Positive Association of Coronary Calcium Detected by Computed Tomography Coronary Angiography with Periprocedural Myocardial Infarction

Background

Periprocedural myocardial infarction (PMI) may occur in approximately 5% to 30% of patients undergoing percutaneous coronary intervention. Whether the morphology of coronary plaque calcium affects the occurrence of PMI is unknown.

Materials and Methods

A total of 616 subjects with stable angina and normal baseline cardiac troponin I levels who had undergone computed tomography angiography (CTA) were referred to elective percutaneous coronary intervention. The morphology of coronary calcium was determined by CTA analysis. PMI was defined as an elevation in 24-h post-procedural cardiac troponin I levels of > 5 times the upper limit of normal with either symptoms of myocardial ischemia, new ischemic electrocardiographic changes, or documented complications during the procedure. Logistic regression was performed to identify the effect of the morphology of coronary calcium on the occurrence of PMI.

Results

According to the presence or morphology of coronary calcium as shown by CTA, 210 subjects were grouped in the heavy calcification group, 258 in the mild calcification group, 40 in the spotty calcification group and 108 in the control group. The dissection rate was significantly higher in the heavy calcification group than in the control group (7.1 % vs. 1.9%, p = 0.03). The occurrence of PMI in the heavy calcification group was significantly higher than that in the control group (OR 4.38, 95% CI 1.80–10.65, p = 0.001). After multivariate adjustment, the risk of PMI still remained significantly higher in the heavy calcification group than in the control group (OR 4.04, 95% CI 1.50–10.89, p = 0.003).

Conclusions

The morphology of coronary calcium determined by CTA may help to predict the subsequent occurrence of PMI. A large amount of coronary calcium may be predictive of PMI.     

The Association of Brachial-Ankle Pulse Wave Velocity with Coronary Artery Disease Evaluated by Coronary Computed Tomography Angiography

The aim of this study was to investigate whether brachial-ankle pulse wave velocity (baPWV) is associated with the severity of coronary artery disease (CAD) assessed by coronary computed tomography angiography (CCTA), and to evaluate baPWV as a predictor of obstructive CAD on CCTA. A total of 470 patients who underwent both baPWV and CCTA were included. We evaluated stenosis degree and plaque characteristics on CCTA. To estimate the severity of CAD, we calculated the number of segment with plaque (segment involvement score; SIS), stenosis degree-weighted plaque score (segment stenosis score; SSS), and coronary artery calcium score (CACS). The mean baPWV was 1,485 ± 315 cm/s (range, 935-3,175 cm/s). Non-obstructive (stenosis < 50%) and obstructive (stenosis ≥ 50%) CAD was found in 129 patients (27.4%) and 144 (30.6%), respectively. baPWV in patients with obstructive CAD was higher than that of patients with non-obstructive (1,680 ± 396 cm/s versus 1,477 ± 244 cm/s, P < 0.001) or no CAD (1,680 ± 396 cm/s versus ± 196 1,389 cm/s, P < 0.001). baPWV showed significant correlation with SSS (r = 0.429, P < 0.001), SIS (r = 0.395, P < 0.001), CACS (r 0.346, P < 0.001), and the number of segment with non-calcified plaque (r 0.092, P = 0.047), mixed plaque (r = 0.267, P < 0.001), and calcified plaque (r = 0.348, P < 0.001), respectively. The optimal baPWV cut-off value for the detection of obstructive CAD was 1,547 cm/s. baPWV ≥ 1,547 cm/s was independent predictor for the obstructive CAD. In conclusion, baPWV is well correlated with the severity of CAD evaluated by CCTA. baPWV has the potential to predict severity of coronary artery atherosclerosis.     

