The usefulness of delayed enhancement magnetic resonance imaging for diagnosis and evaluation of cardiac function in patients with cardiac sarcoidosis

Role of 3 Tesla Magnetic Resonance Imaging in the Assessment of Infiltrative Cardiomyopathies

BACKGROUND

The aim of the present study was to assess the role of 3 Tesla (3T) magnetic resonance imaging (MRI) in the assessment of infiltrative cardiomyopathy (ICM).

METHODS

Cardiac MRI was performed on a 3T MRI machine for 15 patients who had clinical or echocardiographic signs of infiltrative cardiomyopathy. Each scan was assessed on a set of anatomical and functional parameters. The patterns of left ventricular (LV) late gadolinium enhancement (LGE) were also analyzed.

RESULTS

Bi-atrial dilatation was noted in 14 patients, consistent with a restrictive phenotype. All 15 patients had diastolic dysfunction with reduced LV diastolic ventricular filling and prolonged peak filling times. Eleven patients had a decreased peak filling rate. Twelve patients had systolic dysfunction with reduced ejection fraction (EF). Ten patients had contractile dysfunction in the form of global LV hypokinesia. On delayed contrast imaging, four patients showed no abnormal LGE. Two patients showed diffuse subendocardial enhancement. Two patients showed patchy subendocardial enhancement. Six patients showed patchy mid-myocardial enhancement. One patient showed diffuse mid-myocardial enhancement. Three patients showed patchy subepicardial enhancement. Two patients showed patchy transmural enhancement. Three patients showed reversed myocardial nulling. All 15 patients received a provisional diagnosis of infiltrative cardiomyopathy on the basis of cardiac MRI findings. Sarcoidosis was given as a probable cause in four patients, amyloidosis in three patients, an infectious cause in two patients, and drug-induced cardiomyopathy in one patient. In five patients, no obvious cause could be identified.

CONCLUSION

Infiltrative cardiomyopathies, although relatively uncommon, pose significant challenges in diagnosis and treatment. Cardiac MRI has become the gold standard for non-invasive diagnosis of all infiltrative cardiomyopathies.

The Role of Multimodality Imaging in Cardiac Sarcoidosis

The etiology and the progression of sarcoidosis remain unknown. However, cardiac sarcoidosis (CS) is significantly associated with a poor prognosis due to the associated congestive heart failure, arrhythmias (such as an advanced atrioventricular block), and ventricular tachyarrhythmia. Novel imaging modalities are now available to detect CS lesions secondary to active inflammation, granuloma formation, and fibrotic changes. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and cardiac magnetic resonance imaging (CMR) play essential roles in diagnosing and monitoring patients with confirmed or suspected CS. The following focused review will highlight the emerging role of non-invasive cardiac imaging techniques, including FDG PET/CT and CMR.

Utility of FDG PET and Cardiac MRI in Diagnosis and Monitoring of Immunosuppressive Treatment in Cardiac Sarcoidosis

PURPOSE

To compare the contributions of cardiac MRI and PET in the diagnosis and management of cardiac sarcoidosis (CS), with particular reference to quantitative measures.

MATERIALS AND METHODS

This is a retrospective, observational study of 31 patients (mean age, 45.7 years) with proven extracardiac sarcoidosis and possible CS who were investigated with fluorine 18 fluorodeoxyglucose (FDG) PET/CT and cardiac MRI. Patients were treated at physicians' discretion with repeat combined imaging after an interval of 102-770 days (median, 228 days).

RESULTS

Significant myocardial FDG uptake was shown on visit 1 (myocardial maximum standardized uptake value [SUVmax] > 3.6) in 17 of 22 patients who were subsequently treated. Myocardial SUVmax decreased at follow-up (6.5 to 4.0; P < .01) and was matched by significant decreases in FDG-avid lung and mediastinal node disease. A volumetric measure of myocardium above a threshold SUV (cardiac metabolic volume) decreased from a mean of 42.5 to a mean of 4.1 (P < .001). This was associated with significant improvement in the left ventricular ejection fraction (LVEF) (45.8 increasing to 50.9; P < .031). There was no change in volume of late gadolinium enhancement at treatment. Patients who were untreated showed no change in any FDG PET or cardiac MRI parameter.

CONCLUSION

Myocardial FDG uptake in patients suspected of having CS is presumed to represent active inflammation. When treated with corticosteroids, this resolved or regressed at follow-up, with an improvement in LVEF and FDG-avid thoracic disease. Patients who were untreated showed no change in any parameter. Quantification of FDG-avid myocardium using cardiac metabolic volume is proposed as a useful objective measure for assessing response to therapy.© RSNA, 2020See also commentary by Gutberlet in this issue.

Diagnostic accuracy of cardiac MRI, FDG-PET, and myocardial biopsy for the diagnosis of cardiac sarcoidosis: a protocol for a systematic review and meta-analysis

BACKGROUND

CS constitutes a rare but potentially underdiagnosed and fatal disease. Its diagnosis remains difficult owing to the infrequent and indistinguishable symptoms and the lack of formal diagnostic criteria dependent upon the diagnostic techniques used. Early diagnosis and treatment, however, may help to counter its poor prognosis.We aim to characterize and compare the diagnostic accuracy of cardiac MRI, FDG-PET and myocardial biopsy for the diagnosis of cardiac sarcoidosis and to advance and compare methods for complex diagnostic test accuracy reviews and meta-analysis.

