Cardiac Magnetic Resonance Feature Tracking Research Articles

Using cardiac magnetic resonance feature tracking to discover novel abnormalities in patients with idiopathic ventricular fibrillation

Abstract Background Despite an extensive diagnostic work-up, the underlying diagnosis leading to ventricular fibrillation (VF) remains elusive in patients with idiopathic VF. Emerging diagnostic techniques can be used to discover previously unidentified abnormalities in these patients. Purpose The purpose of this study was to investigate the potential of cardiac magnetic resonance feature tracking (CMR-FT) to discover structural abnormalities in idiopathic VF patients. Methods Cine CMR images of idiopathic VF patients and age and sex matched controls were analyzed. Left ventricle global circumferential strain (GCS), global longitudinal strain (GLS) and global radial strain (GRS) were determined using Circle Cardiovascular Imaging. Student’s t-test was used to compare means. Results In total, 26 idiopathic VF patients (mean age 37 (±13) years, 62% male) and 26 controls (mean age 38 (±13) years) were included. CMR was performed in idiopathic VF patients at a median of 9 [IQR 3 – 15] days after the index event. Left ventricle ejection fraction was 55 ± 6% for idiopathic VF patients, 59 ± 6% for controls, p = 0.04. GCS and GRS were comparable for idiopathic VF patients and controls (-17.36 ± 1.78% vs. -18.04 ± 1.83%, p = 0.182 and 28.28 ± 4.63 vs. 29.29 ± 5.09, p = 0.438, respectively). GLS was lower for idiopathic VF patients compared with controls (-14.85 ± 3.21% vs. -18.44 ± 2.11%, p < 0.001). Conclusion CMR-FT GLS distinguished idiopathic VF patients from controls and could imply subclinical abnormalities in idiopathic VF patients. Future studies with a larger cohort should reveal if this finding can be correlated with an arrhythmic substrate.

Impairment of Left Ventricular Function in the Depressed Chinese Miniature Swine Model by Cardiovascular Magnetic Resonance Feature-Tracking: A Preliminary Study.

Individuals with depression have an increased risk of cardiovascular disease, and more often have a poor prognosis with cardiovascular disease. This study aimed to investigate the impact of depression on Left Ventricular (LV) alterations using Cardiovascular Magnetic Resonance Featuretracking (CMR-FT). Seven anesthetized, healthy Chinese miniature swine were included in the study. Basic data, including CMR scans at baseline and after 14 days of depression modeling, were collected. Behavioral tests, including the Open-field Test (OFT), Sucrose Preference Test (SPT), and measurements of the time taken to consume a specific amount of food and sugar, were conducted to assess the success of the depression models. CMR cine images were acquired and CVI software was employed to analyze Global Longitudinal Strain (GLS), Global Circumferential Strain (GCS), and Global Radial Strain (GRS). Late Gadolinium Enhancement (LGE) imaging was used to detect myocardial infarction and/or scar. The outcomes demonstrated successful depression modeling, indicated by reduced scores in the OFT and SPT, as well as an extended time to intake food and sugar compared to baseline. However, no significant differences were observed in LV End-diastolic Volume (LVEDV), LV Endsystolic Volume (LVESV), LV Ejection Fraction (LVEF), LV End-diastolic Myocardial Mass (LVMASSED), and Cardiac Output (CO) before and after modeling. Regarding LV global strain parameters, there was a downward trend in GRS (25.35% ± 6.9% vs. 22.86% ± 6.4%, P=0.021), GCS (-16.71% ± 4.2% vs. -14.78% ± 2.3%, P=0.043), and GLS (-17.66% ± 2.9% vs. -14.53% ± 2.5%, P=0.056), respectively, after modeling. GRS and GCS were significantly reduced after modeling compared to baseline. The study suggests that depression may contribute to early LV systolic dysfunction, particularly affecting LV GCS and GRS.

Feasibility and reproducibility of cardiovascular magnetic resonance-feature tracking for quantitative right atrial function in dilated cardiomyopathy patients.

