LGE CMR Research Articles

Adaptive dynamic inference for few-shot left atrium segmentation

Accurate segmentation of the left atrium (LA) from late gadolinium-enhanced cardiac magnetic resonance (LGE CMR) images is crucial for aiding the treatment of patients with atrial fibrillation. Few-shot learning holds significant potential for achieving accurate LA segmentation with low demand on high-cost labeled LGE CMR data and fast generalization across different centers. However, accurate LA segmentation with few-shot learning is a challenging task due to the low-intensity contrast between the LA and other neighboring organs in LGE CMR images. To address this issue, we propose an Adaptive Dynamic Inference Network (ADINet) that explicitly models the differences between the foreground and background. Specifically, ADINet leverages dynamic collaborative inference (DCI) and dynamic reverse inference (DRI) to adaptively allocate semantic-aware and spatial-specific convolution weights and indication information. These allocations are conditioned on the support foreground and background knowledge, utilizing pixel-wise correlations, for different spatial positions of query images. The convolution weights adapt to different visual patterns based on spatial positions, enabling effective encoding of differences between foreground and background regions. Meanwhile, the indication information adapts to the background visual pattern to reversely decode foreground LA regions, leveraging their spatial complementarity. To promote the learning of ADINet, we propose hierarchical supervision, which enforces spatial consistency and differences between the background and foreground regions through pixel-wise semantic supervision and pixel-pixel correlation supervision. We demonstrated the performance of ADINet on three LGE CMR datasets from different centers. Compared to state-of-the-art methods with ten available samples, ADINet yielded better segmentation performance in terms of four metrics.

Abstract 13253: Remotely-Controlled Cantilevered Cardiac Shim Coil (CSS) Corrects Cardiac MRI Magnetic-Field Inhomogeneities Due to Implanted Cardioverter Defibrillators (ICDs): Preclinical Validation

Introduction: 1.4M people (US) have implanted ICDs, which reduce risk of sudden death due to ventricular arrhythmias. Cardiac MRI (cMR) is used in patients with ICDs to diagnose conditions that predispose to sudden death and to plan and guide ablation therapy. However, all ICDs contain a ferromagnetic transformer which imposes a large inhomogeneous (>100 parts-per-million, ppm) magnetic field in sections of the heart, creating large image voids that can mask pathology, such as myocardial scar. Wide-band Late Gad. Enhancement (LGE) imaging has improved evaluation of ICD patients, handling < 25ppm artifacts, leaving unreadable voids in ~30% of patients. Hypothesis: ICD artifacts can be reduced with a remotely-displaced cardiac shim system (CSS), allowing clinical CMR imaging. Methods: The CSS system (Fig. 1A- C). A shim coil, placed in the bore, was designed to correct 75ppm fields at 15cm distances, using currents supplied from the MRI operator room (OpRm). The coil is immune to magnetic forces. A cantilevered beam holds the shim coil over the patient’s chest above the cardiac imaging coil allowing unrestricted imaging. MR-conditional motors, remotely-controlled from the OpRm, allow 2mm-resolution 3D shim-coil positioning. Experiments : swine (N=3) with chest-overlaid ICDs, emulating patients, were imaged. Magnetic-field maps were used to estimate shim-coil positioning, and current magnitude & polarity. Fine-tuning of location and current was performed during continuous 2D ECG-gated breath-held GRE/SSFP imaging. 2D/3D LGE cMR was subsequently acquired and evaluated. Results: CSS reduced field inhomogeneities due to implanted ICDs by 30ppm in 2D and 3D cMR sequences, correcting ICD-related image distortions in several heart regions (Fig. 1D, E). Conclusion: An externally-controlled shim-coil localization and drive system reduced artifacts without requiring entry into the scanner room, supporting efficient, higher quality cMR imaging of ICD patients.

Diagnostic quality and clinical utility of cardiovascular magnetic resonance in patients with subcutaneous ICDs

