Cardiac Magnetic Resonance Feature Tracking Research Articles

Kiosk 8R-FC-02 - Left Atrial Strain Is in Part Determined by Left Ventricular Function in Heart Failure with Reduced Ejection FBaction; A Cardiac Magnetic Resonance Feature-tracking Study

Kiosk 8R-FC-02 - Left Atrial Strain Is in Part Determined by Left Ventricular Function in Heart Failure with Reduced Ejection FBaction; A Cardiac Magnetic Resonance Feature-tracking Study

Incremental Diagnostic Value of Right Ventricular Strain Analysis in Arrhythmogenic Right Ventricular Cardiomyopathy.

Strain analysis is a sensitive method for the assessment of ventricular structural or functional alterations. The authors aimed to determine whether right ventricular (RV) strain parameters can discriminate patients with revised Task Force Criteria-diagnosed arrhythmogenic RV cardiomyopathy (ARVC) incremental to the existing cardiovascular magnetic resonance (CMR) criteria, thus improving the diagnostic yield of CMR in ARVC. A total of 74 patients with revised Task Force Criteria-diagnosed ARVC (37 borderline and 37 definite) and 37 controls were retrospectively enrolled for analysis. Using CMR feature tracking, RV global longitudinal (GLS), circumferential, and radial strain of all participants were evaluated. Compared with controls, the study patients demonstrated significantly impaired global biventricular strain in all 3 directions (all P<0.001). Receiver operating characteristic curve analysis indicated that RV GLS was the strongest discriminator among all RV strain parameters for the identification of patients with ARVC (area under the curve, 0.92). Using the Youden index, the authors determined RV GLS ≥-19.95% as the diagnostic criterion of ARVC. In patients diagnosed with borderline ARVC according to revised Task Force Criteria but with no or only minor CMR criteria, there were >50% presenting with impaired RV GLS. When both conventional criteria and RV GLS were considered together, this new diagnostic method demonstrated an overall diagnostic accuracy of 90%. The likelihood ratio test showed a significant incremental diagnostic value of RV GLS (P=0.02) over the existing CMR major criteria. The current study showed an improved diagnostic accuracy when both RV GLS and the existing CMR criteria were considered together, especially for patients with borderline diagnosis, suggesting the incremental value of strain analysis to the initial assessment of ARVC.

Feature-Tracking-Derived Strain Analysis for Identification of Subendocardium-Involved Late Gadolinium Enhancement in Load-Induced Left Ventricular Hypertrophy: A Multicenter Study of Cardiac Magnetic Resonance Data.

Subendocardium-involved late gadolinium enhancement (SILGE) is a significant predictor of poor prognosis in patients with load-induced left ventricular hypertrophy (LVH). This multicenter study aimed to investigate whether the diagnostic performance of cardiac magnetic resonance feature-tracking (CMR-FT)-derived strain analysis for detecting subtle subendocardial injury would be influenced by its load dependence in patients with load-induced LVH. A total of 149 patients with load-induced LVH were recruited from three centers and underwent enhanced CMR imaging. The patients were divided into two groups based on the presence or absence of SILGE on CMR (SILGE+ group: n = 56; SILGE- group: n = 93). Clinical and CMR parameters were evaluated in both groups. The LV systolic pressure (LVSP) and LV end-diastolic pressure (LVEDP) in the SILGE+ group were higher than those in the SILGE- group (each with p < 0.05), and LVSP and LVEDP were correlated with the LV global longitudinal strain (GLS) (each with p < 0.05) in research center 1. The LV strain parameters were significantly lower in the SILGE+ group than those in the SILGE- group (each with p < 0.05). Logistic regression analysis identified GLS (OR 1.325; 95% CI 1.180 to 1.487, p < 0.001) as a predictive factor of SILGE in the patients with load-induced LVH. The receiver operating characteristic (ROC) curve analysis results indicated that the areas under the curve (AUC) of global radial strain (GRS), global circumferential strain (GCS), and GLS were 0.68, 0.69, and 0.76, respectively. De Long's test results implied that GLS had the best diagnostic performance for SILGE (p = 0.04). Despite the load dependency of CMR-FT-derived strain analysis, the GLS exhibits reasonable accuracy in the identification of SILGE and can potentially serve as a feasible alternative for detecting subendocardial involvement in patients with load-induced LVH who are contraindicated for LGE.

