Prognostic Significance of Cardiac Magnetic Resonance Imaging Late Gadolinium Enhancement in Fabry Disease

Cardiac Magnetic Resonance Imaging T1 and T2 Mapping in Systemic Lupus Erythematosus in Relation to Antimalarial Treatment

PURPOSE

Patients with systemic lupus erythematosus (SLE) are at risk of cardiac disease including antimalarial-induced cardiomyopathy (AMIC). The purpose of this study is to evaluate cardiac magnetic resonance imaging parametric mapping findings in SLE patients with AMIC and investigate the relationship of T1/T2 mapping to antimalarial (AM) treatment duration.

MATERIALS AND METHODS

All patients with SLE who had undergone cardiac magnetic resonance imaging with T1/T2 mapping for evaluation of suspected cardiac disease between 2018 and 2021 were evaluated and compared with healthy controls. To facilitate comparison between scanners, T1/T2 values were converted to a z -score using scanner-specific local reference values. Patients were classified into 3 groups: AMIC, myocarditis, and other (no AMIC or myocarditis).

RESULTS

Forty-five SLE patients (47±17 y, 80% female; 8 [18%] with AMIC and 7 [16%] with myocarditis) and 30 healthy controls (39±15 y, 60% female) were included. Patients with AMIC had higher T1 and T2 compared with controls ( z -score 1.1±1.3 vs. 0±0.6, P =0.01 and 1.7±1.1 vs. 0±1.0, P <0.01, respectively) and lower values compared with those with myocarditis (3.7±1.6, P <0.01 and 4.0±2.0, P <0.01, respectively). T1 correlated negatively with AM treatment duration in patients without AMIC or myocarditis ( r =-0.36, P =0.048) and positively in patients with AMIC ( r =0.92, P =0.001). AM treatment duration did not correlate significantly with T1 in patients with myocarditis or with T2 in any group.

CONCLUSIONS

The relationship between T1 and AM treatment duration differed between groups. Native T1 decreases with longer treatment in patients without AMIC or myocarditis, possibility due to glycosphingolipid accumulation. In patients with AMIC, increasing T1 with longer treatment could reflect fibrosis.

Fabry Disease and Its Management: A Literature Analysis

A review was conducted to evaluate interventional therapy for Fabry disease. Fabry disease is a multisystemic X-linked storage disorder that affects the entire body and needs to be treated at an early age. The search was conducted using keywords such as "Fabry disease" and "Management" to review the databases. Seven studies were chosen from the 90 studies, and it was discovered that migalastat and enzyme replacement medication were successful in treating the condition, whereas agalsidase beta failed to have a positive effect on the patient. However, this analysis produced ambiguous conclusions. As only a small number of studies were included in the analysis, additional investigations and evaluations based on randomized controlled trials and case studies are required to determine potential drug-related outcomes. There is a need for future therapeutic research to cure genetically affected illnesses and diseases such as Fabry disease.

Cardiac MRI of Hereditary Cardiomyopathy

Hereditary cardiomyopathy comprises a heterogeneous group of diseases of the cardiac muscle that are characterized by the presence of genetic mutations. Cardiac MRI is central to evaluation of patients with cardiomyopathy owing to its ability to allow evaluation of many different tissue properties in a single examination. For example, cine MRI is the standard of care for assessment of myocardial structure and function. It clearly shows regions of asymmetric wall thickening that are typical of hypertrophic cardiomyopathy and allows it to be differentiated from other hereditary disorders such as Fabry disease or transthyretin cardiac amyloidosis that produce concentric hypertrophy. Late gadolinium enhancement provides a different tissue property and allows these latter two causes of concentric hypertrophy to be distinguished on the basis of their enhancement appearances (Fabry disease shows midwall basal inferolateral enhancement, and amyloidosis shows global subendocardial enhancement). Native T1 mapping may similarly allow differentiation between Fabry disease and amyloidosis without the use of contrast material. T2*-weighted MRI is important in the detection and quantification of iron overload cardiomyopathy. Other hereditary entities for which comprehensive MRI has proven essential include Danon disease, familial dilated cardiomyopathy, hereditary muscular dystrophy, arrhythmogenic right ventricular cardiomyopathy, and ventricular noncompaction. As a result of the diagnostic power of cardiac MRI, cardiac MRI examinations are being requested with increasing frequency, not only in academic centers but also in community practices. The genetic background, pathophysiologic characteristics, and clinical presentation of patients with hereditary cardiomyopathy are described; the characteristic cardiac MRI features of hereditary cardiomyopathy are discussed; and the role of MRI in risk stratification, treatment, and prognostication in patients with cardiomyopathy is reviewed. ^©RSNA, 2022 Online supplemental material is available for this article.

