Myocardial involvement in systemic lupus erythematosus detected by magnetic resonance imaging

The Significance of Parametric Mapping in Advanced Cardiac Imaging

Cardiac magnetic resonance imaging has witnessed a transformative shift with the integration of parametric mapping techniques, such as T1 and T2 mapping and extracellular volume fraction. These techniques play a crucial role in advancing our understanding of cardiac function and structure, providing unique insights into myocardial tissue properties. Native T1 mapping is particularly valuable, correlating with histopathological fibrosis and serving as a marker for various cardiac pathologies. Extracellular volume fraction, an early indicator of myocardial remodeling, predicts adverse outcomes in heart failure. Elevated T2 relaxation time in cardiac MRI indicates myocardial edema, enabling noninvasive and early detection in conditions like myocarditis. These techniques offer precise insights into myocardial properties, enhancing the accuracy of diagnosis and prognosis across a spectrum of cardiac conditions, including myocardial infarction, autoimmune diseases, myocarditis, and sarcoidosis. Emphasizing the significance of these techniques in myocardial tissue analysis, the review provides a comprehensive overview of their applications and contributions to our understanding of cardiac diseases.

The value of cardiac magnetic resonance post-contrast T1 mapping in improving the evaluation of myocardial infarction

Objective

To explore the additional value of cardiac magnetic resonance (CMR) post-contrast T1 mapping in the detection of myocardial infarction, compared with late gadolinium enhancement (LGE).

Materials and methods

A CMR database of consecutive patients with myocardial infarction was retrospectively analyzed. All patients were scanned at 3 T magnetic resonance; they underwent conventional CMR (including LGE) and post-contrast T1 mapping imaging. Two radiologists interpreted the CMR images using a 16-segment model. The first interpretation included only LGE images. After 30 days, the same radiologists performed a second analysis of random LGE images, with the addition of post-contrast T1 mapping images. Images were analyzed to diagnose myocardial scars, and the transmural extent of each scar was visually evaluated. Diagnoses retained after LGE were compared with diagnoses retained after the addition of post-contrast T1 mapping.

Results

In total, 80 patients (1,280 myocardial segments) were included in the final analysis. After the addition of post-contrast T1 mapping, eight previously unidentified subendocardial scars were detected. Compared with LGE images, the percentage of infarcted segments was higher after the addition of post-contrast T1 mapping images (21.7% vs. 22.3%, P = 0.008), the percentage of uncertain segments was lower after the addition of post-contrast T1 mapping (0.8% vs. 0.1%, P = 0.004), and the percentage of uncertain transmural extent of scarring was lower after the addition of post-contrast T1 mapping (0.9% vs. 0.1%, P = 0.001).

Conclusion

The addition of post-contrast T1 mapping after LGE helps to improve the detection of myocardial infarction, as well as the assessment of the transmural extent of scarring.

Myocardial Involvement in Rheumatic Disorders

PURPOSE OF REVIEW

Autoimmune rheumatic diseases (ARDs) affect 8% of the population and approximately 78% of patients are women. Myocardial disease in ARDs is the endpoint of various pathophysiologic mechanisms including atherosclerosis, valvular disease, systemic, myocardial, and/or vascular inflammation, as well as myocardial ischemia and replacement/diffuse fibrosis.

RECENT FINDINGS

The increased risk of CVD in ARDs leads to excess comorbidity not fully explained by traditional cardiovascular risk factors. It seems that the chronic inflammatory status typically seen in ARDs, promotes both the development of myocardial inflammation/fibrosis and the acceleration of atherosclerosis. CMR (cardio-vascular magnetic resonance) is the ideal imaging modality for the evaluation of cardiac involvement in patients with ARDs, as it can simultaneously assess cardiac function and characterize myocardial tissues with regard to oedema and fibrosis. Due to its high spatial resolution, CMR is capable of identifying various disease entities such as myocardial oedema /inflammation, subendocardial vasculitis and myocardial fibrosis, that are often missed by other imaging modalities, notably at an early stage of development. Although generally accepted guidelines about the application of CMR in ARDs have not yet been formulated, according to our experience and the available published literature, we recommend CMR in ARD patientS with new-onset heart failure (HF), arrhythmia, for treatment evaluation/change or if there is any mismatch between patient symptoms and routine non-invasive evaluation.

The heart in systemic lupus erythematosus - A comprehensive approach by cardiovascular magnetic resonance tomography

Background

In systemic lupus erythematosus (SLE), cardiac manifestations, e.g. coronary artery disease (CAD) and myocarditis are leading causes of morbidity and mortality. The prevalence of subclinical heart disease in SLE is unknown. We studied whether a comprehensive cardiovascular magnetic resonance (CMR) protocol may be useful for early diagnosis of heart disease in SLE patients without known CAD.

Methods

In this prospective, observational, cross-sectional study CMR including cine, late gadolinium enhancement (LGE) and stress perfusion sequences, ECG, and blood sampling were performed in 30 consecutive SLE patients without known CAD. All patients fulfilled at least 4/11 American College of Rheumatology (ACR) Criteria for the classification of SLE.