Direct comparison of coronary microvascular obstruction evaluation using CMR feature tracking and layer-specific speckle tracking echocardiography in STEMI patients

PurposeLayer-specific speckle tissue echocardiography (LS-STE) is a unique technique used to assess coronary microvascular obstruction (CMVO) that may offer more information on the myocardial anatomy of patients with ST-elevation myocardial infarction (STEMI). Cardiovascular magnetic resonance feature tracking (CMR-FT) has also been gaining popularity as a way to evaluate CMVO. The aim of the present study was to directly compare CMVO assessment in STEMI patients using CMR-FT and LS-STE.Patients and methodsA total of 105 STEMI patients with LS-STE, CMR-FT, and primary percutaneous coronary intervention (PPCI) were included in the study. Longitudinal peak systolic strain (LS), circumferential peak systolic strain (CS), and radial peak systolic strain (RS) were each used to evaluate CMVO using CMR-FT and LS-STE.ResultsCorrelation coefficients were 0.56, 0.53, and 0.55 for CMR-FT CS vs. endocardial CS, midcardial CS, and epicardial CS comparisons, respectively, and 0.87, 0.51, and 0.32 for CMR-FT LS vs. endocardial LS, midcardial LS, and epicardial LS comparisons, respectively. Bland-Altman analysis revealed strong inter-modality agreement and little bias in endocardial LS, while the absolute of limited of agreement (LOA) value was 2.28 ± 4.48. The absolutes LOA values were 1.26 ± 11.16, -0.02 ± 12.21, and − 1.3 ± 10.27 for endocardial, midcardial, and epicardial respectively. Intraclass correlation coefficient value of 0.87 showed good reliability in endocardial LS, and moderate reliability with values of 0.71, 0.70, and 0.64 in endocardial, midcardial, and epicardial CS, respectively (all p < 0.001).ConclusionsCMR-FT is a viable technique for CMVO evaluation in STEMI patients. Endocardial LS showed good reliability for CMR-FT. STEMI patients can undergo LS-STE to assess the CMVO before PPCI.

Lower ventricular and atrial strain in patients who recovered from COVID-19 assessed by cardiovascular magnetic resonance feature tracking.

One of the most common complications of coronavirus disease 2019 (COVID-19) is myocardial injury, and although its cause is unclear, it can alter the heart's contractility. This study aimed to characterize the ventricular and atrial strain in patients who recovered from COVID-19 using cardiovascular magnetic resonance feature-tracking (CMR-FT). In this single-center study, we assessed left ventricle (LV) and right ventricular (RV) global circumferential strain (GCS), global longitudinal strain (GLS), global radial strain (GRS), left atrial (LA) and right atrial (RA) longitudinal strain (LS) parameters by CMR-FT. The student's t-test and Wilcoxon rank-sum test were used to compare the variables. We compared seventy-two patients who recovered from COVID-19 (49 ± 16 years) to fifty-four controls (49 ± 12 years, p = 0.752). The patients received a CMR examination 48 (34 to 165) days after the COVID-19 diagnosis. 28% had LGE. Both groups had normal LV systolic function. Strain parameters were significantly lower in the COVID-19 survivors than in controls. Patients who recovered from COVID-19 exhibited significantly lower strain in the left ventricle (through LVGCS, LVGLS, LVGRS), right ventricle (through RVGLS and RVGRS), left atrium (through LALS), and right atrium (through RALS) than controls.

The impact of surgical aortic valve replacement on myocardial deformation in patients with severe aortic stenosis: a comparison between echocardiography and CMR

Abstract Background Aortic valve replacement (AVR) in patients with severe aortic stenosis (AS) leads to reverse remodelling, with reduction in left ventricle (LV) mass and volumes. However, the effect of AVR on left atrial (LA) and LV myocardial deformation using speckle tracking echocardiography (STE) and feature tracking cardiac magnetic resonance (FT-CMR) has not been extensively compared in the same cohort. Methods Patients with severe AS scheduled for AVR were recruited. Same-day TTE and CMR scans were performed pre- and post-AVR using a standard protocol. Myocardial deformation was assessed using STE and FT-CMR by a blinded single observer. LA strain (LAS) corresponding to reservoir, conduit and booster pump function were assessed on 4- and 2-chamber and average values calculated. For the LV, the three long-axis views were utilised for global longitudinal strain (GLS) and peak early diastolic strain rate (PEDSR). Mid circumferential strain (Mid-CS) and PEDSR were calculated from the mid short-axis view. Global circumferential strain (GCS) and PEDSR were derived by averaging values from the basal, mid and apical short axis cine slices by FT-CMR only. Results We recruited 78 patients with severe AS, 66 of whom (mean age 67.0±9.4 years; 75.8% males) had matched pre- and post-AVR CMR scans. Median follow-up period was 6 months. LV assessment by TTE was limited by image quality (&amp;gt;20% unanalysable images). STE demonstrated a significant increase in reservoir and conduit LAS, GLS and longitudinal PEDSR post-AVR (Table 1&amp;2). FT-CMR demonstrated a significant increase in booster-pump LAS, GLS, GCS and longitudinal/ circumferential-PEDSR post-AVR. Conclusion In patients with severe AS, significant increase in LV GLS and longitudinal-PEDSR was seen using both FT-CMR and STE. GCS and circumferential-PEDSR were significantly increased using FT-CMR only, suggesting that CMR may be more sensitive to subtle changes in LV function at 6 months post-AVR. LAS assessment showed significant improvements post-AVR by both imaging modalities.Table 1Table 2

