Cardiac Amyloidosis

Role of endogenous T1ρ and its dispersion imaging in differential diagnosis of cardiac amyloidosis

BACKGROUND

Cardiovascular magnetic resonance (CMR) has demonstrated excellent performance in the diagnosis of cardiac amyloidosis (CA). However, misdiagnosis occasionally occurs because the morphological and functional features of CA are non-specific. This study was performed to determine the value of non-contrast CMR T1ρ in the diagnosis of CA.

METHODS

This prospective study included 45 patients with CA, 30 patients with hypertrophic cardiomyopathy (HCM), and 10 healthy controls (HCs). All participants underwent cine (whole heart), T1ρ mapping, pre- and post-contrast T1 mapping imaging (three slices), and late gadolinium enhancement using a 3T whole-body MRI system. All participants underwent T1ρ at two spin-locking frequencies: 0Hz and 298Hz. ECV maps were obtained using pre- and post-contrast T1 maps. The myocardial T1ρ dispersion map, termed myocardial dispersion index (MDI), was also calculated. All parameters were measured in the left ventricular myocardial wall. Participants in the HC group were scanned twice on different days to assess the reproducibility of T1ρ measurements.

RESULTS

Excellent reproducibility was observed upon evaluation of the coefficient of variation between two scans (T1ρ [298Hz]: 3.1%; T1ρ [0Hz], 2.5%). The ECV (HC: 27.4 ± 2.8% vs. HCM: 32.6 ± 5.8% vs. CA: 46 ± 8.9%; p < 0.0001), T1ρ [0Hz] (HC: 35.8 ± 1.7 ms vs. HCM: 40.0 ± 4.5 ms vs. CA: 51.4 ± 4.4 ms; p < 0.0001) and T1ρ [298Hz] (HC: 41.9 ± 1.6 ms vs. HCM: 48.8 ± 6.2 ms vs. CA: 54.4 ± 5.2 ms; p < 0.0001) progressively increased from the HC group to the HCM group, and then the CA group. The MDI progressively decreased from the HCM group to the HC group, and then the CA group (HCM: 8.8 ± 2.8 ms vs. HC: 6.1 ± 0.9 ms vs. CA: 3.4 ± 2.1 ms; p < 0.0001). For differential diagnosis, the combination of MDI and T1ρ [298Hz] showed the greatest sensitivity (98.3%) and specificity (95.5%) between CA and HCM, compared with the native T1 and ECV.

CONCLUSIONS

The T1ρ and MDI approaches can be used as non-contrast CMR imaging biomarkers to improve the differential diagnosis of patients with CA.

Moving towards establishing centres of excellence in cardiac amyloidosis: an International Cardio-Oncology Society statement

The prevalence of amyloidosis has been increasing, driven by a combination of improved awareness, evolution of diagnostic pathways, and effective treatment options for both transthyretin and light chain amyloidosis. Due to the complexity of amyloidosis, centralised expert providers with experience in delineating the nuances of confirmatory diagnosis and management may be beneficial. There are many potential benefits of a centre of excellence designation for the treatment of amyloidosis including recognition of institutions that have been leading the way for the optimal treatment of this condition, establishing the expectations for any centre who is engaging in the treatment of amyloidosis and developing cooperative groups to allow more effective research in this disease space. Standardising the expectations and criteria for these centres is essential for ensuring the highest quality of clinical care and community education. In order to define what components are necessary for an effective centre of excellence for the treatment of amyloidosis, we prepared a survey in cooperation with a multidisciplinary panel of amyloidosis experts representing an international consortium. The purpose of this position statement is to identify the essential elements necessary for highly effective clinical care and to develop a general standard with which practices or institutions could be recognised as a centre of excellence.

Atypical Case of Wild-Type Cardiac Amyloidosis with Septal Predominance and a Nonapical Sparing Strain Pattern

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We present an atypical variant case of wild-type transthyretin cardiac amyloidosis.

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Amyloid deposition occurred mainly in the interventricular septum.

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The classic apical sparing pattern was absent, despite other suggestive findings.

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A high index of suspicion for amyloid should still be sought in such cases.

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Multimodality imaging should be considered to investigate variant amyloid forms.

Role of imaging for diagnosis and management of aortic valve papillary fibroelastoma and cardiac amyloid light chain amyloidosis: a case report

Background

We report the case of a patient who presented with concomitant aortic valve papillary fibroelastoma (PFE) and cardiac amyloidosis. Although histologically benign, PFE confers an increased thromboembolic risk, and surgical excision is often indicated. However, outcomes of cardiac surgery are poor in patients with cardiac amyloidosis.

Case summary

A 61-year-old man with complaints of dyspnoea and weight loss of 10 kg developing over the past 5 months was evaluated in the cardiology clinic. Echocardiography revealed sessile aortic valve PFE and was also highly suggestive of cardiac amyloidosis. The diagnosis of amyloid light chain amyloidosis secondary to indolent multiple myeloma was eventually confirmed. Therapy with daratumumab, bortezomib, cyclophosphamide, and dexamethasone allowed full remission over a 6-month period and resulted in marked improvement in symptoms and cardiac function as evaluated by global longitudinal strain. Further workup with cerebral magnetic resonance revealed multiple vascular sequelae. Surgical removal of the aortic fibroelastoma with bioprosthetic aortic valve replacement was performed successfully and the patient had an uneventful recovery.

Discussion

Papillary fibroelastoma and cardiac amyloidosis are rare and most likely unrelated entities. Concomitant presentation of both conditions in the same patient presents a unique therapeutic challenge. By allowing cardiac function to be monitored during chemotherapy, speckle-tracking echocardiography can prove instrumental in determining the optimal timing of surgical intervention.

Amyloidosis: Multisystem Spectrum of Disease with Pathologic Correlation

Amyloidosis is a group of conditions defined by extracellular deposition of insoluble proteins that can lead to multiorgan dysfunction and failure. The systemic form of the disease is often associated with a plasma cell dyscrasia but may also occur in the setting of chronic inflammation, long-term dialysis, malignancy, or multiple hereditary conditions. Localized forms of the disease most often involve the skin, tracheobronchial tree, and urinary tract and typically require tissue sampling for diagnosis, as they may mimic many conditions including malignancy at imaging alone. Advancements in MRI and nuclear medicine have provided greater specificity for the diagnosis of amyloidosis involving the central nervous system and heart, potentially obviating the need for biopsy of the affected organ in certain circumstances. Specifically, a combination of characteristic findings at noninvasive cardiac MRI and skeletal scintigraphy in patients without an underlying plasma cell dyscrasia is diagnostic for cardiac transthyretin amyloidosis. Histologically, the presence of amyloid is denoted by staining with Congo red and a characteristic apple green birefringence under polarized light microscopy. The imaging features of amyloid vary across each organ system but share some common patterns, such as soft-tissue infiltration and calcification, that may suggest the diagnosis in the appropriate clinical context. The availability of novel therapeutics that target amyloid protein fibrils such as transthyretin highlights the importance of early diagnosis. Online supplemental material is available for this article. ^©RSNA, 2021.