ECLIPSE-EVALUATION OF TREATMENT STRATEGIES FOR SEVERE CALCIFIC CORONARY ARTERIES: ORBITAL ATHERECTOMY VS. CONVENTIONAL ANGIOPLASTY TECHNIQUE PRIOR TO IMPLANTATION OF DRUG-ELUTING STENTS: (ECLIPSE). The purpose of this trial is to evaluate orbital atherectomy vessel preparation compared to standard angioplasty prior to placing a stent for the treatment of Coronary Artery Disease (CAD). The Diamondback 360® Coronary Orbital Atherectomy System (OAS) uses a diamond-coated crown that spins back and forth inside your blocked artery (blood vessel) to sand and reduce the calcium. Atherectomy is the medical term describing the removal of plaque from the arteries. The use of the OAS is called orbital atherectomy (OA). Standard angioplasty will allow vessel preparation with any device, except for atherectomy, that has been approved or cleared by the Food and Drug Administration (FDA) for treating CAD. None of the devices used in this trial are experimental. This trial is designed to collect information about how each treatment affects the outcomes of the patients who choose to participate.