Abstract 14046: Hibernating Myocardium in Chronic Ischemic Heart: Demonstration by 256-MSCT 4-D Color-coded Perfusion Imaging
We investigated the utility of 256-MSCT incorporating coronary angiogram, cine, and myocardial perfusion imaging in a single examination at rest to evaluate hibernating myocardium in chronic ischemic heart.
Methods: In 20 patients with prior myocardial infarction, CT coronary angiogram (CTCA) with retrospective ECG gate and myocardial perfusion scintigraphy (MPS) were performed. 4D color-coded perfusion images (4D-MPI) at 10 phases during a cardiac cycle using the same raw data as those used for CTCA were reconstructed. CT number [Hounsfield unit; HU] in the myocardium was used as an estimate of myocardial perfusion. The myocardium was shown using a color scale that depicted faint low attenuation area (LAA; 0 to 60 HU). First, combining of cine 4D-MPI and CTCA detected akinetic myocardial segments related to significantly stenosed coronary arteries. Next, we assessed the transmurality of myocardial perfusion in these segments using 4D-MPI, and compared the Results with those of stress/rest MPS. The criterion on stress/rest MPS was referenced as standard. A fixed perfusion defect at stress and rest was defined as non-viable; a perfusion defect at stress and the presence of redistribution at rest was defined as hibernating myocardium.
Results: Combing with cine 4D-MPI and CTCA detected 33 akinetic segments related significant stenosed artery in 9 of 20 patients. In the 33 segments, 4D-MPI showed 9 segments with transmural LAA (the extent of LAA in the wall thickness 75% and more) and 24 segments with subendocardial LAA (the extent of LAA in wall thickness less than 75%). Stress/rest MPS diagnosed all 9 segments with transmural LAA as non-viable, 22 of the 24 segments (92%) with subendocardial LAA as hibernating myocardium, and other 2 segments as non-viable.
Conclusions: 256-MSCT with 4D-MPI and CTCA demonstrates that subendocardial LAA with akinetic segments related stenosed coronary arteries characterizes hibernating myocardium in chronic ischemic heart.
- © 2010 by American Heart Association, Inc.