Purpose: The purpose of this study is to evaluate the impact of acute ST-segment elevation myocardial infarction (STEMI) and primary percutaneous coronary intervention (PCI) on circulating prolylcarboxypeptidase (PRCP) level and activity.

Inclusion Criteria:

• Admitted for primary PCI for STEMI involving the LAD within 12 hours of onset of symptoms. STEMI will be defined as typical ECG changes (ST segment elevation ≥2mm in 2 or more precordial leads) associated with acute chest pain or an elevation of cardiac enzymes;
• Age ≥18 years;
• Informed consent from subject or next of kin.

Exclusion Criteria:

• Nonischaemic Cardiomyopathy;
• Cardiac surgery planed in the 6 months;
• Mechanical complication of STEMI (ventricular septal rupture, free wall rupture, acute severe mitral regurgitation);
• Renal or hepatic failure;
• Malignancy, HIV, or central nervous system disorder;
• Cardiopulmonary resuscitation >15 min and compromised level of consciousness;
• Cardiogenic shock;
• Current participation in any research study involving investigational drugs or devices;
• No written consensus;
• Previous myocardial infarction.

Healthy subjects, consecutive patients with unstable angina, and those undergoing primary PCI for STEMI