Magnetic Resonance Feature Tracking Research Articles

Regional left ventricular endocardial strains estimated from low-dose 4DCT: Comparison with cardiac magnetic resonance feature tracking.

Estimates of regional left ventricular (LV) strains provide additional information to global function parameters such as ejection fraction (EF) and global longitudinal strain (GLS) and are more sensitive in detecting abnormal regional cardiac function. The accurate and reproducible assessment of regional cardiac function has implications in the management of various cardiac diseases such as heart failure, myocardial ischemia, and dyssynchrony. To develop a method that yields highly reproducible, high-resolution estimates of regional endocardial strains from 4DCT images. A method for estimating regional LV endocardial circumferential and longitudinal ( ) strains from 4DCT was developed. Point clouds representing the LV endocardial surface were extracted for each time frame of the cardiac cycle from 4DCT images. 3D deformation fields across the cardiac cycle were obtained by registering the end diastolic point cloud to each subsequent point cloud in time across the cardiac cycle using a 3D point-set registration technique. From these deformation fields, were estimated over the entire LV endocardial surface by fitting an affine transformation with maximum likelihood estimation. The 4DCT-derived strains were compared with strains estimated in the same subjects by cardiac magnetic resonance (CMR); twenty-four subjects had CMR scans followed by 4DCT scans acquired within a few hours. Regional LV circumferential and longitudinal strains were estimated from the CMR images using a commercially available feature tracking software (cvi42). Global circumferential strain (GCS) and global longitudinal strain (GLS) were calculated as the mean of the regional strains across the entire LV for both modalities. Pearson correlation coefficients and Bland-Altman analyses were used for comparisons. Intraclass correlation coefficients (ICC) were used to assess the inter- and intraobserver reproducibility of the 4DCT-derived strains. The 4DCT-derived regional strains correlated well with the CMR-derived regional strains ( : r=0.76, p<0.001; : r=0.64, p<0.001). A very strong correlation was found between 4DCT-derived GCS and 4DCT-derived EF (r=-0.96; p<0.001). The 4DCT-derived strains were also highly reproducible, with very low inter- and intraobserver variability (intraclass correlation coefficients in the range of [0.92, 0.99]). We have developed a novel method to estimate high-resolution regional LV endocardial circumferential and longitudinal strains from 4DCT images. Except for the definition of the mitral valve and LV outflow tract planes, the method is completely user independent, thus yielding highly reproducible estimates of endocardial strain. The 4DCT-derived strains correlated well with those estimated using a commercial CMR feature tracking software. The promising results reported in this study highlight the potential utility of 4DCT in the precise assessment of regional cardiac function for the management of cardiac disease.

Prognostic Value of Left Atrial Reservoir Strain in Left Ventricular Myocardial Noncompaction: A 3.0 T Cardiac Magnetic Resonance Feature Tracking Study.

The relationship of left atrial (LA) strain to high-risk heart failure (HF) events in patients with left ventricular myocardial noncompaction (LVNC) remains to be thoroughly investigated. To evaluate the LA performance in patients with LVNC, and to investigate the prognostic value of LA phasic strain on high-risk HF events, and its influencing factors. Retrospective. A total of 95 LVNC patients (74 with LA enlargement [LAE] and 21 without LAE) and 50 healthy controls. A 3.0 T, balanced steady-state free-precession cine imaging. LA longitudinal strains were measured by cardiac MRI feature tracking technique. LA volume index (LAVI) and LA ejection fraction (LAEF) were calculated. Their intraobserver and interobserver reproducibility were evaluated. The primary outcome was high-risk HF events, a composite of first HF hospitalization, hospitalization for worsening HF and death from HF. Student's t/Mann-Whitney U, one-way analysis of variance/Kruskal-Wallis, Chi-squared, receiver operating characteristic, Kaplan-Meier, log-rank, Cox regression, Pearson and Spearman correlation and linear regression analyses were performed. The significance threshold was set at P < 0 .05. LAEF and LA longitudinal strains decreased in LVNC patients irrespective of the presence of LAE. During a median follow-up of 32.17months, high-risk HF occurred in 13 (13.68%) patients. Patients with increased LAVI, decreased LAEF and decreased LA longitudinal strain had significantly higher risks of high-risk HF events. In patients with LVNC, LA reservoir strain (εs) was independently associated with high-risk HF (hazard ratio=23.208 [95% CI: 2.993-179.967]). LV global longitudinal strain (LV GLS) (β=-1.783 [95% CI: -2.493 to -1.073]) was significantly and independently associated with εs. Intraobserver and interobserver reproducibility was excellent for LAVI, LAEF, and LA strain. In patients with LVNC, εs was an independent predictor for high-risk HF events. LV GLS was an independent determinant of εs in LVNC. 4 TECHNICAL EFFICACY: Stage 4.

Detection of early signs of right ventricular systolic impairment in unoperated Ebstein's anomaly by cardiac magnetic resonance feature tracking.