METHODS

Following a systematic review on DTA studies on the aforementioned topic, a four-part approach to meta-analysis will be used: (1) direct comparison of index tests with clinical reference standard, (2) indirect comparison of index tests with clinical reference standard, (3) addition of an alternative test to that indirect comparison (4) and Bayesian meta-analysis using results of part 3 as informative prior for comparisons analogous to part 1 and 2.

DISCUSSION

The most widely recognized diagnostic algorithm for cardiac sarcoidosis is considered out of date, as it precedes the introduction of imaging techniques in diagnostic pathways. These novel imaging techniques, like CMR and FDG-PET scan, have emerged as promising diagnostic tools which may fill the current diagnostic gap. Thus, a systematic review and evaluation of CS diagnosis are much needed. Such an attempt is anticipated to alter the current diagnostic guidelines for CS by shedding more light on the role of sophisticated imaging techniques on prompt CS therapy and follow-up.

TRIAL REGISTRATION

PROSPERO, CRD42019047126.

Discrepancy between significant fibrosis and active inflammation in patients with cardiac sarcoidosis: combined and image fusion analysis of cardiac magnetic resonance and 18F fluorodeoxyglucose positron emission tomography

Background

Diagnosis and evaluation of cardiac sarcoidosis (CS) are mainly based on the combined use of cardiac magnetic resonance imaging (CMR) and ¹⁸F fludeoxyglucose positron emission tomography (FDG). Though these modalities can detect the pathological feature of the disease, combined assessment has not been fully examined. Multimodality image fusion is known to be useful for further comprehension, while most image interpretation is performed with a side by side comparison in clinical routine. We investigated the similarity and discrepancy of active inflammation, regional fibrosis, and wall function by image fusion of CMR and FDG.

Methods

Patients with CS who underwent both CMR and FDG were retrospectively enrolled. The extent of myocardial late gadolinium enhancement (LGE) in left ventricle (LGE volume), cardiac function, and volume (left ventricular ejection fraction, LVEF; end-diastolic volume, EDV) was measured from CMR. The FDG uptake in whole myocardium (whole SUVmax), cardiac metabolic volume (CMV), and cardiac metabolic activity (CMA) was calculated from FDG. CMR and FDG were fused and divided into AHA 17 model for segmental analysis. Wall motion, the magnitude of LGE in myocardial wall (LGE%wall), and corresponding FDG uptake (segmental SUVmax) were analyzed.

Results

Forty-one patients were retrospectively enrolled. In patients with FDG uptake, LVEF inversely correlated to LGE volume and positively correlated to SUVmax (r = − 0.56, p < 0.0001, and r = 0.08, p = 0.048, respectively). Discrepancy between LGE volume and CMV showed a significant positive correlation to whole SUVmax and CMA (r = 0.49, p < 0.0001, and r = 0.96, p < 0.0001, respectively). In image fusion analysis, segmental SUVmax showed a significant inverse correlation to LGE%wall (Spearman’s rank correlation coefficient; r = − 0.15, p = 0.008). LGE%wall also showed significant inverse correlation to wall motion (r = − 0.13, p = 0.0011).

Conclusion

Combined and fusion analysis with CMR and FDG demonstrated the discrepancy of myocardial inflammation and extensive fibrosis. Active inflammation was present in the earlier stage of myocardial fibrosis and was found to be less in the wall with advanced fibrosis and remodeling. Combined analysis of CMR and FDG can incrementally reclassify the pathological stage of CS.

Cardiac magnetic resonance imaging-indeterminate/negative cardiac sarcoidosis revealed by 18F-fluorodeoxyglucose-positron emission tomography: two case reports and a review of the literature

Background

Sarcoidosis is an inflammatory disorder of immune dysregulation characterized by non-caseating granulomas that can affect any organ. Cardiac sarcoidosis is an under-recognized entity that has a heterogeneous presentation and may occur independently or with any severity of systemic disease. Diagnosing cardiac sarcoidosis remains problematic with endomyocardial biopsies associated with a high risk of complications. Several diagnostic algorithms are currently available that rely on histopathology or clinical and radiological measures. The dominant mode of diagnostic imaging to date for cardiac sarcoidosis has been cardiac magnetic resonance imaging with gadolinium enhancement.

Case presentations

We report the cases of two adult patients: case 1, a 50-year-old white man who presented with severe congestive cardiac failure; and case 2, a 37-year-old white woman who presented with complete heart block. Both patients had a background of untreated pulmonary sarcoidosis. Cardiac magnetic resonance imaging did not show evidence of sarcoidosis in either patient and both proceeded to ¹⁸F-fluorodeoxyglucose-positron emission tomography scans that were highly suggestive of cardiac sarcoidosis. Both patients were systemically immunosuppressed with orally administered prednisone and methotrexate and had subsequent improvement by clinical and nuclear medicine imaging measures.

