Detection of vein graft disease using high-resolution magnetic resonance angiography

Background-The application of previous magnetic resonance (MR) angiography techniques has enabled noninvasive differentiation between patent and occluded coronary artery bypass grafts. However, the detection of graft stenosis remains difficult. The purpose of our study was to determine the accuracy of high-resolution navigator-gated 3-dimensional (3-D) MR angiography in detecting vein graft disease. Methods and Results-MR angiography was performed in addition to coronary angiography with quantitative coronary analysis in 56 vein grafts from 38 patients (mean age 66.6+/-9.3 years), who presented with recurrent chest pain after bypass surgery. Eighteen grafts showed a luminal stenosis greater than or equal to50%, 11 grafts a stenosis greater than or equal to70% and 6 grafts were occluded. All MR angiograms were evaluated independently by 2 blinded observers, who scored the presence of graft occlusion and graft stenosis greater than or equal to50% and greater than or equal to70% with a confidence level of 1 to 10. MR image quality was judged as insufficient in 6 grafts and these were excluded. Receiver-operator characteristic analysis revealed an area under the curve of 0.89 and 0.89 for identifying graft occlusion, 0.81 and 0.87 for stenosis, greater than or equal to50%, and 0.82 and 0.79 for stenosis greater than or equal to70% for the 2 observers, respectively. Interobserver agreement in assessing graft occlusion and stenosis greater than or equal to50% and greater than or equal to70% was 94% (kappa=0.74, r=0.81), 72% (kappa=0.40, r=0.66), and 82% (kappa=0.53, r=0.72), respectively, Conclusions-High-resolution navigator-gated 3-D MR angiography allows not only good differentiation between patent and occluded vein grafts but also the assessment of vein graft disease with a fair diagnostic accuracy. This approach offers perspective as a noninvasive diagnostic tool for patients who present with recurrent chest pain after vein graft surgery.