Predictors of statin-induced regression of left anterior descending coronary artery wall thickness as measured by high-resolution transthoracic echocardiography

BACKGROUND: Statin therapy has been shown to reduce cardiovascular risk after myocardial infarction (MI). Using a novel technique of high-resolution transthoracic echocardiography (HRTTE), we sought to assess the statin-induced changes in left anterior descending coronary artery (LAD) wall thickness in previously statin naive patients over a 12-month period. METHOD AND RESULTS: Thirty subjects underwent HRTTE assessment of their LAD wall thickness predischarge post-MI (non-LAD territory) and at 3, 6, and 12 months. The LAD anterior and posterior wall thickness and vessel luminal diameter were measured. Blood lipid levels were also assessed at each study visit. All subjects were started on moderate lipid-lowering therapy (40 mg of atorvastatin or simvastatin). There was a sustained decrease in total cholesterol (-23%), triglycerides (-19%), and low-density lipoprotein (-41%) at the 3-month visit from the baseline, with no change in high-density lipoprotein level. Overall, there was no change in the LAD wall thickness and external or vessel lumen diameter over the 12-month period. Of those that demonstrated regression, the only predictor of percentage change in the LAD wall thickness was the baseline LAD wall thickness. Conclusion: Despite a favorable change in blood lipid profile, no overall change in the LAD wall thickness was detected over a 12-month period in subjects on moderate statin therapy using HRTTE. However, using case-based analysis, regression was able to be predicted by the baseline LAD wall thickness. HRTTE may be an instructive noninvasive modality to assess response to statin intervention.     

Changes in left anterior descending coronary artery wall thickness detected by high resolution transthoracic echocardiography

Recently, it has been demonstrated that high-resolution transthoracic echocardiography (HRTTE) is able to detect differences in the wall thickness of the left anterior descending coronary artery (LAD) between patients with coronary artery disease (CAD) and normal volunteers. The aim of this study was to further validate this technique. One hundred ten volunteers, 58 patients with angiographically proved CAD and 52 control subjects, underwent assessments of their LADs using HRTTE. Anterior and posterior wall thicknesses differed between subjects in the CAD group and controls (1.9 +/- 0.6 vs 1.2 +/- 0.3 mm, p <0.001, and 1.8 +/- 0.5 vs 1.2 +/- 0.3 mm, p <0.001, respectively). External LAD diameter was also greater in subjects in the CAD group compared with controls (5.2 +/- 1.9 vs 4.4 +/- 0.9 mm, respectively, p = 0.01). However, there was no difference in luminal diameter between subjects in the CAD group and the controls (1.9 +/- 0.9 vs 2.1 +/- 0.8 mm, respectively, p = 0.3). In conclusion, HRTTE demonstrated that LAD wall thicknesses and external diameters in patients with CAD were significantly larger than in normal volunteers. Luminal diameter, however, was maintained in the 2 groups, indicating that subjects in the CAD group had undergone positive remodeling at the site measured. This objectively visualized evidence of coronary atherosclerosis with HRTTE would likely be undetected during coronary angiography.     

Measurement of epicardial fat thickness by transthoracic echocardiography for predicting high-risk coronary artery plaques

Epicardial adipose tissue (EAT) volume is reported to be associated with coronary plaques. We evaluated whether non-invasive measurement of EAT thickness by echocardiography can predict high-risk coronary plaque characteristics determined independently by coronary computed tomography (CT) angiography. We enrolled 406 patients (mean age 63 years, 57 % male) referred for 64-slice CT. EAT was measured on the right ventricle free wall from a parasternal long-axis view at the end of systole. High-risk coronary plaques were defined as low-density plaques (<30 Hounsfield units) with positive remodeling (remodeling index >1.05). Patients were divided into thin or thick EAT groups using a cutoff value derived from receiver operator characteristic curve analysis for discriminating high-risk plaques. The receiver operator characteristic cutoff value was 5.8 mm with a sensitivity of 83 % and specificity of 64 % (area under the curve 0.77, 95 % confidence interval 0.70–0.83, p < 0.01). Compared with the thin EAT group, the thick EAT group had a high prevalence of low-density plaques (4 vs. 24 %, p < 0.01), positive remodeling (39 vs. 60 %, p < 0.01), and high-risk plaques (3 vs. 17 %, p < 0.01). Multiple logistic analysis revealed that thick EAT was a significant predictor of high-risk plaques (odds ratio 7.98, 95 % confidence interval 2.77–22.98, p < 0.01) after adjustment for covariates, including conventional risk factors, visceral adipose tissue area, and medications. The measurement of EAT thickness by echocardiography may provide a non-invasive option for predicting high-risk coronary plaques.     

