Left Ventricular Strain Analysis Research Articles

Left ventricular longitudinal strain analysis using cardiac computed tomography for the diagnosis of cardiac amyloidosis

Abstract Introduction Cardiac amyloidosis (CA) results in a restrictive cardiomyopathy caused by extracellular deposition of proteins in the myocardium, demanding early identification for effective management. Left ventricular (LV) strain, mainly evaluated by echocardiography or cardiac magnetic resonance, provides sensitive and specific indicators for detecting CA, particularly apical sparing. It represents a pattern where the longitudinal strain (LS) in the basal and middle segments of LV is more impaired compared to the apical segments.¹ Cardiac computed tomography (CT) is useful not only for coronary artery evaluation but also for myocardial assessment, including LV ejection fraction (LVEF). Advanced software made it possible to analyse LS on cardiac CT (Figures A,B). Hypothesis: LS analysis using four-dimensional cardiac CT is helpful for the differential diagnosis of LV hypertrophied myocardial diseases and for detecting CA. Methods We analyzed 60 patients with LV hypertrophied myocardial diseases who underwent cardiac CT using 256-detector row or 320-detector row CT since 2009. Twenty patients of them were diagnosed with CA ( 70 ± 10 years, 14 males), the other 20 patients were diagnosed with hypertrophic cardiomyopathy (HCM) ( 60 ± 14 years, 12 males), and the rest of the 20 patients were diagnosed with severe aortic valve stenosis (AS) ( 86 ± 6 years, nine males). We analyzed LV global LS (GLS) and segmental LS using specific software and four-dimensional CT data. We evaluated relative apical LS as the value dividing the average LS of apical segments by the sum of the average LS of basal segments and mid-ventricular segments (Figure C). If the value was ≥ 1, apical sparing was defined as present. We compared the LS data and the percentage of apical sparing among those three myocardial diseases. Results There was no significant difference in LVEF among the three groups (52 ± 14%, 55 ± 27%, and 50 ± 18%, respectively; P = 0.15). There was no significant difference in GLS among the three groups (-10.6 ± 3.6%, -10.2 ± 5.2%, and -11.6 ± 3.8%, respectively; P = 0.87). Apical sparing was observed in 13 cases (65%) of CA, which was significantly higher than 3 cases (15%) of HCM or 4 cases(20%) of AS (P = 0.0002). Conclusions LV strain analysis using cardiac CT is helpful for detecting apical sparing. Advanced image analysis software has enabled LV strain analysis by cardiac CT, which is useful for the differential diagnosis of CA among LV hypertrophied diseases.Figure A,B,C

Identification and validation of ventricular rhythmic risk subgroups in hypertrophic cardiomyopathy by clustering analysis including left ventricular strain analysis

Abstract Background The excess mortality in hypertrophic cardiomyopathy (HCM) patients is mainly attributed to the occurrence of ventricular arrhythmia (VA).The prediction of VA remains challenging and could be improved. Purpose The study aimed to characterize the VA risk profile in HCM patients through clustering analysis combining conventional parameters with information derived from left ventricular longitudinal strain analysis (LV-LS). Methods 434 HCM patients (65% men, mean age 56 years) were retrospectively included from two referral centers and followed longitudinally (mean duration 6 years). The validation cohort included 177 HCM patients from an other tertiary French center. Mechanical and temporal parameters were automatically extracted from the LV-LS segmental curves of each patient in addition to conventional clinical and imaging data. A total of 287 features were analyzed using a clustering approach (k-means). The first endpoint for VA included suspected SCD, aborted cardiac arrest, appropriate ICD therapy (AIT), sustained ventricular tachycardia (SVT) and non-sustained ventricular tachycardia (NSVT) during follow-up. Results From the derivation cohort, 4 clusters were identified with a higher rhythmic risk for clusters 1 and 4 (VA rates of 26%(28/108), 13%(13/97), 12%(14/120), and 31%(34/109) for cluster 1,2,3 and 4 respectively) (Figure 1). These 4 clusters differed mainly by the LV mechanics. Patients from cluster 4 had a severe and homogeneous decrease of myocardial deformation (global longitudinal strain (GLS) -11%, normal value ≥ -20%) associated with LV and left atrium (LA) remodeling (left atrial volume index (LAVI) 46.6 vs. 41.5 ml/m², p=0.04 and LVEF 59.7 vs. 66.3%, p < 0.001) and impaired exercise capacity (% predicted peak work 58.6 vs. 69.5%; p= 0.025). Patients from cluster 1 showed a marked deformation delay and temporal dispersion on the segmental analysis associated with a moderate decrease of the GLS (-15.3%; p <0.0001 for GLS comparison between clusters). Patients from clusters 2 and 3 had a small GLS decrease (GLS -17.2 and -16.3%, respectively) with a less severe phenotype for cluster 2 and older patients for cluster 3 (mean age 62.1 vs. 54.1 years; p < 0.0001). The clustering analysis in the validation population resulted in the creation of 4 clusters overlapping the derivation cohort with similar characteristics (Figure 2). Clusters 1’ and 4’ had a higher incidence of ventricular arrhythmia with a VA rate of 22%(5/23), 18%(16/88), 0%(0/17), and 20%(10/49) for clusters 1’,2’,3’ and 4’ respectively. Conclusion Machine-learning-based cluster analysis processing LV-LS parameters in HCM patients identified 4 clusters with specific LV-strain patterns and different rhythmic risk levels. In the future, the automatic extraction and analysis of LV strain parameters could help to improve the risk stratification for SCD in HCM patients.Clustering analysisExternal validation