Results

30 patients (83% female) were enrolled, mean age was 45±14 years and mean SLE disease duration was 10±8 years. 80% had low to moderate disease activity. All had a low SLE damage index. CMR was abnormal in 13/30 (43%), showing LGE in 9/13, stress perfusion deficits in 5/13 and pericardial effusion (PE) in 7/13. Patients with non-ischemic LGE had more often microalbuminuria while patients with stress perfusion deficits a history of hypertension, renal disorder as ACR criterion, repolarisation abnormalities on ECG and larger LV enddiastolic volume index. There was no correlation between clinical symptoms and CMR results.

Conclusion

Our study shows that cardiac involvement as observed by CMR is frequent in SLE and not necessarily associated with typical symptoms. CMR may thus help to detect subclinical cardiac involvement, which could lead to earlier treatment. Additionally we identify possible risk factors associated with cardiac involvement.

Cardiac magnetic resonance imaging abnormalities in systemic lupus erythematosus: a preliminary report

The purpose of this prospective, pilot study was to determine whether differences in myocardial T2 relaxivity can be identified among active systemic lupus erythematosus (SLE) patients with clinically suspected SLE myocarditis, other active SLE patients, inactive SLE patients and age and gender matched controls. Eleven consecutive female patients (six with active SLE and five with inactive SLE), and five age, gender and race matched healthy controls underwent imaging with echocardiography and cardiac magnetic resonance imaging (MRI). Echocardiographic measurements included left ventricular end diastolic (LVEDV) and end systolic volumes (LVESV), and mass (LVM) (all indexed to body mass); ejection fraction and cardiac output. The cardiac MRI measurement was the T2 relaxation time (an index of soft tissue signal, with higher levels suggestive of increased tissue water content). Patients with active SLE had significantly higher LVEDVand LVM than inactive SLE patients and healthy controls, and significantly larger LVESV than healthy controls. Myocardial T2 relaxation times were significantly higher in patients with active SLE compared to those with inactive SLE and to healthy controls, and remained higher even after excluding the two active SLE patients who had clinical myocarditis. The four active SLE patients who underwent repeat cardiac imaging studies after clinical improvement showed normalization of these myocardial abnormalities. The conclusion was that active SLE patients demonstrate abnormalities in myocardial structure manifested by high myocardial T2 relaxation times that normalized after clinical improvement in disease activity. These findings suggest that T2 relaxation values are a sensitive indicator of myocardial disease in patients with SLE and that myocardial T2 relaxation abnormality frequently occur in patients with active SLE, even in the absence of myocardial involvement by clinical criteria.

Cardiovascular magnetic resonance in rheumatology: Current status and recommendations for use

Targeted therapies in connective tissue diseases (CTDs) have led to improvements of disease-associated outcomes, but life expectancy remains lower compared to general population due to emerging co-morbidities, particularly due to excess cardiovascular risk. Cardiovascular magnetic resonance (CMR) is a noninvasive imaging technique which can provide detailed information about multiple cardiovascular pathologies without using ionizing radiation. CMR is considered the reference standard for quantitative evaluation of left and right ventricular volumes, mass and function, cardiac tissue characterization and assessment of thoracic vessels; it may also be used for the quantitative assessment of myocardial blood flow with high spatial resolution and for the evaluation of the proximal coronary arteries. These applications are of particular interest in CTDs, because of the potential of serious and variable involvement of the cardiovascular system during their course. The International Consensus Group on CMR in Rheumatology was formed in January 2012 aiming to achieve consensus among CMR and rheumatology experts in developing initial recommendations on the current state-of-the-art use of CMR in CTDs. The present report outlines the recommendations of the participating CMR and rheumatology experts with regards to: (a) indications for use of CMR in rheumatoid arthritis, the spondyloarthropathies, systemic lupus erythematosus, vasculitis of small, medium and large vessels, myositis, sarcoidosis (SRC), and scleroderma (SSc); (b) CMR protocols, terminology for reporting CMR and diagnostic CMR criteria for assessment and quantification of cardiovascular involvement in CTDs; and (c) a research agenda for the further development of this evolving field.

Myocardial T1 mapping: techniques and potential applications

Myocardial fibrosis is a common endpoint in a variety of cardiac diseases and a major independent predictor of adverse cardiac outcomes. Short of histopathologic analysis, which is limited by sampling bias, most diagnostic modalities are limited in their depiction of myocardial fibrosis. Cardiac magnetic resonance (MR) imaging has the advantage of providing detailed soft-tissue characterization, and a variety of novel quantification methods have further improved its usefulness. Contrast material-enhanced cardiac MR imaging depends on differences in signal intensity between regions of scarring and adjacent normal myocardium. Diffuse myocardial fibrosis lacks these differences in signal intensity. Measurement of myocardial T1 times (T1 mapping) with gadolinium-enhanced inversion recovery-prepared sequences may depict diffuse myocardial fibrosis and has good correlation with ex vivo fibrosis content. T1 mapping calculates myocardial T1 relaxation times with image-based signal intensities and may be performed with standard cardiac MR imagers and radiologic workstations. Myocardium with diffuse fibrosis has greater retention of contrast material, resulting in T1 times that are shorter than those in normal myocardium. Early studies have suggested that diffuse myocardial fibrosis may be distinguished from normal myocardium with T1 mapping. Large multicenter studies are needed to define the role of T1 mapping in developing prognoses and therapeutic assessments. However, given its strengths as a noninvasive method for direct quantification of myocardial fibrosis, T1 mapping may eventually play an important role in the management of cardiac disease.