Comparison of high-frequency two-dimensional transthoracic echocardiography versus intravascular ultrasound for evaluation of the left anterior descending coronary artery

The purpose of this study was to evaluate the feasibility of high-frequency transthoracic echocardiography for measuring the wall thickness and luminal area of the left anterior descending coronary artery (LAD). Fifteen patients underwent simultaneous high-frequency transthoracic echocardiography and intravascular ultrasound (IVUS) examinations. There were good agreements for wall thickness (0.38 +/- 0.05 vs 0.38 +/- 0.06 mm, p = 0.0004) and luminal area (3.24 +/- 1.05 vs 3.32 +/- 1.34 mm2, p <0.0001) between high-frequency transthoracic echocardiography and IVUS measurements. High-frequency transthoracic echocardiography was reliable in the measurement of the wall thickness and luminal area of the LAD.     

经胸超声心动图测量心脏外膜脂肪厚度与老年冠心病患者的相关性研究

目的评价经胸超声心动图(TTE)测量心脏外膜脂肪(EAT)厚度与老年冠心病患者的相关性和预测价值。方法将77例年龄≥60岁的患者根据冠状动脉造影诊断分为冠心病组57例和非冠心病组20例。TTE测量EAT厚度,比较2组临床资料及EAT厚度的差异,并利用logistic回归模型和ROC曲线分析EAT厚度与冠心病的关系及诊断价值。结果冠心病组EAT厚度明显高于非冠心病组[(5.26±1.77)mmvs(3.60±1.03)mm,P=0.000)]。冠心病组EAT厚度≥4.14mm比例明显高于非冠心病组(71.9%vs 25.0%,P=0.000)。logistic回归分析显示,EAT厚度增加(OR=6.009,95%CI:1.436~25.148,P=0.014)是冠心病的1项独立危险因素。EAT厚度≥4.14 mm诊断冠心病的敏感性为71.9%,特异性为75.0%,ROC曲线下面积为0.783(95%CI:0.678~0.889,P<0.01)。结论老年人采用TTE测量的EAT厚度与冠心病发生密切相关,其可作为老年冠心病筛查的一种有效的无创检查方法。     

Usefulness of coronary flow reserve measured by transthoracic coronary Doppler ultrasound to detect severe left anterior descending coronary artery stenosis

Transthoracic coronary Doppler ultrasound during venous adenosine infusion showed damped (<1) coronary flow velocity reserve in patients with severe left anterior descending coronary artery stenosis. Damped coronary flow reserve discriminated severe from nonsevere stenosis with high sensitivity, specificity, and positive predictive accuracy, and is a unique noninvasive tool to identify high-risk patients.     

