Conventional Cardiac Magnetic Resonance Research Articles

Optimal Threshold and Interpatient Variability in Left Atrial Ablation Scar Assessment by Dark-Blood LGE CMR.

Dark-blood late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) has better correlation with bipolar voltage (BiV) to define ablation scar in the left atrium (LA) compared to conventional bright-blood LGE CMR. This study sought to determine the optimal signal intensity threshold of dark-blood LGE CMR to identify LA ablation scar. In 54 patients scheduled for atrial fibrillation ablation, image intensity ratios (IIRs) were derived from preprocedural dark-blood LGE CMR. In 26 patients without previous ablation, the upper limit of normal was derived from the 95th and 98th percentiles of pooled IIR values. In 28 patients with previous atrial fibrillation ablation, BiV was compared with the corresponding IIR. Receiver-operating characteristics analyses were employed to determine the optimal IIR threshold (ie, the point with the smallest distance to the upper left corner of the receiver-operating characteristics) for LA ablation scar (BiV≤0.15mV). Upper limit of normal corresponded to IIR values 1.16 and 1.21, yielding low sensitivities of 0.32 and 0.09 to detect LA ablation scar. Receiver-operating characteristics analysis of IIR and BiV comparison achieved a median area under the curve of 0.77. Median optimal IIR threshold for LA ablation scar was 1.09, with an average sensitivity of 0.73, specificity of 0.75, and accuracy of 0.71. Median IIR thresholds of 1.00 and 1.10 corresponded to 80% sensitivity and 80% specificity, respectively. There was considerable interpatient variability: optimal IIR thresholds per patient ranged from 1.01 to 1.22. The optimal IIR threshold to identify LA ablation scar by dark-blood LGE CMR is 1.09. Because of interpatient variability, the investigators recommend using a lower (1.00) and upper (1.10) threshold to prevent over- or underestimation of ablation scar.

Systematic review and meta-analysis for the value of cardiac magnetic resonance strain to predict cardiac outcomes

Cardiac magnetic resonance (CMR) is the gold standard for the diagnostic classification and risk stratification in most patients with cardiac disorders. The aim of the present study was to investigate the ability of Strain-encoded MR (SENC) for the prediction of major adverse cardiovascular events (MACE). A systematic review and meta-analysis was performed according to the PRISMA Guidelines, including patients with or without cardiovascular disease and asymptomatic individuals. Myocardial strain by HARP were used as pulse sequences in 1.5 T scanners. Published literature in MEDLINE (PubMed) and Cochrane’s databases were explored before February 2023 for studies assessing the clinical utility of myocardial strain by Harmonic Phase Magnetic Resonance Imaging (HARP), Strain-encoded MR (SENC) or fast-SENC. In total, 8 clinical trials (4 studies conducted in asymptomatic individuals and 4 in patients with suspected or known cardiac disease) were included in this systematic review, while 3 studies were used for our meta-analysis, based on individual patient level data. Kaplan–Meier analysis and Cox proportional hazard models were used, testing the ability of myocardial strain by HARP and SENC/fast-SENC for the prediction of MACE. Strain enabled risk stratification in asymptomatic individuals, predicting MACE and the development of incident heart failure. Of 1332 patients who underwent clinically indicated CMR, including SENC or fast-SENC acquisitions, 19 patients died, 28 experienced non-fatal infarctions, 52 underwent coronary revascularization and 86 were hospitalized due to heart failure during median 22.4 (17.2–28.5) months of follow-up. SENC/fast-SENC, predicted both all-cause mortality and MACE with high accuracy (HR = 3.0, 95% CI = 1.2–7.6, p = 0.02 and HR = 4.1, 95% CI = 3.0–5.5, respectively, p < 0.001). Using hierarchical Cox-proportional hazard regression models, SENC/fast-SENC exhibited incremental value to clinical data and conventional CMR parameters. Reduced myocardial strain predicts of all-cause mortality and cardiac outcomes in symptomatic patients with a wide range of ischemic or non-ischemic cardiac diseases, whereas in asymptomatic individuals, reduced strain was a precursor of incident heart failure.

CMR Mapping: The 4th-Era Revolution in Cardiac Imaging.

Cardiac magnetic resonance (CMR) imaging has witnessed substantial progress with the advent of parametric mapping techniques, most notably T1 and T2 mapping. These advanced techniques provide valuable insights into a wide range of cardiac conditions, including ischemic heart disease, cardiomyopathies, inflammatory cardiomyopathies, heart valve disease, and athlete's heart. Mapping could be the first sign of myocardial injury and oftentimes precedes symptoms, changes in ejection fraction, and irreversible myocardial remodeling. The ability of parametric mapping to offer a quantitative assessment of myocardial tissue properties addresses the limitations of conventional CMR methods, which often rely on qualitative or semiquantitative data. However, challenges persist, especially in terms of standardization and reference value establishment, hindering the wider clinical adoption of parametric mapping. Future developments should prioritize the standardization of techniques to enhance their clinical applicability, ultimately optimizing patient care pathways and outcomes. In this review, we endeavor to provide insights into the potential contributions of CMR mapping techniques in enhancing the diagnostic processes across a range of cardiac conditions.

