Anatomic Coronary Artery Disease Research Articles

Triple Rule Out: Why It Is Not Ready to Roll Out

Triple Rule Out: Why It Is Not Ready to Roll Out

Aspirin in primary prevention: can we individualize care?

Coronary computed tomography (CT) angiography is a noninvasive and accurate diagnostic tool to detect coronary artery disease (CAD), and is increasingly utilized in clinical practice. However, anatomical information from coronary CT angiography does not always provide accurate insight into whether the stenosis causes clinically significant ischemia. With a concern that widespread use of coronary CT angiography may result in excess referral of patients to invasive coronary angiography and unnecessary revascularization of non-ischemic coronary lesions, novel methods were developed to evaluate both anatomic and functional aspects of coronary stenosis. Several studies suggested that CT assessment of myocardial stress perfusion is feasible and improves the diagnostic accuracy of coronary CT angiography in the detection of hemodynamically significant stenosis. Cardiac CT protocol including both coronary CT angiography and stress/rest myocardial perfusion can simultaneously evaluate anatomical CAD and its physiological consequences. However, significant radiation exposure and a larger volume of iodinated contrast administration are required for additional perfusion imaging. Computational fluid dynamics, as applied to coronary CT angiography, enables prediction of blood flow and pressure in coronary arteries, and calculation of lesion-specific fractional flow reserve (FFR). CT-derived FFR (FFRCT) was reported to have a high diagnostic performance for detection and exclusion of ischemia-causing stenosis. Since the calculation of FFRCT is performed on simulated hyperemia, it does not require modification of typical coronary CT angiography protocols, does not require the administration of additional medication and does not confer any additional radiation. CT myocardial perfusion imaging and CT-derived computed FFR represent significant advances in the field of cardiac CT, with the ability to combine anatomical data from CT angiography together with the physiologic significance of anatomical stenosis. Such non-invasive anatomic-functional testing prior to intervention may improve patient outcomes and reduce costs. Further clinical studies are needed prior to widespread clinical adoption of these diagnostic techniques.

Evidence for Medical Management Versus Revascularization for Coronary Artery Disease: Guidance from Cardiac Magnetic Resonance Imaging and Computed Tomography

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in developed countries.1 The reatment of CAD has been revolutionized during the past everal decades; however, appropriate patient selection for reatment is of paramount importance. Treatment of CAD, hether by medical therapy or revascularization, depends on variety of factors including patients’ symptoms, long-term isk and likelihood of procedural success. Key diagnostic ests add to the history and physical examination in guiding reatment. The traditional cornerstone of CAD assessment ad been stress testing, either with electrocardiography EKG) alone or in combination with echocardiography or uclear scintigraphy. Although counterintuitive, it is now accepted that detecion of anatomical CAD does not imply hemodynamically ignificant disease that requires revascularization. Stress testng provides data on the physiology of CAD. Recent advanceents in computed tomography angiography (CTA) and ardiac magnetic resonance imaging (MR) have provided cliicians with alternative diagnostic tools. CTA and MR both rovide functional and anatomical data, yet each modality as its own strengths and weaknesses. CTA noninvasively rovides detailed anatomical information but requires ionizng radiation. MR’s strength lies in improved functional data nd myocardial tissue characterization but has long scan imes and limitations imposed by claustrophobia and MRncompatible implants. Both modalities have shown technial advances in mitigating the limitations of irregular cardiac hythms, breath holding difficulty, and extensive calcium or etallic artifacts.

Stable angina in women: lessons from the National Heart, Lung and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation

The paradoxical sex difference in which women have lower rates of anatomical coronary artery disease (CAD) but worsening symptoms, ischemia, and outcomes appears to be linked to a sex-specific pathophysiology of coronary reactivity, which includes microvascular dysfunction. For women with obstructive CAD, their risk is elevated compared with men, yet women are less likely to receive guideline-indicated therapies. For women with evidence of ischemia but no obstructive CAD, antianginal and antiischemic therapies can ameliorate symptoms, improve endothelial function and quality of life; however, trials aimed to improve outcomes are needed. Thus, ischemic heart disease (IHD) in women presents a unique and difficult challenge for clinicians due to a greater symptom burden, functional disability, higher healthcare costs, and more adverse outcomes as compared with men, despite a lower prevalence and severity of obstructive CAD, which remains the current focus of therapeutic strategies. Continued research is indicated to devise therapeutic regimens to improve symptom burden and reduce risk in women with IHD.

