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