Myocardial tissue characterization by magnetic resonance imaging: novel applications of T1 and T2 mapping

Cardiac magnetic resonance (CMR) imaging is a well-established noninvasive imaging modality in clinical cardiology. Its unsurpassed accuracy in defining cardiac morphology and function and its ability to provide tissue characterization make it well suited for the study of patients with cardiac diseases. Late gadolinium enhancement was a major advancement in the development of tissue characterization techniques, allowing the unique ability of CMR to differentiate ischemic heart disease from nonischemic cardiomyopathies. Using T2-weighted techniques, areas of edema and inflammation can be identified in the myocardium. A new generation of myocardial mapping techniques are emerging, enabling direct quantitative assessment of myocardial tissue properties in absolute terms. This review will summarize recent developments involving T1-mapping and T2-mapping techniques and focus on the clinical applications and future potential of these evolving CMR methodologies.

Myocardial tissue characterization by magnetic resonance imaging: novel applications of T1 and T2 mapping

Cardiac magnetic resonance (CMR) imaging is a well-established noninvasive imaging modality in clinical cardiology. Its unsurpassed accuracy in defining cardiac morphology and function and its ability to provide tissue characterization make it well suited for the study of patients with cardiac diseases. Late gadolinium enhancement was a major advancement in the development of tissue characterization techniques, allowing the unique ability of CMR to differentiate ischemic heart disease from nonischemic cardiomyopathies. Using T2-weighted techniques, areas of edema and inflammation can be identified in the myocardium. A new generation of myocardial mapping techniques are emerging, enabling direct quantitative assessment of myocardial tissue properties in absolute terms. This review will summarize recent developments involving T1-mapping and T2-mapping techniques and focus on the clinical applications and future potential of these evolving CMR methodologies.

Native myocardial T1 mapping by cardiovascular magnetic resonance imaging in subclinical cardiomyopathy in patients with systemic lupus erythematosus

BACKGROUND

Increased systemic inflammation has been linked to myocardial dysfunction and heart failure in patients with systemic lupus erythematosus (SLE). Accurate detection of early myocardial changes may be able to guide preventive intervention. We investigated whether multiparametric imaging by cardiovascular magnetic resonance can detect differences between controls and asymptomatic SLE patients.

METHODS AND RESULTS

A total of 33 SLE predominantly female patients (mean age, 40±9 years) underwent cardiovascular magnetic resonance for routine assessment of myocardial perfusion, function, and late gadolinium enhancement. T1 mapping was performed in single short-axis slice before and after 15 minutes of gadolinium administration. Twenty-one subjects with a low pretest probability and normal cardiovascular magnetic resonance served as a control group. Both groups had similar left ventricular volumes and mass and normal global systolic function. SLE patients had significantly reduced longitudinal strain (controls versus SLE, -20±2% versus -17±3%; P<0.01) and showed intramyocardial and pericardial late gadolinium enhancement. SLE patients had significantly increased native myocardial T1 (1056±27 versus 1152±46 milliseconds; P<0.001) and extracellular volume fraction (26±5% versus 30±6%; P=0.007) and reduced postcontrast myocardial T1 (454±53 versus 411±62 milliseconds; P=0.01). T1-derived indices were associated with longitudinal strain (r=0.37-0.47) but not with the presence of late gadolinium enhancement. Native myocardial T1 values showed the greatest concordance with the presence of clinical diagnosis of SLE.

CONCLUSIONS

In patients with SLE and free of cardiac symptoms, there is evidence of subclinical perimyocardial impairment. We further demonstrate that T1 mapping may have potential to detect subclinical myocardial involvement in patients with SLE.

The diagnostic role of cardiac magnetic resonance imaging in detecting myocardial inflammation in systemic lupus erythematosus. Differentiation from viral myocarditis

Objective

The objective of this paper is to evaluate the diagnostic role of cardiac magnetic resonance imaging (CMR) in detecting myocardial inflammation in systemic lupus erythematosus (SLE) and its differentiation from viral myocarditis.

Patients and methods

Fifty patients with suspected infective myocarditis (IM), with chest pain, dyspnoea or altered ECG, increase in troponin I and/or NT-pro BNP, with or without a history of flu-like syndrome or gastroenteritis and elevated C-reactive protein (CRP) within three to five (median four) weeks before admission, 25 active SLE patients, aged 38 ± 3 years, and 20 age-matched controls were prospectively evaluated by clinical assessment, ECG, echocardiogram and CMR. All patients underwent coronary angiography, and those with significant coronary artery disease (CAD) were excluded. CMR was performed using STIR T2-W (T2W), early T1-W (EGE) and late T1-W (LGE). Endomyocardial biopsies were performed when clinically indicated by current guidelines. Specimens were examined by immunohistological and polymerase chain reaction (PCR) analysis.

