MR findings in cardiac amyloidosis

Role of Cardiovascular Magnetic Resonance in Cardiac Amyloidosis: A Narrative Review

Amyloidosis is a rare infiltrative condition resulting from the extracellular accumulation of amyloid fibrils at the cardiac level. It can be an acquired condition or due to genetic mutations. With the progression of imaging technologies, a non-invasive diagnosis was proposed. In this study, we discuss the role of CMR in cardiac amyloidosis, focusing on the two most common subtypes (AL and ATTR), waiting for evidence-based guidelines to be published.

Feature tracking cardiac magnetic resonance imaging to assess cardiac manifestations of systemic diseases

Feature-tracking cardiac magnetic resonance (FT-CMR), with the ability to quantify myocardial deformation, has a unique role in the evaluation of subclinical myocardial abnormalities. This review aimed to evaluate the clinical use of cardiac FT-CMR-based myocardial strain in patients with various systemic diseases with cardiac involvement, such as hypertension, diabetes, cancer-therapy-related toxicities, amyloidosis, systemic scleroderma, myopathies, rheumatoid arthritis, thalassemia major, and coronavirus disease 2019 (COVID-19). We concluded that FT-CMR-derived strain can improve the accuracy of risk stratification and predict cardiac outcomes in patients with systemic diseases prior to symptomatic cardiac dysfunction. Furthermore, FT-CMR is particularly useful for patients with diseases or conditions which are associated with subtle myocardial dysfunction that may not be accurately detected with traditional methods. Compared to patients with cardiovascular diseases, patients with systemic diseases are less likely to undergo regular cardiovascular imaging to detect cardiac defects, whereas cardiac involvement in these patients can lead to major adverse outcomes; hence, the importance of cardiac imaging modalities might be underestimated in this group of patients. In this review, we gathered currently available data on the newly introduced role of FT-CMR in the diagnosis and prognosis of various systemic conditions. Further research is needed to define reference values and establish the role of this sensitive imaging modality, as a robust marker in predicting outcomes across a wide spectrum of patients.

Feasibility of Hepatic T1-Mapping and Extracellular Volume Quantification on Routine Cardiac Magnetic Resonance Imaging in Patients with Infiltrative and Systemic Disorders

RATIONALE AND OBJECTIVES

Cardiac magnetic resonance imaging (CMR) is commonly obtained to evaluate for myocardial infiltrative disorders and fibrosis. Pre- and post-Gadolinium contrast T1-mapping sequences are employed to estimate interstitial expansion using extracellular volume fraction (ECV). Given the proximity of the liver to the heart, T1 and ECV quantification of the liver is feasible on CMR. The purpose of this study was to evaluate for hepatic measures of fibrosis and interstitial expansion in patients with amyloidosis or systemic disease on CMR.

MATERIALS AND METHODS

Myocardial and hepatic native T1 values were measured retrospectively using a cardiac short axis modified Look-Locker inversion recovery sequence. Myocardial and hepatic ECV were calculated using pre- and post-contrast T1 and blood pool values according to the following formula: ECV = (Δ(1/T1) myocardium or liver and/or Δ(1/T1) blood)x(1 - hematocrit). Patients were divided into three cohorts by final diagnosis: amyloidosis, systemic disease (e.g. sarcoid, scleroderma), and controls (EF > 50, no ischemia).

RESULTS

Of the 135 patients who underwent CMR, 22 had cardiac amyloidosis (age 59.9 ± 12.6 yrs, 41% female), 20 had systemic disease (age 50.9 ± 13.4 yrs, 35% female), and 93 were controls (age 49.5 ± 17.3 yrs, 50% female). Myocardial T1 and ECV values were highest for patients with amyloid, second highest for systemic disease, and least for controls (T1: 1169 ± 92 vs 1101 ± 53 vs 1027 ± 73 ms, p < 0.0001; ECV: 0.47 ± 0.11 vs 0.31 ± 0.05 vs 0.27 ± 0.04, p < 0.0001). Hepatic T1 and ECV were similarly higher in patients with amyloid and systemic disease compared to controls (T1: 646 ± 101 vs 660 ± 93 vs 595 ± 58 ms, p < 0.0001; ECV: 0.38 ± 0.08 vs 0.37 ± 0.05 vs 0.31 ± 0.03, p < 0.0001). There was a positive correlation between hepatic T1 and ECV (R² = 0.282, p < 0.0001). No patients had abnormal liver function tests or clinical liver disease.

CONCLUSION

Hepatic ECV quantification on CMR in patients with amyloidosis and systemic disorders is feasible. Further longitudinal investigation regarding detection of early or subclinical liver disease is warranted.

Multi-parametric speckle tracking analyses to characterize cardiac amyloidosis: a comparative study of systolic left ventricular longitudinal myocardial mechanics

Cardiac amyloidosis (CAM), the most common cardiac storage disease is associated with significant changes in left-ventricular (LV) morphology and function. To gain particular insights into LV systolic longitudinal myocardial mechanics we investigated seven parameters derived by speckle-tracking-echocardiography (STE) in patients with confirmed CAM (n = 59). The results were compared with those of individuals with healthy heart (n = 150) and another primary myocardial disease with also thickened myocardium and severe diastolic and systolic LV-dysfunction (symptomatic LV-non-compaction-cardiomyopathy, LV-NC, n = 30). In addition to standard echocardiographical measures, the STE-derived data were evaluated and documented utilizing polar-diagrams to obtain overviews of longitudinal myocardial mechanics of the entire LV. Compared with healthy individuals, patients with CAM and LV-NC showed significantly reduced LV-ejection-fraction (EF), global longitudinal systolic peak-strain, strain-rate, and displacement. Pre-systolic stretch-index, post-systolic index, and the EF/global peak-longitudinal-strain-ratio (EF/S) were increased. In contrast to healthy-hearts and the LV-NC group only patients with CAM demonstrated significantly reduced time-to-peak systolic longitudinal strain and time-to-peak strain-rate. Although the level of the segmental values in longitudinal mechanics was significantly different between the groups, comparable intraventricular baso-apical parameter-gradients were found for systolic longitudinal peak-strain and strain-rate, pre-systolic-stretch-index, post-systolic-index, and peak systolic displacement. Compared to ATTR-amyloidosis (ATTR-CAM), patients with AL-amyloidosis (AL-CAM) demonstrated significantly lower end-diastolic and end-systolic LV-volumes, LV-mass-indices, relative apical strain, time-to-peak systolic longitudinal strain, and time-to-peak longitudinal strain-rate. CAM and LV-NC demonstrated altered myocardial mechanics with significantly different STE-derived echocardiographical parameters. ATTR-amyloidosis and AL-amyloidosis had at least significantly different time-to-peak strain, time-to-peak strain-rate and relative apical sparing values.

