Cine Cardiovascular Magnetic Resonance Research Articles

Validation of Left Atrial Volume Correction for Single Plane Method on Four-Chamber Cine Cardiac MRI.

Left atrial (LA) assessment is an important marker of adverse cardiovascular outcomes. Cardiovascular magnetic resonance (CMR) accurately quantifies LA volume and function based on biplane long-axis imaging. We aimed to validate single-plane-derived LA indices against the biplane method to simplify the post-processing of cine CMR. In this study, 100 patients from Leeds Teaching Hospitals were used as the derivation cohort. Bias correction for the single plane method was applied and subsequently validated in 79 subjects. There were significant differences between the biplane and single plane mean LA maximum and minimum volumes and LA ejection fraction (EF) (all p < 0.01). After correcting for biases in the validation cohort, significant correlations in all LA indices were observed (0.89 to 0.98). The area under the curve (AUC) for the single plane to predict biplane cutoffs of LA maximum volume ≥ 112 mL was 0.97, LA minimum volume ≥ 44 mL was 0.99, LA stroke volume (SV) ≤ 21 mL was 1, and LA EF ≤ 46% was 1, (all p < 0.001). LA volumetric and functional assessment by the single plane method has a systematic bias compared to the biplane method. After bias correction, single plane LA volume and function are comparable to the biplane method.

Characteristics of pulmonary artery strain assessed by cardiovascular magnetic resonance imaging and associations with metabolomic pathways in human ageing.

Pulmonary artery (PA) strain is associated with structural and functional alterations of the vessel and is an independent predictor of cardiovascular events. The relationship of PA strain to metabolomics in participants without cardiovascular disease is unknown. In the current study, community-based older adults, without known cardiovascular disease, underwent simultaneous cine cardiovascular magnetic resonance (CMR) imaging, clinical examination, and serum sampling. PA global longitudinal strain (GLS) analysis was performed by tracking the change in distance from the PA bifurcation to the pulmonary annular centroid, using standard cine CMR images. Circulating metabolites were measured by cross-sectional targeted metabolomics analysis. Among n = 170 adults (mean age 71 ± 6.3 years old; 79 women), mean values of PA GLS were 16.2 ± 4.4%. PA GLS was significantly associated with age (β = -0.13, P = 0.017), heart rate (β = -0.08, P = 0.001), dyslipidemia (β = -2.37, P = 0.005), and cardiovascular risk factors (β = -2.49, P = 0.001). Alanine (β = -0.007, P = 0.01) and proline (β = -0.0009, P = 0.042) were significantly associated with PA GLS after adjustment for clinical risk factors. Medium and long-chain acylcarnitines were significantly associated with PA GLS (C12, P = 0.027; C12-OH/C10-DC, P = 0.018; C14:2, P = 0.036; C14:1, P = 0.006; C14, P = 0.006; C14-OH/C12-DC, P = 0.027; C16:3, P = 0.019; C16:2, P = 0.006; C16:1, P = 0.001; C16:2-OH, P = 0.016; C16:1-OH/C14:1-DC, P = 0.028; C18:1-OH/C16:1-DC, P = 0.032). By conventional CMR, PA GLS was associated with aging and vascular risk factors among a contemporary cohort of older adults. Metabolic pathways involved in PA stiffness may include gluconeogenesis, collagen synthesis, and fatty acid oxidation.

Manifold-based denoising for Ferumoxytol-enhanced 3D cardiac cine MRI.

The two-dimensional (2D) cine cardiovascular magnetic resonance (CMR) technique is the reference standard for assessing cardiac function. However, one challenge with 2D cine is that the acquisition time for the whole cine stack is long and requires multiple breath holds, which may not be feasible for pediatric or ill patients. Though single breath-hold multi-slice cine may address the issue, it can only acquire low-resolution images, and hence, affect the accuracy of cardiac function assessment. To address these challenges, a Ferumoxytol-enhanced, free breathing, isotropic high-resolution 3D cine technique was developed. The method produces high-contrast cine images with short acquisition times by using compressed sensing together with a manifold-based method for image denoising. This study included fifteen patients (9.1 $ \pm $ 5.6 yrs.) who were referred for clinical cardiovascular magnetic resonance imaging (MRI) with Ferumoxytol contrast and were prescribed the 3D cine sequence. The data was acquired on a 1.5T scanner. Statistical analysis shows that the manifold-based denoised 3D cine can accurately measure ventricular function with no significant differences when compared to the conventional 2D breath-hold (BH) cine. The multiplanar reconstructed images of the proposed 3D cine method are visually comparable to the golden standard 2D BH cine method in terms of clarity, contrast, and anatomical precision. The proposed method eliminated the need for breath holds, reduced scan times, enabled multiplanar reconstruction within an isotropic data set, and has the potential to be used as an effective tool to access cardiovascular conditions.

