Coronary Angiography in the Diagnosis of Graft Failure

Despite its known limitations [1–3] coronary angiography has remained the standard technique to demonstrate alterations of coronary artery bypass grafts, especially so-called graft disease. This concerns above all those graft changes which lead to ischemic events such as stable and unstable angina pectoris or acute myocardial infarction. These alterations consist predominantly in localized, high-grade luminal narrowings (diameter stenoses ≥70%) of the graft body or the proximal or distal anastomoses or in occlusions of grafts due mainly to progressing atherosclerotic plaque formation with or without thrombotic occlusion. Graft angiograms are therefore always indicated when typical ischemic symptoms arise, or prophylactically when grafts approach the age at which the risk of vein graft disease increases significantly (5 and more years). This applies especially to patients with combined risk factors [4] and increased progression of graft atherosclerosis and plaque formation, as it is established that plaque rupture followed by thrombotic occlusion and myocardial infarction involves not only high-grade, symptomatic but also low-grade (<50%), clinically asymptomatic plaques not detectable by non-invasive means [2, 5, 6].