The importance of right heart assessment in dilated cardiomyopathy (DCM) is increasingly recognized. The development of cardiovascular magnetic resonance-feature tracking (CMR-FT) has provided a novel approach to quantify myocardial deformation and evaluate cardiac function. In this study, we aimed to evaluate the feasibility and reproducibility of CMR-FT for the quantitative derivation of right atrial (RA) strain and strain rate (SR) in patients with DCM. A total of 68 DCM patients (84% male; aged 50.6±13.2 years) and 58 healthy controls (81% male; aged 48.4±11.2 years) were retrospectively enrolled from September 2018 to August 2022 at the First Affiliated Hospital of Zhejiang Chinese Medical University and Shenzhen Clinical Medical College of Guangzhou University of Chinese Medicine. RA reservoir, conduit, and booster strain (εs, εe, and εa) and peak positive, peak early negative, and peak late negative SR (SRs, SRe, and SRa) were measured using CMR-FT and compared between 2 groups using Student's t-test. Intra- and inter-observer reproducibility was evaluated using intraclass correlation coefficients (ICC) and Bland-Altman plots. Compared to healthy controls, DCM patients showed significantly lower RA strain (εs: 19.7%±9.0% vs. 44.4%±9.7%; εe: 7.9%±5.3% vs. 25.8%±8.6%; εa: 11.8%±6.2% vs. 18.6%±5.1%, all P<0.001) and SR (SRs: 1.17±0.48 vs. 1.92±0.62 s-1; SRe: -0.85±0.56 vs. -1.94±0.63 s-1; SRa: -1.39±0.71 vs. -2.01±0.65 s-1, all P<0.001). There was no significant difference in RA maximum volume index between the 2 groups. Simple linear regression analysis demonstrated a significant correlation between N-terminal B-type natriuretic peptide (NT-proBNP), RA emptying fraction passive (RAEF passive), and RA εe [(NT-proBNP and εe): r=-0.48, P<0.001, 95% confidence interval (CI): -0.64 to -0.26; and (RAEF passive and εe): r=0.41, P=0.001, 95% CI: 0.22 to 0.56, respectively] in DCM patients. Intra- and inter-observer reproducibility was excellent (all ICCs >0.85) for RA deformation measurements. CMR-FT is a promising, noninvasive approach for the quantitative assessment of RA phasic function in patients with DCM. DCM patients exhibit impaired RA reservoir, conduit, and booster pump function prior to visible RA enlargement.

Left atrial and left ventricular strain in feature-tracking cardiac magnetic resonance for predicting patients at high risk of sudden cardiac death in hypertrophic cardiomyopathy.

Sudden cardiac death (SCD) represents the most severe complication of hypertrophic cardiomyopathy (HCM). The risk stratification of SCD in patients with HCM remains a subject of ongoing debate, and the utility of left atrial (LA) and left ventricular (LV) myocardial strain for risk stratification of also SCD remains uncertain. Through use of feature-tracking cardiac magnetic resonance (FT-CMR), this study aimed to investigate the attenuation of LA and LV strain in HCM and to assess their predictive value in SCD. This retrospective and cross-sectional study included patients with HCM who underwent 3.0 T cardiac magnetic resonance (CMR) at a single institution. Feature-tracking strain analysis was conducted to obtain the strain rate (SR) and LV strain and to evaluate LV function. LA strain was measured during different functional phases including left atrial reservoir strain (LARS), LA conduit strain (LACS), and LA booster strain. All patients were categorized into high- and low-risk groups for SCD as defined by the 2020 American Heart Association/American College HCM implantable cardioverter defibrillator class of recommendation algorithm. Comparison between the two groups was conducted using the independent samples t test and the nonparametric rank sum test. Multivariate logistic regression analysis was performed to further identify the factors influencing SCD risk in HCM. Compared with those in the low-risk group, patients in the high-risk group had lower left ventricular ejection fraction (LVEF), LV stroke volume index (LVSVI), and LA stroke volume index (LASVI) but a higher LV end-systolic volume index (LVESVI), LV maximum wall thickness, and late gadolinium enhancement (LGE) (P<0.001). LV strain, SR, and LA strain all showed significant differences between the high- and low-risk groups (LARS: P=0.04; LACS: P=0.02; all other P values <0.001). The LV global circumferential strain (LVGCS) had a strong negative correlation with LVEF in patients with HCM (r=-0.76; P<0.001). Multivariate analysis showed that LV global radial strain (LVGRS) and LARS could be used for categorizing the patients into the high-risk group [LVGRS: odds ratio (OR) =0.69; 95% confidence interval (CI): 0.55-0.87, P<0.001; LARS: OR =1.39; 95% CI: 1.02-1.90, P=0.03]. The combined LVGRS-LARS model exhibited a superior diagnostic value for high risk of SCD [area under the curve (AUC) =0.95; 95% CI: 0.90-1.00; P<0.001] compared to LARS alone (AUC =0.63; 95% CI: 0.51-0.76; P=0.04). LA and LV strain measured by FT-CMR can accurately identify those patients with HCM at a high risk of SCD. This approach may prove considerably value in guiding early therapeutic intervention with implantable cardioverter-defibrillators (ICDs) to prevent adverse clinical outcomes.

