Incremental value of cardiovascular magnetic resonance feature tracking derived atrial and ventricular strain parameters in a comprehensive approach for the diagnosis of acute myocarditis

Cardiac magnetic resonance feature tracking evaluates left atrial strain in patients with systemic lupus erythematosus and mitral regurgitation

PurposeTo explore left atrial (LA) function in patients with systemic lupus erythematosus (SLE) and mitral regurgitation assessed by cardiac magnetic resonance imaging feature tracking (MRI-FT).MethodIn this study, 64 SLE patients (35.0 ± 12.3 years, 49 females) and 50 age- and gender-matched healthy controls (32.1 ± 11.2 years, 32 females) were analyzed. Patients with SLE were further classified into two subgroups according to mitral regurgitation defined by echocardiography: mitral regurgitation subgroup (n = 32) and non-mitral regurgitation subgroup (n = 32). All subjects underwent cardiac magnetic resonance (CMR) examination and SLE patients underwent extra laboratory testing. LA volume and strain parameters were compared among the three groups, and a correlation analysis was further performed between CMR parameters and clinical variables.ResultsPatients in both mitral regurgitation and non-mitral regurgitation subgroups showed higher LAVmin (29.15 ± 7.5, 26.22 ± 8.23 vs 21.68 ± 7.67, p = .003, .026) and LAVimin (17.44,14.9 vs 12.62, p = .002,.046) than healthy control subjects. Abnormal LA reservoir, conduit and bump strain were also observed in SLE patients (all p < .05), with more severe reservoir (p = .006, .031) and bump strain (p = .01, .033) abnormality found in mitral regurgitation subgroup. In the SLE group, LA reservoir, bump and conduit strain were significantly positively correlated with LVEF (B = 0.467, p < .001 vs B = 0.019, p = .01 vs B = 0.168, p = .001 vs B = 0.036, p < .001 vs B = 0.020, p = .024). Conduit strain (εe, SRe) was positively correlated with LAEF (B = 0.229, p = .032 vs B = 0.027, p = .008).ConclusionMRI-FT based LA parameters may be considered a helpful tool to evaluate LA function in SLE patients, and LA strain may indicate severity of the cardiac dysfunction in SLE patients.

Normal Values for Atrial Deformation Measured by Feature-Tracking Cardiac MRI: A Meta-Analysis

BACKGROUND

A consensus on normal atrial deformation measurements by feature-tracking cardiac MRI remained absent.

PURPOSE

Provide reference ranges for atrial strain parameters in normal subjects, evaluating the influence of field strength and analysis software on the measurements.

STUDY TYPE

Meta-analysis.

POPULATION

2708 subjects from 42 studies undergoing cardiac MRI.

ASSESSMENT

A systematic search was conducted from database (PubMed, Web of Science, ScienceDirect, and EMBASE) inception through August 2023. The random-effects model was used to pool the means of biatrial strain parameters. Heterogeneity and clinical variable effects were assessed. Strain measurements among different field strengths and analysis software were compared.

STATISTICAL TESTS

The inverse-variance method, Cochrane Q statistic, and I2 value, meta-regression analysis, and ANOVA were used; P < 0.05 was considered statistically significant.

RESULTS

The pooled means of left atrial (LA) total strain (εs), passive strain (εe), and active strain (εa) were 37.46%, 22.73%, and 16.24%, respectively, and the pooled means of LA total strain rate (SRs), passive strain rate (SRe), and active strain rate (SRa) were 1.66, -1.95, and -1.83, indicating significant heterogeneity. The pooled means of right atrial (RA) εs, εe, and εa were 44.87%, 26.05%, and 18.83%. RA SRs, SRe, and SRa were 1.66, -1.95, and -1.83, respectively. The meta-regression identified age as significantly associated with LA εs, εe and SRe, field strength was associated with LA SRa (all P < 0.05). ANOVA revealed differences in LA εa and SRa among different analysis software and in LA εs and all LA strain rates (all P < 0.05) among field strengths. No significant differences were identified in RA strain across analysis software (RA strain: P = 0.145-0.749; RA strain rates: P = 0.073-0.744) and field strengths (RA strain: P = 0.641-0.794; RA strain rates: P = 0.204-0.458).

DATA CONCLUSION

This study demonstrated the pooled reference values of biatrial strain. Age, analysis software, and field strength were attributed to differences in LA strain, whereas RA strain showed consistency across different field strengths and analysis software. Limited study subjects may account for the absence of influence on RA strain.

LEVEL OF EVIDENCE: 1

TECHNICAL EFFICACY

Stage 5.

Diagnostic performance and relationships of structural parameters and strain components for the diagnosis of cardiac amyloidosis with MRI

PURPOSE

The purpose of this study was to evaluate the diagnostic performance and relationships of cardiac MRI structural parameters and strain components in patients with cardiac amyloidosis (CA) and to estimate the capabilities of these variables to discriminate between CA and non-amyloid cardiac hypertrophy (NACH).

MATERIALS AND METHODS

Seventy patients with CA (56 men; mean age, 76 ± 10 [standard deviation] years) and 32 patients (19 men; mean age, 63 ± 10 [standard deviation] years) with NACH underwent cardiac MRI. Feature tracking (FT) global longitudinal strain (GLS), radial strain (GRS), circumferential strain (GCS), strain AB ratio (apical strain divided by basal strain), myocardial T1, myocardial T2 and extracellular volume (ECV) were calculated. Comparisons between patients with CA and those with NACH were made using Mann-Whitney rank sum test. The ability of each variable to discriminate between CA and NACH was estimated using area under the receiver operating characteristic curve (AUC).

RESULTS

Patients with CA had higher median GLS (-7.0% [Q1, -9.0; Q3, -5.0]), higher median GCS (-12.0% [Q1, -15.0; Q3, -9.0]), and lower median GRS (16.5% [Q1, 13.0; Q3, 23.0]) than those with NACH (-9.0% [Q1, -11.0; Q3, -8.0]; -17.0% [Q1, -20.0; Q3, -14.0]; and 25.5% [Q1, 16.0; Q3, 31.5], respectively) (P < 0.001 for all). Median myocardial T1 and ECV were significantly higher in patients with CA (1112 ms [Q1, 1074; Q3, 1146] and 47% [Q1, 41; Q3, 55], respectively) than in those with NACH (1056 ms [Q1, 1011; Q3, 1071] and 28% [Q1, 26; Q3, 30], respectively) (P < 0.001). Basal ECV showed the best performance for the diagnosis of CA (AUC = 0.975; 95% confidence interval [CI]: 0.947-1). No differences in AUC were found between AB ratio of GRS (0.843; 95% CI: 0.768-0.918) and basal myocardial T1 (0.834; 95% CI: 0.741-0.928) for the diagnosis of CA (P = 0.81). The combination of the AB ratio of FT-GRS and basal myocardial T1 had a diagnostic performance not different from that of basal ECV (P = 0.06).

CONCLUSION

ECV outperforms FT-strain for the diagnosis of CA with cardiac MRI. The AB ratio of FT-GRS associated with myocardial T1 provides diagnostic performance similar to that achieved by ECV.

Three-Dimensional Feature Tracking Study of Healthy Chinese Ventricle by Cardiac Magnetic Resonance

PURPOSE

Myocardial strain, as a crucial quantitative indicator of myocardial deformation, can detect the changes of cardiac function earlier than parameters such as ejection fraction (EF). It has reported that cardiac magnetic resonance(CMR) and post-processing software possess the ability to obtain the stability and repeatability strain values. Recently, the normal strain values range of people are debatable, especially in the Chinese population. Therefore, we aim to explore the ventricular characteristics and the myocardial strain values of the Chinese people by using the cardiac magnetic resonance feature tracking (CMR-FT). Additionally, we attempted to use the myocardial and chordae tendineae contours to calculate the ventricular volumes by the CMR-FT. This study may provide valuable insights into the application of CMR-FT in tracking the ventricular characteristics and myocardial strain for Chinese population, especially in suggesting an referable myocardial strain parameters of the Chinese.

METHODS

A total of 109 healthy Chinese individuals (age range: 18 to 58 years; 52 males and 57 females) underwent 3.0T CMR to acquire the cardiac images. The commercial post-processing software was employed to analyse the image sequence by semi-automatic processing, then the biventricular morphology (End-Diastolic Volume, EDV; EDV/Body Surface Area, EDV/BSA), function(EF; Cardiac Output, CO; Cardiac Index, CI) and strain(Radial Strain, RS; Circumferential Strain, CS; Longitudinal Strain, LS) values were obtained.The biventricular myocardial strain values were stratified according to the age and gender. The Left Ventricular( LV base, mid, apex) and myocardial strain values of three coronary artery areas were calculated based on the the strain value of LV American Heart Association(AHA) 16 segments.

RESULTS

It was shown that the females had larger LV globe strain values compared with the males (LVGPRS: 42.0 ± 8.5 versus 33.6 ± 6.2%, P < 0.001; LVGPCS: -21.2 ± 2.1 versus - 19.7 ± 2.3%, P < 0.001; LVGPLS: -16.4 ± 2.6 versus - 14.6 ± 2.2%, P < 0.001;). Moreover, the differences in RS, CS, and LS among the LV myocardium 16 segments were obvious. However, the right ventricle (RV) strain values showed non-normal distribution in the volunteers of this research.

