Epicardial adipose tissue attenuation on computed tomography in women with coronary microvascular dysfunction: A pilot, hypothesis generating study.

BACKGROUND: Patients with myocardial ischemia without obstructive coronary artery disease often have coronary microvascular dysfunction (CMD) and associated increased risk of cardiovascular (CV) events and anginal hospitalizations. Epicardial adipose tissue (EAT) covers much of the myocardium and coronary arteries and when dysfunctional, secretes proinflammatory cytokines and is associated with CV events. While oxidative stress and systemic inflammation are associated with CMD, the relationship between EAT and CMD in women is not well known. METHODS: Women diagnosed with CMD (n = 21) who underwent coronary computed tomography with coronary artery calcium (CAC) scoring were compared to a reference group (RG) of women referred for CAC screening for preventive risk assessment (n = 181). EAT attenuation (Hounsfield units (HU)) was measured adjacent to the proximal right coronary artery, along with subcutaneous adipose tissue (SCAT). Two-sample t-tests with unequal variances were utilized. RESULTS: Mean age of the CMD group was 56 ± 8 years and body mass index (BMI) was 31.6 ± 6.8 kg/m2. CV risk factors in the CMD group were prevalent: 67 % hypertension, 44 % hyperlipidemia, and 33 % diabetes. Both CMD and RG had similar CAC score (25.86 ± 59.54 vs. 24.17 ± 104.6; p = 0.21. In the CMD group, 67 % had a CAC of 0. Minimal atherosclerosis (CAD-RADS 1) was present in 76 % of women with CMD. The CMD group had lower EAT attenuation than RG (-103.3 ± 6.33 HU vs. -97.9 ± 8.3 HU, p = 0.009, respectively). There were no differences in SCAT attenuation. Hypertension, smoking history, age, BMI, and CAC score did not correlate with EAT in either of the groups. CONCLUSIONS: Women with CMD have decreased EAT attenuation compared to RG women. EAT-mediated inflammation and changes in vascular tone may be a mechanistic contributor to abnormal microvascular reactivity. Clinical trials testing therapeutic strategies to decrease EAT may be warranted in the management of CMD.

Differential effect of atorvastatin and pravastatin on thoracic spine attenuation: A sub-analysis of a randomized clinical trial.

BACKGROUND: Statins reduce cardiovascular events and may improve bone mineral density. METHODS: We conducted a sub-analysis of a randomized clinical trial that investigated the differential effect of moderate vs intensive low-density lipoprotein cholesterol (LDL-C) lowering therapies on coronary artery calcium (CAC) scores, and used the acquired images to assess the change in radiological attenuation of selected thoracic vertebrae. Baseline and 12-month unenhanced chest CT scans were performed in 420 hyperlipidemic, postmenopausal women randomized to atorvastatin (ATV) 80 mg/day or pravastatin (PRV) 40 mg/day in the Beyond Endorsed Lipid Lowering with Electron Beam Tomography Scanning (BELLES) trial. Bone attenuation was measured in three contiguous thoracic vertebrae at baseline and 12 months. RESULTS: There were no differences in baseline demographic and clinical characteristics between treatment arms. The median percent lowering (interquartile range) in LDL-C was significantly greater with ATV than PRV [-53 (-69 to 20)% vs -28 (-55 to 74)%, p < 0.001], although the CAC score change was similar [12 (-63 to 208)% vs 13 (-75 to 358)%; p = 0.44]. At follow-up, the median bone attenuation loss was significantly greater with PRV than with ATV [-2.6 (-27 to 11)% vs 0 (-11 to 25)%; p < 0.001]. The attenuation loss in the PRV group was comparable to that of a historical untreated general population sample. In the entire cohort, the changes in LDL-C and total cholesterol were inversely correlated with bone attenuation change (p < 0.01). In adjusted multivariable linear regression analyses, race and percent change in LDL-C were independent predictors of bone attenuation change. Age, body mass index, history of smoking, diabetes mellitus, hypertension, peripheral vascular disease, or hormone replacement therapy did not affect percent change in BMD. CONCLUSIONS: These findings support the hypothesis that there is an interaction between bone and cardiometabolic health and that intensive lipid lowering has a beneficial effect on bone health.

Feasibility of Hepatic T1-Mapping and Extracellular Volume Quantification on Routine Cardiac Magnetic Resonance Imaging in Patients with Infiltrative and Systemic Disorders.

