Cardiac Magnetic Resonance Feature Tracking Research Articles

Three-dimensional Feature Tracking Cardiac Magnetic Resonance in Hypertrophic Cardiomyopathy: Comparison with Two-Dimensional Algorithm

Abstract Aim The aims of this study were to: 1) determine whether 2D and 3D feature tracking cardiac magnetic resonance (FT-CMR) are equivalent in patients with hypertrophic cardiomyopathy (HCM), 2) compare 3D FT-CMR values in HCM and healthy volunteers and 3) compare FT-CMR in most frequent HCM phenotypes. Methods Consecutive patients with HCM and LVEF>55% were included in the study. FT-CMR parameters included left ventricular (LV) global longitudinal (GLS), circumferential (GCS) and radial (GRS) strain, which were calculated using both 2D and 3D FT-CMR derived from multi-slice 2D cine image stacks in the LV short and long axis plane. FT was calculated using Circle Cvi42 software. Results Sixty HCM patients (66.7% male, mean age 58.2 ± 15.8 years) were included (56.7% septal HCM, 25% apical HCM). FT analysis was feasible in all individuals. Seventy-two percent of patients exhibited focal fibrosis in 2 [0-4] segments. As previously reported for healthy individuals, myocardial strain evaluated using 3D FT-CMR was consistently lower compared to 2D FT-CMR. The highest level of agreement was noted between the 2D and 3D values of GCS, with a mean difference of -0.3% (95% CI -1.81 to 1.2, p=0.68), while GRS showed the lowest agreement. In patients with apical HCM GLS 3D was significantly more reduced than in patients with septal HCM (-7.4% ± 4.1 vs. -10.5% ± 2.9, p=0.004). Conclusions 3D FT-CMR is feasible in HCM patients. 3D FT is advantageous as it does not require additional scanning time, making it suitable for HCM patients with limited acoustic window and abnormal geometry.

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

BackgroundCurrent mainstream cardiovascular magnetic resonance-feature tracking (CMR-FT) methods, including optical flow and pairwise registration, often suffer from the drift effect caused by accumulative tracking errors. Here, we developed a CMR-FT method based on deformable groupwise registration with a locally low-rank (LLR) dissimilarity metric to improve myocardial tracking and strain estimation accuracy.MethodsThe proposed method, Groupwise-LLR, performs feature tracking by iteratively updating the entire displacement field across all cardiac phases to minimize the sum of the patchwise signal ranks of the deformed movie. The method was compared with alternative CMR-FT methods including the Farneback optical flow, a sequentially pairwise registration method, and a global low rankness-based groupwise registration method via a simulated dataset (n = 20), a public cine data set (n = 100), and an in-house tagging-MRI patient dataset (n = 16). The proposed method was also compared with two general groupwise registration methods, nD + t B-Splines and pTVreg, in simulations and in vivo tracking.ResultsOn the simulated dataset, Groupwise-LLR achieved the lowest point tracking errors (p = 0.13 against pTVreg for the temporally averaged point tracking errors in the long-axis view, and p < 0.05 for all other cases), voxelwise strain errors (all p < 0.05), and global strain errors (p = 0.05 against pTVreg for the longitudinal global strain errors, and p < 0.05 for all other cases). On the public dataset, Groupwise-LLR achieved the lowest contour tracking errors (all p < 0.05), reduced the drift effect in late-diastole, and preserved similar inter-observer reproducibility as the alternative methods. On the patient dataset, Groupwise-LLR correlated better with tagging-MRI for radial strains than the other CMR-FT methods in multiple myocardial segments and levels.ConclusionsThe proposed Groupwise-LLR reduces the drift effect and provides more accurate myocardial tracking and strain estimation than the alternative methods. The method may thus facilitate a more accurate estimation of myocardial strains for clinical assessments of cardiac function.

Myocardial strain analysis by cardiac magnetic resonance associated with arrhythmias in repaired tetralogy of Fallot patients