CONCLUSIONS

Here, we successfully tracked the characteristics of bilateral ventricles in healthy Chinese populations through using the 3.0T CMR. We confirmed that there was a gender difference in LV Globe Strain values. In addition, we obtained strain values for each myocardial segment of the LV and different coronary artery regions based on the AHA 16 segments method, Our results also showed that the RV strain values with a non-normal distribution, and RV global strain values were not related to the gender and age. Furthermore, LVGPRS, LVGPLS, and RVGPRS were significantly correlated with BMI, CO, CI, and EDV in the Chinese population.

Unveiling the Diagnostic Value of Strain Parameters Across All 4 Cardiac Chambers in Patients With Acute Myocarditis With Varied Ejection Fraction: A Cardiovascular Magnetic Resonance Feature-Tracking Approach

BACKGROUND

This study assesses the diagnostic utility of strain parameters from cardiovascular magnetic resonance feature tracking across all cardiac chambers in patients with acute myocarditis, stratified by ejection fraction.

METHODS AND RESULTS

Our cohort included 65 patients with acute myocarditis and 25 healthy controls; all underwent cardiac magnetic resonance imaging. Patients were divided into 2 groups based on left ventricular ejection fraction (EF)with a 55% cutoff: acute myocarditis with preserved EF, EF ≥55%, n=48; and acute myocarditis with reduced EF, EF <55%, n=17. The control group matched for age and sex. Cardiovascular magnetic resonance feature tracking evaluated strain parameters across all cardiac chambers. Both acute myocarditis with preserved EF and acute myocarditis with reduced EF groups showed significant decreases in left atrial peak early negative strain rate compared with controls. The acute myocarditis with reduced EF group had significantly reduced left ventricular circumferential strain relative to acute myocarditis with preserved EF and controls. Receiver operating characteristic curve analysis confirmed the diagnostic accuracy in distinguishing patients with acute myocarditis with preserved EF from controls, with left atrial peak early negative strain rate achieving 92.9% specificity, left ventricular circumferential strain demonstrating an area under the curve of 0.832, and similarly effective results for left ventricular longitudinal strain and right ventricular longitudinal strain. Additionally, left atrial peak early negative strain rate and left ventricular circumferential strain showed significant correlations with troponin I levels, indicating myocardial injury.

CONCLUSIONS

Cardiovascular magnetic resonance feature-tracking-derived strain parameters, particularly left atrial peak early negative strain rate and left ventricular circumferential strain, effectively diagnose acute myocarditis across different EFs, enhancing diagnostic accuracy and facilitating early detection, notably in patients with preserved EF.

Application of left atrial strain derived from cardiac magnetic resonance feature tracking to predict cardiovascular disease: A comprehensive review

The structural and functional changes of the left atrium (LA)are important for maintaining the filling of the left ventricle (LV), whether the hemodynamics is stable or not, and are valuable for evaluating LV diastolic dysfunction and grading the severity. Studies over the past decade have shown that LA structural alterations are linked to several cardiovascular disorders, and LA enlargement has been identified as a strong predictor of several cardiovascular diseases. However, LA structural or volumetric abnormalities are commonly seen in the advanced stages of disease and do not adequately represent functional changes throughout the cardiac cycle. In recent years, LA strain obtained using cardiac magnetic resonance feature tracking (CMR-FT)technology has been shown to provide early monitoring of LA tension damage while also comprehensively reflecting LA functional changes in three phases, providing deeper insights into cardiovascular disease risk, prognosis of cardiovascular disease, and evaluation of therapeutic efficacy. When compared to the ultrasound speckle tracking approach, the CMR-FT technique provides improved spatial resolution, repeatability, and reproducibility. We report a comprehensive review of the most recent studies on CMR-LA strain in the past five years, including normal reference values, early detection of disease, incremental diagnosis, improvement of risk stratification, assessment of the value of atrial-ventricular hemodynamics and coupled injury, major adverse cardiovascular events and prognostic value, as well as future research perspectives and current limitations, aiming at providing an objective reference for the further exploration of the value of the application of CMR-LA strain in various cardiac disorders.

Cardiac MRI-Enriched Phenomapping Classification and Differential Treatment Outcomes in Patients With Ischemic Cardiomyopathy

BACKGROUND

Significant controversy continues to confound patient selection and referral for revascularization and mitral valve intervention in patients with ischemic cardiomyopathy (ICM). Cardiac magnetic resonance (CMR) enables comprehensive phenotyping with gold-standard tissue characterization and volumetric/functional measures. Therefore, we sought to determine the impact of CMR-enriched phenomapping patients with ICM to identify differential outcomes following surgical revascularization and surgical mitral valve intervention (sMVi).

METHODS

Consecutive patients with ICM referred for CMR between 2002 and 2017 were evaluated. Latent class analysis was performed to identify phenotypes enriched by comprehensive CMR assessment. The primary end point was death, heart transplant, or left ventricular assist device implantation. A multivariable Cox survival model was developed to determine the association of phenogroups with overall survival. Subgroup analysis was performed to assess the presence of differential response to post-magnetic resonance imaging procedural interventions.

RESULTS

A total of 787 patients were evaluated (63.0±11.2 years, 24.8% women), with 464 primary events. Subsequent surgical revascularization and sMVi occurred in 380 (48.3%) and 157 (19.9%) patients, respectively. Latent class analysis identified 3 distinct clusters of patients, which demonstrated significant differences in overall outcome (P<0.001). Latent class analysis identified differential survival benefit of revascularization in patients as well as patients who underwent revascularization with sMVi, based on phenogroup classification, with phenogroup 3 deriving the most survival benefit from revascularization and revascularization with sMVi (hazard ratio, 0.61 [0.43-0.88]; P=0.0081).

CONCLUSIONS

CMR-enriched unsupervised phenomapping identified distinct phenogroups, which were associated with significant differential survival benefit following surgical revascularization and sMVi in patients with ICM. Phenomapping provides a novel approach for patient selection, which may enable personalized therapeutic decision-making for patients with ICM.

Effect of late gadolinium enhancement on left atrial impairment in myocarditis patients

OBJECTIVE

The aims of our study were to investigate the effect of the extent and location of late gadolinium enhancement (LGE) on the left atrium (LA) function in patients with acute myocarditis (AM) using cardiovascular magnetic resonance (CMR).

METHOD

This retrospective study performed CMR scans in 113 consecutive patients (89 males, 24 females; mean age 45.8 ± 17.3 years) with AM that met the updated Lake Louise criteria. Reservoir, conduit, and booster LA functions were analyzed by CMR feature tracking using dedicated software. Besides LA strain measurements, myocardial scar location and extent were assigned and quantified by LGE imaging.

RESULTS

AM patients with septal LGE had impaired reservoir, conduit, and conduit strain rate function in comparison with AM patients with non-septal LGE (p = 0.001, for all). In fully adjusted multivariable linear regression, reservoir and conduit were significantly associated with left ventricle (LV) LGE location (β coefficient = 8.205, p = 0.007; β coefficient = 5.185, p = 0.026; respectively). In addition, LA parameters decreased according to the increase in the extent of LV fibrosis (LGE ≤ 10%; LGE 11-19%; LGE ≥ 20%). After adjustment in multivariable linear regression, the association with LV LGE extent was no longer statistically significant.

CONCLUSION

In patients with acute myocarditis, LA function abnormalities are significantly associated with LV LGE location, but not with LGE extent. Septal LGE is paralleled by a deterioration of LA reservoir and conduit function.

CLINICAL RELEVANCE STATEMENT

Left atrium dysfunction is associated with the presence of late gadolinium enhancement in the left ventricle septum and can be useful in the clinical prognostication of patients with acute myocarditis, allowing individually tailored treatment.

KEY POINTS

• Myocardial fibrosis is related to atrial impairment. • The location of myocardial fibrosis is the main determinant of atrial dysfunction in myocarditis patients. • The quantification of atrial mechanisms may provide more in-depth insight into myocarditis pathophysiology.

Atrial and Ventricular Strain Imaging Using CMR in the Prediction of Ventricular Arrhythmia in Patients with Myocarditis

(1) Objective: Myocarditis can be associated with ventricular arrhythmia (VA), individual non-invasive risk stratification through cardiovascular magnetic resonance (CMR) is of great clinical significance. Our study aimed to explore whether left atrial (LA) and left ventricle (LV) myocardial strain serve as independent predictors of VA in patients with myocarditis. (2) Methods: This retrospective study evaluated CMR scans in 141 consecutive patients diagnosed with myocarditis based on the updated Lake Louise criteria (29 females, mean age 41 ± 20). The primary endpoint was VA; this encompassed ventricular fibrillation, sustained ventricular tachycardia, nonsustained ventricular tachycardia, and frequent premature ventricular complexes. LA and LV strain function were performed on conventional cine SSFP sequences. (3) Results: After a median follow-up time of 23 months (interquartile range (18-30)), 17 patients with acute myocarditis reached the primary endpoint. In the multivariable Cox regression analysis, LA reservoir (hazard ratio [HR] and 95% confidence interval [CI]: 0.93 [0.87-0.99], p = 0.02), LA booster (0.87 95% CI [0.76-0.99], p = 0.04), LV global longitudinal (1.26 95% CI [1.02-1.55], p = 0.03), circumferential (1.37 95% CI [1.08-1.73], p = 0.008), and radial strain (0.89 95% CI [0.80-0.98], p = 0.01) were all independent determinants of VA. Patients with LV global circumferential strain > -13.3% exhibited worse event-free survival compared to those with values ≤ -13.3% (p < 0.0001). (4) Conclusions: LA and LV strain mechanism on CMR are independently associated with VA events in patients with myocarditis, independent to LV ejection fraction, and late gadolinium enhancement location. Incorporating myocardial strain parameters into the management of myocarditis may improve risk stratification.

