• MI size at 48-72 hours [ Time Frame: 48-72 hours ] [ Designated as safety issue: No ]
• MI size normalized to area at risk [ Time Frame: 48-72 hours ] [ Designated as safety issue: No ]
• myocardial perfusion at coronary angiography [ Time Frame: at completion of PCI ] [ Designated as safety issue: No ]
• Infarct transmurality [ Time Frame: 48-72 hours and 4 months ] [ Designated as safety issue: No ]
• global & regional LV function and LV mass [ Time Frame: 48-72 hours and 4 months ] [ Designated as safety issue: No ]
• change in global LV function and mass [ Time Frame: between 48-72 hours and 4 months ] [ Designated as safety issue: No ]
• MI size as a fraction of LV size [ Time Frame: 4 months ] [ Designated as safety issue: No ]
• Resolution of ST segment elevation compared with that observed at enrollment [ Time Frame: 4 hours ] [ Designated as safety issue: No ]
• Troponin T levels and CPK-MB area under the curve [ Time Frame: 48 hours ] [ Designated as safety issue: No ]
• Change in adverse remodeling parameters compared with 48-72 hrs: Changes in LV end-diastolic vol, end-systolic vol, end-diastolic myocardial wall thickness in infarct, peri-infarct and remote areas, and in sphericity index at end-diastole and end-systole [ Time Frame: 4 months ] [ Designated as safety issue: No ]

The purpose of this study is to assess whether or not inhaled nitric oxide can decrease myocardial infarction (MI) size at 48-72 hours in patients presenting with an ST segment elevation MI who undergo successful percutaneous coronary intervention.

The purpose of the trial is to assess whether or not inhaled nitric oxide can decrease myocardial infarction (MI) size as a fraction of left ventricular (LV) size at 48-72 hours in patients presenting with an ST segment elevation MI who undergo successful percutaneous coronary intervention (PCI).

The primary endpoint for this study will be myocardial infarction size as a fraction of left ventricular size at 48-72 hours as measured by contrast-enhanced cardiac MRI.

• Acute Myocardial Infarction
• ST Elevation MI
• STEMI

Inclusion Criteria:

• Acute myocardial infarction and electrocardiographic evidence of ST elevation
• No clinical evidence of congestive heart failure
• All patients must undergo successful percutaneous coronary intervention for TIMI 0 or 1 coronary flow with resulting TIMI 2 or 3 flow
• Greater than 18 years of age
• Signed IRB approved informed consent

Exclusion Criteria:

• Prior myocardial infarction
• Requirement for urgent cardiac surgery
• Previous CABG or PCI
• Left bundle branch block
• Heart block that is expected to require a temporary pacemaker for greater than 72 hours
• Prior use of thrombolytic therapy for the current event
• Unable to tolerate magnetic resonance imaging or unable to tolerate gadolinium contrast media, including patients with a calculated creatinine clearance less than 60ml/min/1.73m² BSA
• Active or recent hemorrhage requiring an invasive procedure for evaluation or transfusion within 6 weeks prior to presentation, or hemorrhagic stroke within the 6 weeks prior
• Neutropenia (WBC <2000 (mm)³), Anemia (HCT <30%, Thrombocytopenia (Thrombocytes <50,000 (mm)³). It is not necessary to confirm blood counts prior to start of study drug in the absence of clinical suspicion.
• Known or suspected aortic dissection.
• Prior history of pulmonary disease requiring chronic oxygen therapy.
• Pregnancy, lactating, and women of childbearing potential.
• Medical problem likely to preclude completion of the study.
• Use of investigational drugs or device within the 30 days prior to enrollment