• Subject is ≥18 years of age;

• Subjects with native coronary artery disease (including stable or unstable angina and silent ischemia) suitable for Percutaneous Coronary Intervention (PCI);

• For patients with unstable ischemic heart disease, a local site-based biomarker (preferably troponin or hs-troponin) must be less than or equal to the upper limit of lab normal (ULN) within 12 hours prior to the study procedure;

• For patients with stable ischemic heart disease, CK-MB will be drawn at the time of the study procedure from the side port of the sheath; results need not be analyzed prior to enrollment, but must be less than or equal to the upper limit of lab normal (ULN);

• Single de novo target lesion stenosis of protected LMCA, or LAD, RCA, or LCX (or of their branches) with:

‣ Stenosis of ≥70% and \<l00%; or

⁃ Stenosis ≥50% and \<70% (visually assessed) with evidence of ischemia via positive stress test, or fractional flow reserve value ≤0.80, or iFR \<0.90, or IVUS or OCT minimum lumen area ≤4.0 mm2;

• Evidence of calcification at the target lesion site by

‣ angiography, with fluoroscopic radiopacities noted without cardiac motion prior to contrast injection involving both sides of the arterial wall in at least one location and total length of calcium of at least 15 mm and extending partially into the target lesion, or

⁃ Intravascular Ultrasound (IVUS) or Optical Coherence Tomography (OCT), with presence of ≥270 degrees of calcium on at least 1 cross section;

• Ability to pass a 0.014 guidewire across the lesion.