John P. Bois

Benign lipomatous masses of the heart: a comprehensive series of 47 cases with cytogenetic evaluation ☆

Benign lipomatous lesions of the heart encompass an apparently etiologically diverse group of entities including neoplastic, congenital, and reparative phenomena. Among these, lipomas and lipomatous hypertrophy of the atrial septum (LHAS) represent 2 commonly encountered mass lesions. To date, no study has systematically and comparatively evaluated the morphologic and genetic characteristics of these lesions. Tissue registry archives of Mayo Clinic were queried for cases of cardiac lipoma and LHAS (1994-2011). Clinical, imaging, and pathologic findings were reviewed. Representative cases in each cohort were evaluated by fluorescence in situ hybridization (FISH) for HMGA1 and HMGA2 loci rearrangement and for MDM2/CPM locus amplification. Five cases of cardiac lipoma were identified (mean age, 67 years; range, 48-101; 3 men): 4 right atrial and 1 left ventricular. Forty-two cases of LHAS were identified (mean age, 75.6 years; range 45-95; 20 men), 39 of which were autopsy derived. The median size was 3.4 cm for lipomas and 2.8 cm for LHAS (n = 14). A single case each of cardiac lipoma and LHAS were found to harbor HMGA2 rearrangement, whereas no case showed cytogenetic abnormality of HMGA1 or CPM. This represents the largest series of histopathologically confirmed cardiac lipomas from a single institution. In addition, it is the first to evaluate cardiac lipomas and LHAS for genetic alterations associated with extracardiac lipomatous lesions. The genetic and morphologic similarities found provide evidence in support of the neoplastic classification of cardiac lipomas. A single case of LHAS contained an HMGA2 rearrangement, challenging the currently accepted hypothesis of pathogenesis for this lesion.

Optimizing radionuclide imaging in the assessment of cardiac sarcoidosis

Sarcoidosis is a disease of unknown etiology and is characterized by the development of non-caseating granulomas with a predilection for the pulmonary system. Involvement of the cardiovascular system ranges from 20% in the United States to over 75% in Japan. Up to 85% of sarcoid-related mortality results from cardiac sarcoidosis (CS). Observational studies suggest that early initiation of glucocorticoids may inhibit the inflammatory response to CS, thereby limiting fibrotic formation within the heart and ultimately improving long-term survival. Consequently, prompt and accurate diagnosis of CS is critical given its prognostic and therapeutic ramifications. Unfortunately, the diagnosis of CS has proven challenging since approximately half the of patients with CS are initially asymptomatic and, due to heterogenous myocardial involvement, CS detection by endomyocardial biopsy (EMB) has a sensitivity of only 20% to 30%. Gallium (Ga) singlephoton emission tomography (SPECT) is specific for CS but has a sensitivity of less than 40%. Non-radionuclide techniques for the diagnosis of CS include echocardiography which has a poor sensitivity (25%) and cardiac MRI which has substantially greater sensitivity for CS detection at 75% but may be contraindicated in some patients with suspected CS such as those with cardiac devices. Cardiac imaging with fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) appears to have high diagnostic accuracy for CS as demonstrated in several observational studies. Consequently, experts have recently included cardiacFDGPET imaging in the standard diagnostic algorithm for CS. The gradual adoption of cardiacFDG-PET imaging as a standard of care in the assessment and treatment of CS underscores the need for studies focusing on standardization of patient preparation, imaging protocols, and interpretation of cardiacFDGPET imaging for CS. An important component of cardiac imaging with FDG-PET is patient preparation. The objective of patient preparation for an FDG-PET CS imaging protocol is to suppress physiologic myocardial FDG uptake in order to enhance detection of pathologic FDG uptake in inflamed tissues. Under postprandial conditions, increased serum insulin levels upregulate glucose transporter 1 and 2 (GLUT-1 and GLUT-2) which in turn facilitate myocyte glucose uptake. Therefore, diffuse myocardial FDG uptake in the nonfasting state may be a normal physiologic finding. In some healthy individuals, FDG uptake may be more heterogeneous, and may be present even in the fasting state. At the same time, inflamed tissue, such as that seen in CS, can also increase glucose utilization and result in elevated intramyocardial levels of FDG. The appearance of FDG uptake in inflamed tissues may be indistinguishable from heterogeneous or focal FDG uptake in healthy myocardium, underscoring the importance of suppression of normal physiologic myocardial FDG uptake. Current means of suppressing physiologic myocardial FDG uptake for CS PET imaging include (1) prolonged fasting, (2) low-carbohydrate diet (LCD) with or without high fat, and/or (3) use of intravenous unfractionated heparin (UFH) to stimulate lipolytic activity and increase free fatty acid (FFA) levels. Limited studies suggest varying degrees of efficacy of these protocols. Similarly, prior studies using other means of physiologic suppression such as shorter fasting protocols have noted varying degrees of myocardial FDG uptake in a majority of patients, Reprint requests: Panithaya Chareonthaitawee, MD, Division of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905; chareonthaitawee.panithaya@mayo.edu J Nucl Cardiol 2016;23:253–5. 1071-3581/

