 Cardiac catheterization and percutaneous coronary intervention PCI. Patients will be admitted to the catheterization laboratory according to their clinical presentation, taking into account the current ESCAHA clinical guidelines. The cardiac catheterization procedure will be performed using standard percutaneous techniques via the radial or femoral artery. Coronary lesions will be evaluated by the operator in terms of stenosis by visual estimation or other using objective measurements, such as quantitative coronary analysis QCA. Coronary intervention, including balloon angioplasty and stent implantation will be implemented as needed and according to the severity of coronary stenosis i.e. 70 diameter stenosis. Adjunctive coronary imaging OCT or intravascular ultrasound will be performed according to operators discretion and regardless of the study protocol. All patients will be treated during the procedure with anticoagulation mostly unfractionated heparin using careful monitoring of activated clotting time between 250-300 seconds. After the angioplasty procedure, all patients will be treated with dual anti-platelet therapy combining aspirin and P2Y12 inhibitor clopidogrel, prasugrel or ticagrelor, according to the clinical indication for 6-12 months, unless there will be contra-indication, such as treatment with oral anti-coagulants. 