Kiosk 8R-FB-10 - Exploration of Geometric Deep Learning FBom 3D Cardiac Shape Models for the Classification of Cardiac Amyloid Sub-type FBom 2D Cine Cardiovascular Magnetic Resonance Imaging

Kiosk 8R-FB-10 - Exploration of Geometric Deep Learning FBom 3D Cardiac Shape Models for the Classification of Cardiac Amyloid Sub-type FBom 2D Cine Cardiovascular Magnetic Resonance Imaging

Prognostic value of global coronary flow reserve improvement after percutaneous coronary intervention in patients with chronic coronary syndrome

Abstract Background Impaired global coronary flow reserve (g-CFR) evaluated by phase-contrast cine cardiovascular magnetic resonance (PC-CMR) has been reported to be associated with worse outcomes in patients with cardiovascular disease. Purpose This study aimed to evaluate the prognostic value of g-CFR improvement evaluated by PC-CMR in patients with chronic coronary syndrome (CCS). Methods A total of 320 patients with CCS who underwent pre- and post-PCI PC-CMR measurements and stress perfusion CMR were followed-up to determine the predictors of major adverse cardiovascular events (MACE). The association between CMR variables including changes in G-CFR after PCI and MACE (cardiac death, nonfatal myocardial infarction, hospitalization for heart failure, or ischemic stroke) was investigated. Results G-CFR improvement was observed in 162 (50.6%) and MACE occurred in 26 (8.1%) during follow-up (2.5 year, 1.3-4.0). G-CFR improvement was significantly associated with lower pre-PCI G-CFR (p&amp;lt;0.001). Patients with MACE showed lower pre-PCI G-CFR, a high prevalence of post-PCI positive stress perfusion, non-G-CFR improvement. In Kaplan-Meier analysis, patients without G-CFR improvement were significantly associated with poor prognosis (log-rank χ2=5.8, P=0.018). After adjusting the presence of post-PCI positive stress perfusion, non-G-CFR improvement was an independent predictor of MACE (P=0.007). Conclusion In addition to the association between lower pre-PCI G-CFR and worse prognosis, G-CFR improvement after PCI may provide a novel insight into the prognosis after PCI in patients with CCS.Kaplan-Meier analysis

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

Non-contrast cine cardiovascular magnetic resonance-based radiomics nomogram for predicting microvascular obstruction after reperfusion in ST-segment elevation myocardial infarction.

This study aimed to develop and validate a cine cardiovascular magnetic resonance (CMR)-based radiomics nomogram model for predicting microvascular obstruction (MVO) following reperfusion in patients with ST-segment elevation myocardial infarction (STEMI). In total, 167 consecutive STEMI patients were retrospectively enrolled. The patients were randomly divided into training and validation cohorts with a ratio of 7:3. All patients were diagnosed with myocardial infarction with or without MVO based on late gadolinium enhancement imaging. Radiomics features were extracted from the cine CMR end-diastolic volume phase of the entire left ventricular myocardium (3D volume). The least absolute shrinkage and selection operator (LASSO) regression was employed to select the features that were most relevant to the MVO; these features were then used to calculate the radiomics score (Rad-score). A combined model was developed based on independent risk factors screened using multivariate regression analysis and visualized using a nomogram. Performance was assessed using receiver operating characteristic curve, calibration curve, and decision curve analysis (DCA). The univariate analysis of clinical features demonstrated that only cardiac troponin I (cTNI) was significantly associated with MVO. LASSO regression revealed that 12 radiomics features were strongly associated with MVO. Multivariate regression analysis indicated that cTNI and Rad-score were independent risk factors for MVO. The nomogram based on these two features achieved an area under the curve of 0.86 and 0.78 in the training and validation cohorts, respectively. Calibration curves and DCA indicated the clinical feasibility and utility of the nomogram. A CMR-based radiomics nomogram offers an effective means of predicting MVO without contrast agents and radiation, which could facilitate risk stratification of patients with STEMI after PCI for reperfusion.

Automated segmentation of 3D cine cardiovascular magnetic resonance imaging.