Results

Positive coronary angiography for CAD excluded 10/50 suspected IM and 5/25 active SLE. Positive clinical criteria for acute myocarditis were fulfilled by 28/40 suspected IM and only 5/20 active SLE. CMR was positive for myocarditis in 35/40 suspected IM and in 16/20 active SLE. Endomyocardial biopsy (EMB), performed in 25/35 suspected IM and 7/16 active SLE with positive CMR, showed positive immunohistology in 18/25 suspected IM and 3/7 active SLE. Infectious genomes were identified in 24/25 suspected IM and 1/7 active SLE.

Conclusions

CMR-positive IM patients were more symptomatic than active SLE. More than half of CMR-positive patients also had positive EMB. PCR was positive in almost all IM, but unusual in SLE. Due to the subclinical presentation of SLE myocarditis and the limitations of EMB, CMR presents the best alternative for the diagnosis of SLE myocarditis.

The protein binding substance ibuprofen does not affect the T1 time or partition coefficient in contrast-enhanced cardiovascular magnetic resonance

BACKGROUND

Contrast enhanced cardiovascular magnetic resonance (CMR) with T1 mapping enables quantification of diffuse myocardial fibrosis. Various factors, however, can interfere with T1 measurements. The purpose of the current study was to assess the effect of co-medication with a typical protein binding drug (ibuprofen) on T1 values in vitro and in vivo.

METHODS

50 vials were prepared with different concentrations of gadobenate dimeglumine, ibuprofen and human serum albumin in physiologic NaCl solution and imaged at 1.5T with a spin echo sequence at multiple TRs to measure T1 values and calculate relaxivities. 10 volunteers (5 men; 31 ± 6.3 years) were imaged at 1.5T. T1 values for myocardium and blood pool were determined for various time points after administration of 0.15 mmol/kg gadobenate dimeglumine using a modified look-locker inversion-recovery sequence before and after administration of ibuprofen over 24 hours. The partition coefficient was calculated as ΔR1myocardium/ΔR1blood, where R1=1/T1.

RESULTS

In vitro no significant correlation was found between relaxivity and ibuprofen concentration, neither in absence (r=-0.15, p=0.40) nor in presence of albumin (r=-0.32, p=0.30). In vivo there was no significant difference in post contrast T1 times of myocardium and blood, respectively and also in the partition coefficient between exam 1 and 2 (p>0.05). There was good agreement of the T1 times of myocardium and blood and the partition coefficient, respectively between exam 1 and 2.

CONCLUSIONS

Contrast enhanced T1 mapping is unaffected by co-medication with the protein binding substance ibuprofen and has an excellent reproducibility.

T1 mapping of the myocardium: intra-individual assessment of post-contrast T1 time evolution and extracellular volume fraction at 3T for Gd-DTPA and Gd-BOPTA

PURPOSE

Myocardial T1 relaxation time (T1 time) and extracellular volume fraction (ECV) are altered in patients with diffuse myocardial fibrosis. The purpose of this study was to perform an intra-individual assessment of normal T1 time and ECV for two different contrast agents.

METHODS

A modified Look-Locker Inversion Recovery (MOLLI) sequence was acquired at 3 T in 24 healthy subjects (8 men; 28 ± 6 years) at mid-ventricular short axis pre-contrast and every 5 min between 5-45 min after injection of a bolus of 0.15 mmol/kg gadopentetate dimeglumine (Gd-DTPA; Magnevist®) (exam 1) and 0.1 mmol/kg gadobenate dimeglumine (Gd-BOPTA; Multihance®) (exam 2) during two separate scanning sessions. T1 times were measured in myocardium and blood on generated T1 maps. ECVs were calculated as ΔR1 myocardium/ΔR1 blood*1-hematocrit.

RESULTS

Mean pre-contrast T1 relaxation times for myocardium and blood were similar for both the first and second CMR exam (p > 0.5). Overall mean post-contrast myocardial T1 time was 15 ± 2 ms (2.5 ± 0.7%) shorter for Gd-DTPA at 0.15 mmol/kg compared to Gd-BOPTA at 0.1 mmol/kg (p < 0.01) while there was no significant difference for T1 time of blood pool (p > 0.05). Between 5 and 45 minutes after contrast injection, mean ECV values increased linearly with time for both contrast agents from 0.27 ± 0.03 to 0.30 ± 0.03 (p < 0.0001). Mean ECV values were slightly higher (by 0.01, p < 0.05) for Gd-DTPA compared to Gd-BOPTA. Inter-individual variation of ECV was higher (CV 8.7% [exam 1, Gd-DTPA] and 9.4% [exam 2, Gd-BOPTA], respectively) compared to variation of pre-contrast myocardial T1 relaxation time (CV 4.5% [exam 1] and 3.0% [exam 2], respectively). ECV with Gd-DTPA was highly correlated to ECV by Gd-BOPTA (r = 0.803; p < 0.0001).

CONCLUSION

In comparison to pre-contrast myocardial T1 relaxation time, variation in ECV values of normal subjects is larger. However, absolute differences in ECV between Gd-DTPA and Gd-BOPTA were small and rank correlation was high. There is a small and linear increase in ECV over time, therefore ideally images should be acquired at the same delay after contrast injection.

