Cardiac Magnetic Resonance Feature Tracking Research Articles

Dissecting Clinical and Metabolomics Associations of Left Atrial Phasic Function by Cardiac Magnetic Resonance Feature Tracking

Among community cohorts, associations between clinical and metabolite factors and complex left atrial (LA) phasic function assessed by cardiac magnetic resonance (CMR) feature tracking (FT) are unknown. Longitudinal LA strain comprising reservoir strain (εs), conduit strain (εe) and booster strain (εa) and their corresponding peak strain rates (SRs, SRe, SRa) were measured using CMR FT. Targeted mass spectrometry measured 83 circulating metabolites in serum. Sparse Principal Component Analysis was used for data reduction. Among community adults (n = 128, 41% female) (mean age: 70.5 ± 11.6 years), age was significantly associated with εs (β = −0.30, p < 0.0001), εe (β = −0.3, p < 0.0001), SRs (β = −0.02, p < 0.0001), SRe (β = 0.04, p < 0.0001) and SRe/SRa (β = −0.01, p = 0.012). In contrast, heart rate was significantly associated with εa (β = 0.1, p = 0.001) and SRa (β = −0.02, p < 0.0001). Serine was significantly associated with εs (β = 10.1, p = 0.015), SRs (β = 0.5, p = 0.033) and SRa (β = −0.9, p = 0.016). Citrulline was associated with εs (β = −4.0, p = 0.016), εa (β = −3.4, p = 0.002) and SRa (β = 0.4, p = 0.019). Valine was associated with ratio of SRe:SRa (β = −0.4, p = 0.039). Medium and long chain dicarboxyl carnitines were associated with εs (β = −0.6, p = 0.038). Phases of LA function were differentially associated with clinical and metabolite factors. Metabolite signals may be used to advance mechanistic understanding of LA disease in future studies.

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

Purpose/introductionThis study aims to evaluate the incremental diagnostic value of cardiac magnetic resonance (CMR) feature tracking (FT) derived atrial and ventricular strain-analysis in patients with acute myocarditis (myocarditis) as an additional tool to established Lake-Louise criteria (LLC). Material and methodsA total of 86 patients with clinically proven myocarditis and 30 healthy controls underwent a comprehensive CMR protocol. In addition to established LLC, FT derived strain parameters from the left (LA) and right atrium (RA) as well as the left (LV) and right ventricle (RV) were assessed. Receiver operating characteristics analysis was performed to compare diagnostic performance. ResultsPatients with myocarditis showed significantly reduced LA passive strain (LA εe: 26.3 ± 14.5 vs. 33.5 ± 10.1%, p = .007), LA peak early negative strain rate (LA SRe: −1.94 ± 0.59 1/s vs. −1.46 ± 0.62 1/s, p < .001), LV global longitudinal strain (LV GLS: −17.2 ± 4.9% vs. −13.3 ± 6.2%, p < .001), LV midventricular circumferential strain (LV mid CS: −25.9 ± 4.7% vs. −22.0 ± 6.5%, p < .001), and an increased RV basal circumferential SR (RV basal CSR: −0.70 ± 028 vs. −0.58 ± 0.34 1/s, p = .096) compared to healthy controls. In a subgroup analysis of patients with myocarditis and preserved LV function, RV basal CSR was also significantly increased compared to healthy controls (−0.74 ± 0.27 vs. −0.57 ± 0.26 1/s; p = .035) whereas LA SRe (−1.49 ± 0.59 vs. −1.32 ± 0.74%; p = .005) was significantly reduced. In multinominal logistic regression analysis, LA SRe and RV basal CSR proved to be the best independent predictors of myocarditis with preserved LV function. Combined with LLC, strain parameters enhanced the diagnostic performance in such patients (Areas under the curve (AUC): LLC: 0.78, LLC + LV GLS + LA SRe: 0.86), whereas LA SRe was the best performing single parameter (AUC: 0.72). ConclusionCombining quantitative CMR derived atrial and ventricular strain parameters with established LLC parameters can improve the diagnostic performance in patients with suspected myocarditis, including those with preserved LV function. Further investigations should focus on LA function, which appears to be more sensitive to early functional changes than LV function.

