Diagnostic role of strain imaging in atypical myocarditis by echocardiography and cardiac MRI

Improve myocardial strain estimation based on deformable groupwise registration with a locally low-rank dissimilarity metric

BACKGROUND

Current mainstream cardiovascular magnetic resonance-feature tracking (CMR-FT) methods, including optical flow and pairwise registration, often suffer from the drift effect caused by accumulative tracking errors. Here, we developed a CMR-FT method based on deformable groupwise registration with a locally low-rank (LLR) dissimilarity metric to improve myocardial tracking and strain estimation accuracy.

METHODS

The proposed method, Groupwise-LLR, performs feature tracking by iteratively updating the entire displacement field across all cardiac phases to minimize the sum of the patchwise signal ranks of the deformed movie. The method was compared with alternative CMR-FT methods including the Farneback optical flow, a sequentially pairwise registration method, and a global low rankness-based groupwise registration method via a simulated dataset (n = 20), a public cine data set (n = 100), and an in-house tagging-MRI patient dataset (n = 16). The proposed method was also compared with two general groupwise registration methods, nD + t B-Splines and pTVreg, in simulations and in vivo tracking.

RESULTS

On the simulated dataset, Groupwise-LLR achieved the lowest point tracking errors (p = 0.13 against pTVreg for the temporally averaged point tracking errors in the long-axis view, and p < 0.05 for all other cases), voxelwise strain errors (all p < 0.05), and global strain errors (p = 0.05 against pTVreg for the longitudinal global strain errors, and p < 0.05 for all other cases). On the public dataset, Groupwise-LLR achieved the lowest contour tracking errors (all p < 0.05), reduced the drift effect in late-diastole, and preserved similar inter-observer reproducibility as the alternative methods. On the patient dataset, Groupwise-LLR correlated better with tagging-MRI for radial strains than the other CMR-FT methods in multiple myocardial segments and levels.

CONCLUSIONS

The proposed Groupwise-LLR reduces the drift effect and provides more accurate myocardial tracking and strain estimation than the alternative methods. The method may thus facilitate a more accurate estimation of myocardial strains for clinical assessments of cardiac function.

Prognostic Value of Speckle Tracking Echocardiography-Derived Strain in Unmasking Risk for Arrhythmias in Children with Myocarditis

Background/Objectives: Risk assessment in pediatric myocarditis is challenging, particularly when left ventricular ejection fraction (LVEF) is preserved. This study aimed to evaluate LV myocardial deformation using speckle-tracking echocardiography (STE)-derived longitudinal +strain (LS) and assessed its diagnostic and prognostic value in children with myocarditis. Methods: Retrospective STE-derived layer-specific LV LS analysis was performed on echocardiograms from patients within the multicenter, prospective registry for pediatric myocarditis "MYKKE". Age- and sex-adjusted logistic regression and ROC analysis identified predictors of cardiac arrhythmias (ventricular tachycardia, ventricular fibrillation, atrioventricular blockage III°) and major adverse cardiac events (MACE: need for mechanical circulatory support (MCS), cardiac transplantation, and/or cardiac death). Results: Echocardiograms from 175 patients (median age 15 years, IQR 7.9-16.5 years; 70% male) across 13 centers were included. Cardiac arrhythmias occurred in 36 patients (21%), and MACE in 28 patients (16%). Impaired LV LS strongly correlated with reduced LVEF (r > 0.8). Impaired layer-specific LV LS, reduced LVEF, LV dilatation, and increased BSA-indexed LV mass, were associated with the occurrence of MACE and cardiac arrhythmias. In patients with preserved LVEF, LV LS alone predicted cardiac arrhythmias (p < 0.001), with optimal cutoff values of -18.0% for endocardial LV LS (sensitivity 0.69, specificity 0.94) and -17.0% for midmyocardial LV LS (sensitivity 0.81, specificity 0.75). Conclusions: In pediatric myocarditis, STE-derived LV LS is not only a valuable tool for assessing systolic myocardial dysfunction and predicting MACE but also identifies patients at risk for cardiac arrhythmias, even in the context of preserved LVEF.