Global and regional cardiac magnetic resonance feature tracking left ventricular strain analysis in assessing early myocardial disease in β thalassemia major patients

BackgroundCardiac magnetic resonance imaging (CMR) is the modality of choice for quantification of myocardial iron overload in β-thalassemia major patients using the T2* sequence. CMR feature tracking (FT) is a recent magnetic resonance imaging tool that gives an idea about myocardial fibers deformation; thus, it can detect early impairment in myocardial function even before the reduction in ejection fraction.MethodsThis study aims to assess the ability of left ventricular CMR-FT in the early detection of systolic dysfunction in β thalassemia major patients and to correlate it with the degree of myocardial iron overload measured by CMR T2*. This prospective study enrolled 57 β thalassemia major patients who received long-term blood transfusion and 20 healthy controls. CMR was used to evaluate left ventricular volumes, ejection fraction, and the amount of myocardial T2*. A two-dimensional left ventricular FT analysis was performed. Both global and segmental left ventricular strain values were obtained.ResultsThe mean global circumferential strain (GCS) and global radial strain (GRS) values were significantly lower in patients compared to control (P = 0.002 and P = 0.006, respectively). No correlation was found between T2* values and ejection fraction; however, there was a significant correlation between T2* values and GCS and GRS (P = 0.012 and P = 0.025, respectively) in thalassemia patients. Regional strain revealed significantly lower values of GCS and GRS in basal regions compared to apical ones (P = 0.000).ConclusionsOur study revealed that CMR-FT can play a role in the early detection of systolic impairment in thalassemia patients.

Advanced Myocardial Characterization in Hypertrophic Cardiomyopathy: Feasibility of CMR-based Feature Tracking Strain Analysis

Abstract Aim of the Work This study aimed to evaluate the role of cardiovascular magnetic resonance feature tracking (CMR-FT) using a commercially available software module for analysis of left ventricular strain in hypertrophic cardiomyopathy patients. Patients and Methods A total of 20 HCM patients and 10 controls were studied. All patients were subjected to detailed clinical history taking and CMRI. Left ventricular global longitudinal, circumferential and radial strains were analyzed as well as segmental longitudinal and circumferential strains. Results LV mass in the HCM group was significantly higher than that in the control group (p < 0.001). No statistical difference was found in ejection fraction (p = 0.074). Global circumferential strain (GCS) global longitudinal strain (GLS), segmental longitudinal strain (SLS) and segmental circumferential strain (SCS) in the HCM group were all significantly lower than the correlated parameters in the control group (p < 0.001, respectively). Global radial strain (GRS) in the HCM group was significantly higher than the control group (p = 0.002). Additionally, SLS & SCS in the HCM group were both significantly lower, before global strain affection (p < 0.001). Conclusion CMR-FT is a promising approach in analyzing impairment of global and segmental myocardium deformation in Egyptian patients with hypertrophic cardiomyopathy, non-invasively and quantitatively.

Characteristics and prognostic value of cardiac magnetic resonance strain analysis in patients with different phenotypes of heart failure.

Strain analysis of cardiac magnetic resonance imaging (CMR) is important for the prognosis of heart failure (HF). Herein, we aimed to identify the characteristics and prognostic value of strain analysis revealed by CMR in different HF phenotypes. Participants with HF, including HF with reduced ejection fraction, HF with mildly reduced ejection fraction, and HF with preserved ejection fraction, and controls were enrolled. The baseline information and clinical parameters of participants were collected, and echocardiography and CMR examination were performed. Three-dimensional strain analysis was performed in the left ventricle, right ventricle, left atrium, and right atrium using CMR. A multifactor Cox risk proportional model was established to assess the influencing factors of cardiovascular adverse events in patients with HF. During a median follow-up of 999 days (range: 616-1334), 20.6% of participants (73/354) experienced adverse events (HF readmission and/or cardiovascular death). Univariable Cox regression revealed that a 1% increase in left atrial global longitudinal strain (LAGLS) was associated with a hazard ratio (HR) of 1.21 [95% confidence interval (CI):1.15-1.28; P < 0.001]. Left ventricular global circumferential strain (LVGCS) (HR, 1.18; 95% CI: 1.12-1.24; P < 0.001), and left ventricular global longitudinal strain (LVGLS) (HR, 1.27; 95% CI: 1.20-1.36; P < 0.001) were also associated with HF hospitalizations and cardiovascular deaths. Among clinical variables, hypertension (HR, 2.11; 95% CI: 1.33-13.36; P = 0.002), cardiomyopathy (HR, 2.26; 95% CI: 1.42-3.60; P < 0.001) were associated with outcomes in univariable analysis. Multivariable analyses revealed that LAGLS (95% CI: 1.08-1.29; P < 0.001), LVGLS (95% CI:1.08-1.29; P < 0.001) and LVGCS (95% CI: 1.19-1.51; P < 0.001) were significantly associated with outcomes. Among clinical variables, hypertension (95% CI: 1.09-3.73; P < 0.025) remained a risk factor. CMR plays an obvious role in phenotyping HF. Strain analysis, particularly left atrial and left ventricular strain analysis (LAGLS, LVGLS, and LVGCS) has good value in predicting adverse outcome events.