320排CT冠脉造影检查对冠状动脉斑块成分分析可行性初探

目的:研究320排CT冠脉造影对分析冠状动脉轻度及重度狭窄患者斑块成分的价值。方法:2011年4月-2012年5月间我院1132例(62±12岁,42%女性)冠心病患者行320排CT冠状动脉造影检查,依据美国心脏协会16分段标准,分析每一例患者每一节段血管狭窄程度及斑块性质,CT斑块分型如下:Ⅰ型为钙化斑块,Ⅱ型为钙化为主的混合斑块,Ⅲ型为非钙化为主的混合斑块,Ⅳ型为非钙化斑块。比较不同狭窄程度组斑块类型差别。结果:共363例为冠脉血管正常人群,冠状动脉狭窄患者共769例,其中管腔狭窄程度<50%的轻度人群为367例,重度狭窄组(≥50%)为402例。重度狭窄患者组冠脉血管混合斑块数量较多,而非钙化斑块相对较少(Ⅰ～Ⅳ型斑块所占比例分别为22%,,39%,21%,18%),轻度狭窄患者组各斑块所占比例分别为29%,29%,26%,16%(p=0.006)。结论:随着冠状动脉狭窄程度的不同,冠状动脉粥样硬化斑块的类型也不尽相同,重度狭窄人群组中混合斑块较多而非钙化斑块较少。320排CT冠脉造影可对冠状动脉斑块成分进行分析。     

Relation between Mild to Moderate Chronic Kidney Disease and Coronary Artery Disease Determined with Coronary CT Angiography

Background

Both end-stage and milder stages of chronic kidney disease (CKD) are associated with an increased risk of adverse cardiovascular events. Several studies found an association between decreasing renal function and increasing coronary artery calcification, but it remains unclear if this association is independent from traditional cardiovascular risk factors. Therefore, the aim of this study was to investigate whether mild to moderate CKD is independently associated with coronary plaque burden beyond traditional cardiovascular risk factors.

Methods

A total of 2,038 patients with symptoms of chest discomfort suspected for coronary artery disease underwent coronary CT-angiography. We assessed traditional risk factors, coronary calcium score and coronary plaque characteristics (morphology and degree of luminal stenosis). Patients were subdivided in three groups, based on their estimated glomerular filtration rate (eGFR) Normal renal function (eGFR ≥90 mL/min/1.73 m²); mild CKD (eGFR 60–89 mL/min/1.73 m²); and moderate CKD (eGFR 30–59 mL/min/1.73 m²).

Results

Coronary calcium score increased significantly with decreasing renal function (P<0.001). Coronary plaque prevalence was higher in patients with mild CKD (OR 1.83, 95%CI 1.52–2.21) and moderate CKD (OR 2.46, 95%CI 1.69–3.59), compared to patients with normal renal function (both P<0.001). Coronary plaques with >70% luminal stenosis were found significantly more often in patients with mild CKD (OR 1.67 (95%CI 1.16–2.40) and moderate CKD (OR2.36, 95%CI 1.35–4.13), compared to patients with normal renal function (both P<0.01). After adjustment for traditional cardiovascular risk factors, the association between renal function and the presence of any coronary plaque as well as the association between renal function and the presence of coronary plaques with >70% luminal stenosis becomes weaker and were no longer statistically significant.

Conclusion

Although decreasing renal function is associated with increasing extent and severity of coronary artery disease, mild to moderately CKD is not independently associated with coronary plaque burden after adjustment for traditional cardiovascular risk factors.     

Comparison of Aortic Annulus Diameter Measurement between Multi-Detector Computed Tomography and Echocardiography: A Meta-Analysis

Background and Purpose

Accurate measurement of aortic annulus diameter is crucial for choosing suitable prosthetic size for transcatheter aortic valve implantation (TAVI). Several imaging methods are available for the measurement, but significant variability between different modalities has been observed. The purpose of this study was to systematically compare the measurements of aortic annulus diameter between multi-detector computed tomography (MDCT), transthoracic echocardiography (TTE), and transesophegeal echocardiography (TEE).