Predicting clinically unrecognized coronary artery disease: use of two- dimensional echocardiography

Background2-D Echo is often performed in patients without history of coronary artery disease (CAD). We sought to determine echo features predictive of CAD.Methods2-D Echo of 328 patients without known CAD performed within one year prior to stress myocardial SPECT and angiography were reviewed. Echo features examined were left ventricular and atrial enlargement, LV hypertrophy, wall motion abnormality (WMA), LV ejection fraction (EF) < 50%, mitral annular calcification (MAC) and aortic sclerosis/stenosis (AS). High risk myocardial perfusion abnormality (MPA) was defined as >15% LV perfusion defect or multivessel distribution. Severe coronary artery stenosis (CAS) was defined as left main, 3 VD or 2VD involving proximal LAD.ResultsThe mean age was 62 ± 13 years, 59% men, 29% diabetic (DM) and 148 (45%) had > 2 risk factors. Pharmacologic stress was performed in 109 patients (33%). MPA was present in 200 pts (60%) of which, 137 were high risk. CAS was present in 166 pts (51%), 75 were severe. Of 87 patients with WMA, 83% had MPA and 78% had CAS. Multivariate analysis identified age >65, male, inability to exercise, DM, WMA, MAC and AS as independent predictors of MPA and CAS. Independent predictors of high risk MPA and severe CAS were age, DM, inability to exercise and WMA.2-D echo findings offered incremental value over clinical information in predicting CAD by angiography. (Chi square: 360 vs. 320 p = 0.02).Conclusion2-D Echo was valuable in predicting presence of physiological and anatomical CAD in addition to clinical information.

How Low-Risk Is a Coronary Calcium Score of Zero?

Coronary artery calcium (CAC) scoring by computed tomography (CT) has been the subject of intense interest and critical scrutiny since it was first reported as a clinical tool in 1990.1 With improvements in study design, greater availability of coronary CT scanners, and increased attention to the posttest prognosis of patient samples and asymptomatic individuals who have undergone coronary CT, CAC measurement is now considered a potentially useful test for improving coronary risk assessment in selected intermediate-risk asymptomatic patients in whom high CAC scores signify increased cardiovascular risk beyond that predicted by conventional cardiovascular risk factors alone.2 Article p 1693 At the other end of the spectrum, does a very low CAC score signify very low risk? An American Heart Association writing group3 stated that a CAC score of zero (CAC=0; ie, no calcified plaque detected) indicated 1) that the presence of atherosclerotic plaque, including unstable or vulnerable plaque, was highly unlikely; 2) that the presence of significant luminal obstructive disease was highly unlikely (negative predictive value on the order of 95% to 99%); and 3) that the risk of a cardiovascular event in the next 2 to 5 years was quite low (0.1 per 100 person-years). In addition, at least 1 early study suggested that CAC=0 might be useful in the emergency room setting as a tool to rule out myocardial ischemia in symptomatic patients.4 A recent review article5 suggested the same conclusions. However, as pointed out by a different …

Comparison of computed tomographic angiography versus rubidium-82 positron emission tomography for the detection of patients with anatomical coronary artery disease

The present study compared computed tomographic coronary angiography (CTA) and positron emission tomography (PET) for the detection of significant anatomical coronary artery stenosis as defined by conventional invasive coronary angiography (CICA). The study protocol was approved by the local ethics board, and informed consent was obtained from all patients. Of the 26 patients (mean age 57+/-9 years, 18 men) who prospectively underwent CTA and rubidium-82 PET before CICA, 24 patients had a history of chest pain. Images were interpreted by expert readers and assessed for the presence of anatomically significant coronary stenosis (50% luminal diameter stenosis or greater) or myocardial perfusion defects. Diagnostic test characteristics were analyzed using patient-based, territory-based, vessel-based and segment-based analyses. In the 24 patients referred for chest pain, CTA had similar sensitivity to PET, but was more specific (sensitivity 95% [95% CI 72% to 100%] versus 95% [95% CI 72% to 100%], respectively; specificity 100% [95% CI 46% to 100%] versus 60% [95% CI 17% to 93%], respectively) in the detection of patients with anatomical coronary artery stenosis of 50% or greater. On a per-segment basis of all 26 patients, CTA had a sensitivity, specificity, positive predictive value and negative predictive value of 72%, 99%, 91% and 95%, respectively, in all coronary segments. Coronary CTA has a similar sensitivity and specificity to rubidium-82 PET for the identification of patients with significant anatomical coronary artery disease.