Temporal changes within mechanical dyssynchrony and rotational mechanics in Takotsubo syndrome: A cardiovascular magnetic resonance imaging study

BackgroundThe pathophysiological significance of dyssynchrony and rotation in Takotsubo syndrome (TTS) is unknown. We aimed to define the influence of cardiovascular magnetic resonance feature tracking (CMR-FT) dyssynchrony and rotational mechanics in acute and during clinical course of TTS. MethodsThis multicenter study included 152 TTS patients undergoing CMR (mean 3 days after symptom onset). Apical, midventricular and basal short axis views were analysed in a core-laboratory. Systolic torsion, diastolic recoil and dyssynchrony expressed as circumferential and radial uniformity ratio estimates (CURE and RURE: 0 to 1; 1 = perfect synchrony) were compared to a matched control group (n = 21). Follow-up CMR (n = 20 patients; mean 62 days, SD 7.2) and general follow-up (n = 136; mean 3.3 years, SD 2.4) were performed. ResultsCURE was initially reduced compared to controls (p = 0.001) and recovered at follow-up (p < 0.001) as opposed to RURE (p = 0.116 and p = 0.179). CURE and RURE discriminated between ballooning patterns (p = 0.001 and p = 0.045). Recoil was generally impaired during the acute phase (p = 0.015), torsion only in highly dyssynchronous patients (p = 0.024). Diabetes (p = 0.007), physical triggers (p = 0.013) and malignancies (p = 0.001) predicted mortality. The latter showed a distinct association with impaired torsion (p = 0.042) and dyssynchrony (p = 0.047). Physical triggers and malignancies were related to biventricular impairment (p = 0.004 and p = 0.026), showing higher dyssynchrony (p < 0.01), greater reduction of left ventricular function (p < 0.001) and a strong trend towards increased mortality (p = 0.074). ConclusionTransient circumferential dyssynchrony and impaired rotational mechanics are distinct features of TTS with different severities according to the pattern of ballooning. Patients with malignancies and precipitating physical triggers frequently show biventricular affection, greater dyssynchrony and high mortality risk.

Biventricular dyssynchrony on cardiac magnetic resonance imaging and its correlation with myocardial deformation, ventricular function and objective exercise capacity in patients with repaired tetralogy of Fallot

BackgroundElectrical dyssynchrony and prolonged QRS duration are common in patients with repaired tetralogy of Fallot (ToF). It has been linked to increased risk of sudden cardiac death and right ventricular (RV) dysfunction. We investigated myocardial dyssynchrony using cardiac magnetic resonance imaging (CMR) and feature tracking analysis (FT) in this setting and compared it to myocardial deformation, conventional parameters of ventricular dysfunction and clinical parameters. Methods and resultsPatients underwent standardized CMR investigations as part of a nationwide study. We prospectively assessed myocardial deformation and analysed regional wall motion abnormalities of the RV and the left ventricle (LV) using CMR-FT. The main measure of dyssynchrony was the maximal time difference (wall motion delay) of the regional strain as a parameter of mechanical biventricular dyssynchrony. In addition, clinical parameters and measures of cardiopulmonary exercise capacity were available. Overall 345 patients were included. Parameters of biventricular wall motion delay correlated significantly with global FT-strain parameters (p < 0.0001 for all imaging planes assessed). Furthermore, we found a significant correlation between circumferential RV motion delay and QRS duration (p = 0.006). Higher LV and RV wall motion delay parameters were also associated with lower peak oxygen consumption (p < 0.05) and a worse LV and RV ejection fraction (p < 0.02). ConclusionsAssessment of mechanical dyssynchrony is feasible using CMR-FT in ToF patients. Parameters of mechanical dyssynchrony correlate with electrical dyssynchrony, biventricular function and objective exercise capacity in this setting. Due to the weak degree of correlation, however, the clinical significance of these findings remains to be clarified by further studies.

Cardiac deformation parameters and rotational mechanics by cardiac magnetic resonance feature tracking in pre-adolescent male soccer players.

The purpose of the study was to analyse whether prolonged and regular physical training in children leads to changes in myocardial systolic deformation and rotational mechanics. For that purpose, cardiac MRI feature tracking was performed retrospectively in 35 pre-adolescent male soccer players and 20 matched controls. There were no changes in global strain, but left ventricular twist and apical rotation were greater in soccer players, which adds to the features of paediatric athlete's heart.

