Diagnostic performance of computed tomography angiography for differentiating ischemic vs nonischemic cardiomyopathy

The Role of Multimodality Imaging in Cardiomyopathy

PURPOSE OF REVIEW

There has been increasing use of multimodality imaging in the evaluation of cardiomyopathies.

RECENT FINDINGS

Echocardiography, cardiac magnetic resonance (CMR), cardiac nuclear imaging, and cardiac computed tomography (CCT) play an important role in the diagnosis, risk stratification, and management of patients with cardiomyopathies. Echocardiography is essential in the initial assessment of suspected cardiomyopathy, but a multimodality approach can improve diagnostics and management. CMR allows for accurate measurement of volumes and function, and can easily detect unique pathologic structures. In addition, contrast imaging and parametric mapping enable the characterization of tissue features such as scar, edema, infiltration, and deposition. In non-ischemic cardiomyopathies, metabolic and molecular nuclear imaging is used to diagnose rare but life-threatening conditions such amyloidosis and sarcoidosis. There is an expanding use of CCT for planning electrophysiology procedures such as cardioversion, ablations, and device placement. Furthermore, CCT can evaluate for complications associated with advanced heart failure therapies such as cardiac transplant and mechanical support devices. Innovations in multimodality cardiac imaging should lead to increased volumes and better outcomes.

An exemplary reanalysis of coronary computed tomography angiography diagnostic meta-analyses shows insufficient data sharing and incorrect sensitivity and specificity estimates

OBJECTIVES

To systematically evaluate the reproducibility of primary data and, the reproducibility and correctness of pooled sensitivity and specificity estimates reported in a sample of diagnostic meta-analyses.

STUDY DESIGN AND SETTING

We conducted an exemplary systematic review of diagnostic meta-analyses comparing coronary computed tomography angiography to invasive coronary angiography in patients with suspected coronary artery disease. The objectives were to assess 1) the reproducibility of contingency tables, 2) the reproducibility of pooled sensitivity and specificity, and 3) differences to reported results when applying a recommended bivariate binomial model for pooling sensitivity and specificity. Therefore, we reproduced the contingency tables and recalculated sensitivity and specificity by utilizing both the pooling method of each meta-analysis and a bivariate binomial model. We used linear trends to assess the improvement of these objectives over time.

RESULTS

We identified 38 diagnostic meta-analyses, each including on average 19 primary studies (range: 3 to 89 studies; total: 715-including duplicates) with an average of approximately 1800 patients per meta-analysis (range: 118 to 7516 patients). For 31 meta-analyses (82%, 95% CI: 65%, 91%), the contingency tables were reproducible; however, only 15 published them. Using the pooling method of each meta-analysis, we obtained comparable recalculated sensitivities/specificities for 28 meta-analyses (74% [57%, 86%]). Only 11 meta-analyses pooled sensitivity/specificity using a bivariate binomial model (29% [16%, 46%]). When all meta-analyses were pooled with this model, published sensitivities/specificities were confirmed for 19 of 38 meta-analyses (50% [34%, 66%]). There was only marginal improvement in data availability and application of recommended pooling methods over time.

CONCLUSION

Data sharing should become standard practice along with the use of appropriate pooling methods. Journal publication requirements may play a key role in enhancing the quality of scientific reporting and methodological standards which may lead to more reliable and consistent outcomes. The ability to reproduce sensitivity and specificity estimates in diagnostic imaging meta-analyses is dependent on the availability of contingency tables and the explicit reporting of pooling methods and software used.

Cardiac computed tomographic imaging in cardio-oncology: An expert consensus document of the Society of Cardiovascular Computed Tomography (SCCT). Endorsed by the International Cardio-Oncology Society (ICOS)

Cardio-Oncology is a rapidly growing sub-specialty of medicine, however, there is very limited guidance on the use of cardiac CT (CCT) in the care of Cardio-Oncology patients. In order to fill in the existing gaps, this Expert Consensus statement comprised of a multidisciplinary collaboration of experts in Cardiology, Radiology, Cardiovascular Multimodality Imaging, Cardio-Oncology, Oncology and Radiation Oncology aims to summarize current evidence for CCT applications in Cardio-Oncology and provide practice recommendations for clinicians.

Novel Cardiac Computed Tomography Methods for the Assessment of Anthracycline Induced Cardiotoxicity

Anthracyclines are among the most frequently utilized anti-cancer therapies; however, their use is frequently associated with off-target cardiotoxic effects. Cardiac computed tomography (CCT) is a validated and rapidly evolving technology for the evaluation of cardiac structures, coronary anatomy and plaque, cardiac function and preprocedural planning. However, with emerging new techniques, CCT is rapidly evolving to offer information beyond the evaluation of cardiac structure and epicardial coronary arteries to provide details on myocardial deformation, extracellular volume, and coronary vasoreactivity. The potential for molecular imaging in CCT is also growing. In the current manuscript we review these emerging computed tomography techniques and their potential role in the evaluation of anthracycline-induced cardiotoxicity.