BackgroundEvaluating myocardial function using cardiac magnetic resonance (CMR) feature tracking provides a comprehensive cardiac assessment, particularly a detailed evaluation for patients with repaired tetralogy of Fallot (rTOF). This study aimed to identify factors associated with arrhythmias in rTOF patients utilizing conventional CMR techniques, including myocardial strain measurements.MethodsThis single-center, retrospective study included 245 rTOF patients who underwent CMR between 2017 and 2023. Patients were stratified based on the presence or absence of arrhythmias during follow-up. The biventricular strain was assessed using CMR-derived feature tracking. Demographic, clinical, and imaging data were collected, and statistical analyses were performed to identify factors associated with arrhythmic events.ResultsThe median age at surgery was 5.6 years (range 1–44 years), with the median age at CMR was 27.5 years (range 15–69 years). Over the follow-up period, 25 patients (10.2%) experienced atrial or ventricular arrhythmias. Univariate analysis revealed significant associations between arrhythmic events and older age at surgery and CMR, lower functional class, larger heart size on chest radiograph, and prolonged QRS duration (QRSd). Additionally, arrhythmias were associated with increased right ventricular (RV) volume, reduced RV and left ventricular (LV) ejection fraction (EF), and impaired strain values. Multivariate binary logistic regression, adjusting for age at surgery, NYHA class, QRSd, and cardiothoracic ratio, identified that a lower RV EF (adjusted odds ratio [aOR] 6.97), RV global radial strain (GRS) (aOR 6.68), RV global circumferential strain (GCS) (aOR 6.36), RV global longitudinal strain (GLS) (aOR 3.14), and LV GRS (aOR 3.02) were all significantly associated with arrhythmias.ConclusionThis study highlights the significant contribution of CMR-derived myocardial strain measurements in predicting arrhythmic events in patients with rTOF. In addition to conventional RV EF, strain metrics—particularly those of the right ventricle- emerged as strong, independent predictors of arrhythmias, offering valuable prognostic information for clinical management in this patient population. These findings underscore the importance of myocardial strain analysis as a complementary tool to conventional imaging in evaluating arrhythmic risk in rTOF patients.Clinical trial numberNot applicable.

Accuracy of left ventricular mechanical dyssynchrony indices for mechanical characteristics of left bundle branch block using cardiovascular magnetic resonance feature tracking.

More than 90% of patients with left bundle branch block (LBBB) and reduced left ventricular (LV) ejection fraction have LV dyssynchrony and a high probability of response to cardiac resynchronization therapy (CRT). A subgroup of patients with non-specific intraventricular conduction delay (IVCD) have a LBBB-like LV activation pattern when studied using invasive mapping and advanced echocardiographic techniques. These patients also frequently benefit from CRT but these patients have proven difficult to identify using ECG criteria. Cardiovascular magnetic resonance (CMR) imaging indices of dyssynchrony may identify patients with IVCD who may benefit from CRT but their relative accuracies for identification of LV dyssynchrony remains unknown. We compared the LV dyssynchrony classification accuracy of two commonly available CMR indices in a study population of patients with severely reduced LV ejection fraction and no scar, and either LBBB or normal conduction (normal QRS duration and axis, controls). In LBBB (n=44) and controls (n=36), using CMR feature-tracking circumferential strain, dyssynchrony was quantified as the circumferential uniformity ratio estimate (CURE) and the systolic stretch index (SSI). Deidentified CMR image-data were made publicly available. Both CURE and SSI quantified more severe dyssynchrony in LBBB compared to controls (p<0.001 for both). SSI more frequently discriminated LBBB and normal conduction LV activation patterns than CURE (area under the receiver-operating characteristics curve [95% confidence interval] 0.96 [0.92-1.00] for SSI vs 0.76 [0.65-0.86] for CURE, p<0.001). SSI is superior to CURE for discriminating synchronous and dyssynchronous LV activation and should be further studied in the setting of non-LBBB conduction abnormalities.

Prognostic Value of Left Ventricular Myocardial Strain Parameters Derived from Cardiac Magnetic Resonance Feature Tracking Technique in Light-Chain Cardiac Amyloidosis Patients: A Pilot Study.

Previous research on the prognostic implications of left ventricular myocardial strain using cardiac magnetic resonance feature tracking (CMR-FT) in light-chain cardiac amyloidosis (AL-CA) has shown promising potential. This study aimed to evaluate the prognostic significance of global and segmental left ventricular myocardial strain in AL-CA patients, specifically analyzing the American Heart Association's 16 segments. A total of 75 consecutive patients (50 men, mean age: 55.6 ± 10.0 years) who underwent CMR examination with histologically confirmed systemic AL-CA were retrospectively enrolled between January 2014 and November 2022. Both global and segmental myocardial strain and the American Heart Association's 16 segments were quantified using CMR-FT on the steady-state free precession (SSFP) cine sequence. A comparative analysis was conducted between survivors and non-survivors based on the defined endpoint. Student t-test or Mann-Whitney U, receiver operating characteristic curve, Kaplan-Meier event-free survival curve, and Cox proportional hazards regression were used. Significance was set at p < 0.05. Following a median follow-up of 34 months, 16 out of 75 patients experienced mortality events. B-type natriuretic peptides (BNP) (p < 0.001), global radial strain (RSglobal) (p = 0.033), and RS in the basal inferior segment (RSbas-inferior) (p = 0.025) remained significant as independent predictors of all-cause mortality. The cut-off values were identified as 24.97% for RSglobal, and 20.97% for RSbas-inferior. Kaplan-Meier survival curves revealed significantly reduced event-free survival for individuals in the lower cut-off groups for RSglobal and RSbas-inferior (p = 0.013, p < 0.001, respectively). Radial strain for the global and the basal inferior segment may prove valuable for risk stratification in patients with AL-CA.

