Strain imaging using cardiac magnetic resonance

Assessment of subclinical left ventricle myocardial dysfunction using global myocardial work in type 2 diabetes mellitus patients with preserved left ventricle ejection fraction

BACKGROUND

The purpose of this study was to assess subclinical left ventricle (LV) myocardial dysfunction using global myocardial work (MW) in type 2 diabetes mellitus (T2DM) patients with preserved left ventricle ejection fraction (LVEF).

METHODS

Sixty T2DM patients and 60 normal controls were enrolled in the study. Apical 4-, 3- and 2-chamber views were acquired by two-dimensional echocardiography. Peak systolic myocardial global longitudinal strain (GLS), global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW), and myocardial work efficiency (GWE) were determined by speckle-tracking echocardiography (STE).

RESULTS

The GLS values in the T2DM patients were significantly lower than those in normal controls (p < 0.001). The GWW in T2DM patients was significantly greater than that in normal controls, while GWI, GCW and GWE was significantly lower (p < 0.001). Receiver operating characteristic (ROC) analysis showed there were no significant different difference between GWW, GWE and GLS in the area under the curves (AUCs). In T2DM patients, fasting plasma glucose was positively correlated with GWW but negatively correlated with GWE, and GLS was negatively correlated with GWI and GCW.

CONCLUSION

From the research, we found that global MW as new technique could detect the subclinical LV myocardial dysfunction and confirm that the impaired LV function in T2DM patients with preserved LV systolic function.

Quantifying Myocardial Strain of the Left Ventricle in Normal People Using Feature-Tracking Based on Computed Tomography Imaging

Objective: The objective was to evaluate the normal value of left ventricular myocardial strain using the computed tomography feature-tracking technique and to explore the correlation between myocardial strains and cardiac function parameters. Methods: Participants suspected of coronary heart disease were selected from 17 August 2020 to 5 November 2020 to undergo coronary computed tomography angiography using a third-generation dual-source CT scanner. Data were imported into a commercial software (Medis) after multiphase reconstruction. The cardiac function parameters, radial (Err), circumferential (Ecc), and longitudinal strain (Ell) of the left ventricle were recorded. Results: A total of 87 normal subjects were enrolled, including 41 males and 46 females. For healthy subjects, the global radial strain (GRS), circumferential strain (GCS), and longitudinal strain (GLS) of the left ventricle were 74.5 ± 15.2%, −22.7 ± 3.0%, and −26.6 ± 3.2%, respectively. The Err and Ecc absolute values (|Ecc|) were the largest at the apex, and the |Ell| gradually increased from the base to the apex. The Err and |Ecc| were the largest in the lateral and inferior wall, respectively. |Ell| showed a clockwise decrease from the lateral wall in the short axis. Meanwhile, the GRS and |GLS| in females were higher than that in males. Multiple linear regression analysis showed that both SV and LVEF were the independent determinants of GRS, GCS, and GLS. BMI and CO were the independent determined factors of GCS. Conclusions: At a reasonable radiation dose, CT feature-tracking is a feasible and reproducible method to analyze left ventricular myocardial strain. Left ventricular myocardial strain in normal subjects varies in gender, segments, levels, and regions.

Multimodality imaging approach to left ventricular dysfunction in diabetes: an expert consensus document from the European Association of Cardiovascular Imaging

Heart failure (HF) is among the most important and frequent complications of diabetes mellitus (DM). The detection of subclinical dysfunction is a marker of HF risk and presents a potential target for reducing incident HF in DM. Left ventricular (LV) dysfunction secondary to DM is heterogeneous, with phenotypes including predominantly systolic, predominantly diastolic, and mixed dysfunction. Indeed, the pathogenesis of HF in this setting is heterogeneous. Effective management of this problem will require detailed phenotyping of the contributions of fibrosis, microcirculatory disturbance, abnormal metabolism, and sympathetic innervation, among other mechanisms. For this reason, an imaging strategy for the detection of HF risk needs to not only detect subclinical LV dysfunction (LVD) but also characterize its pathogenesis. At present, it is possible to identify individuals with DM at increased risk HF, and there is evidence that cardioprotection may be of benefit. However, there is insufficient justification for HF screening, because we need stronger evidence of the links between the detection of LVD, treatment, and improved outcome. This review discusses the options for screening for LVD, the potential means of identifying the underlying mechanisms, and the pathways to treatment.

A Clinical Approach to Multimodality Imaging in Pulmonary Hypertension

Pulmonary hypertension (PH) is a clinical condition characterized by progressive elevations in mean pulmonary artery pressures and right ventricular dysfunction, associated with significant morbidity and mortality. For resting PH to develop, ~50-70% of the pulmonary vasculature must be affected, suggesting that even mild hemodynamic abnormalities are representative of advanced pulmonary vascular disease. The definitive diagnosis of PH is based upon hemodynamics measured by right heart catheterization; however this is an invasive and resource intense study. Early identification of pulmonary vascular disease offers the opportunity to improve outcomes by instituting therapies that slow, reverse, or potentially prevent this devastating disease. Multimodality imaging, including non-invasive modalities such as echocardiography, computed tomography, ventilation perfusion scans, and cardiac magnetic resonance imaging, has emerged as an integral tool for screening, classifying, prognosticating, and monitoring response to therapy in PH. Additionally, novel imaging modalities such as echocardiographic strain imaging, 3D echocardiography, dual energy CT, FDG-PET, and 4D flow MRI are actively being investigated to assess the severity of right ventricular dysfunction in PH. In this review, we will describe the utility and clinical application of multimodality imaging techniques across PH subtypes as it pertains to screening and monitoring of PH.

Protective effect of a chronic hypobaric hypoxic environment at high altitude on cardiotoxicity induced by doxorubicin in rats: a 7 T magnetic resonance study

Background

Doxorubicin (DOX)-induced cardiotoxicity (DIC), a major clinical problem, has no effective preventive therapies. We hypothesized that left ventricular (LV) systolic function would be improved in a chronic hypobaric hypoxia environment at high altitude. The purpose of this study was to investigate whether cardiovascular magnetic resonance could reveal the cardioprotective effect of chronic hypobaric hypoxia on DIC.

Methods

In total, 60 rats were randomly assigned to 1 of 6 groups (n=10 per group): the P group (plain), PD group (plain + DOX), HH group (high altitude), HHD4 group (high altitude + DOX for 4 weeks), HHD8 group (high altitude + DOX for 8 weeks), and HHD12 group (high altitude + DOX for 12 weeks). The rats were transported to either Yushu (altitude: 4,250 m) or Chengdu (altitude: 500 m) where they underwent intraperitoneal injection of DOX (5 mg/kg/week for 3 weeks) or saline. Preclinical 7 T cardiovascular magnetic resonance was performed at weeks 4, 8, and 12. Tissue tracking was used to measure LV cardiac function and to analyze global and segmental strains. Subsequently, histological and oxidative stress tests were performed to evaluate the protective effect of a high-altitude environment on DIC.

Results

The left ventricular ejection fraction (LVEF) and global and regional strains in the middle, apical, anterior, septal, inferior, and lateral segments (all P<0.05) were improved in the HHD4 group compared with the PD group. The global strain was significantly greater in absolute value in the HHD8 and HHD12 groups than in the HHD4 group (all P<0.05). Additionally, histological and enzyme-linked immunosorbent assay evaluations supported the in vivo results.

Conclusions

A chronic hypobaric and hypoxic environment at high altitude partially prevented cardiac dysfunction and increased global and regional strain in DIC rat models, thereby minimizing myocardial injury and fibrosis. In addition, by increasing the total duration of chronic hypobaric hypoxia, the global strain was further increased, which was likely due to reduced oxidative stress.

Evaluation of comprehensive myocardial contractility in children with Kawasaki disease by cardiac magnetic resonance in a large single center

BACKGROUND

Children with Kawasaki disease (KD) and coronary artery lesions (CALs) can develop myocardial ischemia, fibrosis, and abnormal contractility. We aimed to assess the association between myocardial mechanical deformation with myocardial fibrosis, ischemia, and CALs.

METHODS

In total, 76 KD and 20 healthy volunteers received cardiac magnetic resonance (CMR). Peak systolic left ventricular (LV) longitudinal, radial, and circumferential strain and strain rate [LV strain longitudinal (LVSL), LV strain radial (LVSR), LV strain circumferential (LVSC), LV strain rate longitudinal (LVSRL), LV strain rate radial (LVSRR), and LV strain rate circumferential (LVSRC)], along with late gadolinium enhancement (LGE), perfusion deficit, and CALs in related segments were analyzed. The KD group was subdivided by CALs, perfusion, and LGE results, and strain results were compared with controls and in subgroups.

RESULTS

Cardiac fibrosis and ischemia were not confined to the territory of CALs. In a global analysis, strain and strain rates were lower in the KD group, especially in the subgroup with LGE and perfusion deficit. In segmental analysis, LVSR, LVSC, LVSL, and LVSRR decreased in the giant aneurysm group, and a lower LVSR (20.369%±10.603% vs. 26.071%±12.349%) and LVSC (-13.37%±5.365% vs. -15.847%±5.778%) were observed in thrombosed segments. The strain and strain rate were all lower in segments with LGE and perfusion deficit, and no obvious difference was found between groups with and without stenosis. LVSR had a better ability to identify giant aneurysm, thrombosis, stenosis, perfusion deficit, and LGE.

CONCLUSIONS

We detected lower strain values in KD patients, which was more pronounced in segments with aneurysm, thrombi, LGE, and perfusion deficit. LVSR is useful to discern patients with higher risk.