“Interstitial fibrosis is associated with left atrial remodeling and adverse clinical outcomes in selected low-risk patients with hypertrophic cardiomyopathy”

BackgroundCardiovascular magnetic resonance (CMR) extracellular volume (ECV) allows non-invasive detection of myocardial interstitial fibrosis, which may be related to diastolic dysfunction and left atrial (LA) remodeling in hypertrophic cardiomyopathy (HCM). While the prognostic role of LGE is well-established, interstitial fibrosis and LA dysfunction are emerging novel markers in HCM. This study aimed to explore the interaction between interstitial fibrosis by ECV, LA morpho-functional parameters and adverse clinical outcomes in selected low-risk patients with HCM. Methods115 HCM patients and 61 matched controls underwent CMR to identify: i) interstitial fibrosis by ECV in hypertrophied left ventricular LGE-negative remote myocardium (r-ECV); ii) LA indexed maximum (LAVi max) and minimum (LAVi min) volumes, ejection fraction (LA-EF) and strain (reservoir εs, conduit εe and booster εa), by CMR feature-tracking. 2D-echocardiographic assessment of diastolic function was also performed within 6 months from CMR. A composite endpoint including worsening NYHA class, heart failure hospitalization, atrial fibrillation and all-cause death was evaluated at 2.3 years follow-up. HCM patients were divided into two groups, according to r-ECV values of controls. ResultsPatients with r-ECV ≥29% (n = 45) showed larger LA volumes (LAVimax 63 vs. 54 ml/m2, p < 0.001; LAVimin 43 vs. 28 ml/m2, p 〈0001), worse LA function (εs 16 vs. 28%, εe 8 vs. 15%, εa 8 vs. 14%, LA-EF 33 vs. 49%, all p < 0.001) and elevated Nt-proBNP (1115 vs. 382 pg/ml, p = 0.002). LA functional parameters inversely correlated with r-ECV (εs r = −0.54; LA-EF r = −0.46; all p < 0.001) and E/e' (εs r = −0.52, LA-EF r = −0.46; all p < 0.006). r-ECV ≥29% and LAVi min >30 ml/m2 have been identified as possible independent factors associated with the endpoint. ConclusionsIn HCM diffuse interstitial fibrosis detected by increased r-ECV is associated with LA remodeling and emerged as a potential independent predictor of adverse clinical outcomes, on top of the well-known prognostic impact of LGE.

The additive effect of metabolic syndrome on left ventricular impairment in patients with obstructive coronary artery disease assessed by 3.0 T cardiac magnetic resonance feature tracking

BackgroundMetabolic syndrome (MetS) can increase the risk of morbidity and mortality of cardiovascular disease and obstructive coronary artery disease (OCAD), which usually have a poor prognosis. This study aimed to explore the impact of MetS on left ventricular (LV) deformation and function in OCAD patients and investigate the independent factors of impaired LV function and deformation.Materials and methodsA total of 121 patients with OCAD and 52 sex- and age-matched controls who underwent cardiac magnetic resonance scanning were enrolled in the study. All OCAD patients were divided into two groups: OCAD with MetS [OCAD(MetS+), n = 83] and OCAD without MetS [OCAD(MetS−), n = 38]. LV functional and global strain parameters were measured and compared among the three groups. Multivariable linear regression analyses were constructed to investigate the independent factors of LV impairment in OCAD patients. Logistic regression analysis and receiver operating characteristic (ROC) curve analysis were performed to test the prediction efficiency of MetS for LV impairment.ResultsFrom controls to the OCAD(MetS−) group to the OCAD(MetS+) group, LV mass (LVM) increased, and LV global function index (LVGFI) and LV global longitudinal peak strain (GLPS) decreased (all p < 0.05). Compared with the OCAD(MetS−) group, the LV GLPS declined significantly (p = 0.027), the LVM increased (p = 0.006), and the LVGFI decreased (p = 0.043) in the OCAD(MetS+) group. After adjustment for covariates in OCAD patients, MetS was an independent factor of decreased LV GLPS (β = − 0.211, p = 0.002) and increased LVM (β = 0.221, p = 0.003). The logistic multivariable regression analysis and ROC analysis showed that combined MetS improved the efficiency of predicting LV GLPS reduction (AUC = 0.88) and LVM (AUC = 0.89) increase.ConclusionsMetS aggravated the damage of LV deformation and function in OCAD patients and was independently associated with LV deformation and impaired LV strain. Additionally, MetS increased the prediction efficiency of increased LVM and decreased LV GLPS. Early detection and intervention of MetS in patients with OCAD is of great significance.

The Feasibility of Left Ventricular Strain and Strain Rate for Evaluating Hypertrophic Cardiomyopathy with Risk Factors of Sudden Cardiac Death by Feature-Tracking CMR