Imaging assessment of cardiovascular disease in systemic lupus erythematosus

Systemic lupus erythematosus is a multisystem, autoimmune disease known to be one of the strongest risk factors for atherosclerosis. Patients with SLE have an excess cardiovascular risk compared with the general population, leading to increased cardiovascular morbidity and mortality. Although the precise explanation for this is yet to be established, it seems to be associated with the presence of an accelerated atherosclerotic process, arising from the combination of traditional and lupus-specific risk factors. Moreover, cardiovascular-disease associated mortality in patients with SLE has not improved over time. One of the main reasons for this is the poor performance of standard risk stratification tools on assessing the cardiovascular risk of patients with SLE. Therefore, establishing alternative ways to identify patients at increased risk efficiently is essential. With recent developments in several imaging techniques, the ultimate goal of cardiovascular assessment will shift from assessing symptomatic patients to diagnosing early cardiovascular disease in asymptomatic patients which will hopefully help us to prevent its progression. This review will focus on the current status of the imaging tools available to assess cardiac and vascular function in patients with SLE.

Shortened Modified Look-Locker Inversion recovery (ShMOLLI) for clinical myocardial T1-mapping at 1.5 and 3 T within a 9 heartbeat breathhold

BACKGROUND

T1 mapping allows direct in-vivo quantitation of microscopic changes in the myocardium, providing new diagnostic insights into cardiac disease. Existing methods require long breath holds that are demanding for many cardiac patients. In this work we propose and validate a novel, clinically applicable, pulse sequence for myocardial T1-mapping that is compatible with typical limits for end-expiration breath-holding in patients.

MATERIALS AND METHODS

The Shortened MOdified Look-Locker Inversion recovery (ShMOLLI) method uses sequential inversion recovery measurements within a single short breath-hold. Full recovery of the longitudinal magnetisation between sequential inversion pulses is not achieved, but conditional interpretation of samples for reconstruction of T1-maps is used to yield accurate measurements, and this algorithm is implemented directly on the scanner. We performed computer simulations for 100 ms

RESULTS

We found good agreement between the average ShMOLLI and MOLLI estimates for T1 < 1200 ms. In contrast to the original method, ShMOLLI showed no dependence on heart rates for long T1 values, with estimates characterized by a constant 4% underestimation for T1 = 800-2700 ms. In-vivo, ShMOLLI measurements required 9.0 ± 1.1 s (MOLLI = 17.6 ± 2.9 s). Average healthy myocardial T1 s by ShMOLLI at 1.5T were 966 ± 48 ms (mean ± SD) and 1166 ± 60 ms at 3T. In MI patients, the T1 in unaffected myocardium (1216 ± 42 ms) was similar to controls at 3T. Ischemically injured myocardium showed increased T1 = 1432 ± 33 ms (p < 0.001). The difference between MI and remote myocardium was estimated 15% larger by ShMOLLI than MOLLI (p < 0.04) which suffers from heart rate dependencies for long T1. The in-vivo variability within ShMOLLI T1-maps was only 14% (1.5T) or 18% (3T) higher than the MOLLI maps, but the MOLLI acquisitions were twice longer than ShMOLLI acquisitions.

CONCLUSION

ShMOLLI is an efficient method that generates immediate, high-resolution myocardial T1-maps in a short breath-hold with high precision. This technique provides a valuable clinically applicable tool for myocardial tissue characterisation.

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Key Words Collapse

MESH Headings

• Adult
• Algorithms
• Cardiac-Gated Imaging Techniques/instrumentation
• Computer Simulation
• Contrast Media
• Electrocardiography
• England
• Female
• Gadolinium DTPA
• Heart Rate
• Humans
• Image Interpretation, Computer-Assisted
• Magnetic Resonance Imaging/instrumentation
• Male
• Middle Aged
• Myocardial Infarction/pathology
• Myocardial Infarction/physiopathology
• Phantoms, Imaging
• Predictive Value of Tests
• Reproducibility of Results
• Respiratory Mechanics
• Time Factors

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Grants

• G0701128 Medical Research Council

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Affiliation(s)

Stefan K Piechnik University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK
Vanessa M Ferreira University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK Stephenson CMR Centre, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Canada
Erica Dall'Armellina University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK
Lowri E Cochlin Dept. of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
Andreas Greiser Siemens AG Healthcare Sector, Erlangen, Germany
Stefan Neubauer University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK
Matthew D Robson University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK

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Myocardial tissue characterization in systemic lupus erythematosus: value of a comprehensive cardiovascular magnetic resonance approach