Longitudinal CMR assessment of cardiac global longitudinal strain and hemodynamic forces in a mouse model of heart failure

To longitudinally assess left ventricle (LV) global longitudinal strain (GLS) and hemodynamic forces during the early stages of cardiac dysfunction in a mouse model of heart failure with preserved ejection fraction (HFpEF). Cardiac MRI measurements were performed in control mice (n = 6), and db/db mice (n = 7), whereby animals were scanned four times between the age of 11-15 weeks. After the first scan, the db/db animals received a doxycycline intervention to accelerate progression of HFpEF. Systolic function was evaluated based on a series of prospectively ECG-triggered short-axis CINE images acquired from base to apex. Cardiac GLS and hemodynamic forces values were evaluated based on high frame rate retrospectively gated 2-, 3-, and 4-chamber long-axis CINE images. Ejection fraction (EF) was not different between control and db/db animals, despite that cardiac output, as well as end systolic and end diastolic volume were significantly higher in control animals. Whereas GLS parameters were not significantly different between groups, hemodynamic force root mean square (RMS) values, as well as average hemodynamic forces and the ratio between hemodynamic forces in the inferolateral-anteroseptal and apical-basal direction were lower in db/db mice compared to controls. More importantly, hemodynamic forces parameters showed a significant interaction effect between time and group. Our results indicated that hemodynamic forces parameters were the only functional outcome measure that showed distinct temporal differences between groups. As such, changes in hemodynamic forces reflect early alterations in cardiac function which can be of added value in (pre)clinical research on HFpEF.

Advanced imaging tools for evaluating cardiac morphological and functional impairment in hypertensive disease

Arterial hypertension represents a systemic burden, and it is responsible of various morphological, functional and tissue modifications affecting the heart and the cardiovascular system. Advanced imaging techniques, such as speckle tracking and three-dimensional echocardiography, cardiac magnetic resonance, computed tomography and PET-computed tomography, are able to identify cardiovascular injury at different stages of arterial hypertension, from subclinical alterations and overt organ damage to possible complications related to pressure overload, thus giving a precious contribution for guiding timely and appropriate management and therapy, in order to improve diagnostic accuracy and prevent disease progression. The present review focuses on the peculiarity of different advanced imaging tools to provide information about different and multiple morphological and functional aspects involved in hypertensive cardiovascular injury. This evaluation emphasizes the usefulness of the emerging multiimaging approach for a comprehensive overview of arterial hypertension induced cardiovascular damage.

Left-Ventricular Reference Myocardial Strain Assessed by Cardiovascular Magnetic Resonance Feature Tracking and fSENC-Impact of Temporal Resolution and Cardiac Muscle Mass

Aims: Cardiac strain parameters are increasingly measured to overcome shortcomings of ejection fraction. For broad clinical use, this study provides reference values for the two strain assessment methods feature tracking (FT) and fast strain-encoded (fSENC) cardiovascular magnetic resonance (CMR) imaging, including the child/adolescent group and systematically evaluates the influence of temporal resolution and muscle mass on strain.

Methods and Results: Global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain values in 181 participants (54% women, 11–70 years) without cardiac illness were assessed with FT (CVI42® software). GLS and GCS were also analyzed using fSENC (MyoStrain® software) in a subgroup of 84 participants (60% women). Fourteen patients suffering hypertrophic cardiomyopathy (HCM) were examined with both techniques. CMR examinations were done on a 3.0T MR-system.

FT-GLS, FT-GCS, and FT-GRS were −16.9 ± 1.8%, −19.2 ± 2.1% and 34.2 ± 6.1%. fSENC-GLS was higher at −20.3 ± 1.8% (p < 0.001). fSENC-GCS was comparable at−19.7 ± 1.8% (p = 0.06). All values were lower in men (p < 0.001). Cardiac muscle mass correlated (p < 0.001) with FT-GLS (r = 0.433), FT-GCS (r = 0.483) as well as FT-GRS (r = −0.464) and acts as partial mediator for sex differences. FT-GCS, FT-GRS and fSENC-GLS correlated weakly with age. FT strain values were significantly lower at lower cine temporal resolutions, represented by heart rates (r = −0.301, −0.379, 0.385) and 28 or 45 cardiac phases per cardiac cycle (0.3–1.9% differences). All values were lower in HCM patients than in matched controls (p < 0.01). Cut-off values were −15.0% (FT-GLS), −19.3% (FT-GCS), 32.7% (FT-GRS), −17.2% (fSENC-GLS), and −17.7% (fSENC-GCS).

Conclusion: The analysis of reference values highlights the influence of gender, temporal resolution, cardiac muscle mass and age on myocardial strain values.

Non-invasive Imaging in Coronary Syndromes - Recommendations of the European Association of Cardiovascular Imaging and the American Society of Echocardiography, in Collaboration with the American Society of Nuclear Cardiology, Society of Cardiovascular Computed Tomography and Society for Cardiovascular Magnetic Resonance

Coronary artery disease (CAD) is one of the major causes of mortality and morbidity worldwide, with a high socioeconomic impact.(1) Non-invasive imaging modalities play a fundamental role in the evaluation and management of patients with known or suspected CAD. Imaging end-points have served as surrogate markers in many observational studies and randomized clinical trials that evaluated the benefits of specific therapies for CAD.(2) A number of guidelines and recommendations have been published about coronary syndromes by cardiology societies and associations, but have not focused on the excellent opportunities with cardiac imaging. The recent European Society of Cardiology (ESC) 2019 guideline on chronic coronary syndromes (CCS) and 2020 guideline on acute coronary syndromes in patients presenting with non-ST-segment elevation (NSTE-ACS) highlight the importance of non-invasive imaging in the diagnosis, treatment, and risk assessment of the disease.(3)(4) The purpose of the current recommendations is to present the significant role of non-invasive imaging in coronary syndromes in more detail. These recommendations have been developed by the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE), in collaboration with the American Society of Nuclear Cardiology, the Society of Cardiovascular Computed Tomography, and the Society for Cardiovascular Magnetic Resonance, all of which have approved the final document.

Non-Invasive Assessment of Left Ventricle Ejection Fraction: Where Do We Stand?

The left ventricular (LV) ejection fraction (EF) is the preferred parameter applied for the non-invasive evaluation of LV systolic function in clinical practice. It has a well-recognized and extensive role in the clinical management of numerous cardiac conditions. Many imaging modalities are currently available for the non-invasive assessment of LVEF. The aim of this review is to describe their relative advantages and disadvantages, proposing a hierarchical application of the different imaging tests available for LVEF evaluation based on the level of accuracy/reproducibility clinically required.

Numerical evaluation of cardiac mechanical markers as estimators of the electrical activation time

Recent advances in the development of noninvasive cardiac imaging technologies have made it possible to measure longitudinal and circumferential strains at a high spatial resolution also at intramural level. Local mechanical activation times derived from these strains can be used as noninvasive estimates of electrical activation, in order to determine, eg, the origin of premature ectopic beats during focal arrhythmias or the pathway of reentrant circuits. The aim of this work is to assess the reliability of mechanical activation time markers derived from longitudinal and circumferential strains, denoted by AT_ell and AT_ecc , respectively, by means of three-dimensional cardiac electromechanical simulations. These markers are compared against the electrical activation time (AT_v ), computed from the action potential waveform, and the reference mechanical activation markers derived from the active tension and fiber strain waveforms, denoted by AT_ta and AT_eff , respectively. Our numerical simulations are based on a strongly coupled electromechanical model, including bidomain representation of the cardiac tissue, mechanoelectric (ie, stretch-activated channels) and geometric feedbacks, transversely isotropic strain energy function for the description of passive mechanics and detailed membrane and excitation-contraction coupling models. The results have shown that, during endocardial and epicardial ectopic stimulations, all the mechanical markers considered are highly correlated with AT_v , exhibiting correlation coefficients larger than 0.8. However, during multiple endocardial stimulations, mimicking the ventricular sinus rhythm, the mechanical markers are less correlated with the electrical activation time, because of the more complex resulting excitation sequence. Moreover, the inspection of the endocardial and epicardial isochrones has shown that the AT_ell and AT_ecc mechanical activation sequences reproduce only some qualitative features of the electrical activation sequence, such as the areas of early and late activation, but in some cases, they might yield wrong excitation sources and significantly different isochrones patterns.

Atrial Strain by Feature-Tracking Cardiac Magnetic Resonance Imaging in Takotsubo Cardiomyopathy. Features, Feasibility, and Reproducibility

OBJECTIVES

The purpose of this study was to investigate whether there may be a bi-atrial dysfunction in Takotsubo syndrome (TS) during the transient course of the disease, using cardiac magnetic resonance imaging feature tracking (CMR-FT) in analyzing bi-atrial strain.

METHOD

Eighteen TS patients and 13 healthy controls were studied. Reservoir, conduit, and booster bi-atrial functions were analyzed by CMR-FT. The correlation between LA and RA strain parameters was assessed. Intra- and inter-observer reproducibility was evaluated for all strain and strain rate (SR) parameters using intraclass correlation coefficients (ICCs) and Bland-Altman analysis.

RESULTS

Atrial strain were feasible in all patients and controls. Takotsubo patients showed an impaired LA Reservoir strain (∊_s), LA Reservoir strain rate (SRs), LA and RA Conduit strain(∊_e), LA and RA conduit strain rate (SRe) in comparison with controls (P < 0.001 for all of them), while no differences were found as to LA and RA booster deformation parameters (∊_a and SRa). Analysis of correlation showed that LA ∊_s, SRs, ∊_e, and SRe were positively correlated with corresponding RA strain measurements (P < 0.001, r = 0.61 and P = 0,03, r = 0,54, respectively). Reproducibility was good to excellent for all atrial strain and strain rate parameters (ICCs ranging from 0,50 to 0,96).