Abstract 4121348: Impairments in Left Atrioventricular Coupling Underpins Reductions in Skeletal Muscle Mass and Function in Ageing Older Adults

Background: Age-related cardiovascular disease (CVD) may manifest with changes in left ventricular (LV) systolic or left atrial (LA) dysfunction. Alterations in functional performance between the LV and LA chambers characterized by LA-LV coupling may be a sensitive marker representative of impairments in global cardiac performance, compared to either chamber alone. The increasing relevance of skeletal muscle function towards cardiac health in ageing, motivated our current work that investigated associations between skeletal muscle function and LA-LV coupling. Aim : Using advanced cardiac magnetic resonance (CMR) that characterizes cardiac volumetric parameters and strain functions, we determined the association between handgrip strength (HGS) and appendicular lean mass (ALM) with left atrioventricular coupling index (LACI). Methods: Community older adults without CVD underwent simultaneous assessment of HGS by hand dynamometer, height-square adjusted ALM by bio-impedance, and LA phasic function (namely reservoir, conduit, booster strain) as well as LA and LV volumetric parameters by CMR feature tracking. LACI is defined as the ratio of the ratio of LA to LV end-diastolic volumes. We performed linear regression and multivariable logistic regression to examine the relationship between HGS/ALM and LACI. Results: Among 251 study participants (mean age: 71 ± 9.1 years, female 44.7%), 149 (59%) had impaired LACI. HGS was linearly associated with LACI (β=-0.004, p=0.003) and LVEDV (β=1.62, p&lt;0.0001), and ALM was linearly associated with LA volume (β=0.55, p=0.018) and LVEDV (β=3.45, p&lt;0.0001) (Figure.1). Participants with impaired LACI (&gt; 25%) had lower HGS (mean=22.8 ± 7.1 kg vs 26.1 ± 6.4 kg, p= 0.0002), lower ALM (16.4 ± 4.2 kg/m2 vs 17.7 ± 3.8 kg/m2, p=0.014), higher LA volume (36.8 ± 15.2 ml vs 22.0 ± 5.5 ml, p &lt; 0.0001) and lower LV end-diastolic volume (101.0 ± 24.2 ml vs 111.9 ± 27.3 ml, p = 0.0011). The association between impaired LA-LV coupling and lower HGS (β=-0.0647, 95%CI -0.0255, -0.1040, p=0.001) and lower ALM (β=-0.0776, 95%CI -0.0107, -0.1444, p=0.011) persisted after adjusting for age. Conclusion: Reduced HGS and ALM among community-dwelling older adults was associated with impaired LA-LV coupling suggestive of underlying early-stage LA remodelling and impairments in left atrioventricular compliance. Detection of reduced HGS and ALM in community cohorts may prompt early identification of older adults at risk of dysfunctional cardiac aging.

Myocardial Strain Assessment for Early Duchenne Muscular Dystrophy Diagnosis in Pediatric Patients Using Cardiac MRI

Assessing myocardial strain remains challenging, particularly in the pediatric population, due to the smaller heart sizes, higher heart rates, and variability in strain parameters compared to adult populations. This study aimed to investigate the utility of myocardial strain measurements using cardiac magnetic resonance-feature tracking (CMR-FT) for early diagnosis of Duchenne muscular dystrophy (DMD) in pediatric patients. Twenty-eight DMD patients and 20 healthy controls were involved in this study. Global circumferential, longitudinal, and radial strain (GCS, GLS, and GRS) were measured for the left ventricle (LV) using CMR-FT. Segmental strain values only of the inferolateral and anterolateral LV segments in DMD patients without late gadolinium enhancement (LGE) and DMD patients with LGE were compared to the healthy controls. Strain measurements using CMR-FT in DMD patients were considerably lower than those of healthy controls, with all p-values lower than 0.001. DMD patients without LGE showed decreased inferolateral and anterolateral segmental values only relative to healthy controls. The same behavior was maintained for the LV geometry. Multivariable linear regression demonstrated that the end-systole (ES) wall thicknesses and thickening were associated with decreased GCS and GLS. CMR-FT is crucial in detecting cardiac abnormalities in patients with DMD. It represents an innovative imaging biomarker that can detect initial myocardial alterations in DMD cardiomyopathy without relying on gadolinium.

Cardiac magnetic resonance feature tracking reveals abnormalities in patients with idiopathic ventricular fibrillation

Cardiac magnetic resonance feature tracking reveals abnormalities in patients with idiopathic ventricular fibrillation

Right ventricular global longitudinal strain by cardiac magnetic resonance feature tracking is associated with outcome in patients with a systemic right ventricle