Fabry disease - current data and therapeutic approaches

Fabry disease represents an X-linked inherited disorder resulting in the accumulation of globotriaosylceramide (Gb3). This review explains the clinical manifestations and the possible therapies for this condition. Fabry disease is considered the second most frequent lysosomal storage disease. More than 1000 mutations of the galactosidase alpha (GLA) gene associated with this disorder have been identified. Pain, either episodic crises or chronic pain, is one of the earliest symptoms in Fabry disease. Gastrointestinal, ocular, ear or skeletal manifestations may complete the clinical picture. Cardiac and renal involvements are the most severe complications leading to organ failure and death. The cerebrovascular lesions may result in severe symptoms including stroke at younger ages. The diagnosis of Fabry disease may be put by enzymatic assays of the α-galactosidase A (AGAL-A) activity in plasma or leukocytes but genetic analysis remains the “gold standard” in identifying the precise mutation and even guiding the treatment. Enzyme replacement therapy (ERT) was the first step in treating subjects with Fabry disease. It proved important decrease of the number of sever clinical events and reduction of symptoms. Chemical chaperone therapy has many advantages including oral administration and was already approved in Europe and US, but it is suitable only for subjects with amenable mutations. Gene therapies (either ex vivo or in vivo) promise to represent a new era for many disorders including Fabry disease, the preliminary data being encouraging. Although many steps were taken in understanding the pathogeny of Fabry disease, future research is needed especially in the field of therapeutic approaches.

Noninvasive rapid cardiac magnetic resonance for the assessment of cardiomyopathies in low-middle income countries

Introduction: Cardiac Magnetic Resonance (CMR) is a crucial diagnostic imaging test that redefines diagnosis and enables targeted therapies, but the access to CMR is limited in low-middle Income Countries (LMICs) even though cardiovascular disease is an emergent primary cause of mortality in LMICs. New abbreviated CMR protocols can be less expensive, faster, whilst maintaining accuracy, potentially leading to a higher utilization in LMICs.Areas covered: This article will review cardiovascular disease in LMICs and the current role of CMR in cardiac diagnosis and enable targeted therapy, discussing the main obstacles to prevent the adoption of CMR in LMICs. We will then review the potential utility of abbreviated, cost-effective CMR protocols to improve cardiac diagnosis and care, the clinical indications of the exam, current evidence and future directions.Expert opinion: Rapid CMR protocols, provided that they are utilized in potentially high yield cases, could reduce cost and increase effectiveness. The adoption of these protocols, their integration into care pathways, and prioritizing key treatable diagnoses can potentially improve patient care. Several LMIC countries are now pioneering these approaches and the application of rapid CMR protocols appears to have a bright future if delivered effectively.

Quantification of myocardial deformation in patients with Fabry disease by cardiovascular magnetic resonance feature tracking imaging

Background

Cardiac involvement is a major contributor of morbidity and mortality in Fabry disease (FD). Early detection and accurate evaluation of the disease progression is important in management. Cardiovascular magnetic resonance (CMR) derived feature fracking (FT) is a validated quantitative method of assessing myocardial deformation which may reflect early changes of myocardial function and track disease severity. We sought to evaluate the utility of CMR-FT as a measure of myocardial dysfunction in FD.

