End-systolic and end-diastolic left atrial volume assessment by two-dimensional echocardiography: a comparison study with magnetic resonance imaging.

BACKGROUND: The left atrial volume (LAV) is an important indicator of the severity of certain diseases, and measuring LAV through the cardiac cycle may enable the evaluation of various left atrium (LA) functional parameters. The results of two-dimensional (2D) echocardiographic LAV measurement methods vary, and no technique is accepted as being optimal. OBJECTIVE: This study compared the accuracy of end-systolic and end-diastolic LAV measurements by 2D echocardiography with those obtained by magnetic resonance imaging (MRI). METHODS: Fifty consecutive patients who underwent both echocardiography and MRI due to clinical reasons with nonselective cardiac disease were studied. LAVs by 2D echocardiography were obtained with the prolate ellipsoid (PE), biplane area-length (AL), and modified Simpson's (MS) methods. RESULTS: End-systolic and end-diastolic LAVs calculated by each method correlated significantly with MRI results (P < 0.0001). The prolate ellipsoid method provided LAVs that most correlated with MRI results, and the biplane area-length and modified Simpson's methods provided LAVs with small mean differences (<5 ml) compared to MRI results. CONCLUSION: All three methods of 2D echocardiographic LAV measurement provide valuable LAV data, suggesting the possibility of evaluating various LA functional parameters.

Mechanical dyssynchrony assessed by speckle tracking imaging as a reliable predictor of acute and chronic response to cardiac resynchronization therapy.

Speckle tracking echocardiography (STE) has the potential to detect the heterogeneous initiation of active myocardial contraction, which is the primary cause of left ventricular (LV) systolic dysfunction in patients with mechanical dyssynchrony. This study was designed to assess the ability to predict response to cardiac resynchronization therapy (CRT) of STE-derived dyssynchrony parameters in comparison with invasive hemodynamic assessments. Thirty patients referred for CRT were studied. The time difference of first peak (Td-(first peak)) and the maximum peak (Td-(max peak)) on the radial strain-time curves of the earliest and the latest segments were measured as the dyssynchrony parameter. Peak positive dP/dt (dP/dt(max)) was measured as the indicator of global LV systolic performance. CRT responders were defined as patients with LV end-systolic volume reduction greater than 15% at 3 months after CRT. CRT increased the dP/dt(max) compared with the baseline study (P < .001). Percent changes in the dP/dt(max) (dP/dt(max)) were significantly correlated with Td-(first peak) (R = 0.743, P < .001), but weakly correlated with Td-(max peak) (R = 0.390, P = .03). Twenty patients (66%) were identified as chronic CRT responders. Receiver operating characteristics analysis revealed that Td-(first peak) shared a similar ability with dP/dt(max) to detect chronic responders (Td-(first peak) >167.0 ms, area under the curve [AUC] 0.945; dP/dt(max) >16.2%, AUC 0.934) compared with Td-(max peak) (>194.5 ms, AUC 0.820). STE-derived Td-(first peak) showed a reliable ability to predict the acute and chronic response to CRT as well as dP/dt(max).

Effect of hospital case volume on treatment and in-hospital outcomes in patients undergoing percutaneous coronary intervention for acute myocardial infarction. Results from the Ibaraki Coronary Artery Disease Study (ICAS) Registry.

The volume of percutaneous coronary interventions (PCI) performed in a hospital has been suggested to correlate with favorable outcomes in patients undergoing primary PCI for acute myocardial infarction (AMI). However, studies that use current data and compare treatment and outcomes for AMI among hospitals with different volumes are still limited in Japan. Between January 2004 and March 2006, 401 AMI patients underwent primary PCI in the 11 hospitals participating in the Ibaraki Coronary Artery Disease Study (ICAS). Clinical characteristics, treatment, and in-hospital outcomes were retrospectively compared between 254 patients admitted to high-volume PCI hospitals and 147 patients admitted to low-volume hospitals. Low-volume hospitals had a higher prevalence of multivessel disease patients. High-volume hospitals had longer onset-to-door times, which were offset by faster door-to-balloon times. Rates of coronary stent use and successful PCI were comparable between the groups. Low-volume hospitals more frequently performed intra-aortic balloon pumping. Length of stay was longer in low-volume hospitals, whereas in-hospital mortality, bypass surgery, and repeat PCI rates did not differ between groups. Although the present study assessed limited data based on small sample size, we observed that contemporary standard treatments including stent implantation were performed for AMI patients undergoing primary PCI in hospitals with both high and low case volumes. We did not find an obvious relationship between hospital PCI volume and in-hospital outcomes in our data. However, further prospective surveys should be attempted to confirm these results.

Echolucent carotid plaques as a feature in patients with acute coronary syndrome.