Inter-vendor reproducibility of left and right ventricular cardiovascular magnetic resonance myocardial feature-tracking.

AimSince cardiovascular magnetic resonance feature-tracking (CMR-FT) has been demonstrated to be of incremental clinical merit we investigated the interchangeability of global left and right ventricular strain parameters between different CMR-FT software solutions.Material and methodsCMR-cine images of 10 patients without significant reduction in LVEF and RVEF and 10 patients with a significantly impaired systolic function were analyzed using two different types of FT-software (TomTec, Germany; QStrain, Netherlands). Global longitudinal strains (LV GLS, RV GLS), global left ventricular circumferential (GCS) and radial strains (GRS) were assessed. Differences in intra- and inter-observer variability within and between software types based on single and up to three repeated and subsequently averaged measurements were evaluated.ResultsInter-vendor agreement was highest for GCS followed by LV GLS. GRS and RV GLS showed lower inter-vendor agreement. Variability was consistently higher in healthy volunteers as compared to the patient group. Intra-vendor reproducibility was excellent for GCS, LV GLS and RV GLS, but lower for GRS. The impact of repeated measurements was most pronounced for GRS and RV GLS on an intra-vendor level.ConclusionCardiac pathology has no influence on CMR-FT reproducibility. LV GLS and GCS qualify as the most robust parameters within and between individual software types. Since both parameters can be interchangeably assessed with different software solutions they may enter the clinical arena for optimized diagnostic and prognostic evaluation of cardiovascular morbidity and mortality in various pathologies.

LEFT VENTRICULAR GLOBAL CIRCUMFERENTIAL AND LONGITUDINAL STRAIN WITH FEATURE TRACKING CARDIOVASCULAR MAGNETIC RESONANCE ASSESSMENT AFTER ST-SEGMENT ELEVATION MYOCARDIAL INFARCTION: PROGNOSTIC IMPLICATIONS

We evaluated whether left ventricular (LV) global circumferential (GCS) and longitudinal (GLS) strain with feature tracking cardiovascular magnetic resonance (CMR) are associated with prognosis in patients after acute myocardial infarction and whether they provide incremental prognostic information

Feature Tracking Cardiac MRI Reveals Abnormalities in Ventricular Function in Patients With Bicuspid Aortic Valve and Preserved Ejection Fraction.

Subclinical systolic and diastolic left ventricular (LV) dysfunction has been reported in previous echocardiographic studies on congenital bicuspid aortic valve (BAV). Patients with BAV commonly undergo evaluation with magnetic resonance imaging, and feature-tracking cardiovascular magnetic resonance (CMR-FT) is an emerging technique that assesses myocardial strain using standard cine sequences. This study investigated differences in myocardial strain between patients with BAV with preserved ejection fraction (EF) and controls using CMR-FT. Patients with isolated BAV and preserved EF, who had previously undergone CMR (n = 42; mean age, 41.2 ± 13.9) were compared with controls (n = 19; 36.6 ± 9.8; P = .2). Investigational CMR-FT strain analysis software was used to measure circumferential systolic and diastolic strain values, as well as standard LV volumetric and functional parameters. The majority of patients with BAV had mild or no valve dysfunction, and LV myocardial mass end-diastolic volume indices were similar between groups. Peak diastolic circumferential strain rate was lower in patients with BAV than in controls (0.89 ± 0.27 vs 1.21 ± 0.21 s−1, P = .003). After adjusting for covariates, only myocardial mass index was independently associated with peak circumferential systolic strain and diastolic strain rate. Feature-tracking CMR can identify abnormalities of LV strain in a clinical cohort of asymptomatic patients with BAV with preserved EF. Decreases in circumferential diastolic strain rate in patients with BAV suggest evidence of early diastolic dysfunction.