Clinical service evaluation of the feasibility and reproducibility of novel artificial intelligence based-echocardiographic quantification of global longitudinal strain and left ventricular ejection fraction in trastuzumab-treated patients.

Cardiotoxicity is a potential prognostically important complication of certain chemotherapeutic agents that may result in preclinical or overt clinical heart failure. In some cases, chemotherapy must be withheld when left ventricular (LV) systolic function becomes significantly impaired, to protect cardiac function at the expense of a change in the oncological treatment plan, leading to associated changes in oncological prognosis. Accordingly, patients receiving potentially cardiotoxic chemotherapy undergo routine surveillance before, during and following completion of therapy, usually with transthoracic echocardiography (TTE). Recent advancements in AI-based cardiac imaging reveal areas of promise but key challenges remain. There are ongoing questions as to whether the ability of AI to detect subtle changes in individual patients is at a level equivalent to manual analysis. This raises the question as to whether AI-based left ventricular strain analysis could provide a potential solution to left ventricular systolic function analysis in a manner equivocal to or superior to conventional assessment, in a real-world clinical service. AI based automated analyses may represent a potential solution for addressing the pressure of increasing echocardiographic demands within limited service-capacity healthcare systems, in addition to facilitating more accurate diagnoses. This clinical service evaluation aims to establish whether AI-automated analysis compared to conventional methods (1) is a feasible method for assessing LV-GLS and LVEF, (2) yields moderate to good correlation between the two approaches, and (3) would lead to different clinical recommendations with serial surveillance in a real-world clinical population. We observed a moderate correlation (r = 0.541) in GLS between AI automated assessment compared to conventional methods. The LVEF quantification between methods demonstrated a strong correlation (r = 0.895). AI-generated GLS and LVEF values compared reasonably well with conventional methods, demonstrating a similar temporal pattern throughout echocardiographic surveillance. The apical-three chamber view demonstrated the lowest correlation (r = 0.423) and revealed to be least successful for acquisition of GLS and LVEF. Compared to conventional methodology, AI-automated analysis has a significantly lower feasibility rate, demonstrating a success rate of 14% (GLS) and 51% (LVEF).

The influence of symptom-to-reperfusion-time on left ventricular strain and extent of infarction in patients with STEMI: a 3-dimensional view on the wavefront phenomenon

Abstract Aims Data on the relationship between time-to-reperfusion and left ventricular (LV) function and infarct characteristics after ST-segment elevation myocardial infarction (STEMI) are inconsistent and not completely understood. Therefore, we examined the association between the symptom-to-reperfusion-time and cardiovascular magnetic resonance (CMR) derived global strain parameters and infarct extent in STEMI patients. Methods and results The study included 108 STEMI patients who underwent successful primary percutaneous coronary intervention (PPCI). Patients were categorized according to the median symptom-to-reperfusion-time: shorter (&amp;lt;160min, n=54) and longer times (&amp;gt;160min, n=54). CMR was performed 2-7 days after PPCI and at 1-month. CMR cine imaging was performed for functional assessment and late gadolinium enhancement (LGE) to evaluate infarct extent. Myocardial feature-tracking was used for global LV strain analysis. Mean transmural extent score was quantified per patient as the average of infarct percentages for all segments containing hyperenhanced tissue. Baseline clinical and angiographic characteristics were comparable between the groups. Patients with shorter reperfusion time had more favorable baseline and follow-up LV circumferential and radial strain (p=0.049, p=0.01, p=0.047, p&amp;lt;0.01, respectively), while LV longitudinal strain appeared comparable for both baseline and follow-up (p&amp;gt;0.05 for both, Figure 1). Mean transmural extent score at follow-up was lower in patients with shorter reperfusion time (p&amp;lt;0.01). In multivariable regression analysis including all 3 strain directions, baseline LV circumferential strain was independently associated with mean transmural extent score at follow-up (β=1.89, p&amp;lt;0.001). Conclusion In STEMI patients, time-to-reperfusion was significantly associated with smaller extent of infarction and better LV circumferential and radial strain but not with longitudinal strain. Moreover, infarct transmurality and residual LV circumferential strain are closely linked.Comparison of BL and FU global LV strainGraphical abstract

Functional significance of myocardial activity at 18F-FAPI PET/CT in hypertrophic cardiomyopathy identified by cardiac magnetic resonance feature-tracking strain analysis.