Magnetic Resonance Imaging in Cardiac Amyloidosis: Unraveling the Stealth Entity

Amyloidosis is a systemic disease involving many organs. Cardiac involvement is a significant cause of morbidity and mortality in these patients. Diagnosis of cardiac amyloidosis is based on endomyocardial biopsy which however is invasive and associated with complications. Noninvasive methods of diagnosis include magnetic resonance imaging (MRI) with various methods and sequences involved. Our study aims at describing MRI features of cardiac amyloidosis including new imaging sequences and to prognosticate the patients based on imaging features. We included 35 patients with suspected cardiac amyloidosis who underwent MRI at our center over 4 years. All images were retrieved from our archive and assessed by an experienced radiologist. Common morphological features in our patients included increased wall thickness of left ventricle (LV) (16. 1 ± 4.1 mm), right ventricle (RV) (6.3 ± 1.1 mm), and interatrial septum (6.2 ± 0.8 mm). Global late gadolinium enhancement (LGE) ( n  = 21 [65%]) including subendocardial or transmural was the most common pattern followed by patchy enhancement. Global transmural LGE was associated with worse prognosis. Four types of myocardial nulling patterns were observed on postcontrast time to invert (TI) scout imaging: normal nulling pattern (myocardium nulls after blood and coincident with spleen) and abnormal nulling pattern (ANP) which is further divided into three types: Type 1-myocardium nulls before blood pool but coincident with spleen, Type 2-myocardium nulling coincident with blood but not coincident with spleen, and Type 3-features of both Type 1 and Type 2. Type 3 ANP was the most common ( n  = 23) nulling pattern in our patients. Cardiac MRI is an essential in noninvasive diagnosis of cardiac amyloidosis. Transmural global LGE serves as a poor prognosticator in these patients. "Three-tier" TI scout imaging is essential to avoid false-negative enhancement results. Type 3 ANP is the most specific nulling pattern in cardiac amyloidosis.

Regional Amyloid Burden Differences Evaluated Using Quantitative Cardiac MRI in Patients with Cardiac Amyloidosis

Objective

This study aimed to investigate the regional amyloid burden and myocardial deformation using T1 mapping and strain values in patients with cardiac amyloidosis (CA) according to late gadolinium enhancement (LGE) patterns.

Materials and Methods

Forty patients with CA were divided into 2 groups per LGE pattern, and 15 healthy subjects were enrolled. Global and regional native T1 and T2 mapping, extracellular volume (ECV), and cardiac magnetic resonance (CMR)-feature tracking strain values were compared in an intergroup and interregional manner.

Results

Of the patients with CA, 32 had diffuse global LGE (group 2), and 8 had focal patchy or no LGE (group 1). Global native T1, T2, and ECV were significantly higher in groups 1 and 2 than in the control group (native T1: 1384.4 ms vs. 1466.8 ms vs. 1230.5 ms; T2: 53.8 ms vs. 54.2 ms vs. 48.9 ms; and ECV: 36.9% vs. 51.4% vs. 26.0%, respectively; all, p < 0.001). Basal ECV (53.7%) was significantly higher than the mid and apical ECVs (50.1% and 50.0%, respectively; p < 0.001) in group 2. Basal and mid peak radial strains (PRSs) and peak circumferential strains (PCSs) were significantly lower than the apical PRS and PCS, respectively (PRS, 15.6% vs. 16.7% vs. 26.9%; and PCS, −9.7% vs. −10.9% vs. −15.0%; all, p < 0.001). Basal ECV and basal strain (2-dimensional PRS) in group 2 showed a significant negative correlation (r = −0.623, p < 0.001). Group 1 showed no regional ECV differences (basal, 37.0%; mid, 35.9%; and apical, 38.3%; p = 0.184).

Conclusion

Quantitative T1 mapping parameters such as native T1 and ECV may help diagnose early CA. ECV, in particular, can reflect regional differences in the amyloid deposition in patients with advanced CA, and increased basal ECV is related to decreased basal strain. Therefore, quantitative CMR parameters may help diagnose CA and determine its severity in patients with or without LGE.

Chemotherapy-associated nonbacterial thrombotic endocarditis: A radiological mimicker of cardiac amyloidosis requiring histopathologic examination for definitive diagnosis

Nonbacterial thrombotic endocarditis is a form of a thrombotic angiopathy involving the endothelial lined endocardial surfaces of the heart which includes valves and the chamber walls. Underlying etiologies for nonbacterial thrombotic endocarditis include autoimmune diseases, hypercoagulable states, in the setting of certain malignant neoplasms, and physical injury. The pathogenesis for these processes is that of primary endothelial injury resulting in a thrombotic angiopathy. We present a patient with heart failure being evaluated before hematopoietic stem cell transplantation who had previously been provided with chemotherapy and whose cardiac magnetic resonance imaging reveals findings suggestive of amyloidosis. A subsequent endomyocardial biopsy instead showed nonbacterial thrombotic endocarditis characterized by the endocardium with fibromyxoid thickening and overlying fresh fibrin. This case highlights histopathologic findings of chemotherapy-associated nonbacterial thrombotic endocarditis involving the right ventricle wall of the endocardium, therefore expanding the radiological differential in patients with cardiac magnetic resonance imaging findings suggestive of amyloidosis.

What the Intensivists Need to Know About Critically Ill Myeloma Patients

Multiple myeloma (MM) is a hematological malignancy characterized by an increase in aberrant plasma cells in the bone marrow leading to rising monoclonal protein in serum and urine. With the introduction of novel therapies with manageable side effects, this incurable disease has evolved into a chronic disease with an acceptable quality of life for the majority of patients. Accordingly, management of acute complications is fundamental in reducing the morbidity and mortality in MM. MM emergencies include symptoms and signs related directly to the disease and/or to the treatment; many organs may be involved including, but not limited to, renal, cardiovascular, neurologic, hematologic, and infectious complications. This review will focus on the numerous approaches that are aimed at managing these complications.

Isolated atrial amyloid: a potential contributor to morbidity and mortality following cardiac surgery

OBJECTIVES

Diffuse cardiac amyloidosis is a significant diagnosis with a poor prognosis. Isolated atrial amyloidosis (IAA) is the most common form of cardiac amyloidosis caused by accumulation of alpha-atrial natriuretic peptide. IAA has been associated with dysrhythmia, but otherwise remains a poorly characterized condition. The impact of incidental IAA on postoperative outcome following cardiac surgery has not previously been reported. The purpose of this study was to examine the impact of isolated atrial amyloid on patient outcomes following cardiac surgery.

METHODS

A retrospective analysis was performed of all patients having excision of the left atrial appendage during cardiac surgery at our centre over a 5-year period. Patients with histological evidence of IAA were compared to patients without this diagnosis. IAA was diagnosed by immunohistochemistry for atrial natriuretic peptide.

RESULTS

A total of 167 patients underwent left atrial appendage excision and of these 26 (15.6%) were found to have IAA. Preoperative characteristics were similar between the 2 groups. A significantly greater proportion of patients with IAA experienced dysrhythmia requiring implantation of a permanent pacemaker (23.1% vs 7.8%, P = 0.03). There was also a significantly elevated incidence of perioperative death in the IAA group (11.5% vs 1.4%, P = 0.03) and inferior 1-year survival (84.6% vs 96.5%, P = 0.02).