The diagnosis and treatment of pediatric clinical myocarditis in China: a multicenter retrospective study

This study aims to examine the clinical characteristics and outcomes of clinical myocarditis in pediatric patients in China. This is a multicenter retrospective study. Children diagnosed with clinical myocarditis from 20 hospitals in China and admitted between January 1, 2015, and December 30, 2021, were enrolled. The clinical myocarditis was diagnosed based on the "Diagnostic Recommendation for Myocarditis in Children (Version 2018)". The clinical data were collected from their medical records. A total of 1210 patients were finally enrolled in this study. Among them, 45.6% had a history of respiratory tract infection. An abnormal electrocardiogram was observed in 74.2% of patients. Echocardiography revealed that 32.3% of patients had a left ventricular ejection fraction of less than 50%. Cardiac MRI was performed in 4.9% of children with clinical myocarditis, of which 61% showed localized or diffuse hypersignal on T2-weighted images. Serum levels of cardiac troponin I (cTnI), creatine kinase-MB (CK-MB), and N-terminal B-type natriuretic peptide (NT-proBNP) were higher in patients with fulminant myocarditis than in patients with myocarditis, making them potential risk factors for fulminant myocarditis. Following active treatment, 12.1% of patients were cured, and 79.1% were discharged with improvement.

CONCLUSION

Clinical myocarditis in children often presents with symptoms outside the cardiovascular system. CK-MB, cTnI, and NT-proBNP are important indicators for assessing clinical myocarditis. The electrocardiogram and echocardiogram findings in children with clinical myocarditis exhibit significant variability but lack specificity. Cardiac MRI can be a useful tool for screening clinical myocarditis. Most children with clinical myocarditis have a favorable prognosis.

WHAT IS KNOWN

• Pediatric myocarditis presents complex clinical manifestations and exhibits varying degrees of severity. Children with mild myocarditis generally have a favorable prognosis, while a small number of children with critically ill myocarditis experience sudden onset, hemodynamic disorders, and fatal arrhythmias. Therefore, early diagnosis and timely treatment of myocarditis are imperative.

WHAT IS NEW

• To the best of our knowledge, this multicenter retrospective study is the largest ever reported in China, aiming to reveal the clinical characteristics and outcomes of pediatric clinical myocarditis in China. We provided an extensive analysis of the clinical characteristics, diagnosis, treatment, prognosis, and factors impacting disease severity in pediatric clinical myocarditis in China, which provides insights into the epidemiological characteristics of pediatric clinical myocarditis.

Quantitative cardiac MRI parameters for assessment of myocarditis in children and adolescents: a systematic review and meta-analysis

AIM

To evaluate the role of quantitative cardiac magnetic resonance imaging (CMRI) parameters in myocarditis, including acute and chronic myocarditis (AM and CM), for children and adolescents.

MATERIALS AND METHODS

PRISMA principles were followed. PubMed, EMBASE, Web of Science, Cochrane Library, and grey literature were searched. The Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ) checklist were utilised for quality assessment. Quantitative CMRI parameters were extracted and a meta-analysis was performed in comparison with healthy controls. The overall effect size was measured as the weighted mean difference (WMD).

RESULTS

Ten quantitative CMRI parameters of seven studies were analysed. Compared with the control group, the myocarditis group reported longer native T1 relaxation time (WMD=54.00, 95% confidence interval [CI]: 33.21,74.79, p<0.001), longer T2 relaxation time (WMD=2.13, 95% CI: 0.98, 3.28, p<0.001), increased extracellular volume (ECV; WMD=3.13, 95% CI: 1.34,4.91, p=0.001), elevated early gadolinium enhancement (EGE) ratio (WMD=1.47, 95% CI: 0.65,2.28, p<0.001), and increased T2-weighted ratio (WMD=0.43, 95% CI: 0.21,0.64, p<0.001). The AM group had longer native T1 relaxation times (WMD=72.02, 95% CI: 32.78,111.27, p<0.001), increased T2-weighted ratios (WMD=0.52, 95% CI: 0.21,0.84 p=0.001), and impaired left ventricular ejection fractions (LVEF; WMD=-5.84, 95% CI: -9.69, -1.99, p=0.003). Impaired LVEF (WMD=-2.24, 95% CI: -3.32, -1.17, p<0.001) was observed in the CM group.