Methods

PubMed and EMBASE databases between January 2000 and January 2012 were searched. We extracted data from eligible studies evaluating the aortic annulus diameter by MDCT and echocardiography (TTE, TEE, or both). We performed a random-effects meta-analysis to calculate the weighted mean differences of aortic annulus diameter measurement between MDCT, TTE, and TEE.

Results

A total of 10 eligible studies involving 581 subjects with aortic valve stenosis were included. Aortic annulus diameter measured on coronal view by MDCT (25.3±0.52 mm) was respectively larger than that measured on sagittal view by MDCT (22.7±0.37 mm), TTE (22.6±0.28 mm), and TEE (23.1±0.32 mm). The weighted mean difference of aortic annulus diameter between coronal view by MDCT and TTE these two methods was 2.97 mm, followed by the weighted mean difference of 2.53 mm between coronal view and sagittal view by MDCT, and the mean difference of 1.74 mm between coronal view on MDCT and TEE (P<0.0001 for all). The weighted mean difference of aortic annulus diameter measurement between TEE and TTE was significant but somewhat small (0.45 mm, P = 0.007).

Conclusion

Aortic annulus diameter measured on coronal view by MDCT was robustly and significantly larger than that obtained on sagittal view by MDCT, TTE, or TEE. Such variability of aortic annulus diameter measurement by different imaging modalities cannot be ignored when developing optimal strategies for selection of prosthetic valve size in TAVI.     

Diagnosis of Coronary Heart Diseases Using Gene Expression Profiling; Stable Coronary Artery Disease,Cardiac Ischemia with and without Myocardial Necrosis

Cardiovascular disease (including coronary artery disease and myocardial infarction) is one of the leading causes of death in Europe, and is influenced by both environmental and genetic factors. With the recent advances in genomic tools and technologies there is potential to predict and diagnose heart disease using molecular data from analysis of blood cells. We analyzed gene expression data from blood samples taken from normal people (n = 21), non-significant coronary artery disease (n = 93), patients with unstable angina (n = 16), stable coronary artery disease (n = 14) and myocardial infarction (MI; n = 207). We used a feature selection approach to identify a set of gene expression variables which successfully differentiate different cardiovascular diseases. The initial features were discovered by fitting a linear model for each probe set across all arrays of normal individuals and patients with myocardial infarction. Three different feature optimisation algorithms were devised which identified two discriminating sets of genes, one using MI and normal controls (total genes = 6) and another one using MI and unstable angina patients (total genes = 7). In all our classification approaches we used a non-parametric k-nearest neighbour (KNN) classification method (k = 3). The results proved the diagnostic robustness of the final feature sets in discriminating patients with myocardial infarction from healthy controls. Interestingly it also showed efficacy in discriminating myocardial infarction patients from patients with clinical symptoms of cardiac ischemia but no myocardial necrosis or stable coronary artery disease, despite the influence of batch effects and different microarray gene chips and platforms.     

老年主动脉瓣钙化与冠心病合并心律失常的相关性探讨

目的:探讨老年患者主动脉瓣钙化与冠心病合并心律失常的相关性。方法:纳入解放军总医院疑诊为冠心病的老年住院患者276例,行冠状动脉造影,同期行超声心动图和24 h动态心电图检查,详细记录患者病史。根据超声结果,将患者分成主动脉瓣钙化(AVC)组和非主动脉瓣钙化(NAVC)组,比较两组冠心病合并心律失常的检出率,评价老年患者主动脉瓣钙化对冠心病合并心律失常的预测价值。结果:AVC组和NAVC组的年龄、吸烟史、高血压史、糖尿病史存在显著性差异(P0.05);AVC组冠心病的确诊率为93.7%,而NAVC组为80.6%,两组差异有统计学意义(P=0.002);AVC组冠心病合并心律失常检出率也显著性高于NAVC组(59.2%vs 35.1%,P=0.043)。结论:主动脉瓣钙化与冠心病合并心律失常密切相关,有望作为冠心病合并心律失常的高危患者有效的筛查指标。     