Influence of observer experience on cardiac magnetic resonance strain measurements using feature tracking and conventional tagging

AimCMR quantitative myocardial strain analysis is increasingly being utilized in clinical routine. CMR feature tracking (FT) is now considered an alternative to the reference standard for strain assessment -CMR tagging. The impact of observer experience on the validity of FT results has not yet been investigated. The aim of this study was therefore to evaluate the observer experience-dependency of CMR FT and to compare results with the reference standard. MethodsCSPAMM and SSFP-Cine sequences were acquired in 38 individuals (19 patients with HFpEF,19 controls) in identical midventricular short-axis locations. Global peak systolic circumferential strain (PSCS) together with LV ejection fraction (EF) and volumes were assessed by three observers (5,3 and 0 years of CMR-strain experience). Intermodality, intra- as well inter-observer variability were assessed. ResultsCorrelation between tagging and FT derived PSCS depended on observer experience (r = 0.69, r = 0.58 and r = 0.53). For the inexperienced observer tagging and FT derived PSCS differed significantly (p = 0.0061). Intra-observer reproducibility of tagging derived PSCS were similar for all observers (coefficient of variation (CV): 6%, 6.8% and 4.9%) while reproducibility of FT derived PSCS (CV: 7.4%, 9.4% and 15.8%) varied depending on observer experience. Inter-observer reproducibility of tagging derived PSCS for observer 1 and 2 as well as 1 and 3 for tagging (CV: 6.17%, 9.18%) was superior in comparison to FT (CV: 11.8%, 16.4%). ConclusionsReliability and accuracy of FT based strain analysis, more than tagging based strain analysis, is dependent on reader experience. CMR strain experience or dedicated training in strain evaluation is necessary for FT to deliver accurate strain data, comparable to that of CMR tagging.

STRAIN IMAGING TECHNIQUES TO PREDICT CARDIAC RESYNCHRONIZATION THERAPY RESPONSE: A HEAD-TO-HEAD COMPARISON OF CARDIAC MAGNETIC RESONANCE MYOCARDIAL TAGGING, FEATURE TRACKING AND SPECKLE TRACKING ECHOCARDIOGRAPHY

Myocardial strain imaging could potentially improve patient selection for cardiac resynchronization therapy (CRT). Available techniques are CMR tagging (CMR-TAG), feature tracking (CMR-FT) and speckle tracking echocardiography (STE). Despite promising results per modality, a direct comparison is

Atrio-ventricular deformation and heart failure in Ebstein's Anomaly — A cardiovascular magnetic resonance study

PurposeWe aimed to quantify atrial and ventricular myocardial deformation in Ebstein's Anomaly (EA) in a case-control study with cardiovascular magnetic resonance (CMR) feature tracking and to correlate changes in cardiac performance with the severity of disease and clinical heart failure parameters. Materials and methodsAtrial and ventricular deformation was measured using CMR feature tracking in 30 EA and 20 healthy control subjects. Atrial performance was characterized using longitudinal strain and strain rate parameters for reservoir function, conduit function and booster pump function. Ventricular performance was characterized using RV and LV global longitudinal strain (εl) and LV circumferential and radial strain (εc and εr). Volumetric measurements for the ventricles including the Total Right/Left-Volume-Index (R/L-Volume-Index) and heart failure markers (BNP, NYHA class) were also quantified. ResultsEA patients showed significantly impaired right atrial performance, which correlated with heart failure markers (NYHA, BNP, R/L-Volume-Index). LA function in EA patients was also impaired with atrial contractile function correlating with NYHA class. EA patients exhibited impaired RV myocardial deformation, also with a significant correlation with heart failure markers. ConclusionCMR feature tracking can be used to quantify ventricular and atrial function in a complex cardiac malformation such as EA. EA is characterized by impaired quantitative right heart atrio-ventricular deformation, which is associated with heart failure severity. While LV function remains preserved, there is also significant impairment of LA function. These quantitative performance parameters may represent early markers of cardiac deterioration of potential value in the clinical management of EA.

Impact of surgical pulmonary valve replacement on ventricular strain and synchrony in patients with repaired tetralogy of Fallot: a cardiovascular magnetic resonance feature tracking study