CONCLUSION

Statistical differences can be observed in some CMRI parameters between patients with myocarditis and healthy controls; however, apart from native T1 mapping, there were no large differences in other parameters between two groups, which may reveal the limited benefit of CMRI in assessing myocarditis in children and adolescents.

Patients with Post-COVID-19 Vaccination Myocarditis Have More Favorable Strain in Cardiac Magnetic Resonance Than Those With Viral Myocarditis

There have been reports of myocarditis following vaccination against COVID-19. We sought to describe cardiac magnetic resonance (CMR) findings among pediatric patients. Retrospective review at a large academic center of patients clinically diagnosed with post-vaccine myocarditis (PVM) undergoing CMR. Data collected included parametric mapping, ventricular function, and degree of late gadolinium enhancement (LGE). Post-processing strain analysis was performed using feature tracking. Strain values, T1/T2 values, and ventricular function were compared to age- and gender-matched controls with viral myocarditis using a Wilcoxon Signed Rank test. Among 12 patients with presumed PVM, 11 were male and 11 presented after the second vaccination dose, typically within 4 days. All presented with chest pain and elevated troponin. 10 met MRI criteria for acute myocarditis. All had LGE typically seen in the lateral and inferior walls; only five had prolonged T1 values. 10 met criteria for edema based on skeletal muscle to myocardium signal intensity ratio and only 5 had prolonged T2 mapping values. Patients with PVM had greater short-axis global circumferential and radial strain, right ventricle function, and cardiac output when compared to those with viral myocarditis. Patients with PVM have greater short-axis global circumferential and radial strains compared to those with viral myocarditis. LGE was universal in our cohort. Signal intensity ratios between skeletal muscle and myocardium may be more sensitive in identifying edema than T2 mapping. Overall, the impact on myocardial strain by CMR is less significant in PVM compared to more classic viral myocarditis.

Leitlinie Myokarditis der Deutschen Gesellschaft für Pädiatrische Kardiologie

This consensus statement presents updated recommendations on diagnosis and treatment of myocarditis in childhood.

Cardiac involvement in pediatric hemolytic uremic syndrome

BACKGROUND

Cardiac involvement is a known but rare complication of pediatric hemolytic uremic syndrome (HUS). We conducted a nationwide observational, retrospective case-control study describing factors associated with the occurrence of myocarditis among HUS patients.

METHODS

Cases were defined as hospitalized children affected by any form of HUS with co-existent myocarditis in 8 French Pediatric Intensive Care Units (PICU) between January 2007 and December 2018. Control subjects were children, consecutively admitted with any form of HUS without coexistent myocarditis, at a single PICU in Lyon, France, during the same time period.

RESULTS

A total of 20 cases of myocarditis were reported among 8 PICUs, with a mean age of 34.3 ± 31.9 months; 66 controls were identified. There were no differences between the two groups concerning the season and the typical, Shiga toxin-producing Escherichia coli (STEC-HUS), or atypical HUS (aHUS). Maximal leukocyte count was higher in the myocarditis group (29.1 ± 16.3G/L versus 21.0 ± 9.9G/L, p = 0.04). The median time between admission and first cardiac symptoms was of 3 days (range 0-19 days), and 4 patients displayed myocarditis at admission. The fatality rate in the myocarditis group was higher than in the control group (40.0% versus 1.5%, p < 0.001). Thirteen (65%) children from the myocarditis group received platelet transfusion compared to 19 (29%) in the control group (p = 0.03).

CONCLUSION

Our study confirms that myocarditis is potentially lethal and identifies higher leukocyte count and platelet transfusion as possible risk factors of myocarditis. A higher resolution version of the Graphical abstract is available as Supplementary information.

The effect of paclitaxel plus carboplatin chemotherapy on subclinical cardiotoxicity in patients with non-small cell lung cancer: A speckle tracking echocardiography-based study

BACKGROUND

Although chemotherapy-induced cardiotoxicity is an emerging problem, limited information is available on the effects of chemotherapy on left ventricular (LV) mechanical functions in patients with non-small cell lung cancer (NSCLC).

