Elevated plasma tissue plasminogen activator and anti-THP-1 antibodies are independently associated with decreased graft survival in cardiac transplant recipients

Hemostatic and immunologic factors have been implicated in future cardiac events in patients with coronary artery disease. The role of these factors and their interaction is less established in cardiac transplant recipients. We sought to characterize the role of these factors in these patients. Cardiac transplant patients who presented for surveillance coronary angiography and/or endomyocardial biopsy were eligible for enrollment. Ninety-nine consecutive patients were enrolled. Plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1, von Willebrand factor, fibrin D-dimer, and anti-t-PA antibody were determined by enzyme-linked immunosorbent assays. Anti-THP-1 cell antibodies directed against a monocytic leukemia cell line were detected by incubating patient plasma with THP-1 cells. Bound antibody was detected using goat peroxidase-labeled immunoglobulin G directed against human immunoglobulins. Lipids were measured by enzymatic methods. Multivariate analysis identified the presence of anti-THP-1 cell antibodies (risk ratio 4.41, p = 0.002), t-PA antigen (risk ratio 1.10, p = 0.033), donor age 20 to 26 years (risk ratio 8.83, p = 0.042), and donor age >36 years (risk ratio 15.53, p = 0.009) as predictors of allograft failure. Altered hemostatic function, as demonstrated by elevated plasma t-PA antigen levels, is predictive of subsequent allograft failure in cardiac transplant recipients. In addition, the presence of anti-THP-1 cell antibodies in these patients is predictive of allograft failure.

A study of blood coagulation and fibrinolytic system in spontaneous subarachnoid hemorrhage. Correlation with hunt-hess grade and outcome

BACKGROUND

Subarachnoid hemorrhage (SAH) has been studied from various standpoints with the purpose of discovering criteria that might be useful in predicting the prognosis. In the literature a high incidence of coagulative and fibrinolytic disorders has been reported in SAH patients. A prospective study was performed to evaluate hemostatic plasmatic parameters in SAH patients.

METHODS

Hemostatic plasmatic parameters were prospectively studied in 76 patients with SAH. Both the coagulative (PT, APTT, fibrinogen, thrombin/antithrombin complex: TAT, and modified antithrombin III: MAT) and fibrinolytic (D-dimer) plasmatic systems were evaluated. Von Willebrand factor was also tested.

RESULTS

PT, APTT, and fibrinogen were within normal limits. High TAT levels were associated with clinical outcome since 16 patients out of 27 (59%) with unfavorable outcomes displayed TAT levels >20 ngzaq/L, as compared with 10 patients out of 38 (26%) with favorable outcomes. Plasmatic D-dimer, an index of subarachnoid clot lysis, was invariably found to be elevated. Nevertheless, very high levels (>1000 mcg/mL) were found in 16 patients out of 22 (73%) with unfavorable outcomes but in only 9 patients out of 38 (26%) with favorable outcomes. Significant D-dimer elevation showed a strong association with severe delayed ischemic deficit (DID). Patients were also tested for von Willebrand factor, displaying a specific increase in all cases.

CONCLUSION

The study provides evidence for an early activation of the coagulation and fibrinolytic system following SAH. Increase of plasmatic TAT parallels clinical outcome. A generalized increase of D-dimer was observed as well and D-dimer levels in the high range were associated with clinical outcome and poor results with DID. Our analysis shows close statistical significance between plasma levels of TAT, D-dimer, and outcome. A similar statistical significance has been found when comparing other known prognostic factors such as clinical and cerebral computerized tomography scan (CT) grade and outcome.

Coagulation activity and clinical outcome in unstable coronary artery disease

In the current study, we investigated molecular markers of coagulation activity, ie, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin (TAT) complex, soluble fibrin (SF), and D-dimer, and their relation to death, myocardial infarction, and refractory angina during and after anticoagulant treatment in unstable coronary artery disease. Patients with unstable coronary artery disease (N=320) were randomized to a 72-hour infusion with either inogatran, a low-molecular-mass direct thrombin inhibitor, or unfractionated heparin. During the 30-day follow-up, a 40% lower event rate was seen in patients with high compared with low baseline levels of TAT or SF. High baseline levels of coagulation activity were correlated with a larger decrease during treatment. Patients with decreased compared with raised F1+2 or TAT levels after 6 hours of treatment had a 50% lower event rate at 30 days (F1+2, P=0.04; TAT, P=0.02). At the cessation of antithrombin treatment, there was a clustering of cardiac events that tended to be related to a rise in the levels of TAT and the other markers. During long-term follow-up (median, 29 months), there was a relation between higher baseline levels of D-dimer (P=0.003) and increased mortality. High baseline levels of molecular markers of coagulation activity might identify patients with a thrombotic condition (as the major cause of instability) who are good responders to anticoagulant therapy, with a larger decrease in coagulation activity during treatment and a decreased risk of ischemic events. However, this early benefit is lost during long-term follow-up when high baseline levels of coagulation activity are associated with a raised risk of early reactivation and increased mortality.