Conclusions

Current consensus guidelines recommend all patients with sarcoidosis undergo screening for occult cardiac disease, with thorough history and examination, electrocardiogram, and transthoracic echocardiogram. If any abnormalities are detected, advanced cardiac imaging should follow. While cardiac magnetic resonance imaging identifies the majority of cardiac sarcoidosis, early disease may not be detected. These cases demonstrate ¹⁸F-fluorodeoxyglucose-positron emission tomography is warranted following an indeterminate or normal cardiac magnetic resonance imaging if clinical suspicion remains high. Unidentified and untreated cardiac sarcoidosis risks significant morbidity and mortality, but early detection can facilitate disease-modifying immunosuppression and cardiac-specific interventions.

Nonrigid registration with corresponding points constraint for automatic segmentation of cardiac DSCT images

Background

Dual-source computed tomography (DSCT) is a very effective way for diagnosis and treatment of heart disease. The quantitative information of spatiotemporal DSCT images can be important for the evaluation of cardiac function. To avoid the shortcoming of manual delineation, it is imperative to develop an automatic segmentation technique for 4D cardiac images.

Methods

In this paper, we implement the heart segmentation-propagation framework based on nonrigid registration. The corresponding points of anatomical substructures are extracted by using the extension of n-dimensional scale invariant feature transform method. They are considered as a constraint term of nonrigid registration using the free-form deformation, in order to restrain the large variations and boundary ambiguity between subjects.

Results

We validate our method on 15 patients at ten time phases. Atlases are constructed by the training dataset from ten patients. On the remaining data the median overlap is shown to improve significantly compared to original mutual information, in particular from 0.4703 to 0.5015 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ p = 5.0 \times 10^{ - 4} $$\end{document}p=5.0×10-4) for left ventricle myocardium and from 0.6307 to 0.6519 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ p = 6.0 \times 10^{ - 4} $$\end{document}p=6.0×10-4) for right atrium.

Conclusions

The proposed method outperforms standard mutual information of intensity only. The segmentation errors had been significantly reduced at the left ventricle myocardium and the right atrium. The mean surface distance of using our framework is around 1.73 mm for the whole heart.

Magnetic resonance imaging of cardiac sarcoidosis: an evaluation of the cardiac segments and layers that exhibit late gadolinium enhancement

Cardiac sarcoidosis (CS) can cause sudden death, which is the leading cause of mortality in patients with sarcoidosis in Japan. However, it is difficult to diagnose CS because of the lack of a sensitive diagnostic method for the condition. Late gadolinium-enhanced cardiac magnetic resonance (MR) imaging demonstrates improved sensitivity for diagnosing CS. Therefore, it is important to know the late gadolinium-enhancement (LGE) characteristics of CS on cardiac MR images in order to diagnose CS accurately. In this study, we investigated the most common sites of LGE on cardiac MR images in CS. Late gadolinium-enhanced MR images of 9 consecutive patients with CS (obtained between August 2009 and July 2015) were reviewed by two radiologists. The distribution of LGE was evaluated using the American Heart Association 17-segment model of the left ventricle. The LGE in each segment was also classified into 4 patterns according to the myocardial layer in which it occurred (the subepicardial, subendocardial, intramural, and transmural layer patterns). All 9 patients exhibited LGE in their left ventricle, and 70 of 153 (46%) myocardial segments were enhanced. All of the patients displayed LGE in the basal septal wall. The patients' LGE layer patterns were as follows: subepicardial: 40% (28/70), intramural: 30% (21/70), subendocardial: 16% (11/70), and transmural: 14% (10/70). The basal septum wall and subepicardial layer often exhibit LGE on cardiac MR images in CS patients. LGE can be observed in other segments and layers in some cases.

Intra-cardiac distribution of late gadolinium enhancement in cardiac sarcoidosis and dilated cardiomyopathy

Cardiac involvement of sarcoid lesions is diagnosed by myocardial biopsy which is frequently false-negative, and patients with cardiac sarcoidosis (CS) who have impaired left ventricular (LV) systolic function are sometimes diagnosed with dilated cardiomyopathy (DCM). Late gadolinium enhancement (LE) in magnetic resonance imaging is now a critical finding in diagnosing CS, and the novel Japanese guideline considers myocardial LE to be a major criterion of CS. This article describes the value of LE in patients with CS who have impaired LV systolic function, particularly the diagnostic and clinical significance of LE distribution in comparison with DCM. LE existed at all LV segments and myocardial layers in patients with CS, whereas it was localized predominantly in the midwall of basal to mid septum in those with DCM. Transmural (nodular), circumferential, and subepicardial and subendocardial LE distribution were highly specific in patients with CS, whereas the prevalence of striated midwall LE were high both in patients with CS and with DCM. Since sarcoidosis patients with LE have higher incidences of heart failure symptoms, ventricular tachyarrhythmia and sudden cardiac death, the analyses of extent and distribution of LE are crucial in early diagnosis and therapeutic approach for patients with CS.

