Coronary Orbital Atherectomy System Study

Inclusion Criteria: * Subjects must be 18 or older. * Subjects must have a clinical indication for coronary intervention. * CK and CK-MB must be less than or equal to the upper limit of lab normal value within 8 hours prior to the procedure. * The target lesion must be a de novo coronary lesion that has not been previously treated with any interventional procedure. * The target vessel must be a native coronary artery. * The target vessel reference diameter must be \>= 2.5mm and \<= 4.0 mm. * The lesion length must not exceed 40 mm. * The target vessel must have a TIMI flow three (3) at baseline. * The target lesion must have fluoroscopic, IVUS or OCT evidence of severe calcium deposit at the lesion site. * The lesion must be crossable with the study guide wire. Exclusion Criteria: * Inability to understand the study requirements or has a history of non-compliance with medical advice. * Unwilling to sign the COAST ICF. * History of any cognitive or mental health status that would interfere with study participation. * Currently enrolled in any other pre-approval investigational study. * Female subjects who are pregnant or planning to become pregnant within the study period. * Known hypersensitivity or contraindication to aspirin, heparin, ticlopidine or clopidogrel without adequate alternative medications. * Known sensitivity to contrast media, which cannot be adequately pre-medicated. * Diagnosed with chronic renal failure unless under hemodialysis, or has a serum creatinine level \> 2.5 mg/dl. * Experienced acute MI, STEMI or non-STEMI: CK-MB greater than the upper limit of lab normal value, within 30 days prior to index procedure. * History of major cardiac intervention within 30 days. * Evidence of heart failure * History of a stroke or TIA within six (6) months. * Active peptic ulcer or upper GI bleeding within six (6) months. * History of bleeding diathesis or coagulopathy or intention to refuse blood transfusion, if one should become necessary. * Concurrent medical condition with a life expectancy of \< 12 months. * History of immune deficiency. * Uncontrolled insulin dependent diabetes. * Evidence of active infections on the day of the index procedure. * Subject has planned cardiovascular intervention within 60 days post index procedure. * Subject is not an acceptable candidate for emergent CABG surgery. * Subject with known allergy to atherectomy lubricant components such as soybean oil, egg yolk phospholipids, glycerin and sodium hydroxide. * Subject with angiographically confirmed evidence of more than one (1) lesion requiring intervention, unless the treatment of the lesions is staged. * Target lesion is located in a native vessel distal to anastomosis with a saphenous vein graft or LIMA/RIMA bypass. * Target vessel has other lesions with greater than 50% diameter stenosis based on visual estimate or on-line QCA. * Target vessel has angiographically visible or suspected thrombus. * Target vessel has a stent from previous PCI. * Target vessel appears to be or is excessively tortuous at baseline. * Target lesion is an ostial location (within 5 mm of ostium) or an unprotected left main lesion. * Target lesion is a bifurcation. * Target lesion has a ≥ 1.5 mm side branch. * Angiographic evidence of a dissection prior to initiation of OAD.