Clinical Myocardial Perfusion PET/CT

The field of nuclear cardiology is witnessing growing interest in the use of cardiac PET for the evaluation of patients with coronary artery disease (CAD). The available evidence suggests that myocardial perfusion PET provides an accurate means for diagnosing obstructive CAD, which appears superior to SPECT especially in the obese and in those undergoing pharmacologic stress. The ability to record changes in left ventricular function from rest to peak stress and to quantify myocardial perfusion (in mL/min/g of tissue) provides an added advantage over SPECT for evaluating multivessel CAD. There is growing and consistent evidence that gated myocardial perfusion PET also provides clinically useful risk stratification. Although the introduction of hybrid PET/CT technology offers the exciting possibility of assessing the extent of anatomic CAD (CT coronary angiography) and its functional consequences (ischemic burden) in the same setting, there are technical challenges in the implementation of CT-based transmission imaging for attenuation correction. Nonetheless, this integrated platform for assessing anatomy and biology offers a great potential for translating advances in molecularly targeted imaging into humans.

New Technology for Noninvasive Evaluation of Coronary Artery Disease

Cardiac computed tomography (CT) and positron emission tomography (PET) are emerging as powerful noninvasive imaging tools for the evaluation of atherosclerosis in patients with known or suspected coronary artery disease (CAD). Unlike invasive coronary angiography, CT coronary angiography (CTA) not only assesses disease within the coronary lumen but can also provide direct qualitative and quantitative information about nonobstructive atherosclerotic plaque burden within the vessel wall. Thus, it is possible that CTA-based patient evaluation may provide more clinically relevant information on which to base risk assessments compared with conventional “lumenography.” On the other hand, PET is rapidly growing as a powerful and efficient alternative to conventional single-photon emission CT (SPECT) imaging to evaluate regional myocardial perfusion and metabolism in patients with CAD. In addition, PET scanners are now being converted to hybrid PET/CT devices, which, in the setting of CAD, offer the potential for a comprehensive noninvasive cardiac evaluation of anatomy and function. This review will discuss current and potential future applications of cardiovascular CT, PET, and hybrid PET/CT, with a particular focus on ischemic heart disease. The information provided by noninvasive imaging generally falls into 1 of 3 categories: myocardial perfusion, left ventricular (LV) function, or coronary artery anatomy. The clinical utility, value, and role of a noninvasive modality are based on 2 test characteristics: What type of information is provided (eg, stress perfusion, stress and/or rest LV function, coronary anatomy), and what is the accuracy of the information provided. For example, SPECT and PET both provide stress and rest perfusion information, but the latter will be a superior clinical tool if the imaging data better represent the actual defect size and are subject to less artifact. The advantage of PET over SPECT will be further enhanced, as will be discussed later, if it provides additional clinically relevant information not …

Apolipoprotein L-I is positively associated with hyperglycemia and plasma triglycerides in CAD patients with low HDL

Apolipoprotein L-I (apoL-I) is present on a subset of HDL particles and is positively correlated with plasma triglycerides (TGs). We measured plasma apoL-I levels in coronary artery disease (CAD) subjects with low HDL who were enrolled in an angiographic CAD prevention trial. At baseline, apoL-I levels (n = 136; range, 2.2-64.1 mug/ml) were right skewed with a large degree of variability. Multivariate analysis for biological determinants of apoL-I revealed that the log of VLDL-TG (+0.17; P < 0.05) and hyperglycemia (HG; +0.26; P < 0.005) independently predicted apoL-I level. Hyperglycemic patients (n = 24) had mean apoL-I levels >50% higher than normoglycemic subjects (n = 112; 13.2 vs. 8.3 mug/ml, respectively; P < 0.001). No relationship between apoL-I level and change in CAD was found (r = 0.06, P = 0.49). Simvastatin-niacin therapy did not alter apoL-I levels (n = 34; P = 0.27), whereas antioxidant vitamins alone increased apoL-I by >50% (n = 36; P < 0.01). Genotyping of a known apoL-I polymorphism (Lys166Glu) did not independently account for any of the variability in apoL-I levels. In conclusion, we found TG and HG to be the strongest predictors of apoL-I within a dyslipidemic CAD population. These data provide further characterization of the novel HDL-associated apoL-I.

