Outcome of urgent and elective percutaneous coronary interventions after pharmacologic reperfusion with tenecteplase combined with unfractionated heparin, enoxaparin, or abciximab.
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OBJECTIVES: The aim of this study was to evaluate percutaneous coronary intervention (PCI) in the Assessment of the Safety and Efficacy of New Thrombolytic Regimens (ASSENT-3) trial. BACKGROUND: In the ASSENT-3 trial, co-therapy with abciximab (ABC) or enoxaparin (ENOX) reduced ischemic complications after ST-elevation acute myocardial infarction treated with tenecteplase when compared with unfractionated heparin (UFH). The effect of these new co-therapies on the results of PCI is unknown. METHODS: Clinical outcomes in patients who received co-therapy with ABC, ENOX, or UFH and subsequently underwent an elective (n = 1,064) or urgent (n = 716) PCI in the ASSENT-3 trial were compared. RESULTS: No significant differences in clinical end points were observed in patients who underwent an elective PCI. A non-significant trend toward fewer in-hospital myocardial re-infarctions was seen with ABC and ENOX when compared with UFH (0.5% vs. 0.6% vs. 1.5%, respectively). The incidence of bleeding complications was similar in the three treatment arms. Significantly fewer ABC- and ENOX-treated patients needed urgent PCI compared with UFH (9.1% vs. 11.9% vs. 14.3%; p < 0.0001), but outcomes in these patients were in general less favorable (30-day mortality: 8.2% vs. 5.4% vs. 4.5%; 1-year mortality: 11.0% vs. 8.5% vs. 5.6%; in-hospital re-infarction: 3.9% vs. 2.5% vs. 2.7%; major bleeding complications: 8.8% vs. 7.0% vs. 3.4%). In pairwise comparisons with UFH, the higher one-year mortality and major bleeding rates after ABC were statistically significant (p = 0.045 and p = 0.012, respectively). CONCLUSIONS: Clinical outcomes after elective PCI were similar with the three antithrombotic co-therapies studied in ASSENT-3. Although fewer patients needed urgent PCI with ABC and ENOX, clinical outcomes were less favorable in this selected population, especially with ABC. (+info)
Pharmacokinetics of the low molecular weight heparin enoxaparin during 48 h after bolus administration as an anticoagulant in haemodialysis.
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BACKGROUND: The interest of low molecular weight heparins (LMWH) regarding bleeding risk is controversial in renal failure patients. In haemodialysis patients, there are very few data on the pharmacokinetics of LMWH after the end of the session. The aim of the study was to evaluate the duration of anticoagulation after bolus administration of the LMWH enoxaparin at the start of haemodialysis. METHODS: The pharmacokinetics of enoxaparin were studied during the 48 h following a single bolus injection at the start of the dialysis session in 30 chronic haemodialysis patients. Pharmacokinetics were determined using a population approach (Non Linear Mixed Effects Modelling). RESULTS: A single injection of enoxaparin at 60 U IU/kg (4000 +/- 455 IU) led to an anti-Xa activity higher than 1.2 IU/ml during the first 2 h of the session, and between 0.4 and 1.2 IU during the third and fourth hours. After the end of the session, anti-Xa activity remained higher than 0.4 IU/ml up to 10 h after injection, and higher than 0.1 IU/ml up to 24 h. The pharmacokinetic model showed that only weight improved the predicted vs observed anti-Xa activity plot. The model was used to simulate single and multiple dosing with decreased enoxaparin doses. Whatever the procedure, anti-Xa activity remained high (>0.22 +/- 0.99 UI/ml) up to 12 h after the start of the dialysis session. CONCLUSIONS: These results suggest that haemodialysis patients receiving the LMWH enoxaparin during dialysis are at risk of bleeding up to 10 h after the injection. (+info)
Enoxaparin for the treatment of acute myocardial infarction with persistent ST-segment elevation.