Role of cardiac magnetic resonance T1 mapping in comparison to T2* for cardiac iron overload assessment in transfusion-dependent thalassemia major patients

BackgroundCardiac complications are the leading cause of death in transfusion-dependent thalassemia major (TDT) patients due to increased cardiac iron overload (CIO), so this study’s purpose is to assess the diagnostic utility of cardiac magnetic resonance T1 mapping in correlation to T2* for the assessment of CIO in TDT patients. This prospective case–control study involved 55 TDT patients and 30 age- and gender-matched healthy controls. All the patients underwent assessment of myocardial T2*, and native T1 values by conventional cardiac magnetic resonance imaging, and native T1 mapping technique to assess the CIO. Comparison and association between T2*, and native T1 values among TDT patients were studied.ResultsA statistically significant difference is noted between control and patient groups in regard to mean T2* and native T1 values (P = 0.03 and 0.01, respectively). The mean native T1 value in TDT patients was lower than in the control group (992 ± 54 vs. 1234 ± 42), respectively, with a statistically significant P value of 0.04. The study evoked a statistically significant strong positive association, and correlation was noted between measured T2* and native T1 values (r = 0.84, P value = 0.001), while a moderate negative association was observed between native T1 values and S. ferritin levels (r = − 0.53, P value = 0.02).ConclusionsNative T1 mapping is a non-invasive promising complementary technique to T2* that helps to detect cardiac iron overload in TDT patients, as it is strongly associated with T2*. Also, native T1 value can differentiate mild, moderate, severe, and no cardiac iron overload.

Cardiac magnetic resonance hemodynamic force patterns in patients with ST-segment elevation myocardial infarction and dilated cardiomyopathy as compared to healthy controls: an observational study

Abstract Background Intraventricular Pressure Gradients (IVPG) reflect the driving force behind blood motion in and out of the left ventricle (LV). IVPG can be computed non-invasively using Cardiac Magnetic Resonance (CMR) cine imaging. It is unknown how IVPG components change as a consequence of ST-segment Elevation Myocardial Infarction (STEMI) and in non-ischemic Dilated Cardiomyopathy (DCM). Aims We aimed to assess if LV dysfunction of an ischemic and non-ischemic origin translates into reduced IVPG. The IVPG values were compared to conventional CMR markers of LV systolic function, to evaluate potential future applications. Methods This analysis of prospectively included cohorts included patients with DCM (n=40), anterior (n=20) or inferior STEMI (n=19) with an LV ejection fraction (EF) ≤ 52%, and healthy control subjects (n=13). LV ejection fraction was measured on the short-axis cine images. LV global longitudinal strain (GLS) and IVPG were measured in the long-axis cine images, using feature tracking software. Contours were drawn manually and the mitral and aortic valve orifice areas were measured. The dimensionless IVPG were measured in the longitudinal direction, using feature tracking combined with valve orifice measurements. IVPG consisted of the A, B, C, and D-wave, see Figure 1. IVPG values were compared between controls and diseased cohorts by the Mann Whitney U test. Results LVEF and LV-GLS were significantly impaired in all diseased groups. DCM and anterior STEMI patients had lower overall IVPG (15.1 [IQR 12.6-17.9] vs 9.4 [IQR 7.8-13.4], p=0.001 for DCM and 11.1 [IQR 8.7-13.0], p=0.002 for anterior STEMI). DCM and anterior STEMI patients had a significantly reduced systolic ejection A-wave (21.8 [IQR 19.1-27.2] in controls vs. 13.5 [IQR 10.3-19.1] in DCM, p&amp;lt;0.001, and 16.9 [IQR 10.8-20.6] in anterior STEMI, p=0.004). Secondly, patients with DCM and inferior STEMI have significantly dampened E-wave decelerative C-waves (8.1 [IQR 6.5-12.3] in controls, vs. 3.7 [IQR 2.4-5.5], p&amp;lt;0.001 in DCM, and 6.4 [IQR 4.3-7.8], p=0.04 in inferior STEMI), due to impaired passive ventricular filling. Conclusions IVPG values are altered in patients with myocardial dysfunction due to anterior and inferior STEMI to a lesser extent than in DCM patients. Conventional measures for systolic function (i.e. LV-GLS and LV ejection fraction) were lower in all diseased groups as well. On the other hand, IVPG is a promising measure to quantify diastolic LV function on the ventricular level.

Abstract 14687: Altered Left Ventricular Hemodynamic Forces as an Early Indicator of Disease Progression in Duchenne Muscular Dystrophy

Introduction: Duchenne muscular dystrophy (DMD) patients develop progressive cardiomyopathy. Cardiac magnetic resonance (CMR) imaging can identify global/regional dysfunction and myocardial fibrosis, although left ventricular (LV) biomechanics are not conventionally assessed. Thus, we investigated hemodynamic force (HDF), a novel measurement of the intraventricular pressure gradient, as potential biomarker for myocardial dysfunction in DMD. Methods: Prospective, multi-center study of DMD patients and age-matched controls. Feature-tracking (Qstrain, Medis) performed on short/long-axis cine to capture LV wall motion. Novel diffeomorphic mapping used to generate kinematic models and calculate HDF components (apical-basal, lateral-septal, anterior-posterior) throughout the cardiac cycle ( Figure 1A ). HDF was correlated to conventional CMR parameters. Results: Thirty-six DMD and 10 controls included with LV ejection fraction (LVEF) 51±6% vs 56±6% (p = 0.037). DMD patients with normal LVEF had altered HDF across multiple points in each axis compared to controls ( Figure 1B ). Twenty-one DMD patients (58%) with LVEF &lt; 55% had lower apical-basal (p = &lt; 0.001), lateral-septal (p = 0.001), and anterior-posterior (p = 0.005) root mean square (RMS) HDF compared to DMD with normal LVEF (Figure 1C) . All components of HDF correlated with LV volumetric/strain parameters ( Table 1 ). Conclusions: Cine-derived HDF are altered in DMD patients. Decreased systolic HDF and delay to peak diastolic HDF may be an early indicator of myocardial dysfunction compared to conventional CMR testing. Future studies will investigate HDF as a biomarker of disease progression.