急性冠脉综合征患者GRACE评分与心功能及冠脉病变的关系研究

目的:探讨全球急性冠状动脉疾病登记(GRACE)风险评分与急性冠脉综合征(ACS)患者心功能及冠脉病变的关系。方法:回顾性分析2015年4月至2017年6月我院收治的276例ACS患者的临床资料,根据GRACE评分结果进行分组,GRACE评分140分者作为高危组(93例),GRACE评分109~140分者作为中危组(96例),GRACE评分109分者作为低危组(87例),比较三组的一般资料、生化指标、心功能指标、冠脉病变严重程度,采用Spearman相关系数分析GRACE评分与心功能指标和冠脉病变严重程度的相关性。结果:高危组和中危组男性所占比例、年龄、高血压比例、载脂蛋白-B(Apo-B)、空腹血糖(FBG)、纤维蛋白原(FIB)、胱抑素-C(Cys-C)、同型半胱胺酸(Hcy)、左心房前后径(LAAP)、左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDD)、多支血管病变所占比例以及重度狭窄和完全闭塞所占比例高于低危组,且高危组高于中危组,差异均有统计学意义(P0.05);高危组和中危组三酰甘油(TG)、载脂蛋白-A(Apo-A)、左心室射血分数(LVEF)低于低危组,且高危组低于中危组,差异均有统计学意义(P0.05)。Spearman相关系数分析显示,GRACE评分与LAAP、LVESD、LVEDD、冠脉病变血管支数、狭窄程度呈正相关关系(P0.05),GRACE评分与LVEF水平呈负相关关系(P0.05)。结论:GRACE评分越高,ACS患者的心功能越差,冠脉病变越严重,GRACE评分可以反映ACS患者的心功能水平和冠脉病变的严重程度。     

Optimizing Radiation Dose Levels in Prospectively Electrocardiogram-Triggered Coronary Computed Tomography Angiography Using Iterative Reconstruction Techniques: A Phantom and Patient Study

Aim

To investigate the potential of reducing the radiation dose in prospectively electrocardiogram-triggered coronary computed tomography angiography (CCTA) while maintaining diagnostic image quality using an iterative reconstruction technique (IRT).

Methods and Materials

Prospectively-gated CCTA were first performed on a phantom using 256-slice multi-detector CT scanner at 120 kVp, with the tube output gradually reduced from 210 mAs (Group A) to 125, 105, 84, and 63 mAs (Group B–E). All scans were reconstructed using filtered back projection (FBP) algorithm and five IRT levels (L2-6), image quality (IQ) assessment was performed. Based on the IQ assessment, Group D(120 kVp, 84 mAs) reconstructed with L5 was found to provide IQ comparable to that of Group A with FBP. In the patient study, 21 patients underwent CCTA using 120 kV, 210 mAs with FBP reconstruction (Group 1) followed by 36 patients scanned with 120 kV, 84 mAs with IRT L5 (Group 2). Subjective and objective IQ and effective radiation dose were compared between two groups.

Results

In the phantom scans, there were no significant differences in image noise, contrast-to-noise ratio (CNR) and modulation transfer function (MTF) curves between Group A and the 84 mAs, 63 mAs groups (Groups D and E). Group D (120 kV, 84 mAs and L5) provided an optimum balance, producing equivalent image quality to Group A, at the lowest possible radiation dose. In the patient study, there were no significant difference in image noise, signal-to-noise ratio (SNR) and CNR between Group 1 and Group 2 (p = 0.71, 0.31, 0.5, respectively). The effective radiation dose in Group 2 was 1.21±0.14 mSv compared to 3.20±0.58 mSv (Group 1), reflecting dose savings of 62.5% (p<0.05).

Conclusion

iterative reconstruction technique used in prospectively ECG-triggered 256-slice coronary CTA can provide radiation dose reductions of up to 62.5% with acceptable image quality.     