CONCLUSIONS

The presence of IAA may be associated with inferior outcomes following cardiac surgery, with increased morbidity in the early postoperative period and inferior long-term survival. Knowledge of the diagnosis preoperatively may facilitate management of patients.

Automated selection of myocardial inversion time with a convolutional neural network: Spatial temporal ensemble myocardium inversion network (STEMI-NET)

PURPOSE

Delayed enhancement imaging is an essential component of cardiac MRI, which is used widely for the evaluation of myocardial scar and viability. The selection of an optimal inversion time (TI) or null point (TINP ) to suppress the background myocardial signal is required. The purpose of this study was to assess the feasibility of automated selection of TINP using a convolutional neural network (CNN). We hypothesized that a CNN may use spatial and temporal imaging characteristics from an inversion-recovery scout to select TINP , without the aid of a human observer.

METHODS

We retrospectively collected 425 clinically acquired cardiac MRI exams performed at 1.5 T that included inversion-recovery scout acquisitions. We developed a VGG19 classifier ensembled with long short-term memory to identify the TINP . We compared the performance of the ensemble CNN in predicting TINP against ground truth, using linear regression analysis. Ground truth was defined as the expert physician annotation of the optimal TI. In a backtrack approach, saliency maps were generated to interpret the classification outcome and to increase the model's transparency.

RESULTS

Prediction of TINP from our ensemble VGG19 long short-term memory closely matched with expert annotation (ρ = 0.88). Ninety-four percent of the predicted TINP were within ±36 ms, and 83% were at or after expert TI selection.

CONCLUSION

In this study, we show that a CNN is capable of automated prediction of myocardial TI from an inversion-recovery experiment. Merging the spatial and temporal characteristics of the VGG-19 and long short-term-memory CNN structures appears to be sufficient to predict myocardial TI from TI scout.

Myocardial triglycerides in cardiac amyloidosis assessed by proton cardiovascular magnetic resonance spectroscopy

BACKGROUND

Cardiac involvement of amyloidosis leads to left-ventricular (LV) wall thickening with progressive heart failure requiring rehospitalization. Cardiovascular magnetic resonance (CMR) is a valuable tool to non-invasively assess myocardial thickening as well as structural changes. Proton CMR spectroscopy (1H-CMRS) additionally allows assessing metabolites including triglycerides (TG) and total creatine (CR). However, opposing results exist regarding utilization of these metabolites in LV hypertrophy or thickening. Therefore, the aim of this study was to measure metabolic alterations using 1H-CMRS in a group of patients with thickened myocardium caused by cardiac amyloidosis.

METHODS

1H-CMRS was performed on a 1.5 T system (Achieva, Philips Healthcare, Best, The Netherlands) using a 5-channel receive coil in 11 patients with cardiac amyloidosis (60.5 ± 11.4 years, 8 males) and 11 age- and gender-matched controls (63.2 ± 8.9 years, 8 males). After cardiac morphology and function assessment, proton spectra from the interventricular septum (IVS) were acquired using a double-triggered PRESS sequence. Post-processing was performed using a customized reconstruction pipeline based on ReconFrame (GyroTools LLC, Zurich, Switzerland). Spectra were fitted in jMRUI/AMARES and the ratios of triglyceride-to-water (TG/W) and total creatine-to-water (CR/W) were calculated.

RESULTS

Besides an increased LV mass and a thickened IVS concomitant to the disease characteristics, patients with cardiac amyloidosis presented with decreased global longitudinal (GLS) and circumferential (GCS) strain. LV ejection fraction was preserved relative to controls (60.0 ± 13.2 vs. 66.1 ± 4.3%, p = 0.17). Myocardial TG/W ratios were significantly decreased compared to controls (0.53 ± 0.23 vs. 0.80 ± 0.26%, p = 0.015). CR/W ratios did not show a difference between both groups, but a higher standard deviation in patients with cardiac amyloidosis was observed. Pearson correlation revealed a negative association between elevated LV mass and TG/W (R = - 0.59, p = 0.004) as well as GCS (R = - 0.48, p = 0.025).

CONCLUSIONS

A decrease in myocardial TG/W can be detected in patients with cardiac amyloidosis alongside impaired cardiac function with an association to the degree of myocardial thickening. Accordingly, 1H-CMRS may provide an additional diagnostic tool to gauge progression of cardiac amyloidosis along with standard imaging sequences.

TRIAL REGISTRATION

EK 2013-0132.

Myocardial nulling pattern in cardiac amyloidosis on time of inversion scout magnetic resonance imaging sequence - A new observation of temporal variability

Context:

The pattern of myocardial nulling in the inversion scout sequence [time of inversion scout (TIS)] of cardiac magnetic resonance imaging (MRI) is an accurate tool to detect cardiac amyloidosis. The pattern of nulling of myocardium and blood at varying times post gadolinium injection and its relationship with left ventricular mass (LVM) in amyloidosis have not been described previously.

Aims:

The aim is to study the nulling pattern of myocardium and blood at varying times in TIS and assess its relationship with LVM and late gadolinium enhancement (LGE) in amyloidosis.

Materials and Methods:

This was a retrospective study of 109 patients with clinical suspicion of cardiac amyloidosis who underwent MRI. Of these, 30 had MRI features of amyloidosis. The nulling pattern was assessed at 5 (TIS_5min) and 10 (TIS_10min) minutes (min) post contrast injection. Nulling pattern was also assessed at 3min (TIS_3min) in four patients and 7min (TIS_7min) in five patients. Myocardial mass index was calculated. Mann-Whitney U test was done to assess statistical difference in the myocardial mass index between patients with and without reversed nulling pattern (RNP) at TIS_5min.

Results:

RNP was observed in 58% at TIS_5min and 89.6% at TIS_10min. Myocardial mass index was significantly higher in patients with RNP at TIS_5min[mean = 94.87 g/m²; standard deviation (SD) =17.63) when compared with patients with normal pattern (mean = 77.61 g/m²; SD = 17.21) (U = 18; P = 0.0351).

Conclusion:

In cardiac amyloidosis, TIS sequence shows temporal variability in nulling pattern. Earlier onset of reverse nulling pattern shows a trend toward more LVM and possibly more severe amyloid load.

Myocardial native T2 measurement to differentiate light-chain and transthyretin cardiac amyloidosis and assess prognosis

BACKGROUND

To assess the diagnostic and prognosis value of myocardial native T2 measurement in the distinction between Light-chain (AL) and Transthyretin (ATTR) cardiac amyloidosis (CA).

METHODS

Forty-four patients with CA (24 AL; 20 ATTR) and 40 healthy subjects underwent 1.5 T cardiovascular magnetic resonance (CMR). They all underwent T1 and T2 mapping (modified Look-Locker inversion recovery), cine and late gadolinium enhancement (LGE) imaging. The Query Amyloid Late Enhancement (QALE) score, myocardial native T2, T1 and extra cellular volume fraction (ECV) were calculated for all patients.