Contrast-enhanced cardiac MRI is superior to non-contrast mapping to predict left ventricular remodeling at 6 months after acute myocardial infarction

ObjectivesParametric mapping constitutes a novel cardiac magnetic resonance (CMR) technique enabling quantitative assessment of pathologic alterations of left ventricular (LV) myocardium. This study aimed to investigate the clinical utility of mapping techniques with and without contrast agent compared to standard CMR to predict adverse LV remodeling following acute myocardial infarction (AMI).Materials and methodsA post hoc analysis was performed on sixty-four consecutively enrolled patients (57 ± 12 years, 54 men) with first-time reperfused AMI. Baseline CMR was obtained at 8 ± 5 days post-AMI, and follow-up CMR at 6 ± 1.4 months. T1/T2 mapping, T2-weighted, and late gadolinium enhancement (LGE) acquisitions were performed at baseline and cine imaging was used to determine adverse LV remodeling, defined as end-diastolic volume increase by 20% at 6 months.ResultsA total of 11 (17%) patients developed adverse LV remodeling. At baseline, patients with LV remodeling showed larger edema (30 ± 11 vs. 22 ± 10%LV; p < 0.05), infarct size (24 ± 11 vs. 14 ± 8%LV; p < 0.001), extracellular volume (ECVinfarct; 63 ± 12 vs. 47 ± 11%; p < 0.001), and native T2infarct (95 ± 16 vs. 78 ± 17 ms; p < 0.01). ECVinfarct and infarct size by LGE were the best predictors of LV remodeling with areas under the curve (AUCs) of 0.843 and 0.789, respectively (all p < 0.01). Native T1infarct had the lowest AUC of 0.549 (p = 0.668) and was inferior to edema size by T2-weighted imaging (AUC = 0.720; p < 0.05) and native T2infarct (AUC = 0.766; p < 0.01).ConclusionIn this study, ECVinfarct and infarct size by LGE were the best predictors for the development of LV remodeling within 6 months after AMI, with a better discriminative performance than non-contrast mapping CMR.Clinical relevance statementThis study demonstrates the predictive value of contrast-enhanced and non-contrast as well as conventional and novel CMR techniques for the development of LV remodeling following AMI, which might help define precise CMR endpoints in experimental and clinical myocardial infarction trials.Key Points• Multiparametric CMR provides insights into left ventricular remodeling at 6 months following an acute myocardial infarction.• Extracellular volume fraction and infarct size are the best predictors for adverse left ventricular remodeling.• Contrast-enhanced T1 mapping has a better predictive performance than non-contrast standard CMR and T1/T2 mapping.

Differentiation of acute non-ST elevation myocardial infarction and acute infarct-like myocarditis by visual pattern analysis: a head-to-head comparison of different cardiac MR techniques

ObjectivesParametric cardiac magnetic resonance (CMR) techniques have improved the diagnosis of pathologies. However, the primary tool for differentiating non-ST elevation myocardial infarction (NSTEMI) from myocarditis is still a visual assessment of conventional signal-intensity-based images. This study aimed at analyzing the ability of parametric compared to conventional techniques to visually differentiate ischemic from non-ischemic myocardial injury patterns.MethodsTwenty NSTEMI patients, twenty infarct-like myocarditis patients, and twenty controls were examined using cine, T2-weighted CMR (T2w) and late gadolinium enhancement (LGE) imaging and T1/T2 mapping on a 1.5 T scanner. CMR images were presented in random order to two experienced fully blinded observers, who had to assign them to three categories by a visual analysis: NSTEMI, myocarditis, or healthy.ResultsThe conventional approach (cine, T2w and LGE combined) had the best diagnostic accuracy with 92% (95%CI: 81–97) for NSTEMI and 86% (95%CI: 71–94) for myocarditis. The diagnostic accuracies using T1 maps were 88% (95%CI: 74–95) and 80% (95%CI: 62–91), 84% (95%CI: 67–93) and 74% (95%CI: 54–87) for LGE, and 83% (95%CI: 66–92) and 73% (95%CI: 53–87) for T2w. The accuracies for cine (72% (95%CI: 52–86) and 60% (95%CI: 38–78)) and T2 maps (62% (95%CI: 40–79) and 47% (95%CI: 28–68)) were significantly lower compared to the conventional approach (p < 0.001 and p < 0.0001).ConclusionsThe conventional approach provided a reliable visual discrimination between NSTEMI, myocarditis, and controls. The diagnostic accuracy of a visual pattern analysis of T1 maps was not significantly inferior, whereas the diagnostic accuracy of T2 maps was not sufficient in this context.Clinical relevance statementThe ability of parametric compared to conventional CMR techniques to visually differentiate ischemic from non-ischemic myocardial injury patterns can avoid potentially unnecessary invasive coronary angiography and help to shorten CMR protocols and to reduce the need of gadolinium contrast agents.Key Points•A visual differentiation of ischemic from non-ischemic patterns of myocardial injury is reliably achieved by a combination of conventional CMR techniques (cine, T2-weighted and LGE imaging).•There is no significant difference in accuracies between visual pattern analysis on native T1 maps without providing quantitative values and a conventional combined approach for differentiating non-ST elevation myocardial infarction, infarct-like myocarditis, and controls.•T2 maps do not provide a sufficient diagnostic accuracy for visual pattern analysis for differentiating non-ST elevation myocardial infarction, infarct-like myocarditis, and controls.

