Assessment of arterial grafts five years after coronary artery bypass grafting by multidetector computed tomography

Abstract

The arterial grafts are widely used in coronary artery bypass grafting for being durability. In patients with multivessel disease greater than 50%, using three to four grafts are required, and sometimes arterial and venous grafts are using them. However, clinical outcome, there is a greater incidence of cardiovascular events in the territory venous graft compared the bed of the graft artery. However, anatomical and functional behavior of arterial grafts has been little studied, especially in those patients with exclusive use of arterial grafts and asymptomatic or with events subclinical. With the advent of multi-detector computed tomography is possible to analyze the coronary arteries and arterial grafts with acceptable results for the assessment of patency, degree of stenosis and presence of atherosclerotic plaques. Objectives: To determine the rate of patency of arterial grafts and quantify potential injuries and atherosclerotic plaques in patients with coronary artery bypass using exclusively arterial grafts with at least five years by multidetector computed tomography. Methods: 50 patients will participate in the selected database Prof Dr Luiz Boro Puig Coronary Surgery Unit of InCor-FMUSP only in coronary artery bypass grafting with five years of the procedure. Individuals will be excluded: renal insufficiency (defined as creatinine clearance less 70mg/dl), liver failure, cancer, allergy to iodinated contrast, atrial fibrillation with high ventricular response and acute coronary syndrome. Selected patients will undergo a clinical and consulting the appointed day will be forwarded to the Department of Resonance and Computed Tomography of the Incor-HCFMUSP for examination during coronary angiography. The exams will be analyzed in a workstation Vitrea experienced observer in CT to ensure data reproducibility. Variables analyzed: 1) the multi-detector computed tomography: the presence of grafts and quantification of any injuries, the diameter of the grafts at three points (proximal, medial and distal), 2) clinical consultation: cardiovascular risk factors, medications in use, cardiovascular events (myocardial infarction, unstable angina and stable) after revascularization. Statistical analysis: The variables are initially analyzed descriptively. For qualitative variables are calculated as absolute and relative. For quantitative variables were observed minimum and maximum values and calculated values of mean, standard deviation and median. All statistical evaluation will be supervised by a statistician. (AU)