Prevalence of cardiac sarcoidosis in white population: a case-control study: Proposal for a novel risk index based on commonly available tests

Cardiac sarcoidosis (CS) is a life-threatening and underdiagnosed manifestation of the disease, which requires a complicated and expensive diagnostic pathway. There is a need for simple tool for practitioners to determine the risk of CS without access to specialized equipment.The aim of study was to determine the prevalence of CS in a group of patients diagnosed with or followed up because of sarcoidosis. A secondary objective was the search for factors associated with heart involvement.We performed a prospective case-control study (screening analysis) in consecutive sarcoidosis patients collected from October 2012 to September 2015. Cardiac magnetic resonance (CMR) imaging was performed to confirm or exclude cardiac involvement in all patients. The study was conducted in a hospital-based referral center for patients with sarcoidosis and other interstitial lung diseases.Analysis was performed in a group of 201 patients (all white) with biopsy-proven sarcoidosis, mean age 41.4 ± 10.2, 121 of them (60.2%) males. Four patients with previously recognized cardiac diseases, which make CMR imaging for CS inconclusive, were not included.Cardiac involvement was detected by CMR in 49 patients (24.4%). Factors associated with an increased risk of CS (univariate analyses) included male sex (odds ratio [OR]: 2.5; 1.21-5.16, P = 0.01), cardiac-related symptoms (OR: 3.53; 1.81-6.89, P = 0.0002), extrathoracic sarcoidosis (OR: 3.48; 1.77-6.84, P = 0.0003), elevated serum NT-proBNP (OR: 3.82; 1.55-9.42, P = 0.004), any electrocardiography abnormality (OR: 5.38; 2.48-11.67, P = 0.0001), and contemporary radiological progression sarcoidosis in the lungs (OR: 2.98; 1.52-5.84, P = 0.001). Abnormalities in echocardiography and Holter ECG were also risk factors, but not significant in multivariate analyses. A CS Risk Index was developed using a multivariate model to predict CS, achieving an accuracy of 82%, sensitivity of 50%, specificity of 94%, and likelihood ratio 8.1.CS was detected in one fourth of patients. A CS Risk Index based on the results of easily accessible tests is cost-effective and may help to identify patients who should be urgently referred for further diagnostic procedures.

High mass (>18g) of late gadolinium enhancement on CMR imaging is associated with major cardiac events on long-term outcome in patients with biopsy-proven extracardiac sarcoidosis

BACKGROUND

Cardiac involvement is the most important cause of mortality in patients with systemic sarcoidosis. Late gadolinium enhancement (LGE) on cardiovascular magnetic resonance imaging (CMR) has been shown to be a predictor of major cardiovascular adverse events (MACE) in the setting of systemic sarcoidosis. We sought to evaluate the relationship between LGE mass and adverse long-term outcome in patients with biopsy-proven extracardiac sarcoidosis.

METHODS

Between 2001 and 2013, 197 consecutive patients with suspected cardiac sarcoidosis were identified in our institution database. Of them, 56 patients have had biopsy-proven extracardiac sarcoidosis and represented our studied population. Patients were divided into two groups based on LGE mass by a median value (mild LGE<18g, high LGE>18g) for comparison of MACE.

RESULTS

Twenty-eight patients had a high mass of LGE. Of them, 15 (54%) experienced MACE (OR=31.15, 95% CI 3.7-262). Except for 1 patient, no patient with mild LGE presented with any MACE during follow-up (median of 32months). Patients with high LGE had lower CMR-derived left (53.6±14.9 vs. 62.2±6.7, p<0.01) and right (49.1±11.5 vs. 56.4±9.2, p<0.05) ventricular ejection fractions. LGE mass of 18g discriminated patients with and without MACE (93% sensitivity, 88% specificity, AUC=0.972). LGE mass was the only independent predictor of MACE on multivariate Cox analysis adjusted (OR=1.7, 95% CI 1.06 to 2.72, p=0.03).

CONCLUSION

In biopsy-proven extracardiac sarcoidosis patients, a high mass of LGE >18g was associated with MACE.

Biomarkers in sarcoidosis

INTRODUCTION

Numerous biomarkers have been evaluated for the diagnosis, assessment of disease activity, prognosis, and response to treatment in sarcoidosis. In this report, we discuss the clinical and research utility of several biomarkers used to evaluate sarcoidosis. Areas covered: The sarcoidosis biomarkers discussed include serologic tests, imaging studies, identification of inflammatory cells and genetic analyses. Literature was obtained from medical databases including PubMed and Web of Science. Expert commentary: Most of the biomarkers examined in sarcoidosis are not adequately specific or sensitive to be used in isolation to make clinical decisions. However, several sarcoidosis biomarkers have an important role in the clinical management of sarcoidosis when they are coupled with clinical data including the results of other biomarkers.

Pathophysiology and clinical management of cardiac sarcoidosis

Cardiac sarcoidosis is a potentially life-threatening condition characterized by formation of granulomas in the heart, resulting in conduction disturbances, atrial and ventricular arrhythmias, and ventricular dysfunction. The presentation of cardiac sarcoidosis ranges from asymptomatic with an abnormal imaging scan, to palpitations, syncope, symptoms of congestive heart failure, and sudden cardiac death. Screening for cardiac sarcoidosis has not been standardized, but the presence of cardiac symptoms on medical history and physical examination, and an abnormal electrocardiogram (ECG), Holter monitoring, or echocardiogram has been shown to be highly sensitive for detecting cardiac sarcoidosis. A signal-averaged ECG might also have a role in screening for cardiac sarcoidosis in asymptomatic patients. Although endomyocardial biopsies are highly specific for the diagnosis of cardiac sarcoidosis, procedural yield is very low and appropriate findings on cardiac MRI or PET are, therefore, often used as diagnostic surrogates. Treatment for cardiac sarcoidosis usually involves immunosuppressive therapy, particularly corticosteroids. Additional therapy might be required, depending on the clinical presentation, including implantation of an internal defibrillator, antiarrhythmic agents, and catheter ablation.