Incidence of myocarditis among patients recovered from COVID-19 infection identified using cardiac magnetic resonance imaging

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Coronavirus disease 2019 (COVID-19) has caused significant morbidity and mortality worldwide and has been associated with several cardiac complications including myocarditis. COVID-19 patients with myocardial injury have worse clinical outcomes than those without cardiac involvement. Hence, early detection of myocardial involvement in those who have recovered would be helpful in risk stratification of these patients. Locally, there has been no literature regarding cardiac involvement detected by cardiac magnetic resonance (CMR) imaging among COVID-19 patients. This study aims to report the incidence of patients who developed myocarditis among those who recovered from COVID-19 infection and who underwent CMR imaging in our institution. Methodology A single-center retrospective cohort study was performed in our institution. Consecutive patients from January 1, 2020, to December 31, 2021, who were initially referred for cardiac CMR examination due to cardiac symptoms and who met the following inclusion criteria 1) 19 years old and above; 2) with a history of a previously confirmed diagnosis of COVID-19 using reverse transcription-polymerase chain reaction (RT-PCR) swab test; 3) patients were considered recovered by the discharging criteria and 4) underwent CMR imaging for evaluation to rule out myocarditis in our institution. The primary outcome was determining the number of patients with positive and negative conventional MRI findings based on late gadolinium enhancement and edema. Results Fifty-four percent (54%) of patients had positive conventional MRI findings indicative of myocarditis (myocardial edema or late gadolinium presence). The most common co-morbid condition remains to be Hypertension (55%), followed by Diabetes Mellitus (17%). Dyspnea, palpitations and chest discomfort were the most commonly reported symptoms in 29 (54%), 24 (44%) and 21 (39%) patients, respectively. Twenty-nine patients (54%) were observed with increased T2 signal or positive LGE. Myocardial edema was found in 9 (31%) patients. Among them, 8 (57%) patients were observed with positive LGE. There was no significant difference of LV and RV systolic function among patients with positive and negative conventional CMR findings. Conclusion Myocarditis is one of the cardiovascular complications among patients who recovered from COVID-19, as demonstrated by our cardiac MRI study. Evaluation of the cardiac status of recovered COVID-19 patients needs to be closely monitored, and cardiac MRI may be a sensitive imaging tool to investigate any cardiac involvement further. This study provided local data on those with potential structural changes and cardiac complications aligned with the clinical history, which may be unique in our population after recovering from the disease. Further research with a larger sample size, risk factors, and the intervention to prevent disease progression may need more attention.

Abstract 12248: Decreased Left Ventricular Hemodynamic Forces As A Novel Biomarker Of Myocardial Dysfunction In Duchenne Muscular Dystrophy

Introduction: Patients with Duchenne muscular dystrophy (DMD) develop progressive cardiomyopathy. Cardiac magnetic resonance (CMR) imaging is used to identify global and regional function, as well as myocardial fibrosis in DMD. Unique left ventricular (LV) biomechanics cannot be assessed through conventional CMR techniques. Thus, we investigated hemodynamic force (HDF) through cine derived wall motion in the LV as a novel biomarker of myocardial dysfunction in DMD patients. Methods: This retrospective study consisted of CMR studies from DMD patients and age-matched controls. Feature-tracking (Qstrain, Medis) was performed on short-axis and long-axis cine imaging to capture LV wall motion. A novel technique based on diffeomorphic mapping was used to calculate three-dimensional LV kinematic models and HDF vectors throughout the cardiac cycle (Figure 1A). The apical-basal, lateral-septal, and anterior-posterior HDF vectors were correlated with global and regional functional parameters. Results: Eleven DMD and 11 controls were enrolled with LV EF 51 ± 6 vs 56 ± 6 (p = 0.09). DMD patients had decreased apical-basal and lateral-septal HDF across multiple points in the cardiac cycle compared to controls (Figure 1B). Six DMD patients with LV EF &lt; 55% were compared to 5 DMD patients with normal EF, demonstrating significant decrease in apical-basal systolic root mean square (RMS) HDF (p = 0.015), lateral-septal systolic RMS HDF (p = 0.009), anterior-posterior diastolic RMS HDF (p = 0.011), and magnitude systolic RMS HDF (p = 0.011) in patients with dysfunction. Absolute magnitude RMS HDF in all axes correlated with LV global longitudinal strain, LV global circumferential strain, and LV EF (r = 0.59 to 0.81, p &lt; 0.05). Conclusions: Cine derived HDF may be a more sensitive measure of LV dysfunction in DMD patients. Apical-basal HDF has potential as a novel biomarker for progression of disease.