Diagnostic accuracy of triage tests to exclude pulmonary embolism

We performed a study in 403 prospectively included patients with suspected pulmonary embolism to compare the accuracy of a combination of the SimpliRED D-dimer assay and an intuitive clinical probability estimate with either one alone. Based on a conjoint diagnostic refer, ence standard, including ventilation-perfusion lung scintigraphy and pulmonary angiography, the prevalence of pulmonary embolism was 31%. We demonstrated a high sensitivity (98%, 95% CI 95-100) and negative predictive value (94%, 95% CI 79-99) for the combination of the two tests. These figures were more favorable than for either test alone. The specificity of the combination was lower (11%, 95% CI 9-12) and consequently the proportion of patients in whom further diagnostic tests would have been avoided was only 8%. We conclude that the combined use of the SimpliRED test and the clinical probability estimate attains a higher sensitivity than either test alone. However, there remains a risk of false negatives and the exclusion efficiency is limited.

Chronic disseminated intravascular coagulation after surgery for abdominal aortic aneurysm: clinical and haemostatic response to dalteparin

A 77-year-old man developed chronic disseminated intravascular coagulation (DIC) after surgical repair of a large infrarenal aortic aneurysm. Self-administered subcutaneous dalteparin therapy (5000 units o.d.) led to rapid relief of symptoms and sustained improvements in his platelet count and fibrinogen level; activation of coagulation and fibrinolysis appeared to be relatively unaffected. Long-term treatment with low-molecular-weight heparin can provide good symptomatic control of chronic DIC associated with abdominal aortic aneurysm.

Increased activation of protein C, but lower plasma levels of free, activated protein C in uraemic patients: relationship with systemic inflammation and haemostatic activation

Chronic renal failure (CRF) courses with both systemic inflammatory reaction and haemostatic activation. We explored the relationship of these processes with plasma levels of free, activated protein C (APC) and complexes of APC with its inhibitors in patients with CRF under conservative treatment. Plasma concentrations of inflammatory cytokines [tumour necrosis factor alpha (TNFalpha) and interleukin 8], acute-phase proteins (C-reactive protein, fibrinogen, alpha1-anti-trypsin and von Willebrand factor), and markers of haemostatic activation (thrombin-anti-thrombin complexes, plasmin-anti-plasmin complexes, and fibrin and fibrinogen degradation products) were higher in patients than in controls. Inflammatory and haemostatic markers were significantly and positively correlated. Total plasma APC and APC:alpha1-anti-trypsin (alpha1AT) complexes were 44% and 75% higher in patients than in controls (P = 0.0001), whereas free APC was 20% lower (P < 0.015). No significant difference was observed in APC:protein C inhibitor (PCI) complexes between both groups. The free/total APC ratio was significantly lower in patients than in controls (P < 0.0001). Total plasma APC and APC:alpha1AT were positively correlated with activation markers of haemostasis and acute-phase proteins, whereas free APC was inversely correlated with plasma levels of creatinine, acute-phase proteins and fibrin degradation products (FnDP). Systemic inflammation and activation of haemostasis are interrelated processes in CRF. APC generation was increased in response to elevated thrombin production, but the inflammatory reaction, associated with increased synthesis of alpha1AT, reduced its anticoagulant effect. Lower free plasma APC in CRF may be pathogenically associated with atherothrombosis, a major cause of death in this disease.

Prothrombotic inherited abnormalities other than factor V Leiden mutation do not play a role in venous thrombosis in inflammatory bowel disease

OBJECTIVES

Because the incidence of thromboembolism is increased in patients with inflammatory bowel disease, we attempted to assess the role of prothrombotic inherited coagulation abnormalities in the development of thrombosis.