Right ventricular global longitudinal strain on cardiovascular magnetic resonance imaging predicts outcome in patients undergoing transcatheter edge-to-edge mitral valve repair

Abstract Background Right ventricular dysfunction (RVD) on echocardiography was shown to predict outcomes in patients undergoing transcatheter edge-to-edge mitral valve repair (M-TEER). However, the prognostic value of left and RV global longitudinal strain (LV- and RV-GLS) on cardiovascular magnetic resonance feature tracking (CMR-FT) is unknown. Methods Consecutive M-TEER patients underwent pre-procedural and follow-up CMR-FT analysis. Kaplan-Meier estimates and multivariable Cox-regression analyses were performed, using a composite endpoint of heart failure hospitalization (HFH) and death. Results 62 patients (78.3±7.0y/o, 45% female, EuroSCORE-II: 9.6±7.1%) underwent CMR-FT prior to M-TEER, 24% had concomitant tricuspid edge-to-edge repair (T-TEER). On presentation, 23 (37%) patients suffered RVD, defined as RV-GLS &amp;gt;-20% on CMR-FT. RVD was associated with reduced LV and RV ejection fraction (LVEF: 39 vs. 49%, p=0.01, RVEF: 35 vs. 47%, p&amp;lt;0.01), as well as impaired LV-GLS (-14.0 vs. -19.5%, p=0.01). Eighteen events (12 deaths, 6 HFH) occurred during follow-up (11.4±9.1months). On multivariable Cox-regression adjusted for baseline, procedural, imaging, and biomarker data, RV but not LV-GLS was significantly associated with outcome (adj.HR 2.50, 95% CI: 1.29-4.86, p=0.01 and 1.46, 95% CI: 0.50-4.28, p=0.49, respectively). Among various definitions of RVD on echocardiography and CMR, only RV-GLS on CMR-FT was significantly associated with outcome (RV-GLS &amp;gt;-20%: adj.HR 7.53, 95% CI: 2.07-27.42, p&amp;lt;0.01), but not RVEF on CMR or echo-indices of RV function. Follow-up CMR-FT was performed in 21 (34%) patients and RV-GLS significantly improved after TMVR (-20.6 to -25.2%, p=0.02), irrespective of additional T-TEER. Conclusions RV-GLS, as determined on CMR-FT, rather than LV-GLS or RVEF, is an independent predictor of outcome in patients undergoing M-TEER.Central Illustration

Left atrial stiffness in patients with severe aortic stenosis: a novel approach

Abstract Background Left atrial (LA) stiffness index is a non-invasive transthoracic echocardiography (TTE) measure that combines left ventricle filling pressure (E/e’) and LA strain at reservoir (LAS_r)(1-3). LAS assessment using cardiac magnetic resonance feature tracking (CMR-FT) is feasible and reproducible(4, 5), and may have advantages over TTE. CMR-modelled pulmonary capillary wedge pressure (PCWP) has recently been validated and shown to be of prognostic value in heart failure(6). We investigate the feasibility of assessing LA stiffness index using novel approaches (CMR and hybrid TTE and CMR) in patients with severe aortic stenosis (AS) compared to controls. Method Patients with severe AS and matched controls were prospectively recruited. CMR and TTE scans were performed on the same day. LAS_r was assessed on 4- and 2-chamber long-axis images, and average value was calculated. Images were analysed using TomTec-ARENA (v2.4) for speckle tracking echocardiography (STE), whereas Medis Suite (v3.1) was used for FT-CMR by a blinded single observer. CMR-modelled PCWP was calculated as: 6.1352 + (0.07204 ∗ LAV) + (0.02256 ∗ LVM), where LAV=left atrial maximum volume and LVM=left ventricle mass by CMR(6). LA stiffness index calculated by (i) TTE: E/e’/LAS_r, using LAS by STE; (ii) TTE-CMR hybrid: E/e’/LAS_r, using LAS by FT-CMR; (iii) CMR: CMR PCWP/LAS_r, using LAS by FT-CMR (Figure). Result Patients with severe AS (n=78, mean age 67.1±9.4 years; 74% males) were well matched to the controls (n=19) for demographics and body size. Patients demonstrated significantly higher filling pressures, lower LAS, higher LAV and LVM. All measures of LA stiffness were significantly higher in patients with AS than matched controls (Table). The correlation between TTE and CMR measured LA stiffness was fair (r=0.46, p-value &amp;lt;0.001), moderate between CMR and TTE-CMR hybrid (r=0.71, p-value &amp;lt;0.001) and strong correlation between TTE and TTE-CMR hybrid (r=0.86, p-value &amp;lt;0.001). Conclusion Non-invasively estimated LA stiffness obtained by TTE, CMR or hybrid are feasible in patients with severe AS, and demonstrates higher stiffness index compared to matched controls.Table 1Figure 1

Dynamic changes in cardiac morphology, function, and diffuse myocardial fibrosis duration of diabetes in type 1 and type 2 diabetic mice models using 7.0 T CMR and echocardiography.