BackgroundIn patients with repaired tetralogy of Fallot (TOF), a better understanding of the impact of surgical pulmonary valve replacement (PVR) on ventricular mechanics may lead to improved indications and outcomes. Therefore, we used cardiovascular magnetic resonance (CMR) feature tracking analysis to quantify ventricular strain and synchrony in repaired TOF patients before and after PVR.MethodsThirty-six repaired TOF patients (median age 22.4 years) prospectively underwent CMR a mean of 4.5 ± 3.8 months before PVR surgery and 7.3 ± 2.1 months after PVR surgery. Feature tracking analysis on cine steady-state free precession images was used to measure right ventricular (RV) and left ventricular (LV) circumferential strain from short-axis views at basal, mid-ventricular, and apical levels; and longitudinal strain from 4-chamber views. Intraventricular synchrony was quantified using the maximum difference in time-to-peak strain, the standard deviation of the time-to-peak, and cross correlation delay (CCD) metrics; interventricular synchrony was assessed using the CCD metric.ResultsFollowing PVR, RV end-diastolic volume, end-systolic volume, and ejection fraction declined, and LV end-diastolic volume and end-systolic volume both increased with no significant change in the LV ejection fraction. LV global basal and apical circumferential strains, and basal synchrony improved. RV global circumferential and longitudinal strains were unchanged, and there was a varied impact on synchrony across the locations. Interventricular synchrony worsened at the midventricular level but was unchanged at the base and apex, and on 4-chamber views.ConclusionsSurgical PVR in repaired TOF patients led to improved LV global strain and no change in RV global strain. LV and RV synchrony parameters improved or were unchanged, and interventricular synchrony worsened at the midventricular level.

Myocardial tissue characterization and strain analysis in healthy pregnant women using cardiovascular magnetic resonance native T1 mapping and feature tracking technique

BackgroundPeripartum cardiomyopathy is a life-threatening condition that occurs during the peripartum period in previously healthy women. Cardiovascular magnetic resonance (CMR) T1 mapping permits sensitive detection of tissue edema and fibrosis, and it may be useful in identifying altered myocardial tissue characteristics in peripartum cardiomyopathy. However, left ventricular (LV) volumes and mass increase considerably even in normal pregnancy, and it is not known whether altered tissue characteristics can be found in normal pregnancy. The aim of this study was to investigate whether the LV remodeling observed in normal pregnancy is associated with altered tissue characteristics determined by CMR.MethodsTwelve normal pregnant women and 15 non pregnant women underwent cine CMR and myocardial T1 measurement at 1.5 T. Pregnant women were scanned three times, in the 2nd and 3rd trimesters of pregnancy and at 1 month postpartum. LV volumes, LV mass (LVM), and global longitudinal strain (GLS) were analyzed by cine CMR. Native myocardial T1 was determined using modified Look-Locker inversion recovery (MOLLI) images.ResultsLV end-diastolic volume (EDV) was significantly greater in the 3rd trimester (126 ± 22 mL) than in non-pregnant women (108 ± 14 mL, p < 0.05). LVM was significantly greater in the 3rd trimester (88.7 ± 11.8 g) than at 1 month postpartum (70.0 ± 9.8 g, p < 0.05) and in non-pregnant women (66.3 ± 13.9 g, p < 0.05). Myocardial native T1 among the 2nd and 3rd trimesters, 1 month postpartum, and non-pregnant women were similar (1133 ± 55 ms, 1138 ± 86 ms, 1105 ± 45 ms, and 1129 ± 52 ms, respectively, p = 0.59) as were GLS (− 19.5 ± 1.8, − 19.7% ± 2.2, − 19.0% ± 2.0%, and − 19.3% ± 1.9%, respectively, p = 0.66).ConclusionsLV remodeling during normal pregnancy is associated with myocardial hypertrophy, but not with edema or diffuse fibrosis of the myocardium or LV contractile dysfunction. These results observed in normal pregnancy will serve as an important basis for identifying myocardial abnormalities in patients with peripartum cardiomyopathy and other pregnancy-related myocardial diseases.

Feature-Tracking Global Longitudinal Strain Predicts Death in a Multicenter Population of Patients With Ischemic and Nonischemic Dilated Cardiomyopathy Incremental to Ejection Fraction and Late Gadolinium Enhancement