OBJECTIVE

We aimed to explore chemotherapy-induced alterations in cardiac mechanical functions in patients with NSCLC using speckle tracking echocardiography (STE).

METHODS

Seventy-one patients with NSCLC and 34 age and sex matched control subjects were consecutively included. Based on their good performance status (Eastern Cooperative Oncology Group performance status), 39 patients were treated with paclitaxel plus carboplatin (PC) regimen and 32 patients were treated with vinorelbine plus cisplatin (VC) regimen. All patients and controls underwent conventional two-dimensional echocardiography and STE at baseline to assess their LV functions. The echocardiographic examinations of NSCLC patients were repeated after the chemotherapy regimens.

RESULTS

None of the NSCLC patients developed any signs or symptoms of clinical heart failure during or after the chemotherapy. There were not any significant differences in LV ejection fraction between NSCLC patients and controls before and after chemotherapy. There were not any significant differences in baseline LV global longitudinal strain (GLS), radial strain (RS), and circumferential strain (CS) between NSCLC patients and controls. However, all LV GLS, RS and CS significantly decreased in patients treated with the PC regimen resulting in a significant difference compared to both VC group and controls while no significant decreases were observed in strain measures in VC group.

CONCLUSION

Paclitaxel plus carboplatin, but not VC, may induce subclinical cardiotoxicity in patients with NSCLC, which may be detected by STE.

Multimodality imaging in acute myocarditis

The diagnosis of acute myocarditis often involves several noninvasive techniques that can provide information regarding volumes, ejection fraction, and tissue characterization. In particular, echocardiography is extremely helpful for the evaluation of biventricular volumes, strain and ejection fraction. Cardiac magnetic resonance, beyond biventricular volumes, strain, and ejection fraction allows to characterize myocardial tissue providing information regarding edema, hyperemia, and fibrosis. Contemporary cardiac computed tomography angiography (CCTA) can not only be extremely important for the assessment of coronary arteries, pulmonary arteries and aorta but also tissue characterization using CCTA can be an additional tool that can explain chest pain with a diagnosis of myocarditis.

Pediatric Myocarditis: What Have We Learnt So Far?

Myocarditis is an inflammatory disease of the myocardium that is troublesome to diagnose and manage, especially in children. Since the introduction of endomyocardial biopsy (EMB), new diagnostic tools have provided useful data. Especially when enhanced with immunohistochemistry and polymerase chain reaction (PCR) studies, EMB remains the gold standard for the diagnosis. Notably, cardiac magnetic resonance (MRI) is a non-invasive tool that can confirm the diagnosis and has a particular usefulness during the follow-up. The causes of myocarditis are heterogeneous (mostly viral in children). The course and outcome of the illness in the pediatric population represent a complex interaction between etiologic agents and the immune system, which is still not fully understood. The clinical presentation and course of myocarditis vary widely from paucisymptomatic illness to acute heart failure refractory to therapy, arrhythmias, angina-like presentation and sudden cardiac death. In this setting, cardiac biomarkers (i.e., troponins and BNP), although unspecific, can be used to support the diagnosis. Finally, the efficacy of therapeutic strategies is controversial and not confirmed by clinical trials. In this review, we summarized the milestones in diagnosis and provided an overview of the therapeutic options for myocarditis in children.

The Diagnostic Role of Echocardiographic Strain Analysis in Patients Presenting with Chest Pain and Elevated Troponin: A Multicenter Study

BACKGROUND

Myocarditis presenting as acute chest pain with elevated troponins without significant cardiac compromise is rare in previously healthy children, often referred to as myopericarditis. Diagnosis is challenging as conventional echocardiographic measures of systolic function can be normal. This study aimed to demonstrate the diagnostic utility of strain imaging in this scenario.

METHODS

This is a multi-center retrospective study including patients presenting with chest pain and elevated troponin from 10 institutions who underwent cardiac MRI (CMR) and transthoracic echocardiogram (echo) within 30 days of each other (group 1). Findings were compared to 19 controls (group 2). Clinical data, conventional echo and CMR data were collected. Echo-derived strain was measured at the core lab. Group 1 was divided into subgroups as CMR myocarditis positive (group 1a) or negative (group 1b) based on established criteria.