Diabetes mellitus (DM) is associated with an increased risk of cardiovascular disease (CVD). Hence, early detection of cardiac changes by imaging is crucial to reducing cardiovascular complications. Early detection of cardiac changes is crucial to reducing cardiovascular complications. The study aimed to detect the dynamic change in cardiac morphology, function, and diffuse myocardial fibrosis(DMF) associated with T1DM and T2DM mice models. 4-week-old C57Bl/6J male mice were randomly divided into control (n=30), T1DM (n=30), and T2DM (n=30) groups. A longitudinal study was conducted every 4 weeks using serial 7.0T CMR and echocardiography imaging. Left ventricular ejection fraction (LV EF), tissue tracking parameters, and DMF were measured by cine CMR and extracellular volume fraction (ECV). Global peak circumferential strain (GCPS), peak systolic strain rate (GCPSSR) values were acquired by CMR feature tracking. LV diastolic function parameter (E/E') was acquired by echocardiography. The correlations between the ECV and cardiac function parameters were assessed by Pearson's test. A total of 6 mice were included every 4 weeks in control, T1DM, and T2DM groups for analysis. Compared to control group, an increase was detected in the LV mass and E/E' ratio, while the values of GCPS, GCPSSR decreased mildly in DM. Compared to T2DM group, GCPS and GCPSSR decreased earlier in T1DM(GCPS 12W,P=0.004; GCPSSR 12W,P=0.04). ECV values showed a significant correlation with GCPS and GCPSSR in DM groups. Moreover, ECV values showed a strong positive correlation with E/E'(T1DM,r=0.757,P<0.001;T2DM, r=0.811,P<0.001). The combination of ECV and cardiac mechanical parameters provide imaging biomakers for pathophysiology, early diagnosis of cardiac morphology, function and early intervention in diabetic cardiomyopathy in the future.

Abstract 14427: Subclinical Age- and Sex-Differences in Ventricular Strain in the Community: A Framingham Heart Study Cardiac Magnetic Resonance Study

Introduction: Myocardial strain is a measure of deformation and a marker of cardiovascular disease (CVD). The subclinical age- and sex-associations of left and right ventricular (LV, RV) strain by feature tracking cardiovascular magnetic resonance (FT-CMR) are not well established in the community. Methods: Framingham Heart Study Offspring cohort participants (n=1077) without prevalent CVD, hypertension, diabetes, or use of treatment for these conditions underwent 1.5T CMR. Steady-state free precession cine images spanning the entirety of both ventricles were acquired in the short-axis, 2-chamber, and 4-chamber views. Global longitudinal (GLS), circumferential (GCS), and radial (GRS) strains were measured by FT-CMR (Circle cvi42 v.5.11.1). Comparisons among age groups (&lt;45 years, 45-54 years, 55-65 years, and &gt;65 years) were performed by one-way analysis of variance and between sexes by independent samples t -test. Results: Clinical characteristics, CMR measures, and LV and RV strain by age and sex for the cohort are presented in the Table . Across increasing age groups, we observed more favorable LV GLS, GCS, and GRS (p=0.010, p&lt;0.001, and p&lt;0.001, respectively). Similar trends were present for RV strain for GCS and GRS (both p&lt;0.001) but not GLS (p=0.22). Compared with men, women had greater magnitude (more favorable) LV and RV strain values for GLS, GCS, and GRS (all p≤0.013). Conclusions: In this large community based study of individuals without CVD, LV and RV strains by FT-CMR were greater (more favorable) with increasing age and in women. The associations and long-term implications of these differences in myocardial mechanics between groups require further investigation.