Cardiovascular magnetic resonance feature-tracking analysis (CMR-FT) provides a quantitative assessment of myocardial contraction with potential for diagnostic and prognostic ability in a wide spectrum of diseases. Ebstein's anomaly (EA) is a rare congenital heart disease characterized by apical displacement of the tricuspid valve. However, it is also considered a disorder of development affecting the global right ventricular myocardium. Aim of our study is to describe the complex contractile mechanics of the functional right ventricle (RV) in patients affected by EA through CMR-FT. Fifty surgery-free EA patients who had undergone a complete CMR protocol at our institution between January 2017 and December 2020 were selected for the retrospective study. A historical control group of twenty-five healthy subjects was also included. CMR-FT analysis was performed at a dedicated workstation by manually tracing RV endo- end epicardial borders on steady-state-free-precession (SSFP) cine images. Strain values were calculated. Apical displacement of the tricuspid valve (TV) was measured on a 4-chamber cine image from the right atrio-ventricular junction to the functional annulus of the TV. EA patients presented significantly impaired RV global radial strain (GRS) and global circumferential strain (GCS) compared to controls (P<0.0001 and P=0.0008, respectively). In a subgroup analysis, GRS was significantly compromised in patients with a severely displaced TV (>16 mm/m2) compared to milder forms (P=0.03) and to controls (P<0.0001). Among EA patients with a preserved ejection fraction, 12 (48%) vs. 6 (24%) controls had reduced both GRS and GCS. The contractile pattern of the functional RV in EA is characterised by prevalent alterations in the short-axis direction as indicated by reduced GRS and GCS. Strain values might be reduced prior to routine used functional parameters like RV ejection fraction (RVEF) and can possibly serve as an early predictor of myocardial dysfunction in EA patients.

The prognostic value of global myocardium strain by CMR-feature tracking in immune checkpoint inhibitor-associated myocarditis.

Immune checkpoint inhibitor (ICI)-associated myocarditis is a potentially fatal complication. Sparse published researches evaluated the prognostic value of cardiovascular magnetic resonance feature tracking (CMR-FT) for ICI-associated myocarditis. In the single-center retrospective study, 52 patients with ICI-associated myocarditis and CMR were included from August 2018 to July 2021. The ICI-associated myocarditis was diagnosed by using the clinical criteria of the European Society of Cardiology guidelines. Major adverse cardiovascular events (MACE) were comprised of cardiovascular death, cardiogenic shock, cardiac arrest, and complete heart block. During a median follow-up of 171 days, 14 (27%) patients developed MACE. For patients with MACE, the global circumferential strain (GCS), global radial strain (GRS), global longitudinal strain (GLS), and left ventricular ejection fraction (LVEF) were significantly worse and native T1 values and late gadolinium enhancement (LGE) extent were significantly increased, compared with patients without MACE (p < 0.05). The GLS remained the independent factor associated with a higher risk of MACE (hazard ratio (HR): 2.115; 95% confidence interval (CI): 1.379-3.246; p = 0.001) when adjusting for LVEF, LGE extent, age, sex, body mass index, steroid treatment, and prior cardiotoxic chemotherapy or radiation. After adjustment for LVEF, the GLS remained the independent risk factor associated with a higher rate of MACE among patients with a preserved LVEF (HR: 1.358; 95% CI: 1.007-1.830; p = 0.045). GLS could provide independent prognostic value over GCS, GRS, traditional CMR features, and clinical features in patients with ICI-associated myocarditis. • The global circumferential strain (GCS), global radial strain (GRS), and global longitudinal strain (GLS) by cardiovascular magnetic resonance feature tracking were significantly impaired in patients with an immune checkpoint inhibitor (ICI)-associated myocarditis. • GLS was still significantly impaired in patients with preserved left ventricular ejection fraction. • The worse GLS was an independent risk factor over GCS, GRS, traditional CMR features, and clinical features for predicting major adverse cardiovascular events in patients with ICI-associated myocarditis.

The Combination of Feature Tracking and Late Gadolinium Enhancement for Identification Between Hypertrophic Cardiomyopathy and Hypertensive Heart Disease.

BackgroundThe differentiation between hypertrophic cardiomyopathy (HCM) and hypertensive heart disease (HHD) is challenging due to similar myocardial hypertrophic phenotype. The purpose of this study is to evaluate the feasibility of cardiovascular magnetic resonance feature tracking (CMR-FT) and late gadolinium enhancement (LGE) to distinguish between HCM and HHD and the potential relationship between myocardial strain and cardiac functional parameters.MethodsOne hundred and seventy subjects (57 HCM, 45 HHD, and 68 controls) underwent 3.0 T CMR, including steady-state free precession cines and LGE images. Global and segmental (basal, mid, and apical) analyses of myocardial radial, circumferential, longitudinal strain, and left ventricular (LV) torsion, as well as global and 16 segments of LGE were assessed. The multivariate analysis was used to predict the diagnostic ability by combining comprehensive myocardial strain parameters and LGE.ResultsGlobal radial strain (GRS), global circumferential strain (GCS), and LV torsion were significantly higher in the HCM group than in the HHD group (GRS, 21.18 ± 7.52 vs. 14.56 ± 7.46%; GCS, −13.34 ± 3.52 vs. −10.11 ± 4.13%; torsion, 1.79 ± 0.69 vs. 1.23 ± 0.65 deg/cm, all P < 0.001). A similar trend was also seen in the corresponding strain rate. As for segmental strain analysis, basal radial strain (BRS), basal circumferential strain (BCS), basal longitudinal strain (BLS), mid-radial strain (MRS), and mid-circumferential strain (MCS) were higher in the HCM group than in the HHD group (all P < 0.001). The receiver operating characteristic (ROC) results showed that the area under the curve (AUC) of LGE in the mid-interventricular septum (mIVS) was the highest among global and segmental LGE analyses. On the multivariate regression analysis, a combined model of LGE (mIVS) with GRS obtained the highest AUC value, which was 0.835 with 88.89% sensitivity and 70.18% specificity, respectively. In addition, for patients with HCM, GRS, GCS, and global longitudinal strain had correlations with LV ejection fraction (LVEF), maximum interventricular septum thickness (IVST max), and left ventricular mass index (LVMi). Torsion was mildly associated with LVEF.ConclusionCMR-FT-derived myocardial strain and torsion provided valuable methods for evaluation of HCM and HHD. In addition, the combination of GRS and LGE (mIVS) achieved the highest diagnostic value.