CONCLUSION

Atrial strain analysis using CMR-FT may be a useful tool to reveal new pathophysiological insights in Takotsubo cardiomyopathy. Additional studies, with a larger number of patients, are needed to confirm the possible role of these advanced CMR tools in characterizing TS patients.

Using synthetic data generation to train a cardiac motion tag tracking neural network

A CNN based method for cardiac MRI tag tracking was developed and validated. A synthetic data simulator was created to generate large amounts of training data using natural images, a Bloch equation simulation, a broad range of tissue properties, and programmed ground-truth motion. The method was validated using both an analytical deforming cardiac phantom and in vivo data with manually tracked reference motion paths. In the analytical phantom, error was investigated relative to SNR, and accurate results were seen for SNR>10 (displacement error <0.3 mm). Excellent agreement was seen in vivo for tag locations (mean displacement difference = -0.02 pixels, 95% CI [-0.73, 0.69]) and calculated cardiac circumferential strain (mean difference = 0.006, 95% CI [-0.012, 0.024]). Automated tag tracking with a CNN trained on synthetic data is both accurate and precise.

Multimodality cardiac evaluation in children and young adults with multisystem inflammation associated with COVID-19

Aims

Following the peak of the UK COVID-19 epidemic, a new multisystem inflammatory condition with significant cardiovascular effects emerged in young people. We utilized multimodality imaging to provide a detailed sequential description of the cardiac involvement.

Methods and Results

Twenty consecutive patients (mean age 10.6 ± 3.8 years) presenting to our institution underwent serial echocardiographic evaluation on admission (median day 5 of illness), the day coinciding with worst cardiac function (median day 7), and the day of discharge (median day 15). We performed cardiac computed tomography (CT) to assess coronary anatomy (median day 15) and cardiac magnetic resonance imaging (CMR) to assess dysfunction (median day 20). On admission, almost all patients displayed abnormal strain and tissue Doppler indices. Three-dimensional (3D) echocardiographic ejection fraction (EF) was <55% in half of the patients. Valvular regurgitation (75%) and small pericardial effusions (10%) were detected. Serial echocardiography demonstrated that the mean 3D EF deteriorated (54.7 ± 8.3% vs. 46.4 ± 8.6%, P = 0.017) before improving at discharge (P = 0.008). Left main coronary artery (LMCA) dimensions were significantly larger at discharge than at admission (Z score –0.11 ± 0.87 vs. 0.78 ± 1.23, P = 0.007). CT showed uniform coronary artery dilatation commonly affecting the LMCA (9/12). CMR detected abnormal strain in all patients with global dysfunction (EF <55%) in 35%, myocardial oedema in 50%, and subendocardial infarct in 5% (1/20) patients.

Conclusions

Pancarditis with cardiac dysfunction is common and associated with myocardial oedema. Patients require close monitoring due to coronary artery dilatation and the risk of thrombotic myocardial infarction.

Causes of altered ventricular mechanics in hypertrophic cardiomyopathy: an in-silico study

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is typically caused by mutations in sarcomeric genes leading to cardiomyocyte disarray, replacement fibrosis, impaired contractility, and elevated filling pressures. These varying tissue properties are associated with certain strain patterns that may allow to establish a diagnosis by means of non-invasive imaging without the necessity of harmful myocardial biopsies or contrast agent application. With a numerical study, we aim to answer: how the variability in each of these mechanisms contributes to altered mechanics of the left ventricle (LV) and if the deformation obtained in in-silico experiments is comparable to values reported from clinical measurements.

METHODS

We conducted an in-silico sensitivity study on physiological and pathological mechanisms potentially underlying the clinical HCM phenotype. The deformation of the four-chamber heart models was simulated using a finite-element mechanical solver with a sliding boundary condition to mimic the tissue surrounding the heart. Furthermore, a closed-loop circulatory model delivered the pressure values acting on the endocardium. Deformation measures and mechanical behavior of the heart models were evaluated globally and regionally.

RESULTS

Hypertrophy of the LV affected the course of strain, strain rate, and wall thickening-the root-mean-squared difference of the wall thickening between control (mean thickness 10 mm) and hypertrophic geometries (17 mm) was >10%. A reduction of active force development by 40% led to less overall deformation: maximal radial strain reduced from 26 to 21%. A fivefold increase in tissue stiffness caused a more homogeneous distribution of the strain values among 17 heart segments. Fiber disarray led to minor changes in the circumferential and radial strain. A combination of pathological mechanisms led to reduced and slower deformation of the LV and halved the longitudinal shortening of the LA.

CONCLUSIONS

This study uses a computer model to determine the changes in LV deformation caused by pathological mechanisms that are presumed to underlay HCM. This knowledge can complement imaging-derived information to obtain a more accurate diagnosis of HCM.

Advanced cardiovascular multimodal imaging and aortic stenosis

Aortic valve stenosis has become the most common valvular heart disease on account of aging population and increasing life expectancy. Echocardiography is the primary diagnosis tool for this, but it still has many flaws. Therefore, advanced cardiovascular multimodal imaging techniques are continuously being developed in order to overcome these limitations. Cardiac magnetic resonance imaging (CMR) allows a comprehensive morphological and functional evaluation of the aortic valve and provides important data for the diagnosis and risk stratification in patients with aortic stenosis. CMR can functionally assess the aortic flow using two-dimensional and time-resolved three-dimensional velocity-encoded phase-contrast techniques. Furthermore, by late gadolinium enhancement and T1-mapping, CMR can reveal the presence of both irreversible replacement and diffuse interstitial myocardial fibrosis. Moreover, its role in guiding aortic valve replacement procedures is beginning to take shape. Recent studies have rendered the importance of active and passive biomechanics in risk stratification and prognosis prediction in patients with aortic stenosis, but more work is required is just in its infancy, but data are promising. In addition, cardiac computed tomography is particularly useful for the diagnosis of aortic valve stenosis, and in preprocedural evaluation of the aorta, while positron emission tomography can be also used to assess valvular inflammation and active calcification. The purpose of this review is to provide a comprehensive overview of current available data regarding advanced cardiovascular multimodal imaging in aortic stenosis.

Transthyretin cardiac amyloidosis: a review of the nuclear imaging findings with emphasis on the radiotracers mechanisms

Cardiac amyloidosis is a protein deposition disease characterized by the infiltration of the myocardium and coronary arteries resulting in a progressive thickening of both ventricles, interatrial septum and atrioventricular valves, eventually leading to organ failure. It is a disease hard to diagnose, due to the lack of diagnostic investigations. However, development of new and more accurate examinations is undergoing. Endomyocardial biopsy is the gold standard investigation for this disease, but it has its limitations (invasive and not widely available). Other investigations may be able to detect the presence of cardiac amyloidosis but cannot specify the type involved. To that end, nuclear medicine through bone scanning offers a simple, non-invasive solution to detect, differentiate and diagnose transthyretin cardiac amyloidosis (ATTR) from other types of cardiac amyloidosis. In order to demonstrate the importance of bone scanning we will present a few methods of image processing based on literature and a personalized method, followed by a few important examples of positive cases. The aim of this review was to present the current methods of ATTR detection with emphasis on nuclear medicine bone scanning and its important place in the decision algorithm of the cardiologist for a personalized approach to this pathology.

Multi-parametric assessment of left ventricular hypertrophy using late gadolinium enhancement, T1 mapping and strain-encoded cardiovascular magnetic resonance

AIM

To evaluate the ability of single heartbeat fast-strain encoded (SENC) cardiovascular magnetic resonance (CMR) derived myocardial strain to discriminate between different forms of left ventricular (LV) hypertrophy (LVH).

METHODS

314 patients (228 with hypertensive heart disease (HHD), 45 with hypertrophic cardiomyopathy (HCM), 41 with amyloidosis, 22 competitive athletes, and 33 healthy controls) were systematically analysed. LV ejection fraction (LVEF), LV mass index and interventricular septal (IVS) thickness, T1 mapping and atypical late gadolinium enhancement (LGE) were assessed. In addition, the percentage of LV myocardial segments with strain ≤ - 17% (%normal myocardium) was determined.

RESULTS

Patients with amyloidosis and HCM exhibited the highest IVS thickness (17.4 ± 3.3 mm and 17.4 ± 6 mm, respectively, p < 0.05 vs. all other groups), whereas patients with amyloidosis showed the highest LV mass index (95.1 ± 20.1 g/m2, p < 0.05 vs all others) and lower LVEF compared to controls (50.5 ± 9.8% vs 59.2 ± 5.5%, p < 0.05). Analysing subjects with mild to moderate hypertrophy (IVS 11-15 mm), %normal myocardium exhibited excellent and high precision, respectively for the differentiation between athletes vs. HCM (sensitivity and specificity = 100%, Area under the curve; AUC%normalmyocardium = 1.0, 95%CI = 0.85-1.0) and athletes vs. HHD (sensitivity = 83%, specificity = 75%, AUC%normalmyocardium = 0.85, 95%CI = 0.78-0.90). Combining %normal myocardial strain with atypical LGE provided high accuracy also for the differentiation of HHD vs. HCM (sensitivity = 82%, specificity = 100%, AUCcombination = 0.92, 95%CI = 0.88-0.95) and HCM vs. amyloidosis (sensitivity = 83%, specificity = 100%, AUCcombination = 0.83, 95%CI = 0.60-0.96).