Abstract Introduction It is well known, that patients with a systemic (sub-aortic) right ventricle (sRV) for congenitally-corrected transposition of the great arteries (TGA) or with complete TGA after atrial switch operation are more threatened to develop RV dysfunction, relevant supra- and ventricular tachycardia and have a reduced life expectancy. While the randomized, placebo-controlled, double-blinded, multi-centre SERVE trial to investigate the effect of phosphodiesterase-5 inhibitor tadalafil in sRV patients showed negative results on the primary end-point RV endsystolic volume (RVESV), aim of this sub-analysis was to evaluate RV global longitudinal strain (GLS), a more sensitive measure of RV function, by cardiac magnetic resonance (CMR) feature tracking (FT) over time, for treatment effect and to investigate whether RV GLS predicts clinical outcome in sRV patients. Methods CMR volumetric RV and FT parameters were analysed (blinded for patient and assessment time and treatment) at baseline and compared to follow-up (FU) after 3 years, or after 1 year in case of withdrawal of the study drug. FT was performed using appropriate software. Treatment effect was analysed using ANCOVA with baseline values and FU-time as covariates. Values of &amp;gt; 4th quartile of RV GLS were used as cut-off for Kaplan-Meier analysis on the primary outcome, defined as a composite of all-cause death, clinically relevant arrhythmias and hospitalisation for heart failure. Results CMR exams were available for 78 patients at baseline (40±11 years, 33% females) and for 71 patients at FU. No treatment effect of tadalafil compared to the placebo was discovered for RV GLS (p=0.26), RVESVi (p=0.63) and RV ejection fraction (RVEF, p=0.6). Over a 3 years FU-time, RV GLS mildly increased (p=0.0023, figure 1). During FU, 14 patients experienced a clinical outcome: 1 death, 4 hospitalisations for heart failure, and 12 clinically relevant arrhythmic events. An RV GLS &amp;gt; -13.4% was associated with adverse clinical outcome (p=0.003, figure 2). Conclusion In patients with a systemic RV, treatment with Tadalafil had no effect on CMR-derived RV global longitudinal strain compared to placebo. RV GLS changed significantly over the 3 years FU-time. A RV GLS value of &amp;gt; -13.4% is associated with adverse clinical outcome in these patients.Figure 1Figure 2

Prognostic value of cardiac magnetic resonance global circumferential strain assessed by feature tracking techniques in asymptomatic patients with significant aortic regurgitation

Abstract Introduction Cardiac magnetic resonance feature tracking (CMR-FT) deformation techniques have gained significant interest in recent years. They provide a comprehensive evaluation of myocardial function and improve the reproducibility of echocardiography strain techniques. Purpose The aim of this study was to evaluate whether CMR-FT deformation parameters play a role predicting worse clinical evolution in patients with chronic significant aortic regurgitation (AR) not meeting guidelines intervention criteria. Methods We included 85 patients with significant AR (moderate, moderate/severe, and severe) referred for CMR. Only asymptomatic patients with preserved left ventricle ejection fraction (LVEF) were considered for inclusion. Other concomitant myocardiopathies were excluded. Conventional functional left chambers parameters as well as myocardial deformation were evaluated, including global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS). A composite clinical major outcome was assessed, including admission heart failure admission, need for aortic valvule replacement and all-cause mortality. Results The mean age of the sample was 62 years old. One third of the patients were females. Other clinical baseline characteristics were not significantly different between groups when compared with Chi-squared and T-test statistical analysis. Mean follow-up was 42 months (±31). 21 patients presented with the composited outcome previously described. End-diastolic and end-systolic volumes did not differ between groups. Mean end-diastolic volume (EDV) was 196 ± 6.1 mL and mean end-systolic volume (ESV) was 88 ± 3.4 mL. Mean values of CMR-FT GLS, GCS and GRS were -14.1%, 22.8% and -16.9% respectively. GCS was selected as the best predictor for the combined endpoint point, with and area under the ROC curve of 0.67. A GCS value &amp;lt;-17% was selected as the optimal cut-off point. This value predicted events as is shown in Kaplan-Meier curves (HR 3.6, CI 95% 1.42 - 9.02, p = 0.007). A multivariate analysis showed that this association was independent of left ventricle (LV) ejection fraction, LV volumes and left atrial (LA) volume. Conclusion CMR-FT deformation parameters are impaired in significant AR patients even if intervention criteria are not met. A value of GCS &amp;lt; -17% in this population could predict a worse clinical evolution and emerges as a promising new tool helping clinical decision making in this challenging population.Kaplan-Meier curve free-event survival

Additive effect of metabolic dysfunction-associated fatty liver disease on left ventricular function and global strain in type 2 diabetes mellitus patients: a 3.0 T CMR feature tracking study