Distribution of late gadolinium enhancement in various types of cardiomyopathies: Significance in differential diagnosis, clinical features and prognosis

The recent development of cardiac magnetic resonance (CMR) techniques has allowed detailed analyses of cardiac function and tissue characterization with high spatial resolution. We review characteristic CMR features in ischemic and non-ischemic cardiomyopathies (ICM and NICM), especially in terms of the location and distribution of late gadolinium enhancement (LGE). CMR in ICM shows segmental wall motion abnormalities or wall thinning in a particular coronary arterial territory, and the subendocardial or transmural LGE. LGE in NICM generally does not correspond to any particular coronary artery distribution and is located mostly in the mid-wall to subepicardial layer. The analysis of LGE distribution is valuable to differentiate NICM with diffusely impaired systolic function, including dilated cardiomyopathy, end-stage hypertrophic cardiomyopathy (HCM), cardiac sarcoidosis, and myocarditis, and those with diffuse left ventricular (LV) hypertrophy including HCM, cardiac amyloidosis and Anderson-Fabry disease. A transient low signal intensity LGE in regions of severe LV dysfunction is a particular feature of stress cardiomyopathy. In arrhythmogenic right ventricular cardiomyopathy/dysplasia, an enhancement of right ventricular (RV) wall with functional and morphological changes of RV becomes apparent. Finally, the analyses of LGE distribution have potentials to predict cardiac outcomes and response to treatments.

Systematic treatment approach to ventricular tachycardia in cardiac sarcoidosis

BACKGROUND

Fatal arrhythmia is commonly observed in cardiac sarcoidosis, but clinical effects of a systematic treatment approach are still uncertain. This study sought to describe both clinical and electrophysiological characteristics and outcomes of systematic treatment approach to ventricular tachycardia (VT) associated with cardiac sarcoidosis.

METHODS AND RESULTS

We enrolled 37 consecutive patients (11 men; age, 56±11 years) with a diagnosis of sustained VT associated with cardiac sarcoidosis. Clinical effects of a systematic treatment approach including medical therapy (both steroid and antiarrhythmic agents), in association with radiofrequency catheter ablation, were evaluated. All patients received antiarrhythmic agents, and 34 received steroid therapy. During a 39-month follow-up, 23 (62%) patients were free from any VT episodes with medical therapy. Multivariable Cox regression analyses revealed that the absence of gallium-67 myocardial uptake was an independent predictor for VT recurrence (hazard ratio, 7.51; 95% confidence interval, 1.65-34.26; P<0.01). Fourteen patients who experienced VT recurrences even while on drug therapy underwent radiofrequency catheter ablation. Electrophysiological study revealed that the mechanisms of VTs could be classified into 2 subgroups: Purkinje-related or scar-related VT. The QRS duration of VT was narrower in Purkinje-related than in scar-related VTs (157±23 versus 183±22 ms; P<0.05). After a 33-month follow-up subsequent to the radiofrequency catheter ablation, 6 of 14 patients experienced VT recurrence. The number of VTs sustained during electrophysiological study was higher in the patients with VT recurrence than in those without (3.7±1.4 versus 1.9±0.8; P<0.01).

CONCLUSIONS

A systematic treatment approach to cardiac sarcoidosis with VT successfully suppressed VT recurrences in the majority of patients studied.

Edema and fibrosis imaging by cardiovascular magnetic resonance: how can the experience of Cardiology be best utilized in rheumatological practice?

OBJECTIVES

CMR, a non-invasive, non-radiating technique can detect myocardial oedema and fibrosis.

METHOD

CMR imaging, using T2-weighted and T1-weighted gadolinium enhanced images, has been successfully used in Cardiology to detect myocarditis, myocardial infarction and various cardiomyopathies.

RESULTS

Transmitting this experience from Cardiology into Rheumatology may be of important value because: (a) heart involvement with atypical clinical presentation is common in autoimmune connective tissue diseases (CTDs). (b) CMR can reliably and reproducibly detect early myocardial tissue changes. (c) CMR can identify disease acuity and detect various patterns of heart involvement in CTDs, including myocarditis, myocardial infarction and diffuse vasculitis. (d) CMR can assess heart lesion severity and aid therapeutic decisions in CTDs.

CONCLUSION

The CMR experience, transferred from Cardiology into Rheumatology, may facilitate early and accurate diagnosis of heart involvement in these diseases and potentially targeted heart treatment.