Low incidence of left atrial delayed enhancement with MRI in patients with AF: A single-centre experience

34.00 Copyright 2015 American Society of Nuclear Cardiology.

Spectrum of Aortic Disease in the Giant Cell Arteritis Population

Background Atrial fibrillation (AF) is the most common sustained atrial arrhythmia. One potential target for ablation is left atrial (LA) scar (LAS) regions that may be the substrate for re-entry within the atria, thereby sustaining AF. Identification of LAS through LA delayed gadolinium enhancement (LADE) with MRI has been proposed. Objectives We sought to evaluate LADE in patients referred for catheter ablation of AF. Methods Prospective analysis was conducted of consecutive patients who underwent pulmonary vein antrum isolation (PVAI) ablation for AF at a single institution. Patients underwent LADE with MRI to determine LAS regions before ablation. MRI data were analysed independently in accordance with prespecified institutional protocol by two staff cardiac radiologists to whom patient outcomes were masked, and reports of LADE were documented. Where no initial consensus occurred regarding delayed enhancement (DE), a third staff cardiac radiologist independently reviewed the case and had the deciding vote. Results Of the 149 consecutive patients (mean (SD) age, 59 (9) years), AF was persistent in 64 (43%) and paroxysmal in 85 (57%); 45 (30%) had prior ablation. Only five patients (3%) had identifiable DE in LA walls (persistent AF, n=1; paroxysmal AF, n=4). LADE was present in two (4%) of the 45 patients with previous left PVAI. The presence of LADE was not associated with a higher recurrence rate of AF. Conclusions In contrast to previous studies, the finding of DE within LA walls was uncommon and, when present, did not correlate with AF type or risk of AF recurrence. It therefore is of unclear clinical significance.

Multimodality imaging of foreign bodies in and around the heart

We report the spectrum of aortic involvement in patients with giant cell arteritis (GCA) following review of medical records of 4,006 patients including those with imaging studies. A total of 1,450 patients (36%) had a confirmed diagnosis of GCA. Of these, 974 had aortic imaging. Of the 974 patients with imaging, 435 (45%) had an identified aortopathy. The most common aortopathy was aneurysm/dilation (69%). Overall, an annual aneurysmal growth rate of 1.5 mm/y was calculated. In patients with aneurysm/dilation, aortic dissection occurred in 18 patients (6%), and these patients had a significantly higher aneurysmal growth rate compared with those without dissection (4.5 vs 1.4 mm/y, p = 0.005). The median size of the aorta at the time of dissection was 51 mm, with 7 (39%) occurring with a maximal aortic aneurysm/dilation <50 mm. In conclusion, our findings indicate higher aneurysmal growth rate in GCA compared with that reported for degenerative aortic disease. Moreover, patients who develop dissection had a significantly higher growth rate than those without dissection with over a third of these patients suffering dissection at a caliber <50 mm.

Continuing evolution in preparation protocols for 18FDG PET assessment of inflammatory or malignant myocardial disease

Foreign objects are occasionally seen on computed tomography and could pose a diagnostic challenge to the radiologist and clinicians. It is important to recognize, characterize and localize these objects and determine their clinical significance. Most foreign objects in and around the heart are the result of direct penetrating injury or represent venous embolization to the heart. Foreign objects may cause symptoms and require prompt medical attention or maybe asymptomatic. Clinicians should be familiar with foreign objects that are encountered and understand treatment options. This paper looks at some of foreign objects that can be found and correlates with pathology where possible.

Radionuclide Imaging in Congestive Heart Failure Assessment of Viability, Sarcoidosis, and Amyloidosis

Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging is growing as a standard diagnostic tool in patients with cardiac sarcoidosis (CS) and is an emerging imaging modality in other challenging patient populations including those with myocarditis, neoplastic cardiac disease, and cardiac allograft rejection. Ultimately, widespread implementation and clinical utilization of FDG PET imaging for these indications is predicated upon both optimization and standardization of patient preparation protocols. As a result, FDG PET protocol optimization has been an active area of research, with recent publications in the Journal of Nuclear Cardiology focusing on preparations to suppress physiologic myocardial glucose uptake. In a recent publication in the journal, Manabe et al. assessed combined prolonged fasting, low-carbohydrate diet, and heparin administration, whereas in the current issue of the journal, Nensa and colleagues examined the efficacy of a C24-hour high-fat, low-carbohydrate, protein-permitted (HFLCPP) diet combined with heparin administration. The objective of patient preparation protocols in inflammatory cardiac conditions is the suppression of physiologic myocardial FDG uptake, thereby allowing detection of FDG in pathologic tissue. In the physiologic postprandial state, heightened serum insulin levels stimulate glucose transport 1 and 2 (GLUT 1 and 2) which consequently enhance myocyte glucose importation. As a result, diffuse myocardial FDG PET uptake after a meal is likely a physiologic response and a nonpathologic finding. At the same time, inflamed myocardial tissue may also demonstrate enhanced glucose uptake and thus may be indistinguishable from healthy myocytes in a patient who has recently ingested a carbohydrate-rich meal. Proposed means by which to suppress physiologic myocardial glucose uptake include (1) prolonged fasting, (2) lowcarbohydrate diet (LCD) with or without high fat, and/ or (3) the use of intravenous unfractionated heparin (UFH) to increase free fatty acid (FFA) levels via lipolytic activity. Contemporary areas of investigation have focused on potential combinations of these preparation protocols. In this issue of the journal, Nensa and colleagues evaluate the efficacy of a C24-hour HFLCPP diet accompanied by administration of UFH for suppression of physiologic myocardial glucose uptake in 89 consecutive patients suspected to have either myocarditis, cardiac tumors, sarcoidosis, or cardiac allograft rejection. Each patient was provided with instructions outlining the appropriate diet, and received UFH shortly before undergoing FDG PET magnetic resonance imaging (MRI). Each study was subsequently evaluated both qualitatively and quantitatively for assessment of sufficient suppression of physiologic myocardial uptake with the authors reporting an 84% success rate. Nensa and colleagues are commended on several aspects of their work. First, their diligence in creating a patient ‘‘menu’’ for each study participant is a critical first step toward ensuring compliance to the recommended diet and standardization. Second, the authors utilized quantitative assessment of FDG uptake by calculating standard uptake value. In the CS population, use of quantitative FDG PET improves specificity from 46% to 97% without diminishing test sensitivity. Third, Nensa et al. employed hybrid imaging by Reprint requests: Panithaya Chareonthaitawee, MD, Department of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905; Chareonthaitawee.Panithaya@mayo.edu J Nucl Cardiol 2017;24:989–92. 1071-3581/

Microvascular obstruction in non-infarct related coronary arteries is an independent predictor of major adverse cardiovascular events in patients with ST segment-elevation myocardial infarction

34.00 Copyright 2016 American Society of Nuclear Cardiology.

Contemporary Advances in Myocardial Metabolic Imaging and Their Impact on Clinical Care: a Focus on Positron Emission Tomography (PET)

Radionuclide imaging provides both established and emerging diagnostic and prognostic tools to assist clinicians in the management of patients with ischemic cardiomyopathy, cardiac sarcoidosis, and cardiac amyloidosis. This review highlights the underlying pathophysiology of each entity and associated diagnostic and clinical challenges, and describes the available radionuclide imaging techniques. Specific protocols, advantages and disadvantages, comparison with other noninvasive imaging modalities, and discussion of the evolving role of hybrid imaging are also included.

Hydroxychloroquine-Mediated Cardiotoxicity With a False-Positive 99m Technetium–Labeled Pyrophosphate Scan for Transthyretin-Related Cardiac Amyloidosis

BACKGROUND Coronary microvascular obstruction (MVO) in infarct-related artery (IRA) territory has been associated with worse cardiovascular outcomes in patients presenting with ST-segment elevation myocardial infarction. However, the prognostic value of non-IRA MVO in this patient population remains unknown. METHODS AND RESULTS One hundred ninety nine patients presenting to our institution with STEMI were enrolled. All patients underwent primary percutaneous coronary intervention per institutional STEMI protocol followed by a cardiac MRI within 1 week of presentation and the IRA and non-IRA MVO segments were determined. All cause death, recurrent myocardial infarction, hospitalization for heart failure, and ventricular tachycardia were counted as major adverse cardiovascular events (MACE). Patients with non-IRA MVO had lower composite MACE free survival at 6 months (HR 2.15, 95% CI, 1.06-4.35; p = 0.029) compared to those without non-IRA MVO. In a sub-analysis of patients with multi vessel disease (MVD), patients with non-IRA MVO also had lower composite MACE-free survival at 6 months as compared to those without non-IRA MVO (HR 2.47, 95% CI, 1.02-5.97; p = 0.037). Non-IRA MVO continued to be predictive of MACE in a cox proportional hazards model adjusting for additional prognostic factors using inverse probability weighting (p = 0.007). Non-IRA MVO was more prevalent in patients with LAD culprit vessel STEMI rather than those with RCA or Circumflex culprit vessels (p < 0.001). CONCLUSIONS Patients presenting with STEMI and non-IRA MVO have significantly lower MACE free survival at 6 months as compared to those without non-IRA MVO.