Abstract Purpose Type 2 diabetes mellitus (T2DM) represents the most prevalent form of diabetes, exerting a significant influence on cardiovascular health. Concurrently, metabolic dysfunction-associated fatty liver disease (MAFLD) is closely linked to heightened cardiac dysfunction risk. Our study aimed to explore the additive effect of MAFLD on left ventricular (LV) deformation among T2DM patients, utilizing cardiac magnetic resonance (CMR) feature tracking technology. Methods This study retrospectively included 270 patients with T2DM, comprising 110 individuals with MAFLD and 160 without, alongside 80 age- and sex-matched healthy controls, all of whom underwent CMR examination. Parameters derived from CMR encompass those related to LV function and global strain metrics. LV global strain parameters include global radial peak strain (GRPS), longitudinal peak strain (GLPS), and circumferential peak strain (GCPS), peak systolic strain rate (PSSR), and peak diastolic strain rate (PDSR), measured across radial, circumferential, and longitudinal directions. Intergroup analysis, employing the Mann-Whitney U test, was utilized to compare LV function and global strain parameters. Results The LV function parameters, including LV end-diastolic volume (LVEDV), LVEDV index, LV end-systolic volume (LVESV), LVESVI, LV mass, and LV mass index, displayed a progressive augmentation from controls through T2DM patients without MAFLD, to those with MAFLD. In parallel, LVEF showed a declining trajectory across these groups. In contrast, LVSV and LVSVI were comparable among the three groups. In a similar vein, when examining global strain parameters derived from CMR, a significant and progressive deterioration is observed across the groups. GRPS, GCPS and GLPS, along with PSSR and PDSR in radial, circumferential, and longitudinal directions, manifest a pronounced decline moving from control subjects to T2DM patients without MAFLD, and further deteriorating in those with T2DM and MAFLD (All p-values &amp;lt; 0.05). To assess the effect of MAFLD severity on global peak strain, patients with T2DM and MAFLD were stratified into two groups: a mild MAFLD group (N=77) and a moderate to severe MAFLD group (N=33). Although there was a noticeable decline in GRPS, GCPS and GLPS, as well as in PSSR and PDSR across the three groups—from those without MAFLD to those with mild and then moderate to severe MAFLD—the observed differences did not reach statistical significance. The absence of statistical significance is likely due to the small sample sizes of the groups categorized by severity of MAFLD. Conclusions This study revealed that MAFLD has additive worsening effects on LV function and LV global strains in T2DM patients evaluated by CMR. Besides, moderate to severe MAFLD, compared to mild MAFLD, exhibits worse global strain parameters. Early detection and intervention of MAFLD might improve the prognosis of T2DM patients.

Impaired strain in diabetic patients with stable coronary artery disease assessed by cardiac magnetic resonance

Abstract Background Type 2 diabetes mellitus (T2DM) can contribute or lead to myocardial structural derangement by multiple mechanisms, including ischemic cardiomyopathy and, more rarely and of difficult evaluation, diabetic cardiomyopathy. Early stages of myocardial dysfunction can be assessed by strain analysis with cardiac magnetic resonance feature tracking (CMR-FT), however, there is no studies that examined deformation parameters in diabetic patients with stablished coronary artery disease (CAD). Purpose We sought to compare the strain parameters of patients with and without T2DM with stable CAD. Methods Patients with stable multivessel CAD and preserved left ventricular ejection fraction (LVEF), included in the MASS V trial, underwent contrast-enhanced cardiac magnetic resonance before revascularization procedures. Patients were stratified according to T2DM diagnosis at baseline. Feature tracking was performed using short-axis cine images and 2- and 4-chamber long-axis images. The left ventricular endocardial and epicardial contours of the end diastole phase were manually delineated in all images. Automatically tracking contours were performed to calculate left ventricular global longitudinal (LVGLS), circumferential (LVGCS) and radial (LVGRS) strain (FIGURE 1). Results Of 202 patients studied, 88 (44%) were diabetic and 114 (56%) non-diabetic. Baseline characteristics were similar between groups (age 70 ± 10 vs 69 ± 11; 69% vs 68% males; LVEF 65 ± 13 vs 67 ± 9). Mean Syntax score was 21.2 ± 8.5 vs 20.4 ± 8.5 (P=0.52) in diabetic and non-diabetic, respectively. There were no differences in left ventricle volumes, mass and LVEF. Mean LGE mass was 2.3 ± 0.9 vs 1.9 ± 0.9 grams (P=0.32) respectively in T2DM and control groups. Strain values were all reduced in T2DM patients, as shown in FIGURE 2 (LVGLS: -15.5% ± 2.3% vs -17.5% ± 2.7%, P=0.02; LVGCS: -15.4% ± 2.6% vs -17.4% ± 3.0%, P=0.03; LVGCS: 25.9% ± 5.9% vs 29.5% ± 7.2%, P=0.01). Multivariable analyses adjusted for age, sex, BMI, hypertension, Syntax score and LGE mass showed no differences in the results. Conclusion In this study, T2DM was associated with impaired deformation parameters (decreased left ventricular global longitudinal, circumferential, and radial strain). These findings suggest myocardial dysfunction in diabetic patients when compared to control subjects in the setting of stable multivessel CAD.FIGURE 1FIGURE 2

Iron chelation therapy failed to improve cardiac dysfunction caused by mitochondrial injury in rats with iron overload cardiomyopathy a 7T Cardiac MR research in vivo