RATIONALE AND OBJECTIVES: Cardiac magnetic resonance imaging (CMR) is commonly obtained to evaluate for myocardial infiltrative disorders and fibrosis. Pre- and post-Gadolinium contrast T1-mapping sequences are employed to estimate interstitial expansion using extracellular volume fraction (ECV). Given the proximity of the liver to the heart, T1 and ECV quantification of the liver is feasible on CMR. The purpose of this study was to evaluate for hepatic measures of fibrosis and interstitial expansion in patients with amyloidosis or systemic disease on CMR. MATERIALS AND METHODS: Myocardial and hepatic native T1 values were measured retrospectively using a cardiac short axis modified Look-Locker inversion recovery sequence. Myocardial and hepatic ECV were calculated using pre- and post-contrast T1 and blood pool values according to the following formula: ECV = (Δ(1/T1) myocardium or liver and/or Δ(1/T1) blood)x(1 - hematocrit). Patients were divided into three cohorts by final diagnosis: amyloidosis, systemic disease (e.g. sarcoid, scleroderma), and controls (EF > 50, no ischemia). RESULTS: Of the 135 patients who underwent CMR, 22 had cardiac amyloidosis (age 59.9 ± 12.6 yrs, 41% female), 20 had systemic disease (age 50.9 ± 13.4 yrs, 35% female), and 93 were controls (age 49.5 ± 17.3 yrs, 50% female). Myocardial T1 and ECV values were highest for patients with amyloid, second highest for systemic disease, and least for controls (T1: 1169 ± 92 vs 1101 ± 53 vs 1027 ± 73 ms, p < 0.0001; ECV: 0.47 ± 0.11 vs 0.31 ± 0.05 vs 0.27 ± 0.04, p < 0.0001). Hepatic T1 and ECV were similarly higher in patients with amyloid and systemic disease compared to controls (T1: 646 ± 101 vs 660 ± 93 vs 595 ± 58 ms, p < 0.0001; ECV: 0.38 ± 0.08 vs 0.37 ± 0.05 vs 0.31 ± 0.03, p < 0.0001). There was a positive correlation between hepatic T1 and ECV (R2 = 0.282, p < 0.0001). No patients had abnormal liver function tests or clinical liver disease. CONCLUSION: Hepatic ECV quantification on CMR in patients with amyloidosis and systemic disorders is feasible. Further longitudinal investigation regarding detection of early or subclinical liver disease is warranted.

2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in Cardiovascular Imaging-Best Practices for Safety and Effectiveness, Part 2: Radiological Equipment Operation, Dose-Sparing Methodologies, Patient and Medical Personnel Protection.

The stimulus to create this document was the recognition that ionizing radiation-guided cardiovascular procedures are being performed with increasing frequency, leading to greater patient radiation exposure and, potentially, to greater exposure to clinical personnel. While the clinical benefit of these procedures is substantial, there is concern about the implications of medical radiation exposure. ACC leadership concluded that it is important to provide practitioners with an educational resource that assembles and interprets the current radiation knowledge base relevant to cardiovascular procedures. By applying this knowledge base, cardiovascular practitioners will be able to select procedures optimally, and minimize radiation exposure to patients and to clinical personnel. "Optimal Use of Ionizing Radiation in Cardiovascular Imaging - Best Practices for Safety and Effectiveness" is a comprehensive overview of ionizing radiation use in cardiovascular procedures and is published online. To provide the most value to our members, we divided the print version of this document into 2 focused parts. "Part I: Radiation Physics and Radiation Biology" addresses radiation physics, dosimetry and detrimental biologic effects. "Part II: Radiologic Equipment Operation, Dose-Sparing Methodologies, Patient and Medical Personnel Protection" covers the basics of operation and radiation delivery for the 3 cardiovascular imaging modalities (x-ray fluoroscopy, x-ray computed tomography, and nuclear scintigraphy). For each modality, it includes the determinants of radiation exposure and techniques to minimize exposure to both patients and to medical personnel.

2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in Cardiovascular Imaging-Best Practices for Safety and Effectiveness, Part 1: Radiation Physics and Radiation Biology: A Report of the American College of Cardiology Task Force on Expert Consensus Decision Pathways Developed in Collaboration With Mended Hearts.