ObjectivesThe aim of this study was to evaluate the prognostic value of cardiac magnetic resonance (CMR) feature-tracking–derived global longitudinal strain (GLS) in a large multicenter population of patients with ischemic and nonischemic dilated cardiomyopathy. BackgroundDirect assessment of myocardial fiber deformation with GLS using echocardiography or CMR feature tracking has shown promise in providing prognostic information incremental to ejection fraction (EF) in single-center studies. Given the growing use of CMR for assessing persons with left ventricular (LV) dysfunction, we hypothesized that feature-tracking–derived GLS may provide independent prognostic information in a multicenter population of patients with ischemic and nonischemic dilated cardiomyopathy. MethodsConsecutive patients at 4 U.S. medical centers undergoing CMR with EF <50% and ischemic or nonischemic dilated cardiomyopathy were included in this study. Feature-tracking GLS was calculated from 3 long-axis cine-views. The primary endpoint was all-cause death. Cox proportional hazards regression modeling was used to examine the association between GLS and death. Incremental prognostic value of GLS was assessed in nested models. ResultsOf the 1,012 patients in this study, 133 died during median follow-up of 4.4 years. By Kaplan-Meier analysis, the risk of death increased significantly with worsening GLS tertiles (log-rank p < 0.0001). Each 1% worsening in GLS was associated with an 89.1% increased risk of death after adjustment for clinical and imaging risk factors including EF and late gadolinium enhancement (LGE) (hazard ratio [HR]:1.891 per %; p < 0.001). Addition of GLS in this model resulted in significant improvement in the C-statistic (0.628 to 0.867; p < 0.0001). Continuous net reclassification improvement (NRI) was 1.148 (95% confidence interval: 0.996 to 1.318). GLS was independently associated with death after adjustment for clinical and imaging risk factors (including EF and late gadolinium enhancement) in both ischemic (HR: 1.942 per %; p < 0.001) and nonischemic dilated cardiomyopathy subgroups (HR: 2.101 per %; p < 0.001). ConclusionsCMR feature-tracking–derived GLS is a powerful independent predictor of mortality in a multicenter population of patients with ischemic or nonischemic dilated cardiomyopathy, incremental to common clinical and CMR risk factors including EF and LGE.

Preserved Myocardial Deformation after Successful Coarctation Repair: A CMR Feature-Tracking Study

Arterial vasculopathy and residual aortic obstruction can lead to left ventricular (LV) dysfunction in patients with coarctation of the aorta (CoA) related to adverse ventriculo-arterial coupling. This study aimed to investigate potential differences in LV myocardial deformation indices between repaired CoA patients and healthy controls. Twenty-two CoA patients (age 30 ± 10.6 years) after surgical repair (n = 12) or balloon angioplasty (BA) (n = 10) without residual stenosis, between 3 months and 16 years of age with > 10 years follow-up were compared to 22 healthy age- and gender-matched controls (age 30 ± 3.8 years). Cardiac magnetic resonance feature tracking (CMR-FT) was used for LV longitudinal-, circumferential-, and rotational deformation indices. Global systolic LV function was preserved in CoA patients (LV ejection fraction 58 ± 4.8 vs. 60 ± 6.8%, p = 0.56) when compared to controls, with normal LV dimensions and mass (p > 0.05). Twelve CoA patients (55%) were hypertensive, of whom 4 were on anti-hypertensive medication. LV global longitudinal strain was preserved in the four-chamber (− 18 ± 4.4 vs. − 16 ± 4.7%, p = 0.06) and two-chamber (− 22 ± 5.1 vs. − 20 ± 6.0%, p = 0.22) orientations in CoA patients. Global circumferential strain was preserved at basal (− 29 ± 4.1 vs. − 28 ± 4.8%, p = 0.43), mid-ventricular (− 27 ± 4.2 vs. − 25 ± 3.0%, p = 0.09), and apical levels (− 35 ± 7.8 vs. − 32 ± 34.9%, p = 0.32). No differences were found in global torsion (2.4 ± 1.3° vs. 2.0 ± 1.4°/cm, p = 0.28), twist (14 ± 5.8° vs. 12 ± 6.3°, p = 0.34), and recoil rate (− 17 ± 9.7° vs. − 17 ± 7.1°/cm s, p = 0.97). Analysis of intra-observer variability demonstrated good reproducibility for all CMR deformation indices. Global and rotational myocardial deformation indices are preserved in CoA patients long-term after repair without residual stenosis, despite a high incidence of hypertension.