As the life expectancy of children with congenital heart disease (CHD) is rapidly increasing and the adult population with CHD is growing, there is an unmet need to improve clinical workflow and efficiency of analysis. Cardiovascular magnetic resonance (CMR) is a noninvasive imaging modality for monitoring patients with CHD. CMR exam is based on multiple breath-hold 2-dimensional (2D) cine acquisitions that should be precisely prescribed and is expert and institution dependent. Moreover, 2D cine images have relatively thick slices, which does not allow for isotropic delineation of ventricular structures. Thus, development of an isotropic 3D cine acquisition and automatic segmentation method is worthwhile to make CMR workflow straightforward and efficient, as the present work aims to establish. Ninety-nine patients with many types of CHD were imaged using a non-angulated 3D cine CMR sequence covering the whole-heart and great vessels. Automatic supervised and semi-supervised deep-learning-based methods were developed for whole-heart segmentation of 3D cine images to separately delineate the cardiac structures, including both atria, both ventricles, aorta, pulmonary arteries, and superior and inferior vena cavae. The segmentation results derived from the two methods were compared with the manual segmentation in terms of Dice score, a degree of overlap agreement, and atrial and ventricular volume measurements. The semi-supervised method resulted in a better overlap agreement with the manual segmentation than the supervised method for all 8 structures (Dice score 83.23 ± 16.76% vs. 77.98 ± 19.64%; P-value ≤0.001). The mean difference error in atrial and ventricular volumetric measurements between manual segmentation and semi-supervised method was lower (bias ≤ 5.2 ml) than the supervised method (bias ≤ 10.1 ml). The proposed semi-supervised method is capable of cardiac segmentation and chamber volume quantification in a CHD population with wide anatomical variability. It accurately delineates the heart chambers and great vessels and can be used to accurately calculate ventricular and atrial volumes throughout the cardiac cycle. Such a segmentation method can reduce inter- and intra- observer variability and make CMR exams more standardized and efficient.

Impact of symptom-to-reperfusion-time on transmural infarct extent and left ventricular strain in patients with ST-segment elevation myocardial infarction: a 3D view on the wavefront phenomenon.

We examined the association between the symptom-to-reperfusion-time and cardiovascular magnetic resonance (CMR)-derived global strain parameters and transmural infarct extent in ST-segment elevation myocardial infarction (STEMI) patients. 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 (<160 min, n = 54) and longer times (>160 min, 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 to evaluate transmural infarct extent. Myocardial feature-tracking was used for strain analysis. Groups were comparable in relation to incidence of LAD disease and pre- and post-PPCI thrombolysis in myocardial infarction (TIMI) flow grades. The mean transmural extent score at follow-up was lower in patients with shorter reperfusion time (P < 0.01). Both baseline and follow-up maximum transmural extent scores were smaller in patients with shorter reperfusion time (P = 0.03 for both). Patients with shorter reperfusion time had more favourable global left ventricular (LV) circumferential strain (baseline, P = 0.049; follow-up, P = 0.01) and radial strain (baseline, P = 0.047; follow-up, P < 0.01), whilst LV longitudinal strain appeared comparable for both baseline and follow-up (P > 0.05 for both). In multi-variable regression analysis including all three strain directions, baseline LV circumferential strain was independently associated with the mean transmural extent score at follow-up (β=1.89, P < 0.001). In STEMI patients, time-to-reperfusion was significantly associated with smaller transmural extent of infarction and better LV circumferential and radial strain. Moreover, infarct transmurality and residual LV circumferential strain are closely linked.

Deep learning-based prognostic model using non-enhanced cardiac cine MRI for outcome prediction in patients with heart failure.

To evaluate the performance of a deep learning-based multi-source model for survival prediction and risk stratification in patients with heart failure. Patients with heart failure with reduced ejection fraction (HFrEF) who underwent cardiac magnetic resonance between January 2015 and April 2020 were retrospectively included in this study. Baseline electronic health record data, including clinical demographic information, laboratory data, and electrocardiographic information, were collected. Short-axis non-contrast cine images of the whole heart were acquired to estimate the cardiac function parameters and the motion features of the left ventricle. Model accuracy was evaluated using the Harrell's concordance index. All patients were followed up for major adverse cardiac events (MACEs), and survival prediction was assessed using Kaplan-Meier curves. A total of 329 patients were evaluated (age 54 ± 14years; men, 254) in this study. During a median follow-up period of 1041days, 62 patients experienced MACEs and their median survival time was 495days. When compared with conventional Cox hazard prediction models, deep learning models showed better survival prediction performance. Multi-data denoising autoencoder (DAE) model reached the concordance index of 0.8546 (95% CI: 0.7902-0.8883). Furthermore, when divided into phenogroups, the multi-data DAE model could significantly discriminate between the survival outcomes of the high-risk and low-risk groups compared with other models (p < 0.001). The proposed deep learning (DL) model based on non-contrast cardiac cine magnetic resonance imaging could independently predict the outcome of patients with HFrEF and showed better prediction efficiency than conventional methods. The proposed multi-source deep learning model based on cardiac magnetic resonance enables survival prediction in patients with heart failure. • A multi-source deep learning model based on non-contrast cardiovascular magnetic resonance (CMR) cine images was built to make robust survival prediction in patients with heart failure. • The ground truth definition contains electronic health record data as well as DL-based motion data, and cardiac motion information is extracted by optical flow method from non-contrast CMR cine images. • The DL-based model exhibits better prognostic value and stratification performance when compared with conventional prediction models and could aid in the risk stratification in patients with HF.

