Biomarkers of Thrombosis in ST-Segment Elevation Myocardial Infarction: A Substudy of the ATOLL Trial Comparing Enoxaparin Versus Unfractionated Heparin.

BACKGROUND: The aim was to compare the peri-procedural biomarkers of coagulation and platelet activation in patients randomly allocated to intravenous enoxaparin or unfractionated heparin (UFH) in the ATOLL randomized trial (NCT00718471). METHODS AND RESULTS: A total of 129 patients (n = 58 enoxaparin and n = 71 UFH) admitted for ST-segment elevation myocardial infarction (STEMI) treated by percutaneous coronary intervention (PCI) were included in this substudy of the ATOLL trial. Activated partial thromboplastin time ratio, anti-Xa activity, von Willebrand factor antigen, prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT), tissue factor pathway inhibitor and soluble CD40 ligand were measured at sheath insertion (T1) and at the end of the PCI (T2) and correlated with 1-month clinical outcomes. Target anticoagulation levels at T2 were more readily achieved in patients receiving enoxaparin compared to those receiving UFH (80.3 vs 18.2%, p < 0.0001). Increased levels of F1 + 2 and TAT measured at T2 were associated with the incidence of the composite ischemic endpoint (p = 0.04 and p = 0.03) and all-cause mortality (p < 0.0001 and p = 0.002). Release of F1 + 2 between T1 and T2 also predicted the composite ischemic endpoint (312 ± 513 vs 37 ± 292, p = 0.04) and net clinical outcome (185 ± 405 vs 3.2 ± 278, p = 0.03). CONCLUSIONS: During primary PCI, enoxaparin achieved therapeutic levels more frequently than UFH. Higher level of thrombin generation measured at the end of the PCI procedure was associated with more frequent ischemic events.

Haematological spectrum and genotype-phenotype correlations in nine unrelated families with RUNX1 mutations from the French network on inherited platelet disorders.

BACKGROUND: Less than 50 patients with FPD/AML (OMIM 601309) have been reported as of today and there may an underestimation. The purpose of this study was to describe the natural history, the haematological features and the genotype-phenotype correlations of this entity in order to, first, screen it better and earlier, before leukaemia occurrence and secondly to optimize appropriate monitoring and treatment, in particular when familial stem cell transplantation is considered. METHODS: We have investigated 41 carriers of RUNX1 alteration belonging to nine unrelated French families with FPD/AML and two syndromic patients, registered in the French network on rare platelet disorders from 2005 to 2015. RESULTS: Five missense, one non-sense, three frameshift mutations and two large deletions involving several genes including RUNX1 were evidenced. The history of familial leukaemia was suggestive of FPD/AML in seven pedigrees, whereas an autosomal dominant pattern of lifelong thrombocytopenia was the clinical presentation of two. Additional syndromic features characterized two large sporadic deletions. Bleeding tendency was mild and thrombocytopenia moderate (>50 x10(9)/L), with normal platelet volume. A functional platelet defect consistent with a δ-granule release defect was found in ten patients regardless of the type of RUNX1 alteration. The incidence of haematological malignancies was higher when the mutated RUNX1 allele was likely to cause a dominant negative effect (19/34) in comparison with loss of function alleles (3/9). A normal platelet count does not rule out the diagnosis of FPD/AML, since the platelet count was found normal for three mutated subjects, a feature that has a direct impact in the search for a related donor in case of allogeneic haematopoietic stem cell transplantation. CONCLUSIONS: Platelet dysfunction suggestive of defective δ-granule release could be of values for the diagnosis of FPD/AML particularly when the clinical presentation is an autosomal dominant thrombocytopenia with normal platelet size in the absence of familial malignancies. The genotype-phenotype correlations might be helpful in genetic counselling and appropriate optimal therapeutic management.

[Evaluation of the automated coagulation analyser Sysmex(®) CS-5100 (Siemens)]. / Évaluation de l'automate d'hémostase Sysmex(®) CS-5100 (Siemens).