METHODS

Four populations were compared: 15 patients with inflammatory bowel disease and a previous venous thrombosis, 58 control patients with inflammatory bowel disease but without thrombosis, 110 patients without inflammatory bowel disease but with previous deep venous thrombosis, and 84 healthy subjects. Inherited and acquired risk factors of venous thrombosis, e.g., factor V Leiden and prothrombin 20210A mutations, C677T methylenetetrahydrofolate reductase polymorphism, a polymorphism located in exon 13 of factor V gene, inflammatory and hypercoagulability markers were studied in each population.

RESULTS

In the study, 14.3% of thrombotic patients with inflammatory bowel disease had factor V Leiden mutation versus 0% of control patients with inflammatory bowel disease (p = 0.04), 15.5% of thrombotic patients without inflammatory bowel disease (NS) and 3.6% of the healthy controls. A total of 14% of thrombotic patients with inflammatory bowel disease and 11.8% of thrombotic patients without inflammatory bowel disease carried prothrombin 20210A mutation, compared to 1.7% of control patients with inflammatory bowel disease; however, the difference was just below significance. Other inherited coagulation abnormalities were not statistically significantly different among the four populations.

CONCLUSIONS

Our study confirms that factor V Leiden mutation increases the risk for thrombotic events but is not more frequent in patients with inflammatory bowel disease. Our results do not support the role of other thrombotic risk factors.

Haemostasis in Relation to Dietary Fat as Estimated by Erythrocyte Fatty Acid Composition: The Prime Study

We investigated whether haemostatic variables were related with dietary fatty acid composition as estimated by the fatty acid content of erythrocytes. Subjects were a subsample (n=283) of the participants in the Prospective Epidemiological Study of Myocardial Infarction (PRIME) Study. Factor VII, fibrinogen, tissue-type plasminogen activator antigen (tPA-ag), plasminogen activator inhibitor type 1 (PAI-1), D-dimer and von Willebrand factor (vWf) were measured and the fatty acid composition was determined in the phospholipids of total erythrocytes by gas chromatography. Statistical analyses were performed using multiple linear regression analyses with adjustment for age, center and body mass index. tPA-ag was significantly related to the n-3 fatty acids derived from fish. This was reflected in an inverse association of all n-3 fatty acids combined with tPA-ag (beta=-0.37 ng/ml/%, 95% confidence intervals: -0.45, -0.29, P<.01). Positive and significant associations of D-dimer with arachidic and eicosamonoenoic acid were observed (P<.01). No relationships were found between fatty acids and fibrinogen, vWf, PAI-1 or factor VII. The results of this study suggest that consumption of n-3 fatty acids derived from fish may favourably influence tPA-ag.

Diagnostic value of the D-dimer test in deep vein thrombosis: improved results by a new assay method and by using discriminate levels

Previous studies have suggested that D-dimer testing reliably selects patients for whom duplex sonography should be performed for diagnosis of deep vein thrombosis (DVT). However, the interassay correlation is poor. Therefore, we tested four D-dimer methods for their ability to rule out DVT, including the Miniquant test, a new D-dimer assay method. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were calculated vs. duplex sonography. Twenty-nine of 108 (27%) patients with suspected DVT were diagnosed as having DVT by sonography. The Vidas enzyme-linked immunoabsorbent assay (ELISA) test, the Miniquant turbidimetric test and the latex agglutination test for D-dimer all provided discriminate values for achieving 100% sensitivity and 100% NPV. D-dimer results demonstrated higher specificity and PPV in the outpatient vs. the inpatient group. This probably reflects the higher proportion of inpatients with comorbid conditions, such as malignancy and postsurgery status, in whom D-dimer results show very poor specificity and PPV. The new Miniquant turbidimetric assay performed as well as the more established ELISA method. We conclude that the D-dimer tests were shown to possess the necessary sensitivity and NPV to be useful in screening patients with suspected DVT. A negative D-dimer test in selected patients could be helpful in reducing the number of sonograms performed for diagnosis of DVT.