Diagnostic accuracy of coronary computed tomography angiography in ischemic workup of heart failure: a meta-analysis

Aim: The role of coronary computed tomography angiography (CCTA) in evaluating the etiology of heart failure with reduced ejection fraction (HFrEF) is unclear. This is a meta-analysis assessing the pooled diagnostic accuracy of CCTA in diagnosing significant coronary artery disease in HFrEF. Materials & methods: Electronic databases were searched for studies comparing CCTA with invasive coronary angiography in HFrEF. A random-effects model meta-analysis was conducted. Results: Five studies comprising 269 patients were included. On patient-based analysis, pooled sensitivity and specificity of CCTA were 0.99 (95% CI: 0.94-1.00) and 0.94 (95% CI: 0.90-0.97), respectively. On segment-based analysis, pooled sensitivity and specificity were 0.74 (95% CI: 0.67-0.80) and 0.99 (95% CI: 0.98-0.99), respectively. Conclusion: CCTA has excellent diagnostic accuracy in diagnosing significant coronary artery disease in newly diagnosed HFrEF.

Multi-Modality Imaging in Dilated Cardiomyopathy: With a Focus on the Role of Cardiac Magnetic Resonance

Heart failure (HF) is recognized as a leading cause of morbidity and mortality worldwide. Dilated cardiomyopathy (DCM) is a common phenotype in patients presenting with HF. Timely diagnosis, appropriate identification of the underlying cause, individualized risk stratification, and prediction of clinical response to treatment have improved the prognosis of DCM over the last few decades. In this article, we reviewed the current evidence on available imaging techniques used for DCM patients. In this direction, we evaluated appropriate scenarios for the implementation of echocardiography, nuclear imaging, and cardiac computed tomography, and we focused on the primordial role that cardiac magnetic resonance (CMR) holds in the diagnosis, prognosis, and tailoring of therapeutic options in this population of special clinical interest. We explored the predictive value of CMR toward left ventricular reverse remodeling and prediction of sudden cardiac death, thus guiding the decisions for device therapy. Principles underpinning the use of state-of-the-art CMR techniques such as parametric mapping and feature-tracking strain analysis are also provided, along with expectations for the anticipated future advances in this field. We also attempted to correlate the evidence with clinical practice, with the intent to address questions on selecting the optimal imaging method for different indications and clinical needs. Overall, we recommend a comprehensive assessment of DCM patients at baseline and at follow-up intervals depending on the clinical status, with the addition of CMR as a second-line modality to other imaging techniques. We also provide an algorithm to guide the detailed imaging approach of the patient with DCM. We expect that future guidelines will upgrade their clinical recommendations for the utilization of CMR in DCM, which is expected to further improve the quality of care and the outcomes. This review provides an up-to-date perspective on the imaging of dilated cardiomyopathy patients and will be of clinical value to training doctors and physicians involved in the area of heart failure.

Computed Tomographic Angiography Assessment of Epicardial Coronary Vasoreactivity for Early Detection of Doxorubicin-Induced Cardiotoxicity

Background

The vascular endothelium is a novel target for the detection, management, and prevention of doxorubicin (DOX)-induced cardiotoxicity.

Objectives

The study aimed to: 1) develop a methodology by computed tomography angiography (CTA) to evaluate stress-induced changes in epicardial coronary diameter; and 2) apply this to a chronic canine model of DOX-induced cardiotoxicity to assess vascular toxicity.

Methods

To develop and validate quantitative methods, sequential retrospectively gated coronary CTAs were performed in 16 canines. Coronary diameters were measured at prespecified distances during rest, adenosine (ADE) (280 μg/kg/min), rest 30 min post-ADE, and dobutamine (DOB) (5 μg/kg/min). A subgroup of 8 canines received weekly intravenous DOX (1 mg/kg) for 12 to 15 weeks, followed by rest-stress CTA at cumulative doses of ∼4-mg/kg (3 to 5 mg/kg), ∼8-mg/kg (7 to 9 mg/kg), and ∼12-mg/kg (12 to 15 mg/kg) of DOX. Echocardiograms were performed at these timepoints to assess left ventricular ejection fraction and global longitudinal strain.

Results

Under normal conditions, epicardial coronary arteries reproducibly dilated in response to ADE (left anterior descending coronary artery [LAD]: 12 ± 2%, left circumflex coronary artery [LCx]: 13 ± 2%, right coronary artery [RCA]: 14 ± 2%) and DOB (LAD: 17 ± 3%, LCx: 18 ± 2%, RCA: 15 ± 3%). With DOX, ADE vasodilator responses were impaired after ∼4-mg/kg (LAD: –3 ± 1%, LCx: 0 ± 2%, RCA: –5 ± 2%) and ∼8-mg/kg (LAD: –3 ± 1%, LCx: 0 ± 1%, RCA: –2 ± 2%). The DOB dilation response was preserved at ∼4-mg/kg of DOX (LAD: 18 ± 4%, LCx: 11 ± 3%, RCA: 11 ± 2%) but tended to decrease at ∼8-mg/kg of DOX (LAD: 4 ± 2%, LCx: 8 ± 3%, RCA: 3 ± 2%). A significant left ventricular ejection fraction reduction was observed only at 12 to 15 mg/kg DOX (baseline: 63 ± 2%, 12-mg/kg: 45 ± 3%). Global longitudinal strain was abnormal at ∼4-mg/kg of DOX (p = 0.011).

