Enoxaparin prevents death and cardiac ischemic events in unstable angina/non-Q-wave myocardial infarction - Results of the thrombolysis in myocardialinfarction (TIMI) 11B trial

Background-Low-molecular-weight heparins are attractive alternatives to unf ractionated heparin (UFH) for management of unstable angina/non-Q-wave myoc ardial infarction (UA/NQMI). Methods and Results-Patients (n=3910) with UA/NQMI were randomized to intra venous UFH for greater than or equal to 3 days followed by subcutaneous pla cebo injections or uninterrupted antithrombin therapy with enoxaparin durin g both the acute phase (initial 30 mg intravenous bolus followed by injecti ons of 1.0 mg/kg every 12 hours) and outpatient phase (injections every 12 hours of 40 mg for patients weighing <65 kg and 60 mg for those weighing gr eater than or equal to 65 kg), The primary end point (death, myocardial inf arction, or urgent revascularization) occurred by 8 days in 14.5% of patien ts in the UFH group and 12.4% of patients in the enoxaparin group (OR 0.83; 95% CI 0.69 to 1.00; P=0.048) and by 43 days in 19.7% of the UFH group and 17.3% of the enoxaparin group (OR 0.85; 95% CI 0.72 to 1.00; P=0.048), Dur ing the first 72 hours and also throughout the entire initial hospitalizati on, there was no difference in the rate of major hemorrhage in the treatmen t groups. During the outpatient phase, major hemorrhage occurred in 1.5% of the group treated with placebo acid 2.9% of the group treated with enoxapa rin (P=0.021). Conclusions-Enoxaparin is superior to UFH for reducing a composite of death and serious cardiac ischemic events during the acute management of UA/NQMI patients without causing a significant increase in the rate of major hemor rhage. No further relative decrease in events occurred with outpatient enox aparin treatment, but there was an increase in the rate of major hemorrhage .