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Enoxaparin (E) is a low-molecular-weight heparin which has been proven more effective than unfractionated heparin (UFH) for the treatment of non-ST-segment elevation acute coronary syndromes. Limited and inconclusive on the other hand, are the data on the use of E in acute myocardial infarction with persistent ST-segment elevation (STEAMI). Therefore, we performed a review of the literature in order to evaluate the level of evidence relative to the efficacy and safety of E in such a clinical setting. The effect of E in STEAMI has been evaluated in 7 clinical studies, including a total of about 9500 patients. Compared to placebo, E resulted more effective on the incidence of the combined end-point of death, re-infarction and recurrent angina in the study by Glick et al. and on the patency of the infarct-related artery in the AMI-SK study. Compared to UFH, E resulted more effective on the incidence of the combined end-point of death, reinfarction and unstable angina in the study by Baird et al. and of in-hospital re-infarction and refractory ischemia rates in both ASSENT-3 and ASSENT-3 PLUS, while the effect on the patency of the infarct-related artery, which was evaluated in HART-II and ENTIRE-TIMI 23, resulted non univocal. Overall, bleeding complications were more frequent than with placebo and comparable to UFH, with the exception of ASSENT-3 PLUS where pre-hospital administration of E was associated with a doubled incidence of intracranial bleeding (although only in patients older than 75 years). In conclusion, the administration of E, in association with aspirin and thrombolytics, already appears a possible therapeutic option for the treatment of STEAMI, due to its good efficacy and safety profile, along with its easiness of use. However, prior to have its use recommended, the current B level of evidence of a superior efficacy and safety compared to UFH needs to be reinforced. Further-more, some open issues relative to the use of E in particular settings (aged patients, in association with glycoprotein IIb/IIIa inhibitors and during percutaneous coronary revascularization) need to be clarified. (+info)
The safety and efficacy of subcutaneous enoxaparin versus intravenous unfractionated heparin and tirofiban versus placebo in the treatment of acute ST-segment elevation myocardial infarction patients ineligible for reperfusion (TETAMI): a randomized trial.
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OBJECTIVES: The aims of the Safety and Efficacy of Subcutaneous Enoxaparin Versus Intravenous Unfractionated Heparin and Tirofiban Versus Placebo in the Treatment of Acute ST-Segment Elevation Myocardial Infarction Patients Ineligible for Reperfusion (TETAMI) study were to demonstrate that enoxaparin was superior to unfractionated heparin (UFH) and that tirofiban was better than placebo in patients with acute ST-segment elevation myocardial infarction (STEMI) who do not receive timely reperfusion. BACKGROUND: An optimal treatment strategy has not been identified for the many STEMI patients ineligible for acute reperfusion. METHODS: A total of 1224 patients were enrolled in 91 centers in 14 countries between July 1999 and July 2002. Patients with STEMI ineligible for reperfusion were randomized to enoxaparin, enoxaparin plus tirofiban, UFH, or UFH plus tirofiban. All patients received oral aspirin. The primary efficacy end point was the 30-day combined incidence of death, reinfarction, or recurrent angina; the primary analysis was the comparison of the pooled enoxaparin and UFH groups. RESULTS: The incidence of the primary efficacy end point was 15.7% enoxaparin versus 17.3% for UFH (odds ratio 0.89 [95% confidence interval CI = 0.66 to 1.21]) and 16.6% for tirofiban versus 16.4% for placebo (odds ratio 1.02 [95% CI 0.75 to 1.38]). The Thrombolysis In Myocardial Infarction (TIMI) major hemorrhage rate was 1.5% for enoxaparin versus 1.3% for UFH (odds ratio 1.16 [95% CI 0.44 to 3.02]) and 1.8% versus 1% for tirofiban versus placebo (odds ratio 1.82 [95% CI 0.67 to 4.95]). CONCLUSIONS: This study did not show that enoxaparin significantly reduced the 30-day incidence of death, reinfarction, and recurrent angina compared with UFH in non-reperfused STEMI patients. However, enoxaparin appears to have a similar safety and efficacy profile to UFH and may be an alternative treatment. Additional therapy with tirofiban did not appear beneficial. (+info)
Novel concatameric heparin-binding peptides reverse heparin and low-molecular-weight heparin anticoagulant activities in patient plasma in vitro and in rats in vivo.
