CT angiography with cardiac MRI: non-invasive functional and anatomical assessment for the etiology in newly diagnosed heart failure

Exclusion of ischemia is important in patients with newly diagnosed systolic heart failure (HF). We prospectively compared standard-of-care invasive catheter angiography (iCA) and echocardiography to a novel non-invasive strategy of both Coronary Computed Tomographic Angiography (CCTA) and Cardiovascular MRI (CMR) to determine the etiology of myocardial dysfunction Prospective data were collected from consecutive patients referred for iCA to investigate echocardiographically-confirmed new onset HF. CMR (1.5T GE) and dual source CCTA were performed within 2-7 days of iCA. Results were blinded and separately analyzed by expert readers. 426 coronary segments from 28 prospectively enrolled patients were analyzed by CCTA and quantitative iCA. The per-patient sensitivity and specificity of CCTA was 100% and 90%, respectively, negative predictive value (NPV) 100%, positive predictive value (PPV) 78%. Mean ejection fraction by CMR was 24%. Presence of ischemic-type LGE on CMR conferred a 67% sensitivity, 100% specificity, 90% NPV and 100% PPV. Combining CCTA with CMR conferred 100% specificity, 100% sensitivity, 100% PPV and 100% NPV for detection or exclusion of coronary disease. In patients with negative CCTA all invasive angiograms could have been avoided. In addition, two patients with no ischemic LGE by CMR had severe coronary disease on both CCTA and iCA, indicating global hibernation. This is a noteworthy finding in contrast to previous reports which suggested that absence of LGE rules out significant CAD. CCTA with CMR in newly-diagnosed HF enables non-invasive assessment of coronary artery disease, the severity and etiology of myocardial dysfunction and defines suitability for revascularization. Absence of ischemic-type LGE at CMR does not exclude CAD as a cause of LV dysfunction. A first-line strategy of functional and anatomic imaging with CMR and CCTA appears appropriate in newly diagnosed HF.     

Cardiac magnetic resonance simultaneously evaluates Leriche syndrome and prior inferior myocardial infarction

A woman with ECG findings suspicious of ischemic heart disease was referred for coronary angiography, but this was impossible via the left or right iliac arteries because of total occlusion. Cardiovascular magnetic resonance (CMR) was performed to assess the anatomy of the abdominal aorta, cardiac function, and myocardial viability in a single study. Contrast-enhanced magnetic resonance angiography (CE-MRA) revealed Leriche syndrome resulting from occlusion of the infrarenal aorta and common iliac arteries. Delayed contrast enhancement indicated full thickness nonviable myocardial infarction. Coronary angiography via the right radial artery revealed proximal occlusion of the right coronary artery. This is the first case that illustrates the value of CMR as a time-saving non-invasive imaging technique with the ability to do in a single study what might otherwise take two studies.     

The emerging role of cardiovascular magnetic resonance in the evaluation of Kawasaki disease

Kawasaki disease (KD) is a vasculitis affecting the coronary and systemic arteries. Myocardial inflammation is also a common finding in KD post-mortem evaluation during the acute phase of the disease. Coronary artery aneurysms (CAAs) develop in 15–25 % of untreated children. Although 50–70 % of CAAs resolve spontaneously 1–2 years after the onset of KD, the remaining unresolved CAAs can develop stenotic lesions at either their proximal or distal end and can develop thrombus formation leading to ischemia and/or infarction. Cardiovascular magnetic resonance (CMR) has the ability to perform non-invasive and radiation-free evaluation of the coronary artery lumen. Recently tissue characterization of the coronary vessel wall was provided by CMR. It can also image myocardial inflammation, ischemia and fibrosis. Therefore CMR offers important clinical information during the acute and chronic phase of KD. In the acute phase, it can identify myocardial inflammation, microvascular disease, myocardial infarction, deterioration of left ventricular function, changes of the coronary artery lumen and changes of the coronary artery vessel wall. During the chronic phase, CMR imaging might be of value for risk stratification and to guide treatment.     

Assessment of coronary artery disease with a combined magnetic resonance examination

Cardiovascular magnetic resonance (CMR) imaging provides morphological and functional data relevant to the assessment of coronary artery disease (CAD). A wide range of such data can be acquired in a single multiparametric imaging session. In stable CAD, a combined CMR examination comprising assessment of cardiac function, perfusion, and myocardial viability can be used to detect the presence of CAD and to determine the appropriateness of coronary revascularization. In acute coronary syndromes, a combined CMR examination can be used for the differential diagnosis of myocarditis and other acute cardiac disease, for risk-stratification of patients after myocardial infarction and for the targeted assessment of complications of myocardial infarction. This article overviews the CMR methods that are available for assessment of CAD and describes situations when combined CMR examinations can play a role in its diagnosis and differential diagnosis.     