Prognostic Value of Late Enhanced Cardiac Magnetic Resonance Imaging Derived Texture Features in Dilated Cardiomyopathy Patients With Severely Reduced Ejection Fractions.

Background: Late enhanced cardiac magnetic resonance (CMR) images of the left ventricular myocardium contain an enormous amount of information that could provide prognostic value beyond that of late gadolinium enhancements (LGEs). With computational postprocessing and analysis, the heterogeneities and variations of myocardial signal intensities can be interpreted and measured as texture features. This study aimed to evaluate the value of texture features extracted from late enhanced CMR images of the myocardium to predict adverse outcomes in patients with dilated cardiomyopathy (DCM) and severe systolic dysfunction.Methods: This single-center study retrospectively enrolled patients with DCM with severely reduced left ventricular ejection fractions (LVEFs < 35%). Texture features were extracted from enhanced late scanning images, and the presence and extent of LGEs were also measured. Patients were followed-up for clinical endpoints composed of all-cause deaths and cardiac transplantation. Cox proportional hazard regression and Kaplan–Meier analyses were used to evaluate the prognostic value of texture features and conventional CMR parameters with event-free survival.Results: A total of 114 patients (37 women, median age 47.5 years old) with severely impaired systolic function (median LVEF, 14.0%) were followed-up for a median of 504.5 days. Twenty-nine patients experienced endpoint events, 12 died, and 17 underwent cardiac transplantations. Three texture features from a gray-level co-occurrence matrix (GLCM) (GLCM_contrast, GLCM_difference average, and GLCM_difference entropy) showed good prognostic value for adverse events when analyzed using univariable Cox hazard ratio regression (p = 0.007, p = 0.011, and p = 0.007, retrospectively). When each of the three features was analyzed using a multivariable Cox regression model that included the clinical parameter (systolic blood pressure) and LGE extent, they were found to be independently associated with adverse outcomes.Conclusion: Texture features related LGE heterogeneities and variations (GLCM_contrast, GLCM_difference average, and GLCM_difference entropy) are novel markers for risk stratification toward adverse events in DCM patients with severe systolic dysfunction.

Relationship Between Quality of Life Indicators and Cardiac Status Indicators in Chemotherapy Patients.

AimWith the aim of improving personalized treatment of patients on chemotherapy, the objective of the study was to assess the degree of association between selected Quality of life (QoL) indicators and both clinical and imaging cardiac status indicators when detecting deterioration in QoL of these patients.MethodsIn a cohort clinical study in Hamburg, from August 2017 through October 2020, 59 cancer patients, aged 18-80 years, were evaluated before chemotherapy, and at several follow-ups, using EQ-5D and SF-36 QoL questionnaires, fast strain-encoded (fast-SENC) cardiac magnetic resonance (CMR), conventional CMR, and echocardiography, and further received a clinical and biomarker examination. Data was analyzed using survival analyses. A decline of more than 5% in each observed QoL metric value was defined as the observed event. Patient were separated into groups according to the presentation of cardiotoxicity as per its clinical definition, the establishment of the indication for cardioprotective therapy initiation, and by a worsening in the value of each observed imaging metric by more than 5% in the previous follow-up compared to the corresponding pre-chemotherapy baseline value.ResultsAmong clinical cardiac status indicators, the indication for cardioprotective therapy showed statistically good association with QoL scores (EQ-5D p=0.028; SF-36 physical component p=0.016; SF-36 mental component p=0.012). In terms of imaging metrics, the MyoHealth segmental myocardial strain score was the only one demonstrating consistently good QoL score association (EQ-5D p=0.005; SF-36 physical component p=0.056; SF-36 mental component p=0.002).ConclusionsEstablished fast-SENC CMR scores are capable of highlighting patients with reduced QoL, who require more frequent/optimal management.

Correlation between cardiac magnetic resonance feature tracking derived left ventricular strain and morphological characteristics of non-ischemic dilated cardiomyopathy at baseline and follow-up