Sudden cardiac death (SCD) represents the most severe complication of hypertrophic cardiomyopathy (HCM). However, the relation between strain, strain rate (SR), and risk factors in SCD risk stratification remains elusive. The study aimed to assess the attenuation of strain and SR in HCM by feature tracking cardiac magnetic resonance. All strain and SRs were obtained automatically by feature tracking, with manual adjustment of endocardial and epicardial borders. Strain indicators included left ventricular global longitudinal, circumferential, global radial strain (GRS), peak diastolic-longitudinal, circumferential, and radial SR. Patients were categorized into high-risk and low-risk groups for SCD based on the 2020 American Heart Association/American College HCM risk-SCD model. The correlation between strain/SR and SCD risk factors was assessed through Spearman correlation analysis. Furthermore, a multivariate logistic regression analysis was conducted to explore the factors that influence SCD risk in HCM patients. A total of 105 HCM patients were analyzed in this study, including 38 patients in the high-risk group, and 67 patients in the low-risk group. Compared with the low-risk group, the high-risk group exhibited significantly worse strain and SR (p <0.001). Furthermore, both circumferential and GRS and SR exhibited meaningful associations with risk factors for SCD. Additionally, GRS emerged as an independent risk factor for predicting heightened SCD risk in HCM patients (p <0.001). In conclusion, left ventricular strain and SR based on feature tracking-cardiac magnetic resonance can be evaluated for SCD risk and are strongly associated with SCD risk factors.

Abnormal Cardiac Magnetic Resonance-Derived Ascending Aortic Area Strain Demonstrates Altered Ventriculo-Vascular Function in Marfan Syndrome.

There remains a need for improved imaging markers for risk stratification and treatment guidance in Marfan syndrome (MFS). After aortic root replacement (ARR), vascular remodeling and progressive aneurysm formation can occur due to alterations in up- and downstream wall biomechanics and hemodynamics. We aim to compare the ventriculo-vascular properties of patients with MFS with controls, and investigate the correlation between ascending aortic area strain and descending aortic area strain (DAAS) with other clinical variables. Nineteen patients with MFS (47% males), including 6 with ARR were studied. In 26 studies, aortic area strain was measured using cross-sectional cardiac magnetic resonance images at the ascending and proximal descending aortic levels. Left atrial, left ventricular longitudinal, and left ventricle circumferential strain (left atrial longitudinal strain, left ventricular longitudinal strain, and left ventricular circumferential strain, respectively) were measured using cardiac magnetic resonance-feature tracking. Compared with healthy controls, patients with MFS had significantly impaired left ventricular longitudinal strain and left ventricular circumferential strain (-15.8 ± 4.7 vs -19.7 ± 4.8, P = 0.005, and -17.7 ± 4.0 vs -27.0 ± 4.1, P < 0.001). Left atrial longitudinal strain was comparable between patients with MFS and controls. AAAS was significantly reduced (19.0 [11.9, 23.7] vs 46.1 ± 11.3, P < 0.001), whereas DAAS was not significantly decreased. AAAS and DAAS were negatively correlated with age, whereas no significant associations were identified with left ventricle function indices. No significant differences were observed between the ventriculo-vascular properties of patients with MFS who underwent ARR and those who did not. Patients with MFS demonstrated impaired ventricular and vascular function compared with healthy controls. Further investigations are warranted to determine clinical utility of aortic stiffness indices for predicting primary and repeat aortic events.

Assessing right ventricular peak strain in myocardial infarction patients with mitral regurgitation by cardiac magnetic resonance feature tracking.

Although it is known that mitral regurgitation (MR) in patients with myocardial infarction (MI) may increase the right ventricular (RV) afterload, leading to RV dysfunction, the exact detrimental effects on RV function and myocardial peak strain remain unresolved. In this study, we assessed the impact of MR on the impairment of RV myocardial deformation in patients with MI and explored the independent influential factors of RV peak strain. A total of 199 MI participants without or with MR were retrospectively assessed in this study. The cardiovascular magnetic resonance examination protocol included a late gadolinium-enhanced (LGE) imaging technique and a cine-balanced steady-state free precession sequence. Statistical tests, including two independent sample t-test or Mann-Whitney U-test, analysis of variance, Kruskal-Wallis test, and multiple linear regression analysis models were performed. The MI (MR+) group exhibited significantly lower RV strain parameters in the radial, circumferential and longitudinal directions when compared to the control and the MI (MR-) groups (both P<0.05). The RV global longitudinal peak strain (GLPS) in the MI group significantly decreased when compared with that in the control group (P<0.05). As moderate-severe MR worsened in patients with MI, RV myocardial global peak strain and the peak systolic strain rate (PSSR) gradually decreased. Multiple linear regression analysis revealed that left ventricular (LV) GLPS, triglycerides, and age were independently correlated with RV GLPS (all P<0.05). RV end-systolic volume (RVESV) acted as an independent association factor for RV global peak strain. MR may exacerbate the impairment of RV peak strain and functions in patients with MI. LV GLPS was positively correlated with RV GLPS. However, RVESV, triglycerides, and age acted as independent risk factors associated with worsening RV GLPS.