Methods

Twenty FD patients (12 males, 40.8±14.9 years) and 20 age and sex matched healthy controls (10 males, 40.5±7.2 years) were prospectively enrolled. Subjects underwent CMR including cine, pre-/post-contrast T1 mapping and late gadolinium enhancement (LGE). FD patients were divided into three groups; group 1: patients without left ventricular hypertrophy (LVH) and LGE negative; group 2: patients with LVH positive, LGE either positive or negative; group 3: patients with LGE positive, LV wall thinning and heart failure. FT derived strain indices were measured and its associations with other processes were investigated.

Results

In FD patients, 14 (70%) had LVH and 4 (20%) had LGE. Compared with normal controls, LV global longitudinal strain (GLS) were reduced significantly in all three Fabry groups (all P<0.05), global circumferential strain (GCS) were reduced only in group 2 and group 3 (P<0.05). Among three FD groups, there were significant differences of LV GLS, GCS, native T1 value and extracellular volume fraction (ECV) (all P<0.01), group 1 had mild LV strain indices impairment, group 3 had the most severe LV strain indices. When compared between FD subgroups, GLS and GCS showed significant difference between each two groups (all P<0.05). There were weak correlations between the LV functional parameters (ejection fraction, LV mass index), maximal wall thickness, T1 mapping indices (native T1, ECV) and LV strain indices. The strongest relation was between global longitudinal early diastolic strain rate and native T1 value (r=0.783, P<0.01).

Conclusions

CMR strain imaging identifies myocardial deformation in FD in different stages. Strain imaging can track disease severity and may be an alternative method for follow-up of FD patients.

Clinical Significance of Papillary Muscles on Left Ventricular Mass Quantification Using Cardiac Magnetic Resonance Imaging: Reproducibility and Prognostic Value in Fabry Disease

PURPOSE

Accurate and reproducible assessment of left ventricular mass (LVM) is important in Fabry disease. However, it is unclear whether papillary muscles should be included in LVM assessed by cardiac magnetic resonance imaging (MRI). The purpose of this study was to evaluate the reproducibility and predictive value of LVM in patients with Fabry disease using different analysis approaches.

MATERIALS AND METHODS

A total of 92 patients (44±15 y, 61 women) with confirmed Fabry disease who had undergone cardiac MRI at a single tertiary referral hospital were included in this retrospective study. LVM was assessed at end-diastole using 2 analysis approaches, including and excluding papillary muscles. Adverse cardiac events were assessed as a composite end point, defined as ventricular tachycardia, bradycardia requiring device implantation, severe heart failure, and cardiac death. Statistical analysis included Cox proportional hazard models, Akaike information criterion, intraclass correlation coefficients, and Bland-Altman analysis.

RESULTS

Left ventricular end-diastolic volume, end-systolic volume, ejection fraction, and LVM all differed significantly between analysis approaches. LVM was significantly higher when papillary muscles were included versus excluded (157±71 vs. 141±62 g, P<0.001). Mean papillary mass was 16±11 g, accounting for 10%±3% of total LVM. LVM with pap illary muscles excluded had slightly better predictive value for the composite end point compared with LVM with papillary muscles included based on the model goodness-of-fit (Akaike information criterion 140 vs. 142). Interobserver agreement was slightly better for LVM with papillary muscles excluded compared with included (intraclass correlation coefficient 0.993 [95% confidence interval: 0.985, 0.996] vs. 0.989 [95% confidence interval: 0.975, 0.995]) with less bias and narrower limits of agreement.

CONCLUSIONS

Inclusion or exclusion of papillary muscles has a significant effect on LVM quantified by cardiac MRI, and therefore, a standardized analysis approach should be used for follow-up. Exclusion of papillary muscles from LVM is a reasonable approach in patients with Fabry disease given slightly better predictive value and reproducibility.