Abstract Background Left ventricular (LV) strain from echocardiography is a known useful predictor of LVEF recovery in non-ischemic dilated cardiomyopathy (NIDCM). More recently, feature tracking (FT) has allowed LV myocardial deformation analysis using conventional cardiac magnetic resonance (CMR) cine sequences. Purpose Our aim is to establish the correlation between LV strain values from CMR-FT at diagnosis and morphological parameters at baseline and during follow-up. Methods Consecutive patients with NIDCM who underwent CMR were retrospectively collected. All the studies were performed in a 1.5 Tesla magnet following a standard acquisition protocol of conventional SSFP cine sequences in long and short axis. Global longitudinal, circumferential and radial strain (GLS, GCS and GRS, respectively) were obtained with a dedicated FT software. Correlation with CMR morphological parameters at baseline were evaluated. Likewise, in the cases with follow-up echocardiogram association between FT LV strain and evolution of morphofunctional variables was explored. Results CMR-FT strain analysis was performed in 98 patients (age 68±13 years, 72% males) with NIDCM. They showed severe LV dilatation (LVEDVi= 133.6±33.4 mL/m2) and systolic dysfunction (LVEF= 29.5±9.6%) at baseline. Myocardial fibrosis was detected in 38.8% of the patients with late gadolium enhancement (LGE) sequence. All the basal CMR morphological characteristics were significantly correlated with FT strain analysis (Table), even more markedly for GCS. However, there was no association of baseline morphofunctional parameters with LGE. An echocardiogram was performed in 85.7% of the patients during the follow-up (2.4 [1.8–3.4] years), with an LVEF &amp;gt;50% in the 25.5% of the cases. These patients with preserved LVEF in the evolution showed better GCS (−9 vs −7.1%; p=0.019) at baseline, with no differences in the other FT LV strain parameters. Despite less fibrosis in LGE (16.1% vs 37.7%; p=0.037), none of the baseline morphofunctional CMR parameters (LVEF, LVEDVi...) were associated with systolic function restoration. In multivariate analysis, GCS was the only independent predictor (OR 1.16; p=0.045) of LVEF recovery among imaging variables. Conclusions All the FT derived LV strain values were correlated with the degree of basal morphofunctional involvement in NIDCM. Furthermore, GCS emerged as an independent imaging predictor of LV systolic function restoration in our series. Funding Acknowledgement Type of funding sources: None. Table 1. Correlation between myocardial deformation values by feature tracking and morphofunctional variables in basal CMR.

Neural network-based left ventricle geometry prediction from CMR images with application in biomechanics

Combining biomechanical modelling of left ventricular (LV) function and dysfunction with cardiac magnetic resonance (CMR) imaging has the potential to improve the prognosis of patient-specific cardiovascular disease risks. Biomechanical studies of LV function in three dimensions usually rely on a computerized representation of the LV geometry based on finite element discretization, which is essential for numerically simulating in vivo cardiac dynamics. Detailed knowledge of the LV geometry is also relevant for various other clinical applications, such as assessing the LV cavity volume and wall thickness. Accurately and automatically reconstructing personalized LV geometries from conventional CMR images with minimal manual intervention is still a challenging task, which is a pre-requisite for any subsequent automated biomechanical analysis. We propose a deep learning-based automatic pipeline for predicting the three-dimensional LV geometry directly from routinely-available CMR cine images, without the need to manually annotate the ventricular wall. Our framework takes advantage of a low-dimensional representation of the high-dimensional LV geometry based on principal component analysis. We analyze how the inference of myocardial passive stiffness is affected by using our automatically generated LV geometries instead of manually generated ones. These insights will inform the development of statistical emulators of LV dynamics to avoid computationally expensive biomechanical simulations. Our proposed framework enables accurate LV geometry reconstruction, outperforming previous approaches by delivering a reconstruction error 50% lower than reported in the literature. We further demonstrate that for a nonlinear cardiac mechanics model, using our reconstructed LV geometries instead of manually extracted ones only moderately affects the inference of passive myocardial stiffness described by an anisotropic hyperelastic constitutive law. The developed methodological framework has the potential to make an important step towards personalized medicine by eliminating the need for time consuming and costly manual operations. In addition, our method automatically maps the CMR scan into a low-dimensional representation of the LV geometry, which constitutes an important stepping stone towards the development of an LV geometry-heterogeneous emulator.

Prognostic implications of left ventricular torsion by feature-tracking cardiac magnetic resonance in patients with ST-elevation myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): the National Key Research and Development Program of China OnBehalf Renji Hospital Affiliated to Medical College of Shanghai Jiaotong University Background The prognostic implications of left ventricular (LV) torsion on the long-term prognosis of patients with acute ST-elevation myocardial infarction (STEMI) is not clear. Methods We analyzed Cardiac Magnetic Resonance (CMR) images and followed up 420 first STEMI patients from the EARLY Assessment of MYOcardial Tissue Characteristics by CMR in STEMI (EARLY-MYO-CMR) registry (NCT03768453). These patients received timely primary percutaneous coronary intervention (PCI) within 12h and CMR examination within 1 week (median,5 days; range, 2-7 days) after infarction. Besides, CMR images of 40 normal people were enrolled as the control group. LV torsion, torsion rate and other conventional CMR indexes were measured. Ultrasound cardiogram examinations were performed in the acute phase and 1 year post-STEMI to assess LV remodeling (≥ 20% increase in LV end-diastolic volume). Primary end point was composite major adverse cardiac and cerebrovascular events (MACCEs) including cardiovascular death, re-infarction, re-hospitalization for heart failure and stroke. Secondary end points were the formation of LV aneurysm/thrombus in hospital as well as LV remodeling at 1 year post-STEMI. Results During follow-up (median: 52 months, inter-quartile range: 29–78 months), 80 patients developed MACCEs. Compared with normal people, patients with STEMI had more decreased LV torsion (P &amp;lt; 0.001) and torsion rate (P = 0.033). Patients who experienced MACCEs had more impaired LV torsion (P &amp;lt; 0.001) and torsion rate (P &amp;lt; 0.001) than those who didn’t. LV torsion ≤ 0.876 deg/cm in the acute phase of STEMI was an independent predictive factor of MACCE (P = 0.001) and LV remodeling (P = 0.001). Patients with impaired LV torsion were more likely to experience MACCEs (P &amp;lt; 0.001). The impairment of LV torsion was also associated with the higher incidence of LV aneurysm (P &amp;lt; 0.001) and thrombus (P = 0.006). The addition of LV torsion to a risk model comprising LV ejection fraction (LVEF), infarct size (IS), and microvascular obstruction (MVO) led to a net reclassification improvement (continuous NRI 0.499 [95% CI, 0.261–0.737]; P &amp;lt; 0.001). Hypertension (P = 0.047), tobacco use (P = 0.005), worse TIMI flow post-PCI (P &amp;lt; 0.001), more extensive IS (P &amp;lt; 0.001) / MVO size (P = 0.002) were associated with the impairment of LV torsion. Conclusions Compared with normal people, patients with STEMI had more decreased LV torsion and torsion rate. LV torsion ≤ 0.876 deg/cm in the acute phase was an independent predictive factor of MACCE and LV remodeling. The addition of LV torsion to a risk model comprising LVEF, LV-IS and LV-MVO significantly improved risk stratification of patients with STEMI .

