Coronary artery disease is caused by narrowing of the artery lumen. Treatment with Percutaneous Coronary Intervention (PCI) may be needed. This is a minimally invasive procedure used to treat narrowed or blocked coronary arteries. Sometimes a stent is placed to keep the artery open. If the lesions in the coronary artery are calcified, this may cause difficulties for successful stent placement. The calcified plaques can be fractured via intravascular lithotripsy (IVL) with devices like ShockWave IVL and ShockFast IVL. The aim of this study is to compare the this relatively new ShockFast IVl with the more widely used ShockWave IVL.

Coronary calcified lesions have evolved as one of the most challenging indications for coronary percutaneous interventions (PCI). Different dedicated devices have been recently introduced into the market to improve procedural success in this challenging PCI population. Shockwave Intravascular Lithotripsy, (Shockwave IVL), Shockwave Medical, SC, CA, USA, was the first intracoronary device that used sonic pressure to fracture intracoronary calcium. The device safety and efficacy has been proved in a series of clinical trials. ShockFast intravascular lithotripsy (ShockFast IVL), Shunmei medical, Shenzhen, China, is a new dedicated device to treat intracoronary calcium that makes use of sonic pressure waves to fracture calcified plaques. ShockFast IVL has recently obtained CE mark approval for this indication.

The aim of this study is to compare this new lithotripsy device (ShockFast IVL) with the existing and widely used lithotripsy device that uses the same principle of action, the Shockwave IVL, Shockwave Medical, SC, CA, USA.

Inclusion Criteria:

1. Patients aged ≥18 years undergoing PCI for stable or unstable angina or staged procedure after successful treatment of a myocardial infarction where heart enzymes are decreasing

   Angiographic criteria:

2. Native de novo coronary lesions

3. Vessel diameter between 2.5mm - 4.0mm

4. Lesion Length: ≤40mm

5. Severe Calcification:

   1. Calcification visible on the upper and the lower sides of the vessel wall in at least two angiographic projections that differ ≥ 60° from each other
   2. Presence of severe calcified protruding noduli

6. No flow disturbances at baseline (Thrombolysis in Myocardial Infarction [TIMI] 3 flow at baseline)

7. Target lesion with diameter stenosis ≥70% by visual, or ≥50% with evidence of clinical ischemia

   OCT Criteria:

8. Total calcium arc > 180° or

9. Presence of a protruding calcified noduli

Exclusion Criteria:

1. Ejection fraction less than 25%
2. Lesion located in Left Main (LM) coronary artery
3. Calcifications located mostly > 0.5 mm from the vessel lumen.
4. Severe renal Impairment; Serum Creatinine > 220 μmol or currently undergoing hemodialysis
5. Severe lesion tortuosity where OCT is judged impossible to cross.
6. Inability to tolerate dual antiplatelet therapy for 6 months or longer
7. Inability to obtain inform consent or deemed poorly compliant by the investigator
8. Presence of permanent pacemaker
9. Angiographic evidence of thrombus in the target vessel
10. Target lesion located at or involving within 5mm of the coronary ostium of the Left Anterior Descending artery (LAD), Left Circumflex artery (LCX)
11. Target lesion is a chronic total occlusion (CTO)
12. Presence of aneurysm within 10mm proximal or distal to the target lesion