Nesiritide Therapy to Preserve Function of the Left Ventricle After Myocardial Infarction (BelieveII)

• EF and diastolic function determined by MUGA/ECHO at 30 days [ Time Frame: 30 days ] [ Designated as safety issue: No ]
• 30 day combined total mortality and hospitalization for CHF [ Time Frame: 30 days ] [ Designated as safety issue: No ]
• Circulating ANP, BNP, ET and Aldosterone [ Time Frame: 30 days ] [ Designated as safety issue: No ]
• Infarct size and LV mass as determined by cardiac MRI [ Time Frame: 30 days ] [ Designated as safety issue: No ]

• EF and diastolic function determined by MUGA/ECHO at 30 days
• 30 day combined total mortality and hospitalization for CHF
• Circulating ANP, BNP, ET and Aldosterone
• Infarct size and LV mass as determined by cardiac MRI

The purpose of this study is to determine the efficacy of intravenous human beta natriuretic peptide (BNP, Nesiritide) as compared to placebo to prevent adverse post acute myocardial infarction left ventricular remodeling.

Post acute myocardial infarction (AMI) left ventricular (LV) remodeling begins within hours of the acute event with permanent consequences. Previous studies have demonstrated that LV remodeling is one of the major determinants of long-term survival post AMI. Recent studies have reported that the cardiac natriuretic peptides, ANP and BNP have direct anti-fibrotic and anti-proliferative effects on the myocardium. More importantly, it has been reported that in the acute phase of AMI, the secretion of the cardiac natriuretic peptides may be insufficient relative to the chronic phase. Therefore, augmentation of the cardiac natriuretic peptide system, such as by exogenous administration of exogenous peptide may prevent post AMI LV remodeling because of the cardioprotective effects. The objective of this study is to to determine the efficacy of IV human BNP (Nesiritide) as compared to placebo to prevent adverse post AMI LV remodeling. This is a randomized double blinded placebo controlled study to determine efficacy of 72 hours of IV BNP at 0.006µg/Kg/min as compared to placebo in patients with anterior ST-elevation myocardial infarction and successful revascularization. The study population will include 60 patients admitted to the CCU with a first anterior AMI and successful reperfusion therapy (TIMI grade 3 flow) within 24 hours of onset of chest pain documented by coronary angiography.

• Drug: Nesiritide versus Placebo
  Infusion of 72 hours of IV nesiritide (Natrecor) at 0.006 mcg/kg/min as compared to placebo
  Other Name: Nesiritide (Natrecor, BNP)
• Drug: Nesiritide v. placebo
  Infusion of 72 hours of IV nesiritide (Natrecor) at 0.006 mcg/kg/min as compared to placebo
  Other Name: Natrecor(BNP), Nesiritide

• Placebo Comparator: Control
  Infusion of Nesiritide versus Placebo
  Intervention: Drug: Nesiritide versus Placebo
• Active Comparator: Nesiritide
  Infusion of Nesiritide v. placebo
  Intervention: Drug: Nesiritide v. placebo

Inclusion criteria:

• Patients with acute ST elevation myocardial infarction with > or = 2 mm ST elevation in one or any combination of anterior leads, with successful revascularization (TIMI grade 3 flow) of the lesion within 24 hours of symptoms and consented within 24 hours of procedure.

Exclusion criteria:

• Cardiogenic shock or hypotension, Systolic BP< 90 mmHg or overt CHF
• Previous history of MI
• Previous ECG suggesting previous MI
• Known EF < 30%
• Atrial fibrillation
• Previously known significant valvular disease (Grade III, IV), cardiomyopathy and congenital heart disease.
• Hemoglobin <10mg/dl.
• Pregnant women/nursing mothers
• Participants still menstruating and have not been surgically sterilized must have a negative pregnancy test prior to participating in this study.
• Unable to undergo cardiac MRI. Contraindications to MRI include pacemaker or defibrillator, pregnant women, atrial fibrillation or other arrhythmia, cerebral aneurysm clips or severe claustrophobia.