Objectives: comparing the clinical outcomes of rotational atherectomy (RA) and conventional PCI methods on heavily calcified lesions in patients with high calcium scores detected. Methods: This was a clinical trial conducted on 30 patients aged above 18 years, their angiography proved coronary artery disease, having anginal symptoms and/or reproducible ischemia in the target area by ECG, functional stress testing, or fractional flow reserve, their calcium score more than 1000 on MS-CT coronary angiography. Patients were randomly assigned to 2 groups: Group A rotational atherectomy followed by DES implantation and Group B PCI through balloon predilatation using noncompliant balloons to facilitate device crossing followed by DES implantation. Angiographic assessment imm