Cardiac magnetic resonance feature tracking derived left atrial strain in the diagnosis of patients with constrictive pericarditis and restrictive cardiomyopathy

ObjectiveTo explore the diagnostic value of cardiac magnetic resonance feature tracking (CMR-FT) divided left atrial (LA) strain in differentiating constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM). MethodsPatients with CP (n = 40) and RCM (n = 40), and another 40 normal control group were retrospectively enrolled over a period of 8 years at a tertiary cardiac centre. Left ventricular (LV) and biatrial strain and strain rate (SR) were measured. Atrial strain was used to differentiate between patients with CP and RCM. Then, patients were grouped according to their left ventricular ejection fraction (LVEF), either ≥50% or < 50%. A deeper analysis was done to evaluate the diagnostic value of atrial strain in these subgroups. Receiver operating characteristic curves (ROC) were used to assess the accuracy of myocardial strain based on CMR FT for the differential diagnosis of CP and RCM. ResultsLV and LA strain and SR were significantly lower in patients with CP and RCM than those in the normal controls (P < 0.05). LA strain and SR were significantly lower in the RCM group than in the CP group (P < 0.05). In patients with either LVEF≥50% or＜50%, LA strain were lower in the RCM group than in the CP group (P < 0.05). ROC analysis showed that LA stored strain (LA-εs) had a good differential diagnostic value for CP and RCM, with an area under the curve (AUC) of 0.811 and an optimal cutoff value of 6.98%, above this value it tends to develop CP. Further, an excellent differential diagnostic value was found in patients with LVEF＜50%, with an AUC of 0.955. ConclusionLA strain analysis obtained by CMR-FT provides good differential diagnostic value for distinguishing CP from RCM, especially in patients with LVEF＜50%.

Myocardial deformation characteristics assessed by cardiovascular magnetic resonance feature tracking in a healthy Chinese population

PurposeTo explore global/regional myocardial deformation across various layers, vascular distributions, specific levels and distinct walls in healthy individuals using cardiovascular magnetic resonance feature tracking (CMR-FT). MethodsWe selected a cohort of 55 healthy participants and CMR cine images were used to obtain the left ventricular (LV) peak longitudinal, circumferential, radial strains (LS, CS, RS). The characteristics of normal LV strain in various layers (endocardium, myocardium, epicardium), territories [left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA)], levels (basal, middle, apical) and walls (anterior, septum, inferior, lateral) were compared. ResultsThe absolute values of the LV global LS and CS gradually decreased from endocardium to epicardium. The absolute LV global RS (65.7 ± 47.7%) was maximum relative to LS (−22.0 ± 10.8%) and CS (−22.8 ± 7.7%). The absolute values of the LCX territorial strain were the largest compared with the LAD and RCA territorial strains. Regional RS, endo-CS and endo-LS gradually increased from the basal to the apical level. The LV lateral walls had the highest strain values (CS, LS, and RS). ConclusionsVariations in normal LV strain values across various layers, territories, levels, and walls were observed, suggesting the necessity for careful clinical interpretation of these strain values. These findings also partially revealed the complexity of normal cardiac mechanics.

Association of serum uric acid with right cardiac chamber remodeling assessed by cardiovascular magnetic resonance feature tracking in patients with connective tissue disease.

Right cardiac chamber remodeling is widespread in patients with connective tissue disease (CTD). Serum uric acid (SUA) is considered a potential independent risk factor for cardiovascular disease, and elevated SUA levels are often observed in patients with CTD. The correlation between SUA levels and right cardiac chamber remodeling remains unclear. This study investigated the association of SUA with right cardiac chamber remodeling as assessed by cardiac magnetic resonance feature-tracking (CMR-FT) in CTD patients. In this cross-sectional study, a total of 104 CTD patients and 52 age- and sex-matched controls were consecutively recruited. All individuals underwent CMR imaging, and their SUA levels were recorded. The patients were divided into three subgroups based on the tertiles of SUA level in the present study. CMR-FT was used to evaluate the right atrial (RA) longitudinal strain and strain rate parameters as well as right ventricular (RV) global systolic peak strain and strain rate in longitudinal and circumferential directions for each subject. Univariable and multivariable linear regression analyses were used to explore the association of SUA with RV and RA strain parameters. Compared with the controls, the CTD patients showed significantly higher SUA levels but a lower RV global circumferential strain (GCS) and RA phasic strain parameters (all p < 0.05), except the RA booster strain rate. RV GCS remained impaired even in CTD patients with preserved RV ejection fraction. Among subgroups, the patients in the third tertile had significantly impaired RV longitudinal strain (GLS), RV GCS, and RA reservoir and conduit strain compared with those in the first tertile (all p < 0.05). The SUA levels were negatively correlated with RV GLS and RV GCS as well as with RA reservoir and conduit strain and strain rates (the absolute values of β were 0.250 to 0.293, all P < 0.05). In the multivariable linear regression analysis, the SUA level was still an independent determinant of RA conduit strain (β = -0.212, P = 0.035) and RV GCS (β = 0.207, P = 0.019). SUA may be a potential risk factor of right cardiac chamber remodeling and is independently associated with impaired RA conduit strain and RV GCS in CTD patients.

Left atrial strain in patients with β-thalassemia major: a cross-sectional CMR study.