Tuberculosis Contact Investigation Using Interferon-Gamma Release Assay with Chest X-Ray and Computed Tomography

Between September 2009 and January 2010, 6 members of the Japanese Eastern Army, who had completed the same training program, were diagnosed with active tuberculosis (TB) on different occasions. The Ministry of Defense conducted a contact investigation of all members who had come into contact with the infected members. The purpose of this study was to verify the efficacy of the TB screening protocol used in this investigation. A total of 884 subjects underwent interferon-gamma release assay (IGRA) and chest X-ray. The 132 subjects who were IGRA positive or with X-ray findings suggestive of TB subsequently underwent chest computer tomography (CT). Chest CT was performed for 132 subjects. Based on CT findings, 24 (2.7%) subjects were classified into the active TB group, 107 (12.1%) into the latent tuberculosis infection (LTBI) group, and 753 (85.2%) into the non-TB group. The first 2 groups underwent anti-TB therapy, and all 3 groups were followed for 2 years after treatment. Although one subject in the active TB group experienced relapse during the follow-up period, no patient in the LTBI or non-TB groups developed TB. IGRA and chest X-ray, followed by chest CT for those IGRA positive or with suspicious X-ray findings, appears to be an effective means of TB contact screening and infection prevention.     

Aortic and Cardiac Structure and Function Using High-Resolution Echocardiography and Optical Coherence Tomography in a Mouse Model of Marfan Syndrome

Marfan syndrome (MFS) is an autosomal-dominant disorder of connective tissue caused by mutations in the fibrillin-1 (FBN1) gene. Mortality is often due to aortic dissection and rupture. We investigated the structural and functional properties of the heart and aorta in a [Fbn1^C1039G/+] MFS mouse using high-resolution ultrasound (echo) and optical coherence tomography (OCT). Echo was performed on 6- and 12-month old wild type (WT) and MFS mice (n = 8). In vivo pulse wave velocity (PWV), aortic root diameter, ejection fraction, stroke volume, left ventricular (LV) wall thickness, LV mass and mitral valve early and atrial velocities (E/A) ratio were measured by high resolution echocardiography. OCT was performed on 12-month old WT and MFS fixed mouse hearts to measure ventricular volume and mass. The PWV was significantly increased in 6-mo MFS vs. WT (366.6 ± 19.9 vs. 205.2 ± 18.1 cm/s; p = 0.003) and 12-mo MFS vs. WT (459.5 ± 42.3 vs. 205.3 ± 30.3 cm/s; p< 0.0001). PWV increased with age in MFS mice only. We also found a significantly enlarged aortic root and decreased E/A ratio in MFS mice compared with WT for both age groups. The [Fbn1^C1039G/+] mouse model of MFS replicates many of the anomalies of Marfan patients including significant aortic dilation, central aortic stiffness, LV systolic and diastolic dysfunction. This is the first demonstration of the direct measurement in vivo of pulse wave velocity non-invasively in the aortic arch of MFS mice, a robust measure of aortic stiffness and a critical clinical parameter for the assessment of pathology in the Marfan syndrome.     

Cost-Effectiveness of New Cardiac and Vascular Rehabilitation Strategies for Patients with Coronary Artery Disease

Objective

Peripheral arterial disease (PAD) often hinders the cardiac rehabilitation program. The aim of this study was evaluating the relative cost-effectiveness of new rehabilitation strategies which include the diagnosis and treatment of PAD in patients with coronary artery disease (CAD) undergoing cardiac rehabilitation.

Data Sources

Best-available evidence was retrieved from literature and combined with primary data from 231 patients.