Left atrium phasic impairments in paroxysmal atrial fibrillation patients assessed by cardiovascular magnetic resonance feature tracking

Atrial fibrillation (AF) is an abnormal and irregular heartbeat caused by uncoordinated electrical impulses in the left atrium (LA), which could induce lasting changes in the heart tissue or could be a consequence of underlying cardiac disease. This study aimed to assess the left atrial phasic function and deformation in paroxysmal AF (PAF) patients—who had not received radiofrequency ablation and had no signs of permanent AF—using the cardiovascular magnetic resonance (CMR) feature-tracking (FT) technique. Fifty subjects (27 PAF patients and 23 controls) were included and examined with CMR. Their LA volume, LA function, LA longitudinal strain (LS) and LA strain rate were assessed in the LA reservoir, conduit, and contractile phases. PAF patients exhibited higher LA volumes than controls, while their LA emptying fraction and LA LS was significantly lower in all three phases. In contrast, the corresponding emptying volumes (total, passive and active) were similar in both groups. The LA volumetric rates from CMR-derived volume curves differed significantly in PAF patients vs controls in the reservoir and contractile phases. In contrast, the equivalent LV volumetric rates were similar. This study suggests that assessing the LA phasic function could offer insight into early LA impairments for PAF patients.

Evaluation of right ventricular myocardial strain in pulmonary arterial hypertension associated with atrial septal defect by cardiac magnetic resonance feature tracking.

We aimed to research the role of right ventricular strain parameters (RVSP) quantified by cardiac magnetic resonance feature tracking (CMR-FT) in the early assessment of right ventricular (RV) function in patients with pulmonary arterial hypertension associated with atrial septal defect (PAH-ASD). From September 2017 to May 2021, we retrospectively enrolled 41 patients with PAH-ASD and 20 healthy controls. All subjects underwent CMR-FT, and right heart catheterization was conducted in patients with PAH-ASD. The relationship between RVSP and RV functional parameters was subjected to correlation analysis, and intragroup correlation coefficient (ICC) and Bland-Altman plots were used to assess the consistency. The subjects were divided into three groups: Group A (controls; n = 20), Group B (PAH-ASD, RVEF ≥ 45%; n = 14), and Group C (PAH-ASD, RVEF < 45%; n = 27). Compared with healthy controls, the RV global longitudinal strain (GLS) in Group B was significantly decreased (-19.68 ± 2.72% vs. -25.21 ± 3.6%, P < 0.05). In RVEF-preserved PAH-ASD patients (Group B), compared with patients with GLS ≤ -20%, patients with GLS > -20% also had significantly elevated right ventricular end-diastolic pressure (RVEDP) [8 (6.5-8.25) mmHg vs. 4.5 ± 1.64mmHg, P < 0.05]. RV GLS had a moderate to strong correlation with RVEF, RVESVi, RVEDVi, RVEDP, and NT-proBNP (P < 0.05). ICC and Bland-Altman plots showed good intragroup and intergroup consistency in radial, circumferential and longitudinal strains of RV. In conclusion, it is feasible to quantify RV strain in patients with PAH-ASD by CMR-FT, and GLS is valuable for the early assessment of RV dysfunction in patients with PAH-ASD.

Serial Assessment of Right Ventricular Deformation in Patients With Hypoplastic Left Heart Syndrome: A Cardiovascular Magnetic Resonance Feature Tracking Study.