Characterization of Subclinical Cardiac Dysfunction by Speckle Tracking Echocardiography in Patients With Non-severe Acute-Phase Myocarditis

Subclinical changes in left ventricular (LV) function have been demonstrated in patients with acute-phase myocarditis (AM) despite normal LV ejection fraction. The impact of AM on right ventricular (RV) and left atrial (LA) function has not been well described. This study aimed to assess for subclinical chamber dysfunction by speckle tracking echocardiography and its clinical relevance in this population. Patients with a diagnosis of AM (as per the European Society of Cardiology Working Group on Myocardial and Pericardial Diseases) admitted to our institution from 2013 to 2018 were assessed. Patients with elevated serum troponin, normal coronary assessment, and normal LV ejection fraction on transthoracic echocardiogram were included. Clinical and echocardiographic parameters were compared with healthy age-, gender- and risk-factor matched controls. Global longitudinal strain assessed through speckle tracking echocardiography was performed using vendor independent software (v4.6; TomTec Arena, Munich, Germany). The final cohort consisted of 80 patients (40 AM patients and 40 controls). No significant differences in baseline clinical characteristics were observed between groups. Of the echocardiographic parameters, AM patients had lower LV-global longitudinal strain (p <0.01), lower RV free-wall strain (p = 0.02) and lower peak LA strain (p <0.01). There were no differences in traditional echocardiographic measures of LV, RV, and LA function appreciated between groups. The presence of multichamber involvement was associated with peak Troponin levels (p <0.01). In conclusion, our study demonstrates the presence of global subclinical myocardial dysfunction in patients with AM. Additionally, the presence of multichamber involvement was significantly associated with degree of myocardial necrosis.

Left Atrial Strain Derived From Cardiac Magnetic Resonance Imaging Can Predict Outcomes of Patients With Acute Myocarditis

OBJECTIVE

There is increasing recognition that left atrial (LA) strain can be a prognostic marker of various cardiac diseases. However, its prognostic value in acute myocarditis remains unclear. Therefore, this study aimed to evaluate whether cardiovascular magnetic resonance (CMR)-derived parameters of LA strain can predict outcomes in patients with acute myocarditis.

MATERIALS AND METHODS

We retrospectively analyzed the data of 47 consecutive patients (44.2 ± 18.3 years; 29 males) with acute myocarditis who underwent CMR in 13.5 ± 9.7 days (range, 0-31 days) of symptom onset. Various parameters, including feature-tracked CMR-derived LA strain, were measured using CMR. The composite endpoints included cardiac death, heart transplantation, implantable cardioverter-defibrillator or pacemaker implantation, rehospitalization following a cardiac event, atrial fibrillation, or embolic stroke. The Cox regression analysis was performed to identify associations between the variables derived from CMR and the composite endpoints.

RESULTS

After a median follow-up of 37 months, 20 of the 47 (42.6%) patients experienced the composite events. In the multivariable Cox regression analysis, LA reservoir and conduit strains were independent predictors of the composite endpoints, with an adjusted hazard ratio per 1% increase of 0.90 (95% confidence interval [CI], 0.84-0.96; P = 0.002) and 0.91 (95% CI, 0.84-0.98; P = 0.013), respectively.

CONCLUSION

LA reservoir and conduit strains derived from CMR are independent predictors of adverse clinical outcomes in patients with acute myocarditis.

Strain Echocardiography in Acute COVID-19 and Post-COVID Syndrome: More than Just a Snapshot

Speckle-tracking echocardiography (STE) has become an established, widely available diagnostic method in the past few years, making its value clear in cases of COVID-19 and the further course of the disease, including post-COVID syndrome. Since the beginning of the pandemic, many studies have been published on the use of STE in this condition, enabling, on the one hand, a better understanding of myocardial involvement in COVID-19 and, on the other, a better identification of risk to patients, although some questions remain unanswered in regard to specific pathomechanisms, especially in post-COVID patients. This review takes a closer look at current findings and potential future developments by summarising the extant data on the use of STE, with a focus on left and right ventricular longitudinal strain.

Left atrial strain parameters derived by echocardiography are impaired in patients with acute myocarditis and preserved systolic left ventricular function

PURPOSE

Data derived by cardiac magnetic resonance (CMR) feature tracking suggest that not only left ventricular but also left atrial function is impaired in patients with acute myocarditis. Therefore, we investigated the diagnostic value of speckle tracking echocardiography of the left ventricle and left atrium in patients with acute myocarditis and normal left ventricular ejection fraction (LVEF).

METHODS AND RESULTS

30 patients with acute myocarditis confirmed by CMR according to the Lake Louise criteria and 20 healthy controls were analyzed including global longitudinal strain (GLS) and left atrial (LA) strain parameters. Although preserved LVEF was present in both groups, GLS was significantly lower in patients with acute myocarditis (GLS - 19.1 ± 1.8% vs. GLS - 22.1 ± 1.7%, p < 0.001). Further diastolic dysfunction measured by E/e' mean was significantly deteriorated in the myocarditis group compared to the control group (E/e' mean 6.4 ± 1.6 vs. 5.5 ± 1.0, p = 0.038). LA reservoir function (47.6 ± 10.4% vs. 55.5 ± 10.8%, p = 0.013) and LA conduit function (-33.0 ± 9.6% vs. -39.4 ± 9.5%, p = 0.024) were significantly reduced in patients with acute myocarditis compared to healthy controls. Also left atrial stiffness index (0.15 ± 0.05 vs. 0.10 ± 0.03, p = 0.003) as well as left atrial filling index (1.67 ± 0.47 vs. 1.29 ± 0.34, p = 0.004) were deteriorated in patients with myocarditis compared to the control group.

CONCLUSION

In patients with acute myocarditis and preserved LVEF not only GLS but also LA reservoir function, LA conduit function and left atrial stiffness index as well as left atrial filling index were impaired compared to healthy controls indicating ventricular diastolic dysfunction and elevated LV filling pressures.

Machine learning approach in diagnosing Takotsubo cardiomyopathy: The role of the combined evaluation of atrial and ventricular strain, and parametric mapping

BACKGROUND

Cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) is a key diagnostic tool in the differential diagnosis between non-ischemic cause of cardiac chest pain. Some patients are not eligible for a gadolinium contrast-enhanced CMR; in this scenario, the diagnosis remains challenging without invasive examination. Our purpose was to derive a machine learning model integrating some non-contrast CMR parameters and demographic factors to identify Takotsubo cardiomyopathy (TTC) in subjects with cardiac chest pain.

MATERIAL AND METHODS

Three groups of patients were retrospectively studied: TTC, acute myocarditis, and healthy controls. Global and regional left ventricular longitudinal, circumferential, and radial strain (RS) analysis included were assessed. Reservoir, conduit, and booster bi-atrial functions were evaluated by tissue-tracking. Parametric mapping values were also assessed in all the patients. Five different tree-based ensemble learning algorithms were tested concerning their ability in recognizing TTC in a fully cross-validated framework.

RESULTS

The CMR-based machine learning (ML) ensemble model, by using the Extremely Randomized Trees algorithm with Elastic Net feature selection, showed a sensitivity of 92% (95% CI 78-100), specificity of 86% (95% CI 80-92) and area under the ROC of 0.94 (95% CI 0.90-0.99) in diagnosing TTC. Among non-contrast CMR parameters, the Shapley additive explanations analysis revealed that left atrial (LA) strain and strain rate were the top imaging markers in identifying TTC patients.

CONCLUSIONS

Our study demonstrated that using a tree-based ensemble learning algorithm on non-contrast CMR parameters and demographic factors enables the identification of subjects with TTC with good diagnostic accuracy.

TRANSLATIONAL OUTLOOK

Our results suggest that non-contrast CMR features can be implemented in a ML model to accurately identify TTC subjects. This model could be a valuable tool for aiding in the diagnosis of subjects with a contraindication to the contrast media. Furthermore, the left atrial conduit strain and strain rate were imaging markers that had a strong impact on TTC identification. Further prospective and longitudinal studies are needed to validate these findings and assess predictive performance in different cohorts, such as those with different ethnicities, and social backgrounds and undergoing different treatments.

Prognostic Significance of Cardiac Magnetic Resonance in Left Atrial and Biventricular Strain Analysis during the Follow-Up of Suspected Myocarditis

To assess the variation in left atrial (LA) and biventricular strain and its prognostic value in the course of suspected myocarditis, this retrospective study included 55 patients with clinically suspected myocarditis who underwent cardiac magnetic resonance (CMR) examinations at baseline and follow-up periods. Cine images were used for feature tracking analysis. Paired Student's t test, McNemar's test, and Cox proportional hazard regression were used for statistical analysis. The LA total emptying fraction was the only functional index that showed a statistically significant improvement. The initial LA peak's late negative strain rate (SRa) was the only parameter with a significant predictive power of major adverse cardiac events under univariable (hazard ratio [HR] 2.396, 95% confidence interval [CI] 1.044-5.498, p = 0.039) and multivariable Cox survival analysis when adjusted by LA strain parameters (HR 5.072, 95% CI 1.478-17.404, p = 0.010), LA strain and functional parameters (HR 7.197, 95% CI 1.679-30.846, p = 0.008), and LA and biventricular strain and functional parameters (HR 10.389, 95% CI 2.250-47.977, p = 0.003). Thus, our findings indicate that CMR strain is useful for monitoring LA and ventricular function in suspected myocarditis, that LA function may recover preceding ventricular function changes, and that LA strain may serve as an incremental tool to predict adverse outcomes.