This study aimed to evaluate the functional significance of 18F-labeled fibroblast activation protein inhibitor (18F-FAPI) activity in hypertrophic cardiomyopathy (HCM) by comparison with cardiac magnetic resonance feature-tracking (CMR-FT) strain analysis. A total of 49 HCM patients were included in this study. Two independent control groups of healthy participants with a matched age and sex to the HCM patients were also enrolled. Left ventricular (LV) 18F-FAPI activity was analyzed for extent (FAPI%) and intensity (maximum target-to-background ratio, TBRmax). The CMR tissue characterization parameters of the LV included late gadolinium enhancement, native T1 value, and extracellular volume fraction. LV strain analysis was performed in radial, circumferential, and longitudinal peak strains (PS). Intense LV myocardial 18F-FAPI uptake was observed in HCM patients, whereas no obvious uptake was detected in healthy participants (median TBRmax, 9.1 vs. 1.2, p < 0.001). The strain parameters of HCM patients, compared with healthy participants, were significantly impaired (mean radial PS, 23.5 vs. 36.0, mean circumferential PS, -14.5 vs. -20.0, and mean longitudinal PS, -9.9 vs. -16.0, all p < 0.001). At segmental levels, there was a moderate correlation between 18F-FAPI activity and strain parameters. The number of positive 18F-FAPI uptake segments (n = 653) was higher than that of hypertrophic segments (n = 190) and positive CMR tissue characterization segments (n = 525) (all p < 0.001). In segments with negative CMR tissue characterization findings, the strain capacity of positive 18F-FAPI uptake segments was lower than that of negative 18F-FAPI uptake segments (median radial PS, 30.5 vs. 36.1, p = 0.026 and median circumferential PS, -18.4 vs. -19.7, p = 0.041). 18F-FAPI imaging can partially reflect the potential strain reduction in HCM patients. 18F-FAPI imaging detects more involved myocardium than CMR tissue characterization techniques, and the additionally identified myocardium has impaired strain capacity.

Changes in left ventricular strain and cardiac biomarkers in a six-year prospective follow-up after breast cancer radiotherapy

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Finnish public grant Aims Breast cancer radiotherapy (RT) can lead to slowly developing cardiac dysfunction and increased incidence of heart failure with preserved ejection fraction (HFpEF). In fact, the risk for HFpEF is shown to be 16-fold after chest radiotherapy. We aimed to study the changes in left ventricular strain six years after radiotherapy as well as changes in cardiac biomarkers during the follow-up. Methods Early left-sided breast cancer patients (n=31) were prospectively followed-up for six years after RT. Left ventricular strain analysis and pro-brain natriuretic peptide (proBNP) tests were performed at baseline, after RT and at three-year and six-year controls. In addition, cardiac magnetic resonance imaging (CMR) was performed at the six-year follow-up. The results were compared with cardiac RT doses. Results Global longitudinal strain (GLS) declined only modestly from baseline 17.9±4.1% to 17.6±2.7% at six-year control (p = 0.731) while apical regions showed significant decline from baseline 24.6±6.6% to 19.8±3.5% at six-year control (p&amp;lt;0.001). ProBNP increased from baseline 63.0 [37.0, 124.0] ng/l to 98.0 [50.0, 215.0] ng/l at six-year follow-up (p = 0.022). Patients with (n=14) and without (n=16) worsening of apical strain and increase in proBNP had maximal left ventricular radiation doses 46.9±4.8 Gy versus 40.1±12.9 Gy (p = 0.049), respectively. Lower values in CMR strain were concentrated in the apical regions with an association with regional RT doses. Each 1 Gy of regional radiation dose decreased local regional strain value in CMR by 0.356 % [95%CI; 0.244, 0.468] (p&amp;lt;0.001). Conclusions A significant increase in proBNP and a significant decrease in apical strain were observed after RT in six-year follow-up. A higher left ventricular maximal radiation dose was significantly associated with worsening in apical strain and proBNP. In addition, a worse regional strain values in CMR had a dose-dependent association with corresponding RT doses. These results indicate that even contemporary breast cancer RT induces progressive cardiac changes.

Machine learning model including left ventricular strain analysis for sudden cardiac death prediction in hypertrophic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Background The excess mortality in hypertrophic cardiomyopathy (HCM) patients is mainly attributed to the occurrence of sudden cardiac death (SCD). The prediction of ventricular arrhythmias remains challenging and could be improved. Purpose This study evaluated the added predictive value of a machine learning-based model combining clinical and conventional imaging parameters with information from left ventricular strain analysis to predict SCD in patients with HCM. Methods A total of 434 HCM patients (65% men, mean age 56 years) were retrospectively included from two referral centers from two different countries and followed longitudinally (mean duration 6 years). Strain parameters were automatically extracted from the left ventricle longitudinal strain segmental curves of each patient and included in a Ridge Regression model alongside conventional clinical and imaging data. The composite endpoint included sustained ventricular tachycardia, appropriate implantable cardioverter defibrillator therapy, aborted cardiac arrest, or sudden cardiac death. Results 34 patients (7.8%) met the endpoint with an incidence of ventricular arrhythmias of 0.9%/years. Among the 18 most discriminating parameters, 7 were derived from left ventricle longitudinal strain segmental curves analysis (figure 1). After n=200 rounds of cross-validation, the final model showed superior predictive performance compared to conventional models with a mean area under the curve (AUC) of 0.83 ± 0.8 compared with an AUC of 0.56 and 0.61 for the 2014 ESC risk score and the 2020 AHA/ACC model, respectively. Conclusion A machine learning model including automatically extracted left ventricular strain-derived parameters was superior in the prediction of sustained ventricular arrhythmias and SCD in patients with HCM compared to existing models. A machine learning model including left ventricle longitudinal strain analysis could improve SCD risk stratification in HCM patients.

