. Citrate-related adverse events were not observed. We conclude that citrate anticoagulation for high-flux hemodialysis is feasible and safe using a simple infusion protocol.

Effects of fixed low-dose warfarin on hemostatic factors in continuous ambulatory peritoneal dialysis patients

Increased coagulation factors found in dialysis patients may explain in part the high prevalence of thrombotic cardiovascular disease. Several studies showed low-dose warfarin is effective in decreasing coagulation factors and preventing thrombosis without increasing the risk of bleeding. To evaluate the effects of fixed low-dose warfarin therapy on thrombogenesis in continuous ambulatory peritoneal dialysis (CAPD) patients, 76 CAPD patients were assigned randomly to treatment and disease control groups. The treatment group received 2 mg of warfarin daily for 12 months. International normalized ratio (INR) of the prothrombin time and plasma levels of factor VII, D-dimer, von Willebrand factor (vWF), and plasminogen activator inhibitor-1 (PAI-1) were measured before and 3, 6, and 12 months after the start of medication. The same parameters were measured in 30 healthy volunteers at the beginning of the study and in the disease control group during the study period. Of 76 patients, 60 completed the study. Deaths from atherosclerotic cardiovascular disease (cerebral infarction or acute myocardial infarction) occurred in 1 patient in the treatment group (n = 29) and 3 in the disease control group (n = 31), which was not statistically significant. No major bleeding occurred during the study period. With administration of warfarin, there was a small increase in INR in the treatment group. CAPD patients at baseline had significantly higher plasma factor VII, D-dimer, vWF, and PAI-1 levels than normal controls. Warfarin therapy lowered plasma factor VII and D-dimer levels. No change was seen in vWF and PAI-1 levels. In the disease control group, these hemostatic factors showed no change during the study period. There was a negative correlation between serum albumin and INR in the treatment group during the study period. Fixed low-dose warfarin was effective in partially reversing the thrombogenic coagulation profile in CAPD patients without a big increase in the risk of bleeding.

PLATSAK, a potent antithrombotic and fibrinolytic protein, inhibits arterial and venous thrombosis in a baboon model

Antiplatelet-antithrombin-staphylokinase (PLATSAK) is a chimeric protein that was recombinantly produced in Escherichia coli cells. The protein was designed to target haemostasis at three different levels. It consists of staphylokinase for activation of fibrinolyis, the Arg-Gly-Asp sequence for the prevention of platelet aggregation, and an antithrombotic peptide for the inhibition of thrombin. The in vivo activity of PLATSAK was evaluated by assessing its effect on platelet deposition in a baboon model of arterial and venous thrombosis. Dacron vascular graft segments and expansion chambers, inserted as extensions into permanent femoral arteriovenous shunts, were used to simulate arterial and venous thrombosis, respectively. PLATSAK (3.68 mg/kg) was administered as a bolus 10 minutes before placement of the thrombogenic devices. Platelet deposition onto the graft surface and in the expansion chamber was imaged in real time with a scintillation camera as the deposition of 111In-labeled platelets. After 2 hours, platelet deposition in the graft segments and expansion chambers was inhibited by 50% and 85%, respectively, when compared to control studies. The activated partial thromboplastin time was lengthened to greater than 120 seconds. Interestingly, the level of fibrinogen degradation products in plasma did not increase after administration of PLATSAK. These results demonstrate that PLATSAK effectively inhibited platelet deposition in both arterial- and venous-type thrombosis in an animal model.

Short-chain fatty acid enemas stimulate plasminogen activator inhibitor-1 after abdominal aortic graft surgery: a double-blinded, placebo-controlled study

Colonic ischaemia may complicate aortic graft surgery with high mortality from associated colonic necrosis. Loss of the mucosal barrier function due to ischaemia may promote translocation of endotoxins with secondary systemic disseminated coagulation leading to multiple organ failure. Short-chain fatty acids (SCFAs) stimulate the microcirculation in the human rectum. The aim of this study was to investigate whether SCFA enemas influence systemic endotoxinaemia and fibrinolytic activity during and after elective aortic graft surgery for arteriosclerosis. Thirty-two patients were randomized to SCFA or placebo enemas twice daily from the day before surgery to 7 days after. Blood samples for endotoxin, plasminogen activator inhibitor-1 (PAI-1) activity, tissue-type plasminogen activator (t-PA) antigen, and cross-linked fibrin degradation products (XL-FDP) were drawn before, during, and 7 days after surgery. Four patients, two in each treatment group, developed postoperative endotoxinaemia. PAI-1 was significantly higher on days 2 and 4 in SCFA-treated patients, whereas t-PA was comparable Petween the groups. During the postoperative course, a progressive and near-identical XL-FDP increase was found in the two groups. In elective aortic graft surgery for arteriosclerosis, SCFA enemas likely stimulate systemic PAI-1 activity by promoting colonic tissue reperfusion following aortic unclamping. Endotoxinaemia and fibrinolytic shutdown are uncommon findings.