The stimulus to create this document was the recognition that ionizing radiation-guided cardiovascular procedures are being performed with increasing frequency, leading to greater patient radiation exposure and, potentially, to greater exposure for clinical personnel. Although the clinical benefit of these procedures is substantial, there is concern about the implications of medical radiation exposure. The American College of Cardiology leadership concluded that it is important to provide practitioners with an educational resource that assembles and interprets the current radiation knowledge base relevant to cardiovascular procedures. By applying this knowledge base, cardiovascular practitioners will be able to select procedures optimally, and minimize radiation exposure to patients and to clinical personnel. Optimal Use of Ionizing Radiation in Cardiovascular Imaging: Best Practices for Safety and Effectiveness is a comprehensive overview of ionizing radiation use in cardiovascular procedures and is published online. To provide the most value to our members, we divided the print version of this document into 2 focused parts. Part I: Radiation Physics and Radiation Biology addresses the issue of medical radiation exposure, the basics of radiation physics and dosimetry, and the basics of radiation biology and radiation-induced adverse effects. Part II: Radiological Equipment Operation, Dose-Sparing Methodologies, Patient and Medical Personnel Protection covers the basics of operation and radiation delivery for the 3 cardiovascular imaging modalities (x-ray fluoroscopy, x-ray computed tomography, and nuclear scintigraphy) and will be published in the next issue of the Journal.

ACR Appropriateness Criteria® Chronic Chest Pain-High Probability of Coronary Artery Disease.

In patients with chronic chest pain in the setting of high probability of coronary artery disease (CAD), imaging has major and diverse roles. First, imaging is valuable in determining and documenting the presence, extent, and severity of myocardial ischemia, hibernation, scarring, and/or the presence, site, and severity of obstructive coronary lesions. Second, imaging findings are important in determining the course of management of patients with suspected chronic myocardial ischemia and better defining those patients best suited for medical therapy, angioplasty/stenting, or surgery. Third, imaging is also necessary to determine the long-term prognosis and likely benefit from various therapeutic options by evaluating ventricular function, diastolic relaxation, and end-systolic volume. Imaging studies are also required to demonstrate other abnormalities, such as congenital/acquired coronary anomalies and severe left ventricular hypertrophy, that can produce angina in the absence of symptomatic coronary obstructive disease due to atherosclerosis. Clinical risk assessment is necessary to determine the pretest probability of CAD. Multiple methods are available to categorize patients as low, medium, or high risk for developing CAD. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Rationale and design of the Randomized Evaluation of patients with Stable angina Comparing Utilization of noninvasive Examinations (RESCUE) trial.

RESCUE is a phase III, randomized, controlled, multicenter, comparative efficacy study, designed to compare two diagnostic imaging/treatment paradigms that use coronary computed tomography angiography (CCTA) or single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) for assisting in the diagnosis of ischemic heart disease in patients with stable angina symptoms, and guiding subsequent treatment. The study is based on the hypothesis that CCTA as a diagnostic tool is associated with no increase in cardiac risk, decreased cost, and reduced radiation exposure compared with SPECT MPI. The RESCUE trial was funded by the Agency for Healthcare Research and Quality (AHRQ) and the American College of Radiology Imaging Network (ACRIN) Fund for Imaging Innovation, began in 2011, and completed in 2014.

Mapping the future of cardiac MR imaging: case-based review of T1 and T2 mapping techniques.

Cardiac magnetic resonance (MR) imaging has grown over the past several decades into a validated, noninvasive diagnostic imaging tool with a pivotal role in cardiac morphologic and functional assessment and tissue characterization. With traditional cardiac MR imaging sequences, assessment of various pathologic conditions ranging from ischemic and nonischemic cardiomyopathy to cardiac involvement in systemic diseases (eg, amyloidosis and sarcoidosis) is possible; however, these sequences are most useful in focal myocardial disease, and image interpretation relies on subjective qualitative analysis of signal intensity. Newer T1 and T2 myocardial mapping techniques offer a quantitative assessment of the myocardium (by using T1 and T2 relaxation times), which can be helpful in focal disease, and demonstrate special utility in the evaluation of diffuse myocardial disease (eg, edema and fibrosis). Altered T1 and T2 relaxation times in disease states can be compared with published ranges of normal relaxation times in healthy patients. In conjunction with traditional cardiac MR imaging sequences, T1 and T2 mapping can limit the interpatient and interstudy variability that are common with qualitative analysis and may provide clinical markers for long-term follow-up.

Multimodality imaging of aortitis.

Multimodality imaging of aortitis is useful for identification of acute and chronic mural changes due to inflammation, edema, and fibrosis, as well as characterization of structural luminal changes including aneurysm and stenosis or occlusion. Identification of related complications such as dissection, hematoma, ulceration, rupture, and thrombosis is also important. Imaging is often vital for obtaining specific diagnoses (i.e., Takayasu arteritis) or is used adjunctively in atypical cases (i.e., giant cell arteritis). The extent of disease is established at baseline, with associated therapeutic and prognostic implications. Imaging of aortitis may be useful for screening, routine follow up, and evaluation of treatment response in certain clinical settings. Localization of disease activity and structural abnormality is useful for guiding biopsy or surgical revascularization or repair. In this review, we discuss the available imaging modalities for diagnosis and management of the spectrum of aortitis disorders that cardiovascular physicians should be familiar with for facilitating optimal patient care.