Deterioration of cardiac function during the progression of cardiac sarcoidosis: diagnosis and treatment

The cardiac involvement of sarcoidosis causes progressive heart failure symptoms and is a life-threatening condition; thus, an early and appropriate diagnosis of this condition is crucial. On the other hand, the decline in the cardiac function is rapid; therefore, patients usually have moderate-severe left ventricular dysfunction when diagnosed with cardiac sarcoidosis, which may decrease the effectiveness of therapies. We herein report three illustrative cases of heart failure due to cardiac sarcoidosis in patients who were or were not diagnosed with preceding systemic sarcoidosis. We also discuss the currently available diagnostic modalities and possible biomarkers for the diagnosis of cardiac sarcoidosis.

Extrapulmonary manifestations of sarcoidosis

Sarcoidosis is a systemic disease characterized by the development of epithelioid granulomas in various organs. Although the lungs are involved in most patients with sarcoidosis, virtually any organ can be affected. Recognition of extrapulmonary sarcoidosis requires awareness of the organs most commonly affected, such as the skin and the eyes, and vigilance for the most dangerous manifestations, such as cardiac and neurologic involvement. In this article, the common extrapulmonary manifestations of sarcoidosis are reviewed and organ-specific therapeutic considerations are discussed.

[Clinical indications for the use of cardiac MRI. By the SIRM Study Group on Cardiac Imaging]

Cardiac magnetic resonance (CMR) is considered an useful method in the evaluation of many cardiac disorders. Based on our experience and available literature, we wrote a document as a guiding tool in the clinical use of CMR. Synthetically we describe different cardiac disorders and express for each one a classification, I to IV, depending on the significance of diagnostic information expected.

Utility of cardiac magnetic resonance imaging to differentiate cardiac sarcoidosis from arrhythmogenic right ventricular cardiomyopathy

Some patients diagnosed with arrhythmogenic right ventricular cardiomyopathy (ARVC) are eventually found to have cardiac sarcoidosis (CS). Accurate differentiation between these 2 conditions has implications for immunosuppressive therapy and familial screening. We sought to determine whether cardiac magnetic resonance imaging (MRI) could be used to identify the characteristic findings to accurately differentiate between CS and ARVC. Consecutive patients with a diagnostic MRI scan indicating CS and/or ARVC constituted the cohort. All patients diagnosed with CS had histologic confirmation of sarcoidosis, and all patients with ARVC met the diagnostic task force criteria. The cardiac MRI data were retrospectively analyzed to identify possible differentiating characteristics. Of the patients, 40 had CS and 21 had ARVC. Those with CS were older and had more left ventricular scar. The presence of mediastinal lymphadenopathy or left ventricular septal involvement was seen exclusively in the patients with CS (p <0.001). A family history of sudden cardiac death was seen only in the ARVC group (p = 0.012). The right ventricular ejection fraction and ventricular volumes were also significantly different between the 2 groups. In conclusion, patients with CS have significantly different cardiac MRI characteristics than patients with ARVC. The cardiac volume, in addition to the degree and location of cardiac involvement, can be used to distinguish between these 2 disease entities. The presence of mediastinal lymphadenopathy and left ventricular septal scar favors a diagnosis of CS and not ARVC. Consideration of CS should be given if these MRI findings are observed during the evaluation for possible ARVC.

Arrhythmias in cardiac sarcoidosis: diagnosis and treatment

PURPOSE OF REVIEW

Sarcoidosis is a granulomatous disease of unclear cause and variable presentation. Cardiac involvement can result in life-threatening conditions including heart block, ventricular tachycardia, sudden cardiac death, and heart failure. There is no consensus on the diagnosis and management of cardiac sarcoidosis and a practical update is needed to provide clinicians with guidance.

RECENT FINDINGS

Three recent studies have described cardiac manifestations as the first presentation of sarcoidosis. In one study, cardiac sarcoidosis was found to be the underlying cause in 19% of adults aged less than 55 years presenting with new onset unexplained atrioventricular block. Also, there are increasing reports of patients with isolated cardiac sarcoidosis (i.e., without sarcoid in other organs). Finally, advances in imaging have enhanced our ability to detect myocardial involvement and perhaps follow response to treatment.

SUMMARY

Cardiac sarcoidosis should be considered in patients aged less than 55 years presenting with unexplained atrioventricular block and in patients with idiopathic cardiomyopathy and sustained ventricular tachycardia. Much remains to be learned about the condition, including the role of steroids and devices in treatment, and the place of advanced imaging in following the response to treatment. Collaborative multicenter studies are required to answer these important clinical questions.

Investigation of cardiomyopathy using cardiac magnetic resonance imaging part 1: Common phenotypes

Cardiac magnetic resonance imaging (CMRI) has emerged as a useful tertiary imaging tool in the investigation of patients suspected of many different types of cardiomyopathies. CMRI sequences are now of a sufficiently robust quality to enable high spatial and temporal resolution image acquisition. This has led to CMRI becoming an effective non-invasive imaging gold standard for many cardiomyopathies. In this 2-part review, we outline the typical sequences used to image cardiomyopathy, and present the imaging spectrum of cardiomyopathy. Part 1 focuses on the current classification of cardiomyopathy, basic CMRI sequences used in evaluating cardiomyopathy and the imaging spectrum of common phenotypes.

Long-term follow-up of patients with cardiac sarcoidosis and implantable cardioverter-defibrillators

BACKGROUND

Ventricular tachyarrhythmias are an important cause of morbidity and mortality in cardiac sarcoidosis. To date, the prevalence and incidence of ventricular tachycardia/ventricular fibrillation (VT/VF) in this population remain unknown.