BACKGROUND: Carotid arterial ultrasound examination may be helpful for screening populations at high risk for acute coronary syndrome (ACS), so the present study was designed to identify the carotid arterial characteristics of patients with ACS. METHODS AND RESULTS: Carotid ultrasound examinations were performed in 172 patients with ACS, 166 patients with stable coronary artery disease (CAD), and 96 control subjects. Common carotid arterial structures were assessed by the intima - media thickness (IMT), interadventitial diameter (IAD), lumen diameter (LD), the IMT to LD ratio (IMT/LD), and the plaque burden based on the plaque score. Plaque morphology was assessed by the echogenecity based on the gray-scale median (GSM). IMT, IAD, IMT/LD, and plaque score did not differ between the ACS and stable CAD groups. The GSM in the ACS group was lower (47.5+/-25.3, p<0.001) than in the control (70.1+/-22.5) and stable CAD (73.7+/-23.4) groups. Multiple logistic regression analysis showed that the presence of carotid echolucent plaques (GSM

Macrophage metalloelastase accelerates the progression of atherosclerosis in transgenic rabbits.

BACKGROUND: Macrophage metalloelastase (matrix metalloproteinase [MMP]-12) is upregulated in atherosclerotic lesions and aneurysm; thus, increased MMP-12 activity may play an important role in the pathogenesis of atherosclerosis. However, the pathological roles of MMP-12 in the initiation and progression of atherosclerosis have not been defined. METHODS AND RESULTS: We compared the susceptibility of MMP-12 transgenic (Tg) rabbits to cholesterol-rich diet-induced atherosclerosis with that of non-Tg littermate rabbits. The rabbits were maintained at either relatively lower levels of hypercholesterolemia for shorter periods or higher levels of hypercholesterolemia for longer periods through a diet containing different amounts of cholesterol. We found no significant difference in the aortic atherosclerotic lesion size or quality between Tg and non-Tg rabbits at lower hypercholesterolemia. At higher hypercholesterolemia for longer periods, however, Tg rabbits developed more extensive atherosclerosis in the aortas and coronary arteries than did non-Tg rabbits. Histological examinations revealed that atherosclerotic lesions of Tg rabbits contained prominent macrophage infiltration associated with marked disruption of the elastic lamina in the tunica media with occasional formation of aneurysm-like lesions. Furthermore, increased expression of MMP-12 derived from macrophages was associated with elevated expression of MMP-3, suggesting that MMP-12 may play a pivotal role in the cascade activation of other MMPs, thereby exacerbating extracellular matrix degradation during the progression of atherosclerosis. CONCLUSIONS: Overexpression of MMP-12 causes accelerated atherosclerosis in Tg rabbits. These results suggest that macrophage-derived MMP-12 participates in the progression of atherosclerosis.

Relationship between mitral annular calcification and severity of carotid atherosclerosis in patients with symptomatic ischemic cerebrovascular disease.

OBJECTIVES: Many studies have reported the association between mitral annular calcification (MAC) and stroke. MAC has been speculated to be a direct embolic source of stroke. Recently, the association between MAC and atherosclerosis in the coronary artery, aorta, and carotid artery has been reported. This prospective study investigated the association between MAC and severity of carotid atherosclerosis in patients with symptomatic ischemic cerebral disease to evaluate the association between MAC and atherosclerosis as a cause of stroke. METHODS: We studied 377 patients with ischemic cerebral disease (253 men, 124 women, mean age 68 +/- 11 years) who underwent echocardiography to determine the presence of MAC and carotid ultrasonography to determine the severity of carotid atherosclerosis. Plaque score was the sum of the maximum intimamedia thickness in the common carotid region, the bifurcation bulb region, and the internal carotid artery region, including both right and left arteries. RESULTS: MAC was found in 86 patients, and was more frequent in women, the elderly, and patients with diabetes or hyperlipidemia (p < 0.05). Plaque score was higher in patients with than without MAC (8.3 +/- 5.8 vs 5.2 +/- 5.2 mm, p < 0.001). Multivariate regression analysis identified MAC (r = 0.26, p < 0.0001), female sex (r = -0.12, p = 0.03), and age (r = 0.23, p < 0.0001) as independently associated with plaque score. CONCLUSIONS: MAC is independently associated with severity of carotid atherosclerosis in patients with symptomatic ischemic cerebral disease. This association suggests MAC may be indirectly related to cerebrovascular disease as a marker of the presence of progressive arteriosclerosis for thromboemboli causing stroke.

Effect of age on carotid arterial intima-media thickness in childhood.

To investigate relationships between carotid arterial intima-media thickness (IMT) and age in childhood, we performed high-resolution carotid arterial ultrasonography in 60 healthy children (27 boys, 33 girls; age range, 5-14 years) determined by screening to have no dyslipidemia or hypertension. No plaque formation was found, and irregularity of IMT (root mean square roughness of IMT) did not correlate with age. Mean IMT increased in a linear manner with age [IMT in millimeters = (0.009 x age in years) + 0.35] ( r = 0.39, P = 0.002). This correlation remained significant after adjustment for gender, parental smoking, systolic and diastolic blood pressure, body mass index, and serum concentrations of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. None of these known cardiovascular disease risk factors in adults had a significant relationship with age-adjusted IMT in children. While circumferential wall stress and diastolic blood pressure were not correlated with age, mean IMT and lumen diameter showed significant positive relationships with circulating blood volume, which was calculated as the function of height and weight. These data suggested that age-dependent physiologic thickening of arterial walls begins in childhood.