The aim of this cross-sectional study was to investigate the association of left atrial (LA) strain parameters with demographics, clinical data, cardiovascular magnetic resonance (CMR) findings, and cardiac complications (heart failure and arrhythmias) in a cohort of patients with β-thalassemia major (β-TM). We considered 264 β-TM patients (133 females, 36.79 ± 11.95 years) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia (E-MIOT) project. Moreover, we included 35 sex- and age-matched healthy controls (14 females, mean age 37.36 ± 17.52 years). Reservoir, conduit, and booster LA functions were analysed by CMR feature tracking using dedicated software. Compared to the healthy control group, β-TM patients demonstrated lower LA reservoir strain and booster strains, as well as LA reservoir and booster strain rates. However, no differences were found in LA conduit deformation parameters. In β-TM patients, ageing, sex, and left ventricle (LV) volume indexes were independent determinants of LA strain parameters. The number of segments with late gadolinium enhancement (LGE) significantly correlated with all LA strain parameters, with the exception of the LA conduit rate. Patients with cardiac complications exhibited significantly impaired strain parameters compared to patients without cardiac complications. In patients with β-TM, LA strain parameters were impaired compared to control subjects, and they exhibited a significant correlation with the number of LV segments with LGE. Furthermore, patients with cardiac complications had impaired left atrial strain parameters. Clinical relevance statement In patients with β-thalassemia major, left atrial strain parameters were impaired compared to control subjects and emerged as a sensitive marker of cardiac complications, stronger than cardiac iron levels. • Compared to healthy subjects, β-thalassemia major patients demonstrated significantly lower left atrial reservoir strain and booster strains, as well as left atrial reservoir and booster strain rates. • In β-thalassemia major, ageing, sex, and left ventricular volume indexes were independent determinants of left atrial strain parameters, while left atrial strain parameters were not correlated with myocardial iron overload. • An independent association between reduced left atrial strain parameters and a history of cardiac complications was found in β-thalassemia major patients.

Evaluation the relationship between myocardial fibrosis and left ventricular torsion measured by cardiac magnetic resonance feature-tracking in hypertrophic cardiomyopathy patients with preserved ejection fraction.

The relationship between left ventricular (LV) torsion and myocardial fibrosis (MF) in hypertrophic cardiomyopathy (HCM) patients with preserved ejection fraction was still not well understood. New developments in cardiac magnetic resonance (CMR) enable a much fuller assessment of cardiac characteristics. This study sought to assess the impact of HCM on myocardial function as assessed by LV torsion and its relationship with MF. HCM (n = 79) and healthy controls (n = 40) underwent CMR. According to whether there was late gadolinium enhancement (LGE), patients were divided into LGE+ group and LGE- group. LV torsion and torsion rate were measured by CMR feature-tracking (CMR-FT). MF was quantitatively evaluated through LGE imaging. LGE was present in 44 patients (56%). Compared with healthy controls, torsion increased in the LGE- group (P < 0.001). Compared with LGE+ group, torsion was higher in the LGE- group (P < 0.001). There was no significant difference in torsion between LGE+ group and healthy controls. Correlation analysis showed that torsion was correlated with LGE% (r= -0.443) and LGE mass (r= -0.435) respectively. On multivariable logistic regression analysis, LV torsion was the only feature that was independently associated with the presence of LGE (OR 0.130; 95% CI 0.040 to 0.420, P = 0.01). The best torsion value associated with MF was 1.91 (sensitivity 60.0%, specificity 77.3%, AUC = 0.733). In HCM patients with preserved ejection fraction, CMR-FT derivedLV torsion analysis holds promise for myocardial fibrosis detection.

The worsening effect of paroxysmal atrial fibrillation on left ventricular function and deformation in type 2 diabetes mellitus patients: a 3.0 T cardiovascular magnetic resonance feature tracking study

BackgroundAtrial fibrillation (AF) has been linked to an increased risk of cardiovascular death, overall mortality and heart failure in patients with type 2 diabetes mellitus (T2DM). The present study investigated the additive effects of paroxysmal AF on left ventricular (LV) function and deformation in T2DM patients with or without AF using the cardiovascular magnetic resonance feature tracking (CMR-FT) technique.MethodsThe present study encompassed 225 T2DM patients differentiated by the presence or absence of paroxysmal AF [T2DM(AF+) and T2DM(AF−), respectively], along with 75 age and sex matched controls, all of whom underwent CMR examination. LV function and global strains, including radial, circumferential and longitudinal peak strain (PS), as well as peak systolic and diastolic strain rates (PSSR and PDSR, respectively), were measured and compared among the groups. Multivariable linear regression analysis was used to examine the factors associated with LV global strains in patients with T2DM.ResultsThe T2DM(AF+) group was the oldest, had the highest LV end‑systolic volume index, lowest LV ejection fraction and estimated glomerular filtration rate compared to the control and T2DM(AF−) groups, and presented a shorter diabetes duration and lower HbA1c than the T2DM(AF−) group. LV PS-radial, PS-longitudinal and PDSR-radial declined successively from controls through the T2DM(AF−) group to the T2DM(AF+) group (all p < 0.001). Compared to the control group, LV PS-circumferential, PSSR-radial and PDSR-circumferential were decreased in the T2DM(AF+) group (all p < 0.001) but preserved in the T2DM(AF−) group. Among all clinical indices, AF was independently associated with worsening LV PS-longitudinal (β = 2.218, p < 0.001), PS-circumferential (β = 3.948, p < 0.001), PS-radial (β = − 8.40, p < 0.001), PSSR-radial and -circumferential (β = − 0.345 and 0.101, p = 0.002 and 0.014, respectively), PDSR-radial and -circumferential (β = 0.359 and − 0.14, p = 0.022 and 0.003, respectively).ConclusionsIn patients with T2DM, the presence of paroxysmal AF further exacerbates LV function and deformation. Proactive prevention, regular detection and early intervention of AF could potentially benefit T2DM patients.