BackgroundAs right ventricular dysfunction is a major cause of adverse outcome in patients with hypoplastic left heart syndrome, the aim was to assess right ventricular function and deformation after Fontan completion by performing 2‐dimensional cardiovascular magnetic resonance feature tracking in serial cardiovascular magnetic resonance studies.Methods and ResultsCardiovascular magnetic resonance examinations of 108 patients with hypoplastic left heart syndrome (female: 31) were analyzed. Short‐axis cine images were used for right ventricular volumetry. Two‐dimensional cardiovascular magnetic resonance feature tracking was performed using long‐axis and short‐axis cine images to measure myocardial global longitudinal, circumferential, and radial strain. All patients had at least 2 cardiovascular magnetic resonance examinations after Fontan completion and 41 patients had 3 examinations. Global strain values and right ventricular ejection fraction decreased from the first to the third examination with a significant decline in global longitudinal strain from the first examination to the second examination (median, first, and third quartile: −18.8%, [−20.5;−16.5] versus −16.9%, [−19.3;−14.7]) and from the first to the third examination in 41 patients (−18.6%, [−20.9;−15.7] versus −15.8%, [−18.7;−12.6]; P‐values <0.004). Right ventricular ejection fraction decreased significantly from the first to the third examination (55.4%, [49.8;59.3] versus 50.2%, [45.0;55.9]; P<0.002) and from the second to the third examination (53.8%, [47.2;58.7] versus 50.2%, [45.0;55.9]; P<0.0002).ConclusionsSerial assessment of cardiovascular magnetic resonance studies in patients with hypoplastic left heart syndrome after Fontan completion demonstrates a significant reduction in global strain values and right ventricular ejection fraction at follow‐up. The significant reduction in global longitudinal strain between the first 2 examinations with non‐significant changes in right ventricular ejection fraction suggest that global longitudinal strain measured by 2‐dimensional cardiovascular magnetic resonance feature tracking might be a superior technique for the detection of changes in myocardial function.

Left atrial appendage strain and strain rate using cardiovascular magnetic resonance feature tracking: preliminary study on feasibility and reproducibility

Over the past decade, left atrial appendage (LAA) function has been widely recognised as an important marker to predict the onset of adverse cardiovascular events.1 Its active contraction prevents thrombus formation. When it is lacking, such as in atrial fibrillation,2 the thromboembolic risk is increased markedly. The mechanical properties of the LAA may regulate haemodynamic function through modulation of left atrial pressure in conditions of volume overload and increased left atrial pressure.

Short‐Term Changes in Left and Right Ventricular Cardiac Magnetic Resonance Feature Tracking Strain Following Ferric Carboxymaltose in Patients With Heart Failure: A Substudy of the Myocardial‐IRON Trial

BackgroundThe mechanisms explaining the clinical benefits of ferric carboximaltose (FCM) in patients with heart failure, reduced or intermediate left ventricular ejection fraction, and iron deficiency remain not fully clarified. The Myocardial‐IRON trial showed short‐term cardiac magnetic resonance (CMR) changes suggesting myocardial iron repletion following administration of FCM but failed to find a significant increase in left ventricular ejection fraction in the whole sample. Conversely, the strain assessment could evaluate more specifically subtle changes in contractility. In this subanalysis, we aimed to evaluate the effect of FCM on the short‐term left and right ventricular CMR feature tracking derived strain.Methods and ResultsThis is a post hoc subanalysis of the double‐blind, placebo‐controlled, randomized clinical trial that enrolled 53 ambulatory patients with heart failure and left ventricular ejection fraction <50%, and iron deficiency [Myocardial‐IRON trial (NCT03398681)]. Three‐dimensional left and 2‐dimensional right ventricular CMR tracking strain (longitudinal, circumferential, and radial) changes were evaluated before, 7 and 30 days after randomization using linear mixed‐effect analysis. The median (interquartile range) age of the sample was 73 years (65–78), and 40 (75.5%) were men. At baseline, there were no significant differences in CMR feature tracking strain parameters across both treatment arms. At 7 days, the only global 3‐dimensional left ventricular circumferential strain was significantly higher in the FCM treatment‐arm (difference: −1.6%, P=0.001). At 30 days, and compared with placebo, global 3‐dimensional left ventricular strain parameters significantly improved in those allocated to FCM treatment‐arm [longitudinal (difference: −2.3%, P<0.001), circumferential (difference: −2.5%, P<0.001), and radial (difference: 4.2%, P=0.002)]. Likewise, significant improvements in global right ventricular strain parameters were found in the active arm at 30 days (longitudinal [difference: −3.3%, P=0.010], circumferential [difference: −4.5%, P<0.001], and radial [difference: 4.5%, P=0.027]).ConclusionsIn patients with stable heart failure, left ventricular ejection fraction <50%, and iron deficiency, treatment with FCM was associated with short‐term improvements in left and right ventricular function assessed by CMR feature tracking derived strain parameters.RegistrationURL: https://www.clinicaltrials.gov; Unique identifier: NCT03398681.

Left atrial dysfunction may precede left atrial enlargement and abnormal left ventricular longitudinal function: a cardiac MR feature tracking study

