Low molecular weight heparin versus regular heparin or aspirin in the treatment of unstable angina and silent ischemia (original) (raw)
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Clinical Cardiology, 1999
Buckground: Unstable angina is an active thrombotic process that involves thrombus formation and platelets. It requires a rapid and intensive treatment with anticoagulants and antiplatelets. Hypothesis: The aim of the present study was to compare the efficacy of a very low molecular weight heparin, OP 2000, with standard heparin in the treatment of unstable angina. Tolerance and safety were also assessed. Methocls: The study population included 120 consecutive hospitalized patients with unstable angina randomized for treatment with very low molecular weight heparin or with standard heparin. The dosage of the study drug was 200 mg intramuscular (IM) the first day followed by 150 mg M d a y. The control drug was standard heparin starting at a dosage of 5,000 UVml intravenously (IV) and followed by continuous infusion at an activated partial thromboplastin time-adjusted dosage. The primary end points were death, acute myocardial infarction, urgent revascularization, and recurrence of angina. Tolerability was assessed using bleeding parameters, thrombocytopenia, and allergic reactions. Results: Fourteen clinical events were reported in the study group compared with 25 events in the control group (p < 0.05). No adverse events were reported in either group. Conclusion: During the acute phase of unstable angina, treatment with a very low molecular weight heparin plus aspirin was more effective than treatment with standard heparin plus aspirin.
The New England Journal of Medicine, 1997
Background Antithrombotic therapy with heparin plus aspirin reduces the rate of ischemic events in patients with unstable coronary artery disease. Lowmolecular-weight heparin has a more predictable anticoagulant effect than standard unfractionated heparin, is easier to administer, and does not require monitoring. Methods In a double-blind, placebo-controlled study, we randomly assigned 3171 patients with angina at rest or non-Q-wave myocardial infarction to receive either 1 mg of enoxaparin (low-molecular-weight heparin) per kilogram of body weight, administered subcutaneously twice daily, or continuous intravenous unfractionated heparin. Therapy was continued for a minimum of 48 hours to a maximum of 8 days, and we collected data on important coronary end points over a period of 30 days. Results At 14 days the risk of death, myocardial infarction, or recurrent angina was significantly lower in the patients assigned to enoxaparin than in those assigned to unfractionated heparin (16.6 percent vs. 19.8 percent, P ϭ 0.019). At 30 days, the risk of this composite end point remained significantly lower in the enoxaparin group (19.8 percent vs. 23.3 percent, P ϭ 0.016). The need for revascularization procedures at 30 days was also significantly less frequent in the patients assigned to enoxaparin (27.0 percent vs. 32.2 percent, P ϭ 0.001). The 30-day incidence of major bleeding complications was 6.5 percent in the enoxaparin group and 7.0 percent in the unfractionated-heparin group, but the incidence of bleeding overall was significantly higher in the enoxaparin group (18.4 percent vs. 14.2 percent, P ϭ 0.001), primarily because of ecchymoses at injection sites. Conclusions Antithrombotic therapy with enoxaparin plus aspirin was more effective than unfractionated heparin plus aspirin in reducing the incidence of ischemic events in patients with unstable angina or non-Q-wave myocardial infarction in the early phase. This benefit of enoxaparin was achieved with an increase in minor but not in major bleeding. (N Engl
Current Therapeutic Research, 1995
Several studies have shown conflicting effects of thrombolysis in patients with unstable angina. In these trials the time between presentation with chest pain and randomization was long (12 hours to 3 days). This study compared thrombolysis and heparin with heparinalone treatment in patients in the acute phase of unstable angina. One hundred fifty-three consecutive patients hospitalized with chest pain at rest (first episode) lasting >5 minutes but <30 minutes, electrocardiographic (ECG) evidence of ischemia, echocardiographic alterations, and angina unresponsive to intravenous nitrates were randomized in a single-blind manner to one of two groups. Group A (n --77) received thrombolysis (recombinant tissue-type plasminogen activator
Low-molecular-weight heparins in non–ST-segment elevation ischemia: the ESSENCE trial
The American Journal of Cardiology, 1998
for the ESSENCE Study Group Combination antithrombotic therapy with heparin plus aspirin decreases the risk of recurrent ischemic events in patients with acute coronary syndromes without persistent ST-segment elevation. Compared with standard unfractionated heparin, low-molecular-weight heparin (LMWH) has a more predictable antithrombotic effect, is easier to administer, and does not require coagulation monitoring. At 176 hospitals in 3 continents, 3,171 patients with rest unstable angina or non-Q-wave myocardial infarction were randomly assigned to either enoxaparin (a LMWH), 1 mg/kg twice daily subcutaneously, or to continuous intravenous unfractionated heparin, for a minimum of 48 hours to a maximum of 8 days. Trial medication was administered in a doubleblind, placebo-controlled fashion. At 14 days, the primary endpoint, the composite risk of death, myocardial infarction, or recurrent angina with electrocardiographic changes or prompting intervention, was significantly lower in patients assigned to enoxaparin compared with heparin (16.6% vs 19.8%; odds ratio [OR] 1.24; 95% confidence interval [CI] 1.04-1.49; p ؍ 0.019). At 30 days, the composite risk of death, myocardial infarction, or recurrent angina remained significantly lower in the enoxaparin group compared with the unfractionated heparin group (19.8% vs 23.3%, OR 1.23; 95% CI 1.0-1.46, p ؍ 0.016). The rate of revascularization procedures at 30 days was also significantly lower in patients assigned to enoxaparin (27.1% vs 32.2%, p ؍ 0.001). The 30-day incidence of major bleeding complication was 6.5% versus 7.0% (p ؍ not significant), but the incidence of minor bleeding was significantly higher in the enoxaparin group (13.8% vs 8.8%, p <0.001) due primarily to injection-site ecchymosis. Thus, combination antithrombotic therapy with enoxaparin plus aspirin is more effective than unfractionated heparin plus aspirin in decreasing ischemic outcomes in patients with unstable angina or non-Q-wave myocardial infarction in the early (30 days) phase. The lower recurrent ischemic event rate seen with the LMWH, enoxaparin, is achieved without an increase in major bleeding, but with an increase in minor bleeding complications due mainly to injection-site ecchymosis. ᮊ1998 by Excerpta Medica, Inc.