Increased Spread of Native T1 Values Assessed With MRI as a Marker of Cardiac Involvement in Fabry Disease

OBJECTIVE. Cardiac involvement is the leading cause of mortality in Fabry disease. Noninvasive markers of cardiac involvement are needed to identify patients at high risk. The purpose of this study was to evaluate the diagnostic potential of segmental native T1 spread as an imaging biomarker in Fabry disease. SUBJECTS AND METHODS. In this prospective study, 43 patients with confirmed Fabry disease (mean ± SD age, 46±14 years; 70% women) and 17 healthy control subjects (mean ± SD age, 44 ±13 years; 53% women) underwent 3-T cardiac MRI including modified Look-Locker inversion recovery T1 mapping. Segmental native T1 spread was calculated as the difference between maximum and minimum segmental native T1 values, expressed as an absolute value and as a relative percentage of global native T1. RESULTS. Absolute and relative segmental native T1 spreads were significantly higher in patients with Fabry disease than in healthy control subjects (absolute median, 115 vs 98 ms [p = 0.004]; relative median, 9.9% vs 8.0% [p < 0.001]) and correlated positively with quantitative late gadolinium enhancement (absolute, r = 0.434, p < 0.001; relative, r = 0.436, p < 0.001), indexed left ventricular mass (absolute, r = 0.316, p = 0.01; relative, r = 0.347, p = 0.007), and global longitudinal strain (absolute, r = 0.289, p = 0.03; relative, r = 0.277, p = 0.03). Relative segmental native T1 spread differentiated patients with Fabry disease from healthy control subjects (odds ratio, 1.44 [95% CI, 1.10-1.89]; p = 0.009). Interob-server agreement was excellent for both absolute (intraclass correlation coefficient, 0.932) and relative (intraclass correlation coefficient, 0.926) segmental native T1 spread. CONCLUSION. Increased native T1 spread is a reproducible imaging biomarker of cardiac involvement in Fabry disease and may be particularly useful in the evaluation of patients who cannot undergo late gadolinium enhancement imaging.

Left Ventricular Mass and Wall Thickness Measurements Using Echocardiography and Cardiac MRI in Patients with Fabry Disease: Clinical Significance of Discrepant Findings

Purpose

To compare transthoracic echocardiography (TTE) and cardiac MRI measurements of left ventricular mass (LVM) and maximum wall thickness (MWT) in patients with Fabry disease and evaluate the clinical significance of discrepancies between modalities.

Materials and Methods

Seventy-eight patients with Fabry disease (mean age, 46 years ± 14 [standard deviation]; 63% female) who underwent TTE and cardiac MRI within a 6-month interval between 2008 and 2018 were included in this retrospective cohort study. The clinical significance of measurement discrepancies was evaluated with respect to diagnosis of left ventricular hypertrophy (LVH), eligibility for disease-specific therapy, and prognosis. Statistical analysis included paired-sample t test, Cox proportional hazard models, Akaike information criterion (AIC), and intraclass correlation coefficients.

Results

LVM indexed to body surface area (LVMI) and MWT were significantly higher at TTE compared with MRI (105 g/m² ± 48 vs 78 g/m² ± 36, P < .001 and 14 mm ± 4 vs 13 mm ± 5, P = .008, respectively). LVH classification was discordant between modalities in 23 patients (29%) (P < .001). Eligibility for disease-specific therapy based on MWT was discordant between modalities in 20 patients (26%) (P < .001). LVMI assessed with MRI was a better predictor of the combined endpoint compared with LVMI assessed with TTE (AIC, 127 vs 131). Interobserver agreement for LVMI and MWT was higher for MRI (intraclass correlation coefficient, 0.951 and 0.912, respectively) compared with TTE (intraclass correlation coefficient, 0.940 and 0.871; respectively).

Conclusion

TTE overestimates LVM and MWT and has lower reproducibility compared with cardiac MRI in Fabry disease. Measurement discrepancies between modalities are clinically significant with respect to diagnosis of LVH, prognosis, and treatment decisions.© RSNA, 2020.