Feature tracking strain analysis detects the onset of regional diastolic dysfunction in territories with acute myocardial injury induced by transthoracic electrical interventions

Electric interventions are used to terminate arrhythmia. However, myocardial injury from the electrical intervention can follow unique pathways and it is unknown how this affects regional ventricular function. This study investigated the impact of transthoracic electrical shocks on systolic and diastolic myocardial deformation. Ten healthy anaesthetized female swine received five transthoracic shocks (5 × 200 J) and six controls underwent a cardiovascular magnetic resonance exam prior to and 5 h after the intervention. Serial transthoracic shocks led to a global reduction in both left (LV, - 15.6 ± 3.3% to - 13.0 ± 3.6%, p < 0.01) and right ventricular (RV, - 16.1 ± 2.3% to - 12.8 ± 4.2%, p = 0.03) peak circumferential strain as a marker of systolic function and to a decrease in LV early diastolic strain rate (1.19 ± 0.35/s to 0.95 ± 0.37/s, p = 0.02), assessed by feature tracking analysis. The extent of myocardial edema (ΔT1) was related to an aggravation of regional LV and RV diastolic dysfunction, whereas only RV systolic function was regionally associated with an increase in T1. In conclusion, serial transthoracic shocks in a healthy swine model attenuate biventricular systolic function, but it is the acute development of regional diastolic dysfunction that is associated with the onset of colocalized myocardial edema.

Atrial Impairment as a Marker in Discriminating Between Takotsubo and Acute Myocarditis Using Cardiac Magnetic Resonance

PURPOSE

The purpose of this study was to comprehensively compare the left and right atrium strain and strain rate (SR) parameters by cardiac magnetic resonance (CMR) between patients with Takotsubo (TS) and patients with acute myocarditis (AM).

MATERIALS AND METHODS

We retrospectively enrolled 3 groups of patients: TS (n=18), AM (n=14), and 11 healthy subjects. All the patients had complete CMR data for features tracking assessment.Differences in reservoir, conduit strain (εe), conduit strain rate (SRe), and booster phase of biatrial strain were analyzed between the groups using analysis of variance and multivariate analysis of covariance analyses. Intraobserver and interobserver reproducibility was assessed for all strain and SR parameters using intraclass correlation coefficients and Bland-Altman analysis.

RESULTS

Atrial strain was feasible in all patients and controls. In TS, left atrium (LA) reservoir strain (εs), reservoir SR, εe, and SRe were significantly lower compared with the other groups (P=0,001 for all). multivariate analysis of covariance analysis showed association of these parameters after correction for age and sex, while LA booster deformation (εa and SRa) strain parameters were preserved. LA SRe proved to have excellent sensitivity in differentiating patients with TS from those with AM (areas under the curves of 0.903, 95% confidence interval: 0.81-0.99).Biatrial strain and SR parameters showed good (excellent) intraobserver and interobserver reproducibility (ranged between 0.61 to 0.96 and 0.50 to 0.90, respectively).

CONCLUSION

Compared with AM, patients with TS showed significantly decreased LA reservoir, conduit strain, and SR parameters. Therefore, LA strain assessment may have a role in discriminating between TS and AM.

Feature tracking cardiovascular magnetic resonance reveals recovery of atrial function after acute myocarditis

Follow-up after acute myocarditis is important to detect persisting myocardial dysfunction. However, recovery of atrial function has not been evaluated after acute myocarditis so far. Thirty-five patients with strictly defined acute myocarditis underwent cardiovascular magnetic resonance (CMR, 1.5 T) in the acute stage at baseline (BL) and at 3 months follow-up (FU). The study population included 13 patients with biopsy-proven "cardiomyopathy-like" myocarditis (CLM) and 22 patients with "infarct-like" (ILM) clinical presentation. CMR feature tracking (FT) was performed on conventional cine SSFP sequences. Median LA-GLS increased from 33.2 (14.5; 39.2) at BL to 37.0% (25.2; 44.1, P = 0.0018) at FU in the entire study population. Median LA-GLS also increased from 36.7 (26.5; 42.3) at BL to 41.3% (34.5; 44.8, P = 0.0262) at FU in the ILM subgroup and from 11.3 (6.4; 21.1) at BL to 21.4% (14.2; 30.7, P = 0.0186) at FU in the CLM subgroup. Median RA-GLS significantly increased from BL with 30.8 (22.5; 37.0) to FU with 33.7% (26.8; 45.4, P = 0.0027) in the entire study population. Median RA-GLS also significantly increased from 32.7 (25.8; 41.0) at BL to 35.8% (27.7; 48.0, P = 0.0495) at FU in the ILM subgroup and from 22.8 (13.1; 33.9) at BL to 31.0% (26.0; 40.8, P = 0.0266) at FU in the CLM subgroup. Our findings demonstrate recovery of LA and RA function by CMR-FT strain analyses in patients after acute myocarditis independent from clinical presentation. Monitoring of atrial strain could be an important tool for an individual assessment of healing after acute myocarditis.

Cardiovascular Imaging in Cardio-Oncology: The Role of Echocardiography and Cardiac MRI in Modern Cardio-Oncology

Cardiovascular (CV) events are an increasingly common limitation of effective anticancer therapy. Over the last decade imaging has become essential to patients receiving contemporary cancer therapy. Herein we discuss the current state of CV imaging in cardio-oncology. We also provide a practical apparatus for the use of imaging in everyday cardiovascular care of oncology patients to improve outcomes for those at risk for cardiotoxicity, or with established cardiovascular disease. Finally, we consider future directions in the field given the wave of new anticancer therapies.

Role of cardiac MRI in the diagnosis of immune checkpoint inhibitor-associated myocarditis

Immune Checkpoint Inhibitor (ICI)-induced cardiotoxicity is a rare immune-related adverse event (irAE) characterized by a high mortality rate. From a pathological point of view, this condition can result from a series of causes, including binding of ICIs to target molecules on non-lymphocytic cells, cross-reaction of T lymphocytes against tumor antigens with off-target tissues, generation of autoantibodies, and production of pro-inflammatory cytokines. The diagnosis of ICI-induced cardiotoxicity can be challenging, and cardiac magnetic resonance (CMR) represents the diagnostic tool of choice in clinically stable patients with suspected myocarditis. CMR is gaining a central role in diagnosis and monitoring of cardiovascular damage in cancer patients, and it is entering international cardiology and oncology guidelines. In this narrative review, we summarized the clinical aspects of ICI-associated myocarditis, highlighting its radiological aspects and proposing a novel algorithm for the use of CMR.

The utility of cardiac magnetic resonance imaging in the diagnosis of adult patients with acute myocarditis: A systematic review and meta-analysis

BACKGROUND

The presence of myocardial late gadolinium enhancement (LGE) indicates myocyte necrosis, and assists with the diagnosis of acute myocarditis (AM). Cardiac magnetic resonance (CMR) measures other than LGE i.e. tissue characterization and myocardial structural and functional parameters, play an important diagnostic role in assessment for inflammation, as seen in AM. The aim of this systematic review was to appraise the evidence for the use of quantitative CMR measures to identify myocardial inflammation in order to diagnose of AM in adult patients.

METHODS

A systematic literature search of medical databases was performed using PRISMA principles to identify relevant CMR studies on AM in adults (2005-2020; English; PROSPERO registration CRD42020180605). Data for a range of quantitative CMR measures were extracted. Continuous variables with low heterogeneity were meta-analyzed using a random-effects model for overall effect size measured as the standard mean difference (SMD).

RESULTS

Available data from 25 studies reporting continuous quantitative 1.5 T CMR measures revealed that AM is most reliably differentiated from healthy controls using T1 mapping (SMD 1.80, p < 0.01) and T2 mapping (SMD 1.63, p < 0.01), respectively. All other measures examined including T2-weighted ratio, extracellular volume, early gadolinium enhancement ratio, right ventricular ejection fraction, and LV end-diastolic volume, mass, ejection fraction, longitudinal strain, circumferential strain, and radial strain also had discriminatory ability although with smaller standard mean difference values (|SMD| 0.32-0.96, p < 0.01 for all).

CONCLUSIONS

Meta-analysis shows that myocardial tissue characterization (T1 mapping>T2 mapping) followed by measures of left ventricular structure and function demonstrate diagnostic discriminatory ability in AM.

Layer-specific Strain Analysis with Cardiac MRI Feature Tracking in Acute Myocarditis

PURPOSE

To evaluate the diagnostic performance of layer-specific cardiac MRI feature-tracking (FT) strain analysis in patients with acute myocarditis.

