Intravascular Lithotripsy for Acute Stent Under-expansion in Calcified Coronary Lesions

Inclusion Criteria: * Radiography inclusion criteria 1. the angiography identified a severely calcified lesion with acute stent under-expansion, i.e., residual stenosis \>20% after stenting and 16-atm dilatation with a post-dilatation balloon; 2. target lesion stenosis must be ≥70% or ≥50% with clear evidence of myocardial ischaemia (visual assessment); 3. target lesion vessel diameter is between 2.75mm and 4.0mm, target lesion length must be ≤30 mm (visual assessment); General inclusion criteria 1. subjects at the age between ≥18 and ≤80 years old; 2. patients with symptoms or evidence of myocardial ischaemia; 3. subjects are willing to participate in the study, sign informed consent form, and accept clinical and angiography follow-up after PCI. Exclusion Criteria: * Radiography exclusion criteria 1. in-stent lesions; 2. For the left main disease and bifurcation lesion (branch vessel diameter shall be ≥ 2.5mm); 3. Target lesions were total occlusive lesions (acute or chronic), long lesions (\>30 mm), lesion vessel reference diameters \>4.0 mm, and lesion angiomatous dilatation; General inclusion criteria 1. Patients with severe congestive heart failure (NYHA Level IV severe heart failure) or severe valvular heart disease; or left ventricular ejection fraction of less than 35%; 2. Patients with stroke, peptic ulcer or gastrointestinal bleeding within the past 6 months; or patients with bleeding tendency or coagulation disorders; 3. Patients with severe liver failure (ALT and AST are larger than 3 times of the upper limit of normal value), who are judged to be not applicable to angiography by investigators; 4. Patients with severe renal failure(eGFR\<30ml/minute) or such medical history, failure to comply with angiography conditions; 5. Subjects who are intolerance or allergic to heparin, contrast agent, Biolimus, polyethylene oxide and polylactic acid - glycolic acid polymer; 6. Patients who plans to accept selective operation within 1 year; 7. Patients who are participating in the clinical trial of other drug or device without reaching the time limit of primary endpoint; 8. Subjects who are considered to be not applicable to be enrolled by investigators due to other reasons.