Myocardial Contrast Echocardiography for the Assessment of the Infarct Related Artery & Risk Area in Patients w/ NSTEMI.

Patients presenting with NSTEMI who are scheduled to undergo elective cardiac catheterization and coronary angiography with primary PCI will be selected for participation in the study. The patients will undergo a clinically indicated resting non-contrast echocardiogram to assess LV function and regional wall motion. They will then undergo contrast echocardiography with bolus injection of Optison™ contrast to reassess LV ejection fraction, improve LV opacification and assess regional wall motion abnormalities. Finally, they will be given a continuous infusion of Optison™ and will have assessment of myocardial perfusion of each of the 17 myocardial segments using low mechanical index continuous imaging of the myocardium and blood pool. Two expert echocardiographers will be asked to review in a blinded fashion the non-contrast echocardiogram, interpret the ejection fraction, and assess regional wall motion abnormalities in each of the 17 myocardial segments. They will then be asked to predict the infarct-related artery (either LAD, LCx, or RCA). A proposed sample size of 100 patients presenting to Cedars-Sinai Medical Center with their first NSTEMI will be studied. Based on hospital volume, approximately 4-5 NSTEMI patients present to Cedars-Sinai on a weekly basis, of which at least 2 will be eligible per week. Based on this trend, we feel we can achieve the necessary sample size within 12 months. Inclusion criteria will be patients aged 31-90 presenting with World Health Organization diagnosis of non-ST segment elevation myocardial infarction, which encompass 2 out of the following 3 criteria: a clinical history of chest pain unrelieved by nitroglycerin, ECG evidence of cardiac ischemia (ST segment depression or T wave inversion), and enzymatic evidence of myocardial infarction (elevation of TnI or CKMB). Patients should be clinically eligible for coronary angiography.