CMR feature tracking–based left atrial mechanics predicts response to cardiac resynchronization therapy and adverse outcomes

BackgroundCardiac resynchronization therapy (CRT) is an established therapy for advanced heart failure (HF) with prolonged QRS duration. However, 30% of patients have shown no benefit from the treatment. ObjectiveThis study aimed to examine the value of left atrial (LA) mechanics by cardiac magnetic resonance (CMR) to predict response to CRT and clinical outcomes. MethodsA total of 163 CRT recipients with preimplantation CMR examination were retrospectively recruited. CMR feature tracking was used to evaluate LA size and function. The end points include (1) improvement of at least 5% in left ventricular ejection fraction combined with a reduction of at least 1 New York Heart Association functional class at 6-month follow-up and (2) any all-cause death or HF hospitalization during follow-up. ResultsOverall, 82 (50.3%) were CRT responders. CRT nonresponders had larger LA and worse LA reservoir and booster pump function than did responders (P < .001 for all). LA structural (maximum volume index < 47 mL/m2) and functional (booster pump strain > 8.5%) criteria were incremental to traditional indicators in detecting CRT response (χ2, 40.83 vs 9.98; P < .001). During follow-up (median 41 months), survival free from death or HF hospitalization increased with the number of positive LA criteria (log-rank, P < .001). After adjustment for clinical confounders, the absence of the 2 criteria remained associated with a considerably increased risk of death or HF hospitalization (adjusted hazard ratio 6.2; 95% confidence interval 2.15–17.88; P = .001). ConclusionThe preprocedure LA mechanics evaluated using CMR may be useful to predict response to CRT and improve risk stratification in CRT recipients.

Quantification of left atrial strain in patients with idiopathic inflammatory myopathy using cardiovascular magnetic resonance feature tracking

Left atrial (LA) dysfunction is involved in idiopathic inflammatory myopathy (IIM). Multiparametric cardiovascular magnetic resonance (CMR) strain imaging is a feasible and reproducible tool for examining global and regional LA functions, as well as left ventricular (LV) function in IIM patients. The aim of this study was to evaluate the feasibility and reproducibility of LA strain occurrence and strain rate for LA function assessment using CMR in IIM cases. A total of 36 IIM and 42 healthy control cases were included. Baseline ventricular function was comparatively assessed in both groups. LA strain occurrence and strain rate were examined by cine cardiac magnetic resonance imaging [MRI] utilizing an in-house semiautomated technique. LA global function indexes were quantitated, including reservoir, conduit, and booster-pump functions. A total of 78 participants were enrolled in this study. There was no significant difference in left/right ventricular routine functions between IIM patients and control individuals (p>0.05); the same results (p>0.05) was also observed between patients with high hs-cTnI and normal. However, LV mass index had significant difference (p1=0.003, p2<0.01). Compared with IIM patients and control individuals, only total strain (εs) (p4=0.046) and passive strain (εe) (p4=0.002) showed significant difference, and in cases with high hs-cTnI and normal hs-cTnI, there are differences for εs (p3=0.012) and εe (p4=0.047). The strongest association was found between εe and LV ejection fraction (LVEF) (r=0.581, p<0.01). IIM cases have altered LA reservoir and conduit functions, and LA strain could reflect LA function.