Systemic lupus erythematosus (SLE) is a multi-organ inflammatory disorder mainly affecting women and is associated with high cardiovascular morbidity and mortality. We tested the utility of a comprehensive cardiovascular magnetic resonance approach to assess myocardial involvement and to determine its relation to disease activity in SLE patients. We studied 20 SLE patients (19 females, 35 ± 10 years) and 13 healthy volunteers (nine females, 28 ± 11 years). Classification followed the criteria of the American College of Rheumatology and assessment of SLE activity was based on the European Consensus Lupus Activity Measurement index. Cardiovascular magnetic resonance (CMR) was performed on a 1.5T scanner and included the following sequences: steady-state free precession, T2-weighted, early and late T1-weighted after gadolinium-DTPA injection. Ejection fraction was not significantly different between groups (controls: 63 ± 6, inactive SLE: 67 ± 7, active SLE 64 ± 8; P = 0.003 for all groups). In contrast, relative T2 ratio (myocardium to skeletal muscle) was significantly higher in active SLE than in the other groups (controls: 1.7 ± 0.3, inactive: 1.8 ± 0.2, active: 2.1 ± 0.2; P = 0.003). Similarly, early enhancement ratio was significantly higher in active SLE (controls: 2.4 ± 1.4, inactive: 2.8 ± 1.1, active: 4.5 ± 2.0, P = 0.39). Both relative T2 and early enhancement ratios significantly correlated with disease activity. Intramural foci of late enhancement were observed in three of eight patients (all with active SLE). Of the five patients with no late enhancement, only one had active disease. An imaging approach combining T2-weighted, early and late enhancement imaging is a useful tool to assess possible myocardial involvement in SLE. CMR parameters of global myocardial involvement correlate well with disease activity, but not with usual clinical signs as summarized in a cardiac score.

Optimization and validation of a fully-integrated pulse sequence for modified look-locker inversion-recovery (MOLLI) T1 mapping of the heart

PURPOSE

To optimize and validate a fully-integrated version of modified Look-Locker inversion-recovery (MOLLI) for clinical single-breathhold cardiac T1 mapping.

MATERIALS AND METHODS

A MOLLI variant allowing direct access to all pulse sequence parameters was implemented on a 1.5T MR system. Varying four critical sequence parameters, MOLLI was performed in eight gadolinium-doped agarose gel phantoms at different simulated heart rates. T1 values were derived for each variant and compared to nominal T1 values. Based on the results, MOLLI was performed in midcavity short-axis views of 20 healthy volunteers pre- and post-Gd-DTPA.

RESULTS

In phantoms, a readout flip angle of 35 degrees , minimum TI of 100 msec, TI increment of 80 msec, and use of three pausing heart cycles allowed for most accurate and least heart rate-dependent T1 measurements. Using this pulse sequence scheme in humans, T1 relaxation times in normal myocardium were comparable to data from previous studies, and showed narrow ranges both pre- and postcontrast without heart rate dependency.

CONCLUSION

We present an optimized implementation of MOLLI for fast T1 mapping with high spatial resolution, which can be integrated into routine imaging protocols. T1 accuracy is superior to the original set of pulse sequence parameters and heart rate dependency is avoided.

A Long-Term Follow-up after Cardiac Transplantation in a Lupus Patient: Case Report and Review of the Literature

Heart or heart-lung transplantations have only rarely been performed in patients with systemic lupus erythematosus (SLE), who like other patients with multi-system autoimmune diseases are traditionally excluded from consideration for such transplantations. In view of the limited experience with heart transplantation in these patients, we report the successful transplantation outcome in a lupus patient and review the literature in relation to graft and recipient conditions.

Utility of cardiac MRI for diagnosis and post-treatment follow-up of lupus myocarditis

Clinical myocardial involvement in systemic lupus erythematosus is rare. Lupus myocarditis is usually not detected until significant decrease in myocardial function becomes clinically evident. This case report describes MR imaging of lupus myocarditis that was used for diagnosis and follow up in a patient who declined cardiac biopsy. We also review the literature related to myocardial imaging by MRI.

Hydroxychloroquine-induced cardiotoxicity in a 39-year-old woman with systemic lupus erythematosus and systolic dysfunction

A 39-year-old woman with a history of systemic lupus erythematosus developed chest pain and conduction abnormalities. An echocardiographic examination revealed systolic dysfunction and ventricular thickening. Because of the unclear nature of her cardiac disease, right ventricular endomyocardial biopsy was performed. Light microscopy showed diffuse myocyte vacuolization without myocarditis, and transmission electron microscopy demonstrated sarcoplasmic myelinoid and curvilinear bodies, diagnostic of hydroxychloroquine toxicity. Among patients with autoimmune connective disorders, cardiac dysfunction may be a result of the disease or occasionally of its treatment. Although the nature of the cardiac disease (myocardial, valvular, or pericardial) can generally be evaluated echocardiographically, endomyocardial biopsy may be indicated to rule out diseases with a specific microscopic appearance, such as myocarditis or hydroxychloroquine cardiotoxicity.

Human myocardium: single-breath-hold MR T1 mapping with high spatial resolution--reproducibility study

A prospective study approved by the local ethics committee was performed to establish the normal range and reproducibility of myocardial T1 values as assessed with single-breath-hold T1 mapping with high spatial resolution. With a 1.5-T magnetic resonance (MR) imaging system, baseline and contrast material-enhanced modified Look-Locker inversion recovery, or MOLLI, imaging was performed in 15 healthy volunteers who had given written informed consent. Image quality scores and myocardial T1 values were derived for standard short-axis segments and sections. Results were compared with those from a second MR imaging study performed on the same day (baseline only) and those from a third study performed on a different day (baseline and contrast enhanced; eight volunteers). Intra- and interobserver agreement were determined. Myocardial T1 maps were obtained rapidly in a reproducible fashion. A normal range for baseline and postcontrast myocardial T1 was established (baseline mean T1 in short-axis sections, 980 msec +/- 53 [standard deviation]; 95% confidence interval: 964, 997; number of sections, 43). This technique could enable direct quantification of changes in tissue characteristics in ischemic and inflammatory myocardial diseases.