CONCLUSION

Fast-SENC derived myocardial strain is a valuable tool for differentiating between athletes vs. HCM and athletes vs. HHD. Combining strain and LGE data is useful for differentiating between HHD vs. HCM and HCM vs. cardiac amyloidosis.

The challenges of an aging tetralogy of Fallot population

Introduction: Advancements in surgery and management have resulted in a growing population of aging adults with tetralogy of Fallot (TOF). As a result, there has been a parallel growth in late complications associated with the sequelae from the underlying cardiac anomalies as well as the surgical and other interventional treatments.Areas covered: Here, we review challenges related to an aging population of patients with TOF, particularly late complications, and highlight advances in management and key areas for future research. Pulmonary regurgitation, heart failure, arrhythmias, and aortic complications are some of these late complications. There is also a growing incidence of acquired cardiovascular disease, obesity, and diabetes associated with aging. Management of these late complications and acquired comorbidities continues to evolve as research provides insights into long-term outcomes from medical therapies and surgical interventions.Expert opinion: The management of an aging TOF population will continue to transform with advances in imaging technologies to identify subclinical disease and valve replacement technologies that will prevent and mitigate disease progression. In the coming years, we speculate that there will be more data to support the use of novel heart failure therapies in TOF and consensus guidelines on the management of refractory arrhythmias and aortic complications.

3D-Encoded DENSE MRI with Zonal Excitation for Quantifying Biventricular Myocardial Strain During a Breath-Hold

PURPOSE

Right ventricular (RV) function is increasingly recognized for its prognostic value in many disease states. As with the left ventricle (LV), strain-based measurements may have better prognostic value than typical chamber volumes or ejection fraction. Complete functional characterization of the RV requires high-resolution, 3D displacement tracking methods, which have been prohibitively challenging to implement. Zonal excitation during Displacement ENcoding with Stimulated Echoes (DENSE) magnetic resonance imaging (MRI) has helped reduce scan time for 2D LV strain quantification. We hypothesized that zonal excitation could alternatively be used to reproducibly acquire higher resolution, 3D-encoded DENSE images for quantification of bi-ventricular strain within a single breath-hold.

METHODS

We modified sequence parameters for a 3D zonal excitation DENSE sequence to achieve in-plane resolution < 2 mm and acquired two sets of images in eight healthy adult male volunteers with median (IQR) age 32.5 (32.0-33.8) years. We assessed the inter-test reproducibility of this technique, and compared computed strains and torsion with previously published data.

RESULTS

Data for one subject was excluded based on image artifacts. Reproducibility for LV (CoV: 6.1-9.0%) and RV normal strains (CoV: 6.3-8.2%) and LV torsion (CoV = 7.1%) were all very good. Reproducibility of RV torsion was lower (CoV = 16.7%), but still within acceptable limits. Computed global strains and torsion were within reasonable agreement with published data, but further studies in larger cohorts are needed to confirm.

CONCLUSION

Reproducible acquisition of 3D-encoded biventricular myocardial strain data in a breath-hold is feasible using DENSE with zonal excitation.

CMR-Based Risk Stratification of Sudden Cardiac Death and Use of Implantable Cardioverter-Defibrillator in Non-Ischemic Cardiomyopathy

Non-ischemic cardiomyopathy (NICM) is one of the most important entities for arrhythmias and sudden cardiac death (SCD). Previous studies suggest a lower benefit of implantable cardioverter–defibrillator (ICD) therapy in patients with NICM as compared to ischemic cardiomyopathy (ICM). Nevertheless, current guidelines do not differentiate between the two subgroups in recommending ICD implantation. Hence, risk stratification is required to determine the subgroup of patients with NICM who will likely benefit from ICD therapy. Various predictors have been proposed, among others genetic mutations, left-ventricular ejection fraction (LVEF), left-ventricular end-diastolic volume (LVEDD), and T-wave alternans (TWA). In addition to these parameters, cardiovascular magnetic resonance imaging (CMR) has the potential to further improve risk stratification. CMR allows the comprehensive analysis of cardiac function and myocardial tissue composition. A range of CMR parameters have been associated with SCD. Applicable examples include late gadolinium enhancement (LGE), T1 relaxation times, and myocardial strain. This review evaluates the epidemiological aspects of SCD in NICM, the role of CMR for risk stratification, and resulting indications for ICD implantation.

Abnormal P-wave terminal force in lead V1 is a marker for atrial electrical dysfunction but not structural remodelling

Aims

There is a lack of diagnostic and therapeutic options for patients with atrial cardiomyopathy and paroxysmal atrial fibrillation. Interestingly, an abnormal P‐wave terminal force in electrocardiogram lead V₁ (PTFV₁) has been associated with atrial cardiomyopathy, but this association is poorly understood. We investigated PTFV₁ as a marker for functional, electrical, and structural atrial remodelling.

Methods and results

Fifty‐six patients with acute myocardial infarction and 13 kidney donors as control cohort prospectively underwent cardiac magnetic resonance imaging to evaluate the association between PTFV₁ and functional remodelling (atrial strain). To further investigate underlying pathomechanisms, right atrial appendage biopsies were collected from 32 patients undergoing elective coronary artery bypass grafting. PTFV₁ was assessed as the product of negative P‐wave amplitude and duration in lead V₁ and defined as abnormal if ≥4000 ms*μV. Activity of cardiac Ca/calmodulin‐dependent protein kinase II (CaMKII) was determined by a specific HDAC4 pull‐down assay as a surrogate for electrical remodelling. Atrial fibrosis was quantified using Masson's trichrome staining as a measure for structural remodelling. Multivariate regression analyses were performed to account for potential confounders. A total of 16/56 (29%) of patients with acute myocardial infarction, 3/13 (23%) of kidney donors, and 15/32 (47%) of patients undergoing coronary artery bypass grafting showed an abnormal PTFV₁. In patients with acute myocardial infarction, left atrial (LA) strain was significantly reduced in the subgroup with an abnormal PTFV₁ (LA reservoir strain: 32.28 ± 12.86% vs. 22.75 ± 13.94%, P = 0.018; LA conduit strain: 18.87 ± 10.34% vs. 10.17 ± 8.26%, P = 0.004). Abnormal PTFV₁ showed a negative correlation with LA conduit strain independent from clinical covariates (coefficient B: −7.336, 95% confidence interval −13.577 to −1.095, P = 0.022). CaMKII activity was significantly increased from (normalized to CaMKII expression) 0.87 ± 0.17 to 1.46 ± 0.15 in patients with an abnormal PTFV₁ (P = 0.047). This increase in patients with an abnormal PTFV₁ was independent from clinical covariates (coefficient B: 0.542, 95% confidence interval 0.057 to 1.027, P = 0.031). Atrial fibrosis was significantly lower with 12.32 ± 1.63% in patients with an abnormal PTFV₁ (vs. 20.50 ± 2.09%, P = 0.006), suggesting PTFV₁ to be a marker for electrical but not structural remodelling.

Conclusions

Abnormal PTFV₁ is an independent predictor for impaired atrial function and for electrical but not for structural remodelling. PTFV₁ may be a promising tool to evaluate patients for atrial cardiomyopathy and for risk of atrial fibrillation.

Contemporary Role of Cardiac Magnetic Resonance in the Management of Patients with Suspected or Known Coronary Artery Disease

Cardiac magnetic resonance imaging (CMR) is a useful non-invasive radiation-free imaging modality for the management of patients with coronary artery disease (CAD). CMR cine imaging provides the “gold standard” assessment of ventricular function, late gadolinium enhancement (LGE) provides useful data for the diagnosis and extent of myocardial scar and viability, while stress imaging is an established technique for the detection of myocardial perfusion defects indicating ischemia. Beyond its role in the diagnosis of CAD, CMR allows accurate risk stratification of patients with established CAD. This review aims to summarize the data regarding the role of CMR in the contemporary management of patients with suspected or known coronary artery disease.

Multichamber Dysfunction in Children and Adolescents With Severe Obesity: A Cardiac Magnetic Resonance Imaging Myocardial Strain Study

BACKGROUND

In severe obesity, left ventricular (LV) and right ventricular (RV) remodeling and contractile dysfunction have been documented, but less is known regarding left atrial (LA) dysfunction and its association with LV/RV remodeling, especially in children.

PURPOSE

To assess the effects of severe childhood obesity on cardiac function by using multichamber strain analysis with MRI.

STUDY TYPE

Prospective.

SUBJECTS

Forty-five children aged 7-18 years (including 20 with severe obesity, defined as a body mass index values above the 99th percentile).

FIELD STRENGTH

5 T.

SEQUENCE

Steady-state-free-precession (SSFP) images in short-axis views and longitudinal two- and four-chamber views.

ASSESSMENT

Cardiac strain measurements were derived from standard SSFP cine images by using a dedicated MR imaging feature tracking software. Inter- and intra-rater reliability were evaluated.

STATISTICAL TESTS

Independent sample t test, Spearman's correlation coefficient, principal component analysis, Bland-Altman analysis, and intra-class correlation coefficients (ICC). A P value <0.05 was considered statistically significant.

