Assessing stent restenosis using 64-multidetector computed tomography coronary angiography / 대한내과학회지

BACKGROUND/AIMS: Multidetector computed tomography (MDCT) is considered to be a noninvasive, alternative method for evaluating stent restenosis. However, the diagnostic accuracy of 16-channel MDCT for stent stenosis is reported to have severe limitations because of high-attenuation stent-related artifacts. 64-channel MDCT, which recently became available in clinical practice, has better spatial and temporal resolution than 16-channel MDCT. The diagnostic accuracy of 64-channel MDCT for stent restenosis (in-segment and in-stent) was assessed by comparing it with conventional coronary angiography. METHODS: In-segment and in-stent restenosis (> or =50% in diameter) were evaluated in 96 stent segments in 68 patients [61+/-12 years, 51 (75%) male] using both 64-channel MDCT and conventional coronary angiography. The in-stent analysis was confined to the portion of the artery covered by the stent and the in-segment analysis included the stent and 5 mm proximal or distal to the stent edges. RESULTS: The 64-channel MDCT could evaluate stent restenosis in 93 of 96 (97%) stent segments. Quantitative conventional coronary angiography found in-segment restenosis (> or =50% in diameter) in 16 of 68 (23%) patients and 16 of 96 (17%) segments. For the patients with interpretable stent segments, the sensitivity, specificity, positive predictive value, and negative predictive value of 64-channel MDCT for in-segment restenosis per patient were 63, 96, 83, and 89%, respectively; per segment they were 63, 97, 83, and 93%, respectively; and for in-stent restenosis per stent they were 82, 98, 82, and 98%, respectively. CONCLUSIONS: The diagnostic accuracy of 64-channel MDCT for assessing stent restenosis had high specificity and negative predictive value in the clinical setting. The 64-channel MDCT may be a promising, less-invasive imaging tool for stent restenosis, especially for the purpose of excluding stent restenosis.

Clinical Predictors of Incomplete ST-Segment Resolution in the Patients With Acute ST Segment Elevation Myocardial Infarction

BACKGROUND AND OBJECTIVES: The failure of ST-segment resolution (STR) after primary percutaneous coronary intervention (pPCI) is associated with adverse clinical outcomes. However, the clinical predictors on admission for incomplete STR are poorly known. SUBJECTS AND METHODS: Patients undergoing pPCI (n=101, 79 males and 22 females, mean age 60.0 years) were divided into complete STR group (> or =70%, n=58) and incomplete STR group (<70%, n=43). The groups were compared according to clinical factors including history, electrocardiographic (ECG) patterns, angiographic features and laboratory data. RESULTS: The incomplete STR group contained more frequent hypertensive patients (p=0.04) and patients displaying longer tendency in total chest pain duration (p=0.08). This group was associated with worse clinical factors such as low ejection fraction (p=0.06), higher Killip class (p=0.08) and more death (p=0.042). Grade 3 ischemia pattern of ECG and precordial ST elevation (i,e anterior myocardial infarction) at admission were more frequent in the incomplete STR group (p=0.001 and 0.002, respectively). Initial troponin I, creatinin kinase -MB and brain natriuretic peptide levels were higher in the incomplete STR group (p=0.001, 0.002, and 0.043, respectively). Coronary angiography showed that culprit lesions were more frequent in left anterior descending artery than other arteries in the incomplete STR group of patients (p=0.002). Thrombolysis In Myocardial Infarction (TIMI) flow grades 2 or less before PCI was more frequent in the incomplete STR group (p=0.029). However, TIMI flow grade after PCI was not appreciably different between the two groups. Logistic regression analysis demonstrated that TIMI flow grade 2 or less was most powerful predictor for incomplete STR {odds ratio (OR)=12.12, 95% confidence interval (CI) 1.23-119.35, p=0.032}. Other independent predictors were anterior infarction (OR=3.39, CI 1.46-10.57, p=0.007), ischemia grade 3 ECG at admission (OR=3.87, CI 1.31-11.41, p=0.014), and hypertensive patients (OR=3.03, CI 1.13-8.15, p=0.027). CONCLUSION: Incomplete STR after pPCI is associated with poor prognostic clinical factors. TIMI flow grade 2 or less before pPCI, ST elevation on precordial leads, ischemia grade 3 pattern of initial ECG, and hypertensive patients are independent predictors for incomplete STR in the early stage.