RESULTS

Of the 44 patients, 36 (82%) exhibited enhancement on LGE images. Mean QALE score of AL (7.9 ± 6) and ATTR (10.5 ± 5) patients were similar (p = 0.6). Myocardial native T2 was significantly (p < 0.0001) higher in AL (63.2 ± 4.7 ms) than in ATTR (56.2 ± 3.1 ms) patients, and both higher (p < 0.001) than healthy subjects (51.1 ± 3.1 ms). Myocardial native T2 was highly correlated with myocardial native T1 (Spearman's rho = 0.79; p < 0.001) and exhibited higher diagnostic performance than T1 to separate AL and ATTR patients: the area under curve (AUC) of T2 was 0.94 (95% CI: 0.86-1, p < 0.001) and the AUC of T1 was 0.77 (95% CI: 0.62-0.91, p = 0.03). Myocardial native T2 did not impact overall survival in patients (HR 1.03 (0.94-1.12); p = 0.53) in contrast to ECV that was the best predictor of outcome (HR 1.66 per 0.1 increase in ECV (1.24-2.22); p = 0.0006).

CONCLUSIONS

Myocardial native T2 significantly is increased in CA, especially in AL patients in comparison to ATTR patients. Myocardial native T2 does not impact survival in CA patients in contrast to ECV that was the best predictor of outcome.

TRIAL REGISTRATION

Trial Registration and unique number: CNIL cardio 1778041. Date of registration: 20 December 2012.

Evaluation of Myocardial Strain in Patients With Amyloidosis Using Cardiac Magnetic Resonance Feature Tracking

PURPOSE

To study the use of cardiac magnetic resonance (CMR) feature tracking technique in evaluation of myocardial amyloidosis.

MATERIALS AND METHODS

CMR scans of 28 patients with biopsy proven myocardial amyloidosis and 35 controls were reviewed. Conventional short axis, vertical long axis, and 4-chamber cine steady-state free precession images from CMR scans were used to generate radial, circumferential, and longitudinal myocardial strain maps using feature tracking software. Global and regional peak radial, circumferential, and longitudinal strain values were computed.

RESULTS

There were significant decreases in radial, circumferential, and longitudinal strains in patients with myocardial amyloidosis globally and across layers (all P < 0.001). Strain was relatively preserved for the apex and most affected for the basal level. The area under the receiver operating characteristic curve for base peak radial, circumferential, and longitudinal strain 0.899, 0.884, and 0.866 and cut offs of 22.9, -13.3, and -10.9, respectively, were determined by receiver operating characteristic analysis. CMR feature tracking strain analysis of base-level strain parameters was able to differentiate patients with myocardial amyloidosis from those without myocardial amyloid with high sensitivity (82.5%) and specificity (82.9%) particularly for radial strain. The maximum sensitivity (89.3%) was achieved if any of the 3 parameters were abnormal, and the maximum specificity (88.6%) when all 3 parameters were abnormal.

CONCLUSION

Myocardial amyloidosis produces significant changes in regional and global strain parameters, and the peak radial and circumferential strain are the most affected at the basal layer.

Clinical and prognostic utility of cardiovascular magnetic resonance imaging in myeloma patients with suspected cardiac amyloidosis

OBJECTIVES

AL amyloidosis affects up to 30% of patients with multiple myeloma (MM), and cardiac involvement is associated with worse outcomes. Traditional screening modalities including EKG, echocardiography and biomarkers have limited value. The aim of this study was to evaluate the clinical and prognostic value of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) imaging in patients with plasma cell dyscrasias and suspected cardiac amyloidosis (CA).

METHODS

A total of 251 consecutive patients with plasma cell dyscrasias who underwent CMR were enrolled in this study. Primary endpoint was all cause mortality. Clinical, ECG, echocardiographic, biomarker and CMR predictors of mortality were analyzed.

RESULTS

Mean age of population was 63 ± 10 years, 36% females and 19% African Americans. During a median follow-up duration of 28 months (IQR 5-56), there were 97 deaths (39%). Patients who died were more likely to have diabetes (28% vs. 14%; P = 0.03), CAD (28% vs. 16%; P = 0.04) and CKD (33% vs. 21%; P = 0.04). With endomyocardial biopsy as the gold standard (42 (17%) patients), amyloid pattern on CMR (LGE+) had sensitivity and negative predictive values of 100%; specificity and positive predictive values of 80 and 81% with an AUC 0.9 for CA. History of CAD (HR 1.64, 95% CI 1.01-2.6; P = 0.04), brain natriuretic peptide (HR 1.0003 95% CI 1.0001-1.0006; P = 0.004) and LGE + (HR 1.72, 95% CI 1.05-2.8; P = 0.02) were independent predictors of mortality. LGE+ possessed incremental prognostic value over clinical, laboratory and echocardiographic variables for mortality prediction.

CONCLUSIONS

CMR is a clinically useful tool for diagnosis and prognostication in myeloma patients with suspected CA.

Isolated Tricuspid Regurgitation: Initial Manifestation of Cardiac Amyloidosis

Amyloid deposits in the heart are not exceptional in systemic amyloidosis. The clinical manifestations of cardiac amyloidosis may include restrictive cardiomyopathy, characterized by progressive diastolic and eventually systolic bi-ventricular dysfunction; arrhythmia; and conduction defects. To the best of our knowledge, no previous cases of isolated tricuspid regurgitation as the initial manifestation of cardiac amyloidosis have been reported. We describe a rare case of cardiac amyloidosis that initially presented with severe tricuspid regurgitation in a 42-year-old woman who was successfully treated with tricuspid valve replacement. Unusual surgical findings prompted additional evaluation that established a diagnosis of plasma cell myeloma.

Noninvasive Identification of ATTRwt Cardiac Amyloid: The Re-emergence of Nuclear Cardiology

More than half of all subjects with chronic heart failure are older adults with preserved ejection fraction (HFpEF). Effective therapy for this condition is yet to be delineated by clinical trials, suggesting that a greater understanding of underlying biologic mechanisms is needed, especially for the purpose of clinical intervention and future clinical trials. Amyloid infiltration of the myocardium is an underappreciated contributing factor to HFpEF that is often caused by misfolded monomers or oligomers of the protein transthyretin. While previously called senile cardiac amyloidosis and traditionally requiring endomyocardial biopsy for diagnosis, advances in our pathophysiologic understanding of this condition, coupled with nuclear imaging techniques using bone isotopes that can diagnose this condition noninvasively and the development of potential therapies, have resulted in a renewed interest in this previously considered "rare" condition. This reviewer focuses on the re-emergence of nuclear cardiology using pyrophosphate agents that hold promise for early, noninvasive identification of affected individuals.

Myocardial tissue characterization with magnetic resonance imaging

The availability of an accurate, noninvasive method using cardiac magnetic resonance imaging (MRI) to distinguish microscopic myocardial tissue changes at a macroscopic scale is well established. High-resolution in vivo monitoring of different pathologic tissue changes in the heart is a useful clinical tool for assessing the nature and extent of cardiac pathology. Cardiac MRI utilizes myocardial signal characteristics based on relaxation parameters such as T1, T2, and T2 star values. Identifying changes in relaxation time enables the detection of distinctive myocardial diseases such as cardiomyopathies and ischemic myocardial injury. The presented state-of-the-art review paper serves the purpose of introducing and summarizing MRI capability of tissue characterization in present clinical practice.