[Cardiovascular monitoring of patients with systemic lupus erythematosus]

Accelerated atherosclerotic cardiovascular disease is increasingly recognized as a major cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Cardiac manifestations of SLE are frequent and can involve almost all components of the heart. Pulmonary hypertension often develops during the course of SLE. The high incidence of cardiovascular complications may justify a screening of SLE patients in order to ensure early diagnosis and therapy. Results of diagnostic procedures that detect coronary insufficiency, surrogates of atherosclerotic burden and echocardiographic findings are often abnormal in SLE. However, evidence to support a routine screening for cardiovascular disease is currently not available. Therefore, based on the recommendations that have been proposed for other conditions associated with cardiovascular disease, we suggest assessment of risk factors and the performance of echocardiography at least annually in asymptomatic SLE patients. If two or more risk factors are present, an exercise ECG is recommended. The benefit, however, of screening SLE patients for cardiovascular disease has to be confirmed in prospective studies.

Myocarditis in systemic lupus erythematosus

Although clinical manifestations of myocarditis in systemic lupus erythematosus are uncommon, noninvasive cardiac testing may detect subclinical cases. The pathogenesis of myocarditis in systemic lupus erythematosus has been ascribed to many factors, including autoimmunity, medications, and coexisting diseases. Lupus myocarditis merits urgent clinical attention because of the likely progression to arrhythmias, conduction disturbances and heart block, dilated cardiomyopathy, and heart failure. Endomyocardial biopsy can be used to identify the underlying inflammatory histopathology. Usual therapy includes high-dose corticosteroids, in addition to standard cardiac medications.

MRI changes in myocarditis--evaluation with spin echo, cine MR angiography and contrast enhanced spin echo imaging

AIM

Myocarditis is probably under-diagnosed with clinical criteria generally used for diagnosis. Magnetic resonance imaging (MRI) has shown promise in detecting heart muscle disorders and we set out to assess the role of cine magnetic resonance angiography (MRA) and contrast enhancement in myocarditis, as there is a need for a non-invasive tool that can aid prognosis and follow-up.

MATERIALS AND METHODS

Twenty patients were evaluated with T1 SE pre- and post-gadolinium enhancement and cine MRA. Four patients were histologically proven to have myocarditis, eight others were diagnosed as having myocarditis by clinical criteria and eight did not have myocarditis. Images were evaluated in a blinded fashion for regional wall motion abnormality and contrast enhancement pattern. Analysis of contrast enhancement by signal intensity measurement was also performed.

RESULTS

Focal myocardial enhancement with associated regional wall motion abnormality correlated with myocarditis in 10 out of 12 patients, two patients with abnormal focal enhancement alone also clinically had myocarditis. None of the non-myocarditis patients showed abnormal focal enhancement. Enhancement analysis suggests that focal corrected myocardial enhancement of > 40% is abnormal.

CONCLUSION

In the correct clinical context, focal myocardial enhancement on spin echo MRI strongly supports a diagnosis of myocarditis, especially when associated with regional wall motion abnormality.Roditi, G. H. (2000). Clinical Radiology55, 752-758.

Cardiovascular manifestations of systemic autoimmune diseases

The systemic autoimmune diseases are a protean group of illnesses that primarily affect the joints, muscles, and connective tissue. All aspects of the cardiovascular system can be involved with clinical consequences ranging from asymptomatic abnormalities to serious life-threatening conditions. This article discusses the cardiovascular manifestations of the systemic autoimmune diseases with particular focus on clinical pathophysiology and management.

Libman-Sacks Endocarditis with Unusual Features

Systemic lupus erythematosus is an autoimmune inflammatory disorder that affects many organs including the cardiovascular system. It involves pericardium, myocardium, endocardium, cardiac valves, and coronary vessels. Several autopsy series have shown an incidence of cardiac lesions of 48% to 74% but documentation of such lesions during life is rare. With increasing use of two-dimensional echocardiography and the Doppler technique, cardiac lesions are increasingly being detected in the living population with systemic lupus erythematosus. A higher association has been seen between antibodies against phospholipids and cardiac valvular abnormalities but there are few prospective data on their role in the development of cardiovascular abnormalities.