RESULTS

Group 1 included 108 subjects (88 in group 1a, 20 in group 1b). While all groups had normal mean fractional shortening (FS) and mean left ventricular ejection fraction (LVEF), group 1 had significantly lower EF (56.8+/-7.0) compared to group 2 ( 62.3+/- 4.9, P<0.005) and FS (31.2+/- 4.9) compared to group 2 (34.1+/-3.5, p<0.05). Additionally, peak global longitudinal strain (GLS%) was markedly abnormal in group 1 (-13.9+/-3.4 ) compared to group 2 (-19.8+/-2.1 , P<0.001). In subgroup analysis, GLS% was markedly abnormal in group 1a (-13.2 ± 3.0%) compared to group 1b (-17.3 ± 2.6% and p<0.001). Fifty-four subjects had follow up echocardiograms (46 in group 1a, 8 in group 1b) with mean follow-up time of 10 months (SD=11 months). At follow up, while EF and FS returned to normal in all patients, abnormalities in strain persisted in group 1, with 22% of them still having abnormal GLS. Moreover, mean GLS was more abnormal in group 1a (-16.1 +/- 2.6) compared to group 1b (-17.4+/- 1.2, p<0.05).

CONCLUSIONS

Our study demonstrates that echo GLS% is significantly worse in subjects with myopericarditis presenting with chest pain and elevated troponins compared to controls even when conventional measures of systolic function are largely normal and that these abnormalities persisted overtime.

Emerging Role of Cardiac Magnetic Resonance Imaging in Diagnosing Myocarditis: A Blunder or The Way To Get the Problem Sorted?

Acute myocarditis is a disease affecting the myocardial tissue, which is caused by infections, rheumatic diseases, especially sarcoidosis, or certain therapies. Its diagnosis may be difficult, owing to its variable clinical presentation. In this setting, cardiac magnetic resonance plays a pivotal role in detecting myocardial inflammation through qualitative, semiquantitative, and quantitative parameters, in particular with the new quantitative techniques such as T1 and T2 mapping, combined or not with late gadolinium enhancement evaluation. This is in accordance with the revised Lake Louise criteria. In this review, the emerging role of the new cutting-edge cardiac magnetic resonance imaging techniques in diagnosing myocarditis is extensively presented.

Usefulness of Left Ventricular Myocardial Deformation in Children Hospitalized for Acute Myocarditis who Develop Arrhythmias

Cardiac arrhythmias occur in 3-40% of patients with acute myocarditis and cause significant morbidity and mortality. Myocardial injury also results in abnormal myocardial deformation. The relationship between left ventricular (LV) deformation, measured by two-dimensional speckle tracking echocardiography (2D-STE), and arrhythmia in pediatric myocarditis is unknown. We evaluated the association between 2D-STE and arrhythmias in children hospitalized with acute myocarditis. We reviewed patients ≤ 18 years hospitalized for acute myocarditis from 2008 to 2018. Arrhythmias were defined as 1) non-sustained or sustained ventricular tachycardia or ventricular fibrillation, 2) sustained supraventricular tachycardia (SVT), 3) high-grade or complete heart block, and 4) any arrhythmia treated with an antiarrhythmic medication. Systolic LV strain values (including LV global longitudinal strain (GLS), global circumferential strain (GCS), and six segments of LV regional long axis strain) were obtained from initial echocardiograms during hospitalization. Of 66 patients hospitalized, 23 (35%) had arrhythmias. SVT was the predominant arrhythmia (74%). Global and regional strain indices were reduced in the arrhythmia group: LV GLS [-8.9 (IQR -13.6, -6.1) vs. -13.7 (IQR -16.9, -9.7), p = 0.038]; basal inferior/septal [-10.7 (IQR -15.5, -7.8) vs. -16.4 (IQR -18, -11.8), p = 0.009]; basal anterior/lateral [-7.1 (IQR -12.8, -4.7) vs. -9.4 (IQR -16.7, -7.4), p = 0.025]; and mid inferior/septal segments [-9 (IQR -13, -7.7) vs. -14.1 (IQR -22.5, -10.7), p = 0.007]. After controlling for age, reductions in GLS and segmental strain in the two basal and two mid-segments were associated with increased arrhythmia occurrence (p <0.05). Our findings suggest that echocardiographic LV deformation by 2D-STE may be useful in identifying pediatric patients with acute myocarditis at risk for arrhythmias.