经胸彩色多普勒检测冠心病患者冠状动脉左前降支和右冠状动脉远端血流储备

目的评价经胸彩色多普勒超声心动图(TTDE)检测冠状动脉前降支(LAD)和右冠状动脉后降支(PDA)血流储备和开放程度的可行性。方法65例(男48例,女17例)连续临床诊断或疑似冠心病患者,平均年龄(58±14)岁,左室射血分数(49±8)%,用TTDE冠状动脉显像方式于心尖两腔切面显示LAD和PDA远端的血流,在基础状态和持续静脉注射腺苷(140μg·kg-1·min-1)情况下分别测定其冠状动脉血流储备(CFR),结果与冠状动脉造影对比。结果所有患者基础和充血状态LAD血流均得到显示(其中4例应用造影剂),55例患者PDA得到显示(5例应用造影剂),有2例患者PDA闭塞,因此LAD的检测成功率为100%(65/65),PDA的CFR检测成功率为87%(55/63),所有患者腺苷静脉注射时间均少于4min,CFR检测平均时间为(7.3±1.6)min。以CFR≤2.0和CFR≤1.8分别作为判断冠状动脉狭窄(≥50%)和显著狭窄(≥70%)的标准,准确性相近,诊断LAD和RCA狭窄的灵敏度、特异度和ROC曲线下面积分别为89%/93%,86%/84%,0.89/0.92,诊断显著狭窄的灵敏度、特异度和ROC曲线下面积分别为88%/89%,90%/83%,0.94/0.95。结论经胸多普勒超声心动图检测LAD和PDA成功率和诊断冠状动脉狭窄的准确性均较高,有重要临床价值。     

Potential use of high-resolution two-dimensional transthoracic echocardiography for visualization of the left anterior descending coronary artery

High-resolution, two-dimensional transthoracic echocardiography (HR-2DTTE) can detect the difference in the left anterior descending coronary artery (LAD) wall thickness between patients with coronary artery disease and patients with normal coronary arteries. However, HR-2DTTE measurements of the LAD wall thickness are larger than measurements obtained by intravascular ultrasound and histology. This difference may be due to the inclusion of adventitia by HR-2DTTE. We evaluated the contribution of adventitia to the wall thickness of the normal and atherosclerotic LAD by comparing HR-2DTTE with high-frequency epicardial echocardiography. The LAD wall thickness was significantly greater in patients with coronary artery disease by both HR-2DTTE and high-frequency epicardial echocardiography. Both an increase in the intima plus media thickness and an increase in the thickness of adventitia contributed to the increase in the LAD wall thickness in patients with coronary artery disease. Adventitia represents a significant portion of the LAD wall thickness imaged by HR-2DTTE and its thickness increases significantly with the development of atherosclerosis.     

Assessment of intermediate stenosis in the left anterior descending coronary artery with contrast-enhanced transthoracic Doppler echocardiography

BACKGROUND: Visual or quantitative assessment of coronary angiography may not exactly predict the physiological significance of intermediate (40-70%) coronary stenosis. Coronary flow reserve is a well-established marker of the functional significance of coronary stenosis. OBJECTIVES: The aim of this study was to compare the coronary flow velocity reserve (CFVR) using contrast-enhanced transthoracic Doppler echocardiography (CE-TTDE) with thallium-201 imaging in assessment of intermediate lesions in the left anterior descending coronary artery (LAD). METHODS: A consecutive series of 50 patients with intermediate stenosis in the LAD underwent pharmacological stress thallium-201 imaging and CFVR measured by CE-TTDE. RESULTS: CFVR could be measured in 49 of 50 patients by the present method. A CFVR <2.0 predicted the presence of a stress thallium defect in 12 of 14 patients (agreement=90%, kappa=0.76, P < 0.001). The sensitivity and specificity of CFVR for stress thallium-201 results were 86 and 91%, respectively. In contrast, significant stenosis (>50% by diameter) showed fair agreement for stress thallium defects (agreement=59%, kappa=0.28, P < 0.05). CONCLUSIONS: In the evaluation of intermediate lesions in the LAD, CFVR as assessed by CE-TTDE could accurately predict the presence of ischemia on stress thallium imaging, whereas angiographic stenosis did not yield reliable results.     