Dynamic left atrial strain by dobutamine: Evidence for relationship with both left ventricular strain and atrioventricular volumetrics

Abstract Funding Acknowledgements Type of funding sources: None. Background Left atrial strain (LASR) by speckle-tracking echocardiography allows the assessment of LA function in each phase of the cardiac cycle. However, its determinants and its relation with left ventricular (LV) function have not yet been fully described. Moreover, a potential effect of the LV cavities volumes has been recently proposed. Purpose Purpose of the study was to assess the effect of LV functional indices to LASR in combination with LA and LV volumes both at rest (R) and during dobutamine stress echo (D). Methods We studied 58 consecutive patients (age 59/12, male/female 37/19) who underwent D without evidence of ischemia. Using 2-D speckle tracking in apical views, both LA and LV strain analysis was performed at R and D. The following parameters were estimated: LA volumes (max/min), LA emptying function (max-min/max), LA strain (SR: overall, reservoir, conduit, active), LV volumes (systole: LVSvol, diastole: LVDvol) stroke volume (SV), LV ejection fraction (LVEF), LV longitudinal strain (LVSR) and LA/LV max volume ratio (LA/LVvol). Results At R, among LA indices, LAtotalSR only was related to LVSR (r=0.31, p = 0.02). However, at D, LAcondSR, LAactive SR, LAtotalSR were related to LVSR (r=-0.25/0.36/0.3 respectively, all p&amp;lt;0.001). At R, LAEF, LAactiveSR and LAtotalSR were related with La/LVvol (r=-0.40/-0.40/0.45 respectively, all p&amp;lt;0.002). At D, LAEF, LAreservoirSR, LAactiveSR and LAtotalSR were related with La/LVvol (r=-0.39/-0.31/-0.31/-0.42 respectively, all p&amp;lt;0.001). For the determination of LAactiveSR at R, using stepwise multiple regression analysis including LVEF LVSR LVsv, LVDvol, La/LVvol, the greater contribution was provided by La/LVvol (initial R=0.41), with small improvement by LVSR (final R=0.50, p&amp;lt;0.001). In contrast, at D, the greater contribution for LAactiveSR was provided by LVSR (initial R=0.36) with some improvement by La/LVvol (final R=0.47 p&amp;lt;0.001). For the determination of LAtotalSR at R, the greatest contribution was provided by LA/LVvol (initial R=0.45) with improvement by LVSR (R=0.57) and finally by LVDvol (final R=0.64, p&amp;lt;0.001). For LAtotalSR at D, the greatest contribution was provided also by LA/LVvol (initial R=0.43) with further improvement by LVSR (final R=0.54, p&amp;lt;0.001). Conclusions LA strain indices are determined partially by LV strain both at rest and mainly during inotropic stimulation. However, they are further and beyond LV strain modulated by the ratio of LV and LA volumes, which play a key role for the overall LA strain both at R and during D. The LA active component is less dependent on volumes, and it is coherent to LV strain during inotropic modulation. Nonetheless, dynamic LA strain is of interest since it integrates LV/LA function, thus providing new insights for clinical application.

Three-dimensional left ventricular strain analysis in Fabry disease: correlation with heart failure severity, myocardial scar and impact on long-term prognosis

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Charles University Research program “Cooperatio - Cardiovascular Science”. Introduction Fabry disease (FD) is a multisystemic lysosomal storage disorder caused by a defect in the gene coding the alpha-galactosidase A enzyme. Cardiac involvement typically manifests as a phenocopy of hypertrophic cardiomyopathy. Three-dimensional echocardiography can analyze myocardial deformation of the left ventricle (LV) in both circumferential and longitudinal dimensions. Purpose We assessed 3D echocardiographic strain of the LV in FD patients in relation to heart failure severity, the presence of cardiovascular magnetic resonance (CMR) scar and long-term prognosis. Methods 3D echocardiography was feasible in 75/99 FD patients. Baseline natriuretic peptides and CMR late gadolinium enhancement were assessed together with long term outcome (death, heart failure decompensation or cardiovascular hospitalization) over a median follow-up of 3.1 years. Results The average age was 47 ± 14 years, 44% of patients were male and 51% expressed hypertrophy or concentric remodeling of the LV. Average LV ejection fraction (EF) was 65 ± 6%. A stronger correlation was observed for NTproBNP levels with 3D global longitudinal strain (GLS) (r = 0.49, p &amp;lt; 0.0001) than with 3D global circumferential strain (GCS) (r = 0.38, p &amp;lt; 0.001). LV EF by 3D weakly correlated with NTproBNP levels (r = 0.25, p = 0.036). Individuals with posterolateral scar on CMR had significantly lower local 3D circumferential strain at corresponding region (p = 0.008). 3D GLS was associated with long-term outcome (adjusted HR 0.84, CI 0.75, 0.95, p = 0.004) while 3D GCS was not (HR 0.94, CI 0.85 – 1.10, p = 0.284). 3D LV EF was not associated with long-term outcome. Conclusion 3D GLS is strongly associated with both heart failure severity measured as natriuretic peptides levels and long-term prognosis. Only borderline association of 3D GCS with HF severity and no association with prognosis was observed. Decreased local 3D CS reflects typical posterolateral scarring in FD. Where feasible, 3D-strain echocardiography can be used for comprehensive mechanical assessment of the LV in FD patients.

Three-dimensional echocardiographic left ventricular strain analysis in Fabry disease: correlation with heart failure severity, myocardial scar, and impact on long-term prognosis.