Diagnosis and Management of Myocarditis in Children: A Scientific Statement From the American Heart Association

Myocarditis remains a clinical challenge in pediatrics. Originally, it was recognized at autopsy before the application of endomyocardial biopsy, which led to a histopathology-based diagnosis such as in the Dallas criteria. Given the invasive and low-sensitivity nature of endomyocardial biopsy, its diagnostic focus shifted to a reliance on clinical suspicion. With the advances of cardiac magnetic resonance, an examination of the whole heart in vivo has gained acceptance in the pursuit of a diagnosis of myocarditis. The presentation may vary from minimal symptoms to heart failure, life-threatening arrhythmias, or cardiogenic shock. Outcomes span full resolution to chronic heart failure and the need for heart transplantation with inadequate clues to predict the disease trajectory. The American Heart Association commissioned this writing group to explore the current knowledge and management within the field of pediatric myocarditis. This statement highlights advances in our understanding of the immunopathogenesis, new and shifting dominant pathogeneses, modern laboratory testing, and use of mechanical circulatory support, with a special emphasis on innovations in cardiac magnetic resonance imaging. Despite these strides forward, we struggle without a universally accepted definition of myocarditis, which impedes progress in disease-targeted therapy.

Detailed Assessment of Left Ventricular Function in Multisystem Inflammatory Syndrome in Children, Using Strain Analysis

Background

Cardiac manifestations in multisystem inflammatory syndrome in children (MIS-C) occur in ∼80% of patients. Left ventricular (LV) systolic dysfunction is the most frequent cardiac finding.

Methods

In this single-centre, retrospective cohort study, we report on detailed assessment of LV function in MIS-C patients using strain and strain rate analysis. We compare those with normal peak systolic strain z-scores (both longitudinal and circumferential strain) to those with abnormal peak systolic strain z-scores (decreased circumferential and/or longitudinal strain).

Results

Among 25 patients, 14 (56%) were male, 20 (80%) were Black or Hispanic, 13 (52%) were overweight/obese, and the median age was 11.4 years (interquartile range: 7.5 to 16). Median ejection fraction (EF) was 55.2% (interquartile range: 48.3% to 58%), with the abnormal strain patients having a lower EF (P < 0.01). Demographics were similar between groups. The abnormal strain patients had more organ systems involved and were more likely to require inotropic support. In a comparison of MIS-C patients with normal EF (n = 15) to controls, MIS-C patients had lower peak systolic strain as well as lower early diastolic strain rates. In patients with initially depressed function, EF normalized in 8 of 10 (80%), but 4 of 11 (36%) patients had persistently abnormal systolic strain after discharge.

Conclusions

LV systolic dysfunction is common in the acute phase of MIS-C, and detection may be improved with strain imaging. Longitudinal cardiac follow-up is imperative, as some patients may be at risk for persistent LV dysfunction.

Scorpion sting: N-terminal fragment of proB-type natriuretic peptide as an early predictor of pediatric cardiotoxicity

AIM OF THE WORK

This prospective study was conducted to evaluate the clinical reliability of N-terminal fragment of proB-type natriuretic peptide (NT-proBNP) in identifying patients with cardiotoxicity in the early hours following scorpion sting.

SUBJECTS AND METHODS

This study involved 483 children aging between 2-17 years who were admitted to Minia University Poisoning Control Center from 1st January 2010 to 31st December 2019 with a history of scorpion sting, and on clinical evaluation symptoms were manifested. All subjects were clinically examined, investigated for NT-proBNP and CPK-MB on admission, 6 h and 24 h post-envenomation; and subjected to 24 h cardiac monitoring with periodic ECG every 6 h.