Adenosine stress magnetic resonance imaging in women with low risk chest pain: the Emory University experience.

OBJECTIVES: The purpose of this study was to evaluate the accuracy of adenosine stress magnetic resonance imaging (ASMRI) for the evaluation of women with low-risk chest pain (CP). BACKGROUND: Coronary artery disease (CAD) can present differently among women than among men. There is increased interest in the use of ASMRI for lower risk patients in the emergency department to rule out CAD, and it would be valuable to assess its performance specifically in women. METHODS: This study included 82 women with low-risk CP who presented to the emergency department during a 2-year period at our institution and were evaluated by ASMRI. Clinical events were followed by review of medical records. RESULTS: The specificity of ASMRI for ischemia detection in this small cohort of patients was 100%. Sensitivity was 94.9%, negative predictive value 100%, and positive predictive value 42.9%. CONCLUSIONS: ASMRI may be used as the initial imaging modality for ruling out CAD in women with low-risk CP because of its very high sensitivity, specificity, and negative predictive value for the detection of ischemia. Further randomized controlled trials comparing ASMRI with established noninvasive nuclear and echocardiographic stress modalities are needed.

Prognostic value of adenosine stress cardiovascular magnetic resonance in patients with low-risk chest pain.

BACKGROUND: Approximately 5% of patients with an acute coronary syndrome are discharged from the emergency room with an erroneous diagnosis of non-cardiac chest pain. Highly accurate non-invasive stress imaging is valuable for assessment of low-risk chest pain patients to prevent these errors. Adenosine stress cardiovascular magnetic resonance (AS-CMR) is an imaging modality with increasing application. The goal of this study was to evaluate the negative prognostic value of AS-CMR among low-risk acute chest pain patients. METHODS: We studied 103 patients, mean 56.7 + or - 12.3 years of age, with chest pain and no electrocardiographic evidence of ischemia and negative cardiac biomarkers of necrosis, who were admitted to the Cardiac Decision Unit of our institution. All patients underwent AS-CMR. A negative AS-CMR was defined as absence of all the following: regional wall motion abnormalities at rest; perfusion defects during stress (adenosine) and rest; and myocardial scar on late gadolinium enhancement images. The patients were followed for a mean of 277 (range 161-462) days. The primary end point was defined as the combination of cardiac death, nonfatal acute myocardial infarction, re-hospitalization for chest pain, obstructive coronary artery disease (>50% coronary stenosis on invasive angiography) and coronary revascularization. RESULTS: In 14 patients (13.6%), AS-CMR was positive. The remaining 89 patients (86.4%), who had negative AS-CMR, were discharged. No patient with negative AS-CMR reached the primary end-point during follow-up. The negative predictive value of AS-CMR was 100%. CONCLUSION: AS-CMR holds promise as a useful tool to rule out significant coronary artery disease in patients with low-risk chest pain. Patients with negative AS-CMR have an excellent short and mid-term prognosis.

Coronary artery calcium screening: current status and recommendations from the European Society of Cardiac Radiology and North American Society for Cardiovascular Imaging.

Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multidetector CT is discussed.

Coronary artery calcium screening: current status and recommendations from the European Society of Cardiac Radiology and North American Society for Cardiovascular Imaging.

Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multi-detector CT is discussed.

Calculation of coronary age using calcium scores in multiple ethnicities.

Coronary artery calcium (CAC) accumulation, a marker of atherosclerosis burden, differs significantly among patients of different ethnicities. It has been proposed that CAC scores can be used to assess the number of life years lost or gained by an individual with a given amount of coronary artery calcium. Therefore, we sought to develop a method to calculate the coronary age of an individual based on the extent of CAC in this subject compared to that of individuals of the same race, age and sex. We used median CAC scores from previously published data from the Multi-Ethnic Study of Atherosclerosis (MESA) to derive the predicted coronary age of subjects from 4 ethnic groups (White, Black, Hispanic and Chinese) of both sexes. With this method a 50-year-old white man with a CAC score of 40 has a coronary age of a 61-year-old white man; for a black man with a score of 40 the coronary age is 70. This method should allow patients to better understand the prognostic significance of their test results and may ensure a better compliance with preventive regimens.