OBJECTIVES

To determine the prevalence and incidence of ventricular tachyarrhythmias in patients with cardiac sarcoidosis and to identify the clinical attributes associated with appropriate implantable cardioverter-defibrillator (ICD) therapies.

METHODS

We studied 45 patients with ICDs, biopsy-proven systemic sarcoidosis, and cardiac involvement, as evidenced by histopathology, cardiac magnetic resonance imaging, and/or (18)F-fluoro-2-deoxyglucose-positron emission tomography imaging. Device logs and medical records were retrospectively reviewed.

RESULTS

Appropriate ICD therapies for VT/VF were observed in 37.8% of the patients with an incidence of 15% per year. Inappropriate ICD therapies occurred in 13.3% of the patients. Longer ICD follow-up (4.5 ± 3.1 years vs 1.5 ± 1.5 years; P = .001), depressed left ventricular ejection fraction (35.5% ± 15.5% vs 50.9% ± 15.5%; P = .002), and complete heart block (47.1% vs 17.9%; P = .048) were associated with appropriate ICD therapy. While there was no significant difference in the total number of shocks/antitachycardia pacing-terminated events between primary (n = 29) and secondary (n = 16) prevention groups, there was a trend toward more events in the secondary prevention arm after 2 years.

CONCLUSIONS

Ventricular tachyarrhythmias requiring ICD therapy were common in patients with cardiac sarcoidosis, with an estimated incidence rate of 15% per year. Longer follow-up, left ventricular systolic dysfunction, and complete heart block were associated with VT/VF. Patients with primary prevention ICDs had high rates of appropriate ICD therapy but not as high as did secondary prevention patients. In the absence of reliable risk stratification techniques, consideration should be given to prophylactic ICD implantation in patients with cardiac sarcoidosis.

Delayed contrast enhancement on MR images of myocardium: past, present, future

Differential enhancement of myocardial infarction was first recognized on computed tomographic (CT) images obtained with iodinated contrast material in the late 1970s. Gadolinium enhancement of myocardial infarction was initially reported for T1-weighted magnetic resonance (MR) imaging in 1984. The introduction of an inversion-recovery gradient-echo MR sequence for accentuation of the contrast between normal and necrotic myocardium was the impetus for widespread clinical use for demonstrating the extent of myocardial infarction. This sequence has been called delayed-enhancement MR and MR viability imaging. The physiologic basis for differential enhancement of myocardial necrosis is the greater distribution volume of injured myocardium compared with that of normal myocardium. It is now recognized that delayed enhancement occurs in both acute and chronic (scar) infarctions and in an array of other myocardial processes that cause myocardial necrosis, infiltration, or fibrosis. These include myocarditis, hypertrophic cardiomyopathy, amyloidosis, sarcoidosis, and other myocardial conditions. In several of these diseases, the presence and extent of delayed enhancement has prognostic implications. Future applications of delayed enhancement with development of MR imaging and CT techniques will be discussed.

Diagnosing isolated cardiac sarcoidosis

OBJECTIVES

Cardiac sarcoidosis (CS) without clinically apparent extracardiac disease may escape detection because of the poor sensitivity of endomyocardial biopsy (EMB). We set out to analyse our experience of repeated and imaging-guided biopsies in clinically isolated CS.

METHODS

We retrospectively reviewed the medical records, laboratory test results, imaging studies and pathological analyses of 74 patients with either histologically proven or clinically probable CS at our institution between January 2000 and December 2010.

RESULTS

Fifty-two patients had histologically proven CS, of whom 33 (26 women) had disease that was clinically isolated to the heart. Sarcoidosis was detected in the first EMB in 10 of the 31 patients who underwent biopsy. CS was found by repeated EMBs, targeted by cardiac imaging, in seven additional patients, and 11 patients were diagnosed by sampling 18-F-fluorodeoxyglucose position emission tomography-positive mediastinal lymph nodes at mediastinoscopy. Together, the first biopsy (cardiac or mediastinal lymph node) provided the diagnosis in 34%, the second biopsy in 31% and the third in 22% of biopsied patients with isolated CS. Four (13%) of the remaining diagnosis were made after cardiac transplantation and one in a patient who did not undergo biopsy) at autopsy after sudden cardiac death.

CONCLUSIONS

Cardiac sarcoidosis may present without clinically apparent disease in other organs. At least two-thirds of patients remain undiagnosed after a single EMB session. The detection rate can be improved by repeated and imaging-guided cardiac or mediastinal lymph-node biopsies. Nevertheless, false-negative biopsy results remain a problem in CS patients with no apparent extracardiac disease.