Abstract 15568: Myocardial Strain Assessment for Comprehensive Risk Prediction in Patients Following Acute Myocardial Infarction

Background: Cardiovascular magnetic resonance-feature tracking (CMR-FT) derived strain analyses provide incremental prognosticbenefit in patients following acute myocardial infarction (AMI). This study aimed to evaluate and re-validate previously reportedprognostic implications of comprehensive strain analyses in a large independent cohort of patients with ST-elevation myocardialinfarction (STEMI). Methods: Overall, 566 STEMI patients of the CONDITIONING-LIPSIA trial including pre-/postconditioning treatment and/orconventional percutaneous coronary intervention underwent CMR imaging in median 3 days after primary percutaneous coronaryintervention. CMR-based left atrial (LA) reservoir (Es), conduit (Ee) and boosterpump (Ea) strain as well as left ventricular (LV)global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain analyses were carried out. Previously identified cut-offvalues were revalidated for risk stratification. Major adverse cardiac events (MACE) comprising death, reinfarction and newcongestive heart failure were assessed within 12 months after the index event. Results: Both atrial and ventricular strain values were significantly reduced in patients with MACE (p&lt;0.01 for all). PredeterminedLA and LV strain cut-offs enabled accurate risk assessment. All LA and LV strain values were associated with MACE on univariableregression modeling (p&lt;0.001 for all) with LA Es emerging as independent predictor of MACE on multivariable regression modeling(HR 0.92, p=0.033). Furthermore, LA Es provided an incremental prognostic value above LVEF (c-index increase from 0.7 to 0.74,p=0.03). Conclusion: External validation of CMR-FT-derived LA and LV strain evaluations confirmed the prognostic value of cardiacdeformation assessment in STEMI patients. Within the current study especially LA strain parameters enabled further riskstratification and prognostic assessment over and above clinically established risk parameters.

Abstract 16260: Children With Increased Native T1, Extracellular Volume and T2 Values on Initial Cardiac Magnetic Resonance Imaging for Acute Myocarditis Have Less Improvement in Late Gadolinium Enhancement on Follow Up Imaging: Risk Factor for Adverse Events?

Introduction: Late gadolinium enhancement (LGE) in pediatric patients with acute myocarditis has been shown to be a risk factor for adverse events. On follow up cardiac magnetic resonance imaging (CMR), some patients show improvement and/or resolution of LGE but others do not. Factors associated with residual LGE have not been described. Hypothesis: Measurements on initial CMR would be associated with degree of improvement of LGE on follow up CMR. Methods: We conducted a retrospective cohort study of patients &lt;21 years with acute myocarditis who underwent initial CMR within 14 days of presentation and returned for follow up CMR. Those who suffered cardiac arrest or with autoimmune disease, known cardiomyopathy or congenital heart disease were excluded. LGE was defined as tissue with signal intensity 5 standard deviations above mean signal intensity of unaffected myocardium on viability imaging; this mass was measured and indexed to total left ventricular mass. Strain was measured using CMR feature tracking. Spearman’s correlation was used to determine associations between change in indexed LGE mass on follow up CMR to values from initial CMR. Results: We enrolled 36 patients aged 16.4 years (IQR 14.9-17.2 years) with median time to follow up CMR 229 days (IQR 171, 407). Native T1 (Figure 1), T2, peak T2 relaxation times and ECV on initial CMR inversely correlated with change in indexed LGE mass on follow up CMR while indexed right ventricular end diastolic volume (RVEDVi) on initial CMR positively correlated. (Table 1) Strain and ventricular function did not correlate with change in LGE mass on follow up CMR. Conclusions: Elevated T1 and T2 values and ECV on initial CMR in patients with acute myocarditis are associated with less improvement of LGE on follow up CMR; increased RVEDVi was associated with greater improvement. Further work is needed to determine which are the most useful predictors of residual LGE following myocarditis in children.

Sex-Related Differences of Left Atrial Strain in Patients With Hypertension Using Cardiac Magnetic Resonance Feature Tracking.

Previous studies demonstrated the impact of sex on left ventricular (LV) strain in patients with essential hypertension. However, little is known about the effect of sex on left atrial (LA) strain in patients with hypertension. This study aimed to explore the sex-related differences of LA strain by using cardiac magnetic resonance feature tracking in patients with hypertension and preserved LV ejection fraction. One hundred and fifty hypertensive patients (100 men and 50 women) and 105 age-matched and sex-matched normotensive controls (70 men and 35 women) were retrospectively enrolled and underwent cardiac magnetic resonance examination. LA strain parameters included LA reservoir strain (εs), conduit strain (εe), pump strain (εa), and their corresponding strain rate (SRs, SRe, and SRa). Men had significantly higher LV mass index, lower εs and εe than women in both patients and controls (all P <0.05). LA strain and strain rate were significantly reduced in hypertensive patients compared with controls, both in men and women (all P <0.05). In men, hypertension and its interaction were associated with increased LV mass index and decreased εs and εe. In multivariable analysis, men, LV ejection fraction, and LA minimum volume index remained independent determinants of εs and εe in all hypertensive patients (all P <0.05). LA strain was significantly impaired in hypertensive patients, and men had more impaired LA strain than women. These findings further emphasize the sex-related differences in the response of LA strain to hypertension in the early stage.