Validating aortic stiffness parameters by cardiac magnetic resonance against mechanical testing of ex-vivo aortic aneurysms specimens

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III, Sociedad Española de Cardiología Background Aortic stiffness is a predictor of incident cardiovascular events and mortality in the general population (1). Cardiovascular magnetic resonance (CMR) imaging allow to compute a number of parameters, such as pulse wave velocity (PWV), distensibility (AD) and aortic longitudinal strain, theoretically related to aortic wall stiffness, but no formal validation has ever been reported. Purpose To test the correlation between aortic PWV, AD and longitudinal strain and aortic wall stiffness as assessed via ex-vivo mechanical testing of aortic specimens. Methods Patients undergoing ascending aorta (AAo) aneurysms resection underwent a CMR study which included bSSFP images and a 4D flow CMR of the thoracic aorta. At surgery 2 AAo specimens (each 15x5 mm, one oriented in the longitudinal and the other in circumferential aortic direction) were extracted, maintaining a record of their in-vivo position and orientation, and frozen. Specimens were tested under control for extension force (I5558, INSTRON) and elongation was quantifies by laser video extensometer (2663–281, INSTRON). The Young's modulus (E), i.e. tangent of the stress-strain curve, was quantified at the patient’s diastolic pressure during CMR (2). AAo PWV was extracted from 4D flow CMR study and the product of Eh (h being wall thickness) was computed via the Moens-Korteweg equation using the mean AAo diameter(3,4). AD was quantified from cine CMR at the pulmonary artery level using ARTFUN software (INSERM U678, France) while AAo longitudinal strain was assessed as mean deformation of the AAo by tracking the aortic root during the cardiac cycle (5). Results Twenty patients were included: age 52.5 [37.3 – 71.0] years, 13 (65%) male, BSA 1.94 [1.74 – 1.94] m2. Most of patients had AAo aneurysms of degenerative origin and a tricuspid aortic valve, while 2 patients had a bicuspid aortic valve, and 9 patients had connective tissue disorders. Due to missing data, one AD a two PWV could not have been computed while the specimen in circumferential direction of a patient could not be tested. AAo PWV, Eh and AD were strongly associated with circumferential elastic modulus at diastolic blood pressure (R = 0.652, R = 0.602 and R = -0.502, respectively) (Figure 1). Strong association was also obtained between AAo longitudinal strain and longitudinal elastic modulus at diastolic blood pressure (R = -0.513). Conclusion Pulse wave velocity and the derived Eh product, aortic distensibility and aortic longitudinal strain as non-invasively assessed by CMR are reliable representation of aortic wall stiffness.

Complementary prognostic value of stress perfusion imaging and global coronary flow reserve derived from cardiovascular magnetic resonance: a long-term cohort study

BackgroundPhase-contrast cine cardiovascular magnetic resonance (CMR) quantifies global coronary flow reserve (CFR) by measuring blood flow in the coronary sinus (CS), allowing assessment of the entire coronary circulation. However, the complementary prognostic value of stress perfusion CMR and global CFR in long-term follow-up has yet to be investigated. This study aimed to investigate the complementary prognostic value of stress myocardial perfusion imaging and global CFR derived from CMR in patients with suspected or known coronary artery disease (CAD) during long-term follow-up. MethodsParticipants comprised 933 patients with suspected or known CAD who underwent comprehensive CMR. Major adverse cardiac events (MACE) comprised cardiac death, non-fatal myocardial infarction, unstable angina, hospitalization for heart failure, stroke, ventricular arrhythmia, and late revascularization. ResultsDuring follow-up (median, 5.3 years), there were 223 MACE. Kaplan–Meier curve analysis revealed a significant difference in event-free survival among tertile groups for global CFR (log-rank, p < 0.001) and between patients with and without ischemia (p < 0.001). The combination of stress perfusion CMR and global CFR enhanced risk stratification (p < 0.001 for overall), and prognoses were comparable between the subgroup with ischemia and no impaired CFR and the subgroup with no ischemia and impaired CFR (p = 0.731). Multivariate Cox proportional hazard regression analysis showed that impaired CFR remained a significant predictor for MACE (hazard ratio, 1.6; p = 0.002) when adjusted for coronary risk factors and CMR predictors, including ischemia. The addition of impaired CFR to coronary risk factors and ischemia significantly increased the global chi-square value from 88 to 109 (p < 0.001). Continuous net reclassification improvement and integrated discrimination with the addition of global CFR to coronary risk factors plus ischemia improved to 0.352 (p < 0.001) and 0.017 (p < 0.001), respectively. ConclusionsDuring long-term follow-up, stress perfusion CMR and global CFR derived from CS flow measurement provided complementary prognostic value for prediction of cardiovascular events. Microvascular dysfunction or diffuse atherosclerosis as shown by impaired global CFR may play a role as important as that of ischemia due to epicardial coronary stenosis in the risk stratification of CAD patients.