BackgroundThe role of the dysfunction of left atrium in the occurrence and development of cardiovascular disease has been gradually recognized. We aim to compare the impact on left atrial (LA) function between patients with hypertrophic cardiomyopathy (HCM) and hypertension (HTN) without LA enlargement using cardiovascular magnetic resonance feature tracking (CMR-FT), and if possible, explore the capability of LA function for providing clinical implication and predicting clinical adverse events in the early stage of cardiovascular disease.MethodsConsecutive 60 HCM patients and 60 HTN patients with normal LA size among 1413 patients who underwent CMR were retrospectively analyzed as well as 60 controls. Left atrial and ventricular functions were quantified by volumetric and CMR-FT derived strain analysis from long and short left ventricular view cines. The primary endpoint was a composite of all-cause death, stroke, new-onset or worsening heart failure to hospitalization, and paroxysmal or persistent atrial fibrillation.ResultsCompared to the controls, both HTN and HCM participants had impaired LA reservoir function (εs) and conduit function (εe) with the different stage of LA booster pump dysfunction (εa). LA strain was more sensitive than LV longitudinal strain (GLS) for evaluate primary endpoint (εs: 33.9% ± 7.5 vs. 41.2% ± 14.3, p = 0.02; εe: 13.6% ± 6.2 vs. 17.4% ± 10.4, p = 0.03; εa: 20.2% ± 6.0 vs. 23.7% ± 8.8, p = 0.07; GLS: -19.4% ± 6.4 vs. -20.0% ± 6.8, p = 0.70, respectively). After a mean follow-up of 6.8 years, 23 patients reached primary endpoint. Cox regression analyses indicated impaired LA reservoir and booster pump strain were associated with clinical outcomes in patients at the early stage of HTN and HCM (p < 0.05).ConclusionsCMR-FT-derived strain is a potential and robust tool in demonstrating impaired LA mechanics, quantifying LA dynamics and underlining the impacts on LA-LV coupling in patients with HTN and HCM without LA enlargement. The corresponding LA dysfunction is a promising metric to assess clinical implication and predict prognosis at the early stage, superior to GLS.

Left Ventricular Strain Is Associated With Myocardial Recovery Following ST-Elevation Myocardial Infarction, a Prospective Longitudinal CMR Study.

BackgroundInfarct size following ST-elevation myocardial infarction (STEMI) is an important determinate of left ventricular (LV) dysfunction and cardiovascular morbidity and mortality. Cardiac magnetic resonance feature tracking (CMR-FT) is a technique that allows for the assessment of myocardial function via quantification of longitudinal, radial, and circumferential strain. We investigated the association between CMR-FT-derived myocardial global strain and myocardial recovery.MethodsA prospective study on patients presenting with STEMI treated with primary percutaneous coronary intervention (PCI) was conducted. CMR imaging was obtained at two interval time points, the baseline within 2 weeks of hospital discharge and follow-up at 6 months. Strain analysis was performed via FT-CMR, and recovery was quantified by the area of late gadolinium enhancement (LGE).ResultsA total of n = 14 patients met inclusion and exclusion criteria and were analyzed. There was a significant reduction in the infarct size, as measured by LGE mass percentage of the left ventricular muscle mass, between the initial and follow-up CMR (19.7%, IQR 12.2–23.9 vs. 17.1%, IQR 8.3–22.5, p = 0.04). Initial strain parameters were inversely correlated with the initial edema mass and the decrease in LGE mass between the initial and follow-up CMR. All LV global strains had high accuracy for the prediction of a reduction in LGE mass by 50% or more.ConclusionsLV global strains measured after primary PCI can predict the extent of myocardial recovery.

Reduced myocardial septal function assessed by cardiac magnetic resonance feature tracking in patients with hypertrophic obstructive cardiomyopathy: associated with histological myocardial fibrosis and ventricular arrhythmias.

Echocardiographic studies suggest that strain is related to myocardial fibrosis (MF) and ventricular arrhythmias (VA) in hypertrophic cardiomyopathy (HCM) patients. Cardiac magnetic resonance feature tracking (CMR-FT) also allows strain analysis, but little is known whether it provides incremental value to late gadolinium enhancement imaging (LGE). This study aimed to explore the relationship between CMR-FT-derived strain parameters and histopathology MF and VA and its incremental value to LGE in obstructive HCM (HOCM) patients undergoing septal myectomy. One hundred and twenty-three symptomatic HOCM patients underwent CMR examination, followed by septal myectomy. The abnormally increased histological MF was defined as higher than the mean + 2 standard deviation (SD) of nine control autopsy subjects who had no history of cardiovascular disease. Septal strain parameters and septal LGE were evaluated at the site of surgical myectomy. Among HOCM patients without LGE, septal circumferential (P = 0.003), longitudinal (P = 0.001), and radial (P = 0.02) strains were significantly impaired in patients with increased histological MF than those without. Histological MF was significantly associated with septal circumferential strain (r = 0.32, P < 0.001), septal longitudinal strain (r = 0.42, P < 0.001), and septal radial strain (r = -0.27, P = 0.003). On multivariate analysis, septal longitudinal strain was independently associated with histological MF [β, 0.19 (0.05-0.34); P = 0.01], and VA [odds ratio, 1.10 (1.01-1.19); P = 0.02]. Moreover, septal longitudinal strain was incremental to septal %LGE in detecting increased MF (P = 0.001) and VA (P = 0.048). Septal longitudinal strain at CMR is independently related to histological MF and occurrence of VA in HOCM patients. Moreover, it provides incremental value over LGE in detecting increased MF and VA.