Impact of temporal and spatial resolution on atrial feature tracking cardiovascular magnetic resonance imaging

BackgroundMyocardial deformation assessment by cardiovascular magnetic resonance-feature tracking (CMR-FT) has incremental prognostic value over volumetric analyses. Recently, atrial functional analyses have come to the fore. However, to date recommendations for optimal resolution parameters for accurate atrial functional analyses are still lacking. MethodsCMR-FT was performed in 12 healthy volunteers and 9 ischemic heart failure (HF) patients. Cine sequences were acquired using different temporal (20, 30, 40 and 50 frames/cardiac cycle) and spatial resolution parameters (high 1.5 × 1.5 mm in plane and 5 mm slice thickness, standard 1.8 × 1.8 × 8 mm and low 3.0 × 3.0 × 10 mm). Inter- and intra-observer reproducibility were calculated. ResultsIncreasing temporal resolution is associated with higher absolute strain and strain rate (SR) values. Significant changes in strain assessment for left atrial (LA) total strain occurred between 20 and 30 frames/cycle amounting to 2,5–4,4% in absolute changes depending on spatial resolution settings. From 30 frames/cycle onward, absolute strain values remained unchanged. Significant changes of LA strain rate assessment were observed up to the highest temporal resolution of 50 frames/cycle. Effects of spatial resolution on strain assessment were smaller. For LA total strain a general trend emerged for a mild decrease in strain values obtained comparing the lowest to the highest spatial resolution at temporal resolutions of 20, 40 and 50 frames/cycle (p = 0.006–0.046) but not at 30 frames/cycle (p = 0.140). ConclusionTemporal and to a smaller extent spatial resolution affect atrial functional assessment. Consistent strain assessment requires a standard spatial resolution and a temporal resolution of 30 frames/cycle, whilst SR assessment requires even higher settings of at least 50 frames/cycle.

Left ventricular dyssynchrony measured by cardiovascular magnetic resonance-feature tracking in anterior ST-elevation myocardial infarction: relationship with microvascular occlusion myocardial damage.

Cardiovascular magnetic resonance-feature tracking (CMR-FT) enables quantification of myocardial deformation and may be used as an objective measure of myocardial involvement in ST-elevation myocardial infarction (STEMI). We sought to investigate the associations between myocardial dyssynchrony parameters and myocardium damage for STEMI. We analyzed 65 patients (45-80 years old) with anterior STEMI after primary percutaneous coronary intervention during 3-7 days [observational (STEMI) group] and 60 healthy volunteers [normal control (NC) group]. Myocardial dyssynchrony parameters were derived, including global and regional strain, radial rebound stretch and displacement, systolic septal time delay, and circumferential stretch. CMR characteristics, including morphologic parameters such as left ventricular ejection fraction (LVEF) (45.3% ± 8.2%) and myocardium damage in late gadolinium enhancement (LGE) (19.4% ± 4.7% LV), were assessed in the observation group. The global radial strain (GRS) and global longitudinal strain (GLS) substantially decreased in anterior STEMI compared with the NC group (GRS: 19.4% ± 5.1% vs. 24.8% ± 4.0%, P < 0.05; GLS: -10.1% ± 1.7% vs. -13.7% ± 1.0%, P < 0.05). Among 362 infarcted segments, radial and circumferential peak strains of the infarcted zone were the lowest (14.4% ± 3.2% and -10.7% ± 1.6%, respectively). The radial peak displacement of the infarct zone significantly decreased (2.6 ± 0.4 mm) (P < 0.001) and manifested in the circumferential displacement (3.5° ± 0.7°) in the STEMI group (P < 0.01). As microvascular occlusion (MVO) was additionally present, some strain parameters were significantly impaired in LGE+/MVO+ segments (radial strain [RS]: 12.2% ± 2.1%, circumferential strain [CS]: -9.6% ± 0.7%, longitudinal strain [LS]: -6.8% ± 1.0%) compared to LGE+/MVO- (RS: 14.6% ± 3.2%, CS: -10.8% ± 1.8%, LS: -9.2% ± 1.3%) (P < 0.05). When the extent of transmural myocardial infarction is greater than 75%, the parameter of the systolic septal delay (mean, 148 ms) was significantly reduced compared to fewer degrees of infarction (P < 0.01). In anterior STEMI, the infarcted septum swings in a bimodal mode, and myocardial injury reduces the radial strain contractility. A more than 75% transmural degree was the septal strain-contraction reserve cut-off point.

Evaluation of left ventricular diastolic function in patients with coronary microvascular dysfunction via cardiovascular magnetic resonance feature tracking.