超声测量心外膜脂肪组织厚度与冠心病的相关性研究

目的 评价心外膜脂肪组织厚度(EAT)与冠心病(CHD)的相关性及其诊断预测价值.方法 共298例符合入选标准的对象行冠状动脉造影,符合CHD诊断标准的200例为CHD组,余98例为对照组,通过经胸彩色多普勒超声心动图测量EAT,用SPSS 17.0软件进行数据分析,比较两组EAT差异.结果 CHD组EAT大于对照组[(5.44±1.50)mm比(4.52±1.31)mm,P＜0.01];EAT与CHD呈正相关(OR=1.598);EAT诊断CHD的受试者工作特征曲线下面积:男性为0.67,诊断敏感度59％,特异度82％,诊断切点值为5.06 mm;女性为0.71,诊断敏感度58％,特异度72％,诊断切点值为4.88 mm.结论 EAT是CHD的一个独立危险因素,经胸彩色多普勒超声心动图测量EAT可以作为CHD预测评估的一个有效指标.     

Prediction of wall motion recovery from the left anterior descending coronary artery velocity pattern recorded by transthoracic doppler echocardiography in patients with anterior wall myocardial infarction retrospective and prospective studies

The diastolic deceleration slope of coronary flow velocity is steeper in patients with substantial 'no reflow' phenomenon than in those without it. This study investigated whether functional outcomes in patients with anterior wall acute myocardial infarction (AMI) can be predicted by analyzing the coronary flow velocity pattern recorded with transthoracic Doppler (TTD) echocardiography. Coronary blood flow velocity in the distal left anterior descending coronary artery was recorded with TTD at day-2 after primary percutaneous transluminal coronary angioplasty/Stent in 51 patients with anterior AMI and the diastolic deceleration half time (DHT, ms) was measured. The wall motion score index (WMSI) was measured at day-1 and -21. In the retrospective study, the DHT was much shorter in those with a poor outcome than in those with good outcome (152 +/- 109 vs 395 +/- 128 ms, p<0.05). Receiver-operating characteristic analysis documented that DHT > or = 300 ms is a suitable cut-off point (sensitivity of 83% and specificity of 93%). In the prospective study (n=30), AWMSI(dl-d21) was significantly higher in those with a DHT > or = 300 ms than those without (0.3 > or = 0.5 vs 1.6 > or = 0.7, p<0.001). DHT correlated significantly with AWMSI(dl-d21) (r=0.76, p<0.001). Patients with a shorter DHT of diastolic coronary flow velocity have a poorer functional outcome among patients with anterior AMI. The TTD-determined DHT is a useful predictor of myocardial viability after an anterior AMI.     

Noninvasive assessment of coronary flow reserve in the left anterior descending artery by transthoracic echocardiography before and after stenting

BACKGROUND: Noninvasive assessment of coronary flow reserve in the left anterior descending artery (LAD) by transthoracic Doppler echocardiography (TTDE) has been already validated as a new method for determining the degree of stenosis over the proximal flow. OBJECTIVES: The aim of the study is to determine, by TTDE, the feasibility and the value of the coronary flow reserve (CFR) (defined as the maximal increase in coronary blood flow above its basal pressure for a given perfusion pressure when coronary circulation is maximally dilated) in the mid-to-distal LAD before and after percutaneous angioplasty and to demonstrate the early recovery of microvascular tone immediately after stenting. METHODS: The study population consisted of 36 patients with significant isolated LAD stenosis (70-90%) identified by coronary angiography. CFR was recorded in the mid-to-distal LAD at rest and during hyperemia obtained after adenosine intravenous infusion before and after stenting. RESULTS: Adequate visualization of the LAD was obtained in 25 out of 36 patients (70%). At rest the mean CFR was 1.5132 +/- 0.33 (1.1-2.58). However, after stenting the mean CFR was significantly higher: 2.18 +/- 0.55 (1.3-3.8), with P <0.01. CONCLUSIONS: CFR can be easily determined by TTE in approximately 70% of patients. Noninvasive Doppler echocardiography shows impaired CFR in patients with LAD disease. After stenting CFR is restored, demonstrating early recovery of microvascular tone. These results are comparable to those published in the same conditions. Larger series with a long-term follow-up may allow identifying patients at high risk for restenosis after stenting.     

Noninvasive detection of total occlusion of the left anterior descending coronary artery with transthoracic Doppler echocardiography.