Correlation of Myocardial Strain and Late Gadolinium Enhancement by Cardiac Magnetic Resonance After a First Anterior ST-Segment Elevation Myocardial Infarction.

Objectives: To investigate the correlation of cardiac magnetic resonance (CMR) feature-tracking with conventional CMR parameters in patients with a first anterior ST-segment elevation myocardial infarction (STEMI).Methods: This sub-analysis of OCTAMI (Optical Coherence Tomography Examination in Acute Myocardial Infarction) registry included 129 patients who finished a CMR examination 1 month after a first anterior STEMI. Cine images were applied to calculate both global and segmental left ventricular peak strain parameters. The patients were divided into two groups by left ventricular ejection fraction (LVEF) and compared with 42 healthy controls. Segmental late gadolinium enhancement (LGE) was graded according to LGE transmurality as follows: (1) >0 to ≤ 25%; (2) >25 to ≤ 50%; (3) >50 to ≤ 75%; (4) >75%. Left ventricle was divided into infarcted, adjacent, and remote regions to assess regional function.Results: Compared with controls, global radial (28.39 ± 5.08% vs. 38.54 ± 9.27%, p < 0.05), circumferential (−16.91 ± 2.11% vs. −20.77 ± 2.78%, p < 0.05), and longitudinal (−13.06 ± 2.15 vs. −15.52 ± 2.69, p < 0.05) strains were impaired in STEMI patients with normal LVEF (≥55%). Strain parameters were strongly associated with LGE (radial: r = 0.65; circumferential: r = 0.69; longitudinal: r = 0.61; all p < 0.05). A significant and stepwise impairment of global strains was observed in groups divided by LGE tertiles. Furthermore, segmental strain was different in various degrees of LGE transmurality especially for radial and circumferential strain. Strains of adjacent region were better than infarcted region in radial and circumferential directions and worse than remote region in all three directions.Conclusion: Global and regional strain could stratify different extent and transmurality of LGE, respectively. Although without LGE, adjacent region had impaired strains comparing with remote region.

Prognostic implications of cardiac magnetic resonance feature tracking derived multidirectional strain in patients with chronic aortic regurgitation.

Speckle-tracking echocardiography (STE) deformation parameters detect latent LV dysfunction in chronic aortic regurgitation (AR) and are associated with outcomes. The aim of the study was to evaluate cardiac magnetic resonance (CMR) feature tracking (FT) deformation parameters in asymptomatic patients with AR and implications in outcomes. Fifty-five patients with AR and 54 controls were included. Conventional functional CMR parameters, aortic regurgitant volume, and fraction were assessed. CMR-FT analysis was performed with a dedicated software. Clinical data was obtained from hospital records. A combined endpoint included all-cause mortality, cardiovascular mortality, aortic valve surgery, or cardiovascular hospital admission due to heart failure. Left ventricular (LV) mechanics is impaired in patients with significant AR. Significant differences were noted in global longitudinal strain (GLS) between controls and AR patients (- 19.1 ± 2.9% vs - 16.5 ± 3.2%, p < 0.001) and among AR severity groups (- 18.3 ± 3.1% vs - 16.2 ± 1.6% vs - 15 ± 3.5%; p = 0.02 for AR grades I-II, III, and IV). In univariate and multivariate analyses, circumferential strain (GCS) and global radial strain (GRS) but not GLS were associated with and increased risk of the end point with a HR of 1.26 (p = 0.016, 1.04-1.52) per 1% worsening for GCS and 0.90 (p = 0.012, 0.83-0.98) per 1% worsening for GRS. CMR-FT myocardial deformation parameters are impaired in patients with AR not meeting surgical criteria. GLS decreases early in the course of the disease and is a marker of AR severity while GCS and GRS worsen later but predict a bad prognosis, mainly the need of aortic valve surgery. • CMR feature tracking LV mechanic parameters may be reduced in significant chronic AR with normal EF. • LV mechanics, mainly global longitudinal strain, worsens as AR severity increases. • LV mechanics, specially global radial and circumferential strain, is associated with a worse prognosis in AR patients.