The Sysmex® CS-5100 is a fully automated multiparameter hemostasis analyzer equipped with a photo-optical clot detection unit, a cap-piercing system and a pre-analytical check screens for interfering substances such as bilirubin, lipids and haemolysis (HIL system). It is designed to perform coagulation tests as well as coagulometric, chromogenic and immunologic assays. The aim of the present study was to evaluate its performance. The intra-assay and inter-assay coefficients of variation (CV) were below 6% for most parameters both in the normal and in the pathological range (exceptions: intra-assay for severe factor VIII deficiency (CV = 7.4%) and for vWFRco (CV = 7.3% and 7.7%); and inter-assay for anti-Xa activity (CV = 8.8%) and vWFRco (9.3% and 11.1%). The measured lower limits of linearity for factor VIII and factor V were satisfactory. No sample or reagent carryover was detected in the conditions of the study. Our results demonstrated that using the Sysmex® CS-5100 analyzer, routine coagulation testing can be performed with satisfactory precision. This automate has the advantage of being connectable to an automation chain.

Thrombophilia Associated with Anti-DFS70 Autoantibodies.

CONTEXT: Anti-DFS70 antibodies are the most frequent antinuclear antibodies (ANA) found in healthy individuals. We assessed the clinical significance of the presence of anti-DFS70 antibodies. METHODS: We defined a group of patients (n = 421) with anti-DFS70 antibodies and a group of patients (n = 63) with a history of idiopathic arterial and/or venous thrombotic disease and/or obstetric complication (i.e. ≥ 3 miscarriages, fetal death or premature birth with eclampsia). Anti-DFS70 antibodies prevalence was also assessed in a cohort of 300 healthy blood donors. RESULTS: The prevalence of thrombotic disease and/or obstetric complication in the 421 patients with anti-DFS70 antibodies was 13.1% (n = 55) and the prevalence of connective tissue disease was 19% (n = 80). Among the 63 patients with a history of thrombosis and/or obstetric complications, 7 (11.1%) had anti-DFS70 antibodies and among the latter, 5 had no common thrombophilic factor. In contrast, the prevalence of anti-DFS70 antibodies was of 3.0% (9 out of 300) in healthy donors. Finally, the Activated Partial Thromboplastin Time (aPTT) ratio of patients with a history of thrombosis and anti-DFS70 antibodies was lower than the aPTT ratio of other patients, suggesting that thrombotic patients with anti-DFS70 antibodies may have a hypercoagulable state. CONCLUSION: We described here for the first time an immune procoagulant state involving anti-DFS70 antibodies.

Safety and efficacy of oral direct inhibitors of thrombin and factor Xa in antiphospholipid syndrome.

BACKGROUND: Long-term anticoagulation is recommended in antiphospholipid syndrome with thrombosis in order to prevent recurrences. While the current mainstay relies on vitamin K antagonists, their long-term maintenance may remain challenging. OBJECTIVES: To report on the safety and the efficacy of oral direct inhibitors of thrombin and factor Xa (ODIs) in antiphospholipid syndrome (APS). METHODS: We performed a descriptive analysis of patients with APS enrolled in a French multicentre observational cohort between January 2012 and March 2014 and receiving ODIs. The main outcomes were the occurrence of a thrombotic recurrence or bleeding events. RESULTS: Twenty-six patients with APS (primary in 12) received ODIs. Twenty patients had been previously treated with VKA (n=19), or fondaparinux (n=1) for a median duration of 3years. ODIs were introduced as second-line therapy because of INR lability/therapeutic simplification (n=17), recurrent thrombosis (n=1), VKA's associated bleeding event (n=1), and atrial fibrillation (n=1). Six patients received ODIs as first-line therapy. After a median [IQR] follow-up of 19 [8-29] months, one relapse of arterial thrombosis, two bleeding events (hypermenorrhea and rectal bleeding under rivaroxaban) and one recurrent migraine were reported, leading to discontinuation of therapy in these 4 patients. CONCLUSION: ODIs might be an alternative therapeutic option in APS. Prospective studies are warranted to evaluate their safety in this condition.

