TI-201 Myocardial SPECT is an Effective Imaging Modality for Differentiating Ischemic from Non-ischemic Dilated Cardiomyopathy in Patients with Left Ventricular Dysfunction

Ching-Pei Chen ； Ching-Hui Huang ； Chiang-Hsuan Lee ； Jhi-Joung Wang ； Ming-Che Chang ； Chao-Wei Yang ； Guang-Uei Hung ； Wen-Sheng Huang

《The Changhua Journal of Medicine》 12卷1期 (2014/03) Pp. 17-23

並列摘要

Background: The presence of perfusion defects on Thallium-201 (Tl-201) myocardial perfusion imaging (MPI) makes it difficult to differentiate non-ischemic dilated cardiomyopathy (DCM) from ischemic cardiomyopathy (ICM) in patients with left ventricular dysfunction. The purpose of this study was to investigate Tl-201 MPIrelated factors that can discriminate ICM from DCM. Materials and Methods: We retrospectively reviewed the medical records of 21 patients with echocardiographic evidence of severe left ventricular dysfunction (ejection fraction ＜40%) who underwent TI-201 single-photon emission computed tomography (SPECT) and coronary angiography procedures within a one-month period. Of them, 12 patients had ICM (defined as stenosis＞70% in at least one coronary artery on coronary angiography) and 9 patients had DCM (defined as no evidence of stenosis＞70% in any coronary artery). SPECT was interpreted using a 17-segment model and a 0 to 4 scoring system. Perfusion defects with a score of 3 or more in a single segment were considered ＂severe＂ and those that presented in 3 or more consecutive segments were considered ＂large＂. Summed stress score (SSS) and summed rest score (SRS) were also generated for semiquantitative analysis of perfusion defects. Results: There was no significant difference in frequency of perfusion defects between patients with ICM and patients with DCM (100% vs. 78%, p＞0.05). Nonetheless, the mean SSS was significantly higher in the ICM group (27.9±13.3) than in the DCM group (8.7±7.9) (p＜0.001). Although there was no significant difference in frequency of large defects between patients with ICM (n=12, 100%) and those with DCM (n=6, 67%) (p＞0.05), there were significant differences in frequency between patients with severe defects in the ICM group (n=10, 83%) and those in the DCM group (n=2, 22%; p=0.005) and in the frequency of large and severe defects between patients with ICM (n=10, 83%) and those with DCM (n=1, 11%; p＜0.001). Receiver operating characteristic (ROC) curve analysis revealed that the optimal diagnostic cut-off values for SSS and SRS were 19 and 8, respectively. In addition, both scores had a sensitivity of 83% and a specificity of 89%. In contrast, visual interpretation of the presence of perfusion defects had a sensitivity of 100% and a specificity of 22% while the sensitivity and specificity associated with the presence of large or severe defects were 83% and 89%, respectively. Conclusion: Perfusion defects in patients with ICM are more severe than those in patients with DCM. We found that Tl-201 SPECT was a helpful modality for discriminating ICM from DCM, regardless of whether semiquantitative analyses of SSS and SRS or visual determination of defects was used.

並列關鍵字

Ischemic Cardiomyopathy ； Dilated Cardiomyopathy ； Thallium-201 ； Myocardial perfusion imaging