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiovascular magnetic resonance (CMR) is increasingly requested in patients with cardiac implantable electronic devices (CIEDs) – particularly for scar identification in patients with ventricular arrhythmias and implantable cardiac defibrillators (ICDs). Image artefact can be challenging in patients with larger devices, and patients with subcutaneous ICDs (S-ICDs) may not be referred due to concerns about non-diagnostic imaging. Modified sequences including wide band MOCO with PSIR (WB-MOCO) have been used to reduce image artefact in patients with CIEDs. We evaluated the image quality and clinical impact of gradient echo cine imaging and LGE CMR imaging in patients with S-ICDs. Methods Twenty CMR scans were performed adhering to manufacturer conditions in 19 patients (mean age 42± 13 years, 68% male) with MR conditional S-ICDs over four years.All patients were scanned at 1.5T at a single UK tertiary centre, with sequence modification using a pre-defined sequence protocol including gradient echo cine imaging, and WB-MOCO where conventional LGE showed artefact. LGE images were reviewed and graded for artefact by two independent observers, both by AHA segment and for overall quality on a scale of 0–4 (Grade 0 = no artefact, Grade 2 = 2–3 segments obscured by artefact, Grade 4 = entire myocardium obscured). Segments were viewed in both long and short axis orientations and deemed diagnostic if visible in at least one orientation. Clinical utility was assessed using pre-defined criteria, based on review of electronic medical records. Ethical approval was obtained from the Health Research Authority(REC21/EE/0037). Results CMR scans were performed in all patients without complication, excepting loss of ICD beeper function in 3 (16%) of patients (manufacturer recognised complication). S-ICDs were implanted for secondary prevention in 50% of cases with 63% patients having non-ischaemic cardiomyopathies. Scan indications included assessment of aetiology of heart failure (25%), ischaemic heart disease (20%), suspected left ventricular thrombus (20%), myocarditis (20%), scar assessment for viability (5%) miscellaneous (10%). Volumetric analysis from cine imaging was possible in 80%. LGE was present in 19 (95%) scans. Conventional LGE was only successful in 10% (2; 1 grade 0, 1 grade 1). Where WB-MOCO was used (n=18) this improved to 83% (grade 0 in 72%, grade 1 in 11%) with 95%being diagnostic (just 5% grade 3, 0% grade 4). Artefact was most commonly seen in the mid inferolateral segment (33% scans). Where follow-up data was available (19/20 scans), CMR led to a new diagnosis in 2 (10%) of scans and changes in management in 10 (53%) of scans. Conclusion Scar imaging using CMR can be safely performed in patients with S-ICDs, with diagnostic LGE imaging feasible in the majority (95% scans grades 0–2) and diagnostic cine imaging (in 80%) with the results providing high clinical yield.

Impact of the individual relationship between focal or rotational regions of interest and atrial cardiomyopathy in patients with chronic forms of atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background The mechanisms for the initiation and perpetuation of atrial fibrillation (AF) are still not completely understood. The CARTOFINDER module represents a novel approach for the visualisation of repetitive focal and rotational activations in patients with AF. Purpose The aim of this prospective observational study was to evaluate the potential relationship between findings from CARTOFINDER mapping and individual atrial arrhythmia substrates. Beyond that, the impact of atrial fibrosis on patients’ outcome was analysed. Methods A total of 20 consecutive patients (69 ± 9 years, 55 % male) underwent ablation for persistent AF (PERS) applying a 3D-mapping system with the integrated CARTOFINDER module. Regions of interest (ROIs) were identified before ablation. The individual amount and distribution of atrial fibrosis in the left atrium (LA) based on anatomical segments was determined by LGE CMR prior to the ablation procedure. 3, 6 and 12 month-follow-up data were assessed. Results In all patients, ablation procedures were performed successfully (n=20, 100%). LA mapping time was 09.30 ± 03.53 min, mean ablation duration was 26.40 ± 07.51 mi, mean fluoroscopy time amounted to 6.66 ± 1.85 min. Consistent with Utah classes II-III, LGE-CMR revealed an intermediate degree of 21.41 ± 6.16% LA fibrosis. Focal and rotational ROIs were identified in all patients (mean no ROIs per Patient n = 416.45 ± 204.57). Univariate logistic regression calculation documented no consistent correlation between the percentage of LA fibrosis and the probability for the occurrence of ROIs (posterior: regression coefficient (b) =0.36, p-value (p) =0.24; anterior: b=-0.08, p=0.54; lateral: b=0.31, p=0,39; septal:b=-0.12; p=0.66; right PVs: b=0.34, p=0.27; left PVs: b=0.07, p=0.79; LAA: -0.91, p=0.11). Between the degree of atrial cardiomyopathy and the number of ROIs no association was observed (b=10.86, p=0.15). 12 months AF-free survival amounted to 70% (n=14). The degree of LA fibrosis showed no significant correlation with AF-free survival (logistic regression: posterior: b=0.33, p=0.12; anterior: b=-0.03, p=0.83; lateral: b=0.31, p=0,35; septal:b=-0.07; p=0.79; right PVs: b=0.81, p=0.15; left PVs: b=0.37, p=0.25; LAA: -0.16, p=0.54). Conclusions This study reports on initial observations concerning the relationship between focal and rotational activations and atrial fibrosis in PERS AF. No evidence for a consistent correlation between the occurrence or number of ROIs and the degree of atrial arrhythmia substrates was revealed. Beyond that, the amount of LA fibrosis did not correlate with the 12 months AF-free survival rate. Larger studies are warranted to verify our first results.

