Hidemasa Tanaka

Direct Measurement of Wall Stiffness for Carotid Arteries by Ultrasound Strain Imaging

OBJECTIVE The elastic properties of the carotid arterial wall have not been directly characterized in the clinical setting. Strain rate (SR) imaging is a newly developed echocardiographic method developed for imaging the tissue motion of the myocardium. The purpose of this study was to directly estimate the elastic properties of the carotid artery by using SR imaging in patients with coronary artery disease (CAD). METHODS A total of 135 patients with CAD, 15 age-matched controls, and 35 young healthy subjects had a carotid ultrasound examination for measuring the values of SR and strain of the carotid artery. The intima-media thickness and distensibility coefficient of the carotid artery were estimated. RESULTS Age and Framingham risk score were significantly related to SR and strain, respectively (r = 0.62-0.67, all P < .001). These strain measurements were significantly correlated with distensibility coefficient and intima-media thickness, respectively (r = 0.30-0.56, all P < .001). Similar values of the areas under the receiver operating characteristic curves were obtained among Framingham risk score (0.70 +/- 0.05), SR (0.67 +/- 0.05), and strain (0.73 +/- 0.05). CONCLUSION This study demonstrated that the elastic properties of the carotid artery wall were directly characterized by using SR imaging in patients with CAD.

Comparison of 64-slice multi-detector computed tomography coronary angiography between asymptomatic, type 2 diabetes mellitus and impaired glucose tolerance patients.

BACKGROUND Cardiovascular disease is the most frequent cause of death and disability for diabetic patients, and patients with diabetes are more likely to have silent ischemia. Multi-detector computed tomography (MDCT) allows non-invasive assessment of coronary artery stenosis and plaque properties. In this study, we investigated whether 64-slice MDCT can non-invasively identify significant coronary artery stenosis in asymptomatic, type 2 diabetes mellitus (T2DM) and impaired glucose tolerance (IGT) patients. METHODS AND RESULTS The study population consisted of 154 consecutive asymptomatic patients [IGT (n=93), T2DM (n=61)]. All patients underwent contrast-enhanced 64-slice MDCT. The number of diseased coronary segments was classified as showing obstructive (> or = 50% luminal narrowing) disease or not. Significant coronary stenosis was detected in 43 (27.9%) of 154 enrolled patients. Patients with T2DM showed significantly more coronary stenosis than patients with IGT (41% vs. 19.4%; p<0.01). Twenty-three patients [14.9%; IGT (n=9), T2DM (n=14)] underwent percutaneous coronary intervention (PCI) for severe stenosis. Patients with T2DM showed significantly more calcified plaque than IGT (47.5% vs. 29%; p<0.05), but not significantly more soft plaque (19.7% vs. 15.1%; ns), or significantly different remodeling index (1.05+/-0.18 vs. 1.04+/-0.21; ns), respectively. CONCLUSIONS 64-Slice MDCT can non-invasively identify significant coronary artery stenosis in asymptomatic, T2DM and IGT patients.

Positive correlation between coronary arterial remodelling and prodromal angina in acute myocardial infarction

Recently, the relation between coronary arterial remodelling and ischaemic coronary disease has become a focus of investigation.1 Positive coronary arterial remodelling has been shown to be more frequent in acute coronary syndromes, including acute myocardial infarction (AMI), whereas negative remodelling has been shown to be more frequent in stable angina.2 However, in the case of AMI, preceding clinical presentations of the onset vary among patients and it is well known that patients often undergo episodes of unstable or stable angina.3 Furthermore, no studies have correlated remodelling and the presence of prodromal symptoms. In this study intravascular ultrasound (IVUS) was performed before coronary intervention to evaluate the possible correlation between the arterial remodelling at the culprit lesion site of AMI and the prodromal symptoms. Ninety four consecutive patients presenting with their first AMI were considered for entry into this study. AMI was diagnosed on the basis of coronary angiography, ECG, prolonged chest pain (> 30 minutes), and subsequent elevation of creatine kinase. Twenty two of these patients were excluded because of either an inability to make the IVUS catheter pass across the lesion before angioplasty (n  =  5), no proximal reference site defined due to a large side branch (n  =  4), or poor ultrasound image quality (n  =  13). Finally, 72 patients (60 men, …