Unfractionated heparin (UFH) and low-molecularweight heparins (LMWHs) are widely used in curative and preventive treatments of thromboembolic disorders. The aim of the study was to investigate factors associated with the choice of these types of heparin to treat patients with unstable angina under real conditions of hospital use. A cross-sectional study was performed in a private general hospital in Belo Horizonte, Brazil, from January 1st to December 31th, 2001. Data were collected from the hospital electronic database. Inpatients with angina who received enoxaparin or UFH were included in the survey. Data for 555 patients were recorded, including 401 treated with enoxaparin and 154 with UFH. Univariate analysis showed that male and elderly people predominated in both groups, with no statistical difference in the proportions (p>0.05). Multivariate analysis showed 4 factors associated with the use of enoxaparin: cardiac revascularization surgery (OR=0.434), arrhythmias (OR=9.343)...
Low molecular weight heparins versus unfractionated heparin for acute coronary syndromes
Cochrane Database of Systematic Reviews, 2003
Characteristics of included studies Study ESSENCE 1997 Methods Design: Prospective, randomized, double-blind, parallel-group, multicenter trial Randomisation: not described. Blinding: double dummy trial, dummy heparin results, similar appearance of drug. Number excluded: not reported. Withdrawals: 367 (11.6%) all well documented and evenly balanced. Baseline characteristics: no imbalance demonstrated; adjusted analyses performed. Participants Location: 176 hospitals in 10 countries (North America, South America and Europe). Participants: 3171 patients 18 years of age or older. Unstable angina: Recent onset of angina at rest lasting at least 10 minutes and occurring within 24h before randomization. In addition, had to have one of the following three: ECG changes, previous MI or revascularization procedure, or invasive/noninvasive testing suggestive of ischemic heart disease. Non-Q wave MI: not included Exclusion criteria: left bundle branch block, pacemaker, persistent ST segment elevation, angina with established precipitating cause, contra-indications to anticoagulation, creatinine clearance < 30 ml/min. Interventions Intervention: ASA 100-325 mg/d, enoxaparin 100 anti-factor Xa units/kg sc bid, placebo bolus and infusion. Control: ASA 100-325 mg/d, UFH 5000 IU iv then drip to keep PTT between 55-85 seconds. Timing: Trial therapy was administered for a minimum of 48h to a maximum of 8 days. Co-interventions: not permitted; patients excluded if treating MD deviated from protocol. Other co-interventions (e.g., oxygen, beta-blockers, nitroglycerine, etc) not well described. Outcomes Acute Coronary Events: Recurrent angina, MI, death all reported. Urgent revascularization: reported End Point Definition: Triple end point for all cardiovascular events (angina, MI, death). Complication: Major bleeding, minor bleeding, and thrombocytopenia. Timing of assessment: Outcomes at 48h, 14 days, and 30 days. Notes Enoxaparin. We used the outcomes reported at 14 days for the pooled results. Correspondence with Pharmaceutical Company. Allocation concealment B Study FRAXIS 1999 Methods Prospective, randomized, double-blind, parallel-group, multicenter trial. Participants Patients 18 years of age or older with non-Q-wave MI or recent onset of rest angina lasting longer than 5 minutes or severe exertional angina and occurring within 48h before randomization. In addition, had to have ECG signs compatible with the clinical diagnosis or in cases of preexisting and documented LBBB, known CAD. If Q waves were present, a previous ECG tracing must confirm the long standing diagnosis. Interventions Group I: ASA 325 mg/d, UFH 5000 IU iv then infusion titrated to PTT x 6 days. Group II: ASA 325 mg/d, nadroparin iv 86 AXa IU/kg then sc 86 AXa IU/kg bid x 6 days. Group III: ASA 325 mg/d, nadroparin iv 86 AXa IU/kg then sc 86 AXa IU/kg bid x 14 days. 11 Low molecular weight heparins versus unfractionated heparin for acute coronary syndromes (Review)