Relationship of cardiac troponin T and procoagulant activity in unstable angina

OBJECTIVE

The present study sought to determine the incidence of increased procoagulant activity in patients with unstable angina (UAP), and to evaluate the relationship between cardiac troponin T (cTnT) and molecular markers of hemostatic activation. Method. We studied 44 patients with UAP further classified by plasma cTnT levels. All patients received an antithrombotic therapy consisting of therapeutic doses of unfractionated heparin and acetylsalicylic acid. Quantitative levels of cTnT and plasma concentrations of fibrin monomers (FM), prothrombin fragments F1+2, thrombin antithrombin III complexes (TAT), plasminogen and alpha2-antiplasmin were sampled serially within the first 48 h.

RESULTS

Increased plasma concentrations of FM were detected in 45.5% of patients and were more frequently present among those with cTnT concentrations > or =0.1 ng/ml (13 of 18 vs 7 of 26 patients, p = 0.003). In these patients, mean plasma concentrations of FM were significantly higher than in patients with cTnT <0.1 ng/ml (7.93 +/- 2.3 vs 3.12 +/- 0.6 microg/ml, p = 0.02). There was a close relationship between plasma levels of cTnT and FM (r = 0.74, p <0.004), prothrombin fragments F1+2 (r = 0.71, p = 0.046) and a trend to significance was noted for TAT (r = 0.42, p = 0.055). No significant correlation was observed with markers of the fibrinolytic system (plasminogen and alpha2-anti-plasmin). Plasma levels of cTnT > or =0.1 ng/ml identified a concomitant increase of hemostatic markers with a sensitivity, specificity and positive predictive value of 65, 79, and 72% for FM, 63, 76, and 67% for prothrombin fragments F1+2, and 58, 66, and 39% for TAT, respectively.

CONCLUSIONS

In patients with UAP, cTnT identifies patients with increased procoagulant activity and is closely related to plasma levels of molecular markers of hemostatic activation. Therefore, cTnT alone or in combination with one of these markers may be helpful to identify patients requiring more potent antithrombin or antiplatelet therapy.

Possible mechanisms through which dietary pectin influences fibrin network architecture in hypercholesterolaemic subjects

It is suspected that not only fibrinogen concentration but also the quality of fibrin networks may contribute to cardiovascular risk. Evidence is accumulating that a "prudent" diet may protect against diseases associated with raised clotting factors. The effect of diet on fibrinogen is, however, still controversial. In a previous study performed in our laboratory, it was shown that dietary pectin influences fibrin network architecture in hypercholesterolaemic men without causing any changes in fibrinogen concentration. To elucidate the possible mechanisms, it was necessary to study the possibility that pectin may itself have indirect effects on fibrin network architecture. Pectin is fermented in the gastrointestinal tract to acetate, propionate, and butyrate. In humans, only acetate reaches the circulation beyond the liver. This investigation primarily examined the possibility that pectin may, through acetate, influence fibrin network architecture in vivo. The effects of pectin and acetate supplementation in hypercholesterolaemic subjects were compared. Furthermore, this study also aimed at describing the possible in vitro effects of acetate on fibrin network architecture. Two groups of 10 male hyperlipidaemic volunteers each received a pectin (15 g/day) or acetate (6.8 g/day) supplement for 4 weeks. Acetate supplementation did not cause a significant change in plasma fibrinogen levels. As in the pectin group, significant differences were found in the characteristics of fibrin networks developed in plasma after 4 weeks of acetate supplementation. Fibrin networks were more permeable (from 213+/-76 to 307+/-81 x 10(11) cm2), had lower tensile strength (from 23+/-3 to 32+/-9% compaction), and were more lyseable (from 252+/-11 to 130+/-15 minutes). These results strongly suggest that the effect of pectin on network architecture could partially be mediated by acetate. Progressive amounts of acetate were used in vitro to investigate the possibility that acetate may be directly responsible for changes that occurred in fibrin network architecture in the plasma medium. Results indicated that acetate influenced fibrin network architecture directly. From the results, it seems highly possible that acetate may be responsible in part for the beneficial effects of pectin supplementation in vivo. It is evident that pectin or acetate supplementation can be useful during the treatment or prevention of some clinical manifestations, especially those associated with raised total cholesterol and possibly also plasma fibrinogen.