[Evaluation of the automated coagulation analyzer Sysmex(®) CS-2100i (Siemens)]. / Évaluation de l'automate d'hémostase Sysmex(®) CS-2100i (Siemens) pour les tests TCA, TP, fibrinogène, facteurs V et VIII, antithrombine et D-dimères.

The Sysmex(®) CS-2100i is a fully automated multiparameter hemostasis analyzer equipped with a photo-optical clot detection unit, a cap-piercing system and a pre-analytical check screens for interfering substances such as bilirubin, lipids and haemolysis (HIL system). It is designed to perform coagulation tests as well as chromogenic and immunologic assays. The aim of the present study was to evaluate its performance. The tests performed were routine coagulation (prothrombin time, activated partial thromboplastin time, fibrinogen, factor VIII and factor V), chromogenic (antithrombin) and immunologic assays (D-Dimer). The intra-assay and inter-assay coefficients of variation (CV) were below 5% for most parameters both in the normal and in the pathological range (exceptions: intra-assay CV = 5.65% for the fibrinogen in the low range of concentrations; and inter-assay CV = 6% for clotting factor). The measured lower limits of linearity for factor VIII and factor V were satisfactory. No sample or reagent carryover was detected in the conditions of the study. Our results demonstrated that using the CS-2100i analyzer, routine coagulation testing can be performed with satisfactory precision.

Enoxaparin anticoagulation monitoring in the catheterization laboratory using a new bedside test.

OBJECTIVES: This study evaluated the ability of the bedside test Hemochron Jr. Hemonox (International Technidyne Corporation, Edison, New Jersey) to identify patients with insufficient anti-Xa activity level in the catheterization laboratory. BACKGROUND: Inadequate anticoagulation in patients undergoing percutaneous coronary intervention (PCI) is associated with increased periprocedural ischemic events. METHODS: In 296 unselected patients undergoing catheterization and/or PCI, whole blood Hemonox clotting time (CT) and activated partial thromboplastin time (aPTT) were measured at baseline (T1) and 10 min after the intravenous administration of enoxaparin (T2) in patients receiving additional enoxaparin and compared with plasma chromogenic anti-Xa activity level. RESULTS: Median values were 0.1 IU/ml (interquartile range [IQR]: 0.1 to 0.1 IU/ml) and 0.87 IU/ml (IQR: 0.74 to 1.03 IU/ml) for anti-Xa; 74 s (IQR: 70 to 81 s) and 143 s (IQR: 114 to 206 s) for Hemonox CT; and 44 s (IQR: 39 to 50 s) and 72 s (IQR: 58 to 93 s) for aPTT at T1 and T2, respectively. When using Hemonox CT to discriminate patients with anti-Xa level <0.5 IU/ml, the area under the receiver operating characteristic curve was 0.95 +/- 0.01 (95% confidence interval [CI]: 0.93 to 0.97) versus 0.89 +/- 0.01 (95% CI: 0.86 to 0.92) for aPTT. The threshold value of 120 s was associated with a 94.9% (95% CI: 91.1% to 97.4%) sensitivity and a 73.3% (95% CI: 67.6% to 78.5%) specificity to detect patients with inadequate anti-Xa level (<0.5 IU/ml) and positive predictive and negative predictive values of 73.9% (95% CI: 68.7% to 79.0%) and 94.78% (95% CI: 91.8% to 97.8%), respectively. CONCLUSIONS: Hemonox CT appears to be a fast and reliable bedside test for detecting patients insufficiently anticoagulated and needing adjustment of anticoagulation therapy with enoxaparin before PCI.

Point-of-care versus central laboratory coagulation testing during haemorrhagic surgery. A multicenter study.