Multimodality imaging in the evaluation of left ventricle myocardial deformation determined by edema and scar in acute myocarditis

Abstract Funding Acknowledgements Type of funding sources: None. INTRODUCTION acute myocarditis (aMY) is characterized by the presence of edema and myocardial scar detected by cardiovascular magnetic resonance (CMR). Aim of our study is to investigate the diagnostic value of two-dimensional (2D) speckle tracking echocardiography and Cardiovascular Magnetic Resonance (CMR) feature tracking (FT) in detecting edema and myocardial scar in aMY. METHODS all consecutive patients with clinically suspected aMY were enrolled in our study. Inclusion criteria were: 1) new ECG abnormalities 2) myocardial cytolysis markers and 3) absence of angiographically detectable coronary artery disease. Exclusion criteria included poor cine image quality caused by respiratory motion and arrhythmia. All patients underwent transthoracic echocardiography and cardiac function was evaluated by a comprehensive assessment of LV function, including 2D speckle-tracking echocardiography (2D STE). CMR was performed in all patients in a 3T scanner. Extension of edema and myocardial scar were respectively evaluated on T2 mapping and on Late Gadolinium Enhancement sequences considering numbers of segments involved according to 17-segment model (AHA). FT analysis of the left ventricle (LV) was performed using the Tissue Tracking Module to obtain LV strain data. RESULTS 52 patients were included in the study, mean age was 36± 17 years, three patients were female (6%). Mean LVEF was 56,2 ± 7,2 % and mean end diastolic volume index (EDVi) was 62,52 ± 19,02 ml/m2. 10 patients (19,2%) had impaired EF with mean values of 44,6 ± 6,15%. aMY was confirmed in all patients with the presence of myocardial edema and subepicardial late gadolinium enhancement (LGE). Inferior segments were involved in 28 patients (53,8%), lateral segment in 19 patients (36,5%), septal segments in 7 patients (13,5%) and anterior segments in 15 patients (28,8%). 2D STE LV GLS was -16.41± 5,47% while CMR-FT LV GLS was -19,07 ± 4,65%, showing a good agreement between the two methods (r = 0,5; p &amp;lt; 0,001). The univariate analysis showed a significant correlation between 2D STE LV GLS and CMR-FT LV GLS with the extension of myocardial edema assessed by CMR (r= 0,43; p= 0,002 and r = 0.47; p = 0,002 respectively). The univariate analysis did not show a significant correlation between 2D STE LV and the extension of myocardial scar assessed by CMR (r= 0.2; p= 0.155) while a significant correlation was found between CMR-FT LV GLS and myocardial scar (r = 0.4; p = 0.01). CONCLUSIONS in patients with aMY, good correlation was found between CMR-FT and 2D STE in the evaluation of GLS. 2D STE LV GLS and CMR-FT LV GLS proved to have a good correlation with the extension of myocardial edema, while only CMR-FT LV GLS proved to be associated with myocardial scar extension.

Right-ventricular involvement in acute myocarditis assessed by cardiac magnetic resonance feature tracking

Abstract Funding Acknowledgements Type of funding sources: None. INTRODUCTION the prevalence of right ventricular (RV) involvement in acute myocarditis (aMY) has been poorly investigated. Actually, RV evaluation may be difficult in echocardiography and scar detection as well as the presence of edema in cardiovascular magnetic resonance (CMR) may be challenging due to small RV wall thickness. We sought to examine the incremental diagnostic value of CMR feature tracking (FT) in RV strain-analysis for patients with aMY. METHODS all consecutive patients with clinically suspected aMY were enrolled in our study. Inclusion criteria were: 1) new ECG abnormalities 2) myocardial cytolysis markers and 3) absence of angiographically detectable coronary artery disease. Exclusion criteria included poor cine image quality caused by respiratory motion and arrhythmias. All patients underwent transthoracic echocardiography (TTE) and CMR within hospitalization on a 3T scan. CMR protocol included current standard Lake Louise criteria (LLC) for myocarditis and T2 weighted images. The definite diagnosis was made when 2 or more Lake Louise criteria were fulfilled. FT analysis of the left ventricle (LV) and RV was performed using the Tissue Tracking Module to obtain LV and RV global longitudinal (RV-GLS) strain data. 20 sex and aged matched individuals who underwent to CMR for suspected cardiac disease, which was not confirmed thereafter, were considered as control population. RESULTS 52 patients were included in the study, mean age was 36 ± 17 years, three patients were female (6%). Mean LV ejection fraction (EF) was 56,2 ± 7,2 and mean end-diastolic volume indexed (EDVi) was 62,52 ± 19,02 ml/mq. 10 patients (19%) had impaired EF with mean values of 44,6 ± 6,1%. All patients have normal RV function evaluated in TTE considering tricuspid annular plane systolic excursion (TAPSE) (22,7 ± 2,4mm). No kinetic abnormalities were reported. All patients underwent CMR within 3 ± 1 days. Normal RV-EF, normal volumes and no RV kinetic abnormalities were reported in all cases also in CMR examination. aMY was confirmed in all patients with the presence of myocardial oedema and subepicardial late gadolinium enhancement (LGE). Inferior segments were involved in 28 patients (54%), lateral segments in 19 patients (37%), septal segments in 7 patients (13%) and anterior segments in 15 patients (29%). RV-GLS was -21,5 ± 5,6% which was not significantly different from control population (-23,01 ± 3,63; p value= 0,201). Globally, 34 patients (65%) had an aMY involving inferior and lateral segments. In this subgroup, RV-GLS was significantly lower compared to other aMY (-19,8 ± 5,7 vs -23,9 ± 4,6 p value = 0,047) and compared to control population (-19,8 ± 5,7 vs -23,01 ± 3,6 p value= 0,032). CONCLUSIONS Despite normal RV function detected in both TTE and CMR, patients with infero-lateral aMY have lower values of RV longitudinal strain. CMR-FT RV strain analysis has proven to be a useful tool in detecting subclinical RV involvement in patients with aMY. Abstract Figure. CMR Right Ventricle GLS

Left atrial remodeling and the prognostic value of feature tracking derived left atrial strain in patients with light-chain amyloidosis: a cardiovascular magnetic resonance study.