OBJECTIVES: The purpose of this study was to evaluate the value of transthoracic Doppler echocardiography (TTDE) for the noninvasive detection of total left anterior descending coronary artery (LAD) occlusion. BACKGROUND: Total coronary occlusion is associated with an adverse long-term prognosis, and mechanical revascularization may be required for the patient with total coronary occlusion. However, a noninvasive diagnosis of total coronary occlusion before coronary angiography (CAG) has been difficult, especially in patients without clinical signs. METHODS: We studied 103 consecutive patients who underwent CAG for the evaluation of coronary artery disease. The study group consisted of 16 patients with total LAD occlusion (group A) and 87 patients without total LAD occlusion (group B). Coronary flow velocity in the mid-portion of the LAD was recorded by TTDE. RESULTS: Adequate spectral Doppler recordings of diastolic flow in the LAD were obtained in 98 study patients (95%; 15 patients in group A and 83 patients in group B). In group A, retrograde LAD flow was obtained in 14 (93%) of 15 patients. The mean diastolic velocity of the retrograde flow was 21.0 +/- 6.1 cm/s. In group B, antegrade LAD flow was obtained in all 83 patients (100%). The mean diastolic velocity of the antegrade flow was 21.5 +/- 7.1 cm/s. Retrograde LAD flow by TTDE had a sensitivity of 93% and a specificity of 100% for the detection of total LAD occlusion. CONCLUSIONS: Retrograde flow in the LAD by TTDE is a highly sensitive and specific finding that can be used to noninvasively diagnose total LAD occlusion.     

Yield of transthoracic echocardiography with high frequency transducer in the study of the anterior descending coronary artery

INTRODUCTION AND OBJECTIVES: This study was performed to evaluate the feasibility and utility of a transthoracic high frequency transducer to detect and measure the left anterior descending coronary artery flow in patients with lesions in this artery or anterior myocardial infarction. MATERIALS AND METHODS: We studied 11 subjects with lesions greater than 75% and another 10 with anterior myocardial infarction. We compared the results with a control group of 18 subjects. An ATL HDI 5000 ultrasound unit with a 5-8 MHz transducer was used to identify the left anterior descending in the anterior interventricular sulcus from an apical four chamber window. We considered that left anterior descending was detected when a diastolic predominant flow pattern was obtained with pulse Doppler. RESULTS: Left anterior descending was detected in 37/39 of cases (94.4%). Patients with coronary lesions showed a decrease in the limit of significance in the diastolic/systolic peak velocity ratios: 2.5 (SD 0.7) vs 1.8 (SD 0.3) with a p = 0.024. Patients with anterior myocardial infarction obtained lower diastolic/systolic peak velocity ratios than controls: 2.5 (SD 0.7) vs 1.4 (SD 0.3) with a p = 0.001. CONCLUSIONS: Left anterior descending coronary artery flow can be assessed by transthoracic high frequency echocardiography in greater than 90% of the cases. Patients with coronary lesions and those with anterior myocardial infarction have a decreased diastolic/systolic peak velocity ratio.     

Usefulness of transthoracic color Doppler echocardiography for the identification of left anterior descending coronary artery stenosis.

We briefly describe our experience with transthoracic Doppler echocardiography for the direct evaluation of mid-distal left anterior descending coronary artery (LAD) stenosis. Three patients with previous myocardial infarction, scheduled for coronary flow reserve evaluation, underwent Doppler analysis of the mid-distal LAD. In all 3 cases, the mid-distal LAD stenosis was accurately quantified by the Doppler spectrum as confirmed by quantitative coronary angiography. Our study demonstrated the feasibility of transthoracic Doppler echocardiography in the discrimination of significant and non-significant mid-distal LAD stenosis. Limitations of such a technique could be related to the variable coronary anatomy and to the severity of the atherosclerotic process.     

Improving feasibility of posterior descending coronary artery flow recording by transthoracic Doppler echocardiography.