Late gadolinium enhancement in cardiac amyloidosis: attributable both to interstitial amyloid deposition and subendocardial fibrosis caused by ischemia

Gadolinium contrast agents used for late gadolinium enhancement (LGE) distribute in the extracellular space. Global diffuse myocardial LGE pronounced in the subendocardial layers is common in cardiac amyloidosis. However, the pathophysiological basis of these findings has not been sufficiently explained. A 64-year-old man was admitted to our hospital with leg edema and nocturnal dyspnea. Bence Jones protein was positive in the urine, and an endomyocardial and skin biopsy showed light-chain (AL) amyloidosis. He died of ventricular fibrillation 3 months later. 9 days before death, the patient was examined by cardiac magnetic resonance (CMR) imaging on a 3-T system. We acquired LGE data at 2, 5, 10, and 20 min after the injection of gadolinium contrast agents, with a fixed inversion time of 350 ms. Myocardial LGE developed sequentially. The myocardium was diffusely enhanced at 2 min, except for the subendocardium, but LGE had extended to almost the entire left ventricle at 5 min and predominantly localized to the subendocardial region at 10 and 20 min. An autopsy revealed massive and diffused amyloid deposits in perimyocytes throughout the myocardium. Old and recent ischemic findings, such as replacement fibrosis and coagulative myocyte necrosis, were evident in the subendocardium. In the intramural coronary arteries, mild amyloid deposits were present within the subepicardial to the mid layer of the left ventricle, but no stenotic lesions were evident. However, capillaries were obstructed by amyloid deposits in the subendocardium. In conclusion, the late phase of dynamic LGE (at 10 and 20 min) visualized in the subendocardium corresponded to the interstitial amyloid deposition and subendocardial fibrosis caused by ischemia in our patient.

CT and MRI evaluation of cardiac complications in patients with hematologic diseases: a pictorial review

Cardiac complications with hematologic diseases are not uncommon but it is difficult to diagnose, due to non-specific clinical symptoms. Prompt recognition of these potentially fatal complications by cardiac computed tomography (CT) or cardiac magnetic resonance imaging (MRI) may help to direct clinicians to specific treatments according to causes. Thrombosis is often related to central venous catheter use and is usually located at the catheter tip near the atrial wall. Differentiation of thrombosis from normal structure is possible with CT and, distinction of a thrombus from a tumor is possible on a delayed enhancement MRI with a long inversion time (500-600 ms). Granulocytic sarcoma of the heart is indicated by an infiltrative nature with involvement of whole layers of myocardium on CT and MRI. MRI with T2* mapping is useful in evaluating myocardial iron content in patients with hemochromatosis. Diffuse subendocardial enhancement is typically observed on delayed MRIs in patients with cardiac amyloidosis. T1 mapping is an emerging tool to diagnose amyloidosis. Myocardial abscess can occur due to an immunocompromised status. CT and MRI show loculated lesions with fluid density and concomitant rim-like contrast enhancement. Awareness of CT and MRI findings of cardiac complications of hematologic diseases can be helpful to physicians for clinical decision making and treatment.

Comparison of different types of cardiac amyloidosis by cardiac magnetic resonance imaging

OBJECTIVES

We sought to determine cardiac morphological and functional differences between light-chain (AL), mutant-type transthyretin (ATTRmt) and wild-type TTR (ATTRwt) amyloidosis using contrast-enhancement cardiac magnetic resonance imaging (CE-CMR). Finally, we attempted to establish the diagnostic and prognostic impact of these findings.

INTRODUCTION

The most common forms of cardiac amyloid are AL and ATTR amyloidosis, but the clinical courses of these variants are quite heterogeneous. While CE-CMR is used to evaluate patients with cardiac amyloidosis, its ability to predict prognosis in these patients is debatable.

METHODS

About 130 patients with cardiac amyloidosis (AL, n = 62; ATTRmt, n = 30, ATTRwt, n = 33) were assessed by CE-CMR (cardiac morphology, cardiac function, late gadolinium enhancement).

RESULTS

Left ventricular (LV) mass, basal and mid-ventricular maximal wall thickness, and thickness of the inter-atrial septum were higher in ATTRwt when compared to AL and ATTRmt amyloidosis. Tricuspid annular excursion was lower in ATTRwt amyloidosis than in AL amyloidosis. CE was observed in 94.6% of the patients (AL 80.6%; ATTRmt 90%; ATTRwt 87.9%) with significant differences in quality and intensity between the groups. Differentiation of amyloid types was achieved by combination of age, number of organs, the presence of inferolateral CE-CMR, thickness of inter-atrial septum and troponin T. Overall 1-year-survival rates were 93.3, 93.9 and 70.5% in ATTRwt, ATTRmt and AL amyloidosis, respectively. LV mass, mitral annular excursion and NT-proBNP in AL amyloidosis, LV mass maximal apical wall thickness and troponin T in ATTRwt amyloidosis, and finally NT-proBNP and renal function in ATTRmt amyloidosis were independent predictors of outcome.

CONCLUSIONS

This study demonstrates that CE-CMR can highlight morphological and functional differences between different types of cardiac amyloidosis. In addition, CE-CMR and cardiac biomarkers provide useful prognostic information in patients with cardiac amyloidosis.

Recent advances in the diagnosis and management of cardiac amyloidosis

The heart is commonly involved in various forms of amyloidosis and cardiomyopathy is a major cause of morbidity and mortality in these patients. Diagnosis of cardiac amyloidosis is often delayed due to nonspecific presenting symptoms and failure to recognize early signs of amyloid heart disease on routine cardiac imaging. Treatment of cardiac amyloidosis depends upon the type of amyloid protein. Systemic chemotherapy with or without stem cell transplantation is used to treat immunoglobulin-related amyloidosis and liver transplantation is used for familial transthyretin amyloidosis in select patients. Clinical trials with siRNA for the treatment of transthyretin amyloid cardiomyopathies and amyloid protein stabilizers are ongoing. Prognosis depends on the type of amyloid protein with poorer outcomes noted in immunoglobulin light-chain amyloidosis. Supportive care forms the cornerstone of management and advancements in cardiac imaging and proteomics are expected to positively impact our ability to diagnose, prognosticate and treat cardiac amyloidosis.

Isolated heart transplantation for familial transthyretin (TTR) V122I cardiac amyloidosis

Transthyretin (TTR) cardiac amyloidosis is characterized by deposition of either mutant or wild type TTR amyloid protein in the myocardium ultimately leading to progressive cardiomyopathy and heart failure. The most common TTR gene mutation that leads to TTR cardiac amyloidosis is the valine-to-isoleucine substitution at position 122 (V122I or Ile122). Currently, the only definitive treatment suggested for mutant TTR cardiac amyloidosis is the combined or sequential liver-heart transplantation in eligible patients, since liver is the source of TTR production. Here, we report a case of heterozygous Val122L mutated TTR-related cardiac amyloidosis treated with isolated heart transplantation with no recurrence of amyloid in the cardiac allograft and no systemic abnormalities 5 years after heart transplantation. Abbreviations MMF mycophenolate mofetil NYHA New York Heart Association TTR transthyretin VE minute ventilation.