Diagnostic accuracy of seismocardiography compared with electrocardiography for the anatomic and physiologic diagnosis of coronary artery disease during exercise testing

A multicenter study was performed to compare the diagnostic accuracy of a new technique, Seismocardiography, with that of electrocardiography for physiologically and anatomically significant ischemic coronary artery disease (CAD) during exercise stress testing. Five participating centers enrolled 129 patients who had simultaneous seismocardiograms and 12-lead electrocardiograms at the time of their exercise treadmill stress tests. Two different definitions of CAD were used: anatomic and physiologically significant disease. The presence of anatomically significant CAD (≥50% diameter stenosis) was documented by coronary angiography. Physiologically significant CAD was defined as present in the same 129 patients when coronary arteriography (≥50% diameter stenosis) and thallium-201 scintigraphy (defect on initial postexercise images) were both abnormal. Seismocardiography had a significantly better sensitivity for detecting anatomic CAD than did electrocardiography (73 vs 48%; p < 0.001), without loss of specificity (78 vs 80%; p = NS). Exercise seismocardiography added significant incremental diagnostic information beyond that provided by exercise electrocardiography. Seismocardiography was more sensitive (without less specificity) in women and in patients who did not achieve maximal predicted heart rate. In patients with physiologically significant CAD, the seismocardiogram was also significantly more sensitive (78%) than was the electrocardiogram (55%) (p < 0.02), without loss of specificity (84 vs 74%). Seismocardiography significantly improved sensitivity for the detection of anatomic and physiologic CAD. It is easy to perform and may be a clinically useful adjunct in exercise stress testing.

Accuracy of exercise 201Tl myocardial scintigraphy in asymptomatic young men.

Little is known about the diagnostic usefulness of 201Tl scintigraphy for detecting asymptomatic coronary artery disease in apparently healthy men. We thus evaluated planar 201Tl exercise myocardial scintigraphy in 845 asymptomatic male military aircrew undergoing coronary arteriography because of abnormal noninvasive tests suggesting possible myocardial ischemia. Patients were stratified by prior disease risk into six subgroups using age (< 45 and > or = 45 years) and ratio of total to high density lipoprotein cholesterol (< 4.5, 4.5-6.0, and > 6.0). Significant coronary artery disease (> or = 50% diameter stenosis in any major coronary artery) was present in 143 (16.9% prevalence). Overall sensitivity and specificity of 201Tl scintigraphy adjusted for verification bias were estimated to be 45 +/- 4% and 78 +/- 1%, respectively. These values are lower than corresponding values accepted for clinical populations. Positive and negative predictive values varied across subgroups. A normal thallium scan indicated low risk of disease, but an abnormal test was likely to be a false-positive result. A logistic equation was retrospectively fit to the data for estimating the probability of disease given age, cholesterol ratio, and thallium results. Within each quintile of estimated risk, the average risk did not differ significantly from the observed disease prevalence. Exercise 201Tl scintigraphy is limited by the frequent occurrence of false-positive tests in detecting asymptomatic, anatomic coronary artery disease in young men in accordance with Bayesian probability theory.

Noninvasive definition of anatomic coronary artery disease by ultrafast computed tomographic scanning: A quantitative pathologic comparison study

Objectives. The aim of this study was to determine the relation between coronary artery calcification detected by ultrafast computed tomographic scanning and histopathologic coronary artery disease.Background. Recent studies suggest that discrete coronary artery calcification as visualized by ultrafast computed tomographic scanning may facilitate the noninvasive detection of estimation, or both, of the in situ extent of coronary disease. Such quantitative relations have not been established.Methods. Thirteen consecutive perfusion-fixed outopsy hearts (from eight male and five female patients aged 17 to 83 years) were scanned by ultrafast computed tomographic scanning in contiguous 3-mm tomographic sections. The major epicardial arteries were dissected free, positioned longitudinally and scanned again in cross section. Coronary artery calcification in a coronary segment was defined as the presence of one or more voxels with a computed tomographic density 130 Hounsfleld units. Each epicardial artery was sectioned longitudinally, stained and measured with a planimeter for quantification of cross-sectional and atherosclerotic plaque areas at 3-mm intervals, corresponding to the computed tomographic scans. A total of 522 paired coronary computed tomographic and histologic sections were studied.Results. Direct relations were found between ultrafast computed tomographic scanning coronary artery calcium burden and atherosclerotic plaque area and percent lumen area stenosis. However, the range for plaque area or percent lumen stenosis, or both, associated with a given calcium burden was broad. Three hundred thirty-one coronary segments showed no calcification by computed tomography. Although atherosclerotic disease was found in several corresponding pathologic specimens,97% of these noncalcified segments were associated with nonobstructive disease (<75% area stenosis); if no calcification was determined in an entire coronary vessel, all corresponding coronary disease was found to be nonobstructive. To determine the relation between arterial calcification and any atheromatous disease, computed tomographic calcium burden for each segment was paired with the histologic absence or presence of disease. Ultrafast computed tomographic scanning had a sensitivity and specificity of 59% and 90% and a negative and positive predictive value of 65% and 87%, respectively. A direct correlation was found (r = 0.99) between total calcium burden calculated from tomographic scans of the heart as a whole and scans of the arteries obtained in cross section.Conclusions. The detection of coronary calcification by ultrafast computed tomographic scanning is highly predictive of the presence of histopathologic coronary disease, but the use of this technique to define the extent of coronary disease may be limited. However, the absence of coronary calcification at any site is highly specific for the absence of obstructive disease.

