Functional and Morphological Parameters with Tissue Characterization of Cardiovascular Magnetic Imaging in Clinically Verified "Infarct-like Myocarditis"

Identifying myocardial injuries in "normal-appearing" myocardium in pediatric patients with clinically suspected myocarditis using mapping techniques

Background

Mapping techniques using cardiac magnetic resonance imaging have significantly improved the diagnostic accuracy for myocarditis with focal myocardial injuries. The aim of our study was to determine whether T1 and T2 mapping techniques could identify diffuse myocardial injuries in "normal-appearing" myocardium in pediatric patients with clinically suspected myocarditis and to evaluate the associations between diffuse myocardial injuries and cardiac function parameters.

Methods

Forty-six subjects were included in this study: 20 acute myocarditis patients, 11 subacute/chronic myocarditis patients and 15 control children. T2 values, native T1 values and the extracellular volume (ECV) of "normal-appearing" myocardium were compared among the three groups of patients. Associations between diffuse myocardial injuries and cardiac function parameters were also evaluated.

Results

The ECV of "normal-appearing" myocardium was significantly higher in the subacute/chronic myocarditis group than in the control group (30.1 ± 0.9 vs 27.0 ± 0.6, P =0.004). No significant differences in T1 and T2 values between the acute myocarditis and control groups were found. In the subacute/chronic myocarditis group, a significant association between ECV and left ventricle ejection fraction was found (P=0.03).

Conclusions

Diffuse myocardial injuries are likely to occur in subacute/chronic myocarditis patients with prolonged inflammatory responses. Mapping techniques have great value for the diagnosis and monitoring of myocarditis.

The role of Cardiac Magnetic Resonance (CMR) in the diagnosis of cardiomyopathy: A systematic review

Background

Myocardial pathologies are significant causes of morbidity and mortality in patients worldwide. Ischemic and non-ischemic cardiomyopathies have become a worldwide epidemic of the 21st century with an increasing impact on health care systems. The 2012 European Society of Cardiology and 2013 American College of Cardiology Foundation/American Heart Association guidelines provide current therapy guidance to reduce mortality and morbidity.

Methods

This was a systematic review involving cardiac magnetic resonance (CMR) studies for the diagnosis of cardiomyopathy from January 2013 to April 2017. Out of 62 reviewed studies, only 12 were included in our study.

Results

The average sensitivity and specificity of CMR in the diagnosis of cardiomyopathy was 86.75% (95% confidence interval [CI], 70.30% to 92.58%) and 81.75% (95% CI, 73.0% to 87.6%), respectively, and the positive predictive and negative predictive values were 80.17% and 86.75%, respectively.

Conclusion

Despite some limitations, our study shows that CMR has high sensitivity, specificity, and positive predictive value in diagnosing different types of cardiomyopathy. CMR may be used to differentiate types of cardiomyopathy, accurately quantify the chamber dimensions, volumes, and cardiac function, which make it useful for prognosis as well.

The role of cardiac magnetic resonance (CMR) in the diagnosis of cardiomyopathy: A systematic review

Background

Myocardial pathologies are significant causes of morbidity and mortality in patients worldwide. Ischemic and non-ischemic cardiomyopathies have become a worldwide epidemic of the 21st century with an increasing impact on health care systems. The 2012 European Society of Cardiology and 2013 American College of Cardiology Foundation/American Heart Association guidelines provide current therapy guidance to reduce mortality and morbidity.

Methods

This was a systematic review involving cardiac magnetic resonance (CMR) studies for the diagnosis of cardiomyopathy from January 2013 to April 2017. Out of 62 reviewed studies, only 12 were included in our study.

Results

The average sensitivity and specificity of CMR in the diagnosis of cardiomyopathy was 86.75% (95% confidence interval [CI], 70.30% to 92.58%) and 81.75% (95% CI, 73.0% to 87.6%), respectively, and the positive predictive and negative predictive values were 80.17% and 86.75%, respectively.

Conclusion

Despite some limitations, our study shows that CMR has high sensitivity, specificity, and positive predictive value in diagnosing different types of cardiomyopathy. CMR may be used to differentiate types of cardiomyopathy, accurately quantify the chamber dimensions, volumes, and cardiac function, which make it useful for prognosis as well.

Diagnostic Performance of Extracellular Volume, Native T1, and T2 Mapping Versus Lake Louise Criteria by Cardiac Magnetic Resonance for Detection of Acute Myocarditis: A Meta-Analysis

BACKGROUND

The Lake Louise Criteria (LLC) were established in 2009 and are the recommended cardiac magnetic resonance imaging criterion for diagnosing patients with suspected myocarditis. Subsequently, newer parametric imaging techniques which can quantify T1, T2, and the extracellular volume (ECV) have been developed and may provide additional utility in the diagnosis of myocarditis. However, whether their diagnostic accuracy is superior to LLC remains unclear. In this meta-analysis, we compared the diagnostic performance of native T1, T2, ECV to LLC in diagnosing acute myocarditis.

METHODS AND RESULTS

We searched PubMed for published studies of LLC, native T1, ECV, and T2 diagnostic criteria used to diagnose acute myocarditis. Seventeen studies were included, with a total of 867 myocarditis patients and 441 control subjects. Pooled sensitivity, specificity, and diagnostic odds ratio of all diagnostic tests were assessed by bivariate analysis. LLC had a pooled sensitivity of 74%, specificity of 86%, and diagnostic odds ratio of 17.7. Native T1 had a significantly higher sensitivity than LLC (85% versus 74%, P=0.025). Otherwise, there was no significant difference in sensitivity, specificity, and diagnostic odds ratio when comparing LLC to native T1, T2, or ECV.