Coronary flow reserve evaluated by phase-contrast cine cardiovascular magnetic resonance imaging of coronary sinus: a meta-analysis

BackgroundPhase-contrast cine cardiovascular magnetic resonance (CMR) of the coronary sinus has emerged as a non-invasive method for measuring coronary sinus blood flow and coronary flow reserve (CFR). However, its clinical utility has not yet been established. Here we performed a meta-analysis to clarify the clinical value of CMR-derived CFR in various cardiovascular diseases. MethodsAn electronic database search was performed of PubMed, Web of Science Core Collection, Cochrane Advanced Search, and EMBASE. We compared the CMR-derived CFR of various cardiovascular diseases (stable coronary artery disease [CAD], hypertrophic cardiomyopathy [HCM], dilated cardiomyopathy [DCM]) and control subjects. We assessed the prognostic value of CMR-derived CFR for predicting major adverse cardiac events (MACE) in patients with stable CAD. ResultsA total of 47 eligible studies were identified. The pooled CFR from our meta-analysis was 3.48 (95% confidence interval [CI], 2.98–3.98) in control subjects, 2.50 (95% CI, 2.38–2.61) in stable CAD, 2.01 (95% CI, 1.70–2.32) in cardiomyopathies (HCM and DCM). The meta-analysis showed that CFR was significantly reduced in stable CAD (mean difference [MD] = −1.48; 95% CI, −1.78 to −1.17; p < 0.001; I2 = 0%; p for heterogeneity = 0.33), HCM (MD = −1.20; 95% CI, −1.63 to −0.77; p < 0.001; I2 = 0%; p for heterogeneity = 0.49), and DCM (MD = −1.53; 95% CI, −1.93 to −1.13; p < 0.001; I2 = 0%; p for heterogeneity = 0.45). CMR-derived CFR was an independent predictor of MACE for patients with stable CAD (hazard ratio = 0.52 per unit increase; 95% CI, 0.37–0.73; p < 0.001; I2 = 84%, p for heterogeneity < 0.001). ConclusionsCMR-derived CFR was significantly decreased in cardiovascular diseases, and a decreased CFR was associated with a higher occurrence of MACE in patients with stable CAD. These results suggest that CMR-derived CFR has potential for the pathological evaluation of stable CAD, cardiomyopathy, and risk stratification in CAD.

Localized strain characterization of cardiomyopathy in Duchenne muscular dystrophy using novel 4D kinematic analysis of cine cardiovascular magnetic resonance

