The Investigators will test the hypothesis that MGuard net protective stent, the investigational device, would be superior to conventional revascularization strategy (i.e. bare-metal stenting plus manual thrombectomy), for STEMI patients undergoing urgent percutaneous coronary interventions.

Embolization of thrombotic debris still represents a complication for ST-elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary interventions (PCI).

Distal embolization may decrease coronary and myocardial reperfusion after PCI in STEMI setting.

Unfortunately, intracoronary filters present several important limitations limiting their use and their efficacy especially in presence of huge amount of thrombus. In this respect, recent trials investigated whether a default manual thrombectomy strategy before stenting would ameliorate angiographic as well as clinical outcomes for STEMI patients undergoing percutaneous revascularization.

Of note, the most of embolization occurs when guidewire, and thrombectomy device cross the thrombus, and after the stent has been implanted as a consequence of plaque prolapse through the stent struts.

MGuard net protective stent, the investigational device, is a bare-metal stent covered with a ultra-thin flexible polyethylene terephthalate (or Dacron) mesh sleeve, that is anchored to the external surface of the struts. This biocompatible fiber net (string diameter 10-22 μm) has minimal effects on the stents' trackability and deliverability. During stent deployment, the net stretches and slides over the expanding stent struts, trapping the thromboembolic debris underneath the fiber net and isolating the prothrombotic intima components from the blood stream.

This protocol will test the hypothesis that MGuard stent would be superior to conventional revascularization strategy (i.e. bare-metal stenting plus manual thrombectomy), for STEMI patients undergoing urgent PCI in terms of angiographic as well as clinical outcomes.

Inclusion Criteria:

• >/= 18-year-old patients, willing to participate the study, after informed consent signature
• Female not pregnant or potentially child-bearing
• > 1 mV ST segment elevation in two or more contiguous leads
• Acute MI lasting more than 30 minutes and less than 12 hours
• De novo acute MI
• Infarct related artery reference vessel diameter >/= 2.5 mm
• Patient suitable for stenting according to vessel and lesion features

Exclusion Criteria:

• Dual antiplatelet therapy contraindication
• Ischemic stroke less than 30 days or previous haemorrhagic stroke
• WBC count less than 1000 per mm3;
• Platelet count less than 50.000 per mm3
• Life expectancy less than 1 year
• Cardiogenic shock at admission
• Previous stented infarct related artery
• Stent thrombosis as the responsible for current STEMI
• Inability to identify infarct related artery
• True bifurcation lesion, or lesion near a side branch with a reference vessel diameter >/= 2.5 mm that could be diseased after stenting procedure
• LBBB
• Definitive pacing (or ECG abnormalities precluding ST-segment resolution evaluation
• Participation other study