Systemic light-chain (AL) amyloidosis is characterized by the aggregation of misfolded immunoglobulin light chain, predominantly infiltrating in the heart, including left atrium (LA). LA remodeling, such as increased interatrial septal thickness and enlarged size, has been observed. However, LA strain assessed by cardiac magnetic resonance feature tracking (CMR-FT) and its prognostic role remains to be further determined. Using CMR, the current study sought to investigate the characteristic of LA remodeling and the prognostic value of LA strain in patients with AL. Eighty-seven consecutive patients who underwent CMR with histologically confirmed systemic light-chain amyloidosis were retrospectively enrolled. LA strain parameters were analyzed based on CMR-FT algorithm. Amyloid infiltration and burden loads were assessed with CMR late gadolinium enhancement (LGE) and extracellular volume (ECV). Patients were categorized according to the extent of amyloid infiltration in cardiac myocardium. The primary endpoint was defined as all-cause mortality. The prognosis value of LA strain indices was evaluated using Cox proportional hazards regression and Kaplan-Meier curves. Interatrial septal thickness (3 [2-5] vs. 4 [3-5] mm, p = 0.007) and indexed LA volume (34.6 [26.9-44.6] vs. 50.5 [36.1-58.5] ml/m2, p = 0.001) were significantly higher in patients with atrial involvement (LA-LGE). Compared with patients with low amyloid burden loads (ECV group I), those at moderate and high (ECV group II and III) show progressive impairment in LA reservoir, conduit, and booster strains and strain rates. A total of 44 patients died during a median follow-up of 12months. In multivariate analysis, LA reservoir strain, New York Heart Association (NYHA), and ECV remained independently associated with survival. On Kaplan-Meier analyses, low LA reservoir strain (< 8.6%) increased the risk of mortality. In moderate amyloid burden loads patients, low LA reservoir strain provides additive prognosis value. Progress left atrial remodeling and dysfunction are common findings in AL cardiac amyloidosis. The CMR-FT-derived LA reservoir strain provides independent and additive prognostic value for all-cause mortality in patients with AL cardiac amyloidosis.

Impact of apical and mid-ventricular transmural infarcts in patients with acute myocardial infarction determined by using late gadolinium enhancement combined with feature tracking magnetic resonance.

To analyze the relationship between left ventricular (LV) myocardial strain and transmurality of myocardial infarction at three circular sections (basal, mid-ventricular, apical) by a combined analysis of cardiac magnetic resonance feature tracking (CMR-FT) and late gadolinium enhancement (LGE) information in a cohort of ST-elevation acute myocardial infarction (STEMI) patients after primary percutaneous coronary intervention (PPCI). In all, 136 patients with STEMI who underwent PPCI within 12 hours of symptom onset were included. CMR-FT and LGE-MRI were performed 5±2 days after PCI for measuring regional and global myocardial strain indexes and transmural extent. Multivariate regression analysis and Kaplan-Meier survival analysis were performed. Regional radial and circumferential strain decreased with increasing transmurality of myocardial infarction irrespective of basal, mid-ventricular, or apical segments. Segmental longitudinal strain was significantly decreased in the transmural infarcted segments only at the apical and mid-ventricular levels. A significant correlation was found between the number of transmural infarcts and global strain parameters in the apical and mid-ventricular portions. Transmural infarcted segments in apical + mid-ventricular portions >2 was related to an increased risk of cardiac events in patients with STEMI following PPCI than those ≤2. GLS was found to be an independent predictor of cardiac events in these patients. The number of transmural infarcted segments in apical + mid-ventricular portions affects LV global function and prognosis. Global longitudinal strain (GLS) is a significant predictor of adverse events after PPCI for STEMI. Morphologic and functional data fused to study complex pathophysiologic processes of LV early after STEMI may help in risk stratification of patients.

Preliminary study on the diagnostic value of cardiac magnetic resonance feature tracking for malignant ventricular arrhythmias in non-ischemic dilated cardiomyopathy.