Delay in collecting coagulation test results from a central laboratory is one of the critical issues to efficiently control haemostasis during surgery. The aim of this multicenter study was to compare the performance of a point-of-care (POC) device (CoaguChek Pro DM) with the central laboratory-based coagulation testing during haemorrhagic surgery. For this purpose, 93 patients undergoing major surgical procedure were prospectively included in three centers. Blood was drawn from all patients before surgical incision and from most patients during surgical procedure after a blood loss of 25% or more was observed. When expressed in activity percentage, POC-based prothrombin time (PT) was in good agreement with central laboratory test result with coefficient of correlation in the range from 0.711 to 0.960 in the three centers. Comparison was less conclusive when PT was expressed in seconds or as the patient-to-control ratio and for activated partial thromboplastin time, with significantly shorter clotting times and lower ratios obtained on the POC device. On-site PT (in activity percentage) monitoring would have induced no significant change in fresh frozen plasma (FFP) transfusion in patients when compared to central laboratory monitoring. Test results were obtained in less than 5 minutes when performed using the POC device versus a median turnaround time of 88 minutes (range: 29-235 minutes) when blood collection tubes were sent to the central laboratory. These results suggest that, in providing a rapid answer, POC-based monitoring of PT (in percentage) using the CoaguChek device could be validly used in patients undergoing haemorrhagic surgical procedures.

Potentiation of fluindione or warfarin by dexamethasone in multiple myeloma and AL amyloidosis.

OBJECTIVES: Patients with primary systemic (AL) amyloidosis or multiple myeloma are frequently treated with cyclic dexamethasone (DXM) courses and often require oral anticoagulants. We previously reported a strong potentiation of oral anticoagulants with intravenous methylprednisolone and observed a similar potentiation with DXM in 3 patients, which led us to prospectively investigate the interaction between DXM and oral anticoagulants. METHODS: Nine patients with multiple myeloma (n=6) or AL amyloidosis (n=3), including 6 prospective patients, taking fluindione (n=8) or warfarin (n=1), were studied for a total of 10 cycles. DXM (40 mg/day for 4 days every 28 days) was administered alone (n=4) or with melphalan (n=5). One patient was studied for 2 consecutive cycles after a moderate increase in the international normalized ratio (INR) during the first course of DXM. International normalized ratio (INR) was measured serially during DXM administration. Plasma oral anticoagulant concentrations were measured for 5 cycles. RESULTS: The mean INR increased from 2.75 (range: 1.80-3.6) at baseline to 5.22 (3.09-7.07) after DXM. Oral anticoagulants were transiently stopped during 8 cycles and 1 mg oral vitamin K was given during 2. No serious bleeding was observed. Plasma oral anticoagulant concentrations increased after DXM administration. In controls receiving DXM without oral anticoagulants, DXM alone did not increase prothrombin time. CONCLUSION: High dose DXM can potentiate oral anticoagulants and elevate INR substantially. INR should therefore be monitored repeatedly during concomitant administration of these 2 drugs to allow individual adaptation of oral anticoagulant doses.

Anti-factor Xa kinetics after intravenous enoxaparin in patients undergoing percutaneous coronary intervention: a population model analysis.

AIM: Recent studies have suggested that intravenous (i.v.) enoxaparin could be used as antithrombotic therapy in patients ongoing percutaneous coronary intervention (PCI). However, anti-Xa pharmacokinetics following different i.v. dosing regimens is not clearly established. METHODS: A population pharmacokinetic analysis was developed using anti-Xa activities measured in 546 patients who received a single 0.5 mg kg(-1) i.v. dose of enoxaparin immediately before PCI. Effects of higher doses (0.75 mg kg(-1) and 1 mg kg(-1)) and/or additional bolus after the initial administration were similarly simulated. RESULTS: Enoxaparin anti-Xa time profiles were best described by a one-compartment model with zero-order kinetics. Mean population parameters (intersubject variability, %) were CL 1.2 l h(-1) (33), V 2.9 l (30) and zero-order input 0.25 h (24). With a single bolus of 0.5 mg kg(-1), the totality of the patients reached an effective anticoagulation level (anti-Xa >0.5 IU ml(-1)) and only 2.5% reached levels above 1.5 IU ml(-1). Simulations showed that greater doses (0.75 mg kg(-1) and 1 mg kg(-1)) prolonged the duration of anticoagulation (3.4 and 4.1 h, respectively) compared with the 0.5 mg kg(-1) bolus (2.7 h) and markedly increased the proportion (48% and 79%, respectively) of patients with anti-Xa levels >1.5 IU ml(-1). For delayed and/or prolonged procedures, patients could be administered a second bolus of half the initial dose in a time interval between 90 min to 2 h after in order to maintain similar anticoagulation profile levels. CONCLUSIONS: A single 0.5 mg kg(-1) i.v. dose of enoxaparin reached anticoagulation levels adequately and should be safer compared with greater doses for anticoagulation in patients undergoing an elective PCI. An additional second bolus could be proposed in patients with delayed or prolonged procedures.

