 Heart transplanted patients HTx often develop coronary artery disease CAD which is a major cause of graft failure and death in this group of patients. Therefore, heart transplanted patients have their coronary arteries examined annually. At present this is being done with coronary angiography. Recent development of the computed tomography CT technology has made it possible to examine the coronary arteries with CT angiography CTA, which is a non-invasive method. The goal of the study is to validate CTA against coronary angiography. 