AIMS: Recording coronary arteries' flow by transthoracic Doppler echocardiography (TTDE) is a new task. Despite several studies concerning the left anterior descending artery (LAD) exist, the same for posterior descending coronary artery (PD) do not. Reported feasibility is not more than 76%. The aim of the study was to try to improve feasibility by using an additional two-dimensional view as a guide. METHODS AND RESULTS: PD flow recording was performed in 35 consecutive unselected patients under the guidance of the usual two-dimensional modified view [a two-chamber view (2-C)], and with a new four-chamber modified view (4-C). A semi-quantitative growing-quality score (from 0 to 3 points) to the trace was given. Contrast enhancement was used if PD was not visualized without it. The overall feasibility was 80%. A good or very good velocity signal (TTDE score > or = 2) was observed in 48% of patients without contrast enhancement. Time for first visualization of PD was short and significantly lower in 2-C than in 4-C (66 +/- 39 vs 90 +/- 70 s, respectively, P<0.05). CONCLUSIONS: TTDE recording of PD flow gained better feasibility being guided by two views. Maximal time for first visualization of PD was less than 3 min.     

Left anterior descending artery length in left and right coronary artery dominance

BACKGROUND: Coronary stenosis of the left anterior descending artery (LAD) is respected by cardiologists because of its negative influence on morbidity and mortality. An important anatomical consideration is the length of the LAD. OBJECTIVE: To investigate the relationship between length of LAD and coronary dominance. DESIGN: Retrospective comparison of 100 consecutive angiograms with left coronary dominance with 100 consecutive angiograms with right coronary dominance. The relationship between the length of the LAD and coronary dominance was analyzed. METHODS: We retrospectively compared 100 consecutive angiograms with left coronary dominance (the posterior descending artery being supplied by the circumflex artery) with 100 consecutive angiograms with right coronary dominance (the posterior descending artery being supplied by the right coronary artery). LADs were categorized into three types: type A, LAD terminating before the cardiac apex; type B, LAD reaching the apex but not supplying the inferoapical segment of the left ventricle; and type C, LAD wrapping around the apex and supplying the inferoapical segment. LAD typing was also analyzed in relation to gender. RESULTS: It was found that the LAD wrapped around the apex in 87% of cases of left coronary dominance but only in 47% of patients with right coronary dominance, and that the long LADs were more frequently seen in women than in men, irrespective of coronary dominance. CONCLUSIONS: We found that the LAD in left coronary dominance is usually long and wraps around the apex, and believe that angiographic interventions in such cases have important clinical significance.     

Noninvasive quantitative evaluation of the patency of internal mammary artery grafts to the left anterior descending coronary artery by transthoracic Doppler echocardiography

OBJECTIVES: Evaluation of left anterior descending coronary artery (LAD) flow by transthoracic Doppler echocardiography (TTDE) may allow assessment of anastomosis of the internal mammary artery (IMA) grafted to the LAD. This study tested the feasibility of TTDE to evaluate anastomotic stenosis of the IMA grafted to the LAD. METHODS: TTDE was performed in 66 patients (48 men and 18 women, mean age 67 +/- 10 years) with left or right IMA grafts to the LAD. The distal IMA flow at the anastomosis was visualized and the percentage stenosis was evaluated by the continuity equation using the anastomotic and pre-anastomotic flow velocity measured by TTDE as well as by angiography. If the anastomotic flow was not visualized by TTDE, the absence of augmented diastolic flow of the proximal IMA, by using the supraclavicular approach, with diastolic to systolic mean velocity ratio < 0.25 was considered as anastomotic occlusion. RESULTS: Anastomotic flow was visualized and the percentage stenosis was obtained by the continuity equation in 50 patients. In 4 of the remaining 16 patients, the proximal IMA flow by TTDE showed the occlusion pattern. In these 54 (82%) patients, the percentage stenosis by TTDE showed a significant correlation with that by angiography (r2 = 0.86, p < 0.0001). In all the remaining 12 patients with the patent proximal IMA pattern but without visualized anastomotic flow, the patency was confirmed by angiography. CONCLUSIONS: TTDE enables direct visualization and quantitative evaluation of the anastomotic patency in patients with IMA graft to the LAD.