A Clinical Trial to Assess the Elixir Medical LithiX Coronary Hertzian Contact Intravascular Lithotripsy Catheter

General Inclusion Criteria: 1. Subject is ≥ 18 years of age. 2. Subject or a legally authorized representative must provide written informed consent prior to any study related procedures. 3. Subject must agree not to participate in any other clinical study during the course of the study that would interfere with the endpoints of this study. 4. Subjects must have a single or double vessel coronary artery disease (CAD) and clinical evidence of ischemic heart disease, such as CAD, silent ischemia, stable / unstable angina, and NSTEMI if biomarkers are stable or falling at time of inclusion. Angiographic Inclusion Criteria: 1. Subject must have de novo lesion(s) in native coronary arteries suitable for percutaneous coronary intervention. 2. Up to 2 de novo coronary artery lesions in separate epicardial vessels, which are moderately to severely calcified, meeting all of the following criteria visually assessed by angiography: * ≥70% diameter stenosis by visual estimation * reference vessel diameters of 2.25 mm - 3.5 mm * lesion length of ≤ 34 mm * TIMI flow ≥ 1 at baseline 3. Any non-target lesion must be located in different coronary artery from a target lesion. Treatment of non-target lesion, if any, must be completed prior to treatment of target lesion and must be deemed a clinical angiographic success as visually assessed by the physician. General Exclusion Criteria: 1. Subject with a known hypersensitivity or contraindication to aspirin, heparin, bivalirudin, anti-platelet medications, or sensitivity to contrast media which cannot be adequately pre-medicated. 2. Subject with known diagnosis of STEMI at index presentation or within 7 days of study screening. 3. Patient refusing or not a candidate for emergency coronary artery bypass grafting (CABG) surgery. 4. Subject with known pregnancy or is nursing. Women of child-bearing potential should have a documented negative pregnancy test within 7 days before index procedure. 5. Planned use of atherectomy, laser, lithoplasty, thrombectomy, scoring or cutting balloon, or any investigational device other than LithiX in the target lesion during the index procedure. 6. Patients on renal dialysis or with known eGFR \< 30 ml/min. 7. NYHA class III or IV heart failure. 8. Patient has active systemic infection. 9. Cerebrovascular accident (CVA) or transient ischemic attach (TIA) within the past 6 months. 10. Active peptic ulcer or active gastrointestinal (GI) bleeding within the past 6 months. 11. Subject has a known left ventricular ejection fraction (LVEF) \<30% (LVEF may be obtained at the time of the index procedure if the value is unknown, if necessary). 12. Subject is a member of a vulnerable population as defined GCP E6, including individuals with mental disability, persons in nursing homes, children, impoverished persons, persons in emergency situations, homeless persons, nomads, refugees, and those incapable of giving informed consent. Vulnerable populations also may include members of a group with a hierarchical structure such as university students, subordinate hospital and laboratory personnel, employees of the Sponsor, members of the armed forces, and persons kept in detention. Angiographic Exclusion Criteria: 1. More than two target lesions or more than 1 target and 1 non-target lesion requiring treatment. 2. Extreme angulation (90º or greater) proximal to or within the target lesion. 3. Previous percutaneous intervention of lesions in a target vessel (including side branches) conducted within 6 months before the study procedure, or any prior lesion treated within 10 mm (proximal or distal) from the current target lesion. 4. Previous percutaneous intervention of lesions in a non-target vessel (including side branches) conducted within 30 days before the study procedure. 5. Angiographic evidence of a target lesion dissection prior to LithiX Hertzian Contact Lithotripsy. 6. Visible thrombus (by angiography) at target lesion site. 7. Unprotected left main coronary artery disease (Greater than 50% diameter stenosis). 8. Target lesion is located in a native vessel distal to anastomosis with a saphenous vein graft or LIMA/RIMA bypass. 9. Evidence of aneurysm in target vessel. 10. Coronary artery spasm of the target vessel in the absence of a significant stenosis. 11. Target lesion involves a bifurcation requiring treatment with more than one stent or pre-dilatation of a side branch \>2.0 mm in diameter