MATERIALS AND METHODS

Seventy patients (mean age, 43 years ± 19 [SD]; 46 men) with clinically defined acute myocarditis and 42 healthy controls who underwent cardiac MRI from March 2014 to November 2018 were retrospectively analyzed. FT-based left ventricular peak systolic global longitudinal strain (GLS) and global circumferential strain (GCS) were assessed at subendocardial, midmyocardial, and subepicardial layers. The 2018 Lake Louise criteria (LLC) were assessed. Patients with myocarditis were dichotomized into two groups: those with preserved and those with reduced ejection fraction. For statistical analysis, unpaired t test, one-way analysis of variance, Pearson correlation, and receiver operating characteristic analysis were used.

RESULTS

GLS and GCS values of all layers (eg, midmyocardial GCS: -21.3% ± 5.5 vs -28.0% ± 4.3; P < .001) were impaired in patients with myocarditis compared with controls. Only subepicardial GLS (-20.0% ± 3.3 vs -17.5% ± 3.3; P < .001) and midmyocardial GCS values (-28.0% ± 4.3 vs -23.1% ± 4.3; P < .001) could differentiate between controls and patients with preserved ejection fraction. Midmyocardial GCS correlated with inflammatory myocardial parameters (eg, late gadolinium enhancement percentage, r = 0.48, P < .001). Midmyocardial GCS (area under the receiver operating characteristic curve [AUC], 0.82) and subepicardial GLS (AUC, 0.77) had the highest diagnostic performance for acute myocarditis diagnosis (P < .05 against all other strain parameters). The diagnostic performance of the 2018 LLC was significantly improved by inclusion of these two strain parameters (AUC, 0.92 vs 0.97; P = .04).

CONCLUSION

Diagnostic performance of cardiac MRI FT strain was different between myocardial layers in acute myocarditis, with midmyocardial GCS and subepicardial GLS providing the highest diagnostic performance.Keywords: MRI, Cardiac, Heart, Left Ventricle, Inflammation, Tissue Characterization, MR-Functional Imaging, Feature-Tracking Strain, Acute Myocarditis Supplemental material is available for this article. © RSNA, 2022.

The emerging role of atrial strain assessed by cardiac MRI in different cardiovascular settings: an up-to-date review

The left atrium (LA) has a crucial function in maintaining left ventricular filling, which is responsible for about one-third of all cardiac filling. A growing body of evidence shows that LA is involved in several cardiovascular diseases from a clinical and prognostic standpoint. LA enlargement has been recognized as a predictor of the outcomes of many diseases. However, LA enlargement itself does not explain the whole LA's function during the cardiac cycle. For this reason, the recently proposed assessment of atrial strain at advanced cardiac magnetic resonance (CMR) enables the usual limitations of the sole LA volumetric measurement to be overcome. Moreover, the left atrial strain impairment might allow several cardiovascular diseases to be detected at an earlier stage. While traditional CMR has a central role in assessing LA volume and, through cine sequences, a marginal role in evaluating LA function, feature tracking at advanced CMR (CMR-FT) has been increasingly confirmed as a feasible and reproducible technique for assessing LA function through strain. In comparison to atrial function evaluations via speckle tracking echocardiography, CMR-FT has a higher spatial resolution, larger field of view, and better reproducibility. In this literature review on atrial strain analysis, we describe the strengths, limitations, recent applications, and promising developments of studying atrial function using CMR-FT in clinical practice. KEY POINTS: • The left atrium has a crucial function in maintaining left ventricular filling; left atrial size has been recognized as a predictor of the outcomes of many diseases. • Left atrial strain has been confirmed as a marker of atrial functional status and demonstrated to be a sensitive tool in the subclinical phase of a disease. • A comprehensive evaluation of the three phases of atrial function by CMR-FT demonstrates an impairment before the onset of atrial enlargement, thus helping clinicians in their decision-making and improving patient outcomes.

Assessing left atrial function in patients with atrial fibrillation and valvular heart disease using cardiovascular magnetic resonance imaging

Background

Atrial fibrillation (AF) is common arrhythmia in valvular heart disease (VHD) and is associated with adverse outcomes.

Hypothesis

To evaluate the left atrial (LA) function in patients with AF‐VHD by cardiovascular magnetic resonance imaging feature tracking (CMR‐FT) using LA strain (ε_s/ε_e/ε_a) and their corresponding strain rate (SRs/SRe/SRa).

Methods

This was a retrospective cross‐sectional inter‐reader and intra‐reader reproducibility conducted from July 1, 2020, to January 31, 2021. A total of 39 patients with AF‐VHD (rheumatic heart valvular disease [RHVD] [n = 22], degenerative heart valvular disease [DHVD] [n = 17]) underwent MRI scans performed with drug‐controlled heart rate before correcting the rhythm and valves through maze procedure. Fifteen participants with normal cardiac MRI were included as healthy control. ε_s/SRs, ε_e/SRe, and ε_a/SRa, corresponding to LA reservoir, conduit, and booster‐pump function, were assessed using Feature Tracking software (CVI42 v5.12.1).

Results

Compared with healthy controls, LA global strain parameters (ε_s/ε_e/ε_a/SRs/SRe/SRa) were significantly decreased (all p < 0.001), while LA size and volume were increased in AF‐VHD group (all p < 0.001). In the subgroup, RHVD group showed lower LA total ejection fraction (LATEF) and strain data than DHVD group (12.6% ± 3.3% vs. 19.4 ± 8.6, p = 0.001). Decreased LATEF was significantly related to altered LA strain and strain rate, especially in ε_s, ε_e, and SRs (Pearson/Spearman r/ρ = 0.856/0.837/0.562, respectively; all p < 0.001). Interstudy and intrastudy reproducibility were consistent for LA volumetry and strain parameters (intraclass correlation coefficient: 0.88–0.99).

Conclusions

CMR‐FT can be used to assess the LA strain parameters, and identify LA dysfunction and deformation noninvasively, which could be a helpful functional imaging biomarker in the clinical treatment of AF‐VHD.

State-of-the-art myocardial strain by CMR feature tracking: clinical applications and future perspectives

Based on conventional cine sequences of cardiac magnetic resonance (CMR), feature tracking (FT) is an emerging tissue tracking technique that evaluates myocardial motion and deformation quantitatively by strain, strain rate, torsion, and dyssynchrony. It has been widely accepted in modern literature that strain analysis can offer incremental information in addition to classic global and segmental functional analysis. Furthermore, CMR-FT facilitates measurement of all cardiac chambers, including the relatively thin-walled atria and the right ventricle, which has been a difficult measurement to obtain with the reference standard technique of myocardial tagging. CMR-FT objectively quantifies cardiovascular impairment and characterizes myocardial function in a novel way through direct assessment of myocardial fiber deformation. The purpose of this review is to discuss the current status of clinical applications of myocardial strain by CMR-FT in a variety of cardiovascular diseases. KEY POINTS: • CMR-FT is of great value for differential diagnosis and provides incremental value for evaluating the progression and severity of diseases. • CMR-FT guides the early diagnosis of various cardiovascular diseases and provides the possibility for the early detection of myocardial impairment and additional information regarding subclinical cardiac abnormalities. • Direct assessment of myocardial fiber deformation using CMR-FT has the potential to provide prognostic information incremental to common clinical and CMR risk factors.

Multiparametric Cardiovascular Magnetic Resonance Approach in Diagnosing, Monitoring, and Prognostication of Myocarditis

Myocarditis represents the entity of an inflamed myocardium and is a diagnostic challenge caused by its heterogeneous presentation. Contemporary noninvasive evaluation of patients with clinically suspected myocarditis using cardiac magnetic resonance (CMR) includes dimensions and function of the heart chambers, conventional T2-weighted imaging, late gadolinium enhancement, novel T1 and T2 mapping, and extracellular volume fraction calculation. CMR feature-tracking, texture analysis, and artificial intelligence emerge as potential modern techniques to further improve diagnosis and prognostication in this clinical setting. This review will describe the evidence surrounding different CMR methods and image postprocessing methods and highlight their values for clinical decision making, monitoring, and risk stratification across stages of this condition.

Diagnostic and Prognostic Value of Cardiac Magnetic Resonance Strain in Suspected Myocarditis With Preserved LV-EF: A Comparison Between Patients With Negative and Positive Late Gadolinium Enhancement Findings

BACKGROUND

Late gadolinium enhancement (LGE) is absent in many patients with suspected myocarditis and preserved left ventricular ejection fraction (LV-EF), which poses difficulties in diagnosis and risk stratification.

PURPOSE

To investigate the diagnostic and prognostic value of ventricular myocardial strain in patients with suspected myocarditis, preserved LV-EF, and negative Lake Louis Criteria (LLC) by comparing the findings in LGE negative and LGE positive patients.

STUDY TYPE

Retrospective.

POPULATION

A total of 108 patients with clinically suspected myocarditis who did not satisfy LLC were divided into LGE negative (N = 65) and LGE positive (N = 43) groups. A control group consisted of 50 healthy volunteers.

FIELD STRENGTH/SEQUENCE

Steady-state free precession cine and phase-sensitive inversion recovery segmented gradient echo LGE sequences at 3.0 T.

ASSESSMENT

Myocardial strain of the ventricles was evaluated by feature tracking, major adverse cardiovascular events (MACE) were assessed during follow-up since the date of magnetic resonance examination.

STATISTICAL TESTS

Independent-samples t test, Mann-Whitney U test, receiver operating characteristic curve analysis, and Cox proportional hazard regression were performed. A P-value <0.05 was considered statistically significant.