RESULTS

As compared to children without obesity, those with obesity showed significantly reduced LA reservoir function (22.2% ± 6.4% vs. 33.8% ± 9.0%) and contractile function (5.4% ± 3.2% vs. 13.3% ± 8.0%) as well as significantly decreased absolute values for LA longitudinal strain in reservoir and contraction phases and LA radial motion fraction in reservoir and contraction phases. Children with severe obesity showed significantly reduced absolute RV radial motion fraction (-10.6% ± 2.9% vs. -18.2% ± 2.9%) and circumferential strain (-10.6% ± 2.9% vs. -16% ± 2.5%) as well as higher LV mass index (28.7% ± 5.1% vs. 21.7 ± 4.6 g/m² ) along with significantly reduced LV ejection fraction (56.4% ± 3.9% vs. 60% ± 4.1%), LV radial strain (56% ± 6% vs. 61.8% ± 11.3%), and longitudinal strain (-17.8% ± 1.8% vs. -20.3% ± 3.2%). Reliability was good to excellent, with ICC ranging from 79.1% to 97.7%.

DATA CONCLUSION

MR feature-tracking strain analysis revealed multichamber dysfunction in severely obese children with impaired LA reservoir and atrial contraction phases, which suggest an early loss in the compensatory ability of atrial contraction with severe obesity.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 3.

Cardiac Magnetic Resonance to Detect the Underlying Substrate in Patients with Frequent Idiopathic Ventricular Arrhythmias

BACKGROUND

A routine diagnostic work-up does not identify structural abnormalities in a substantial proportion of patients with idiopathic ventricular arrhythmias (VAs). We investigated the added value of cardiac magnetic resonance (CMR) imaging in this group of patients.

METHODS

A single-centre prospective study was undertaken of 72 patients (mean age 46 ± 16 years; 53% females) with frequent premature ventricular contractions (PVCs ≥ 500/24 h) and/or non-sustained ventricular tachycardia (NSVT), an otherwise normal electrocardiogram, normal echocardiography and no coronary artery disease.

RESULTS

CMR provided an additional diagnostic yield in 54.2% of patients. The most prevalent diagnosis was previous myocarditis (23.6%) followed by possible PVC-related cardiomyopathy (20.8%), non-ischaemic cardiomyopathy (8.3%) and ischaemic heart disease (1.4%). The predictors of abnormal CMR findings were male gender, age and PVCs/NSVT non-outflow tract-related or with multiple morphologies. Patients with VAs had an impaired peak left ventricular (LV) global radial strain (GRS) compared with the controls (28.88% (IQR: 25.87% to 33.97%) vs. 36.65% (IQR: 33.19% to 40.2%), p < 0.001) and a global circumferential strain (GCS) (-17.66% (IQR: -19.62% to -16.23%) vs. -20.66% (IQR: -21.72% to -19.6%), p < 0.001).

CONCLUSION

CMR reveals abnormalities in a significant proportion of patients with frequent idiopathic VAs. Male gender, age and non-outflow tract PVC origin can be clinical indicators for CMR referral.

Segmental strain analysis for the detection of chronic ischemic scars in non-contrast cardiac MRI cine images

Cardiac magnetic resonance imaging (MRI) with late gadolinium enhancement (LGE) is considered the gold standard for scar detection after myocardial infarction. In times of increasing skepticism about gadolinium depositions in brain tissue and contraindications of gadolinium administration in some patient groups, tissue strain-based techniques for detecting ischemic scars should be further developed as part of clinical protocols. Therefore, the objective of the present work was to investigate whether segmental strain is noticeably affected in chronic infarcts and thus can be potentially used for infarct detection based on routinely acquired non-contrast cine images in patients with known coronary artery disease (CAD). Forty-six patients with known CAD and chronic scars in LGE images (5 female, mean age 52 ± 19 years) and 24 gender- and age-matched controls with normal cardiac MRI (2 female, mean age 47 ± 13 years) were retrospectively enrolled. Global (global peak circumferential [GPCS], global peak longitudinal [GPLS], global peak radial strain [GPRS]) and segmental (segmental peak circumferential [SPCS], segmental peak longitudinal [SPLS], segmental peak radial strain [SPRS]) strain parameters were calculated from standard non-contrast balanced SSFP cine sequences using commercially available software (Segment CMR, Medviso, Sweden). Visual wall motion assessment of short axis cine images as well as segmental circumferential strain calculations (endo-/epicardially contoured short axis cine and resulting polar plot strain map) of every patient and control were presented in random order to two independent blinded readers, which should localize potentially infarcted segments in those datasets blinded to LGE images and patient information. Global strain values were impaired in patients compared to controls (GPCS p = 0.02; GPLS p = 0.04; GPRS p = 0.01). Patients with preserved ejection fraction showed also impeded GPCS compared to healthy individuals (p = 0.04). In patients, mean SPCS was significantly impaired in subendocardially (-  5.4% ± 2) and in transmurally infarcted segments (- 1.2% ± 3) compared to remote myocardium (- 12.9% ± 3, p = 0.02 and 0.03, respectively). ROC analysis revealed an optimal cut-off value for SPCS for discriminating infarcted from remote myocardium of - 7.2% with a sensitivity of 89.4% and specificity of 85.7%. Mean SPRS was impeded in transmurally infarcted segments (15.9% ± 6) compared to SPRS of remote myocardium (31.4% ± 5; p = 0.02). The optimal cut-off value for SPRS for discriminating scar tissue from remote myocardium was 16.6% with a sensitivity of 83.3% and specificity of 76.5%. 80.3% of all in LGE infarcted segments (118/147) were correctly localized in segmental circumferential strain calculations based on non-contrast cine images compared to 53.7% (79/147) of infarcted segments detected by visual wall motion assessment (p > 0.01). Global strain parameters are impaired in patients with chronic infarcts compared to controls. Mean SPCS and SPRS in scar tissue is impeded compared to remote myocardium in infarcts patients. Blinded to LGE images, two readers correctly localized 80% of infarcted segments in segmental circumferential strain calculations based on non-contrast cine images, in contrast to only 54% of infarcted segments detected due to wall motion abnormalities in visual wall motion assessment. Analysis of segmental circumferential strain shows a promising method for detection of chronic scars in routinely acquired, non-contrast cine images for patients who cannot receive or decline gadolinium.

Arbitrary Point Tracking with Machine Learning to Measure Cardiac Strains in Tagged MRI

Cardiac tagged MR images allow for deformation fields to be measured in the heart by tracking the motion of tag lines throughout the cardiac cycle. Machine learning (ML) algorithms enable accurate and robust tracking of tag lines. Herein, the use of a massive synthetic physics-driven training dataset with known ground truth was used to train an ML network to enable tracking any number of points at arbitrary positions rather than anchored to the tag lines themselves. The tag tracking and strain calculation methods were investigated in a computational deforming cardiac phantom with known (ground truth) strain values. This enabled both tag tracking and strain accuracy to be characterized for a range of image acquisition and tag tracking parameters. The methods were also tested on in vivo volunteer data. Median tracking error was <0.26mm in the computational phantom, and strain measurements were improved in vivo when using the arbitrary point tracking for a standard clinical protocol.

Defining the optimal temporal and spatial resolution for cardiovascular magnetic resonance imaging feature tracking

BACKGROUND

Myocardial deformation analyses using cardiovascular magnetic resonance (CMR) feature tracking (CMR-FT) have incremental value in the assessment of cardiac function beyond volumetric analyses. Since guidelines do not recommend specific imaging parameters, we aimed to define optimal spatial and temporal resolutions for CMR cine images to enable reliable post-processing.

METHODS

Intra- and inter-observer reproducibility was assessed in 12 healthy subjects and 9 heart failure (HF) patients. Cine images were acquired with different temporal (20, 30, 40 and 50 frames/cardiac cycle) and spatial resolutions (high in-plane 1.5 × 1.5 mm through-plane 5 mm, standard 1.8 × 1.8 x 8mm and low 3.0 × 3.0 x 10mm). CMR-FT comprised left ventricular (LV) global and segmental longitudinal/circumferential strain (GLS/GCS) and associated systolic strain rates (SR), and right ventricular (RV) GLS.

RESULTS

Temporal but not spatial resolution did impact absolute strain and SR. Maximum absolute changes between lowest and highest temporal resolution were as follows: 1.8% and 0.3%/s for LV GLS and SR, 2.5% and 0.6%/s for GCS and SR as well as 1.4% for RV GLS. Changes of strain values occurred comparing 20 and 30 frames/cardiac cycle including LV and RV GLS and GCS (p < 0.001-0.046). In contrast, SR values (LV GLS/GCS SR) changed significantly comparing all successive temporal resolutions (p < 0.001-0.013). LV strain and SR reproducibility was not affected by either temporal or spatial resolution, whilst RV strain variability decreased with augmentation of temporal resolution.

CONCLUSION

Temporal but not spatial resolution significantly affects strain and SR in CMR-FT deformation analyses. Strain analyses require lower temporal resolution and 30 frames/cardiac cycle offer consistent strain assessments, whilst SR measurements gain from further increases in temporal resolution.

Assessment of myocardial deformation with CMR: a comparison with ultrasound speckle tracking

OBJECTIVES

Myocardial deformation integrated with cardiac dimensions provides a comprehensive assessment of cardiac function, which has proven useful to differentiate cardiac pathology from physiological adaptation to situations such as chronic intensive training. Feature tracking (FT) can measure myocardial deformation from cardiac magnetic resonance (CMR) cine sequences; however, its accuracy is not yet fully validated. Our aim was to compare the accuracy and reproducibility of FT with speckle tracking echocardiography (STE) in highly trained endurance athletes.

METHODS

Ninety-three endurance athletes (> 12-h training/week during the last 5 years, 52% male, 35 ± 5.1 years old) and 72 age-matched controls underwent resting CMR and transthoracic echocardiography to assess biventricular exercise-induced remodeling and biventricular global longitudinal strain (GLS) by CMR-FT and STE.