Prognostic implications of global myocardial mechanics in hypertrophic cardiomyopathy by cardiovascular magnetic resonance feature tracking. Relations to left ventricular hypertrophy and fibrosis

BackgroundInterstitial fibrosis, myocardial fiber disarray and non-uniform shortening are common histological features of hypertrophic cardiomyopathy (HCM). The degree of LV hypertrophy and fibrosis are postulated to contribute to the impairment of myocardial shortening. Cardiovascular magnetic resonance myocardial (CMR) feature tracking (CMR-FT) has emerged as a robust method that provides quantitative measurements of myocardial deformation. Our aim was first to evaluate LV strain parameters in HCM by CMR-FT and their dependence on both functional parameters and late gadolinium enhancement (LGE); and secondly we sought to determine their association with major cardiovascular outcomes. Methods and results74 patients with HCM and 75 controls subjects underwent a CMR study including LGE imaging. Global peak longitudinal, circumferential and radial systolic strain values (GLS, GCS, GRS) were measured by CMR-FT. A primary endpoint of all-cause mortality and secondary combined endpoint of hospital admission related to heart failure, lethal ventricular arrhythmias or cardiovascular death were defined. Patients with HCM showed attenuation of all LV strain values (p<0.001). Multivariate analysis showed that both LV hypertrophy and %of LGE were independent predictors of attenuated LV strains. All systolic LV strain parameters were impaired in patients with primary and secondary endpoints (follow up time: 25.6±9.9months, p<0.05 and p<0.01 respectively). Abnormal GLS, GCS and GRS were significantly associated with primary and secondary endpoints. ConclusionBoth LV hypertrophy and fibrosis contribute to the impairment of LV myocardial mechanics in HCM. In this population, reduced LV strain is associated with poor cardiac outcomes, particularly cardiovascular mortality and HF.

Normal values for myocardial deformation within the right heart measured by feature-tracking cardiovascular magnetic resonance imaging

BackgroundReproducible and repeatable assessment of right heart function is vital for monitoring congenital and acquired heart disease. There is increasing evidence for the additional value of myocardial deformation (strain and strain rate) in determining prognosis. This study aims to determine the reproducibility of deformation analyses in the right heart using cardiovascular magnetic resonance feature tracking (FT-CMR); and to establish normal ranges within an adult population.MethodsA cohort of 100 healthy subjects containing 10 males and 10 females from each decade of life between the ages of 20 and 70 without known congenital or acquired cardiovascular disease, hypertension, diabetes, dyslipidaemia or renal, hepatic, haematologic and systemic inflammatory disorders underwent FT-CMR assessment of right ventricular (RV) and right atrial (RA) myocardial strain and strain rate.ResultsRV longitudinal strain (Ell) was − 21.9 ± 3.24% (FW + S Ell) and − 24.2 ± 3.59% (FW-Ell). Peak systolic strain rate (S′) was − 1.45 ± 0.39 s− 1 (FW + S) and − 1.54 ± 0.41 s− 1 (FW). Early diastolic strain rate (E′) was 1.04 ± 0.26 s− 1 (FW + S) and 1.04 ± 0.33 s− 1 (FW). Late diastolic strain rate (A′) was 0.94 ± 0.33 s− 1 (FW + S) and 1.08 ± 0.33 s− 1 (FW). RA peak strain was − 21.1 ± 3.76%. The intra- and inter-observer ICC for RV Ell (FW + S) was 0.92 and 0.80 respectively, while for RA peak strain was 0.92 and 0.89 respectively.ConclusionsNormal values of RV & RA deformation for healthy individuals using FT-CMR are provided with good RV Ell and RA peak strain reproducibility. Strain rate suffered from sub-optimal reproducibility and may not be satisfactory for clinical use.

Comparison of strain imaging techniques in CRT candidates: CMR tagging, CMR feature tracking and speckle tracking echocardiography