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Patients given unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) for prophylaxis or treatment of thrombosis sometimes suffer serious bleeding. We showed previously that peptides containing 3 or more tandem repeats of heparin-binding consensus sequences have high affinity for LMWH and neutralize LMWH (enoxaparin) in vivo in rats and in vitro in citrate. We have now modified the (ARKKAAKA)(n) tandem repeat peptides by cyclization or by inclusion of hydrophobic tails or cysteines to promote multimerization. These peptides exhibit high-affinity binding to LMWH (dissociation constant [K(d)], approximately 50 nM), similar potencies in neutralizing anti-Factor Xa activity of UFH and enoxaparin added to normal plasma in vitro, and efficacy equivalent to or greater than protamine. Peptide (ARKKAAKA)(3)VLVLVLVL was most effective in all plasmas from enoxaparin-treated patients, and was 4- to 20-fold more effective than protamine. Several other peptide structures were effective in some patients' plasmas. All high-affinity peptides reversed inhibition of thrombin-induced clot formation by UFH. These peptides (1 mg/300 g rat) neutralized 1 U/mL anti-Factor Xa activity of enoxaparin in rats within 1 to 2 minutes. Direct blood pressure and heart rate measurements showed little or no hemodynamic effect. These heparin-binding peptides, singly or in combination, are potential candidates for clinical reversal of UFH and LMWH in humans. (+info)
Prospective evaluation of clinical outcomes after acute ST-elevation myocardial infarction in patients who are ineligible for reperfusion therapy: preliminary results from the TETAMI registry and randomized trial.
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BACKGROUND: Treatment with lytics or primary percutaneous coronary interventions (PCI) reduces the mortality rate of patients with ST-elevation myocardial infarction (STEMI) presenting within 12 hours. Patients presenting >12 hours are generally considered to be ineligible for reperfusion therapy, and there are currently no specific treatment recommendations for this subgroup.Methods- All patients with STEMI <24 hours were included in the Treatment with Enoxaparin and Tirofiban in Acute Myocardial Infarction (TETAMI) randomized trial or registry. Those patients who were ineligible for acute reperfusion, had no cardiogenic shock, and were not planned for revascularization within 48 hours were randomized to 1 of 4 antithrombotic regimens involving enoxaparin or unfractionated heparin (UFH), in combination with tirofiban or placebo for 2 to 8 days. A concurrent registry tracked STEMI patients coming in within <12 hours, and who underwent reperfusion. This registry also tracked the remaining STEMI patients who neither received reperfusion nor were enrolled in the TETAMI randomized trial. The demographics and clinical outcomes of all three groups (received reperfusion therapy, too late for reperfusion and enrolled in the randomized trial, neither received reperfusion therapy nor were enrolled in the randomized trial) were prospectively tracked. RESULTS AND CONCLUSIONS: There were 2,737 patients who presented with STEMI or a new left branch bundle block (LBBB), of which 1,654 (60%) presented < or =12 hours. There were 1,196 (72%) of 1,654 patients who received reperfusion therapy. There were 458 (28%) of the 1,654 patients deemed "ineligible" for reperfusion, mostly because of a contraindication to lytics or for being "too old." In contrast, 1,083 (40%) of 2,737 patients presented >12 hours. Apart from 34 of these patients who had a stuttering infarction and were referred for reperfusion, the remaining patients did not receive reperfusion therapy. Registry patients who received reperfusion therapy, compared with TETAMI randomized patients (all of whom received antithrombotic therapy) and registry patients who did not receive reperfusion, were younger (61 years versus 63 years and 67 years), were more likely to be male (78% versus 73% and 63%), and had persistent ST-segment elevation as opposed to LBBB or Q waves. Registry patients who received reperfusion therapy had better clinical outcomes, even after adjusting for admission Killip class, compared with TETAMI randomized patients and registry patients who did not receive reperfusion therapy. TETAMI randomized patients had better outcomes than registry patients who did not receive reperfusion therapy. The major obstacle to expanding the delivery of reperfusion therapy to patients with STEMI is the large fraction of patients who present too late for reperfusion therapy. Examination of prospectively gathered data on STEMI patients who are ineligible for reperfusion may help optimize their treatment. (+info)
Comparative analysis of procoagulatory activity of haemodialysis, haemofiltration and haemodiafiltration with a polysulfone membrane (APS) and with different modes of enoxaparin anticoagulation.