RESULTS

Strain values were significantly lower when assessed by CMR-FT compared to STE (p < 0.001), with good reproducibility for the left ventricle (bias = 3.94%, limit of agreement [LOA] = ± 4.27 %) but wider variability for right ventricle strain. Strain values by both techniques proportionally decreased with increasing ventricular volumes, potentially depicting the functional biventricular reserve that characterizes athletes' hearts.

CONCLUSIONS

Biventricular longitudinal strain values were lower when assessed by FT as compared to STE. Both methods were statistically comparable when measuring LV strain but not RV strain. These differences might be justified by the lower in-plane spatial and temporal resolution of FT, which is particularly relevant for the complex anatomy of the RV.

KEY POINTS

• Strain values were significantly lower when assessed by FT as compared to STE, which was expected due to the lower in-plane spatial and temporal resolution of FT versus STE. • Both methods were statistically comparable when measuring LV strain but not for RV strain analysis. • Characterizing the normal ranges and reproducibility of strain metrics by FT is an important step toward its clinical applicability, since it can be assessed offline and applied to routinely acquired cine CMR images.

CMR feature tracking strain patterns and their association with circulating cardiac biomarkers in patients with hypertrophic cardiomyopathy

Aims

CMR feature tracking strain (CMR-FT) provides prognostic information. However, there is a paucity of data in hypertrophic cardiomyopathy (HCM). We sought to analyze global CMR-FT parameters in all four cardiac chambers and to assess associations with NT-proBNP and cardiac troponin T (hsTnT) in patients with HCM.

Methods

This retrospective study included 144 HCM patients and 16 healthy controls with CMR at 1.5 T. Analyses were performed on standard steady-state free precession cine (SSFP) CMR data using a commercially available software. Global left ventricular (LV) strain was assessed as longitudinal (LV_LAX-GLS), circumferential (LV_LAX-GCS) and radial strain (LV_LAX-GRS) on long -axis (LAX) and as LV_SAX-GCS and LV_SAX-GRS on short- axis (SAX). Right ventricular (RV-GLS), left atrial (LA-GLS) and right atrial (RA-GLS) strain were assessed on LAX.

Results

We found LV_LAX-GLS [− 18.9 (− 22.0, − 16.0), − 23.5 (− 25.5, − 22.0) %, p = 0.0001), LV_SAX-GRS [86.8 (65.9–115.5), 119.6 (91.3–143.7) %, p = 0.001] and LA_LAX-GLS [LA_2CH-GLS 29.2 (19.1–37.7), LA_2CH-GLS 38.2 (34.3–47.1) %, p = 0.0036; LA_4CH-GLS 22.4 (14.6–30.7) vs. LA_4CH-GLS 33.4 (28.4–37.3) %, p = 0.0033] to be impaired in HCM compared to healthy controls despite normal LVEF. Furthermore, LV and LA strain parameters were impaired in HCM with elevated NT-proBNP and/or hsTnT, despite preserved LVEF compared to HCM with normal biomarker levels. There was a moderate correlation of LV and LA CMR-FT with levels of NT-proBNP and hsTnT.

Conclusion

CMR-FT reveals LV and LA dysfunction in HCM despite normal LVEF. The association between impaired LV strain and elevated NT-proBNP and hsTnT indicates a link between unapparent functional abnormalities and disease severity in HCM.

Graphic abstract

Typical CMR-FT findings in patients with hypertrophic cardiomyopathy

Potential Role of Artificial Intelligence in Cardiac Magnetic Resonance Imaging: Can It Help Clinicians in Making a Diagnosis?

In the era of modern medicine, artificial intelligence (AI) is a growing field of interest which is experiencing a steady development. Several applications of AI have been applied to various aspects of cardiac magnetic resonance to assist clinicians and engineers in reducing the costs of exams and, at the same time, to improve image acquisition and reconstruction, thus simplifying their analysis, interpretation, and decision-making process as well. In fact, the role of AI and machine learning in cardiovascular imaging relies on evaluating images more quickly, improving their quality, nulling intraobserver and interobserver variability in their interpretation, upgrading the understanding of the stage of the disease, and providing with a personalized approach to cardiovascular care. In addition, AI algorithm could be directed toward workflow management. This article presents an overview of the existing AI literature in cardiac magnetic resonance, with its strengths and limitations, recent applications, and promising developments. We conclude that AI is very likely be used in all the various process of diagnosis routine mode for cardiac care of patients.

Role of cardiovascular magnetic resonance imaging in cardio-oncology

Advances in cancer therapy have led to significantly longer cancer-free survival times over the last 40 years. Improved survivorship coupled with increasing recognition of an expanding range of adverse cardiovascular effects of many established and novel cancer therapies has highlighted the impact of cardiovascular disease in this population. This has led to the emergence of dedicated cardio-oncology services that can provide pre-treatment risk stratification, surveillance, diagnosis, and monitoring of cardiotoxicity during cancer therapies, and late effects screening following completion of treatment. Cardiovascular imaging and the development of imaging biomarkers that can accurately and reliably detect pre-clinical disease and enhance our understanding of the underlying pathophysiology of cancer treatment-related cardiotoxicity are becoming increasingly important. Multi-parametric cardiovascular magnetic resonance (CMR) is able to assess cardiac structure, function, and provide myocardial tissue characterization, and hence can be used to address a variety of important clinical questions in the emerging field of cardio-oncology. In this review, we discuss the current and potential future applications of CMR in the investigation and management of cancer patients.

Cardiovascular magnetic resonance-determined left ventricular myocardium impairment is associated with C-reactive protein and ST2 in patients with paroxysmal atrial fibrillation

BACKGROUND

Myocardial strain assessed with cardiovascular magnetic resonance (CMR) feature tracking can detect early left ventricular (LV) myocardial deformation quantitatively in patients with a variety of cardiovascular diseases, but this method has not yet been applied to quantify myocardial strain in patients with atrial fibrillation (AF) and no coexistent cardiovascular disease, i.e., the early stage of AF. This study sought to compare LV myocardial strain and T1 mapping indices in AF patients and healthy subjects, and to investigate the associations of a portfolio of inflammation, cardiac remodeling and fibrosis biomarkers with LV myocardial strain and T1 mapping indices in AF patients with no coexistent cardiovascular disease.

METHODS

The study consisted of 80 patients with paroxysmal AF patients and no coexistent cardiovascular disease and 20 age- and sex-matched healthy controls. Left atrial volume (LAV), LV myocardial strain and native T1 were assessed with CMR, and compared between the AF patients and healthy subjects. Biomarkers of C-reactive protein (CRP), transforming growth factor beta-1 (TGF-β1), collagen III N-terminal propeptide (PIIINP), and soluble suppression of tumorigenicity 2 (sST2) were obtained with blood tests, and compared between the AF patients and healthy controls. Associations of these biomarkers with those CMR-measured parameters were analyzed for the AF patients.

RESULTS

For the CMR-measured parameters, the AF patients showed significantly larger LAV and LV end-systolic volume, and higher native T1 than the healthy controls (max P = 0.027). The absolute values of the LV peak systolic circumferential strain and its rate as well as the LV diastolic circumferential strain rate were all significantly reduced in the AF patients (all P < 0.001). For the biomarkers, the AF patients showed significantly larger CRP (an inflammation biomarker) and sST2 (a myocardium stiffness biomarker) than the controls (max P = 0.007). In the AF patients, the five CMR-measured parameters of LAV, three LV strain indices and native T1 were all significantly associated with these two biomarkers of CRP and sST2 (max P = 0.020).

CONCLUSIONS

In patients with paroxysmal AF and no coexistent cardiovascular disease, LAV enlargement and LV myocardium abnormalities were detected by CMR, and these abnormalities were associated with biomarkers that reflect inflammation and myocardial stiffness.

Hyperparameter optimisation and validation of registration algorithms for measuring regional ventricular deformation using retrospective gated computed tomography images

Recent dose reduction techniques have made retrospective computed tomography (CT) scans more applicable and extracting myocardial function from cardiac computed tomography (CCT) images feasible. However, hyperparameters of generic image intensity-based registration techniques, which are used for tracking motion, have not been systematically optimised for this modality. There is limited work on their validation for measuring regional strains from retrospective gated CCT images and open-source software for motion analysis is not widely available. We calculated strain using our open-source platform by applying an image registration warping field to a triangulated mesh of the left ventricular endocardium. We optimised hyperparameters of two registration methods to track the wall motion. Both methods required a single semi-automated segmentation of the left ventricle cavity at end-diastolic phase. The motion was characterised by the circumferential and longitudinal strains, as well as local area change throughout the cardiac cycle from a dataset of 24 patients. The derived motion was validated against manually annotated anatomical landmarks and the calculation of strains were verified using idealised problems. Optimising hyperparameters of registration methods allowed tracking of anatomical measurements with a mean error of 6.63% across frames, landmarks, and patients, comparable to an intra-observer error of 7.98%. Both registration methods differentiated between normal and dyssynchronous contraction patterns based on circumferential strain (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p_1=0.0065$$\end{document}p1=0.0065, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p_2=0.0011$$\end{document}p2=0.0011). To test whether a typical 10 temporal frames sampling of retrospective gated CCT datasets affects measuring cardiac mechanics, we compared motion tracking results from 10 and 20 frames datasets and found a maximum error of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$8.51\pm 0.8\%$$\end{document}8.51±0.8%. Our findings show that intensity-based registration techniques with optimal hyperparameters are able to accurately measure regional strains from CCT in a very short amount of time. Furthermore, sufficient sensitivity can be achieved to identify heart failure patients and left ventricle mechanics can be quantified with 10 reconstructed temporal frames. Our open-source platform will support increased use of CCT for quantifying cardiac mechanics.