Myocardial Assessment with Cardiac CT: Ischemic Heart Disease and Beyond

Purpose of Review

The aim of this review is to highlight recent advancements, current trends, and the expanding role for cardiac CT (CCT) in the evaluation of ischemic heart disease, nonischemic cardiomyopathies, and some specific congenital myocardial disease states.

Recent Findings

CCT is a highly versatile imaging modality for the assessment of numerous cardiovascular disease states. Coronary CT angiography (CCTA) is now a well-established first-line imaging modality for the exclusion of significant coronary artery disease (CAD); however, CCTA has modest positive predictive value and specificity for diagnosing obstructive CAD in addition to limited capability to evaluate myocardial tissue characteristics.

Summary

CTP, when combined with CCTA, presents the potential for full functional and anatomic assessment with a single modality. CCT is a useful adjunct in select patients to both TTE and CMR in the evaluation of ventricular volumes and systolic function. Newer applications, such as dynamic CTP and DECT, are promising diagnostic tools offering the possibility of more quantitative assessment of ischemia. The superior spatial resolution and volumetric acquisition of CCT has an important role in the diagnosis of other nonischemic causes of cardiomyopathies.

     

Myocardial Oxygenation Imaging: New Methods for Ischemia Detection

Myocardial ischemia is associated with many cardiovascular diseases, including coronary artery disease, congestive heart failure, hypertensive left ventricular hypertrophy, and diabetic cardiomyopathy, etc. The ischemia is caused by the imbalance of myocardial oxygen supply and demand. Positron emission tomography (PET) is the only noninvasive imaging technique to directly measure myocardial oxygenation. However, its low spatial resolution, limited availability, and ionizing radiation discourage the widespread use of PET to detect myocardial ischemia in clinical practice. The cardiac BOLD (blood-oxygen-level dependence) effect allows the measurement of myocardial oxygenation through T₂ or T₂* change using cardiac magnetic resonance (CMR) imaging techniques. Many efforts were made to improve the sensitivity of detecting this change and image quality for clinical evaluations. With relatively high spatial resolution, oxygenation in the subendocardium, a common location for myocardial ischemia, for the first time could be directly assessed by CMR oxygenation imaging. This method, combined with other CMR functional and anatomic imaging, will offer a one-stop shop for the detection of myocardial ischemia, even in the absence of angiographically significant coronary artery stenosis.     

The prominent role of cardiac magnetic resonance imaging in coronary artery disease

The role of cardiac magnetic resonance (CMR) in coronary artery disease is prominent. CMR provides functional and structural heart disease assessment with high accuracy. It allows accurate cardiac volume and flow quantification and wall motion analysis both at rest and at stress. CMR myocardial perfusion studies detect myocardial ischemia and provide insights into the morphology of the myocardial tissue. CMR imaging noninvasively differentiates causes of myocardial injury such as ischemia or inflammation; stages of myocardial injury, such as acute or chronic; grade of myocardial damage, such as reversible or irreversible; myocardial fibrosis or scar. There is an emerging role of CMR in patients with acute chest presentation since it can demonstrate causes of chest pain other than coronary artery disease such as myocarditis, pericarditis, aortic dissection and pulmonary embolism. CMR is noninvasive and radiation-free. It’s combined approach of functional and structural cardiac assessment makes it unique compared with other imaging modalities.     

MR and CT: When to Use Each

Coronary CT angiography (CCTA) and cardiovascular magnetic resonance (CMR) have evolved as quite useful techniques in chronic/acute coronary artery disease evaluation. The calcium score measurement quantifies coronary artery calcium and classifies the patients into low, intermediate, and high risk of major adverse coronary events. The CCTA value resides in the high accuracy to exclude the presence of coronary artery disease. CMR allows the acquisition of images throughout the body in any tomographic plane without limitations imposed by body habitus; also, it allows to characterize cardiovascular anatomy and structure, tissue composition, right and left ventricular function, and visualize and quantify myocardial perfusion along with viability. Since the acquisition is performed with cardiac gating in both methods, the left and right ventricular function can be calculated along with valvular characterization. Both techniques provide high-value anatomical/functional information that finally will impact on the patient’s treatment and survival.     