Cardiac magnetic resonance imaging of systemic amyloidosis patients with normal left ventricular ejection fraction: An initial study

Objective: The purpose of this study was to find whether Cardiac Magnetic Resonance (CMR) could assess the myocardial interstitium in patients suffering from systemic amyloidosis with normal left ventricular ejection fraction.

Methods: Twenty Six patients in whom systemic amyloidosis was confirmed by kidney biopsy were investigated. Five patients with normal left ventricular ejection fraction were selected. The heart function of the patients was diagnosed by two-dimensional transthoracic echocardiography. The main MR sequences include an inversion recovery prepared echo planar imaging perfusion sequence, inversion recovery TrueFISP sequence (delayed enhancement) and TrueFISP cine sequence for heart function measurement (including ejection fraction (EF), end diastolic volume (EDV), end systolic volume (ESV), stroke volume (SV) and cardiac output (CO)).

Results: Perfusion defects were seen in three patients. In these patients, myocardial enhancement was visible on late gadolinium enhancement images. The enhancement pattern was diffuse in three patients and focal in two patients. Heart dysfunction was mild, as follows: EF normal (range, 56-75%; mean, 69.4%), ESV normal (range, 15.7-30.0; mean, 23.0), EDV decreased (range, 42.1-96.6; mean, 72.7), SV decreased (range, 23.7-68.6; mean, 49.6) and CO normal (range, 2.6-5.9; mean, 3.9). Hematoxylin and eosin stain and Congo red stain demonstrated typical amyloid deposits. Amyloidosis was classified as amyloid light chain by kappa and lambda stain.

Conclusions: Cardiac Magnetic Resonance could detect abnormal myocardial interstitium in systemic amyloidosis patients with normal left ventricular ejection fraction.

CMR imaging with rapid visual T1 assessment predicts mortality in patients suspected of cardiac amyloidosis

OBJECTIVES

This study tested the diagnostic and prognostic utility of a rapid, visual T1 assessment method for identification of cardiac amyloidosis (CA) in a "real-life" referral population undergoing cardiac magnetic resonance for suspected CA.

BACKGROUND

In patients with confirmed CA, delayed-enhancement cardiac magnetic resonance (DE-CMR) frequently shows a diffuse, global hyperenhancement (HE) pattern. However, imaging is often technically challenging, and the prognostic significance of diffuse HE is unclear.

METHODS

Ninety consecutive patients referred for suspected CA and 64 hypertensive patients with left ventricular hypertrophy (LVH) were prospectively enrolled and underwent a modified DE-CMR protocol. After gadolinium administration a method for rapid, visual T1 assessment was used to identify the presence of diffuse HE during the scan, allowing immediate optimization of settings for the conventional DE-CMR that followed. The primary endpoint was all-cause mortality.

RESULTS

Among patients with suspected CA, 66% (59 of 90) demonstrated HE, with 81% (48 of 59) of these meeting pre-specified visual T1 assessment criteria for diffuse HE. Among hypertensive LVH patients, 6% (4 of 64) had HE, with none having diffuse HE. During 29 months of follow-up (interquartile range: 12 to 44 months), there were 50 (56%) deaths in patients with suspected CA and 4 (6%) in patients with hypertensive LVH. Multivariable analysis demonstrated that the presence of diffuse HE was the most important predictor of death in the group with suspected CA (hazard ratio: 5.5, 95% confidence interval: 2.7 to 11.0; p < 0.0001) and in the population as a whole (hazard ratio: 6.0, 95% confidence interval 3.0 to 12.1; p < 0.0001). Among 25 patients with myocardial histology obtained during follow-up, the sensitivity, specificity, and accuracy of diffuse HE in the diagnosis of CA were 93%, 70%, and 84%, respectively.

CONCLUSIONS

Among patients suspected of CA, the presence of diffuse HE by visual T1 assessment accurately identifies patients with histologically-proven CA and is a strong predictor of mortality.

Current state of cardiac amyloidosis

PURPOSE OF REVIEW

Cardiac amyloidosis, an infiltrative restrictive cardiomyopathy once thought to be universally fatal, is now increasingly recognized as less rare than previously thought. This update is intended to provide a review of newer aspects of the presentation, diagnosis and treatment of cardiac amyloidosis.

RECENT FINDINGS

Amyloid involvement of the heart is increasingly seen, especially in the elderly population. Recent data suggest life expectancy has increased from 6 to 16-20 months in the most common subtype, AL amyloid. The clinical presentation is typically one of heart failure in the setting of normal or low normal ejection fraction, inappropriate ventricular hypertrophy and atrial enlargement with or without atrial fibrillation. Diagnosis is now most often made by cardiac MRI, with 2D echocardiography serving more of a screening role in patients with heart failure or a similar family history. The gold standard diagnostic test is right-ventricular biopsy, which demonstrates positivity for Congo Red staining. Due to a propensity for disease progression, typically low systemic blood pressure, frequent extra-cardiac involvement and autonomic dysfunction, cardiac amyloidosis is difficult to treat due to poor tolerance of most cardiovascular medication and poor outcome for transplantation. Newer therapies such as bortezomib, usually given to patients with multiple myeloma and serum light chains, are promising in controlling amyloidosis.

CONCLUSION

Recent advances in diagnosis and treatment of amyloid are associated with improved prognosis. Newer therapies offer future benefits.

Comparison between (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement in evaluating cardiac involvement in patients with transthyretin familial amyloid polyneuropathy

OBJECTIVE

Cardiac involvement is not rare in systemic amyloidosis and is associated with poor prognosis. Both (99m)Tc-diphosphonate imaging and cardiac MRI with late gadolinium enhancement are considered valuable tools in revealing amyloid deposition in the myocardium; however, to our knowledge, no comparative study between the two techniques exists. We compared findings of these two techniques in patients with transthyretin-familial amyloid polyneuropathy (FAP).

SUBJECTS AND METHODS

Eighteen patients with transthyretin-FAP underwent (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement. Images were visually evaluated by independent readers to determine the presence of radiotracer accumulation or late gadolinium enhancement-positive areas at the level of cardiac chambers.

RESULTS

Interobserver agreement ranged from moderate to very good for (99m)Tc-diphosphonate imaging findings and was very good for findings of MRI with late gadolinium enhancement. Left ventricle (LV) radiotracer uptake was found in 10 of 18 patients, whereas LV late gadolinium enhancement-positive areas were found in eight of 18 patients (χ(2) = 0.9; p = 0.343). One hundred fifty-nine LV segments showed (99m)Tc-diphosphonate accumulation, and 57 LV segments were late gadolinium enhancement positive (p < 0.0001). Radiotracer uptake was found in the right ventricle (RV) in eight patients and in both atria in five patients, whereas MRI showed that RV was involved in three patients and both atria in six patients; the differences were not statistically significant (RV, p = 0.07; atria, p = 1). Intermodality agreement between (99m)Tc-diphosphonate imaging and MRI ranged from fair to good.

