Prospective, multi-center, single arm study designed to evaluate the safety and performance of the Shockwave Coronary Rx Lithoplasty® System to treat calcified lesions in the coronary arteries for the purpose of enhancing the placement of stents and reducing the ultimate residual stenosis. Patients will be followed through discharge and at 30 and 180 days.

Prospective, multi-center, single arm study designed to evaluate the safety and performance of the Shockwave Coronary Rx Lithoplasty® System to treat calcified lesions in the coronary arteries for the purpose of enhancing the placement of stents and reducing the ultimate residual stenosis. Patients will be enrolled and consented in the study based on history and in some instances an angiogram obtained prior to the study. The study is designed to demonstrate that the Shockwave device can safely and effectively deliver localized shockwave energy for balloon dilatation of calcified, stenotic, coronary arteries. Subjects will be prepared for PCI per the institution's standard protocol. Medications will be administered per the treatment protocol. Femoral access will be obtained using a 6F access sheath, and guiding catheter placed at the ostia of the right or left coronary artery. Baseline angiography of the culprit lesion will be performed prior to placement of a 0.014" guide wire. Baseline and either IVUS or OCT will be performed to determine the Maximum Lumen Area (MLA), percent stenosis, and volumetric lesion assessment. Baseline angiography will be performed to determine lesion length, % stenosis and reference vessel diameter. The investigational device will be prepped per the IFU and positioned at the target lesion. The distal end of the balloon catheter will be connected to the patient cable. The balloon catheter will be inflated to 4 atm and the investigator will deliver 10 pulses for 20 seconds. The balloon will then be inflated to reference vessel diameter and then deflated to reestablish flow and complete one treatment cycle. The treatment cycle will then be repeated. Angiography and either IVUS or OCT will be repeated for the treated lesion.. A coronary stent will be deployed at the site of treatment. Angiography and either IVUS or OCT will be performed following stent placement. Patients will be followed through discharge and at 30 and 180 days. A subset of up to five (5) subjects will receive an angiographic assessment at the 180 day follow up visit, per the Sponsor's discretion.

Inclusion Criteria:

1. Patient is ≥ 18 years of age
2. Troponin must be less than or equal to the upper limit of lab normal value within 12 hours prior to the procedure
3. The target vessel must have a TIMI flow 3 at baseline
4. Patients with significant (≥ 50% diameter stenosis) native coronary artery disease including stable or unstable angina and silent ischemia, suitable for PCI
5. Ability to tolerate dual antiplatelet agent (i.e. aspirin, clopidogrel, prasugrel, or ticagrelor for 1 year and single antiplatelet therapy for life
6. Single lesion stenosis of protected LMCA, or LAD, RCA or LCX artery ≥50% in a reference vessel of 2.5 mm - 4.0 mm diameter and ≤ 32 mm length
7. Presence of calcification within the lesion on both sides of the vessel as assessed by angiography
8. Planned treatment of single lesions in one vessel
9. Ability to pass a 0.014" guide wire across the lesion
10. Patient, or authorized representative, signs a written Informed Consent form to participate in the study, prior to any study-mandated procedures
11. Patient is able and willing to comply with all assessments in the study

Exclusion Criteria:

1. Concomitant use of Atherectomy, Specialty balloon, or investigational coronary devices
2. Prior PCI procedure within the last 30 days of the index procedure
3. Patient has planned cardiovascular interventions within 30 days post index procedure
4. Second lesion with ≥50% stenosis in the same target vessel
5. Left ventricular ejection fraction < 40%
6. Patient refusing or not a candidate for emergency coronary artery bypass grafting (CABG) surgery
7. Uncontrolled severe hypertension (systolic BP >180 mm Hg or diastolic BP >110 mm Hg)
8. Severe renal failure with serum creatinine >2.5 mg/dL
9. Untreated pre-procedural hemoglobin <10 g/dL
10. Coagulopathy manifested by platelet count <100,000 or International Normalized ratio (INR) >1.7 (INR is only required in patients who have taken warfarin within 2 weeks of enrollment)
11. Patients in cardiogenic shock
12. Acute myocardial infarction (MI) within the past one (1) month, and/or elevated Troponin-I or T (with concomitant elevation of CPK) at the time of enrollment.
13. History of a stroke or transient ischemic attack (TIA) within 3 months
14. NYHA class III or IV heart failure
15. Active peptic ulcer or upper gastrointestinal (GI) bleeding within 6 months
16. Patients with a life expectancy of less than 1 year
17. Target vessel < 2.4 mm in diameter
18. Target lesion > 32 mm in length
19. Chronic Total Occlusion (CTO)
20. Previous stent procedure within 5 mm of target lesion
21. Angiographic evidence of a target lesion severe dissection prior to Coronary Lithoplasty treatment
22. Unprotected Left Main diameter stenosis ≥ 50%
23. Visible thrombus (by angiography) at target lesion site
24. Target lesion is located in a native vessel distal to anastomosis with a saphenous vein graft or LIMA/RIMA bypass
25. Patient has active systemic infection
26. Patient has connective tissue disease (e.g., Marfan's syndrome)
27. Patient has a hypercoagulable disorder
28. Uncontrolled insulin dependent diabetes
29. Patient has allergy to imaging contrast media for which they cannot be pre-medicated
30. Evidence of aneurysm in target vessel
31. Patient is pregnant or nursing

through 30 days and 6 months