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BACKGROUND: Treatment modalities of renal replacement therapy differ in their diffusive and convective mass transfer characteristics. It was the goal of this study to clarify whether an increase in convective mass transfer as performed with haemofiltration (HF) and haemodiafiltration (HDF) in comparison with high-flux haemodialysis (HD) is associated with an alteration in procoagulatory activity or with complement activation. METHODS: Ten stable chronic HD patients were monitored during 120 treatments in a randomized cross over design. A high-flux polysulfone dialyser (APS 900) was used for high-flux HD, pre-dilution HF and pre-dilution HDF. Constant flow of on-line substitution fluid for HF and HDF was 200 ml/min. The low molecular weight heparin (LMWH) enoxaparin was used for anticoagulation (i) as single bolus (50 IU/kg body weight, median 3700 IU) and (ii) as bolus of 1200 IU followed by a median continuous dose of 400 IU/h. Blood samples were collected before the LMWH bolus, after 10 min, 60 min, 120 min and at the end of treatment in venous and arterial blood lines to determine antiXa activity, thrombin-antithrombin-III complex (TAT), D-dimer and C5a generation. RESULTS: Net ultrafiltration did not significantly differ between HD, HF and HDF but total ultrafiltration in HF and HDF far exceeded total ultrafiltration in HD. With conditions of single bolus, or bolus and continuous anticoagulation with enoxaparin, after comparable treatment times (median duration 4.25 h), TAT and D-dimer generation at identical anti-Xa levels revealed significantly higher coagulation activity during HF and HDF, compared with high-flux HD as assessed by comparative area under the curve (AUC) analysis. Plasma concentration of C5a in venous bloodlines did not significantly differ during HD, HF and HDF. CONCLUSION: A higher convective mass transfer during HF and HDF, in comparison with high-flux HD caused by a greater total ultrafiltration volume was associated with increased procoagulatory activity in the extracorporeal circuit. Molecular markers assessing the activation of coagulation are appropriate to adjust the anticoagulation regime to high UF volumes in order to minimize bleeding risk and optimize patency of the extracorporeal circuit. (+info)
Recurrent cardiac ischemic events early after discontinuation of short-term heparin treatment in acute coronary syndromes: results from the Thrombolysis in Myocardial Infarction (TIMI) 11B and Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-Wave Coronary Events (ESSENCE) studies.
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OBJECTIVES: The aim of this study was to determine whether discontinuation of low-molecular-weight heparin (LMWH) treatment results in a clustering of cardiac ischemic events as previously observed after cessation of unfractionated heparin (UFH) in acute coronary syndrome (ACS) patients. BACKGROUND: Clinical trials in patients with ACS have shown early recurrent ischemic events after discontinuation of UFH treatment. We analyzed whether LMWH cessation also results in early ischemic recurrence events and if continuation of a fixed-dose LMWH prevents this complication. METHODS: The combined incidence of death, myocardial infarction, or urgent revascularization in the first seven days after discontinuation of UFH (n = 3,012), short-term enoxaparin 1 mg/kg subcutaneously twice a day (n = 2,011), and short-term enoxaparin followed by prolonged enoxaparin 60 mg subcutaneously twice a day (n = 1,075) was analyzed from the combined Thrombolysis In Myocardial Infarction (TIMI) 11B/Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-Wave Coronary Events (ESSENCE) database in a per patient analysis. RESULTS: The cessation of both UFH and short-term enoxaparin resulted in a similar clustering of recurrent ischemic events on the first day, with an incidence of the primary end point of 2.8% in both groups. Of all recurrent events in the first week after cessation, 40% occurred in the first 24 h. The continuation of a fixed-dose enoxaparin treatment prevented this early excess, with a first day incidence of 0.4% (p < 0.0001). The TIMI risk score characteristics predicted the incidence of early rebound ischemic events. CONCLUSIONS: There is significant clustering of recurrent ischemic events within 24 h after cessation of both short-term UFH and enoxaparin treatment, and patients should be carefully monitored during that period. This early rebound may be prevented by continuation of a fixed dose of enoxaparin. (+info)