RESULTS

Cardiac function and myocardial deformability were impaired in all patients relative to controls. Left ventricular-global radial (LV-GRS), circumferential (LV-GCS), and longitudinal (LV-GLS) strain had diagnostic value, even in LGE negative patients (sensitivity = 0.446, 0.523, and 0.662; specificity = 0.92, 0.80, and 0.64; AUC = 0.685, 0.675, and 0.648, respectively). After a median follow-up of 530.5 (interquartile range: 168.5-969.25) days, MACE occurred in 18 (16.67%) patients. Right ventricular GLS showed prognostic value in all patients and in LGE negative patients, both in univariable analysis (hazard ratio [HR] 1.049, 95% confidence interval [CI] 1.001-1.099 and HR 1.068, 95% CI 1.011-1.127, respectively) and in multivariable Cox survival analysis. LV-GLS was associated with MACE in LGE positive patients in multivariable Cox survival analysis.

DATA CONCLUSION

Myocardial strain provides diagnostic and prognostic value in suspected myocarditis with preserved LV-EF, even in the absence of LGE.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: 2.

Early cardiac involvement in patients with acute COVID-19 infection identified by multiparametric cardiovascular magnetic resonance imaging

Aims

In order to determine acute cardiac involvement in patients with COVID-19, we quantitatively evaluated tissue characteristics and mechanics by non-invasive cardiac magnetic resonance (CMR) in a cohort of patients within the first 10 days of the onset of COVID symptoms.

Methods and results

Twenty-five patients with reverse transcription polymerase chain reaction confirmed COVID-19 and at least one marker of cardiac involvement [cardiac symptoms, abnormal electrocardiograph (ECG), or abnormal cardiac biomarkers] and 25 healthy age- and gender-matched control subjects were recruited to the study. Patients were divided into those with elevated (n = 8) or normal TnI (n = 17). There were significant differences in global longitudinal strain among patients who were positive and negative for hs-TnI, and controls [−12.3 (−13.3, −11.5)%, −13.1 (−14.2, −9.8)%, and −15.7 (−18.3, −12.7)%, P = 0.004]. Native myocardial T1 relaxation times in patients with positive and negative hs-TnI manifestation (1169.8 ± 12.9 and 1113.2 ± 31.2 ms) were significantly higher than the normal (1065 ± 57 ms) subjects, respectively (P < 0.001). The extracellular volume (ECV) of patients who were positive and negative for hs-TnI was higher than that of the normal controls [32 (31, 33)%, 29 (27, 30)%, and 26 (24, 27.5)%, P < 0.001]. In our study, quantitative T2 mapping in patients who were positive and negative for hs-TnI [51 (47.9, 52.8) and 48 (47, 49.4) ms] was significantly higher than the normal [42 (41, 45.2) ms] subjects (P < 0.001).

Conclusion

In patients with early-stage COVID-19, myocardial oedema, and functional abnormalities are a frequent finding, while irreversible regional injury such as necrosis may be infrequent.

Reference Values for Left Atrial Strain and Strain Rate Based on a Large Sample of Healthy Chinese Adults: An MR-Feature Tracking Study

BACKGROUND

While reference values of left atrial (LA) deformation parameters in Western populations have been established, reference data in healthy Asian populations are limited.

PURPOSE

To establish age- and sex-specific reference values for LA strain and strain rate (SR) based on a large sample of healthy Chinese adults using magnetic resonance-feature tracking (MR-FT).

STUDY TYPE

Retrospective.

POPULATION

Four hundred and eight healthy Chinese adults (220 males, aged 43.5 ± 11.5 years; 188 females, aged 45.3 ± 12.8 years).

FIELD STRENGTH/SEQUENCE

1.5 T/balanced steady-state free precession.

ASSESSMENT

Reservoir strain (ε_s ), conduit strain (ε_e ), booster strain (ε_a ), peak positive SR (SRs), peak early negative SR (SRe), and peak late negative SR (SRa) were obtained by MR-FT.

STATISTICAL TESTS

We used Shapiro-Wilk test, Student's t-test, Mann-Whitney U-test, linear regression, and coefficient of determination (r² ).

RESULTS

Women demonstrated significantly greater LA strain (ε_s [%]: 44.0 ± 9.9 vs. 38.3 ± 8.7; ε_e [%]: 26.7 ± 8.0 vs. 22.3 ± 6.8; ε_a [%]: 17.3 ± 4.4 vs. 16.0 ± 3.8) and SR (SRs [/second]: 1.8 ± 0.5 vs. 1.6 ± 0.4; SRe [/second]: -2.5 ± 0.9 vs. -2.1 ± 0.7; SRa [/second]: -1.9 ± 0.6 vs. -1.8 ± 0.5) than men. For both sexes, aging was significantly associated with decreased ε_s , SRs, ε_e , and SRe (r²  = 0.07, r²  = 0.05, r²  = 0.19, and r²  = 0.24 for men; r²  = 0.13, r²  = 0.11, r²  = 0.31, and r²  = 0.46 for women), and significantly increased ε_a (r²  = 0.03 and r²  = 0.05 for men and women). There was no significant correlation between age and SRa in both sexes (P = 0.057 and P = 0.377 for men and women, respectively).

DATA CONCLUSION

We provide age- and sex-specific reference values for LA strain and SR based on a large sample of healthy Chinese adults using MR-FT.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 5.

Left ventricular myocardial strain and tissue characterization by cardiac magnetic resonance imaging in immune checkpoint inhibitor associated cardiotoxicity

Background

Immune checkpoint inhibitors (ICIs) are highly effective in treating cancer; however, cardiotoxicity can occur, including myocarditis. Cardiac magnetic resonance (CMR) imaging is useful for evaluation of myocarditis, although it has not been well studied in ICI cardiotoxicity.

Methods

We identified patients referred for CMR evaluation of ICI cardiotoxicity from September 2015 through September 2019. We assessed structural and functional parameters, feature tracking (FT) left ventricular and atrial strain, T2- weighted ratios and quantitative late gadolinium enhancement (LGE). We also applied the Updated Lake Louise Criteria for diagnosis of myocarditis.

Results

Of the 20 patients referred, the median left ventricular ejection fraction (LVEF) was 52.5% ± 19.1 and 50% had a normal LVEF (≥53%). FT strain analysis revealed an average abnormal global longitudinal strain (GLS) of −9.8%± 4.2%. In patients with a normal LVEF, the average GLS remained depressed at −12.3%± 2.4%. In all patients, GLS demonstrated a significant negative correlation with LVEF (r_s = −0.64, p 0.002). Sixteen patients (80%) had presence of LGE (14 non-ischemic pattern and 2 ischemic). Percent LGE did not correlate with any CMR parameters and notably did not correlate with LVEF (r_s = −0.29, p = 0.22) or GLS (r_s = 0.10, p = 0.67), highlighting the value of tissue characterization beyond functional assessment. Nine patients (45%) met full Updated Lake Louise Criteria and 85% met at least one criterion, suggestive of myocarditis in the correct clinical context. Thirteen patients (65%) were treated for ICI-associated myocarditis and, of these, 54% (n = 7) had recovery of LVEF to normal. There was no correlation between LVEF (p = 0.47), GLS (0.89), or % LGE (0.15) and recovery of LVEF with treatment.

Conclusion

In patients with suspected ICI cardiotoxicity, CMR is an important diagnostic tool, even in the absence of overt left ventricular dysfunction, as abnormalities in left ventricular strain, T2 signal and LGE can identifying disease.

Non-invasive assessment of early and acute myocarditis in a rat model using cardiac magnetic resonance tissue tracking analysis of myocardial strain

Background

Myocardial strain analysis can provide diagnostic and prognostic information for myocarditis. The aim of the present study was to assess early and acute myocarditis in a rat model using cardiac magnetic resonance tissue tracking (CMR-TT) for myocardial strain analysis. We compared the strain's findings with the histological and immunohistochemical results.

Methods

Experimental autoimmune myocarditis (EAM) was induced by footpad injections of porcine cardiac myosin. The rats were examined by 7.0T preclinical CMR at day 14 (n=15) and day 21 (n=16) after EAM induction and the two control groups (each n=15) were also examined at day 14 and day 21, respectively. Using CMR-TT, we found a global peak systolic radial strain (Err_SAX) and a circumferential strain (Ecc_SAX) from the short-axis cine views and a radial strain (Err_LAX) and a longitudinal strain (Ell_LAX) from the long-axis cine views, which were calculated by dedicated TT software. Subsequently, histological and immunohistochemical evaluations were performed.

Results

Ell_LAX significantly decreased in early myocarditis compared with the control (-23.40%±1.48% vs. -22.02%±0.81%, P<0.05). Err_SAX, Ecc_SAX, Err_LAX, and Ell_LAX values significantly reduced in acute myocarditis compared with the controls (Err_SAX: 34.27%±9.80% vs. 49.76%±4.97%, Ecc_SAX: -18.98%±3.69% vs. -24.13±1.23, Err_LAX: 33.21%±10.24% vs. 49.59%±5.69%, and Ell_LAX: -17.75%±3.58% vs. -23.39%±1.48%; P<0.001, respectively). The receiver operating characteristic curve showed that myocardial strain analysis had a good diagnostic performance in early and acute myocarditis. The pathological evaluation revealed that inflammatory lesions began to appear in early myocarditis and peaked in acute myocarditis.

