Xinyu Wang1,2,3,4, Benedict T Costello5, Stavroula Papapostolou5, Jessica O'Brien5, Andrew Taylor5, Shihua Zhao6. 1. Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital. 2. NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides. 3. Key Laboratory of Molecular Cardiovascular Science, Ministry of Education. 4. Beijing Key Laboratory of Cardiovascular Receptors Research. 5. Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Vic., Australia. 6. Department of MRI, Fuwai Hospital, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
Abstract
PURPOSE: The purpose of this study was to differentiate nonischemic dilated cardiomyopathy with incidental myocardial infarction (NICM with incidental MI) from ischemic cardiomyopathy (ICM) by integrating left ventricular (LV) geometric indices and ischemic late gadolinium enhancement (LGE), obtained from cardiac magnetic resonance (CMR) imaging. MATERIALS AND METHODS: All subjects were studied on a 1.5 Tesla magnetic resonance imaging scanner. All patients had an LV ejection fraction (LVEF) <50% with LV dilation. LV end-diastolic volume (LVEDV), LVEDV index (LVEDVi), LVEF, the number and distribution of ischemic LGE segments, and ratios of volumetric and functional indices to ischemic LGE segments were determined. Logistic regression was used to detect the independent predictor of ICM. Receiver operating characteristic analysis differentiated NICM with incidental MI from ICM. RESULTS: Of a total of 63 patients enrolled, 45 patients had ICM, and 18 patients had NICM with incidental MI. Both groups had similar LVEF. Compared with ICM, NICM with incidental MI had more LV dilation, whereas ICM had more ischemic LGE segments. A higher number of ischamic LGE segments remained an independent predictor of ICM (odds ratio: 18.2, 95% confidence interval: 1.64-201.34, P=0.018). The optimal cut-off value for detecting NICM with incidental MI is the ratio of LVEDVi to the number of ischemic LGE segments over 25 mL/m2/segment (sensitivity 100%, specificity 91%, P<0.0001). CONCLUSION: Patients with NICM with incidental MI can be reliably distinguished from ICM using the ratio of LVEDVi divided by the number of ischemic LGE segments. This technique may improve diagnosis and help aid management of patients with cardiomyopathy and coexistent coronary artery disease.
PURPOSE: The purpose of this study was to differentiate nonischemic dilated cardiomyopathy with incidental myocardial infarction (NICM with incidental MI) from ischemic cardiomyopathy (ICM) by integrating left ventricular (LV) geometric indices and ischemic late gadolinium enhancement (LGE), obtained from cardiac magnetic resonance (CMR) imaging. MATERIALS AND METHODS: All subjects were studied on a 1.5 Tesla magnetic resonance imaging scanner. All patients had an LV ejection fraction (LVEF) <50% with LV dilation. LV end-diastolic volume (LVEDV), LVEDV index (LVEDVi), LVEF, the number and distribution of ischemic LGE segments, and ratios of volumetric and functional indices to ischemic LGE segments were determined. Logistic regression was used to detect the independent predictor of ICM. Receiver operating characteristic analysis differentiated NICM with incidental MI from ICM. RESULTS: Of a total of 63 patients enrolled, 45 patients had ICM, and 18 patients had NICM with incidental MI. Both groups had similar LVEF. Compared with ICM, NICM with incidental MI had more LV dilation, whereas ICM had more ischemic LGE segments. A higher number of ischamic LGE segments remained an independent predictor of ICM (odds ratio: 18.2, 95% confidence interval: 1.64-201.34, P=0.018). The optimal cut-off value for detecting NICM with incidental MI is the ratio of LVEDVi to the number of ischemic LGE segments over 25 mL/m2/segment (sensitivity 100%, specificity 91%, P<0.0001). CONCLUSION:Patients with NICM with incidental MI can be reliably distinguished from ICM using the ratio of LVEDVi divided by the number of ischemic LGE segments. This technique may improve diagnosis and help aid management of patients with cardiomyopathy and coexistent coronary artery disease.