Relationship between coronary microvascular dysfunction (CMD) and left ventricular diastolic function in patients with symptoms of myocardial ischemia with non-obstructive coronary artery disease (INOCA) by cardiovascular magnetic resonance feature-tracking

To investigate whether there was an association between coronary microvascular dysfunction (CMD) and left ventricular (LV) diastolic function in patients with myocardial ischemia with non-obstructive coronary artery disease (INOCA). Our study included 115 subjects with suspected myocardial ischemia that underwent stress perfusion cardiac magnetic resonance (CMR). They were divided into non-CMD and CMD two groups. CMR-derived volume-time curves and CMR-FT parameters were used to assess LV diastolic function using CVI42 software. The latter included global/regional LV peak longitudinal, circumferential, radial diastolic strain rate (LDSR, CDSR, RDSR). Logistic regression analysis was performed with CMR-FT strain parameters as independent variables and CMD as dependent variables, and the effect value was expressed as an odds ratio (OR). Of the 115 patients, we excluded data from 23 patients and 92 patients (56.5% male；52±12 years) were finally included in the study. Of these, 19 patients were included in the non-CMD group (49±11 years) and CMD group included 73patient (52±12 years). The regional CDSR (P=0.019), and regional RDSR (P=0.006) were significantly lower in the CMD group than in non-CMD group. But, regional LDSR in CMD group was higher than non-CMD (P=0.003). In logistic regression analysis, regional LDSR (adjusted β= 0.1, 95%CI 0.077, 0.349, p=0.002) and RDSR (adjusted β= 0.1, 95 % CI 0.066, 0.356, p=0.004) were related to CMD. LV myocardial perfusion parameter MPRI was negatively correlated with LV diastolic function (CDSR) which needs to take into account the degree of diastolic dysfunction.

Takotsubo syndrome: left atrial and ventricular myocardial strain impairment in the subacute and convalescent phases assessed by CMR.

We investigated the differences in impairment of left ventricle (LV) and left atrium (LA) contractile dysfunction between subacute and convalescent takotsubo syndrome (TTS), using myocardial strain analysis by cardiac magnetic resonance (CMR) feature-tracking technique. We retrospectively selected 50 patients with TTS clinical-radiological diagnosis who underwent CMR within 30days since symptoms onset: 19 studied during the early subacute phase (sTTS, ≤ 7days) and 31 during the convalescence (cTTS, 8-30days). We measured the following: LV global longitudinal, circumferential, and radial strain (lvGLS, lvGCS, lvGRS) and strain rate (SR) and LA reservoir (laS_r), conduit (laS_cd), and booster pump strain (laS_bp) and strain rate (laSR_r, laSR_cd, laSR_bp). Patients were compared with 30 age- and sex-matched controls. All patients were women (mean age 63years). TTS patients showed altered LV- and LA-strain features, compared to controls. sTTS was associated with increased laS_bp (12.7% versus 9.8%) and reduced lvEF (47.4% versus 54.8%), lvGLS (-12.2% versus 14.6%), and laS_cd (7.0% versus 9.5%) compared to cTTS (p ≤ 0.029). The interval between symptoms onset and CMR was correlated with laS_bp (r = -0.49) and lvGLS (r = 0.47) (p = 0.001 for both). At receiver operating characteristics analysis, laS_bp was the best discriminator between sTTS and cTTS (area under the curve [AUC] 0.815), followed by lvGLS (AUC 0.670). LA dysfunction persists during the subacute and convalescence of TTS. laS_bp increases in subacute phase with progressive decrease during convalescence, representing a compensatory mechanism of LV dysfunction and thus a useful index of functional recovery. Atrial strain has the potential to enhance the delineation of cardiac injury and functional impairment in TTS patients, assisting in the identification of individuals at higher risk and facilitating the implementation of more targeted and personalized medical therapies. • In TTS, after ventricular recovery, atrial dysfunction persists assessable with CMR feature tracking. • Quantitative assessment of atrial strain discriminates atrial functions: reservoir, conduit, and booster pump. • Atrial booster pump changes after acute TTS, regardless of ventricular function. • Atrial strain may serve as a temporal marker in TTS.

Prognostic significance of left atrial strain combined with left ventricular strain using cardiac magnetic resonance feature tracking in patients with heart failure with preserved ejection fraction.

We aimed to evaluate the prognostic value of left ventricular global longitudinal strain (LVGLS) and left atrial strain (LAS) obtained from magnetic resonance imaging (MRI) feature tracking in patients with heart failure with preserved ejection fraction (HFpEF). We retrospectively enrolled consecutive patients with HFpEF admitted to our hospital who underwent cardiac MRI. LVGLS and LAS were obtained from cine MRI by feature tracking. The end point was defined as a composite of all-cause death, myocardial infarction, and hospitalization due to decompensated HF. One-hundred patients with HFpEF were enrolled. Mean LVGLS and LAS were -13.7 ± 3.7% and 22.5 ± 11.6%, respectively. During follow-up of 4.4 ± 1.9years, 24 events occurred. Multivariate Cox proportional hazards model analysis demonstrated LAS was independently associated with adverse cardiac events. Kaplan-Meier curve analysis revealed that the patients with both LVGLS and LAS worse than the median (LVGLS ≥ -12.2% and LAS ≤ 13.8%) had a significantly lower event-free rate compared to those with preserved strain (Log-rank P < 0.001). Simultaneous assessment of LVGLS and LAS using MRI was useful for risk stratification in the patients with HFpEF.