Which Therapy for Acute Heart Attacks? (The WEST Study)

Inclusion Criteria:

• Male or non-pregnant female patients aged >18 years
• Patients with symptoms presumed secondary to STEMI lasting at least 20 minutes and accompanied by ECG evidence >2 mm of ST elevation in 2 or more contiguous precordial leads or in 2 or more limb leads;or > 1mm ST elevation in 2 or more limb leads coupled with >1 mm ST depression in 2 or more contiguous precordial leads such that the total ST deviation is >4 mm; or presumed new left bundle branch block
• Earliest point of care and randomisation must be within 6 hours of onset of symptoms as defined in previous criteria
• Females of child-bearing age, not using a generally accepted method of contraception must have a negative urine pregnancy test
• Written informed consent prior to randomisation of study

Exclusion Criteria:

• PCI expected to commence within < 60 minutes from identification of suitable candidate
• Inability to have angiography/PCI within 3 hrs from randomisation
• Active bleeding or known hemorrhagic diathesis
• Any history of stroke, transient ischemic attack, dementia or structural CNS damage e.g. neoplasm, aneurysm, AV malformation
• Major surgery or trauma within the past 3 months
• Previous Coronary Artery Bypass Graft (CABG)
• Use of abciximab (ReoPro) or other GP IIb/IIIa antagonists within the preceding 7 days
• Any minor head trauma and/or any other trauma occurring after onset of the current myocardial infarction
• Significant hypertension (i.e. SBP > 180 mm HG and/or DBP > 110mm HG) at any time from presentation (earliest point of care) to randomisation
• Current treatment with vitamin K antagonist (warfarin) resulting with an INR > 1.5
• Anticipated difficulty obtaining vascular access
• Prolonged (>10 min) cardiopulmonary resuscitation or cardiogenic shock
• Patients who have participated in an investigational drug study within 7 days prior to randomisation
• Known renal insufficiency (prior creatinine >2.5 mg% for men and >2.0 mg% for women)
• Treatment with standard unfractionated heparin (heparin sodium) >5000 IU or a therapeutic dose of any low molecular weight heparin, within 6 hours prior to randomisation
• Known thrombocytopenia (prior platelet count below 100 000/ul)
• Known sensitivity to TNKase, clopidogrel, heparin, low molecular weight heparin or abciximab
• Pregnancy or lactation, parturition within the previous 30 days
• Any serious concomitant systemic or life limiting disorder that would be incompatible with the trial
• Inability to follow protocol and comply with follow-up requirements