Current and Investigational Therapeutics for Fabry Disease

Fabry disease (FD) is an X-linked lysosomal storage disease caused by a deficiency in the lysosomal enzyme α-galactosidase (α-GAL). This in turn leads to the buildup of globotriaosylceramide, resulting classically in progressive kidney disease, peripheral neuropathy, early-onset cerebrovascular disease, gastrointestinal symptoms, hypertrophic cardiomyopathy, arrhythmias, corneal whorls, and angiokeratomas. The diagnosis of FD relies on identification of a low α-GAL enzyme activity, identification of a genetic mutation, or histologic evidence of disease. With more than 900 mutations identified, there is phenotypic variability deriving from both mutational effects as well as the effect of skewed X-inactivation in females. Treatment of this disease has relied on intravenous replacement of the deficient enzyme with agalsidase α or agalsidase β. However, treatment options for some patients with FD have recently expanded, with the approval of migalastat, an oral molecular chaperone. In addition to chaperone-based therapies, there are several additional therapies under development that could substantially reshape treatment options for patients with FD. Four approaches to gene therapy, through both ex vivo and in vivo methods, are under development. Another approach is through the administration of α-GAL mRNA to help stimulate production of α-GAL, which is another unique form of therapy. Finally, substrate reduction therapies act as inhibitors of glucosylceramide synthase, thus inhibiting the production of GB-3, promise another oral option to treat FD. This article will review the literature around current therapies as well as these newer therapeutics agents in the pipeline for FD.

Advances in MRI Applications to Diagnose and Manage Cardiomyopathies

PURPOSE OF REVIEW

The prevalence of heart failure continues to rise, and imaging characterization of the cardiomyopathic process is important for identifying myocardial disease, initiating appropriate treatment, and improving outcomes. We aimed to summarize recent advances in cardiac magnetic resonance imaging (CMR) applications for the diagnosis, characterization, and implications on management of various cardiomyopathies.

RECENT FINDINGS

Parametric mapping by CMR has emerged as an important advancement in quantification of myocardial fibrosis, increased extracellular space, and myocardial edema. In addition, improved assessment of myocardial function with myocardial strain assessment may provide early identification of patients at risk and determining responsiveness to therapeutic interventions. Novel MRI techniques and the advent of artificial intelligence may help to uncover important mechanistic insights into the cardiomyopathic process. Innovative CMR techniques continue to evolve, and it will be of interest to determine how these advances can be incorporated into clinical practice to improve diagnosis, treatment, and management of patients with cardiomyopathies.

Multimodality Imaging Assessment of Fabry Disease

Fabry disease is a lysosomal storage disease with a variety of cardiac manifestations. Although not specific for a diagnosis of Fabry disease, certain cardiac imaging findings may be highly suggestive of the diagnosis of Fabry disease in previously undiagnosed patients or cardiac involvement for patients with a known diagnosis of Fabry disease. In this review, we explore the current applications of multimodality cardiac imaging in the diagnosis and monitoring of patients with Fabry disease. Additionally, data regarding tissue characterization by cardiac magnetic resonance imaging and novel nuclear imaging techniques and their role in evaluating phenotype development is discussed.

Left Ventricular Hypertrophy and Late Gadolinium Enhancement at Cardiac MRI Are Associated with Adverse Cardiac Events in Fabry Disease

