To evaluate whether ANP as an adjunctive therapy for AMI reduces myocardial infarct size and improves regional wall motion.

The benefits of percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) are limited by reperfusion injury. In animal models, atrial natriuretic peptide (ANP) reduces infarct size, so the Japan-Working groups of acute myocardial Infarction for the reduction of Necrotic Damage by ANP(J-WINDANP) designed a prospective, randomized, multicenter study, to evaluate whether ANP as an adjunctive therapy for AMI reduces myocardial infarct size and improves regional wall motion.

Twenty hospitals in Japan will participate in the J-WIND-ANP study. Patients with AMI who are candidates for PCI are randomly allocated to receive either intravenous ANP or placebo administration. The primary end-points are (1) estimated infarct size (Σcreatine kinase and troponin T) and (2) left ventricular function (left ventriculograms). Single nucleotide polymorphisms (SNPs) that may be associated with the function of ANP and susceptibility of AMI will be examined. Furthermore, a data mining method will be used to design the optimal combinational therapy for post-MI patients.

J-WIND-ANP will provide important data on the effects of ANP as an adjunct to PCI for AMI and the SNPs information will open the field of tailor-made therapy. The optimal therapeutic drug combination will also be determined for post-MI patients.

Inclusion Criteria:

1. Age 20-79 years
2. Chest pain of more than 30 min
3. 0.1 mV ST-segment elevation in 2 contiguous ECG leads
4. Admission to hospital within 12 h of symptom onset
5. First episode of AMI
6. Candidates for PCI

Exclusion Criteria:

1. History of old myocardial infarction
2. Left main coronary artery stenosis
3. Severe liver and/or kidney dysfunction
4. Suspected aortic dissection
5. History of coronary artery bypass graft
6. History of allergic response to drugs
7. Severe hypovolemia
8. Right ventricular infarction