Methods

We developed a Markov decision model to compare the following treatment strategies: 1. cardiac rehabilitation only; 2. ankle-brachial index (ABI) if cardiac rehabilitation fails followed by diagnostic work-up and revascularization for PAD if needed; 3. ABI prior to cardiac rehabilitation followed by diagnostic work-up and revascularization for PAD if needed. Quality-adjusted-life years (QALYs), life-time costs (US $), incremental cost-effectiveness ratios (ICER), and gain in net health benefits (NHB) in QALY equivalents were calculated. A threshold willingness-to-pay of $75 000 was used.

Results

ABI if cardiac rehabilitation fails was the most favorable strategy with an ICER of $44 251 per QALY gained and an incremental NHB compared to cardiac rehabilitation only of 0.03 QALYs (95% CI: −0.17, 0.29) at a threshold willingness-to-pay of $75 000/QALY. After sensitivity analysis, a combined cardiac and vascular rehabilitation program increased the success rate and would dominate the other two strategies with total lifetime costs of $30 246 a quality-adjusted life expectancy of 3.84 years, and an incremental NHB of 0.06 QALYs (95%CI:−0.24, 0.46) compared to current practice. The results were robust for other different input parameters.

Conclusion

ABI measurement if cardiac rehabilitation fails followed by a diagnostic work-up and revascularization for PAD if needed are potentially cost-effective compared to cardiac rehabilitation only.     

Quantification of Calcium Amount in a New Experimental Model: A Comparison between Ultrasound and Computed Tomography

Purpose

Calcification is an important prognostic factor in aortic valve stenosis. However, there is no ultrasound (US) method available to accurately quantify calcification in this setting to date. We aimed to validate a new US method for measuring the amount of calcium in an in vitro model, and compare it to computed tomography (CT), the current imaging gold standard.

Materials and Methods

An agar phantom (2% agar) was made, containing 9 different amounts of calcium-hydroxyapatite Ca₅(PO₄)₃OH (2 to 50mg). The phantoms were imaged with micro-CT and US (10 MHz probe). The calcium area (area_calcium) and its maximum pixel value (PV_max) were obtained. These values were summed to calculate CT and US calcium scores (∑(area_calcium × PV_max)) and volumes (∑area_calcium). Both US- and CT-calcium scores were compared with the calcium amounts, and with each other.

Results

Both calcium scores correlated significantly with the calcium amount (R² = 0.9788, p<0.0001 and R² = 0.8154, p<0.0001 for CT and US respectively). Furthermore, there was a significant correlation between US and CT for calcium volumes (R² = 0.7392, p<0.0001) and scores (R² = 0.7391, p<0.0001).

Conclusion

We developed a new US method that accurately quantifies the amount of calcium in an in vitro model. Moreover it is strongly correlated with CT.     

Using Multidetector Computed Tomography in a Swine Model to Assess the Effects of Sublingual Nitroglycerin and Intravenous Adenosine on Epicardial Coronary Arteries