冠周脂肪衰减指数评估冠心病研究进展

冠状动脉周围脂肪组织(PCAT)为心外膜脂肪内的特殊脂肪组织，可通过旁分泌途径及直接刺激血管分泌多种抗炎及促炎因子，影响冠心病(CHD)发生、发展及心肌功能。衍生于冠状动脉CT血管成像(CCTA)的冠周脂肪衰减指数(FAI)是可无创量化冠状动脉炎症的影像学指标。本文就FAI的概念、影响因素及其在CHD中的应用进展进行综述。     

Staged cardiovascular magnetic resonance for differential diagnosis of Troponin T positive patients with low likelihood for acute coronary syndrome

Background

Cardiac Troponin-T (cTnT) is a cardio-specific indicator of myocardial necrosis due to ischemic or non-ischemic events. Considering the multiple causes of myocardial injury and treatment consequences there is great clinical need to clarify the underlying reason for cTnT release. We sought to implement acute CMR as a non-invasive imaging method for differential diagnosis of elevated cTnT in chest-pain unit (CPU) patients with non-conclusive symptoms and ECG-changes and a low to intermediate probability for coronary artery disease (CAD).

Results

CPU patients (n = 29) who had positive cTnT were scanned at 1.5T with a new step-by-step CMR algorithm including cine-, perfusion-, T2-, angiography-and late gadolinium enhancement (LGE) imaging. For comparison patients also underwent echocardiography and coronary angiography if necessary. CMR was conducted successfully in all patients and detected 93% of cTnT releases of unknown cause, without adverse hemodynamic or arrhythmic events. Acute myocardial infarction was detected in 11, pulmonary embolism in 6, myocarditis in 5, renal disease and cardiomyopathy in 2, storage disorder in 1 patient. In 2 patients CMR was unable to reveal the cause of cTnT elevations. Mean CMR scan-time was 35 ± 8 min. In 4 patients, CMR led to immediate coronary angiography with correct prediction of the infarct related artery.

Conclusions

We implemented a novel CMR algorithm to show the clinical value and practical feasibility of acute CMR in a non-conclusive patient cohort with unclear cTnT elevation. Since this pilot study has shown the feasibility of CMR in CPU patients, further prospective studies are warranted to compare CMR with other imaging modalities.     

Understanding physiology by using quantitative magnetic resonance perfusion imaging

Cardiac magnetic resonance (CMR) perfusion imaging enables precise quantitation of myocardial blood flow and has been validated in animal models. Myocardial perfusion imaging using a T1-sensitive imaging sequence during the first pass bolus injection of a gadolinium-based contrast agent remains the most robust and extensively studied to date. Myocardial blood flow could be calculated from signal intensity curves utilizing a tracer kinetic model or a model-independent deconvolution method. Quantitative CMR perfusion imaging has provided pathophysiologic insights in epicardial coronary artery disease, microvascular disease, and cardiomyopathy. Imaging at higher field strength, for both CMR first-pass perfusion and myocardial blood oxygen level-dependent imaging, is likely to advance quantitative myocardial perfusion in the future.     

心脏MRI评估心肌梗死病理变化的研究进展

心肌梗死是缺血性心脏病的重要临床特征,且其各阶段病理组织学改变均与患者预后密切相关。近年来,随着MRI软硬件技术的不断发展和完善,心脏MR （CMR）凭借多参数、多序列的成像技术特点,可定性、定量评估心肌梗死的相关病理变化,并可为患者的近期诊断及远期预后风险评估提供准确、全面的临床参考信息。本文就CMR在评估心肌梗死病理中的应用及研究进展进行综述。     

Novel Approaches to Myocardial Perfusion: 3D First-Pass CMR Perfusion Imaging and Oxygenation-Sensitive CMR

This article reviews technical aspects and the current status of novel cardiovascular magnetic resonance (CMR) approaches to assessing myocardial perfusion, specifically oxygenation-sensitive magnetic resonance imaging, comparing their diagnostic targets and clinical role with those of other imaging approaches. The paper includes discussions of relevant pathophysiological aspects of myocardial ischemia and the clinical context of revascularization in patients with suspected or known coronary artery disease. Research using oxygenation-sensitive CMR may play an important role for a better understanding of the interplay of coronary artery stenosis, blood flow reduction, and their impact on actual myocardial ischemia.     

