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 andaccompanied by ECG evidence >2 mm of ST elevation in 2 or more contiguous precordialleads or in 2 or more limb leads;or > 1mm ST elevation in 2 or more limb leads coupledwith >1 mm ST depression in 2 or more contiguous precordial leads such that the totalST 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 symptomsas defined in previous criteria

• Females of child-bearing age, not using a generally accepted method of contraceptionmust 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 damagee.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 currentmyocardial infarction

• Significant hypertension (i.e. SBP > 180 mm HG and/or DBP > 110mm HG) at any time frompresentation (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 torandomisation

• 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 atherapeutic dose of any low molecular weight heparin, within 6 hours prior torandomisation

• Known thrombocytopenia (prior platelet count below 100 000/ul)

• Known sensitivity to TNKase, clopidogrel, heparin, low molecular weight heparin orabciximab

• Pregnancy or lactation, parturition within the previous 30 days

• Any serious concomitant systemic or life limiting disorder that would be incompatiblewith the trial

• Inability to follow protocol and comply with follow-up requirements