RESULTS

Assessment of CPK-MB levels showed a significant increase in all moderate to severe cases 6 h post-envenomation. Assessment of NT-proBNP levels showed a significant increase in all moderate to severe cases on admission and 6 h post-envenomation. Moreover, there was a significant decrease in the NT-proBNP level after 24 h compared with that measured on admission. The sensitivity of NT-proBNP for the diagnosis of myocardial injury at hospital admission was significantly higher than that of CPK-MB.

CONCLUSION

NT-proBNP may be a valuable and sensitive laboratory biomarker to predict cardiotoxicity of scorpion sting in the early hours.

Performance of cardiovascular magnetic resonance strain in patients with acute myocarditis

Background

To explore the value of myocardial strain derived from cardiac magnetic resonance (CMR) feature tracking in evaluating left ventricular function in acute myocarditis and its relationship with the left ventricular ejection fraction (LVEF) and late gadolinium enhancement (LGE).

Methods

A total of 115 cases of clinically suspected acute myocarditis, confirmed by CMR, were collected from two centers and divided into groups with reduced and preserved ejection fraction (EF). Fifty normal volunteers were enrolled as the control group. The myocardial strain analysis was based on feature tracking imaging (FTI).

Results

Compared with the control group, the group with myocarditis and preserved EF showed an increased peak ejecting rate (PER), end diastolic volume (EDV), end systolic volume (ESV), stroke volume (SV), EDV index (EDVi), ESV index (ESVi), SV index (SVi) and decreased strain indices. In patient with myocarditis, the group with reduced EF showed increased EDV, ESV, LGE, LGE% and decreased strain indices compared to the group with preserved EF. EF showed good correlation with LGE, PSC, PSSRC (r>0.6). Peak strain circumferential (PSC) showed good correlation with LGE (r=0.62). The AUC of PSC was optimal to detect early left ventricular dysfunction in myocarditis patient with preserved EF using a cutoff of -19.72% (sensitivity of 68% and specificity of 88%).

Conclusions

Myocardial strain analysis using CMR FTI can provide information about early ventricular dysfunction in myocarditis patient with preserved EF. PSC showed best diagnostic performance, and correlated with LGE.

Evaluation of Early Gadolinium Enhancement (EGE) and Cardiac Functional Parameters in Cine-Magnetic Resonance Imaging (MRI) on Artificial Intelligence in Patients with Acute Myocarditis: A Case-Controlled Observational Study

<strong>BACKGROUND</strong> The diagnosis of myocarditis is challenging, and the treatment is generally delayed due to misdiagnosis or missed diagnosis. Endomyocardial biopsy (EMB) is not a specific or sensitive method. A case-controlled observational study was conducted to evaluate early gadolinium enhancement (EGE) and left ventricular functional parameters on Artificial Intelligence in cine-MRI in patients with acute myocarditis. <strong>MATERIAL AND METHODS</strong> We selected 21 patients with pathologically proven acute myocarditis. We analyzed the EGE findings (total/serial number and location of positive-segments using the 17-segment model according to the American Heart Association) and clinical characteristics (symptoms, arrhythmias in ECG, coronary angiography, and EMB). All patients were divided into positive EGE and negative EGE groups to analyze left ventricular functional parameters (LVEF, FS, LVEDD, LVEDV, LVESV, LVMM, LVSV, CO, and CI) on Artificial Intelligence. <strong>RESULTS</strong> We enrolled 21 patients (11 males) with a mean age of 32.6±9.8 years (range, 16 to 51 years). Abnormalities on EGE were found in 2/3 of patients, involving 41 segments among multiple locations on the myocardium. The differences in LVEF (40.2±10.2% <i>vs.</i> 51.3±3.6%), LVESV (69.0±16.1ml <i>vs.</i> 52.5±10.6ml) and LVSV (42.6±11.4 <i>vs.</i> 52.8±2.8 ml) on Artificial Intelligence was statistically significant between the positive EGE and negative EGE groups (p<0.05). <strong>CONCLUSIONS</strong> Our results suggest a significant role of EGE on the basis of Lake Louise criteria in evaluating patients with clinical suspicion of acute myocarditis. Parameters, including LVEF, LVESV, and LVSV, on Artificial Intelligence, may be useful independent predictors for capillary leakage and microcirculatory disturbance in myocarditis.