Background Cardiac involvement is the leading cause of mortality in patients with Fabry disease. Identification of imaging findings that predict adverse cardiac events is needed to enable identification of high-risk patients. Purpose To establish the prognostic value of cardiac MRI findings in men and women with Fabry disease. Materials and Methods Consecutive women and men with gene-positive Fabry disease who had undergone cardiac MRI at a single large tertiary referral hospital between March 2008 and January 2019 were included in this retrospective cohort study. Evaluators of cardiac MRI studies were blinded to all clinical information. Adverse cardiac events were assessed as a composite end point, defined as ventricular tachycardia, bradycardia requiring device implantation, severe heart failure, and cardiac death. Statistical analysis included Cox proportional hazard models adjusted for age and Mainz Severity Score Index (a measure of the severity of Fabry disease). Results Ninety patients (mean age, 44 years ± 15 [standard deviation]; 59 women) were evaluated. After a median follow-up period of 3.6 years, the composite end point was reached in 21 patients (incidence rate, 7.6% per year). Left ventricular hypertrophy (LVH) and late gadolinium enhancement (LGE) were independent predictors of the composite end point in adjusted analysis (LVH hazard ratio [HR], 3.0; 95% confidence interval [CI]: 1.1, 8.1; P = .03; and LGE HR, 7.2; 95% CI: 1.5, 34; P = .01). Patients with extensive LGE (≥15% of left ventricular mass) were at highest risk (HR, 12; 95% CI: 2.0, 67; P = .006). Sex did not modify the relationship between the composite end point and any of the cardiac MRI parameters, including LVH (P = .15 for interaction term) and LGE (P = .38 for interaction term). Conclusion Cardiac MRI findings of left ventricular hypertrophy and late gadolinium enhancement can be used to identify patients with Fabry disease who are at high risk of adverse cardiac events. © RSNA, 2019 See also the editorial by Zimmerman in this issue.

Loss of base-to-apex circumferential strain gradient assessed by cardiovascular magnetic resonance in Fabry disease: relationship to T1 mapping, late gadolinium enhancement and hypertrophy

BACKGROUND

Cardiac involvement is common and is the leading cause of mortality in Fabry disease (FD). We explored the association between cardiovascular magnetic resonance (CMR) myocardial strain, T1 mapping, late gadolinium enhancement (LGE) and left ventricular hypertrophy (LVH) in patients with FD.

METHODS

In this prospective study, 38 FD patients (45.0 ± 14.5 years, 37% male) and 8 healthy controls (40.1 ± 13.7 years, 63% male) underwent 3 T CMR including cine balanced steady-state free precession (bSSFP), LGE and modified Look-Locker Inversion recovery (MOLLI) T1 mapping. Global longitudinal (GLS) and circumferential (GCS) strain and base-to-apex longitudinal strain (LS) and circumferential strain (CS) gradients were derived from cine bSSFP images using feature tracking analysis.

RESULTS

Among FD patients, 8 had LVH (FD LVH+, 21%) and 17 had LGE (FD LGE+, 45%). Nineteen FD patients (50%) had neither LVH nor LGE (FD LVH- LGE-). None of the healthy controls had LVH or LGE. FD patients and healthy controls did not differ significantly with respect to GLS (- 15.3 ± 3.5% vs. - 16.3 ± 1.5%, p = 0.45), GCS (- 19.4 ± 3.0% vs. -19.5 ± 2.9%, p = 0.84) or base-to-apex LS gradient (7.5 ± 3.8% vs. 9.3 ± 3.5%, p = 0.24). FD patients had significantly lower base-to-apex CS gradient (2.1 ± 3.7% vs. 6.5 ± 2.2%, p = 0.002) and native T1 (1170.2 ± 37.5 ms vs. 1239.0 ± 18.0 ms, p < 0.001). Base-to-apex CS gradient differentiated FD LVH- LGE- patients from healthy controls (OR 0.42, 95% CI: 0.20 to 0.86, p = 0.019), even after controlling for native T1 (OR 0.24, 95% CI: 0.06 to 0.99, p = 0.049). In a nested logistic regression model with native T1, model fit was significantly improved by the addition of base-to-apex CS gradient (χ2(df = 1) = 11.04, p < 0.001). Intra- and inter-observer agreement were moderate to good for myocardial strain parameters: GLS (ICC 0.849 and 0.774, respectively), GCS (ICC 0.831 and 0.833, respectively), and base-to-apex CS gradient (ICC 0.737 and 0.613, respectively).

CONCLUSIONS

CMR reproducibly identifies myocardial strain abnormalities in FD. Loss of base-to-apex CS gradient may be an early marker of cardiac involvement in FD, with independent and incremental value beyond native T1.