A Cohort Study of PCI Strategies for Severely Calcified Lesions of Complex Coronary Arteries in the Elderly

Inclusion Criteria: 1. Age ≥ 60 years; 2. Meet the indications for coronary intervention; 3. IVUS examination suggests severe calcified lesions (calcification angle \>270°) or OCT examination suggests severe calcified lesions (calcification angle \>180° and/or length \>5mm and/or thickness \>0.5mm); 4. The diameter of the target lesion vessel is greater than 2.75mm; 5. The total length of the lesion is more than 60mm and/or the number of lesions to be treated is ≥3 and/or the number of vessels to be treated is ≥2. Exclusion Criteria: 1. inability to provide written informed consent; 2. inability to administer antiplatelet agents and anticoagulant therapy; 3. the subject is participating in other unfinished clinical trials; 4. life expectancy \<1 year; 5. non-in situ vascular lesions; 6. patients with haemodynamic instability; 7. Previous stroke within 6 months. 8. left main stem lesions.