Abstract 16870: Myocardial Enhancement on 320 Detector-Row CT Acquired Immediately after PCI in Patients with Acute Myocardial Infarction: Comparison with Contrast Enhanced CMR in Acute and Chronic States
Background: Identification of irreversibly injured myocardium early after percutaneous coronary intervention (PCI) is important for optimizing management in patients with acute myocardial infarction (AMI). Myocardial CT acquired immediately after PCI is an emerging method that permits viability assessment without additional injection of iodine contrast medium in CT room. The purpose of this study was to determine the relation between CT late enhancement and contrast enhanced CMR findings in acute and chronic states.
Methods: Fifteen consecutive patients with AMI (59±12 years, 13men) underwent 320 slice MDCT immediately after PCI (peak CK 2295±1309). All patients achieved TIMI flow grade 3 after PCI. CMR studies were performed in acute phase (6.5±3.9 days) and chronic phase(7.3±1.4 months) in all patients. Rest perfusion MRI, late gadolinium enhancement (LGE) MRI and displacement encoded (DENSE) MRI were performed by using a 1.5T MR imager with 32-ch coil. CT-LE, CMR microvascular obstruction (MO) in acute state, CMR-LGE and myocardial strain in acute and chronic states were determined by using a 16-segments model. Transmural lesion was defined as the segment with transmural extent of >50%
Results: CT-LE was observed in 77 (32.1%) of 240 segments (transmural extent 1-25%;n=9, 26-50%;n=36, 51-75%;n=5, 76-100%;n=27). On CMR obtained in acute state, CMR-LGE and CMR MO was observed in 137 (57.1%) and 31 (12.9%) segments, respectively. CMR LGE was found in 129 (53.8%) segments in chronic state. The area under the receiver operating characteristics curve (AUC) of transmural extent of CT-LE for predicting CMR-MO was 0.824. These values were 0.813 for transmural CMR-LGE in acute phase and 0.754 for transmural CMR-LGE in chronic phase (p<0.001, respectively). In the segments with transmural CT-LE, myocardial radial strain determined by DENSE MRI was more severely impaired (p<0.001) in comparison with other segments.
Conclusion: CT-LE on MDCT acquired immediately after primary PCI was closely associated with MO and transmural LGE on CMR in acute state, and indicates poor functional recovery in chronic state. CT-LE can provide valuable information regarding regional myocardial damage and viability in AMI patients after PCI.
- © 2011 by American Heart Association, Inc.