Conclusions

The CMR-TT strain analysis allowed accurate and reliable evaluation of early and acute myocarditis in a rat model, and has the potential to serve as a diagnostic indicator for the assessment of myocardial dysfunction in myocarditis.

Defining the Reference Range for Left Ventricular Strain in Healthy Patients by Cardiac MRI Measurement Techniques: Systematic Review and Meta-Analysis

BACKGROUND. Echocardiography is the primary noninvasive technique for left ventricular (LV) strain measurement. MRI has potential advantages, although reference ranges and thresholds to differentiate normal from abnormal left ventricular global longitudinal strain (LVGLS), left ventricular global circumferential strain (LVGCS), and left ventricular global radial strain (LVGRS) are not yet established. OBJECTIVE. The purpose of our study was to determine the mean and lower limit of normal (LLN) of MRI-derived LV strain measurements in healthy patients and explore factors potentially influencing these measurements. EVIDENCE ACQUISITION. PubMed, Embase, and Cochrane Library databases were searched for studies published through January 1, 2020, that reported MRI-derived LV strain measurements in at least 30 healthy individuals. Mean and LLN measurements of LV strain were pooled using random-effects models overall and for studies stratified by measurement method (feature tracking [FT] or tagging). Additional subgroup and meta-regression analyses were performed. EVIDENCE SYNTHESIS. Twenty-three studies with a total of 1782 healthy subjects were included. Pooled means and LLNs for all studies were -18.6% (95% CI, -19.5% to -17.6%) and -13.3% (-13.9% to 12.7%) for LVGLS, -21.0% (-22.4% to -19.6%) and -15.6% (-17.0% to -14.3%) for LVGCS, and 38.7% (30.5-46.9%) and 20.6% (15.1-26.1%) for LVGRS. Pooled means and LLNs for LVGLS by strain measurement method were -19.4% (95% CI, -20.6% to -18.1%) and -13.1% (-14.2% to -12.0%) for FT and -15.6% (-16.2% to -15.1%) and -13.1% (-14.1% to -12.2%) for tagging. A later year of study publication, increasing patient age, and increasing body mass index were associated with more negative mean LVGLS values. An increasing LV end-diastolic volume index was associated with less negative mean LVGLS values. No factor was associated with LLN of LVGLS. CONCLUSION. We determined the pooled means and LLNs, with associated 95% CIs, for LV strain by cardiac MRI to define thresholds for normal, abnormal, and borderline strain in healthy patients. The method of strain measurement by MRI affected the mean LVGLS. No factor affected the LLN of LVGLS. CLINICAL IMPACT. This meta-analysis lays a foundation for clinical adoption of MRI-derived LV strain measurements, with management implications in both healthy patients and patients with various disease states.

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.

Myocardial involvement and deformation abnormalities in idiopathic inflammatory myopathy assessed by CMR feature tracking

Background

Cardiac involvement has been described in idiopathic inflammatory myopathies (IIM), including non-specific ECG and echocardiographic findings. Aim of our study was to evaluate myocardial deformation parameters in IIM and to correlate them with late gadolinium enhancement (LGE) findings using cardiac magnetic resonance imaging (CMR).

Methods

Forty-seven consecutive patients with histologically proven IIM were included into our study. Twenty-five healthy volunteers were used as a control group. All patients and controls underwent CMR examination using a 1.5 T scanner including functional cine and LGE imaging. After a mean follow-up of 234.7 ± 79.5 days a second CMR examination was performed in IIM patients.

Results

In comparison to healthy volunteers, IIM patients had lower left ventricular mass and left ventricular global radial, circumferential and longitudinal strain. There was no significant difference in left ventricular ejection fraction.

Patients with LGE (N = 28) had lower left ventricular ejection fraction (p = 0.016), global right and left ventricular longitudinal strain (p = 0.014 and p = 0.005) and global left ventricular diastolic longitudinal strain rate (p = 0.001) compared to patients without LGE (N = 19).

In IIM patients, a significant decrease of left ventricular ejection fraction, left ventricular mass and all measured deformation parameters was observed between baseline and follow-up CMR.

Conclusion

Cardiac involvement in IIM is frequent. Impairment of systolic and diastolic deformation parameters and a worsening over time can be observed. CMR is a useful tool for cardiac diagnostic work-up of these patients.

Tissue-tracking in the assessment of late gadolinium enhancement in myocarditis and myocardial infarction

PURPOSE

To test the diagnostic performance of cardiovascular magnetic resonance (CMR) tissue-tracking (TT) to detect the presence of late gadolinium enhancement (LGE) in patients with a diagnosis of myocardial infarction (MI) or myocarditis (MYO), preserved left ventricular ejection fraction (LVEF) and no visual regional wall motion abnormalities (RWMA).

METHODS

We selected consecutive CMR studies of 50 MI, 50 MYO and 96 controls. Receiving operating characteristic (ROC) curve and net reclassification index (NRI) analyses were used to assess the predictive ability and the incremental diagnostic yield of 2D and 3D TT-derived strain parameters for the detection of LGE and to measure the best cut-off values of strain parameters.

RESULTS

Overall, cases showed significantly reduced 2D global longitudinal strain (2D-GLS) values compared with controls (-20.1 ± 3.1% vs -21.6 ± 2.7%; p = 0.0008). 2D-GLS was also significantly reduced in MYO patients compared with healthy controls (-19.7 ± 2.9% vs -21.9 ± 2.4%; p = 0.0001). 3D global radial strain (3D-GRS) was significantly reduced in MI patients compared with controls with risk factors (34.3 ± 11.8% vs 40.3 ± 12.5%, p = 0.024) Overall, 2D-GLS yielded good diagnostic accuracy for the detection of LGE in the MYO subgroup (AUROC 0.79; NRI (95% CI) = 0.6 (0.3, 1.02) p = 0.0004), with incremental predictive value beyond risk factors and LV function parameters (p for AUROC difference = 0.048). In the MI subgroup, 2D-GRS (AUROC 0.81; NRI (95% CI) = 0.56 (0.17, 0.95) p = 0.004), 3D-GRS (AUROC 0.82; NRI (95% CI) = 0.57 (0.17, 0.97) p = 0.006) and 3D global circumferential strain (3D-GCS) (AUROC 0.81; NRI (95% CI) = 0.62 (0.22, 1.01) p = 0.002) emerged as potential markers of disease. The best cut-off for 2D-GLS was -21.1%, for 2D- and 3D-GRS were 39.1% and 37.7%, respectively, and for 3D-GCS was -16.4%.

CONCLUSIONS

At CMR-tissue tracking analysis, 2D-GLS was a significant predictor of LGE in patients with myocarditis but preserved LVEF and no visual RWMA. Both 2D- and 3D-GRS and 2D-GCS yielded good diagnostic accuracy for LGE detection in patients with previous MI but preserved LVEF and no visual RWMA.

Feature Tracking Myocardial Strain Incrementally Improves Prognostication in Myocarditis Beyond Traditional CMR Imaging Features

OBJECTIVES

This study investigated the association of cardiovascular cardiac magnetic resonance (CMR) feature tracking (FT) with outcome in a patient cohort with myocarditis and evaluated the possible incremental prognostic benefit beyond clinical features and traditional CMR features.

BACKGROUND

CMR is used to diagnose and risk stratify patients with myocarditis. CMR-FT allows quantitative strain analysis of myocardial function; however, its prognostic benefit in myocarditis is unknown.

METHODS

Consecutive patients with clinically suspected myocarditis and presence of midmyocardial or epicardial late gadolinium enhancement (LGE) and/or myocardial edema in CMR were included. Clinical and CMR features were analyzed with regard to major adverse cardiovascular events (MACE) (i.e., hospitalization for heart failure, sustained ventricular tachycardia, and all-cause mortality).

RESULTS

Of 740 patients with clinically suspected myocarditis, 455 (61%) met our final diagnostic criteria based on CMR tissue characterization. At a median follow-up of 3.9 years, MACE occurred in 74 (16%) patients. In the univariable analysis, CMR-FT global longitudinal peak strain (GLS) was significantly associated with MACE. In a multivariable model adjusting for clinical variables (age, sex, body mass index, and acuteness of symptoms) and traditional CMR features (left ventricular ejection fraction [LVEF] and LGE extent), GLS remained independently associated with outcome (GLS hazard ratio: 1.21; 95% confidence interval: 1.08 to 1.36; p = 0.001) and incrementally improved prognostication (chi-square increases from 42.6 to 79.8 to 88.5; p < 0.001).

CONCLUSIONS

Myocardial strain using CMR-FT provides independent and incremental prognostic value over clinical features, LVEF, and LGE in patients with myocarditis. CMR-FT may serve as a novel marker to improve risk stratification in myocarditis. (CMR Features in Patients With Suspected Myocarditis [CMRMyo]; NCT03470571).

Tissue Characterization by Mapping and Strain Cardiac MRI to Evaluate Myocardial Inflammation in Fulminant Myocarditis

BACKGROUND

The clinical value of novel mapping techniques and strain measures to assess myocardial inflammation in fulminant myocarditis (FM) has not been fully explored.

PURPOSE

To evaluate the ability of mapping and strain cardiac MRI to assess myocardial inflammation in patients with FM, and to which degree the strain metrics correlate with myocardial edema.

STUDY TYPE

Prospective.