Cardiac CT Improves Outcomes in Stable Coronary Heart Disease: Results of Recent Clinical Trials

Purpose of Review

The purpose of this study was to review the recent randomised controlled trials of coronary computed tomography angiography (CCTA) for patients with stable coronary artery disease.

Recent Findings

The initial results and subsequent papers from the SCOT-HEART (Scottish COmputed Tomography of the HEART) and PROMISE (PROspective Multicentre Imaging Study for Evaluation of chest pain) trials have shown that CCTA is a safe and appropriate addition to standard care or alternative to functional testing. The SCOT-HEART study showed that CCTA changes diagnoses, improves diagnostic certainty, changes management, leads to more appropriate use of invasive coronary angiography, and reduces fatal and non-fatal myocardial infarction. A meta-analysis of the four randomised controlled trials showed that CCTA leads to a major reduction in myocardial infarction in patients with stable chest pain.

Summary

CCTA is now an established technique for the assessment of coronary artery disease. Recent ‘test and treat’ randomised controlled trials have shown that CCTA guided changes in management can improve clinical outcomes.

     

Cardiovascular magnetic resonance findings in repaired anomalous left coronary artery to pulmonary artery connection (ALCAPA)

Background

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare coronary artery anomaly. This study shows the role of cardiovascular magnetic resonance (CMR) in assessing young patients following surgical repair of ALCAPA.

Methods

6 patients, aged 9-21 years, with repaired ALCAPA (2 Tackeuchi method, 4 direct re-implantation) underwent CMR because of clinical suspicion of myocardial ischemia. Imaging used short and long axis cine images (assess ventricular function), late-gadolinium enhancement (LGE) (detect segmental myocardial fibrosis), adenosine stress perfusion (detect reversible ischaemia) and 3D whole-heart imaging (visualize proximal coronary arteries).

Results

The left ventricular (LV) global systolic function was preserved in all patients (mean LV ejection fraction = 62.7% ± 4.23%). The LV volumes were within the normal ranges, (mean indexed LVEDV = 75.4 ± 3.5 ml/m², LVESV = 31.6 ± 9.4 ml/m²). In 1 patient, hypokinesia of the anterior segments was visualized. Five patients showed sub-endocardial LGE involving the basal, antero-lateral wall and the anterior papillary muscle. Three patients had areas of reversible ischemia. In these 3, 3D whole-heart MRA showed that the proximal course of the left coronary artery was occluded (confirmed with cardiac catheterisation).

Conclusions

CMR is a good, non-invasive, radiation-free investigation in the post-surgical evaluation of ALCAPA. In referred patients we show that basal, antero-lateral sub-endocardial myocardial fibrosis is a characteristic finding. Furthermore, stress adenosine CMR perfusion, can identify reversible ischemia in this group, and was indicative of left coronary artery occlusion.     

Value of black blood T2* cardiovascular magnetic resonance

Background

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare coronary artery anomaly. This study shows the role of cardiovascular magnetic resonance (CMR) in assessing young patients following surgical repair of ALCAPA.

Methods

6 patients, aged 9-21 years, with repaired ALCAPA (2 Tackeuchi method, 4 direct re-implantation) underwent CMR because of clinical suspicion of myocardial ischemia. Imaging used short and long axis cine images (assess ventricular function), late-gadolinium enhancement (LGE) (detect segmental myocardial fibrosis), adenosine stress perfusion (detect reversible ischaemia) and 3D whole-heart imaging (visualize proximal coronary arteries).

Results

The left ventricular (LV) global systolic function was preserved in all patients (mean LV ejection fraction = 62.7% ± 4.23%). The LV volumes were within the normal ranges, (mean indexed LVEDV = 75.4 ± 3.5 ml/m², LVESV = 31.6 ± 9.4 ml/m²). In 1 patient, hypokinesia of the anterior segments was visualized. Five patients showed sub-endocardial LGE involving the basal, antero-lateral wall and the anterior papillary muscle. Three patients had areas of reversible ischemia. In these 3, 3D whole-heart MRA showed that the proximal course of the left coronary artery was occluded (confirmed with cardiac catheterisation).

Conclusions

CMR is a good, non-invasive, radiation-free investigation in the post-surgical evaluation of ALCAPA. In referred patients we show that basal, antero-lateral sub-endocardial myocardial fibrosis is a characteristic finding. Furthermore, stress adenosine CMR perfusion, can identify reversible ischemia in this group, and was indicative of left coronary artery occlusion.     