Coronary microvascular dysfunction (CMD) has been suggested to be one of the pathologic mechanisms contributing to heart failure with preserved left ventricular ejection fraction (LVEF) and left ventricular (LV) diastolic dysfunction. We therefore aimed to evaluate LV diastolic function in patients with CMD using cardiovascular magnetic resonance feature tracking (CMR-FT). We prospectively enrolled 115 patients referred to cardiology clinics for chest pain assessment who subsequently underwent coronary computed tomography angiogram and stress perfusion CMR. CMD was defined as the presence of subendocardial inducible ischemia detected through visual assessment. LV diastolic function was evaluated using CMR-derived volume-time curves and CMR-FT parameters. The former included early peak filling rate (PFR) and time to PFR; the latter included LV global/regional peak longitudinal diastolic strain rate (LDSR), circumferential diastolic strain rate (CDSR), and radial diastolic strain rate (RDSR). A total of 92 patients with 1,312 segments were eventually included. Of these, 19 patients were classified as non-CMD (48.8±11.2 years; 63.2% male) and 73 as with CMD (52.3±11.9 years; 54.8% male). The LVEFs were similar and preserved in both groups (P=0.266). At the per-patient level, no differences were observed in PFR, time to PFR, or LV global diastolic strain rates between the two groups. At the per-segment level, 51% (665/1,312) of the myocardial segments were classified as CMD, whereas 49% (647/1,312) were classified as non-CMD. CMD segments showed significantly lower regional CDSR (P=0.019) and RDSR (P=0.006) compared with non-CMD segments. Despite normal LV ejection fraction in CMD patients, decreased LV diastolic function in CMD myocardial segments indicates early diastolic impairment.

Territorial Post-Revascularization Remodeling of Chronic Coronary Syndromes: Cardiac Magnetic Resonance Feature Tracking Study.

MRI feature-tracking (MRI-FT) can accurately assess ventricular myocardial deformation and regional function and may be a better predictor of mortality than ejection fraction and infarct extension. However, role of MRI-FT in assessing coronary revascularization is unclear. To assess coronary revascularization effect on territorial left ventricle (LV) function of chronic coronary syndrome (CCS) patients by MRI-FT. Prospective. 50 CCS patients (age: 62.22 ± 8.70 years) scheduled for elective percutaneous coronary intervention (PCI), and 30 healthy controls (age: 35.33 ± 11.57 years). 1.5T with balanced steady-state free precession cine sequence. Global and segmental peak systolic longitudinal, circumferential, and radial myocardial strains were quantified in both patient and healthy control groups by an experienced operator using dedicated software. Patients were studied both pre-PCI and 6-month post-PCI and LV territorial myocardial strain values were calculated by averaging the segmental values of each revascularized territory. Student's t-test, paired t-test, Mann Whitney test, and Wilcoxon signed ranks test. Significance was judged at the 5% level. Territorial longitudinal strain showed significant 6-month post-PCI improvement in the left anterior descending (LAD) and right coronary artery (RCA) territories, but there was not in the left circumflex (LCX) territory (LAD: mean - 11.41% ± 3.45% pre, -13.01% ± 3.53% post; RCA: mean - 11.11% ± 2.65% pre, -13.25% ± 2.81% post; and LCX: mean - 15.43% ± 3.97% pre, -16.17% ± 4.38% post, P = 0.215). Territorial circumferential strain showed significant post-PCI improvement in all revascularized territories (LAD: mean - 13.73% ± 6.56% pre, -16.98% ± 6.01% post; LCX: mean - 13.23% ± 4.23% pre, -16.34% ± 3.45% post; and RCA: mean - 11.24% ± 3.36% pre, -13.80% ± 3.51% post). Territorial radial strain showed no significant post-PCI improvement (LAD: mean 22.73% ± 12.38% pre, 21.79% ± 11.55% post, P = 0.541; LCX: mean 27.73% ± 7.95% pre, 29.0% ± 7.25% post, P = 0.264; and RCA: mean 36.68% ± 11.10% pre, 31.75% ± 10.95% post, P = 0.208). Territorial LV systolic function was significantly improved by coronary revascularization in CCS patients. 1 TECHNICAL EFFICACY: Stage 4.

The potential predictive value of cardiac mechanics for left ventricular reverse remodelling in dilated cardiomyopathy.