Abstract Purpose To assess the efficacy of iron chelation therapy in improving cardiac function in iron overload cardiomyopathy (IOC) rats by using Cardiac magnetic resonance feature-tracking (CMR-FT). Methods The IOC rat model was induced by intraperitoneal injection of iron dextran over 2 months. Subsequently, 7 rats with IOC were assigned as IOC group to receive continued intraperitoneal injections of saline for an additional 2 months, while another group of 5 rats received intraperitoneal injections of deferoxamine (DFO) for the same duration, forming the IOC+DFO group. Meanwhile, a control group consisting of 7 healthy rats received intraperitoneal injections of saline for the entire duration of 4 months. All rats underwent a 7T CMR scan to assess cardiac function, myocardial iron overload, and myocardial fibrosis via cine, T2 mapping, and late gadolinium enhancement (LGE) scanning, respectively. The cardiac function analysis included left ventricular ejection fraction (LVEF) and left ventricular global longitudinal strain (GLS) using cine images. Following CMR scans, all rats underwent open-chest blood collection to detect serum iron levels, and cardiac gross specimens were then subjected to pathological staining, including hematoxylin and eosin (HE) for cardiomyocytes injury, Prussian blue for iron deposition , and Masson staining for myocardial fibrosis. Furthermore, the ultrastructure of cardiomyocyte was examined using transmission electron microscopy (TEM). Results The T2 value, measured in the septum wall at the mid-layer of the LV, and LVEF, and GLS exhibited a significant decrease in the IOC or IOC+DFO group, compared to the control group, while there were no significant difference observed between the IOC and IOC+DFO group (Fig. 1A, B, C). Myocardial fibrosis was not detected in the LGE images in both IOC and IOC+DFO group. Compared to the control group (37.5±12.5μmol/L) , serum iron levels were significantly elevated in the IOC group (368.6±181.0μmol/L) and in chelation treatment group (106.1±32.2μmol/L). Histological examination with HE staining revealed a normal arrangement of myocardial cells in all rats, without cellular degeneration or necrosis. Prussian blue staining highlighted the presence of iron particles within the myocardial interstitium in the IOC and IOC+DFO groups. Masson staining demonstrated intact myocardial muscle bundles without any evidence of myocardial fibrosis. Transmission electron microscopy (TEM) revealed myocardial mitochondria injury, characterized by ruptured outer membranes, reduced cristae, and vacuolization. Conclusions Following iron chelation therapy, the excessive iron burden in the bloodstream was alleviated. However, myocardial iron overload persisted in IOC rats, with no significant improvement in cardiac function observed. This persistence may be attributed to mitochondrial injury. The findings underscore the importance of monitoring cardiac dysfunction in patients with iron overload.CMR parameters analysis in IOC rats

Assessment of left atrial function and left atrioventricular coupling via cardiac magnetic resonance in individuals with prediabetes and diabetes.

Assessment of left atrial (LA) function and the left atrioventricular coupling index (LACI) have recently been increasingly recognized as important indices for cardiovascular diseases associated with the presence of prediabetes and diabetes. We aimed to evaluate LA function and the LACI in patients with prediabetes and diabetes via cardiac magnetic resonance (CMR). In this retrospective study, we included 35 patients with prediabetes, 32 patients with diabetes, and 84 healthy control participants. The LACI and LA total, passive, and active emptying fractions (LATEmF, LAPEmF, and LAAEmF, respectively) were calculated. The LA reservoir, conduit, and booster pump strains (εs, εe, and εa), and peak positive, peak early negative, and peak late negative strain rates (SRs, SRe, and SRa) were obtained via CMR-feature tracking (CMR-FT). For the statistical analyses, one-way analysis of variance, the Kruskal-Wallis test, and linear regression were conducted, and Pearson's and interclass correlation coefficients were calculated. Compared with healthy control participants, patients with prediabetes or diabetes presented lower εs and εe values and a relatively preserved LACI. Patients with diabetes presented considerably reduced SRs, SRe, and LAPEmF. Elevated glycated haemoglobin (HbA1c) levels were independently associated with decreased magnitudes of εs, SRs, εe, and SRe. No significant associations were found between the LACI and the HbA1c or LA deformation parameters. We observed significant correlations between LATEmF and εs, LAPEmF and εe and between LAAEmF and εa. CMR-FT provides a potential noninvasive approach for the early detection of alterations in the LA reservoir and conduit function in individuals with prediabetes and diabetes.