Cyclosporine-associated thrombotic microangiopathy during daclizumab induction: a suggested therapeutic approach

A woman on daclizumab developed thrombotic microangiopathy secondary to cyclosporine after a living-unrelated kidney transplant. Despite cyclosporine discontinuation, hemolysis persisted. The second dose of daclizumab was postponed 24 h, and after a maximum of two sessions of plasmapheresis (to avoid further modifications in daclizumab schedule) with plasma exchange, daclizumab was administered. Plasma infusions were prescribed until D-dimer and fibrinogen-degradation products normalized; thereafter, FK-506 was started without recurrence of the hemolytic picture and renal function restored. This observation suggests that in patients on daclizumab who develop thrombotic microangiopathy secondary to immunosuppressants, if discontinuation of the offending drug is unsuccessful, plasmapheresis with plasma exchange can be performed when the lowest levels of daclizumab exist, followed by daclizumab infusion. Plasma prescription must be continued thereafter until D-dimer and figrinogen-degradation products normalize. However, if hemolysis persists when daclizumab levels are high, plasma infusions are useful and plasmapheresis avoided. FK-506 administration did not result in recurrence of hemolysis during daclizumab induction.

C-reactive protein, fibrin D-dimer, and incident ischemic heart disease in the Speedwell study: are inflammation and fibrin turnover linked in pathogenesis?

Plasma levels of C-reactive protein (CRP, a marker of the reactant plasma protein component of the inflammatory response) and of fibrin D-dimer (a marker of cross-linked fibrin turnover) have each been associated in recent studies with the risk of future ischemic heart disease (IHD). Previous experimental studies have shown that fibrin degradation products, including D-dimer, have effects on inflammatory processes and acute-phase protein responses. In the Speedwell Prospective Study, we therefore measured CRP and D-dimer levels in stored plasma samples from 1690 men aged 49 to 67 years who were followed-up for incident IHD for an average of 75+/-4 months (mean+/-SD) and studied their associations with each other, with baseline and incident IHD, and with IHD risk factors. CRP and D-dimer levels were each associated with age, plasma fibrinogen, smoking habit, and baseline evidence of IHD. CRP was associated with D-dimer (r=0.21, P<0.00001). On univariate analyses, both CRP and D-dimer were associated with incident IHD. The incidence of IHD increased with CRP independently of the level of D-dimer (P=0.0002) and also increased with D-dimer independently of the level of CRP (P=0.048). In multivariate analyses, inclusion of D-dimer and conventional risk factors reduced the strength of the association between CRP and incident IHD; likewise, inclusion of CRP and conventional risk factors reduced the strength of the association between D-dimer and incident IHD. We conclude that although these respective markers of inflammation and fibrin turnover show modest association with each other in middle-aged men, they may have additive associations with risk of incident IHD. Further larger studies are required to test this hypothesis.

The Fibrin Assay Comparison Trial (FACT): evaluation of 23 quantitative D-dimer assays as basis for the development of D-dimer calibrators. FACT study group

Although D-dimer has gained widespread clinical use as a parameter for detection of in vivo fibrin formation, the issue of standardization of D-dimer assays remains to be resolved. The FACT study was performed to generate basic data for development of calibrators and standard preparations. A set of 86 samples, including plasma samples from patients with DIC, DVT. and other clinical conditions, serial dilutions of pooled plasma samples, and plasma samples containing fibrinogen- and fibrin derivatives, were distributed to 12 manufacturers of D-dimer assays. D-dimer assays differ concerning specificity for crosslinked fibrin, and preference for either high molecular weight fibrin complexes, or low molecular weight fibrin degradation products. Terminal plasmin digests of fibrin clots for calibration produce aberrant results in some assays, especially those with preference for high molecular weight crosslinked fibrin derivatives. The best conformity is achieved by the use of pooled plasma samples from patients with high levels of D-dimer antigen in plasma. In vitro preparations containing a comparable composition of fibrin derivatives to clinical plasma samples may also serve as reference material.

Prognostic value of fibrinolytic tests for hospital outcome in patients with acute upper gastrointestinal hemorrhage

GOALS

We assessed the predictive value of fibrinolytic tests for hospital outcome in a prospective study of 84 nonconsecutive patients with acute upper gastrointestinal hemorrhage.

STUDY

Six readily available parameters of activated fibrinolysis (fibrinogen, D-dimer, tissue plasminogen activator [TPA], plasminogen activator inhibitor type 1 [PAI-1], TPA--PAI-1 complexes, and plasmin-alpha 2-antiplasmin complexes) were tested for association with hospital outcome. Patients were divided into the following three groups: patients who survived and did not require transfusion or surgery, those who survived without surgery but required transfusion, and those who required surgery or died.