Effects on hemostasis after two-year use of low dose combined oral contraceptives with gestodene or levonorgestrel

We studied 67 healthy women who were randomly allocated to receive third generation gestodene (Gynera) or second generation levonorgestrel (Microgynon 30) combination of low-dose estrogen oral contraceptives (OCs) for their hemostatic effects over 2 years. Hemostatic changes were apparent within 3 months of OC use. Hematocrit (Hct) was not affected, but hemoglobin (Hb) concentration decreased by 18 months. Shortened prothrombin time (PT) and activated plasma thromboplastin time (APTT) were associated with elevated fibrinogen within the 12-month use of both OCs. Factor VII was reduced only in Micro 30 during the 18 months of use. Enhanced thrombin-antithrombin (TAT)-complex level was seen at 18 months of Gynera use. Prothrombin fragment1+2 (F1+2) rise was seen at 3 months with Micro 30. Reduced antithrombin III (ATIII) activity was seen at 18 months with Gynera and at 24 months with Micro 30. Increased protein C activity was seen at 3 months and reduced protein S occurred at 18 months of Gynera use. Tissue plasminogen activator (t-PA) activity was enhanced for 6 months in both OCs with raised D-dimer levels for 12 months with Gynera and 6 months with Micro 30. Decreased t-PA antigen was seen at 18 months and decreased urokinaselike plasminogen activator (u-PA) antigen occurred throughout the 24 months of both OCs use. Enhanced u-PA activity was only seen in Gynera users. Elevated plasminogen levels were apparent throughout both OCs use. PAI-1 levels were significantly decreased with Micro 30. With Gynera, the decreased PAI-1 activity was seen only at 18 months and PAI-1 antigen at 12 months. No change in platelets and von Willebrand factor (vWF) were seen in long-term OC use except that beta-thromboglobulin (beta-TG) showed decreased trends reaching statistical significance by 18 and 24 months of Micro 30 use and by 24 months of Gynera use. A further significant decrease in beta-TG, u-PA antigen, ATIII, and protein S levels were seen 3 months after pill stoppage compared with pretreatment levels. Activated protein C resistance (APCR) was negative in all subjects before and during OC use. The study indicated dynamic balance between coagulation and fibrinolysis with no endothelial activation. However, because some hemostatic markers showed wide fluctuations during OC use, a longer term study is warranted to investigate any adverse hemostatic changes that might enhance the risks of venous thromboembolism in Asian subjects known to be less prone to thrombosis.

Alterations in fibrin detected in coronary sinus blood after heparin and coronary angiography with a nonionic contrast agent (iohexol)

Although heparin and some radiographic contrast agents inhibit coagulation, thrombi can still form in their presence. The chemical environment in which a thrombus forms affects fibrin structure that may alter the ability of the thrombus to be lysed. Therefore, we assessed changes in fibrin structure in 13 patients referred for coronary angiography. Blood was obtained from the femoral vein, femoral artery, ascending aorta, left main coronary artery (LMCA), and coronary sinus (CS) before, during, and after coronary angiography was performed with iohexol. The number of fibrin monomers per fiber cross section was determined by turbidity measurements of fibrin gels formed from plasma samples. At baseline there was no difference in the number of fibrin monomers per fiber cross section in plasma gels generated from the different sampling sites. After iohexol administration, there was a significant decrease in the number of fibrin monomers per fiber cross section at the sampling sites ranging from - 13% to -25% compared with the respective baseline values with the largest change in the LMCA CS (51+/-16 to 38+/-15, p <0.025). Transcardiac (LM - CS value) changes in the number of fibrin monomers per fiber cross section were dependent on the timing of the sample collection in the CS. In 7 patients, the CS sample was collected approximately 2 minutes after injection of contrast material and there was no transcardiac difference. When the CS sample was obtained during contrast injection (n=6) a large transcardiac change occurred (44+/-10 to 32+/-14, p=0.01). These data show transient changes in fibrin structure during coronary angiography with iohexol. The thinner fibers formed in the presence of iohexol were more resistant to fibrinolysis.