Non-invasive detection of anatomic coronary artery disease by ultrafast CT: A quantitative pathologic study

Non-invasive detection of anatomic coronary artery disease by ultrafast CT: A quantitative pathologic study

Total cholesterol/HDL ratio is the best predictor of anatomic coronary artery disease among elderly patients

Total cholesterol/HDL ratio is the best predictor of anatomic coronary artery disease among elderly patients

Total cholesterol/HDL ratio is the best predictor of anatomic coronary artery disease in women

Total cholesterol/HDL ratio is the best predictor of anatomic coronary artery disease in women

Relationship between lipid values and anatomic coronary artery disease in patients with total cholestrol below 200 mg/dl

Relationship between lipid values and anatomic coronary artery disease in patients with total cholestrol below 200 mg/dl

Ventricular ectopy in totally symptom-free subjects with defined coronary artery anatomy

Ambulatory ECG recordings were obtained from 313 consecutive, totally symptom-free male subjects on whom cardiac catheterization was subsequently performed for occupational reasons. These recordings were examined for ventricular ectopy and the results were studied in relation to the findings on selective coronary angiography. Ventricular ectopy was a common finding, with 58% of those subjects with normal coronary artery anatomy having at least one ventricular premature beat during the period of monitoring (mean 16 1 2 hours), 22% having greater than one such complex per hour, and 10% having greater than 10 per hour. Complex ventricular ectopy was present in 21% of the normal subjects. No association between the extent or complexity of ventricular ectopy and the presence or grade of anatomic coronary artery disease was demonstrated, nor was ventricular ectopy overrepresented in those with both significant coronary artery disease on angiography and evidence of ischemia on provocative testing.

Refractory symptomatic ventricular tachycardia and ventricular fibrillation in elderly patients

The problem of refractory life-threatening ventricular tachyarrhythmias in elderly patients has not been previously studied. To determine if clinical, anatomic, or electrophysiologic variables and prognosis are significantly different in elderly subjects, 49 elderly (68 to 84 years) and 44 younger (44 to 53 years) survivors of refractory symptomatic ventricular tachycardia and/or ventricular fibrillation secondary to coronary artery disease were studied. Elderly patients displayed more extensive anatomic coronary artery disease, with 80 percent having three-vessel disease in comparison with 30 percent of the younger patients (p <0.001). Prior myocardial infarction, heart failure, and cardiomegaly were more common in the elderly group (p <0.01, p <0.001, and p <0.034, respectively), whereas angina was more common in the younger group (p <0.001). In 55 percent of the elderly patients and 58 percent of the younger patients, electrophysiologic testing demonstrated inducible sustained ventricular tachycardia that required treatment with an investigative antiarrhythmic drug and/or cardiac surgery, including implantation of an automatic defibrillator. Elderly patients tolerated aggressive evaluation as well as did younger patients, and despite the difference in clinical and anatomic findings, long-term survival curves were similar, although the probability of survival at 20 months was 62 percent in the elderly and 80 percent in the younger patients. This difference in early survival is explained by eight surgical deaths in the elderly group, compared with two in the younger group.

Role of isosorbide dinitrate in patients with unstable angina pectoris

The development of hemodynamic facilities permitted observations after isosorbide dinitrate (ISDN) administration over a 4-hour period in patients with a history of unstable angina pectoris and documented anatomic coronary artery disease. The patients had no evidence of left ventricular failure and were free of pain during the period of sublingual and oral ISDN administration. Beneficial influences on venous return and arterial blood pressure were manifested as declines in preload and afterload, along with reduction in the mechanical work of the ventricle and, finally, increases in the diastolic compliance of the ventricle. These hemodynamic changes were shown to persist 8 to 12 times as long as the brief influence of nitroglycerin. Thus hemodynamic evidence was provided for the first time on the beneficial influence of oral and sublingual ISDN on venous, arterial, and left ventricular myocardial muscle in patients with unstable angina pectoris.