Myocardial strain analysis by feature tracking cardiac magnetic resonance to identify subclinical cardiac dysfunction in patients with MINOCA

BackgroundTo investigate whether feature tracking cardiac magnetic resonance (FT-CMR) can identify subclinical myocardial dysfunction in patients with myocardial infarction with non-obstructed coronary arteries (MINOCA).MethodsClinical data and CMR images of MINOCA patients (N = 46) and control individuals (N = 12) were compared. The infarct and edema volume to total myocardium, peak global longitudinal strain (GLS), global longitudinal strain rate (GLSR), peak global circumferential strain (GCS), global circumferential strain rate, peak global radial strain, and global radial strain rate were measured. Diagnostic performances of strain parameters for MINOCA were evaluated by logistic regression and receiver operating characteristics analysis.ResultsExcept smoking history, the two groups showed no significant differences in cardiovascular risk factors and traditional heart function. GLS (-14.67 ± 1.96% vs. -19.19 ± 2.05%), GLSR (-0.94 ± 0.16 S− 1 vs. -1.23 ± 0.14 S− 1) and GCS (-17.59 ± 1.81% vs. -19.22 ± 1.76%) were impaired in MINOCA patients compared with the control group. MINOCA patients with normal routine CMR showed abnormalities in GLS (-16.23 ± 1.16%) and GLSR (-1.04 ± 0.16 S− 1). GLS and GLSR were predictive for MINOCA diagnosis (P = 0.002 vs. P = 0.033). GLS correlated strongly with myocardial infarction and edema. The optimal diagnostic threshold for GLS was <-16.9% for MINOCA diagnosis (sensitivity 87.1%, specificity 92.9%); the area under the receiver operating characteristic curve was 0.968.ConclusionsMyocardial strain by FT-CMR may effectively detect early myocardial impairment with MINOCA, especially in patients with normal routine MRI.

The Sub-Pulmonary Left Ventricle in Patients with Systemic Right Ventricle, the Paradoxical Neglected Chamber: A Cardiac Magnetic Resonance Feature Tracking Study.

Background/Objective: The impact of subpulmonary left ventricle (LV) dysfunction in patients with a systemic right ventricle (SRV) is insufficiently characterized, with only a few studies suggesting its prognostic significance. Additionally, its evaluation through imaging techniques is a challenge. To assess the correlation between quantitative cardiac magnetic resonance-feature tracking (CMR-FT) data and the risk of clinical events related to the natural history of SRV failure. Methods: In this cross-sectional study, 21 patients with a diagnosis of transposition of the great arteries (TGA) and atrial switch operation (AtSO) or congenitally corrected transposition (ccTGA) were recruited. All participants underwent CMR-FT analysis. Considered clinical events included NYHA class deterioration (from I-II to III-IV), increased diuretic therapy, arrhythmias, sudden cardiac death, and hospitalizations. Results: The cohort consisted of 52.4% males (mean age: 25.4 ± 11.9 years). Eleven patients were diagnosed with ccTGA. Of the 10 patients with TGA post-AtSO, 50% had undergone Mustard repair. Clinical events occurred in 11 patients, with 47.6% experiencing hospitalizations and 28.6% developing arrhythmias. Left ventricular global longitudinal strain (LV GLS) was significantly associated with event-risk in both univariate and multivariate analyses (p = 0.011; p = 0.025). A cut-off value of LV GLS > -19.24 was proposed to stratify high-risk patients (p = 0.001). Conclusions: Our study confirms the role of subpulmonary LV function in determining outcomes of SRV patients. The assessment of LV GLS by using CMR-FT could significantly enhance clinical management during follow-up.

Progress in Cardiac Magnetic Resonance Feature Tracking for Evaluating Myocardial Strain in Type-2 Diabetes Mellitus.

The global prevalence of type-2 diabetes mellitus (T2DM) has caused harm to human health and economies. Cardiovascular disease is one main cause of T2DM mortality. Increased prevalence of diabetes and associated heart failure (HF) is common in older populations, so accurately evaluating heart-related injury and T2DM risk factors and conducting early intervention are important. Quantitative cardiovascular system imaging assessments, including functional imaging during cardiovascular disease treatment, are also important. The left-ventricular ejection fraction (LVEF) has been traditionally used to monitor cardiac function; it is often preserved or increased in early T2DM, but subclinical heart deformation and dysfunction can occur. Myocardial strains are sensitive to global and regional heart dysfunction in subclinical T2DM. Cardiac magnetic resonance feature-tracking technology (CMR-FT) can visualize and quantify strain and identify subclinical myocardial injury for early management, especially with preserved LVEF. Meanwhile, CMR-FT can be used to evaluate the multiple cardiac chambers involvement mediated by T2DM and the coexistence of complications. This review discusses CMR-FT principles, clinical applications, and research progress in the evaluation of myocardial strain in T2DM.

Assessment of CMR Feature-Tracking Age- and Sex-Dependent Right Ventricular Strain in a Healthy Caucasian Cohort.