BackgroundCardiomyopathy (CMP) is the most common cause of mortality in Duchenne muscular dystrophy (DMD), though the age of onset and clinical progression vary. We applied a novel 4D (3D + time) strain analysis method using cine cardiovascular magnetic resonance (CMR) imaging data to determine if localized strain metrics derived from 4D image analysis would be sensitive and specific for characterizing DMD CMP. MethodsWe analyzed short-axis cine CMR image stacks from 43 DMD patients (median age: 12.23 yrs [10.6–16.5]; [interquartile range]) and 25 male healthy controls (median age: 16.2 yrs [13.3–20.7]). A subset of 25 male DMD patients age-matched to the controls (median age: 15.7 yrs [14.0-17.8]) was used for comparative metrics. CMR images were compiled into 4D sequences for feature-tracking strain analysis using custom-built software. Unpaired t-test and receiver operator characteristic area under the curve (AUC) analysis were used to determine statistical significance. Spearman's rho was used to determine correlation. ResultsDMD patients had a range of CMP severity: 15 (35% of total) had left ventricular ejection fraction (LVEF) > 55% with no findings of myocardial late gadolinium enhancement (LGE), 15 (35%) had findings of LGE with LVEF > 55% and 13 (30%) had LGE with LVEF < 55%. The magnitude of the peak basal circumferential strain, basal radial strain, and basal surface area strain were all significantly decreased in DMD patients relative to healthy controls (p < 0.001) with AUC values of 0.80, 0.89, and 0.84 respectively for peak strain and 0.96, 0.91, and 0.98 respectively for systolic strain rate. Peak basal radial strain, basal radial systolic strain rate, and basal circumferential systolic strain rate magnitude values were also significantly decreased in mild CMP (No LGE, LVEF > 55%) compared to a healthy control group (p< 0.001 for all). Surface area strain significantly correlated with LVEF and extracellular volume (ECV) respectively in the basal (rho = − 0.45, 0.40), mid (rho = − 0.46, 0.46), and apical (rho = − 0.42, 0.47) regions. ConclusionStrain analysis of 3D cine CMR images in DMD CMP patients generates localized kinematic parameters that strongly differentiate disease from control and correlate with LVEF and ECV.

The use of dedicated long-axis views focused on the left atrium improves the accuracy of left atrial volumes and emptying fraction measured by cardiovascular magnetic resonance

BackgroundThe use of apical views focused on the left atrium (LA) has improved the accuracy of LA volume evaluation by two-dimensional (2D) echocardiography. However, routine cardiovascular magnetic resonance (CMR) evaluation of LA volumes still uses standard 2- and 4-chamber cine images focused on the left ventricle (LV). To investigate the potential of LA-focused CMR cine images, we compared LA maximuml (LAVmax) and minimum (LAVmin) volumes, and emptying fraction (LAEF), calculated on both standard and LA-focused long-axis cine images, with LA volumes and LAEF obtained by short-axis cine stacks covering the LA. LA strain was also calculated and compared between standard and LA-focused images. MethodsLA volumes and LAEF were obtained from 108 consecutive patients by applying the biplane area-length algorithm to both standard and LA-focused 2- and 4-chamber cine images. Manual segmentation of a short-axis cine stack covering the LA was used as the reference method. In addition, LA strain reservoir (εs), conduit (εe) and booster pump (εa) were calculated using CMR feature-tracking. ResultsCompared to the reference method, the standard approach significantly underestimated LA volumes (LAVmax: bias − 13 ml; LOA = + 11, − 37 ml; LAVmax i: bias − 7 ml/m2; LOA = + 7, − 21 ml/m2; LAVmin; bias − 10 ml, LOA: + 9, − 28 ml; LAVmin i: bias − 5 ml/m2, LOA: + 5, − 16 ml/m2), and overestimated LA-EF (bias 5%, LOA: + 23, − 14%). Conversely, LA volumes (LAVmax: bias 0 ml; LOA: + 10, − 10 ml; LAVmax i: bias 0 ml/m2; LOA: + 5, − 6 ml/m2; LAVmin: bias − 2 ml; LOA: + 7, − 10 ml; LAVmin i: bias − 1 ml/m2; LOA: + 3, − 5 ml/m2) and LAEF (bias 2%, LOA: + 11, − 7%) by LA-focused cine images were similar to those measured using the reference method. LA volumes by LA-focused images were obtained faster than using the reference method (1.2 vs 4.5 min, p < 0.001). LA strain (εs: bias 7%, LOA = 25, − 11%; εe: bias 4%, LOA = 15, − 8%; εa: bias 3%, LOA = 14, − 8%) was significantly higher in standard vs. LA-focused images (p < 0.001). ConclusionLA volumes and LAEF measured using dedicated LA-focused long-axis cine images are more accurate than using standard LV-focused cine images. Moreover, LA strain is significantly lower in LA-focused vs. standard images.

Aortic Distensibility Measured by Automated Analysis of Magnetic Resonance Imaging Predicts Adverse Cardiovascular Events in UK Biobank.