Differentiation between physiological sport adaptation and hypertrophic cardiomyopathy in highly trained athletes using cardiac magnetic resonance

Abstract Differentiation between hypertrophic cardiomyopathy (HCM) patients and healthy athletes (HA) is a common clinical conundrum. We aimed to analyze cardiac magnetic resonance (CMR) characteristics of HA, sedentary HCM and athletic HCM patients and to determine CMR parameters which can help to diagnose HCM in athletes. Male sedentary HCM patients with slightly elevated maximal end-diastolic wall thickness (EDWT 13–18 mm, n=40, 47.6±14.7y) and HA (n=30, 27.5±5.6y) were consecutively enrolled. Additionally, athletes with HCM were enrolled (n=16, 29.6±13.4 y), where a comprehensive investigation confirmed the diagnosis of HCM. We determined conventional CMR parameters (left ventricular (LV) ejection fraction (EF), end-diastolic (EDVi) and end-systolic volume index, mass index (Mi)), derived parameters such as EDWT/LVEDVi, LVM/LVEDV ratio and strain parameters such as global longitudinal (GLS), radial (GRS) and circumferential strain (GCS), SD of peak LS and CS using feature tracking. Presence of late gadolinium enhancement (LGE) was also determined. CMR parameters representing LV hypertrophy pattern or LV function were analyzed using a logistic regression to detect the best CMR parameters to predict HCM in athletes. To differentiate between HA and athletes with HCM optimal cut-off values for CMR parameters were calculated using receiver operating curve analysis. Comparing the three groups significant differences were found regarding conventional and derived CMR parameters and strain values. None of the HA showed LGE, 75% of athletic HCM and 82% of sedentary HCM patients showed LGE. The univariate regression model showed that LVEF, EDWT, EDWT/LVMi, LVM/LVEDV, GCS, GRS, SD of peak LS and CS are determinants of the diagnosis of HCM among athletes. Multivariate regression revealed that EDWT/LVMi and GCS are independent disease predictors in athletes (p&amp;lt;0.05). Cut-off value for GCS ≤−32.5 and for EDWT/LVEDVi &amp;gt;0.126 discriminate athletic HCM from HA with a sensitivity of 81.3 and 87.5% (AUC 0.93), and a specificity of 96.7 and 83.3% (AUC 0.95), respectively (Figure 1). CMR characteristics of sedentary and athletic HCM may differ, therefore establishing diagnostic parameters based on comparison between athletic HCM and HA is essential. CMR based strain and derived parameters may help to differentiate between physiological and pathological left ventricular hypertrophy in athletes. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Research, Development and Innovation Office of Hungary (NKFIA) and National Research, Development and Innovation Office (NFKIH) of Hungary.

Left Ventricular Flow Analysis in Atrial Fibrillation.

Atrial fibrillation (AF) is a global common disease which 33.5 million individuals suffer from. Conventional cardiac magnetic resonance and 4D flow magnetic resonance imaging have been used to study AF patients. We propose a left ventricular flow component analysis from 4D flow for AF detection. This method was applied to healthy controls and AF patients before catheter ablation. Retained inflow, delayed ejection, and residual volume had a significant difference between controls and the AF group as well as a conventional LV stroke volume parameter, and among them, residual volume was the strongest parameter to detect AF.

Cardiac Involvement in Patients Recovered From COVID-2019 Identified Using Magnetic Resonance Imaging

ObjectivesThis study evaluated cardiac involvement in patients recovered from coronavirus disease-2019 (COVID-19) using cardiac magnetic resonance (CMR). BackgroundMyocardial injury caused by COVID-19 was previously reported in hospitalized patients. It is unknown if there is sustained cardiac involvement after patients’ recovery from COVID-19. MethodsTwenty-six patients recovered from COVID-19 who reported cardiac symptoms and underwent CMR examinations were retrospectively included. CMR protocols consisted of conventional sequences (cine, T2-weighted imaging, and late gadolinium enhancement [LGE]) and quantitative mapping sequences (T1, T2, and extracellular volume [ECV] mapping). Edema ratio and LGE were assessed in post–COVID-19 patients. Cardiac function, native T1/T2, and ECV were quantitatively evaluated and compared with controls. ResultsFifteen patients (58%) had abnormal CMR findings on conventional CMR sequences: myocardial edema was found in 14 (54%) patients and LGE was found in 8 (31%) patients. Decreased right ventricle functional parameters including ejection fraction, cardiac index, and stroke volume/body surface area were found in patients with positive conventional CMR findings. Using quantitative mapping, global native T1, T2, and ECV were all found to be significantly elevated in patients with positive conventional CMR findings, compared with patients without positive findings and controls (median [interquartile range]: native T1 1,271 ms [1,243 to 1,298 ms] vs. 1,237 ms [1,216 to 1,262 ms] vs. 1,224 ms [1,217 to 1,245 ms]; mean ± SD: T2 42.7 ± 3.1 ms vs. 38.1 ms ± 2.4 vs. 39.1 ms ± 3.1; median [interquartile range]: 28.2% [24.8% to 36.2%] vs. 24.8% [23.1% to 25.4%] vs. 23.7% [22.2% to 25.2%]; p = 0.002; p < 0.001, and p = 0.002, respectively). ConclusionsCardiac involvement was found in a proportion of patients recovered from COVID-19. CMR manifestation included myocardial edema, fibrosis, and impaired right ventricle function. Attention should be paid to the possible myocardial involvement in patients recovered from COVID-19 with cardiac symptoms.