Myocardial Deformation Assessed by MR Feature Tracking in Groups of Patients With Ischemic Heart Disease

BACKGROUND

Global myocardial strain assessments have been shown to provide useful measures of contractility in many diseases, but whether feature tracking (FT)-derived strain at rest can differentiate ischemic myocardium from infarcted and remote myocardium in patients with coronary artery disease (CAD) remains unclear.

PURPOSE

To evaluate the performance of magnetic resonance imaging FT-derived strain in the detection of regional myocardial deformation in ischemic, infarcted, and apparent normal myocardium in CAD.

STUDY TYPE

Retrospective POPULATION: A total of 109 patients with CAD.

FIELD STRENGTH/SEQUENCES

Steady-state free-precession rest cine, T1-weighted saturation-recovery fast gradient echo stress/rest perfusion, and two-dimensional phase-sensitive inversion recovery breath-hold late gadolinium enhancement (LGE) tests were performed at 3.0 T.

ASSESSMENT

Based on perfusion and LGE images, left ventricular (LV) myocardial segments of CAD patients were categorized into ischemic, infarcted, and negative groups. The FT longitudinal (LS) and circumferential strain (CS) of normal subjects and the three CAD groups were calculated. Z-scores of each segment of CAD patients were calculated.

STATISTIC TESTS

χ² testing, analysis of variance (ANOVA), and Kruskal-Wallis tests. Z-scores were used to compare the strain between CAD groups.

RESULTS

There were significant differences in global LS (GLS) and CS (GCS) between healthy controls (GLS: -19.0% ± 1.4%, GCS, -20.9% ± 1.8%), ischemia (GLS: -17.4% ± 2.1%, GCS, -19.6% ± 1.9%), infarction (GLS: -16.4% ± 1.9%, GCS, -17.8% ± 1.9%), and negative patients (GLS: -17.7% ± 1.4%, GCS, -20.9% ± 2.4%) (all P < 0.05). There were significant differences in regional LS and CS between ischemic (LS, -16.1% ± 5.0%, CS, -18.7% ± 5.0%), infarcted (LS, -14.8% ± 5.2%, CS, -15.3% ± 4.8%), and negative segments (LS, -17.6% ± 5.2%, CS, -19.8% ± 4.8%) (all P < 0.05). The differences in the z-scores of regional LS and CS between the ischemic, infarcted, and negative segments were also significant (all P < 0.05).

DATA CONCLUSION

FT-derived rest strain indices of the LV myocardium of CAD patients were higher compared to healthy controls and varied between ischemic, infarcted, and negative segments.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 5.

Left ventricular reverse remodeling and function by strain analysis in aortic stenosis: A CMR analysis of the EPICHEART study

INTRODUCTION AND OBJECTIVES

In severe aortic stenosis (AS), the impact of aortic valve replacement (AVR) on left ventricular (LV) systolic function assessed by strain and measured by echocardiography or cardiac magnetic resonance (CMR) has been controversial. We aimed to investigate LV systolic myocardial function changes six months after AVR using global longitudinal (GLS), circumferential (GCS) and radial (GRS) strain derived from CMR imaging.

METHODS

We included 39 severe AS patients (69.3±7.8 years; 61.5% male) with preserved LV ejection fraction (LVEF) who were recruited as part of the EPICHEART study and underwent successful AVR (aortic valvular area: 0.8 cm² (IQR: 0.2) pre- to 1.8 cm² (IQR:0.5) post-AVR). Structural and functional parameters were assessed at baseline and six months after AVR, including LV GRS, GCS and GLS analysis by CMR, using cine short-axial and two-, three-, and four-chamber long-axial view. Comparison between baseline and postoperative LV remodeling was performed using Student t-test and Wilcoxon test.

RESULTS

At six-month follow-up, LV mass, end-diastolic and end-systolic volumes, stroke volume, cardiac output, lateral E/e', tricuspid annular plane systolic excursion, right ventricular (RV) S wave velocity, GLS [-15.6% (IQR: 4.39) to -13.7% (IQR: 4.62)] and GCS [-17.8±3.58% to -16.1±2.94%] reduced significantly, while LVEF and GRS remained unchanged and lateral e' velocity increased.

CONCLUSIONS

Despite favorable reverse LV structural and diastolic functional remodeling six months following AVR, GLS and GCS assessed by CMR reduced compared to baseline, LVEF remained unchanged. The clinical utility and timing of assessment of postoperative strain changes as a marker of systolic function progression needs further research.

Endovascular reversal of renovascular hypertension blunts cardiac dysfunction and deformation in swine

OBJECTIVE

Renovascular hypertension (RVH) induces hemodynamic and humoral aberrations that may impair cardiac function, structure and mechanics, including cardiac twist and deformation. Revascularization of a stenotic renal artery can decrease blood pressure (BP), but its ability to restore cardiac mechanics in RVH remains unclear. We hypothesized that percutaneous transluminal renal angioplasty (PTRA) would improve cardiac function and left ventricular (LV) deformation in swine RVH.

METHODS

Seventeen domestic pigs were studied for 16 weeks: RVH, RVH + PTRA and normal controls (n = 5-6 each). Global LV function was estimated by multidetector computed-tomography, and LV deformation by electrocardiographically triggered MRI tagging at the apical, mid, and basal LV levels. Cardiomyocyte hypertrophy, myocardial capillary density, and fibrosis were evaluated ex vivo.

RESULTS

BP and wall thickness were elevated in RVH and decreased by PTRA, yet remained higher than in controls. LV myocardial muscle mass increased in RVH pigs, which also developed diastolic dysfunction, whereas cardiac output increased. Furthermore, both apical rotation and peak torsion angle increased in RVH compared with controls. Ex vivo, RVH induced myocardial fibrosis and vascular rarefaction. PTRA restored cardiac function and alleviated hypertrophy, vascular rarefaction, and fibrosis. PTRA also normalized apical rotation and peak torsion angle, and elevated basal peak radial strain and apical peak radial strain compared with RVH.

CONCLUSION

In addition to cardiac LV adaptive hypertrophy and diastolic dysfunction, short-term RVH causes cardiac deformation. Despite only partial improvement in BP, PTRA effectively restored cardiac function and reversed abnormal mechanics. Hence, renal revascularization may be a useful strategy to preserve cardiac function in RVH.

Cardiac magnetic resonance image diagnosis of hypertrophic obstructive cardiomyopathy based on a double-branch neural network

OBJECTIVE

Cardiac magnetic resonance (CMR) imaging is a well-established technique for diagnosis of hypertrophic obstructive cardiomyopathy (HOCM) and evaluation of cardiac function, but the process is complicated and time consuming. Therefore, this paper proposes a cardiomyopathy recognition algorithm using a multi-task learning mechanism and a double-branch deep learning neural network.

METHOD

We implemented a double-branch neural network CMR-based HOCM recognition algorithm. Compared with the traditional classification algorithms such as the ResNet, DenseNet network, contrast the accuracy of network classification of cardiomyopathy is higher by 10.11%.

RESULT

The loss curve of the algorithm basically converges in 100 rounds, and the convergence speed of the algorithm is twice that of the traditional algorithm. The accuracy of this algorithm to classify cardiomyopathy is 96.79%, and the sensitivity is 95.24%, which is 10.11% higher than the conventional algorithm.

CONCLUSION

The CMR imaging automatic recognition algorithm for HOCM capture static morphological and motion characteristics of the heart, and comprehensively enhances recognition accuracy when the sample size is limited.

In Vitro Methods to Model Cardiac Mechanobiology in Health and Disease

In vitro cardiac modeling has taken great strides in the past decade. While most cell and engineered tissue models have focused on cell and tissue contractile function as readouts, mechanobiological cues from the cell environment that affect this function, such as matrix stiffness or organization, are less well explored. In this study, we review two-dimensional (2D) and three-dimensional (3D) models of cardiac function that allow for systematic manipulation or precise control of mechanobiological cues under simulated (patho)physiological conditions while acquiring multiple readouts of cell and tissue function. We summarize the cell types used in these models and highlight the importance of linking 2D and 3D models to address the multiscale organization and mechanical behavior. Finally, we provide directions on how to advance in vitro modeling for cardiac mechanobiology using next generation hydrogels that mimic mechanical and structural environmental features at different length scales and diseased cell types, along with the development of new tissue fabrication and readout techniques. Impact statement Understanding the impact of mechanobiology in cardiac (patho)physiology is essential for developing effective tissue regeneration and drug discovery strategies and requires detailed cause-effect studies. The development of three-dimensional in vitro models allows for such studies with high experimental control, while integrating knowledge from complementary cell culture models and in vivo studies for this purpose. Complemented by the use of human-induced pluripotent stem cells, with or without predisposed genetic diseases, these in vitro models will offer promising outlooks to delineate the impact of mechanobiological cues on human cardiac (patho)physiology in a dish.

Changes in strain parameters at different deterioration levels of left ventricular function: A cardiac magnetic resonance feature-tracking study of patients with left ventricular noncompaction

BACKGROUND

There is a lack of cardiac MRI information on left ventricular (LV) strain and rotational parameters of left ventricular noncompaction (LVNC) patients with reduced ejection fraction (EF). Thus, we sought to use feature tracking (FT) to describe these changes at different levels of EF deterioration.

METHODS

We included 31 adult LVNC patients with reduced LV EF (Group B, EF < 50%) without any comorbidities or concomitant cardiac diseases, 31 age- and sex-matched LVNC patients with good EF (Group A, EF > 50%) and 31 healthy controls. Group B was divided according to LV EF into two subgroups (Group B-1: EF 35-50%, Group B-2: EF < 35%). Their global longitudinal, circumferential (GCS), and radial (GRS) strains; LV segmental strains; LV apical and basal rotation values; and patterns and degree of LV dyssynchrony were measured.

