Study of Unprotected Left Main Stenting Versus Bypass Surgery (LE MANS Study)

Inclusion Criteria: * The patients' age 18 to 80 * Significant LM stenosis (\>50%) * The target vessel reference diameter 2.5mm. * Concomitant multivessel disease suitable for PCI is allowed. * The patient is an acceptable candidate for coronary artery bypass surgery. * The patient agreement for 6 month follow-up cardiac catheterization, which will include left ventricular angiogram. * The patient written informed consent. Exclusion Criteria: * An allergy or contraindication to aspirin, ticlopidine or Clopidogrel. * Presence of diffuse, significant (\>++) calcifications in LM * Left ventricular ejection fraction \< 35% * History of bleeding diathesis or coagulopathy. * Any previous PCI or CABG surgery * Acute MI within 48 hours, cardiogenic shock. * Bail-out stenting of dissected LM during complicated PCI. * The patient suffered a stroke or transient ischemic neurological attack (TIA) within 3 months. * Chronic renal insufficiency. * Positive pregnancy test. * Any disease that may shorten the life expectancy of the patient. * The patient is currently participating in another research study.