The left ventricle in systemic lupus erythematosus: initial observations and a five-year follow-up in a university medical center population

The objectives of this study were to determine the natural history of abnormalities in left ventricular size and function in patients with systemic lupus erythematosus and to determine whether changes in ventricular function can be attributed to a primary lupus cardiomyopathy. The design was a prospective 5-year follow-up study in a university hospital. There were 28 patients with systemic lupus erythematosis who were enrolled in an echocardiographic study from 1985 to 1986 and who were available for follow-up echocardiographic examinations. Patients were prospectively subgrouped according to the presence or absence of systemic hypertension. Twenty healthy volunteers participated as normal control subjects. Measurements of left ventricular mass index, mean wall thickness, volumes, and ejection fraction and Doppler indices of mitral inflow were performed on all patients and control subjects. Increases in left ventricular mass index, mean wall thickness, and end-systolic volume and decreases in ejection fraction were seen in the patients with lupus when compared with control subjects (p < or = 0.05) and were related to the presence of hypertension and coronary artery disease. In the group of patients without hypertension, no significant differences in left ventricular mass index, volumes, or ejection fraction were detected when compared with the control group. The normotensive patients did demonstrate mild abnormalities of mitral inflow that did not worsen during the follow-up period. It was concluded that abnormalities of systolic and diastolic left ventricular function are common in patients with lupus, are progressive over time, and are related to the coexistence of hypertension and coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial systolic function in systemic lupus erythematosus: a study based on radionuclide ventriculography

We assessed left ventricular systolic function by means of radionuclide ventriculography in 20 consecutive unselected patients with systemic lupus erythematosus. All patients had normal left ventricular systolic function (defined as ejection fraction greater than 45%) in a resting state. Regional wall motion abnormalities were, however, seen in 4 patients (20%). Of these 20 patients, 8 were able to exercise on a bicycle ergometer. These patients were subjected to exercise radionuclide ventriculography. Of these 8 patients, 3 (37.5%) had an abnormal ventriculographic response to exercise (as evidenced by a subnormal rise in ejection fraction or a fall, appearance of a new regional wall motion abnormality or worsening of a pre-existing one). This probably reflects subclinical left ventricular dysfunction unmasked by the stress of exercise. The clinical significance of these abnormalities on long-term myocardial function and their possible reversibility with remission of the disease needs to be assessed in future studies.

Sub-clinical systemic lupus erythematosus presenting with acute myocarditis

A 46 year old woman presented with fever and normochromic anaemia followed rapidly by severe myocardial failure, unresponsive to maximum inotropic support and broad spectrum antibiotics. There were no classical clinical stigmata of systemic lupus erythematosus (SLE) but a possible immunological cause was looked for, and on the basis of her immuno-serology a diagnosis of SLE-like disease was made. She responded rapidly to high dose steroids. The importance of considering the possibility of SLE or 'lupus overlap' in an acutely ill 'undiagnosed' patient is emphasized. The relevance of instigating appropriate immuno-serological tests in the course of such an illness is discussed.

Interventricular differences in myocardial T2 measurements: experimental and clinical studies

The goal of this study was to determine the accuracy, the reproducibility, and some of the tissue determinants of image-based myocardial T2 measurements. Image-based T2 calculations for the free walls of the right ventricle (RV) and left ventricle (LV), in vitro T2 determination (at 0.47 T), and water, fat, and collagen content analyses were performed in ex vivo hog hearts. T2 values of the RV and LV free walls were also determined from spin-echo images of 14 healthy human subjects. Preliminary reproducibility studies were performed with 10 sets of images acquired from a single subject. For both in vitro and image-based T2 values of hog hearts, RV T2 was significantly longer than LV T2. Water content was the only tissue factor to significantly correlate with in vitro and image-based T2 values. For the 14 human subjects studied, image-based T2 values calculated from the first- and third-echo images demonstrated a significant difference between LV and RV. The difference was not significant when the first- and second-echo images were used. Image-based T2 measurements of a single subject showed a coefficient of variation of 6.8% for the LV and 9.1% for the RV. The authors conclude that image-based T2 measurements of normal myocardium can be made with sufficient precision to identify differences of the magnitude of those found between RV and LV T2 values. Image-based T2 values of myocardium may provide useful data to aid in patient treatment.

Doppler echocardiographic evaluation of left ventricular diastolic function in patients with systemic lupus erythematosus

Subclinical myocardial involvement frequently occurs in patients with systemic lupus erythematosus (SLE). In this study, left ventricular diastolic function was assessed in 58 patients (54 female and 4 male; mean age 32 +/- 11 years) and in 40 sex-matched and age-matched healthy control subjects (37 female and 3 male; mean age 33 +/- 9 years) by means of pulsed Doppler echocardiography. All subjects had no clinical evidence of overt myocardial disease or abnormal left ventricular systolic function. Compared with the control group, patients with SLE had significantly prolonged isovolumic relaxation time (62 +/- 12 vs 80 +/- 14 msec; p less than 0.01), reduced peak early diastolic flow velocity (peak E) (82 +/- 18 vs 76 +/- 16 cm/sec; p less than 0.05), increased peak late diastolic flow velocity (peak A) (45 +/- 7 vs 53 +/- 8 cm/sec; p less than 0.01), reduced E/A ratio (1.81 +/- 0.32 vs 1.46 +/- 0.29; p less than 0.001), and lower deceleration rate of early diastolic flow velocity (EF slope) (489 +/- 151 vs 361 +/- 185 cm/sec2; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Imaging the pathology of myocardial infarction

In order to measure the effectiveness of new therapies a technique is needed which can measure quantitatively in vivo pathology. In cardiology, the introduction of thrombolytic agents, which lyse the initial thrombus, has given added stimulus to the search for techniques which would fill this role. In this paper the extent to which nuclear medicine and magnetic resonance imaging can meet the requirements is discussed.