Fabry disease (FD) is a multisystemic lysosomal storage disorder caused by a defect in the alpha-galactosidase A gene that manifests as a phenocopy of hypertrophic cardiomyopathy. We assessed the echocardiographic 3D left ventricular (LV) strain of patients with FD in relation to heart failure severity using natriuretic peptides, the presence of a cardiovascular magnetic resonance (CMR) late gadolinium enhancement scar, and long-term prognosis. 3D echocardiography was feasible in 75/99 patients with FD [aged 47 ± 14 years, 44% males, LV ejection fraction (EF) 65 ± 6% and 51% with hypertrophy or concentric remodelling of the LV]. Long-term prognosis (death, heart failure decompensation, or cardiovascular hospitalization) was assessed over a median follow-up of 3.1 years. A stronger correlation was observed for N-terminal pro-brain natriuretic peptide levels with 3D LV global longitudinal strain (GLS, r = -0.49, P < 0.0001) than with 3D LV global circumferential strain (GCS, r = -0.38, P < 0.001) or 3D LVEF (r = -0.25, P = 0.036). Individuals with posterolateral scar on CMR had lower posterolateral 3D circumferential strain (CS; P = 0.009). 3D LV-GLS was associated with long-term prognosis [adjusted hazard ratio 0.85 (confidence interval 0.75-0.95), P = 0.004], while 3D LV-GCS and 3D LVEF were not (P = 0.284 and P = 0.324). 3D LV-GLS is associated with both heart failure severity measured by natriuretic peptide levels and long-term prognosis. Decreased posterolateral 3D CS reflects typical posterolateral scarring in FD. Where feasible, 3D-strain echocardiography can be used for a comprehensive mechanical assessment of the LV in patients with FD.

Machine learning model including left ventricular strain analysis for sudden cardiac death prediction in hypertrophic cardiomyopathy

The excess mortality in HCM patients is mainly attributed to the occurrence of SCD. The prediction of ventricular arrhythmias remains challenging and could be improved. This study evaluated the added predictive value of a machine learning-based model combining clinical and conventional imaging parameters with information from left ventricular strain analysis to predict sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM). A total of 434 HCM patients (65% men, mean age 56 years) were retrospectively included from two referral centers (Oslo University Hospital, Rennes University Hospital) and followed longitudinally (mean duration 6 years). Mechanical and temporal parameters were automatically extracted from the left ventricle longitudinal strain (LV-LS) segmental curves of each patient and included in a Ridge Regression model alongside conventional clinical and imaging data. The composite endpoint included sustained ventricular tachycardia, appropriate implantable cardioverter defibrillator therapy, aborted cardiac arrest, or sudden cardiac death (Fig. 1). Thirty-four patients (7.8%) met the endpoint with an incidence of ventricular arrhythmias of 0.9%/years. From a subset of 18 most discriminating parameters, including 7 derived from LV-LS, and after n = 200 rounds of cross-validation, the final model showed superior predictive performance compared to conventional models with a mean area under the curve (AUC) of 0.83 ± 0.8. A machine learning model including automatically extracted left ventricular strain-derived parameters was superior in the prediction of sustained ventricular arrhythmias and SCD in patients with HCM compared to existing models. Machine learning model including LV-LS analysis could improve SCD risk stratification in HCM patients (Fig. 1).

Cardiac cine with compressed sensing real-time imaging and retrospective motion correction for free-breathing assessment of left ventricular function and strain in clinical practice.

Free-breathing cardiac cine magnetic resonance imaging (MRI) comparable to the traditional breath-hold 2D segmented cine imaging (SegBH) is clinically required for cardiac function and strain analysis. This study is to assess the feasibility and accuracy of a free-breathing cardiac cine technique (RTCSCineMoCo) combined with highly accelerated real-time acquisition, compressed sensing, and fully automated non-rigid motion correction for left ventricular (LV) function and strain analysis, using SegBH as the reference and comparing with free-breathing single-shot real-time compressed sensing cine imaging (RTCSCine) without motion correction. A total of 67 patients scheduled for clinical cardiac MRI were included. Cine images were acquired using three techniques (SegBH, RTCSCineMoCo, RTCSCine) consecutively at 3.0 T. LV functional parameters, including ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volumes (SV), and LV mass (LVM) were measured and compared. Strain parameters including global radial (GRS), circumferential (GCS), and longitudinal (GLS) strain as well as corresponding time to peak strain (TPS) were computed by magnetic resonance (MR) feature tracking and compared. Subgroup analyses were performed according to heart rate (HR), left ventricular ejection fraction (LVEF), and etiology. All quantitative parameters of LV function and strain measured by RTCSCineMoCo (r≥0.766) and RTCSCine (r≥0.712) showed strong correlations with SegBH (all P<0.001). LV functional parameters were not statistically different between RTCSCineMoCo and SegBH (all P>0.05), but an overestimation of LV end-systolic volume (LVESV) and underestimation of LVEF and LVM were observed using RTCSCine (all P<0.001). GRS, GCS, and GLS by RTCSCineMoCo and RTCSCine were significantly different than those by SegBH (all P<0.05). All TPS values by RTCSCineMoCo showed no significant differences (all P>0.05) compared with SegBH, but TPS in longitudinal directions (TPSL) by RTCSCine was significantly different (P=0.011). There were no significant differences for GRS or GCS between RTCSCineMoCo and SegBH in patients with HR <70 bpm or LVEF <50%. GRS by RTCSCineMoCo showed similar results compared to SegBH in patients with pulmonary hypertension. RTCSCineMoCo is a promising method for robust free-breathing cardiac cine imaging, yielding more precise quantitative analytic results for LV function compared with RTCSCine. RTCSCineMoCo mildly underestimated GRS, GCS, and GLS, but showed smaller bias compared to RTCSCine in LV strain analysis.