Dosing strategy in patients with renal failure receiving enoxaparin for the treatment of non-ST-segment elevation acute coronary syndrome.

BACKGROUND: Enoxaparin therapy is recommended for the initial treatment of patients with non-ST-segment elevation acute coronary syndrome. However, little dosing information is available regarding the use of enoxaparin in patients with renal impairment. METHODS: We conducted a population pharmacokinetic analysis using anti-Xa activities measured in 532 patients (normal renal function in 34%, mild renal impairment in 36%, moderate renal impairment in 20%, and severe renal impairment in 10%) receiving subcutaneous enoxaparin (mean weight-corrected dose [+/-SD], 0.83 +/- 0.19 mg x kg(-1) x 12 h(-1) for an acute coronary syndrome. Simulations were then performed to develop a dosing strategy for patients with renal impairment. RESULTS: A 1-compartment model with first-order kinetics best fit the data. The covariate analysis showed that enoxaparin clearance was related to renal function and volume of distribution to total body weight. Enoxaparin clearance was decreased by 31% in patients with moderate renal impairment and by 44% in patients with severe renal impairment, resulting in a significant accumulation with the use of the standard 1 mg . kg(-1) x 12 h(-1) dosing regimen. Simulations showed that a first unadjusted dose of 1 mg/kg followed by a regimen of 0.8 mg . kg(-1) x 12 h(-1) in patients with moderate renal impairment or 0.66 mg . kg(-1) x 12 h(-)1 in patients with severe renal impairment should avoid accumulation of enoxaparin and keep peak anti-Xa activities between 0.5 and 1.2 IU/mL for a large majority of patients. CONCLUSIONS: An enoxaparin dosage reduction should be considered in acute coronary syndrome patients with creatinine clearance lower than 50 mL/min. A simple dosing protocol for enoxaparin to avoid significant accumulation in patients with moderate or severe renal impairment is proposed.

Effect of renal function on the pharmacokinetics of enoxaparin and consequences on dose adjustment.

The use of weight-adjusted enoxaparin dosage in patients with renal failure results in increased bleeding complications. The authors investigated the impact of patient-related factors such as renal function on the pharmacokinetics of enoxaparin. Anti-Xa activity was measured in the blood of 60 patients (74 +/- 10 years, body weight 72 +/- 15 kg, men 60%, creatinine clearance 56 +/- 24 mL/min) with acute coronary syndromes receiving subcutaneous administration of enoxaparin. A population-based approach with limited sampling strategy was used. A 1-compartment model with first-order absorption and elimination best fitted the data. The mean clearance (CL/F) and distribution volume (V/F) were 0.72 L/h and 6.65 L, respectively. V/F was influenced by body weight. CL/F was mainly related to the renal function, decreasing with increasing levels of serum creatinine, and lower in women than in men. The elimination half-life was thus estimated to be 6.4 and 9.2 hours in male and female patients, respectively. The final covariate submodel was then: [Equation included in full-text article]. Maximal anti-Xa activity was predicted to rise above 1.5 IU/mL in case of mild elevation of serum creatinine according to gender and body weight. Renal function is the main factor affecting enoxaparin pharmacokinetics. In patients with decreased renal function, enoxaparin dose should be adjusted on the basis of body weight, serum creatinine, and gender to reach a target anticoagulation level assessed by maximal anti-Xa activity in steady-state conditions.

Enoxaparin in unstable angina patients who would have been excluded from randomized pivotal trials.