Aprotinin in pediatric cardiac operations: a benefit in complex malformations and with high-dose regimen only

BACKGROUND

The benefits and the current indications of aprotinin in congenital operations are not well defined. At present there are only a few studies available that have investigated a small number of patients in several heterogeneous groups of malformations.

METHODS

We investigated efficacy and safety of aprotinin in three groups of children < 15 kg, presenting with isolated ventricular septum defect (n = 60), tetralogy of Fallot (n = 52), and transposition of the great arteries (n = 56). Low-dose aprotinin regimen A1 (500,000 KIU in pump prime only) and high-dose aprotinin A2 (50,000 KIU/kg during induction of anesthesia, 50,000 KIU/kg in pump prime, and 20,000 KIU/h continuous infusion) were compared to a control group A0 (without aprotinin) regarding perioperative blood loss, transfusion requirements, and effects on the coagulation system.

RESULTS

The most common coagulation tests of aprotinin-treated patients and the platelet numbers were comparable with those of control patients preoperatively and 15 minutes after protamine administration. A significant dose-dependent reduction in fibrin-fibrinogen split products was observed at the end of cardiopulmonary bypass in the majority of aprotinin-treated patients with transposition. In patients with ventricular septum defect and Fallot, no significant difference in blood loss and transfusion requirements could be observed between patients with or without aprotinin and no difference was observed between low- and high-dose regimen. In transposition of the great arteries, high-dose aprotinin led to significant reduction of blood loss (p = 0.02) and postoperative blood transfusion (p = 0.003). Severe side effects as a result of administration of aprotinin were not observed.

CONCLUSIONS

High-dose aprotinin reduces blood loss and transfusion requirement only in complex congenital cardiac operations; therefore aprotinin cannot be recommended as a blood conservation agent in routine pediatric operations.

Digestion of 125I-labelled plasmin-derived fibrin degradation products by neutrophil lysosomal enzymes

The cellular components of the blood, which become associated with fibrin through specific cellular adhesive processes, play a significant role in the breakdown of fibrin. Fibrinolysis by neutrophil elastase and cathepsin G occurs in a manner distinct from that produced by plasmin. This study demonstrates that neutrophil lysosomal enzyme activity further degrades the end products of plasmic fibrin degradation into low-molecular-weight material, followed by reassembly of higher-molecular-weight products in a process dependent on calcium and factor XIII. Although one of the reformed products has a similar molecular weight to D-dimer and is recognized by a monoclonal antibody raised against D-dimer, its isoelectric point indicates it to be distinctly different from plasmin-derived D-dimer. Processing of the end products of plasmic fibrin degradation by neutrophils may have the potential for modulating the immune response as well as compromising the predictive value of tests measuring D-dimer.

Homozygous type I plasminogen deficiency

Homozygous type I plasminogen (Plg) deficiency has not been described in human subjects so far. Ligneous conjunctivitis is a rare and unusual form of chronic pseudomembranous conjunctivitis of unknown etiology. Here we report for the first time on homozygous type I Plg deficiency in three unrelated female patients who suffered from ligneous conjunctivitis and additional pseudomembranous lesions of other mucous membranes. The disease is caused by massive fibrin depositions within the "extravascular space" of mucous membranes because of absent clearance by plasmin. Infusions of albumin, fresh frozen plasma, or Lys-plasminogen (Lys-Plg) into two of the three patients revealed normal Plg activation capacity in these patients. The absence of fibrinolytic activity could therefore be shown to be due to Plg deficiency. Similar studies in the third patient have not been completed. In the two patients studied so far, infusions of Lys-Plg resulted in prompt and adequate Plg recovery with a short half-life and high amounts of plasmin-antiplasmin complexes and D-dimer. One patient additionally revealed an inherited partial factor XII deficiency. Functionally, this factor XII deficiency did not interfere with Plg activation. However, there may be a pathway of Plg activation in this patient via the prekallikrein C1-INH system.