Conclusions

CTA can reliably assess epicardial coronary diameter in response to pharmacological stressors, providing a noninvasive functional index of coronary vasoreactivity. Impaired epicardial vasodilation occurs early in DOX-induced cardiotoxicity.

Advanced Non-invasive Imaging Techniques in Chronic Heart Failure and Cardiomyopathies : Focus on Cardiac Magnetic Resonance Imaging and Computed Tomographic

Cardiomyopathies (Cs) are a heterogeneous group of myocardial diseases with structural and/or functional abnormalities.The aetiology is due to genetic-family substrate in most cases, however, the correct and detailed analysis of morphofunctional abnormalities (severity and distribution of hypertrophy, ventricular dilatation, ventricular dysfunction) and tissue characteristics (myocardial fibrosis, myocardial infiltration) are a crucial element for a definite diagnosis.Among the different diagnostic imaging modalities applied in clinical practice (echocardiography, nuclear medicine), cardiac magnetic resonance (CMR) has emerged as a non-invasive diagnostic tool having high ability to quantify systolic function and tissue abnormalities that represent the substrates of many Cs.The main added value of CMR is the ability to identify cardiomyopathies with respect to ischemic heart disease and, above all, to discriminate the major types of cardiomyopathies based on morpho-functional presentation patterns and the presence and location of myocardial fibrosis.Many CMR elements allow increasing diagnostic accuracy but CMR data should be integrated with an appropriate clinical and instrumental context.Computed Tomographic (CT) scan technology has showed a complementary role in patients having Cs and HF.In this chapter, the diagnostic, pathophysiologic and prognostic value of CMR and CT in heart failure due to the most common cardiomyopathies will be discussed.

Computed tomography of cardiomyopathies

Cardiac computed tomography (CT) is increasingly used in the evaluation of cardiomyopathies, particularly in patients who are not able to undergo other non-invasive imaging tests such as magnetic resonance imaging (MRI) due to the presence of MRI-incompatible pacemakers/defibrillators or other contraindications or due to extensive artifacts from indwelling metallic devices. Advances in scanner technology enable acquisition of CT images with high spatial resolution, good temporal resolution, wide field of view and multi-planar reconstruction capabilities. CT is useful in cardiomyopathies in several ways, particularly in the evaluation of coronary arteries, characterization of cardiomyopathy phenotype, quantification of cardiac volumes and function, treatment-planning, and post-treatment evaluation. In this article, we review the imaging techniques and specific applications of CT in the evaluation of cardiomyopathies.

Korean guidelines for the appropriate use of cardiac CT

The development of cardiac CT has provided a non-invasive alternative to echocardiography, exercise electrocardiogram, and invasive angiography and cardiac CT continues to develop at an exponential speed even now. The appropriate use of cardiac CT may lead to improvements in the medical performances of physicians and can reduce medical costs which eventually contribute to better public health. However, until now, there has been no guideline regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist clinicians and other health professionals in the use of cardiac CT for diagnosis and treatment of heart diseases, especially in patients at high risk or suspected of heart disease.

Assessment of the myocardium with cardiac computed tomography

The imaging of myocardial disease is of increasing importance for cardiologists from all subspecialties, for diagnosis, risk stratification, or to facilitate therapy. While the gold standard modalities for such assessment are cardiac magnetic resonance and echocardiography, these are not universally suitable. Cardiac computed tomography (CT), well-established for the assessment of coronary artery disease (CAD), can be of value in the assessment of myocardial pathology, due to excellent patient compatibility and tolerability, high spatial resolution, and acceptable tissue characterization. This review considers the value and limitations of CT in the assessment of the myocardial sequelae of CAD, and for patients with a variety of other cardiomyopathic diseases, depicts some of the common findings, and considers current developments in this area.

Coronary angiography is the gold standard for patients with significant left ventricular dysfunction

Left ventricular (LV) dysfunction has been shown to be significantly related to ongoing myocardial ischemia, hibernation, and thus, coronary artery disease. Current treatments for patients with LV dysfunction and concomitant coronary artery disease center around the potential benefit of coronary revascularization, in the form of either coronary artery bypass grafting surgery (CABG) or percutaneous coronary intervention (PCI). Given the great diversity in the patient population making up those with LV dysfunction and coronary artery disease, intense interest has been directed in determining which patients benefit the most from revascularization. Multiple noninvasive evaluations have been utilized in order to select or stratify these patients. However, the gold standard by which clinicians make revascularization determinations is invasive coronary angiography. Within this review, we compare and contrast the noninvasive modalities available to the present day clinician with invasive angiography. Furthermore, we outline the ways in which invasive angiography has been utilized in patients with LV dysfunction and summarize the present guidelines regarding its usefulness.