Safety and accuracy of multidetector row computed tomography for early assessment of residual stenosis of the infarct-related artery and the number of diseased vessels after acute myocardial infarction Kuan-Rau Chiou, MD, a,c,d Ming-Ting Wu, MD, b,c Shih-Hung Hsiao, MD, a,c Guang-Yuan Mar, MD, a,c Huay-Ben Pan, MD, b,c Chien-Fang Yang, MD, b,c and Chun-Peng Liu, MD a,c Taiwan, Republic of China Background Recent studies reveal that contrast-enhanced multidetector row computed tomography (MDCT ) is a promising technique for noninvasive visualization of coronary artery stenoses. We investigated the safety and accuracy of MDCT for early assessment of the severity of residual stenosis of the infarct-related artery (IRA) and the number of diseased vessels in patients after acute myocardial infarction (AMI). Methods and Results Of 146 AMI cases admitted, 72 fit with criteria and underwent 16-slice MDCT (4 F 2 days after AMI) with h-blockers. There were no complications except 1 patient who had from complete atrioventricular block. Results were compared with conventional coronary angiography (CCA) within 3 days. In 55 (73.3%) of 72 patients, all arteries were assessable. In total, the number of assessable arteries was 253 (87.8%), and 35 (12.2%) vessels were nonassessable, mostly because of motion artifacts and extensive calcification. Overall, 84 of the 115 lesions (R50% lumen reduction) were correctly detected by MDCT (sensitivity 73.0%). The accuracy in classifying patients with nonsignificant, single-, or multiple-vessel diseases was 79.1%. The accuracy for residual lesions with N50% stenosis of IRA was 87.5%. There was a good correlation regarding the severity of residual stenosis of the IRA (0%, 1%-49%, 50%-89%, 90%-99%, or occlusion) between MDCT and CCA (Spearman correlation 0.94, P b .001). Lesions with 90% to 99% or occlusion of the IRA were accurately detected or ruled out in 31 of 36 cases (86.1%). Conclusions With appropriate protocol, MDCT is safe and accurate in assessing the severity of IRA and the number of diseased vessels during the first week after AMI. It has the potential to provide triage for early management of patients after AMI. ( Am Heart J 2005;149:701- 8.) Early assessment of the severity of residual stenosis of the IRA and the number of diseased vessels for patients with acute myocardial infarction (AMI ) has been shown to be important in guiding future patient management, whether or not the patient has undergone thrombolytic treatment. Practically, noninvasive assessment after AMI includes clinical predictors and stress modalities. How- ever, the accuracy of clinical predictors, such as chest symptoms, the degree of resolution of ST-segment deviation, and analysis of time-activity curves of cardiac biomarkers to identify patients who failed reperfusion is insufficient. 1,2 Even conventional noninvasive stress mo- dalities such as exercise testing, dipyridamole–sestamibi imaging, or dobutamine–stress echocardiography usually rely on indirect evidence for the presence of coronary stenosis. 3 The accuracy of these modalities for the detection of residual stenosis of the IRA and presence of multivessel disease early after AMI still has limitations. 4,5 Magnetic resonance imaging and electron-beam com- puted tomography 6,7 have been investigated for nonin- vasive coronary imaging. More recently, contrast- enhanced multidetector row computed tomography ( MDCT ) with retrospectively gated electrocardiogram ( ECG) reconstruction was introduced as a new modal- ity for this application. 8-10 MDCT using 16-slice com- puted tomography (CT ) scanners further improved spatial and temporal resolution, especially through decreased slice thickness and faster rotation time. Studies revealed that contrast-enhanced 16-slice MDCT is able to detect coronary artery stenoses with high From the a Division of Cardiology, Department of Internal Medicine, b Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung, c School of Medicine, and d Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China. Submitted May 19, 2004; accepted July 20, 2004. Reprint requests: Chun-Peng Liu, MD, Division of Cardiology, Kaohsiung Veterans General Hospital, 386 Dar-Chung First Road, Kaohsiung 813, Taiwan, Republic of China. E-mail: cpliu@isca.vghks.gov.tw 0002-8703/$ - see front matter n 2005, Elsevier Inc. All rights reserved. doi:10.1016/j.ahj.2004.07.030