Thrombolysis in Patients With Unstable Angina Improves the Angiographic but Not the Clinical Outcome - UNASEM


The goal of this multicenter, randomized, placebo-controlled trial was to evaluate the angiographic and clinical outcomes of treatment with the thrombolytic anistreplase among patients with unstable angina.


Thrombolytic therapy may improve clinical and angiographic outcomes among patients with unstable angina.

Study Design

Study Design:

Patients Enrolled: 159
Mean Patient Age: Mean of 57/59 in the intervention/placebo
Female: ~40

Patient Populations:

  • Age 30-70
  • Resting heart rate 50-100
  • Typical history of unstable angina by the Canadian Cardiovascular Society criteria
  • Last episode within 12 hours prior to admission
  • ST depression in two or more inferior leads or three or more precordial leads of at least 0.1 mV, or terminal negative T waves with minimal depth of 0.2 mV in two or more leads


  • Previous myocardial infarction, percutaneous transluminal coronary angioplasty, or any cardiac surgery
  • Left bundle branch block or accessory bypass tract
  • Left ventricular hypertrophy
  • Use of digitalis with resulting ECG changes
  • Presence of a pacemaker
  • "One hour after admission in the absence of chest pain"
  • Arrhythmia-induced ST-T changes
  • Systolic pressure over 190 or diastolic pressure over 110 within six months of admission
  • Known renal insufficiency
  • Severe valvular disease
  • Class III or IV New York Heart Association heart failure
  • Cardiomyopathy or "any severe concomitant disease"
  • Treatment with streptokinase or anistreplase within one year of admission
  • Aspirin dosage above 1000 mg/day
  • Oral anticoagulant or IV heparin use
  • Recent major surgery, gastrointestinal ulcer bleeding, or genitourinary tract bleeding within three months of admission
  • History of cerebrovascular accident of any kind
  • Recent trauma or cardiac resuscitation
  • Intramuscular injection given within the past 72 hours
  • Bleeding diathesis
  • Diabetic retinopathy, pregnancy, or menstruation
  • Anticipated difficulty with regard to cardiac catheterizations

Primary Endpoints:

Change in coronary artery lesion diameter between the initial and repeat (after 12-28 hours) coronary angiograms

Secondary Endpoints:

  • Mortality, myocardial infarction, recurrent angina, angioplasty, or bypass surgery
  • Major bleeding requiring blood transfusion
  • Overall bleeding

Drug/Procedures Used:

  • 30 U anistreplase
  • Placebo
After randomization, anistreplase was not given if initial angiography demonstrated no coronary lesion greater than 50%, significant left main disease, or if there was interval development of myocardial infarction.

Concomitant Medications:

  • IV nitroglycerin
  • Heparin bolus of 5000 IU, followed by infusion 1000 IU/h titrate to partial thromboplastin time 1.5-2.5x control values
  • Beta-blockers or calcium blockers
  • Aspirin 300 mg/day

Principal Findings:

  • Administration of anistreplase was associated with an 11% decrease in percent diameter stenosis compared with a 3% decrease with placebo (p=0.002).
  • There was no significant difference in measured clinical outcomes.
  • Administration of anistreplase was significantly associated with higher rates of bleeding (26% vs. 9%, p=0.001) and with higher rates of major bleeding (9% vs. 1%).


Among patients with unstable angina with no history of significant heart disease, the administration of 30 U anistreplase was associated with a significant improvement in percent diameter stenosis at the expense of higher rates of bleeding compared with placebo. There was no association between administration of anistreplase and improved clinical outcomes.


Bar FW, Verheugt FW, Col J, et al. Thrombolysis in patients with unstable angina improves the angiographic but not the clinical outcome. Results of UNASEM, a multicenter, randomized, placebo-controlled, clinical trial with anistreplase. Circulation 1992;86:131-7.

Clinical Topics: Anticoagulation Management, Dyslipidemia, Lipid Metabolism, Novel Agents

Keywords: Thrombolytic Therapy, Myocardial Infarction, Heparin, Constriction, Pathologic, Fibrinolytic Agents, Heart Rate, Calcium, Partial Thromboplastin Time, Anistreplase, Nitroglycerin

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