POPULATION

Twenty-nine patients (37 ± 16 years, 48% male) with FM and 29 patients with nonfulminant acute myocarditis (NFAM) (29 ± 14 years, 69% male).

FIELD STRENGTH/SEQUENCE

3.0T; Cine imaging, black blood T₂ -weighted imaging, T₁ mapping, T₂ mapping, and late gadolinium enhancement.

ASSESSMENT

Native T₁ , extracellular volume (ECV), and T₂ were measured. Myocardial strain was evaluated by feature tracking.

STATISTICAL TESTS

Student's t- or Mann-Whitney U-test. Spearman correlation analysis.

RESULTS

The myocardial edema rate (2.6 ± 0.7 vs. 1.6 ± 0.2, P < 0.001) and late gadolinium enhancement (LGE) mass (16.5 [11.7, 41.7] vs. 6.9 [2.2, 15.8] g, P < 0.001) were significantly increased in FM patients when compared to the NFAM group. LGE in the FM group was predominantly located in the septal wall, and 38% of the patients showed a diffuse LGE pattern. Native T₁ , ECV, and T₂ values in the FM group were significantly more elevated than those with NFAM, while global peak radial, circumferential, and longitudinal strain values were significantly reduced (all P < 0.001). Circumferential strain showed the strongest correlations with ECV (r = 0.72, P < 0.001).

DATA CONCLUSION

Patients with FM showed significant differences in LGE patterns, increased edema, and decreased strain measurements compared to those with NFAM. Circumferential strain showed significant associations with quantitative cardiac MRI parameters of myocardial inflammation.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:930-938.

Regional right ventricular function in rats: a novel magnetic resonance imaging method for measurement of right ventricular strain

The function of the right ventricle (RV) is linked to clinical outcome in many cardiovascular diseases, but its role in experimental heart failure remains largely unexplored due to difficulties in measuring RV function in vivo. We aimed to advance RV imaging by establishing phase-contrast MRI (PC-MRI) as a robust method for measuring RV function in rodents. A total of 46 Wistar-Hannover rats with left ventricular (LV) myocardial infarction and 10 control rats (sham) were examined 6 wk after surgery. Using a 9.4-T preclinical MRI system, we utilized PC-MRI to measure strain/strain rate in the RV free wall under isoflurane anesthesia. Cine MRI was used to measure RV volumes. LV end-diastolic pressure (LVEDP) was measured and used to identify pulmonary congestion. The infarct rats were divided into two groups: those with signs of pulmonary congestion (PC), with LVEDP ≥ 15 mmHg ( n = 26) and those without signs of pulmonary congestion (NPC), with LVEDP < 15 mmHg ( n = 20). The NPC rats exhibited preserved RV strains/strain rates, whereas the PC rats exhibited reduced strains/strain rates (26–48% lower than sham). Of the strain parameters, longitudinal strain and strain rate exhibited the highest correlations to LVEDP and lung weight (rho = 0.65–0.72, P < 0.001). Basal longitudinal strain was most closely associated with signs of pulmonary congestion and indexes of RV remodeling. Longitudinal RV strain had higher area under the curve than ejection fraction for detecting subtle RV dysfunction (area under the curve = 0.85 vs. 0.67). In conclusion, we show for the first time that global and regional RV myocardial strain can be measured robustly in rodents. Reduced RV strain was closely associated with indexes of pulmonary congestion and molecular markers of RV remodeling.

NEW & NOTEWORTHY Global and regional right ventricular myocardial strain can be measured with high reproducibility and low interobserver variability in rodents using tissue phase mapping MRI. Reduced right ventricular strain was associated with indexes of pulmonary congestion and molecular markers of right ventricular remodeling. Regional strain in the basal myocardium was considerably higher than in the apical myocardium.

Non-contrast enhanced diagnosis of acute myocarditis based on the 17-segment heart model using 2D-feature tracking magnetic resonance imaging

PURPOSE

The aim of this study was to investigate the diagnostic value of myocardial deformation analysis based on the 17-segment heart model using non-contrast enhanced (CE) 2D tissue feature tracking (2D-FT) technique.

MATERIAL AND METHODS

Seventy patients with suspected myocarditis underwent a cardiovascular magnetic resonance (CMR) examination at 1.5 Tesla. A contrast-agent-free part of this CMR protocol was additionally performed in forty healthy volunteers (HV). Besides standard CMR data sets, 2D-FT derived segmental and global longitudinal, radial, and circumferential deformation parameters were analyzed. The 2D-FT results were compared to the combined findings from CMR imaging and endomyocardial biopsy (EMB).

RESULTS

Patients were assigned to three groups depending on their ejection fraction (EF) (<40%, 40-55%, ≥55%). Compared to HV, impaired EF (<55%) was significantly correlated to reduced segmental and global strain and strain rate values. The circumferential deformation analysis was more sensitive to myocardial changes than longitudinal and radial analysis. The segmental strain/strain rate had an accuracy of 84.3%/70.0% for the diagnosis of an acute myocarditis, stated by EMB and CMR in 42 of 70 patients. In patients with preserved EF, acute myocarditis could be ruled out using only segmental strain analysis with a negative predictive value of 87.5%.

CONCLUSION

In patients with suspected myocarditis, the deformation analysis based on the 17-segment heart model provides valuable information about functional myocardial inhomogeneity. This quantitative approach could be used in addition to the clinical standard CMR protocol and represents a promising tool in the framework of a prospective automatized multiparametric CMR imaging analysis.

Baseline LV ejection fraction by cardiac magnetic resonance and 2D echocardiography after ST-elevation myocardial infarction - influence of infarct location and prognostic impact

Objectives

The comparability of left ventricular ejection fraction (LVEF) measurements by cardiac magnetic resonance (CMR) and 2D echocardiography (2DE) early after ST-elevation myocardial infarction (STEMI) remains unclear.

Methods

In this study, LVEF measured by CMR and 2DE (Simpson’s method) were compared in 221 patients after STEMI treated by primary percutaneous coronary intervention. 2DE image quality was systematically assessed and studies reported by an accredited examiner. Intermodality agreement was assessed by the Bland–Altman method. Major adverse cardiac events (MACE) were defined as the composite of death, myocardial infarction or hospitalisation for heart failure. Patients were followed up for a median of 40.9 months (IQR 28.1–56).

Results

After non-anterior STEMI, LVEF measurements by 2DE (single and biplane) were consistently underestimated in comparison to CMR (CMR 55.7 ± 9.5% vs. 2DE-4CV 49 ± 8.2% (p = 0.06), 2DE-2CV 52 ± 8% (p < 0.001), 2DE-biplane 53.5 ± 7.1% (p = 0.01)). After anterior STEMI, there was no significant difference in LVEF measurements by 2DE and CMR with acceptable limits of agreement (CMR 49 ± 11% vs. 2DE-4CV 49 ± 8.2% (p = 0.8), 2DE-2CV 49 ± 9.2% (p = 0.9), 2DE-biplane 49.6 ± 8% (p = 0.5)). In total, 15% of patients experienced a MACE during follow-up. In multivariate Cox regression analysis, reduced LVEF (< 52%) as assessed by either 2DE or CMR was predictive of MACE (2DE HR = 2.57 (95% CI 1.1–6.2), p = 0.036; CMR HR = 2.51 (95% CI 1.1–5.7), p = 0.028).

Conclusions

At baseline after non-anterior STEMI, 2D echocardiography significantly underestimated LVEF in comparison to CMR, whereas after anterior infarction, measurements were within acceptable limits of agreement. Both imaging modalities offered similar prognostic values when a reduced LVEF < 52% was applied.

Key Points

• After non-anterior STEMI, 2D-echocardiography significantly underestimated LVEF compared with cardiac MRI

• An ejection fraction of < 52% in the acute post-infarct period by both 2D echocardiography and CMR offered similar prognostic values

Two-dimensional and three-dimensional cardiac magnetic resonance feature-tracking myocardial strain analysis in acute myocarditis patients with preserved ejection fraction

To explore the potential role of two- (2D) and three-dimensional (3D) cardiac magnetic resonance (CMR) feature tracking (FT) myocardial strain analysis in identifying sub-clinical myocardial systolic and diastolic dysfunction in acute myocarditis patients with preserved ejection fraction (EF). Prospective two centre study-control study. Thirty patients (9 female, 37.2 ± 11.8 years.) with a CMR diagnosis of acute myocarditis according to the Lake Louise Criteria and preserved EF (≥ 55%) were included in the analysis. CMR data from 24 healthy volunteers (11 female, 36.2 ± 12.5 years.) served as control. 2D and 3D LV tissue tracking analysis were performed in a random fashion by two double-blinded operators. Variables were checked for normality and analysed with parametric test. The baseline characteristics of myocarditis patients with preserved EF and the healthy volunteers were perfectly comparable, except for the LV mass index and T1 and T2 mapping values (p < 0.001). The results of the interobserver variability in the 2D and 3D LV CMR FT myocardial strain analysis were p > 0.42, ICC > 0.80 and η² > 0.98. There was no statistical difference in 2D and 3D global radial, circumferential and longitudinal strain peak (%) and both systolic and diastolic strain rate (1/s) between acute myocarditis with preserved EF and healthy volunteers (all p = ns). There were no difference in 2D and 3D global radial, circumferential and longitudinal strain peak and both systolic and diastolic strain rate of the LV between acute myocarditis patients with preserved ejection fraction and healthy volunteers.