CONCLUSIONS

Native T1, T2, and ECV mapping provide comparable diagnostic performance to LLC. Although only native T1 had significantly better sensitivity than LLC, each technique offers distinct advantages for evaluating and characterizing myocarditis when compared with the LLC.

Diagnostic and prognostic value of cardiac magnetic resonance in acute myocarditis: a systematic review and meta-analysis

While diagnostic criteria were elaborated for acute myocarditis using cardiac magnetic resonance (CMR) in 2009, studies have since examined the yield of traditional and novel CMR parameters to achieve greater accuracy and to predict clinical outcomes. The purpose of this systematic review and meta-analysis was to determine the diagnostic and prognostic value of CMR parameters for acute myocarditis. MEDLINE and EMBASE were systematically searched for original studies that reported CMR parameters in adult patients suspected of acute myocarditis. Each CMR parameter's binary prevalence, mean value and standard deviation were extracted. Parameters were meta-analyzed using a random-effects model to generate standardized mean differences. After screening 1492 abstracts, 53 studies were included encompassing 2823 myocarditis patients and 803 controls. Pooled standardized mean differences between myocarditis patients and controls were: T2 mapping time 2.26 (95% CI 1.50-3.02), extracellular volume 1.64 (95% CI 0.87-2.42), LGE percentage 1.30 (95% CI 0.95-1.64), T1 mapping time 1.18 (95% CI 0.35-2.01), T2 ratio 1.17 (95% CI 0.80-1.54), and EGE ratio 0.93 (95% CI 0.66-1.19). Prolonged T1 mapping time had the highest sensitivity (82%), pericardial effusion had the highest specificity (99%). Baseline LV dysfunction and the presence of LGE were predictive of major adverse cardiac events. The results support integration of parametric mapping criteria in the diagnostic criteria for myocarditis. The presence of baseline LV dysfunction and LGE predict patients at higher risk of adverse events.

Clinical use of cardiac PET/MRI: current state-of-the-art and potential future applications

Combined PET/MRI is a novel imaging method integrating the advances of functional and morphological MR imaging with PET applications that include assessment of myocardial viability, perfusion, metabolism of inflammatory tissue and tumors, as well as amyloid deposition imaging. As such, PET/MRI is a promising tool to detect and characterize ischemic and non-ischemic cardiomyopathies. To date, the greatest benefit may be expected for diagnostic evaluation of systemic diseases and cardiac masses that remain unclear in cardiac MRI, as well as for clinical and scientific studies in the setting of ischemic cardiomyopathies. Diagnosis and therapeutic monitoring of cardiac sarcoidosis has the potential of a possible 'killer-application' for combined cardiac PET/MRI. In this article, we review the current evidence and discuss current and potential future applications of cardiac PET/MRI.

Clinical applications of multi-parametric CMR in myocarditis and systemic inflammatory diseases

Cardiac magnetic resonance (CMR) has changed the management of suspected viral myocarditis by providing a ‘positive’ diagnostic test and has lead to new insights into myocardial involvement in systemic inflammatory conditions. In this review we analyse the use of CMR tissue characterisation techniques across the available studies including T2 weighted imaging, early gadolinium enhancement, late gadolinium enhancement, Lake Louise Criteria, T2 mapping, T1 mapping and extracellular volume assessment. We also discuss the use of multiparametric CMR in acute cardiac transplant rejection and a variety of inflammatory conditions such as sarcoidosis, systemic lupus erythrematous, rheumatoid arthritis and systemic sclerosis.

Clinical and magnetic resonance evolution of "infarct-like" myocarditis

AIMS

To analyse the clinical and magnetic resonance evolution of myocarditis in patients with an "infarct-like" presentation pattern.

METHODS

The study is a retrospective analysis of 52 patients with clinical diagnosis of "infarct-like" myocarditis confirmed by CMR as acute myocarditis according to Lake Louise criteria and 6 months follow-up. The CMR protocol included T2-weighted (oedema), early (hyperaemia) and late (fibrosis/necrosis) gadolinium enhancement sequences, according to Lake Louise criteria. Clinical and radiological follow-up by CMR was performed after a median time interval of 6 months (interquartile range 5-8). Quantitative outcomes were checked for normality and compared with the non-parametric Wilcoxon's test for matched data.

RESULTS

At the clinical follow-up all patients were free of symptoms and reported no cardiac complications. The CMR follow-up evidenced a significant increase of the ejection fraction (from 53 ± 6 to 55 ± 4%, p = 0.03), a decrease of the ventricular mass [from 67.0 (58.8-79.0) to 61.0 (54.0-67.0), p < 0.0001] without significant modification of the cardiac volume index (p = 0.26). No patient had residual oedema or capillary leakage: the T2 ratio decreased from 3.94 (3.00-4.86) to 0.98 (0.75-1.17) with p < 0.0001 and the Early gadolinium enhancement (EGE) ratio from 5.7 (4.8-6.5) to 2.9 (2.4-3.2) with p < 0.0001. Late gadolinium enhancement (LGE) persisted over the course of the follow-up in 48/52 patients, but with a significant reduction in every patient (LGE % from 34.3 ± 9.1 to 19.4 ± 6.6%; p < 0.0001).

CONCLUSION

Patients diagnosed with "infarct-like" myocarditis, according to both clinical and CMR examinations may look forward to a positive evolution with a good prognosis.