¹⁸F-Fluoro-2-deoxyglucose positron emission tomography in cardiac sarcoidosis

Cardiac sarcoidosis (CS) is a rare and potentially life-threatening disease that causes conduction disturbance, systolic dysfunction, and most notably sudden cardiac death. Accurate diagnosis of CS is thus mandatory; however, a reliable approach that enables diagnosis of CS with high sensitivity and specificity has yet to be established. Recent studies have demonstrated the promising potential of (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG PET) in the diagnosis and assessment of CS. Indeed, (18)F-FDG PET provides a wide variety of advantages over previous imaging modalities; however, there are pitfalls and limitations that should be recognized. In this review article, (1) the rationale for (18)F-FDG PET application in CS, (2) suitable pretest preparations, and (3) evaluation protocols for the (18)F-FDG PET images obtained will be addressed. In particular, sufficient suppression of physiological (18)F-FDG uptake in the heart is essential for accurate assessment of CS. Also, (4) recent studies addressing the diagnostic role of (18)F-FDG PET and (5) the clinically important differences between (18)F-FDG PET and other imaging technologies will be reviewed. For example, active sarcoid lesions and their response to steroid treatment will be better detected by (18)F-FDG PET, whereas fibrotic lesions might be shown more clearly by magnetic resonance imaging or other nuclear myocardial perfusion imaging. In the last decade, (18)F-FDG PET has substantially enhanced detection of CS; however, CS would be better evaluated by a combination of multiple modalities. In the future, advances in (18)F-FDG PET and other emerging imaging modalities are expected to enable better management of patients with sarcoidosis.

Multi-technique imaging of sarcoidosis

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology. The diagnosis is suggested on the basis of wide ranging clinical and radiological manifestations, and is supported by the histological demonstration of non-caseating granulomas in affected tissues. This review highlights the multisystem radiological features of the disease across a variety of imaging methods including multidetector computed tomography (CT), magnetic resonance imaging (MRI) as well as functional radionuclide techniques, particularly 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography/computed tomography (PET/CT). It is important for the radiologist to be aware of the varied radiological manifestations of sarcoidosis in order to recognize and suggest the diagnosis in the appropriate clinical setting.

Cardiac MRI evaluation of nonischemic cardiomyopathies

The purpose of this manuscript is to review the major MRI findings in patients with nonischemic cardiomyopathies. Cardiac MRI has become an integral part in the diagnosis and management of patients with nonischemic cardiomyopathies. Findings on cardiac MRI studies can help distinguish between different types of cardiomyopathies and can provide valuable diagnostic and prognostic information.

Identifying the etiology: a systematic approach using delayed-enhancement cardiovascular magnetic resonance

In patients who have heart failure, treatment and survival are directly related to the cause. Clinically, as a practical first step, patients are classified as having either ischemic or non-ischemic cardiomyopathy, a delineation usually based on the presence or absence of epicardial coronary artery disease. However, this approach does not account for patients with non-ischemic cardiomyopathy who also have coronary artery disease, which may be either incidental or partly contributing to myocardial dysfunction (mixed cardiomyopathy). By allowing direct assessment of the myocardium, delayed-enhancement cardiovascular magnetic resonance (DE-CMR) may aid in addressing these conundrums. This article explores the use of DE-CMR in identifying ischemic and non-ischemic myopathic processes and details a systematic approach to determine the cause of cardiomyopathy.

Functional imaging of inflammatory diseases using nuclear medicine techniques

Molecular imaging with positron emission tomography (PET) and single-photon emission computed tomography (SPECT) is increasingly used to diagnose, characterize, and monitor disease activity in the setting of inflammatory disorders of known and unknown etiology. These disorders include sarcoidosis, atherosclerosis, vasculitis, inflammatory bowel disease (IBD), rheumatoid arthritis (RA), and degenerative joint disease. Gallium-67 ((67)Ga) citrate, labeled leukocytes with technetium-99m ((99m)Tc) or indium-111 ((111)In), and (18)F-fluorodeoxyglucose (FDG) represent the most widely used radiopharmaceutical agents. However, other preparations, such as labeled murine monoclonal antigranulocyte antibodies and labeled human polyclonal nonspecific immunoglobulin G, chemotactic peptides, interleukins, chemokines, and liposomes, have been used to image inflammation. Also, (99m)Tc nanocolloid scintigraphy has been found to be suitable for bone and joint diseases, especially RA. Among the single photon emitting imaging agents, the recommended radiotracer for abdominal inflammation has been (99m)Tc-hexamethylpropylene amine oxime (HMPAO)-labeled leukocytes. During the last several years, FDG-PET imaging has been shown to have great value for the detection of inflammation and has become the centerpiece of such initiatives. This very powerful technique will play an increasingly important role in the management of patients with inflammatory conditions. FDG-PET can provide valuable information in patients with pulmonary and extrapulmonary sarcoidosis, and is a useful tool for testing the efficacy of various treatments. FDG-PET combined with computed tomography holds great promise for assessing atherosclerosis of the large arteries. This modality is very sensitive in detecting large-vessel vasculitis and can be used to monitor the disease course. FDG-PET is also being used to study the inflamed synovial joints both in the experimental and clinical settings, especially for the investigation and management of RA and degenerative joint disease. This technique also has the potential to become the imaging modality of choice in assessing IBD, replacing radiolabeled autologous leukocyte imaging in this setting. Detection of inflammation in the lungs and airways may improve our knowledge about a multitude of disorders that affect these structures. Therefore, functional imaging, led by FDG-PET imaging, is likely to play an increasingly critical role in assessing inflammatory disorders of known and unknown etiologies, and will improve their management immensely in the future.