This study examines the effects of intravenous infusion of adenosine and sublingual nitroglycerin on coronary angiograms obtained by current-generation multidetector computed tomography. We assessed coronary vasodilation at baseline and after intravenous adenosine (140 µg/kg/min) or sublingual nitroglycerin spray (800 µg) in 7 female swine (weight, 40.9 ± 1.4 kg) by using electrocardiogram-gated coronary angiography with a 64-detector scanner (rotation time, 400 ms; 120kV; 400 mA) and intravenous contrast (300 mg/mL iohexol, 4.5 mL/s, 2 mL/kg). Cross-sectional areas of segments in the left anterior descending, circumflex, and right coronary arteries were evaluated in oblique orthogonal views. Images were acquired at an average heart rate of 73 ± 11 beats per minute. Changes in aortic pressure were not significant with nitroglycerin but decreased (approximately 10%) with adenosine. Of the 76 segments analyzed (baseline range, 2 to 39 mm²), 1 distal segment could not be assessed after adenosine. Segment cross-sectional area increased by 11.3% with nitroglycerin but decreased by 9.6% during adenosine infusion. The results of the present study are consistent with the practice of using sublingual nitroglycerin to enhance visualization of epicardial vessels and suggest that intravenous adenosine may hinder coronary artery visualization. This study is the first repeated-measures electrocardiogram-gated CT evaluation to use the same imaging technology to assess changes in coronary cross-sectional area before and after treatment with a vasodilator. The nitroglycerin-associated changes in our swine model were modest in comparison with previously reported human studies.Abbreviations: LAD, left anterior descending artery; MDCT, multidetector computed tomographyRecent advances in multidetector computed tomography (MDCT) for coronary angiography, their increased availability, and the pending release of a new generation of CT scanners contribute to this methodology''s potential for revolutionizing the early diagnosis and functional assessment of coronary artery disease.^15,16,25 However, the benefits of methodologic advances do not diminish the need to validate and assess the safety, efficacy, and costs of technology.¹⁵ In this regard, the present study uses an animal model with coronary anatomy analogous to that of humans^11,43 to assess the effects of sublingual nitroglycerin and intravenous adenosine on coronary epicardial vessel visualization by using baseline imaging as a control. The radiation exposure associated with CT procedures precludes human studies that involve repeated measures on the same subjects.Sublingual nitroglycerin is hypothesized to enhance the visualization of epicardial coronary vessels due to its vasodilatory properties.^8-10 Nitroglycerin acts as a nitric oxide generator to induce relaxation of vascular smooth muscle independent of endothelial function.^1,18,20 Current evidence supporting improved coronary visualization with sublingual nitroglycerin is derived from clinical cross-sectional studies that compare results in different groups of patients with heterogeneous coronary lesions.^5,6,16,27,44 A recent survey reported that more than 80% of facilities in the United States routinely use nitroglycerin in cardiac MDCT angiography.²³In contrast to the action of nitroglycerin on epicardial vascular smooth muscle, intravenous adenosine frequently is used as a pharmacologic stress to affect vasodilatation within the coronary microcirculation.²⁰ Although current-generation CT scanners have limited capability to assess myocardial tissue perfusion, research efforts from advanced imaging centers suggest that future-generation CT scanners soon will permit myocardial perfusion imaging.^13,14,29 No studies to date have assessed epicardial vessel changes by MDCT with intravenous doses of adenosine appropriate for myocardial perfusion imaging.The objective of this study was to provide an animal model for MDCT studies that permits repeated measures of epicardial vessels without the limitations of cross-sectional designs or the complications of heterogeneity of vascular lesions within clinical populations. This study used routes of administration of nitroglycerin and adenosine that are consistent with clinical practice.     

Visualization of Coronary Wall Atherosclerosis in Asymptomatic Subjects and Patients with Coronary Artery Disease Using Magnetic Resonance Imaging

Background

Magnetic resonance imaging (MRI) is sensitive to early atherosclerotic changes such as positive remodeling in patients with coronary artery disease (CAD). We assessed prevalence, quality, and extent of coronary atherosclerosis in a group of healthy subjects compared to patients with confirmed CAD.

Methodology

Twenty-two patients with confirmed CAD (15M, 7F, mean age 60.4±10.4 years) and 26 healthy subjects without history of CAD (11M, 15F, mean age 56.1±4.4 years) underwent MRI of the right coronary artery (RCA) and vessel wall (MR-CVW) on a clinical 1.5T MR-scanner. Wall thickness measurements of both groups were compared.

Principal Findings

Stenoses of the RCA (both < and ≥50% on CAG) were present in all patients. In 21/22 patients, stenoses detected at MRI corresponded to stenoses detected with conventional angiography. In 19/26 asymptomatic subjects, there was visible luminal narrowing in the MR luminography images. Fourteen of these subjects demonstrated corresponding increase in vessel wall thickness. In 4/26 asymptomatic subjects, vessel wall thickening without luminal narrowing was present. Maximum and mean wall thicknesses in patients were significantly higher (2.16 vs 1.92 mm, and 1.38 vs 1.22 mm, both p<0.05).