Background Automated analysis of cardiovascular magnetic resonance images provides the potential to assess aortic distensibility in large populations. The aim of this study was to compare the prediction of cardiovascular events by automated cardiovascular magnetic resonance with those of other simple measures of aortic stiffness suitable for population screening. Methods and Results Aortic distensibility was measured from automated segmentation of aortic cine cardiovascular magnetic resonance using artificial intelligence in 8435 participants. The associations of distensibility, brachial pulse pressure, and stiffness index (obtained by finger photoplethysmography) with conventional risk factors was examined by multivariable regression and incident cardiovascular events by Cox proportional-hazards regression. Mean (±SD) distensibility values for men and women were 1.77±1.15 and 2.10±1.45 (P<0.0001) 10-3 mm Hg-1, respectively. There was a good correlation between automatically and manually obtained systolic and diastolic aortic areas (r=0.980 and r=0.985, respectively). In regression analysis, distensibility associated with age, mean arterial pressure, heart rate, weight, and plasma glucose but not male sex, cholesterol or current smoking. During an average follow-up of 2.8±1.3 years, 86 participants experienced cardiovascular events 6 of whom died. Higher distensibility was associated with reduced risk of cardiovascular events (adjusted hazard ratio [HR], 0.61 per log unit of distensibility; P=0.016). There was no evidence of an association between pulse pressure (adjusted HR 1.00; P=0.715) or stiffness index (adjusted HR, 1.02; P=0.535) and risk of cardiovascular events. Conclusions Automated cardiovascular magnetic resonance-derived aortic distensibility may be incorporated into routine clinical imaging. It shows a similar association to cardiovascular risk factors as other measures of arterial stiffness and predicts new-onset cardiovascular events, making it a useful tool for the measurement of vascular aging and associated cardiovascular risk.

Abstract 12664: Comprehensive Histological Analysis of Endomyocardial Biopsy and T1 Mapping for Predicting Left Ventricular Reverse Remodeling in Patients with Recent-Onset Dilated Cardiomyopathy

Background: Cardiomyocyte injury is a key pathological pathway in the progression of heart failure that predicts a poor prognosis; therefore, combined assessment of myocardial fibrosis and cardiomyocyte DNA damage from endomyocardial biopsy (EMB) samples may be of great importance. Meanwhile, cardiovascular magnetic resonance (CMR) native T1 reflects a composite of both intra- and extracellular compartments in the whole myocardium. We sought to assess the performance of native T1 mapping and EMB results to predict left ventricular reverse remodeling (LVRR) in recent-onset dilated cardiomyopathy (DCM). Methods: A total of 29 patients with DCM underwent cine CMR and triple-slice T1 mapping using the MOLLI sequence at 3T, and EMB before receiving guideline-directed medical therapy. Poly ADP-ribose (PAR) nuclear and sirius-red staining were used for quantification of DNA damage and collagen volume fraction (CVF), respectively. LVRR was defined as an increase in LV ejection fraction of ≥10% to the final value of &gt;35%, accompanied by a decrease in LV end-diastolic volume ≥10% at the follow-up CMR. Results: Fifteen patients (52%) achieved LVRR. The mean native T1, histological CVF, and proportion of PAR-positive nuclei were 1376 ± 55 ms, 0.13 ± 0.05, 25 ± 15%, respectively. Native T1 correlated well with CVF (p=0.004) and trended to be higher in DCM patients with increased DNA damage (p=0.17). There was no significant association between CVF and %PAR-positive nuclei. Native T1 &lt;1400 ms provided 86% sensitivity and 67% specificity, with the C-statistic of 0.82 (95% CI 0.67-0.98) for predicting LVRR. By contrast, C-statistic of %PAR nuclei, CVF, and combined assessment of %PAR nuclei and CVF were 0.59, 0.61 and 0.66, respectively. Conclusion: CMR T1 mapping may be a promising strategy for noninvasive biopsy of the whole heart and provide a better prediction of LVRR in recent-onset DCM than comprehensive histological analysis of EMB.

Prenatal diagnosis of fetal ectopia cordis by fetal cardiovascular magnetic resonance imaging.

The purpose of this retrospective study was to report our cases of fetal ectopia cordis (EC) and to evaluate the utility of fetal cardiovascular magnetic resonance imaging (MRI) for the diagnosis of this rare anomaly. This retrospective study included 11 fetuses with EC. The multiplane steady-state free precession (SSFP) sequence, single-shot turbo spin-echo sequence and non-gated SSFP cine cardiovascular magnetic resonance were used to evaluate the fetal heart and abdomen. The 11 fetal cases with EC were examined by fetal cardiovascular MRI and confirmed by postnatal or post-mortem findings. Of these 11 cases, two were isolated thoracic EC, six had pentalogy of Cantrell, and three had an omphalocele and EC. Among all 11 fetuses, nine were associated with congenital heart defects. In four cases, fetal MRI added additional information compared to fetal ultrasound, however, in two cases, fetal MRI missed the diagnosis of a ventricular septal defect noted by echocardiography. Fetal MRI combined with prenatal echocardiography can improve the accuracy of the prenatal diagnosis of EC.