Parameters using myocardial strain analysis may predict response to cardiac resynchronization therapy (CRT). As the agreement between currently available strain imaging modalities is unknown, three different modalities were compared. Twenty-seven CRT-candidates, prospectively included in the MARC study, underwent cardiac magnetic resonance (CMR) imaging and echocardiographic examination. Left ventricular (LV) circumferential strain was analysed with CMR tagging (CMR-TAG), CMR feature tracking (CMR-FT), and speckle tracking echocardiography (STE). Basic strain values and parameters of dyssynchrony and discoordination obtained with CMR-FT and STE were compared to CMR-TAG. Agreement of CMR-FT and CMR-TAG was overall fair, while agreement between STE and CMR-TAG was often poor. For both comparisons, agreement on discoordination parameters was highest, followed by dyssynchrony and basic strain parameters. For discoordination parameters, agreement on systolic stretch index was highest, with fair intra-class correlation coefficients (ICC) (CMR-FT: 0.58, STE: 0.55). ICC of septal systolic rebound stretch (SRSsept) was poor (CMR-FT: 0.41, STE: 0.30). Internal stretch factor of septal and lateral wall (ISFsep–lat) showed fair ICC values (CMR-FT: 0.53, STE: 0.46), while the ICC of the total LV (ISFLV) was fair for CMR-FT (0.55) and poor for STE (ICC: 0.32). The CURE index had a fair ICC for both comparisons (CMR-FT: 0.49, STE 0.41). Although comparison of STE to CMR-TAG was limited by methodological differences, agreement between CMR-FT and CMR-TAG was overall higher compared to STE and CMR-TAG. CMR-FT is a potential clinical alternative for CMR-TAG and STE, especially in the detection of discoordination in CRT-candidates.

Myocardial deformation assessment using cardiovascular magnetic resonance-feature tracking technique.

Cardiovascular magnetic resonance (CMR) imaging is an important modality that allows the assessment of regional myocardial function by measuring myocardial deformation parameters, such as strain and strain rate throughout the cardiac cycle. Feature tracking is a promising quantitative post-processing technique that is increasingly used. It is commonly applied to cine images, in particular steady-state free precession, acquired during routine CMR examinations. To review the studies that have used feature tracking techniques in healthy subjects or patients with cardiovascular diseases. The article emphasizes the advantages and limitations of feature tracking when applied to regional deformation parameters. The challenges of applying the techniques in clinics and potential solutions are also reviewed. Research studies in healthy volunteers and/or patients either applied CMR-feature tracking alone to assess myocardial motion or compared it with either established CMR-tagging techniques or to speckle tracking echocardiography. These studies assessed the feasibility and reliability of calculating or determining global and regional myocardial deformation strain parameters. Regional deformation parameters are reviewed and compared. Better reproducibility for global deformation was observed compared with segmental parameters. Overall, studies demonstrated that circumferential was the most reproducible deformation parameter, usually followed by longitudinal strain; in contrast, radial strain showed high variability. Although feature tracking is a promising tool, there are still discrepancies in the results obtained using different software packages. This highlights a clear need for standardization of MRI acquisition parameters and feature tracking analysis methodologies. Validation, including physical and numerical phantoms, is still required to facilitate the use of feature tracking in routine clinical practice.

Myocardial deformation assessed by longitudinal strain: Chamber specific normative data for CMR-feature tracking from the German competence network for congenital heart defects.

Left ventricular two-dimensional global longitudinal strain (LS) is superior to ejection fraction (EF) as predictor of outcome. We provide reference data for atrial and ventricular global LS during childhood and adolescence by CMR feature tracking (FT). We prospectively enrolled 115 healthy subjects (56 male, mean age 12.4 ± 4.1 years) at a single institution. CMR consisted of standard two-dimensional steady-state free-precession acquisitions. CMR-FT was performed on ventricular horizontal long-axis images for derivation of right and left atrial (RA, LA) and right and left ventricular (RV, LV) peak global LS. End-diastolic volumes (EDVs) and EF were measured. Correlations were explored for LS with age, EDV and EF of each chamber. Mean±SD of LS (%) for RA, RV, LA and LV were 26.56±10.2, -17.96±5.4, 26.45±10.6 and -17.47±5, respectively. There was a positive correlation of LS in LA, LV, RA and RV with corresponding EF (all P<0.05); correlations with age were weak. Gender-wise differences were not significant for atrial and ventricular LS, strain rate and displacement. Inter- and intra-observer comparisons showed moderate agreements. Chamber-specific nomograms for paediatric atrial and ventricular LS are provided to serve as clinical reference, and to facilitate CMR-based deformation research. • No normative data exist for CMR-derived global longitudinal strain in the young. • This prospective study provides reference data for atrial and ventricular longitudinal strain. • The data will serve as reference for CMR-based clinical and research use.