Hemostatic parameters in sepsis patients treated with anti-TNF alpha-monoclonal antibodies

Tumor necrosis factor-alpha (TNF alpha) is a central mediator in the pathogenesis of sepsis. It also interferes with the hemostatic system and exerts and a net procoagulant effect. Since TNF alpha may contribute to thrombotic complications in sepsis patients, we determined markers of thrombin activation, parameters of the fibrinolytic system (D-dimer, tissue plasminogen activator antigen (tPA) urinary type plasminogen activator antigen (uPA), plasminogen activator inhibitor antigen (PAI-1) and von Willebrand factor antigen (vWF) in 30 patients with sepsis or septic shock. All patients were treated with standard therapy, but 14 patients were treated additionally with an anti-TNF alpha monoclonal antibody (MAK 195F); 16 patients served as historical controls. No significant effect of the antibody on the parameters of the hemostatic system could be determined. Our data speak against a modulation of coagulation or the fibrinolytic system by the monoclonal anti-TNF alpha antibody MAK 195F in this cohort of sepsis patients.

Acetylsalicylic acid may protect the patient by increasing fibrin gel porosity. Is withdrawing of treatment harmful to the patient?

The effect of acetylsalicylic acid in preventing cardiovascular complications is ascribed to acetylation of the enzyme cyclo-oxygenase thereby inhibiting prostaglandin synthesis. Acetylsalicylic acid, however, also acetylates fibrinogen. In the present pilot study, we investigated the permeability, i.e. porosity, of the fibrin gel in male patients with stable angina pectoris treated with this drug before and at 1 and 2 weeks after withdrawal. Ten patients were treated with 75 mg and eight with 160 mg. The results were compared to those in seven untreated healthy controls. Bleeding times were longer during treatment and were reduced after withdrawal indicating patient compliance. Fibrin gels were more porous during treatment although there were large inter-individual variations in porosity. One week after withdrawal, the porosity was reduced by 30 41%, i.e. the network became tighter (75 mg group P = 0.001; 160 mg group P = 0.002). The tightness was more pronounced after withdrawal than in the untreated controls. In conclusion, the protective effect of acetylsalicylic acid may be ascribed to its effect not only on platelets but also on fibrinogen. The withdrawal of acetylsalicylic acid may clause a markedly reduced fibrin gel porosity that we assume is disadvantageous in patients with cardiovascular disease.

Increased plasma concentration of fibrin monomer in acute myocardial infarction with early reperfusion

OBJECTIVE

To assess whether plasma fibrin monomer (FM) concentration, a marker of thrombin activity, is increased in the first hours after acute coronary occlusion and whether there are differences between patients with and without early reperfusion.

DESIGN

Thirty-five consecutive patients with acute myocardial infarction (AMI) and early coronary angiography were studied prospectively.

METHODS

Plasma FM samples taken on admission (< 6 h after onset of chest pain) and 6-14 h after onset of chest pain were analysed using a specific enzyme immunoassay. All of the patients were anticoagulated with heparin intravenously.

RESULTS

Of the 35 patients, 28 had angiographically documented reperfusion within the first 6 h, whereas seven patients had no early reperfusion. FM concentrations were measured in the reference range (< or = 3.6 mg/l) within the first 6 h in 32 of the 35 patients. At 6-14 h FM concentrations were elevated in the reperfusion group (median 4.56 mg/l), but not in the group without reperfusion (median 1.6 mg/l, P = 0.0063). Using a threshold value of 3.0 mg/l, sensitivity and specificity of FM for the non-invasive recognition of early reperfusion were 78 and 83%, respectively. The specificity was similar to that for troponin T and higher than the creatinine kinase MB specificity.

CONCLUSIONS

FM plasma concentrations are elevated in patients with AMI and early reperfusion. With a single blood sample 6-14 h after onset of chest pain, FM analysis is useful for the non-invasive detection of early reperfusion after AMI.

Streptokinase inhibits pulmonary tumor seeding in an animal experimental model

One aspect of the metastatic process involves entrapment of tumor cells within the microcirculation of organs in a "fibrin-platelet mesh." We postulate that destruction of this mesh by fibrinolysis might discourage tumor seeding, thereby inhibiting metastasis. To study this hypothesis, the effect of intravenous streptokinase on pulmonary tumor seeding was examined in a rodent model. In vitro experiments demonstrated that streptokinase had no cytotoxic or cytostatic effect on the Mtln3 cell line. Pharmacokinetic studies showed that at 30,000 U/kg, streptokinase caused systemic fibrinolysis in the Fischer rat, as demonstrated by the thrombin time and fibrin plate lysis assay. Streptokinase administered at this dose, 30 min after tumor cell injection, caused a significant decrease in pulmonary tumor seeding (median 23.0 in the streptokinase-treated group vs. 67.5 in untreated controls, P < 0.0001, Mann-Whitney U-test). Analysis of fibrin degradation products in the streptokinase-treated group suggested that this effect might be secondary to fibrinolysis. The implications of these findings are discussed.