CONCLUSION

Our study shows that, although (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement have similar capabilities to identify patients with myocardial amyloid deposition, cardiac amyloid infiltration burden can be significantly underestimated by visual analysis of MRI with late gadolinium enhancement compared with (99m)Tc-diphosphonate imaging.

Radiology and pathology correlation in common infiltrative cardiomyopathies

Infiltrative cardiomyopathies generally pose a diagnostic dilemma as current diagnostic tools are imprecise. Invasive endomyocardial biopsy is considered as the gold standard however it has some limitations. Recently cardiovascular magnetic resonance (CMR) is emerging as an excellent technique in diagnosing infiltrative cardiomyopathies and is increasingly being used. Characteristic pathologic and radiologic findings in most common infiltrative cardiomyopathies (amyloid, sarcoid and Fabry's) are discussed and correlated with relative CMR and histologic examples. There is fairly good correlation between the non-invasive radiologic and the invasive histologic findings in common infiltrative cardiomyopathies. Non-invasive CMR with its high sensitivity and specificity has an excellent role in establishing the diagnosis and improving the prognosis of common infiltrative cardiomyopathies.

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.

Utility of the inversion scout sequence (TI scout) in diagnosing myocardial amyloid infiltration

To evaluate the utility of inversion scout (TI-scout) obtained during cardiac magnetic resonance imaging (CMR) in diagnosing myocardial amyloid infiltration. A retrospective analysis of CMR exams in 39 patients (24 males, age range 29-77 years) was performed. Imaging was performed on a 1.5T system, and included steady state cine, post contrast TI-scout and delayed enhancement images. Evaluations included studies in 13 patients with myocardial amyloidosis and 26 patients without myocardial amyloidosis. To characterize abnormal nulling, the time to myocardial nulling on the TI scout was compared to the null times of the blood pool and spleen for each scan. The sensitivity and specificity of different tissue nulling abnormalities for myocardial amyloidosis were computed. The null times of tissues in 18/26 (69%) patients in the non-amyloid group followed a consistent order with the blood pool null time preceding the myocardial nulling which was equal to that of splenic nulling (Type 1 pattern). This order differed in all 13 patients with myocardial amyloidosis described as three non-mutually exclusive nulling categories: 10 patients had myocardial null time preceding or coincident with blood pool (Type 2 pattern); in 11 patients myocardial null time was non-coincident with splenic nulling (Type 3 pattern); and in 8 patients myocardial null time was non-coincident with both blood pool AND splenic nulling (Type 4 pattern). While no patient exhibited Type 4 nulling pattern in the non-amyloid group, 1/26 patient had a Type 2 and 7/26 patients had a Type 3 nulling pattern. A sensitivity of 100% was obtained when either Type 2 OR Type 3 nulling was present while a specificity of 100% was obtained when both Type 2 AND Type 3 nulling were present together (Type 4 pattern). Our study demonstrates that the pattern of nulling on the TI scout sequence CMR has potential diagnostic utility for the presence of myocardial amyloidosis. The temporal pattern of myocardial, blood pool and splenic nulling needs to be carefully evaluated on the TI scout sequence and could prove useful in other infiltrative cardiomyopathies.

Cardiac MR imaging of nonischemic cardiomyopathies: imaging protocols and spectra of appearances

Recent technologic advances in cardiac magnetic resonance (MR) imaging have resulted in images with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MR is a valuable imaging technique for detection and assessment of the morphology and functional characteristics of the nonischemic cardiomyopathy. It has gained acceptance as a standalone imaging modality that can provide further information beyond the capabilities of traditional modalities such as echocardiography and angiography. Black-blood fast spin-echo MR images allow morphologic assessment of the heart with high spatial resolution, while T2-weighted MR images can depict acute myocardial edema. Contrast material-enhanced images can depict and be used to quantify myocardial edema, infiltration, and fibrosis. This review presents recommended cardiac MR protocols for and the spectrum of imaging appearances of the nonischemic cardiomyopathies.

Prognostic impact of T2-weighted CMR imaging for cardiac amyloidosis

OBJECTIVES

Using cardiac magnetic resonance imaging (MRI) we tested the diagnostic value of various markers for amyloid infiltration.

METHODS

We performed MRI at 1.5 T in 36 consecutive patients with cardiac amyloidosis and 48 healthy volunteers. The protocol included cine imaging, T2-weighted spin echo, T1-weighted spin echo before and early after contrast and late gadolinium enhancement. We compared the frequency of abnormalities and their relation to mortality.

RESULTS

Median follow-up was 31 months. Twenty-three patients died. Mean left ventricular (LV) mass was 205 ± 70 g. LV ejection fraction (EF) was 55 ± 12%. T2 ratio was 1.5 ± 0.4. 33/36 patients had pericardial and 22/36 had pleural effusions. All but two had heterogeneous late enhancement. Surviving patients did not differ from those who had died with regard to gender, LV mass or volume. Surviving patients had a significantly higher LVEF (60.4 ± 9.9% vs. 51.6 ± 11.5%; p = 0.03). The deceased patients had a lower T2 ratio than those who survived (1.38 ± 0.42 vs. 1.76 ± 0.17; p = 0.005). Low T2 was associated with shorter survival (Chi-squared 11.3; p < 0.001). Cox regression analysis confirmed T2 ratio < 1.5 as the only independent predictors for survival.

CONCLUSION

Cardiac amyloidosis is associated with hypointense signal on T2-weighted images. A lower T2 ratio was independently associated with shortened survival.

MRI of cardiac involvement in transthyretin familial amyloid polyneuropathy

OBJECTIVE

The purpose of this study was to evaluate cardiac MRI features in a group of patients with transthyretin familial amyloid polyneuropathy (FAP).

SUBJECTS AND METHODS

Sixteen patients with transthyretin FAP underwent 2D echocardiography with Doppler examination, cardiac MRI, and (99m)Tc-diphosphonate (DPD) scintigraphy. Four patients had peripheral polyneuropathy, three had carpal tunnel syndrome, one patient had symptoms and signs of heart failure, and eight patients had no symptoms but had a family history of FAP. At MRI, cardiac function parameters and delayed contrast enhancement findings were evaluated.

RESULTS

Six patients had cardiac radiotracer uptake at scintigraphy (FAP cardiac group), and 10 patients had no cardiac uptake (FAP noncardiac group). The FAP cardiac group included the four patients with peripheral neuropathy, one patient with carpal tunnel syndrome, and the only patient with heart failure. At MRI, abnormal contrast enhancement was found in all patients with positive scintigraphic findings and in no patient with negative scintigraphic findings. All patients had involvement of the left ventricle and other chambers or structures (atria, right ventricle, tricuspid valve leaflets). Left ventricular contrast enhancement was focal in four patients, subendocardial circumferential in one patient, and diffuse in one patient. The only patient with signs of heart failure had circumferential subendocardial enhancement.