The value of CMR Left ventricular strain analysis in evaluating ICM.

The purpose of this article is to investigate the value of cardiac magnetic resonance imaging (CMR) derived left ventricular strain parameters in evaluation of ischemic cardiomyopathy (ICM). Thirty-one ICM patients and nineteen non-cardiomyopathy (non-CM) patients who performed CMR examinations during the same period were selected for this retrospective study. The basic clinical data, CMR left ventricular function parameters, left ventricular strain parameters were compared among the left ventricular ejection fraction (LVEF) preserved ICM group, the LVEF impaired ICM group and the non-CM group. The differences of MyoGCS (-21.9 ± 1.9 vs. -18.9 ± 2.7 P<0.001), MyoGLS (-20.8 ± 2.3 vs. -17.0 ± 2.9 P<0.001) and EndoGLS (-22.2 ± 3.1 vs. -17.6 ± 3.7 P<0.001) between LVEF preserved ICM group and non-CM group were statistically significant, while the differences of left heart function parameters between the two groups were not statistically significant (P > 0.05). The left ventricular strain analysis can be used to assess cardiac functional and morphological alterations in ICM patients prior to changes of left ventricular function parameters, which has high clinical significance.

The role of cardiac magnetic resonance-based feature-tracking strain analysis in the differential diagnosis and prognostic assessment of patients with left ventricular hypertrophy

Abstract Background Cardiac magnetic resonance (CMR) examinations have an essential role in the diagnosis of myocardial diseases with left ventricular (LV) hypertrophy; however, limited data are available from CMR-based feature-tracking strain analysis in this patient population. The aim of our study was to investigate the differential diagnostic and prognostic importance of feature-tracking strain analysis in patients with LV hypertrophy caused by myocardial disease. Methods We investigated 404 patients who underwent CMR examination and were diagnosed with myocardial disease causing LV hypertrophy. Hypertrophic cardiomyopathy (HCM) was detected in 330 patients, cardiac amyloidosis (CA) in 46 patients, Fabry disease (FD) in 12 patients, and endomyocardial fibrosis (EMF) in 16 patients. LV strain analysis was performed with feature-tracking. Global longitudinal (GLS), circumferential (GCS) and radial (GRS) LV strain parameters were measured. Strain values for the six basal, six midventricular, and five apical segments were averaged to obtain regional longitudinal and circumferential strain values (basal LS, midventricular LS, apical LS, basal CS, midventricular CS, apical CS). The apex-to-base regional LS and CS ratios were calculated as apical LS/basal LS and apical CS/basal CS, respectively. To assess global dyssynchrony, mechanical dispersion (MD) was measured. The all-cause mortality of the patients was analyzed. Results In the differentiation of CA from HCM, GLS had the highest sensitivity with a cutoff of more than −23%, and basal LS and basal CS had the highest specificity with a cutoff of more than −16% and −38%, respectively (p&amp;lt;0.001). FD patients had the lowest longitudinal and circumferential MD values, meaning that compared to that of other patients with LV hypertrophy, global dyssynchrony is least pronounced in this patient population (p&amp;lt;0.01). EMF patients had impaired global and regional CS and the lowest apex-to-base CS and LS ratios. CA patients had the highest apex-to-base CS and LS ratios, suggestive of apical sparing (p&amp;lt;0.001). CA patients had the worst prognosis; the significant independent predictors of mortality were a diagnosis of CA, the LV stroke volume index and basal LS (p&amp;lt;0.01). Conclusions Myocardial diseases with left ventricular hypertrophy have remarkable differences in CMR-based strain characteristics which can be helpful in the differential diagnosis and provides incremental information on adverse outcomes. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Development and Innovation Fund of Hungary, Ministry for Innovation and Technology in Hungary

Global and regional left ventricular deformation evaluation with feature tracking in transthyretin cardiac amyloidosis. Comparison with echocardiographic findings