Prognostic implications of trabecular complexity measured by fractal analysis in left ventricular noncompaction

Abstract Introduction Left ventricular non compaction (LVNC) is a heterogeneous entity characterized by prominent LV trabeculae. Fractal analysis, a semi-automatic method to quantify the degree of hypertrabeculation, has been described as a diagnostic criterion for LVNC. However, the prognostic implications of fractal analysis have not been investigated. Purpose Therefore, the aim of our study was to identify the relationship between the trabecular complexity measured by fractal analysis and the occurrence of cardiovascular events in LVNC patients. Methods We conducted a retrospective longitudinal multicenter cohort study of consecutive patients fulfilling LVNC criteria by cardiovascular magnetic resonance (CMR). The endpoints were heart failure (HF), ventricular arrythmias (VA), systemic embolism (SE) and all-cause mortality. Fractal analysis was performed on short-axis CMR cine images using CVI 42 software. The cohort was divided in two groups according to the maximal apical fractal dimension (FD). Results A total of 291 patients were included: age was 44±19 years and 56% were female. LV ejection fraction (LVEF) was 47% ± 14% and 26 patients (9%) presented late gadolinium enhancement (LGE). Mean global FD was 1.29±0.06 and maximal apical FD was 1.39±0.09. Baseline characteristics of patients with maximal apical FD 1.39 and 1.39, including functional LV parameters, were comparable (Table 1). After 3.8±2.5 years of follow-up, 37 patients (12.8%) presented HF, 30 (10.4%) had VA, SE occurred in 3 (1%) and 3 patients (1%) died. Maximal apical FD was not associated with the risk of HF or VA (both p ns), nor was mean global FD. There were no significant differences in the survival curves of both endpoints between the two groups: HR were 2.34 (95% CI 0.74–7.4, p 0.13) and 1.15 (95% CI 0.45–2.41, p 0.71) respectively for HF and VA (Image 1). LVEF and LGE remained consistent predictors of events. Conclusions In a large multicenter retrospective LVNC study, the degree of hypertrabeculation measured by fractal analysis was not associated with functional LV parameters and, most importantly, with the incidence of cardiovascular events. Therefore, our results suggest that diagnostic LVNC criteria should be refined to include parameters with actual prognostic implications. Funding Acknowledgement Type of funding sources: None.

Invasive validation of pressure-volume loops derived from cardiovascular magnetic resonance imaging and brachial blood pressure in heart failure patients

Abstract Introduction Left ventricular (LV) pressure-volume (PV) loops provide gold-standard physiological information but require invasive measurements of ventricular intracavity pressure, limiting clinical and research applications. Recent development has seen the introduction of non-invasively computed PV loops from cardiovascular magnetic resonance (CMR) volumetry and a brachial blood pressure measurement. The approach combines LV volumes with a time-varying elastance function to compute time-resolved LV pressures and was validated on invasive pressure data from a porcine model. The method is readily implemented using standard CMR sequences and provides measures of hemodynamic parameters including stroke work, myocardial efficiency, and contractile state. However, the method remains to be validated in patients using invasive left ventricular pressure recordings. Purpose To validate for the first time in human patients the performance of non-invasively computed PV loops against invasive measures. Methods Four heart failure patients underwent two subsequent sessions of CMR cine imaging and simultaneous brachial blood pressure measurement, with intravenous administration of two different vasoactive drugs, resulting in two different haemodynamic states for each patient. LV catheterization was then conducted with repeat administration of the same infusions. Pressure-volume loops were computed from CMR volumes combined with 1) a time-varying elastance function scaled to brachial blood pressure and temporally stretched to match volume data, and 2) invasive pressures averaged from multiple sampled beats. Method comparison was conducted using linear regression and Bland-Altman analysis. Results Figure 1 shows non-invasively derived PV loop parameters compared to invasive data. The non-invasive method demonstrated strong correlations and low bias for stroke work (R2=0.97, bias 4.6%, p&amp;lt;0.0001), potential energy (R2=0.83, bias 1.5%, p=0.001), end-systolic pressure-volume relationship (R2=0.90, bias 5.4%, p=0.0003), energy per ejected volume (R2=0.93, bias 3.5%, p=0.0001), ventricular efficiency (R2=0.99, bias 1.1%, p&amp;lt;0.0001), arterial elastance (R2=0.87, bias −7.8%, p=0.0006), and mean external power (R2=0.89, bias 4.6%, p=0.0005). Conclusions Pressure-volume loops can be precisely and accurately computed from cardiovascular magnetic resonance imaging and brachial cuff blood pressure in humans, and is ready for use in research applications. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Swedish Heart Lung Foundation