[An analysis of a disorder in the fibrin-forming phase in virtually healthy middle-aged and elderly subjects by using the ancistron test]

Damages in the fibrin-formation phase initiated by activation of the blood coagulation system and fibrinolysis and promoted by interaction between fibrinogen and its derivatives (dissolved fibrinogen, products of fibrin and fibrinogen lysis) and by the presence of various blood coagulation inhibitors were found in 34% of practically sound old people and in 47% of people of senile age. It is shown very significant to apply the "ancistrone time" test developed on the basis of enzyme ancistrone-H isolated from the venom of snake Agkistrodon halys halys for estimating the fibrin-formation phase both on the model system and in practically sound people of old and senile age. The ancistrone test permits rapidly (for 30-60s) obtaining qualitative and quantitative characteristic of the fibrinogen level in the blood plasma, of the products of fibrin and fibrinogen lysis, of the blood coagulation inhibitors.

Influence of heparin on fibrinogen and D-dimer plasma levels in acute myocardial infarction treated with streptokinase

The purpose of this study was to investigate whether, to what extent, and through which mechanisms intravenous heparin, administered before and after streptokinase, affects the plasma levels of D-dimer and fibrinogen in myocardial infarction. Data concerning mortality and incidence of coronary recanalization in patients receiving heparin and thrombolytic therapy after acute myocardial infarction are controversial; furthermore, the mechanisms through which heparin acts in combination with thrombolytic therapy are unclear. Thirty-eight patients with acute myocardial infarction treated with streptokinase were considered. Nineteen of them received, immediately before the beginning of thrombolytic treatment, a bolus of heparin (100 U.kg-1 intravenously) and, 2 h later, intravenous heparin in doses raising the partial thromboplastin time to 2-2.5 times the normal value (Group 1); the remaining 19 did not receive anticoagulant treatment (Group 2). Multiple determinations of plasma D-dimer and fibrinogen levels were obtained in all patients before, and in the seven days following thrombolytic treatment. Six hours after streptokinase, fibrinogen decreased from 304 +/- 34 to 61 +/- 34 mg.dl-1 in Group 1 and from 312 +/- 29 to 38 +/- 21 mg.dl-1 in Group 2 (P < 0.02 versus Group 1). The same difference between groups persisted at the 12th and at the 18th hour. D-dimer values, from 0.5 +/- 0.1 microgram.dl-1 in Group 1 and 0.4 +/- 0.1 microgram.dl-1 in Group 2, increased at the 1st hour to 37.2 +/- 36.5 micrograms.dl-1 and 52.2 +/- 39.8 micrograms.dl-1, respectively. A peak value was reached in both groups at the 6th hour, which was followed by a slow decrease.(ABSTRACT TRUNCATED AT 250 WORDS)

Aprotinin reduces cardiopulmonary bypass-induced blood loss and inhibits fibrinolysis without influencing platelets

Cardiopulmonary bypass (CPB) induces a bleeding defect which leads to enhanced blood loss. A double-blind study was carried out comparing aprotinin with placebo in patients undergoing re-operation for heart valve replacement. The results confirm that aprotinin is effective at reducing such loss. In the placebo treated group, significant increases were observed, during CPB, in the plasma concentrations of fibrinolytic activity, tissue plasminogen activator antigen, D-dimer, and beta-thromboglobulin. Platelet counts fell within 5-10 min of the patients going onto CPB, but this could be accounted for by the dilutional effect of the extracorporeal circuit. Inhibition of responsiveness of platelets, as judged by aggregometry, was significant only at the end of bypass when collagen was the agonist and after protamine reversal when ristocetin was the agonist. CPB did not enhance the release, into the circulation, of glycocalicin (a proteolytic fragment of glycoprotein Ib). In the aprotinin-treated group, the formation of fibrin degradation products as measured by D-dimer was inhibited. However, aprotinin did not influence the change in platelet count, suppress beta-thromboglobulin release from platelets, prevent the inhibition of platelet function or influence the concentration of plasma glycocalicin during the study period. These observations confirm that CPB leads to a fibrinolytic state and less responsive platelets. This study also indicates that aprotinin-induced reduction in blood loss is associated with inhibition of plasmin-mediated fibrin digestion and that the mechanism by which aprotinin reduces blood loss is not via protection of platelets during CPB.