CONCLUSION

Cardiac contrast-enhanced MRI can be used to identify cardiac amyloidosis in patients with FAP who do not have clinical signs of heart involvement. In these patients, the typical subendocardial circumferential pattern of contrast enhancement is rare. We observed unusual enhancement patterns as focal or diffuse left ventricular enhancement accompanied by enhancement of the atria, tricuspid valve, or right ventricle.

Uncharted waters: rare and unclassified cardiomyopathies characterized on cardiac magnetic resonance imaging

Cardiac magnetic resonance imaging (CMR) has undergone considerable technology advances in recent years, so that it is now entering into mainstream cardiac imaging practice. In particular, CMR is proving to be a valuable imaging tool in the detection, morphological assessment and functional assessment of cardiomyopathies. Although our understanding of this broad group of heart disorders continues to expand, it is an evolving group of entities, with the rarer cardiomyopathies remaining poorly understood or even unclassified. In this review, we describe the clinical and pathophysiological aspects of several of the rare/unclassified cardiomyopathies and their appearance on CMR.

Prognosis assessment of cardiac involvement in systemic AL amyloidosis by magnetic resonance imaging

BACKGROUND

Cardiac involvement is one of the most important prognostic factors in systemic AL amyloidosis. The aim of our study was to assess the role of cardiovascular magnetic resonance (CMR) imaging in prognosis evaluation in AL amyloidosis.

METHODS

We retrospectively analyzed 29 consecutive patients with AL amyloidosis who had undergone CMR. Clinical, laboratory, echocardiographic, and CMR characteristics were compared between CMR-positive (ie, with CMR signs of cardiac localization of AL amyloidosis) and CMR-negative patients. Univariate and multivariate analyses were performed to assess the prognostic value of positive CMR in comparison with other prognostic factors.

RESULTS

CMR was positive in 11 patients (38%). The overall survival rates for CMR-positive patients were 28%, 14%, and 14% versus 84%, 77%, and 45% at 1, 2, and 5 years, respectively, for CMR-negative patients (P=.002). Late gadolinium enhancement patterns, biventricular hypertrophy, and pericardial effusion on CMR were more frequent in nonsurvivors. Congestive heart failure, abnormal echocardiography, Eastern Cooperative Oncology Group grade >1, brain natriuretic peptide, and left ventricular ejection fraction <55% also were associated with a decreased survival. The presence of congestive heart failure was the only significant variable associated with survival on multivariate analysis.

CONCLUSION

We found that the presence of a positive CMR in AL amyloidosis was associated with a significantly increased risk of death, in particular of cardiac origin, but was not independent of clinical congestive heart failure.

Noninvasive diagnosis of cardiac amyloidosis by MRI and echochardiography

This study described the radiological features on echocardiography and MRI specific to cardiac amyloidosis confirmed on biopsy. Eleven cases of biopsy-proven cardiac amyloidosis were retrospectively reviewed in this study. All patients underwent biopsy, cardiac MRI and echocardiography. The main echocardiography and MRI findings were as follows: diffuse ventricular and septum wall thickening, atrial enlargement, pericardial effusion, restricted left ventricular (LV) systolic and diastolic function, characteristic granular sparkling of myocardium. MRI revealed a characteristic pattern of global subendocardial late enhancement, extending in varying degrees into the neighboring myocardium. The findings agreed with the infiltration distribution of amyloid protein. Typical abnormalities seen on echocardiography and MRI should have important diagnostic and prognostic value of cardiac amyloidosis. MRI should be considered in the diagnosis of cardiac amyloidosis if echocardiographic features are suspicious.

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.

Serum levels of NT-proBNP as surrogate for cardiac amyloid burden: new evidence from gadolinium-enhanced cardiac magnetic resonance imaging in patients with amyloidosis

BACKGROUND

The prognostic value of NT-proBNP has been recognized in patients with amyloidosis complicated by cardiac involvement. We aimed to use contrast enhanced cardiac magnetic resonance imaging (CMR) to identify functional and structural alterations related to levels of NT-proBNP better to understand the mechanisms of its release in cardiac amyloidosis.

METHODS AND RESULTS

CMR was performed on a 1.5-T scanner in 34 patients with biopsy proven amyloid light chain (AL; n = 27) or hereditary transthyretin related (TTR; n = 7) amyloidosis. NT-proBNP was higher in patients with (n = 25) compared to patients without cardiac involvement (n = 9) (2931 (IQR: 972-8629; min-max: 25-27,277) pg/ml vs. 177 (IQR: 71-1431; min-max: 22-7935) pg/ml, p = 0.008). ROC analysis identified a NT-proBNP of <2426.5 pg/ml as optimal discriminator for event free survival (682 +/- 65 days). NT-proBNP did not correlate with LV- ejection fraction, end-diastolic and end-systolic volumes or stroke volume. There was a moderate correlation between NT-proBNP and LV-mass (R = 0.52, p = 0.003) and extent of late gadolinium enhancement (LGE; R = 0.41, p = 0.04).

CONCLUSIONS

This study confirms the prognostic value of NT-proBNP in patients with AL and TTR amyloidosis and provides the novel finding that NT-proBNP correlates with surrogates of myocardial amyloid burden such as LV-mass and LGE, supporting the concept of NT-proBNP as a biomarker reflecting the severity of cardiac amyloid infiltration.

Diagnostic and prognostic utility of cardiovascular magnetic resonance imaging in light-chain cardiac amyloidosis

Although the presence of abnormal late gadolinium enhancement (LGE) in cardiac amyloidosis has been well established, its prognostic implication and utility to identify cardiac involvement in patients with systemic amyloidosis is unknown. The aim of this study was to assess the diagnostic and prognostic significance of cardiovascular magnetic resonance imaging in patients with amyloid light-chain amyloidosis but unknown cardiac involvement. Cardiovascular magnetic resonance imaging with LGE was performed in 28 patients with systemic amyloidosis. The presence of cardiac amyloidosis was determined by separate clinical evaluation. The performance of LGE for the prediction of cardiac amyloidosis and prognostic implications of LGE were determined. LGE was observed in 19 patients (68%). The sensitivity, specificity, positive predictive value, and negative predictive value of LGE for the identification of clinical cardiac involvement were 86%, 86%, 95%, and 67%, respectively. During a median follow-up period of 29 months, there were 5 deaths (82% survival). LGE itself did not predict survival (p = 0.62). LGE volume was positively correlated with serum level of B-type natriuretic peptide (BNP; R = 0.64, p < or =0.001), and in multivariate analysis, LGE volume proved the strongest independent predictor of BNP. BNP was correlated with New York Heart Association class (p = 0.03). Reduced right ventricular end-diastolic volume (p <0.01) and stroke volume (p = 0.02) were associated with mortality. In conclusion, in patients with systemic amyloidosis, LGE is highly sensitive and specific for the identification of cardiac involvement but does not predict survival. LGE is strongly correlated with heart failure severity as assessed by BNP.