RESULTS

All of the global and mean segmental strain parameters were significantly worse in Groups B, B-1 and B-2 than in Group A and in the controls. The LV mechanical dispersion increased as LV EF decreased. The degree of apical rotation was the highest in the control group, almost the same in Group A and the lowest and in the reverse direction in Group B-2. A rotational pattern, clockwise-directed rigid body rotation (RBR), was found in 39% of the Group B patients, and a counterclockwise-directed RBR was found in 26% of the Group A patients.

CONCLUSIONS

The strain values and rotational parameters changed as the EF decreased. These changes affected the global LV, and we did not identify an LVNC-specific strain pattern.

Myocardial strain in nonischemic dilated cardiomyopathy with feature tracking. Feasibility and prognostic implications

INTRODUCTION AND OBJECTIVES

Myocardial strain analysis could provide additional information to left ventricular ejection fraction (LVEF) in nonischemic dilated cardiomyopathy (NIDC). Our aim was to analyze the feasibility of left ventricular strain evaluation using cardiac magnetic resonance feature tracking (FT) in NIDC, and to determine its clinical and prognostic impact.

METHODS

We retrospectively included consecutive patients with NIDC who underwent cardiac magnetic resonance. Left ventricular global longitudinal, circumferential and radial strain were obtained from standard cine sequences using FT analysis software. We evaluated their association with a composite endpoint (heart failure, implantable cardioverter-defibrillator in secondary prevention, or death).

RESULTS

FT analysis could be performed in all of the 98 patients (mean age 68±13 years, 72% men). Intra- and interobserver concordance was good for global longitudinal and circumferential strain but was worse for radial strain. Global circumferential strain was independently associated (OR, 1.16; P=.045) with LVEF normalization during follow-up and was the only morphological parameter independently associated with the composite endpoint (OR, 1.15; P=.038). A cutoff value <-8.2% was able to predict the incidence of this event during follow-up (log-rank 4.6; P=.032).

CONCLUSIONS

Left ventricular strain analysis with FT is feasible and reproducible in NIDC. Global circumferential strain was able to predict LVEF recovery and the appearance of major cardiovascular events during follow-up.

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

Background

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

Methods

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

Results

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

Conclusions

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

Negative Impact of the Left Ventricular Remnant Morphology on Systemic Right Ventricular Myocardial Deformation in Hypoplastic Left Heart Syndrome

Left ventricular (LV) morphology may affect right ventricular (RV) function before and after Fontan palliation in patients with hypoplastic left heart syndrome (HLHS). We sought to assess the potential impact of LV morphology on RV function in patients with HLHS using cardiac magnetic resonance (CMR) imaging. A retrospective analysis of available CMR scans from all patients with HLHS was performed. LV morphology was categorized as absent/slit-like or globular/miniaturized. Volumetric analysis was performed using manual disc-summation method on steady-state free precession (SSFP) stack obtained in short-axis orientation of the ventricles. 4-chamber and short-axis SSFP images were used to measure strain on a semi-automated feature-tracking (FT) module. Two sample t-test was used to compare the groups. A total of 48 CMR scans were analyzed. Of those, 12 patients had absent/slit-like and 36 had globular/miniaturized LV morphology. Averaged 4-chamber longitudinal RV strain was significantly higher for absent/slit-like (- 17.6 ± 4.7%) than globular/miniaturized (- 13.4 ± 3.5; P = 0.002). Averaged 4-chamber radial RV strain was also significantly higher for absent/slit-like (33.1 ± 14.9%) than globular/miniaturized (21.6 ± 7.1; P = 0.001). For globular/miniaturized LV morphology, the decreases of 4-chamber longitudinal and radial strains were mainly attributable to the septal basilar and septal mid-ventricular segments. No differences were found in short-axis RV global circumferential strain between the morphologic subtypes (absent/slit-like - 15.0 ± 6.5, globular/miniaturized - 15.7 ± 4.7; P = 0.68). Larger LV remnants, with globular/miniaturized LV morphology, demonstrated diminished strain in the septal base and mid-ventricle segments. Patients with globular/miniaturized LV morphology may benefit with closer monitoring and lower threshold to start heart failure medications. These results exemplify the utility of including both septal and regional deformation in systemic RV strain analysis.

Quantitative assessment of left ventricular longitudinal function and myocardial deformation in Duchenne muscular dystrophy patients

Background

Duchenne muscular dystrophy (DMD) manifests in males mainly by skeletal muscle impairment, but also by cardiac dysfunction. The assessment of the early phases of cardiac involvement using echocardiography is often very difficult to perform in these patients. The aim of the study was to use cardiac magnetic resonance (CMR) strain analysis and mitral annular plane systolic excursion (MAPSE) in the detection of early left ventricular (LV) dysfunction in DMD patients.

Methods and results

In total, 51 male DMD patients and 18 matched controls were examined by CMR. MAPSE measurement and functional analysis using feature tracking (FT) were performed. Three groups of patients were evaluated: A/ patients with LGE and LV EF < 50% (n = 8), B/ patients with LGE and LVEF ≥ 50% (n = 13), and C/ patients without LGE and LVEF ≥ 50% (n = 30). MAPSE and global LV strains of the 3 DMD groups were compared to controls (n = 18).

Groups A and B had significantly reduced values of MAPSE, global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) in comparison to controls (p < 0.05). The values of MAPSE (11.6 ± 1.9 v 13.7 ± 2.7 mm) and GCS (− 26.2 ± 4.2 v − 30.0 ± 5.1%) were significantly reduced in group C compared to the controls (p < 0.05).

Conclusion

DMD patients had decreased LV systolic function measured by MAPSE and global LV strain even in the case of normal LV EF and the absence of LGE. FT and MAPSE measurement provide sensitive assessment of early cardiac involvement in DMD patients.

Quantification of Biventricular Myocardial Strain Using CMR Feature Tracking: Reproducibility in Small Animals

Myocardial strain is a well-validated parameter for evaluating myocardial contraction. Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a novel method for the quantitative measurements of myocardial strain from routine cine acquisitions. In this study, we investigated the influence of temporal resolution on tracking accuracy of CMR-FT and the intraobserver, interobserver, and interstudy reproducibilities for biventricular strain analysis in mice from self-gated CMR at 11.7 T. 12 constitutive nexilin knockout (Nexn-KO) mice, heterozygous (Het, N = 6) and wild-type (WT, N = 6), were measured with a well-established self-gating sequence twice within two weeks. CMR-FT measures of biventricular global and segmental strain parameters were derived. Interstudy, intraobserver, and interobserver reproducibilities were investigated. For the assessment of the impact of the temporal resolution for the outcome in CMR-FT, highly oversampled semi-4 chamber and midventricular short-axis data were acquired and reconstructed with 10 to 80 phases per cardiac cycle. A generally reduced biventricular myocardial strain was observed in Nexn-KO Het mice. Excellent intraobserver and interobserver reproducibility was achieved in all global strains (ICC range from 0.76 to 0.99), where global right ventricle circumferential strain (RCSSAX) showed an only good interobserver reproducibility (ICC 0.65, 0.11-0.89). For interstudy reproducibility, left ventricle longitudinal strain (LLSLAX) was the most reproducible measure of strain (ICC 0.90, 0.71-0.97). The left ventricle radial strain (LRSSAX) (ICC 0.50, 0.10-0.83) showed fair reproducibility and RCSSAX (ICC 0.36, 0.14-0.74) showed only poor reproducibility. In general, compared with global strains, the segmental strains showed relatively lower reproducibility. A minimal temporal resolution of 20 phases per cardiac cycle appeared sufficient for CMR-FT strain analysis. The analysis of myocardial strain from high-resolution self-gated cine images by CMR-FT provides a highly reproducible method for assessing myocardial contraction in small rodent animals. Especially, global LV longitudinal and circumferential strain revealed excellent reproducibility of intra- and interobserver and interstudy measurements.

Left ventricular myocardial strain assessed by cardiac magnetic resonance feature tracking in patients with rheumatoid arthritis

Purpose

The aim of the study was to assess a relationship between the occurrence of rheumatoid arthritis (RA) and its selected clinical parameters, and left ventricular myocardial strain.

Material and methods

Fifty-six subjects were qualified for the study: 30 RA patients and 26 subjects without rheumatoid diseases. The study design included taking medical history, assessment of the disease activity using selected scales of activity, collecting samples of venous blood to assess selected laboratory parameters and the assessment of cardiac magnetic resonance (CMR). Using the feature tracking method, the following parameters of the left ventricular myocardial strain were assessed: longitudinal strain (LS), radial strain (RS) and circumferential strain (CS).

Results

Regarding global values, peak LS and peak CS were statistically significantly lower in RA patients than in the control group. In the whole study group, the factors independently related to low global LS peaks were as follows: occurrence of RA, occurrence of arterial hypertension, increased activity of antibodies against cyclic citrullinated peptide and increased concentration of neutrophil gelatinase-associated lipocalin. The occurrence of RA, occurrence of diabetes, tobacco smoking, higher activity of antibodies against cyclic citrullinated peptide and current use of methotrexate are the risk factors for low peak of global CS. The current use of steroids constitutes a protecting factor against low global CS peaks.

Conclusion

In subjects with no clinically manifested cardiac damage, RA is associated with a deteriorated left ventricular systolic function assessed by left ventricular myocardial strain measured by CMR feature tracking.