BackgroundPatients with nonischemic dilated cardiomyopathy (NIDCM) and malignant ventricular arrhythmia (MVA) often have a poor prognosis and a high risk of sudden cardiac death. Although the diagnosis of MVA is straightforward by electrocardiogram (ECG), the underlying abnormalities of ventricular mechanics in these patients are unknown. This study aims to preliminarily explore the value of cardiac magnetic resonance feature tracking (CMR-FT) for MVA in dilated cardiomyopathy.MethodsIn this retrospective study, patients with NIDCM who met inclusion criteria were divided into an MVA group and a non-MVA group (included from January 2018 to September 2021). The interobserver agreement of myocardial strain parameters, including global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS), were tested. The GLS, GCS, GRS, left ventricular ejection fraction (LVEF), Tpeak-Tend interval on ECG and brain natriuretic peptide (BNP) were compared between groups. Single-factor and multifactor receiver operating characteristic (ROC) curve analyses were conducted to calculate the area under the ROC curve (AUC), cut-off point, sensitivity, and specificity of these parameters in predicting MVA in NIDCM.ResultsA total of 161 NIDCM patients were included (54 in the MVA group). GLS, GCS, and GRS had good interobserver agreement (all intraclass correlation coefficients >0.80). The absolute GLS and GCS, GRS and LVEF were lower in the MVA group than the non-MVA group (P<0.001), Tpeak-Tend and BNP were higher (P<0.001). Single-factor ROC curve analysis showed that GLS, GCS and GRS had certain diagnostic value for MVA (AUC =0.795, 0.802, and 0.754, respectively). Among them, GCS had higher sensitivity and specificity (GCS 0.796/0.776, GLS 0.778/0.757, GRS 0.741/0.692). Multifactor ROC curve analysis showed the combination of GLS and GCS (AUC =0.810), the combination of GCS and GRS (AUC =0.802), the combination of GLS and GRS (AUC =0.787), the combination of GLS, GCS, and GRS (AUC =0.810).ConclusionsThe three-dimensional myocardial strain parameters (especially GLS and GCS) measured by CMR-FT had certain diagnostic value and could reflect the underlying abnormality of ventricular mechanics of NIDCM with MVA.

Myocardial Deformation in the Pediatric Age Group: Normal Values for Strain and Strain Rate Using 2D Magnetic Resonance Feature Tracking.

Myocardial deformation can be assessed from routine cardiac magnetic resonance (MR) images using two-dimensional feature tracking (2D-FT). Although reference values are essential for implementation of strain imaging in clinical practice, data for the healthy pediatric age group are limited. To provide pediatric MR reference values for strain and strain rate for all four heart chambers. Retrospective. One hundred and fifty-seven healthy children from two institutions (102 male, age 4.7-18 years). 1.5 T; balanced steady-state free precession sequence. Left ventricular (LV) global and regional longitudinal, circumferential, and radial strain and strain rate as well as right ventricular (RV) and atrial global and regional longitudinal strain and strain rate were measured in two-, three-, and four-chamber views and the short axis stack. The relationships between strain parameters and age, height, weight, and gender were investigated. Age- and height-specific centile curves and tables were created for LV strain and strain rate. For all other global strain parameters, the mean was calculated as a reference. Lambda-mu-sigma (LMS)-method of Cole and Green, univariable, and multivariable linear regression models. A P value <0.05 was considered to be statistically significant. Age, height and weight had a significant influence on LV global strain values. These parameters also showed an influence on RV strain but only in boys (girls P=0.12) and none of the variables had a significant influence on atrial strain (P=0.19-0.49). Gender differences were only found for RV strain values. Pediatric potential reference values for myocardial deformation parameters of both ventricles and atria are provided. The values may serve as a reference in future studies and clinical practice. 3 TECHNICAL EFFICACY: Stage 5.

Left Ventricular Strain Measurements Derived from MR Feature Tracking: A Head-to-Head Comparison of a Higher Temporal Resolution Method With a Conventional Method.

Magnetic resonance feature tracking (MR-FT) is an imaging technique that quantifies both global and regional myocardial strain. Currently, conventional MR-FT provides a superior signal and contrast-to-noise ratio but has a relatively low temporal resolution. A higher temporal resolution MR-FT technique may provide improved results. To explore the impact of higher temporal resolution on left ventricular (LV) myocardial strain measurements using MR-FT. Prospective. One hundred and fifty-three participants including five healthy subjects and patients with various cardiac diseases referred to MR for cardiac assessment. 3 T, balanced steady-state free precession sequence with and without compressed sensing (temporal resolution: 10 msec and 40 msec, respectively). Conventional (40 msec) and higher (10 msec) temporal resolution data were acquired in all subjects during the same scanning session. Global circumferential strain (GCS), global longitudinal strain (GLS), and global radial strain (GRS) as well as peak systolic and diastolic strain rates (SRs) were measured by MR-FT and compared between the two temporal resolutions. We also performed subgroup analyses according to heart rates (HRs) and LV ejection fraction (LVEF). Paired t-test, Wilcoxon signed-rank test, linear regression analyses, Bland-Altman plots. A P value <0.05 was considered to be statistically significant. GCS and GRS were significantly higher in the 10-msec temporal resolution studies compared to the 40-msec temporal resolution studies (GCS: -13.00 ± 6.58% vs. -12.51 ± 5.76%; GRS: 21.97 ± 14.54% vs. 20.62 ± 12.52%). In the subgroup analyses, significantly higher GLS, GCS, and GRS values were obtained in subjects with LVEF ≥50%, and significantly higher GCS and GRS values were obtained in subjects with HRs <70 bpm when assessed with the 10-msec vs. the 40-msec temporal resolutions. All the peak systolic and diastolic SRs were significantly higher in the higher temporal resolution acquisitions. This was also true for all subgroups. Higher temporal resolution resulted in significantly higher cardiac strain and SR values using MR-FT and could be beneficial, particularly in patients with LVEF ≥50% and HR <70 bpm. 1 TECHNICAL EFFICACY: Stage 1.