Left ventricular reverse remodelling (LVRR) is an important objective of optimal medical management for dilated cardiomyopathy (DCM) patients, as it is associated with favourable long-term outcomes. Cardiac magnetic resonance (CMR) can comprehensively assess cardiac structure and function. We aimed to assess the CMR parameters at baseline and investigate independent variables to predict LVRR in DCM patients. Nighty-eight initially diagnosed DCM patients who underwent CMR and echocardiography examinations at baseline were included. CMR parameters and feature tracking (FT) based left ventricular (LV) global strain (nStrain) and nStrain indexed to LV cardiac mass index (rStrain) were measured. The predictors of LVRR were determined by multivariate logistic regression analyses. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic performance of CMR parameters and were compared by the DeLong test. At a median follow-up time of 9 [interquartile range, 7-12] months, 35 DCM patients (36%) achieved LVRR. The patients with LVRR had lower LV volume, mass, LGE extent and stroke volume index (LVSVi) and higher left ventricular remodelling index (LVRI), nStrains, rStrains, and peak systolic strain rate (PSSR) in the longitudinal direction and rStrains in the circumferential direction at baseline (all P<0.05). In the multivariate logistic regression analyses, LVRI [per SD, odds ratio (OR) 1.79; 95% confidence interval (CI) 1.08-2.98; P=0.024] and the ratio of global longitudinal peak strain (rGLPS) (per SD, OR 1.88; 95% CI 1.18-3.01; P=0.008) were independent predictors of LVRR. The combination of LVSVi, LVRI, and rGLPS had a greater area under the curve (AUC) than the combination of LVSVi and LVRI (0.75 vs. 0.68), but not significantly (P=0.09). Patients with LVRR had a lower LV volume index, lower LVSV index, lower LGE extent, higher LVRI, and preserved myocardial deformation in the longitudinal direction at baseline. LVRI and rGLPS at baseline were independent determinants of LVRR.

Biventricular Tissue Tracking with Cardiovascular Magnetic Resonance: Reference Values of Left- and Right-Ventricular Strain.

We derived reference values of left-ventricular (LV) and right-ventricular (RV) strain parameters in a cohort of 100 healthy subjects by feature tracking cardiac magnetic resonance (FT-CMR). Global and regional strain values were calculated for the LV; circumferential and radialSAX strain parameters were derived from the short-axis (SAX) stack, while longitudinal and radialLAX strain parameters were assessed in three long-axis (LAX) views. Only global longitudinal strain (GLS) was calculated for the RV. Peak global LV circumferential strain was -16.7% ± 2.1%, LV radialSAX strain was 26.4% ± 5.1%, LV radialLAX strain was 31.1% ± 5.2%, LV GLS was -17.7% ± 1.9%, and RV GLS was -23.9% ± 4.1%. Women presented higher global LV and RV strain values than men; all strain values presented a weak relationship with body surface area, while there was no association with age or heart rate. A significant association was detected between all LV global strain measures and LV ejection fraction, while RV GLS was correlated to RV end-diastolic volume. The intra- and inter-operator reproducibility was good for all global strain measures. In the regional analysis, circumferential and radial strain values resulted higher at the apical level, while longitudinal strain values were higher at the basal level. The assessment of cardiac deformation by FT-CMR is feasible and reproducible and gender-specific reference values should be used.

Left atrial remodeling in hypertrophic cardiomyopathy and Fabry disease: A CMR-based head-to-head comparison and outcome analysis

BackgroundHypertrophic cardiomyopathy (HCM) and Fabry disease cardiomyopathy (FD) are phenocopies, as they show left ventricular hypertrophy (LVH). The left atrium (LA) is emerging as a potential marker of disease severity in both cardiomyopathies. The present study compares HCM and FD cardiomyopathy with similar degree of LVH, exploring LA morpho-functional parameters and the correlates of clinical outcome. MethodsWe performed a comprehensive CMR-based comparison between 30 HCM and 30 FD patients matched on age, sex, BSA, LV mass and major cardiovascular risk factors affecting LA remodeling (arterial hypertension and diabetes). 30 healthy controls were also included. CMR feature tracking (CMR-FT) analysis, T1 mapping and conventional parameters were evaluated. Patients also underwent transthoracic echocardiography for LV diastolic function assessment. Clinical events at follow-up were collected (atrial and ventricular events, bradyarrhythmia, heart failure (HF) hospitalization and death). ResultsHCM patients showed greater LA remodeling compared to FD patients, namely higher LA end-systolic volume index (LAVi max), lower LA-ejection fraction (LA-EF) and worse reservoir (εs) and booster function (εa) (all p < 0.05). Accordingly, these parameters have demonstrated good potential for distinguishing between FD and HCM (AUC 0.68–0.73, all p < 0.05), with LAVi max being an independent predictor for HCM diagnosis (OR 1.07, 95%CI 1.011–1.132, p 0.02). Moreover, in HCM patients a significant association between εs and HF occurrence was observed at 2-year follow-up (OR 0.85, 95%CI 0.72–0.99, p 0.04). ConclusionsIn HCM, LA remodeling is greater than in FD cardiomyopathy with similar LVH, and reservoir strain is associated with HF at follow-up.