RESULTS

Patients with adverse outcome (surgery and/or death) showed significantly higher plasma levels of D-dimer than patients with favorable outcome (p = 0.01). Plasma concentrations of D-dimer >300 ng/mL showed a 20.5% positive predictive value of adverse outcome, with a relative risk of 7.5 (95% CI: 1--57%). Patients who required transfusion showed significantly higher plasma levels of TPA (p = 0.01). A positive correlation between endoscopic bleeding stigmata and D-dimer in the subgroup of patients without liver cirrhosis was found (p = 0.02); however, in the multivariate logistic regression analysis the concentration of D-dimer did not appear as an independent predictor of adverse outcome.

CONCLUSIONS

These findings are consistent with the role of increased local fibrinolysis in the digestive tract, particularly of D-dimer, in patients with upper gastrointestinal hemorrhage and adverse outcome. Accordingly, plasma fibrinolytic tests may constitute an appropriate prognostic marker in upper gastrointestinal bleeding.

Prospective study of fibrinolytic factors and incident coronary heart disease: the Atherosclerosis Risk in Communities (ARIC) Study

The fibrinolytic system may play a role in the pathogenesis of coronary heart disease (CHD), but existing prospective studies have not consistently shown an independent association between fibrinolytic factors and CHD. None has reported an association between plasminogen and CHD incidence. In the prospective Atherosclerosis Risk in Communities (ARIC) Study of middle-aged adults, we examined the association of incident CHD with several fibrinolytic factors: tissue plasminogen activator antigen, plasminogen activator inhibitor-1, plasminogen, and fibrin fragment D-dimer as well as a marker of coagulation activation (prothrombin fragment F1.2). We measured these in stored baseline plasma samples of 326 subjects who developed CHD and, for comparison, a stratified random sample of the entire cohort (n=720). Tissue plasminogen activator and plasminogen activator inhibitor-1 antigen levels were associated positively with CHD incidence in analyses adjusted for age, race, and sex but were not associated with CHD after adjustment for other risk factors. Plasminogen and D-dimer levels were associated positively and independently with CHD incidence; the multivariable-adjusted relative risks (95% CIs) for the highest versus lowest quintiles were 2.20 (1.2 to 4.2) for plasminogen and 4.21 (1.9 to 9.6) for D-dimer. F1.2 was not associated with CHD incidence. Our findings lend support for a link between fibrinolytic factors and CHD incidence. A positive association between plasminogen and CHD is seemingly opposite the direction expected but may reflect a compensatory response to impaired plasminogen activation in subjects prone to CHD.

Performances of a new, automated latex assay for the exclusion of venous thromboembolism

The performance of a new latex-enhanced turbidimetric assay, D-Dimer PLUS, has been evaluated with two analyzers performing various coagulation assays: the BCS Analyzer and the BCT Analyzer. A precision study showed total coefficients of variation ranging from 2.7 to 11.1% with the BCS Analyzer and from 2.5 to 6.6% with the BCT Analyzer. We investigated the ability of D-Dimer PLUS to exclude venous thromboembolism in 312 outpatients suspected of either pulmonary embolism or deep venous thrombosis. Three months follow-up was available for all patients. With the BCS Analyzer, we determined a cut-off value of 190 ng/ml, which gave a sensitivity of 97.9% [95% confidence interval (CI), 92.6-99.7%], a specificity of 37.9% (95% CI, 30.9-43.8%) and a negative predictive value of 97.6% (95% CI, 91.7-99.7%). With the BCT Analyzer, at a cut-off value of 130 ng/ml, sensitivity was 96.8% (95% CI, 91.0-99.3%), specificity was 45.2% (95% CI, 38.5-51.2%) and the negative predictive value was 97% (95% CI, 91.6-99.4). This new assay is fast and fully automated, and its performance is suitable to exclude venous thromboembolism. Management studies should be performed to assess its utility.

