The goal of this observational, prospective, multicenter study is to explore local action of coronary calcium fragmentation exerted by endovascular lithotripsy by images acquired with OCT, in patients with coronary artery calcifications responsible for significant stenosis, candidate to PCI. The main question it aims to answer, is the ability of Shockwave System to reduce calcium density in the Region of Interest (ROI) of the vessel wall.

Coronary arteries with calcific lesions will undergo intravasculary lithotripsy (IVL) treatment; OCT acquisition will be performed before IVL treatment, after IVL treatment and after stent-implantation. All OCT frames will be uploaded on the image processing and analysis program ImageJ (US National Institutes of Health). ROI will be selected as part of image where calcium is located. Image analysis will be performed using frequency histogram of pixel density in the ROI pre- and post-IVL, as a measure of calcium density. Mean pixel density of the ROI before IVL will be compared with mean pixel density of the ROI after IVL, measuring delta pixel density.

Inclusion Criteria:

• Subjects with native coronary artery disease (including stable or unstable angina and silent ischemia) suitable for PCI
• Left ventricular ejection fraction (LVEF) ≥35% as measured prior to enrollment
• eGFR ≥45 ml/min (Cockroft-Gault, MDRD)
• Troponin must be less than or equal to the upper limit of lab normal value within 24 hours prior to the procedure or if troponin is elevated, concomitant CK must be normal
• Ability to tolerate dual antiplatelet therapy (i.e. aspirin and clopidogrel, prasugrel, or ticagrelor) for at least 6 months (for patient not on oral anticoagulation) and single antiplatelet therapy for life
• The target lesion must be a de novo coronary lesion that has not been previously treated with any interventional procedure
• Single de novo target lesion stenosis of LAD, RCA or LCX (or of their branches) with stenosis of ≥70% and <100% or stenosis ≥50% and <70% (visually assessed) with evidence of ischemia via positive stress test, or fractional flow reserve value ≤0.80, or iFR <0.89 or IVUS or OCT minimum lumen area ≤4.0 mm²
• Reference vessel must have 2.5 mm - 4.0 mm diameter and ≤ 30 mm length
• Evidence of calcification at the lesion site assessed by angiography, with fluoroscopic radio-opacities 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 by IVUS or OCT, with presence of ≥270 degrees of calcium on at least 1 cross section
• Planned treatment of single lesion for every target vessel
• Ability to pass a 0.014" guide wire across the lesion
• The target vessel must have a TIMI flow 3 at baseline

Exclusion Criteria:

• Left ventricular ejection fraction (LVEF) <35%
• Subject is pregnant or nursing
• eGFR <45 ml/min (Cockroft-Gault, MDRD) or chronic dialysis
• Untreated pre-procedural haemoglobin <9 g/dL or intention to refuse blood transfusions if one should become necessary
• Patient has a platelet count <100,000 cells/mm3 or >750,000 cells/mm3
• Patient has a known allergy to protocol required medications (clopidogrel, thienopyridines, aspirin, contrast media) that cannot be adequately premedicated
• Uncontrolled diabetes defined as a fasting hyperglycaemia >200 mg/dL or HbA1c greater than or equal to 10%
• Patient has had a cerebrovascular accident (CVA) or transient ischemic attack (TIA) within the past 6 months, or has any permanent neurologic defect that may cause non-compliance with the protocol
• Patient has an active peptic ulcer or active gastrointestinal (GI) bleeding
• Patient has a history of coagulopathy
• Subject is participating in another research study involving an investigational agent (pharmaceutical, biologic, or medical device) that has not reached the primary endpoint
• Subjects with a life expectancy of less than 1 year
• Subject refusing or not a candidate for emergency coronary artery bypass grafting (CABG) surgery
• Planned use of atherectomy, scoring or cutting balloon, or any investigational device other than lithotripsy
• Stent implantation in the target vessel within the last year or a stent within 10 mm of the target lesion
• Definite or possible thrombus (by angiography or intravascular imaging) in the target vessel
• Angiographic evidence of a dissection in the target vessel at baseline or after guidewire passage

All patients in the Catheterization Laboratory that undergo coronary angiography, are potentially selected.