Abstract Background Diagnosis of cardiac amyloidosis (CA) is basically based on imaging techniques. Transthoracic echocardiography (TTE) is crucial to raise suspicion of this disease through detection of the classical features. An specific left ventricular (LV) deformation pattern with apical sparing (“cherry on top”) has been described on speckle tracking (ST) TTE. However, there is no data regarding the role of the LV global and regional analysis with the new tool feature tracking (FT) of cardiac magnetic resonance (CMR) in CA. Purpose Our aim is to analyze the concordance of LV deformation between ST-TTE and FT-CMR. Methods Consecutive patients with definitive diagnosis of transthyretin (TTR) CA, based on DPD scintigraphy, and imaging evaluation with TTE and CMR were retrospectively included. LV volumes and ejection were calculated from both TTE and CMR following the ongoing recommendations. Global and segmental longitudinal strain values were obtained from apical 2-, 3- and 4-chambers projections on TTE, while the same parameters were calculated on the same cine views of CMR using a dedicated software of FT analysis. Student t-test was used to compared mean measurements derived from both imaging techniques. Apical index was calculated as the ratio between apical and basal-mid longitudinal values. Moreover, agreement was established using Passing-Bablok regression analysis. Results 27 patients (80 years-old, 88% men) with definitive diagnosis of TTR CA from our tertiary hospital were included. Regarding echocardiographic findings, 80% showed concentric LV hypertrophy with low normal ejection fraction in the majority (52±10%). When longitudinal LV strain parameters were compared (Table 1), no differences were noted in global and apical values whereas basal and mid measurements were higher from CRM resulting in different apical indexes. Although 42% showed a typical “cherry on top” pattern in ST analysis, in only 18% of the FT apical sparing was detected. Consistently, decremental pattern was observed in 60% of TTE and in 20% of CMR. Concordance analysis with Passing-Bablok showed no constant or proportional differences, meaning both techniques were comparable. Conclusions Among patients with TTR CA there were no differences in global longitudinal LV strain analysis between ST-TTE and FT-CMR. Nevertheless, discordance in regional parameters resulted in a less frequent detection of apical sparing in CMR. Funding Acknowledgement Type of funding sources: None.

Comprehensive Cardiovascular Magnetic Resonance-Derived Myocardial Strain Analysis Provides Independent Prognostic Value in Acute Myocarditis.

Background Late gadolinium enhancement and left ventricular (LV) ejection fraction on cardiovascular magnetic resonance (CMR) are prognostic markers, but their predictive value for incident heart failure or life-threatening arrhythmias in acute myocarditis patients is limited. CMR-derived feature tracking provides a more sensitive analysis of myocardial function and may improve risk stratification in myocarditis. In this study, the prognostic value of LV, right ventricular, and left atrial strain in acute myocarditis patients is evaluated. Methods and Results In this multicenter retrospective study, patients with CMR-proven acute myocarditis were included. The primary end point was occurrence of major adverse cardiovascular events: all-cause mortality, heart transplantation, heart failure hospitalizations, and life threatening arrhythmias. LV global longitudinal strain, global circumferential strain and global radial strain, right ventricular-global longitudinal strain and left atrial strain were measured. Unadjusted and adjusted cox proportional hazard regression analysis were performed. In total, 162 CMR-proven myocarditis patients were included (41± 17 years, 75% men). Mean LV ejection fraction was 51± 12%, and 144 (89%) patients had presence of late gadolinium enhancement. Major adverse cardiovascular events occurred in 29 (18%) patients during a follow-up of 5.5 (2.2-8.3) years. All LV strain parameters were independent predictors of outcome beyond clinical features, LV ejection fraction and late gadolinium enhancement (LV-global longitudinal strain: hazard ratio [HR] 1.07, P=0.02; LV-global circumferential strain: HR 1.15, P=0.02; LV-global radial strain: HR 0.98, P=0.03), but right ventricular or left atrial strain did not predict outcome. Conclusions CMR-derived LV strain analysis provides independent prognostic value on top of clinical parameters, LV ejection fraction and late gadolinium enhancement in acute myocarditis patients, while left atrial and right ventricular strain seem to be of less importance.

Feasibility of one breath-hold cardiovascular magnetic resonance compressed sensing cine for left ventricular strain analysis.

ObjectiveTo investigate the feasibility of 3D left ventricular global and regional strain by using one breath-hold (BH) compressed sensing cine (CSC) protocol and determine the agreement between CSC and conventional cine (CC) protocols.MethodsA total of 30 volunteers were enrolled in this study. Cardiovascular magnetic resonance (CMR) images were acquired using a 1.436 T magnetic resonance imaging (MRI) system. The CSC protocols included one BH CSC and the shortest BH CSC protocols with different parameters and were only performed in short-axis (SA) view following CC protocols. Left ventricular (LV) end-diastole volume (EDV), end-systole volume (ESV), stroke volume (SV), and ejection fraction (EF) global and regional strain were calculated by CC, one BH CSC, and shortest BH CSC protocols. The intraclass correlation coefficient (ICC) and coefficient of variance (CV) of these parameters were used to determine the agreement between different acquisitions.ResultsThe agreement of all volumetric variables and EF between the CC protocol and one BH CSC protocol was excellent (ICC > 0.9). EDV, ESV, and SV between CC and shortest BH CSC protocols also had a remarkable coherence (ICC > 0.9). The agreement of 3D LV global strain assessment between CC protocol and one BH CSC protocol was good (ICC > 0.8). Most CVs of variables were also good (CV < 15%). ICCs of all variables were lower than 0.8. CVs of all parameters were higher than 15% except global longitudinal strain (GLS) between CC and shortest BH CSC protocols. The agreement of regional strain between CC and BH CSC protocols was heterogeneous (-0.2 < ICC < 0.7). Many variables of CVs were poor.ConclusionNotably, one BH CSC protocol can be used for 3D global strain analysis, along with a good correlation with the CC protocol. The regional strain should continue to be computed by the CC protocol due to poor agreement and a remarkable variation between the protocols. The shortest BH CSC protocol was insufficient to replace the CC protocol for 3D global and regional strain.