Conebulization of surfactant and urokinase restores gas exchange in perfused lungs with alveolar fibrin formation

Alveolar fibrin generation has been suggested to possess strong surfactant-inhibitory potency. In perfused rabbit lungs, fibrin formation in the alveolar space was induced by sequential ultrasonic aerosolization of fibrinogen and thrombin, and the efficacy of rescue administration of surfactant and urokinase was investigated. Ventilation-perfusion (VA/Q) distribution was assessed by the multiple inert gas elimination technique. Aerosolization of fibrinogen (approximately 20 mg/kg body wt) increased shunt flow to approximately 7%. Sequential nebulization of fibrinogen and thrombin (1.3 U/kg body wt) caused alveolar fibrin deposition, documented immunohistologically, and provoked marked shunt flow, progressing to approximately 22% at the end of the experiments. The hemodynamics were virtually unchanged. Rescue aerosolization of natural bovine surfactant (15 mg/kg body wt) or urokinase-type plasminogen activator (4,500 U/kg body wt), undertaken after fibrin formation, improved gas exchange but progressive shunt flow still occurred (efficacy, surfactant > urokinase). In contrast, conebulization of surfactant and urokinase reversed shunt flow to approximately 7%, with an increased appearance of normal VA/Q matching. We conclude that alveolar fibrin formation is a potent surfactant-inhibitory mechanism in intact lungs, provoking severe VA/Q mismatch with a predominance of shunt flow, and that rescue aerosolization of surfactant plus urokinase may offer restoration of gas exchange under these conditions.

Rapid D-dimer testing and pre-test clinical probability in the exclusion of deep venous thrombosis in symptomatic outpatients

We assessed the performance of three rapid D-dimer tests (Auto Dimertest, VIDAS and Tinaquant) in combination with a pretest clinical probability model for deep venous thrombosis (DVT) in 106 consecutive outpatients with suspected DVT. Contrast venography or colour-coded duplex ultrasonography demonstrated the presence of DVT in 47 patients (14 distal DVT and 33 proximal DVT). First, we assessed the accuracy indices for different cut-off levels of the rapid D-dimer tests. Sensitivity was found to be 97.9-100%, negative predictive value (NPV) was 96.3-100%, and the exclusion rate was 24.5-31.1%. Next, the patients were grouped according to the pre-test clinical probability model in categories with low, moderate or high probability. In patients with a low pre-test probability, DVT would have been directly ruled out and the patients would not have undergone further investigations. In patients with a moderate probability, D-dimer testing and, in the case of a positive result, objective testing would have been performed and, in the case of a negative result, they would have been ruled out of having DVT. Patients with high probability would directly have undergone objective tests for DVT. The combination with the pre-test clinical probability model improved the exclusion rate (43.5-44.6%), whereas sensitivity (97.5-100%) and NPV (97.6-100%) remained roughly unchanged. The combination of rapid D-dimer tests with a pre-test clinical probability model may help to reduce unnecessary work-up in patients with suspected DVT.

Efficacy and safety of recombinant human activated protein C for severe sepsis

BACKGROUND

Drotrecogin alfa (activated), or recombinant human activated protein C, has antithrombotic, antiinflammatory, and profibrinolytic properties. In a previous study, drotrecogin alfa activated produced dose-dependent reductions in the levels of markers of coagulation and inflammation in patients with severe sepsis. In this phase 3 trial, we assessed whether treatment with drotrecogin alfa activated reduced the rate of death from any cause among patients with severe sepsis.

METHODS

We conducted a randomized, double-blind, placebo-controlled, multicenter trial. Patients with systemic inflammation and organ failure due to acute infection were enrolled and assigned to receive an intravenous infusion of either placebo or drotrecogin alfa activated (24 microg per kilogram of body weight per hour) for a total duration of 96 hours. The prospectively defined primary end point was death from any cause and was assessed 28 days after the start of the infusion. Patients were monitored for adverse events; changes in vital signs, laboratory variables, and the results of microbiologic cultures; and the development of neutralizing antibodies against activated protein C.

RESULTS

A total of 1690 randomized patients were treated (840 in the placebo group and 850 in the drotrecogin alfa activated group). The mortality rate was 30.8 percent in the placebo group and 24.7 percent in the drotrecogin alfa activated group. On the basis of the prospectively defined primary analysis, treatment with drotrecogin alfa activated was associated with a reduction in the relative risk of death of 19.4 percent (95 percent confidence interval, 6.6 to 30.5) and an absolute reduction in the risk of death of 6.1 percent (P=0.005). The incidence of serious bleeding was higher in the drotrecogin alfa activated group than in the placebo group (3.5 percent vs. 2.0 percent, P=0.06).

CONCLUSIONS

Treatment with drotrecogin alfa activated significantly reduces mortality in patients with severe sepsis and may be associated with an increased risk of bleeding.