Hemostatic activation during cardiopulmonary bypass with different aprotinin dosages in pediatric patients having cardiac operations

The effect of high-dose aprotinin treatment on hemostatic activation during cardiopulmonary bypass in pediatric patients having cardiac operations was investigated. Sixty patients weighing less than 10 kg undergoing cardiac operations for different types of congenital heart diseases were studied: 20 patients were treated with aprotinin 2 x 15,000 KIU/kg, 20 patients with 2 x 30,000 KIU/kg, and 20 patients without aprotinin treatment served as the control group. Different split products of fibrinogen and/or fibrin and the fibrinolytic activity on fibrin plates were measured to assess fibrinolytic activation. F1/F2 prothrombin fragments, thrombin-antithrombin III-complex, and fibrin monomers were measured to estimate thrombin activation. There was a significant dose-dependent reduction in fibrin-fibrinogen split product formation during cardiopulmonary bypass: In the high-dose aprotinin group the concentration of the split products at the end of bypass was 1.5 +/- 0.6 micrograms/ml, compared with 3.4 +/- 3.0 micrograms/ml in the low-dose aprotinin group and 6.7 +/- 3.5 micrograms/ml in the control group (p < 00.5). Fibrinolytic activation on fibrin plates was also significantly reduced by aprotinin. Fibrin monomer formation was significantly diminished at the end of cardiopulmonary bypass in the high-dose group: 9.2 +/- 5.2 micrograms/ml compared with 21.6 +/- 14 micrograms/ml in the control group (p < 00.5). Elastase in complex with alpha 1-protease inhibitor at the end of bypass was increased to the same amount in the three groups: 784 +/- 278 ng/mL (control group), 693 +/- 189 ng/ml (low-dose aprotinin), and 719 +/- 270 ng/mL (high dose aprotinin) (no significant difference). Blood loss 6 hours postoperatively was significantly (p < 00.5) less in the high-dose group (99 +/- 32 ml/m2) than in the control group (164 +/- 87 ml/m2; low-dose group: 160 +/- 106 ml/m2). These observations suggest an attenuation of hemostatic activation during cardiopulmonary bypass with less plasmin formation and, because of inhibition of contact activation, less thrombin generation with aprotinin treatment. Thus the thrombotic-thrombolytic equilibrium is kept more balanced after cardiopulmonary bypass. High-dose aprotinin treatment is recommended for pediatric patients undergoing cardiac operations.

[The thromboplastic activity of normal and tumorous human tissues]

The study was made of thromboplastic activity of normal, pathological and tumor human tissues using a hemocoagulatory test-system specifically sensitive to apoprotein III-containing membrane structures. It is established that thromboplastic activity of membrane fragments can be inhibited by native cell components. Blood coagulation and fibrin deposition in tissues can go without cell damaging under initiation by increased permeability of vascular walls and plasma contact with surface of the cells located extravascularly.

[The use of picotamide in nephropathy with mesangial IgA deposits. The effect on thromboxane generation]

IgA nephropathy (Berger's disease) is one of the commonest forms of glomerular disease, not rarely progressing to renal failure. Hemostatic system activation may play a role in the development of glomerular injury. In a series of 12 adult patients affected with IgA nephropathy we have observed increased plasma levels of D-dimer, a stable end-product of cross-linked fibrin degradation that is considered a reliable index of blood clotting activation, as well as "in vitro" raised generation of thromboxane, the main platelet product of arachidonic acid metabolism that seems to play an important role in glomerulosclerosis. Picotamide, a novel antiplatelet drug acting as thromboxane synthase inhibitor as well as thromboxane receptor antagonist, administered for 8-12 weeks, was effective in reducing thromboxane generation. We conclude that picotamide may be useful in the management of glomerular nephropathy.

Hemorrhagic events during therapy with recombinant tissue-type plasminogen activator, heparin, and aspirin for acute myocardial infarction. Results of the Thrombolysis in Myocardial Infarction (TIMI), Phase II Trial

OBJECTIVES

To assess the effects of invasive procedures, hemostatic and clinical variables, the timing of beta-blocker therapy, and the doses of recombinant plasminogen activator (rt-PA) on hemorrhagic events.