Conclusions

In this cohort of middle-aged individuals, both patients with stable angina and angiographically proven coronary artery disease, as well as age-matched asymptomatic subjects. exhibited coronary vessel wall thickening detectable with MR coronary vessel wall imaging. Maximum and mean wall thicknesses were significantly higher in patients. The vast majority of asymptomatic subjects had either positive remodeling without luminal narrowing, or non-significant stenosis.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00456950","term_id":"NCT00456950"}}NCT00456950     

Coronary Computed Tomography Angiography Based Assessment of Endothelial Shear Stress and Its Association with Atherosclerotic Plaque Distribution In-Vivo

Purpose

The relationship between low endothelial shear stress (ESS) and coronary atherosclerosis is well established. ESS assessment so far depended on invasive procedures. The aim of this study was to demonstrate the relationship between ESS and coronary atherosclerosis by using non-invasive coronary computed tomography angiography (CTA) for computational fluid dynamics (CFD) simulations.

Methods

A total number of 7 consecutive patients with suspected coronary artery disease who received CTA and invasive angiography with IVUS analysis were included in this study. CTA examinations were performed using a dual-source scanner. These datasets were used to build a 3D mesh model. CFD calculations were performed using a validated CFD solver. The presence of plaque was assumed if the thickness of the intima-media complex exceeded 0.3 mm in IVUS. Plaque composition was derived by IVUS radiofrequency data analysis.

Results

Plaque was present in 32.1% of all analyzed cross-sections. Plaque prevalence was highest in areas of low ESS (49.6%) and high ESS (34.8%). In parts exposed to intermediate-low and intermediate-high ESS few plaques were found (20.0% and 24.0%) (p<0.001). Wall thickness was closely associated with local ESS. Intima-media thickness was 0.43±0.34mm in low and 0.38±0.32mm in high ESS segments. It was significantly lower when the arterial wall was exposed to intermediate ESS (0.25±0.18mm and 0.28 ± 0.20mm) (p<0.001). Fibrofatty tissue was predominately found in areas exposed to low ESS (p≤0.023).

Conclusions

In this study a close association of atherosclerotic plaque distribution and ESS pattern could be demonstrated in-vivo. Adding CFD analysis to coronary CTA offers the possibility to gather morphologic and physiologic data within one non-invasive examination.     

不同年龄段冠心病患者的临床特征及其危险因素分析

目的:探讨不同年龄段冠心病(CAD)患者的临床特征,并对其危险因素进行分析。方法:采用回顾性研究,选择2010-2014年于我院冠状动脉造影并行介入治疗的冠心病患者480例,其中老年患者(A组)320例,中青年患者(B组)160例。分析两组患者的临床资料、冠状动脉病变情况、疾病类型及术后不良反应发生率,比较两组实验室检查指标,将上述差异有统计学意义的因素带入多元线性回归,分析冠心病的危险因素。结果:(1)A组与B组之间,在性别构成及是否患有高血压病方面比较,差异有统计学意义(P0.05)。(2)A组的单支病变以及三支病变者发生率较B组高,差异有统计学意义(P0.05)。A组患者术后总的不良发生率较中B组多,其中出血、心律失常、心源性休克的发生率也均较中青年组高,差异有统计学意义(P0.05)。(3)A组患者的肌酐(Cr)、血浆凝血酶原时间(PT)、纤维蛋白原(FIB)水平高于B组,谷氨酰转肽酶(GGT)、三酰甘油(TG)、同型半胱氨酸(Hcy)、血小板计数(PLT)水平低于B组,且差异有统计学意义(P0.05)。(4)多因素Logistic回归分析显示,Hcy、FIB是冠心病的危险因素(P0.05)。结论:老年与中青年冠心病患者的临床表现有较大不同,且Hcy、FIB是影响不同年龄段冠心病发病的危险因素,提示在临床治疗冠心病过程中治疗方案应存在一定差异。