Right ventricular (RV) strain offers crucial diagnostic insights in cardiovascular and pulmonary disorders. Nonetheless, the absence of established reference values impedes its clinical implementation. Utilizing CMR-feature tracking, age- and gender-dependent RV strains were systematically assessed in 175 heart-healthy Caucasians, 97 females, median 32.5years. RV global longitudinal strain (GLS) was greater in females than males (median -26.8% (-28.3;-24.1) vs. -24.4 ± 3.0%; p < 0.001), whereby radial and circumferential strain remained comparable. Age subgroups exhibited increased RV-GLS for group B (30-50years) (-26.0 ± 3.1% vs. -24.4 ± 3.2%; p = 0.011) and group C (> 50years) (-26.7 ± 2.3% vs. -24.4 ± 3.2%; p < 0.001) compared to group A (< 30years). High intra-class correlation coefficients (ICC) were exhibited by intrarater variability (ICC = 0.86-0.95) and moderate levels for interrater variability (ICC = 0.50-0.73). CMR-feature tracking provides a fair quantification method of age- and gender-specific normal RV strain values, demonstrating that higher RV-GLS is linked to female gender and advancing age within a healthy Caucasian cohort.

Evaluating the Clinical Utility of Left Ventricular Strains in Severe AS: A Pilot Study with Feature-Tracking Cardiac Magnetic Resonance.

Background: Aortic valve stenosis (AS) is the most common degenerative valvular heart disease, significantly impacting the outcome. Current guidelines recommend valve replacement only for symptomatic patients, but advanced cardiovascular imaging, particularly cardiac magnetic resonance (CMR), may refine these recommendations. Feature-tracking CMR (FT-CMR) effectively assesses left ventricular (LV) strain and shows promise in predicting major adverse cardiovascular events (MACEs), though data on AS are limited. This study explored the role of CMR-derived LV strain in predicting MACEs occurrence in patients with severe AS. Method: We prospectively assessed 84 patients with severe AS and 84 matched controls. Global longitudinal (GLS), circumferential (GCS), and radial strain (GRS) were evaluated using FT-CMR. A composite endpoint-cardiac death, ventricular tachyarrhythmias, and heart failure hospitalization-was analyzed over a median follow-up of 31 months. Results: GLS was considerably reduced in AS patients (-15.8% vs. -19.7%, p < 0.001) and significantly predicted MACEs (HR = 1.24, p = 0.002) after adjusting for LVEF, 6 min walk distance, native T1, and late gadolinium enhancement. This underscores GLS's unique and robust predictive capability for MACEs in severe AS patients. Kaplan-Meier curves and ROC analysis both showed that GLS had the highest predictive performance for MACEs, with an AUC of 0.857. Conclusions: GLS provided independent incremental predictive value for outcome.

Interdependence between myocardial deformation and perfusion in patients with T2DM and HFpEF: a feature-tracking and stress perfusion CMR study

BackgroundPatients with diabetes have an increased risk of developing heart failure with preserved ejection fraction (HFpEF). This study aimed to compare indices of myocardial deformation and perfusion between patients with type 2 diabetes mellitus (T2DM) with and without HFpEF and to investigate the relationship between myocardial strain and perfusion reserve.MethodsThis study included 156 patients with T2DM without obstructive coronary artery disease (CAD) and 50 healthy volunteers who underwent cardiac magnetic resonance (CMR) examination at our center. Patients with T2DM were subdivided into the T2DM–HFpEF (n = 74) and the T2DM–non-HFpEF (n = 82) groups. The parameters of left ventricular (LV) and left atrial (LA) strain as well as stress myocardial perfusion were compared. The correlation between myocardial deformation and perfusion parameters was also assessed. Mediation analyses were used to evaluate the direct and indirect effects of T2DM on LA strain.ResultsPatients with T2DM and HFpEF had reduced LV radial peak systolic strain rate (PSSR), LV circumferential peak diastolic strain rate (PDSR), LA reservoir strain, global myocardial perfusion reserve index (MPRI), and increased LA booster strain compared to patients with T2DM without HFpEF (all P < 0.05). Furthermore, LV longitudinal PSSR, LA reservoir, and LA conduit strain were notably impaired in patients with T2DM without HFpEF compared to controls (all P < 0.05), but LV torsion, LV radial PSSR, and LA booster strain compensated for these alterations (all P < 0.05). Multivariate linear regression analysis demonstrated that LA reservoir and LA booster strain were independently associated with global MPRI (β = 0.259, P < 0.001; β = − 0.326, P < 0.001, respectively). Further, the difference in LA reservoir and LA booster strain between patients with T2DM with and without HFpEF was totally mediated by global MPRI. Global stress PI, LA booster, global rest PI, and global MPRI showed high accuracy in diagnosing HFpEF among patients with T2DM (areas under the curve [AUC]: 0.803, 0.790, 0.740, 0.740, respectively).ConclusionsPatients with T2DM and HFpEF exhibited significant LV systolic and diastolic deformation, decreased LA reservoir strain, severe impairment of myocardial perfusion, and elevated LA booster strain that is a compensatory response in HFpEF. Global MPRI was identified as an independent influencing factor on LA reservoir and LA booster strain. The difference in LA reservoir and LA booster strain between patients with T2DM with and without HFpEF was totally mediated by global MPRI, suggesting a possible mechanistic link between microcirculation impairment and cardiac dysfunction in diabetes. Myocardial perfusion and LA strain may prove valuable for diagnosing and managing HFpEF in the future.