The goal of this clinical trial was to compare the effectiveness of drug balloons versus drug-coated stents in calcified lesions in elderly coronary artery disease. The main question it aims to answer is whether the application of DCB is non-inferior to DES for in situ large vessel calcified lesions in the elderly coronary arteries.

And to develop a method to precisely identify the nature and extent of calcified lesions and to rationalize the choice of pretreatment.

Inclusion Criteria:

• 1. older than 60 years of age.
• 2. meeting the indications for coronary intervention.
• 3. IVUS examination suggests severe calcified lesions (calcification angle > 270° at the target lesion) ;
• 4. Target lesion vessel diameter > 2.75 mm

Exclusion Criteria:

• 1. inability to provide written informed consent.
• 2. unable to administer antiplatelet agents and anticoagulant therapy; have allergies to heparin, contrast agents, etc.
• 3. the subject is participating in another uncompleted clinical trial
• 4. life expectancy <1 year.
• 5. non-in situ vascular lesions.
• 6. cardiogenic shock.
• 7. Patients with hemodynamic instability