OBJECTIVES: In the present study, we describe the characteristics and examine the anticoagulation levels and safety of subcutaneous enoxaparin in unstable angina (UA)/non-ST-segment elevation myocardial infarction (NSTEMI) patients who would not have been eligible in the Efficacy Safety Subcutaneous Enoxaparin in Non-Q-wave Coronary Events (ESSENCE) and Thrombolysis In Myocardial Infarction (TIMI)-11B trials. BACKGROUND: It is not known whether the benefit shown with enoxaparin in the selected population of pivotal trials can be extended to the real world. METHODS: In our center, all patients with UA/NSTEMI are anticoagulated with subcutaneous enoxaparin adjusted to creatinine clearance. Among 515 consecutive patients, we identified 174 who would not have been eligible for ESSENCE or TIMI-11B ("EP" group for excluded patients). We evaluated cardiovascular death or non-fatal myocardial infarction (MI), as well as major and minor bleeding events, at 30 days in the EP group and in patients without any of the exclusion criteria ("NEP" group for non-excluded patients). RESULTS: This EP group was older, had a higher female/male ratio, and more frequently had a history of MI or a diagnosis of non-Q MI on admission than the NEP group. The distribution of the anti-Xa activity was similar in both groups. The bleeding rates (major and minor) at 30 days were similar in the EP and NEP groups (2.3% vs. 2.9%, respectively, P = NS). On multivariate analysis, the use of glycoprotein IIb/IIIa inhibitors and the presence of hypertension were the only independent predictors of bleeding found in the whole population. Compared with the NEP group, the EP group had a fourfold increased rate of death or MI at 30 days (15.5% vs. 4.1%, p < 0.01). On multivariate analysis, the independent predictors of death or MI at 30 days were NSTEMI on admission, creatinine clearance, and heart failure. CONCLUSIONS: Patients who do not fit the enrollment criteria of ESSENCE/TIMI-11B have higher risk baseline characteristics for both bleeding and ischemic events. In these patients, enoxaparin with dose adjustment to creatinine clearance provides adequate anti-Xa levels and no excess of bleeding.

A unique, low dose of intravenous enoxaparin in elective percutaneous coronary intervention.

OBJECTIVES: This study was designed to examine a unique and low dose of intravenous enoxaparin in elective percutaneous coronary intervention (PCI) that would be applicable to an unselected population regardless of age, weight, renal function, or use of glycoprotein IIb/IIIa inhibitors. BACKGROUND: There is limited experience of anticoagulation using intravenous (IV) low-molecular-weight heparin in PCI, which has been obtained with high doses causing elevated anticoagulation levels and delayed sheath withdrawal. METHODS: A total of 242 consecutive patients undergoing elective PCI were treated with a single IV bolus of enoxaparin (0.5 mg/kg), and 26% of patients (n = 64) also received eptifibatide. Sheaths were removed immediately after the procedure in patients treated with enoxaparin only, and 4 h after the procedure in those also treated with eptifibatide. RESULTS: A peak anti-Xa >0.5 IU/ml was obtained in 97.5% of the population, and 94.6% of patients had their peak anti-Xa level in the predefined target range of 0.5 to 1.5 IU/ml. Advanced age, renal failure, being overweight, and eptifibatide use did not alter the anticoagulation profile. At one-month follow-up, six patients (2.5%) had died, had a myocardial infarction, or undergone an urgent revascularization; all the patients had an anti-Xa level >0.5 IU/ml during PCI. Patients without an ischemic event and without a creatine kinase rise, but with a detectable troponin release in the next 24 h of PCI (>2 microg/ml, n = 21), had similar anti-Xa levels as those without troponin elevation. There were one major and three minor bleeding events that were not associated with anti-Xa overshoot. CONCLUSIONS: Low-dose (0.5 mg/kg) IV enoxaparin allows a prespecified target level of anticoagulation (anti-Xa >0.5 IU/ml) in the vast majority of patients undergoing PCI, appears to be safe and effective, allows immediate sheath removal when used alone, and does not require dose adjustment when used with eptifibatide.