DESIGN

A multicenter, randomized, controlled trial.

SETTING

Hospitals participating in the Thrombolysis in Myocardial Infarction, Phase II trial (TIMI II).

INTERVENTIONS

Patients received rt-PA, heparin, and aspirin. The total dose of rt-PA was 150 mg for the first 520 patients and 100 mg for the remaining 2819 patients. Patients were randomly assigned to an invasive strategy (coronary arteriography with percutaneous angioplasty [if feasible] done routinely 18 to 48 hours after the start of thrombolytic therapy) or to a conservative strategy (coronary arteriography done for recurrent spontaneous or exercise-induced ischemia). Eligible patients were also randomly assigned to either immediate intravenous or deferred beta-blocker therapy.

MEASUREMENTS

Patients were monitored for hemorrhagic events during hospitalization.

MAIN RESULTS

In patients on the 100-mg rt-PA regimen, major and minor hemorrhagic events were more common among those assigned to the invasive than among those assigned to the conservative strategy (18.5% versus 12.8%, P less than 0.001). Major or minor hemorrhagic events were associated with the extent of fibrinogen breakdown, peak rt-PA levels, thrombocytopenia, prolongation of the activated partial thromboplastin time (APTT) to more than 90 seconds, weight of 70 kg or less, female gender, and physical signs of cardiac decompensation. Immediate intravenous beta-blocker therapy had no important effect on hemorrhagic events when compared with delayed beta-blocker therapy. Intracranial hemorrhages were more frequent among patients treated with the 150-mg rt-PA dose than with the 100-mg rt-PA dose (2.1% versus 0.5%, P less than 0.001). The extent of the plasmin-mediated hemostatic defect was also greater in patients receiving the 150-mg dose.

CONCLUSIONS

Increased morbidity due to hemorrhagic complications is associated with an invasive management strategy in patients with acute myocardial infarction. Our findings show the complex interaction of several factors in the occurrence of hemorrhagic events during thrombolytic therapy.

[The action of regulator peptides with different biological activities on the process of fibrin-monomer polymerization and on nonenzymatic fibrinolysis]

It is shown that preparations of regulatory peptides (RP): interleukin-1, thymoptin, and the endogenous nonpeptide opioid salsalinol produce a marked depolymerization effect on the fibrin-monomer and display nonenzymatic fibrinolytic activity in relation to unstabilized fibrin. Preparations of regulatory peptides thymalin and diphensin of rabbits intensify fibrin polymerization. A single intravenous infusion of diphensin preparation inhibits nonenzymatic fibrinolysis of blood plasma in vivo and in vitro. Repeated intramuscular injections of the immunoactive preparation thymoptin intensify the fibrinolytic properties of blood plasma in rats.

[The effect of tuftsin on fibrin polymerization in vitro and on the hemostatic system when administered intravenously to healthy animals]

Taftsine tetrapeptide has antiprocoagulatory properties in vitro in the presence of plasma. Taftsine exerts depolymerization influence on fibrin monomer in concentrations of 10(-1) to 10(-9) mg/ml. At intravenous injection in doses of 1 mg and 300 ug/kg, taftsine causes the increase in plasma clotting time and significant increase in enzymatic and nonenzymatic fibrinolysis. The effect can be observed during 120 min after injection of the peptide.

In vitro and ex vivo activities of CY216: comparison with other low molecular weight heparins

Low molecular weight (LMW) heparins achieve their anticoagulant effects by inhibiting prothrombin activation, catalyzing endogenous thrombin inhibition, and binding thrombin. The extent of which each of the three actions of LMW heparins contributes to the antithrombotic effectiveness of LMW in man has not been defined. Several studies have reported that ex vivo anti-factor Xa activities of LMW heparins correlate with efficacy and potential haemorrhagic complications. However, critical review of the data suggests that anti-factor Xa assays are basically surrogate tests for the mass of LMW heparins in patients' plasmas rather than reliable estimates of total catalytic concentrations of LMW heparins. Antithrombotic effectiveness of LMW heparins probably reflects their ability to inhibit coagulation in vivo. If the last concept proves correct, then results of tests which directly assess the extents to which LMW heparins have suppressed in vivo coagulation may provide more reliable markers for their antithrombotic effectiveness or lack thereof.