BOLD cardiovascular magnetic resonance at 3.0 tesla in myocardial ischemia

Background

The purpose of this study was to determine the ability of Blood Oxygen Level Dependent (BOLD) cardiovascular magnetic resonance (CMR) to detect stress-inducible myocardial ischemic reactions in the presence of angiographically significant coronary artery disease (CAD).

Methods

Forty-six patients (34 men; age 65 ± 9 years,) with suspected or known coronary artery disease underwent CMR at 3Tesla prior to clinically indicated invasive coronary angiography. BOLD CMR was performed in 3 short axis slices of the heart at rest and during adenosine stress (140 μg/kg/min) followed by late gadolinium enhancement (LGE) imaging. In all 16 standard myocardial segments, T2* values were derived at rest and under adenosine stress. Quantitative coronary angiography served as the standard of reference and defined normal myocardial segments (i.e. all 16 segments in patients without any CAD), ischemic segments (i.e. supplied by a coronary artery with ≥50% luminal narrowing) and non-ischemic segments (i.e. supplied by a non-significantly stenosed coronary artery in patients with significant CAD).

Results

Coronary angiography demonstrated significant CAD in 23 patients. BOLD CMR at rest revealed significantly lower T2* values for ischemic segments (26.7 ± 11.6 ms) compared to normal (31.9 ± 11.9 ms; p < 0.0001) and non-ischemic segments (31.2 ± 12.2 ms; p = 0.0003). Under adenosine stress T2* values increased significantly in normal segments only (37.2 ± 14.7 ms; p < 0.0001).

Conclusions

Rest and stress BOLD CMR at 3Tesla proved feasible and differentiated between ischemic, non-ischemic, and normal myocardial segments in a clinical patient population. BOLD CMR during vasodilator stress identified patients with significant CAD.     

Extracorporeal cardiac shock wave therapy for angina pectoris

Prognosis of severe ischemic heart disease with no indication of percutaneous coronary intervention or coronary artery bypass grafting remains poor. Extracorporeal shock wave (SW) therapy was introduced for medical therapy more than 20 years ago to break up kidney stones. We have demonstrated that extracorporeal cardiac SW therapy at a low level (about 10% of the energy density that used for urinary lithotripsy), effectively induces coronary angiogenesis and improves myocardial ischemia in a porcine model of chronic myocardial ischemia in vivo. Also, our extracorporeal cardiac SW therapy improved symptoms and myocardial ischemia in patients with severe coronary artery disease. Importantly, no procedural complications or adverse effects were noted. These results indicate that our extracorporeal cardiac SW therapy is an effective and non-invasive treatment for ischemic heart disease.     

冠状动脉CT血管造影影像组学用于冠心病研究进展

冠状动脉CT血管造影(CCTA)是无创评估冠心病(CAD)及预测其风险分层的一线检查方法,对于识别冠状动脉斑块、评估血管周围脂肪组织、识别心肌缺血等具有重要临床价值。影像组学可提取高通量医学图像定量特征,具有广阔应用前景。本文对CCTA影像组学用于CAD研究进展进行综述。     

Echocardiography and coronary artery disease: Current and future applications

Echocardiographic techniques are becoming more widespread for evaluating patients with known or suspected coronary artery disease. Because it affords an excellent overall view of the heart, two-dimensional echocardiography, rather than M-mode echocardiography, is the imaging procedure of choice when dealing with coronary artery disease. This technique can be used to make the initial diagnosis of acute myocardial infarction, diagnose complications, and assess prognosis following myocardial infarction. Additionally by combining this test with stress testing, latent coronary artery disease can be detected. Recovery of wall motion can be assessed following interventions such as thrombolysis or balloon angioplasty. Investigational and future uses include tissue characterization, which may allow detection of ischemic but potentially viable myocardium, direct coronary visualization for detection of atherosclerotic involvement of the proximal coronary arteries and myocardial contrast echocardiography. The latter technique allows visualization of perfusion by way of injecting contrast material into the coronary circulation. This has been demonstrated to be an accurate means of determining myocardial infarction size in an animal model and is currently being used in a number of centers in patients at the time of cardiac catheterization. In summary two-dimensional echocardiography currently allows assessment of patients with myocardial infarction from the time of their presentation through their convalescent period with respect to diagnosis, prognosis and presence of complications. Exercise echocardiography can diagnose latent coronary artery disease. The newer investigational techniques show promise for furthering our ability to evaluate patients with coronary artery disease using echocardiography.