Abstract 12050: Ketone Ester Supplementation Reduces Cardiac Inflammation and Enhances Cardiac Energetics in Acute Myocardial Infarction

Introduction: Myocardial infarction (MI) is a major risk factor for the development of heart failure with reduce ejection fraction (HFrEF). While previous studies have focused on HFrEF, the role of ketone bodies in MI is unclear. Hypothesis: K etone may exert some cardioprotective effects following MI. Methods: Male Yorkshire pigs underwent percutaneous balloon occlusion of the LAD for 80 minutes followed by 72 hours reperfusion period. Oral ketone ester (BHB-butanediol monoester, KE, 550 mg/kg) or vehicle was administered during reperfusion and continued during the follow-up period. Simultaneous blood sampling from coronary sinus and artery was obtained to quantify the extraction fraction of major cardiac substrates. Scar size was measured by LGE CMR and molecular markers were assessed in the LV. The study was approved by the IACUC at the Massachusetts General Hospital. Results: KE induced ketosis within 30 min after ingestion. KE increased β-hydroxybutyrate (βOHB) extraction in healthy swine without affecting glucose and fatty acid (FA) consumption. Despite similar infarct size in both MI and MI-KE groups, cardiac expression of proinflammatory cytokines TNF-⍺, IL-1, IL-6, and cardiac injury TTNI3 alongside with plasma hs-cTnI were reduced by KE. The untreated MI hearts consumed less FA with no changes in glucose uptake, whereas hearts from KE-treated animals consumed more βOHB and FA. KE increased cardiac expression of genes involved in ketone utilization MCT1 and SCOT after MI (p<0.05 for all), indicating that cardiac uptake and utilization of βOHB as fuel were augmented. Together these metabolic changes were associated with an increase in cardiac ATP production. RNA-seq analysis identified differentially expressed genes related to mitochondrial energy metabolism. Conclusions: Oral KE induced ketosis and enhanced cardiac βOHB extraction in both healthy and infarcted hearts. Although infarct size was unchanged 72h after MI, acute oral supplementation with KE supressed cardiac inflammation and injury, altered cardiac substrate uptake and enhanced cardiac energetics following acute MI. Evaluating the potential chronic benefits of these changes on long-term remodeling after MI will be an exciting direction for future studies.

JAS-GAN: Generative Adversarial Network Based Joint Atrium and Scar Segmentations on Unbalanced Atrial Targets.

Automated and accurate segmentations of left atrium (LA) and atrial scars from late gadolinium-enhanced cardiac magnetic resonance (LGE CMR) images are in high demand for quantifying atrial scars. The previous quantification of atrial scars relies on a two-phase segmentation for LA and atrial scars due to their large volume difference (unbalanced atrial targets). In this paper, we propose an inter-cascade generative adversarial network, namely JAS-GAN, to segment the unbalanced atrial targets from LGE CMR images automatically and accurately in an end-to-end way. Firstly, JAS-GAN investigates an adaptive attention cascade to automatically correlate the segmentation tasks of the unbalanced atrial targets. The adaptive attention cascade mainly models the inclusion relationship of the two unbalanced atrial targets, where the estimated LA acts as the attention map to adaptively focus on the small atrial scars roughly. Then, an adversarial regularization is applied to the segmentation tasks of the unbalanced atrial targets for making a consistent optimization. It mainly forces the estimated joint distribution of LA and atrial scars to match the real ones. We evaluated the performance of our JAS-GAN on a 3D LGE CMR dataset with 192 scans. Compared with the state-of-the-art methods, our proposed approach yielded better segmentation performance (Average Dice Similarity Coefficient (DSC) values of 0.946 and 0.821 for LA and atrial scars, respectively), which indicated the effectiveness of our proposed approach for segmenting unbalanced atrial targets.

Dark-blood late gadolinium enhancement CMR improves detection of papillary muscle fibrosis in patients with mitral valve prolapse

PurposePapillary muscle fibrosis may act as an arrhythmogenic substrate in patients with mitral valve prolapse (MVP). Previous studies used conventional bright-blood late gadolinium enhancement cardiovascular magnetic resonance (LGE CMR) imaging to assess papillary muscle fibrosis, although this technique suffers from poor scar-to-blood contrast which may limit its sensitivity, in contrast to dark-blood LGE. This study sought to compare bright-blood and dark-blood LGE for the detection of papillary muscle fibrosis in patients with MVP. Method60 patients with known isolated MVP referred for CMR were prospectively recruited. A routine CMR protocol was used to obtain cine imaging, dark-blood LGE and bright-blood LGE in three long-axis views and a stack of short-axis views. Flow mapping of the proximal aorta was performed to calculate mitral regurgitant volume. Images were analysed for cardiac volumes, ejection fraction, mitral regurgitation severity, MVP characteristics (mitral annular disjunction, prolapse volume) and presence of LGE at the papillary muscles and myocardium. ResultsDark-blood LGE detected significantly more subjects with LGE at the papillary muscles than bright-blood LGE (35% vs 15%, p = 0.002). There was no difference between LGE techniques regarding myocardial (non-papillary muscle) fibrosis (present in 25% each). No statistical differences were observed between patients with or without LGE at the papillary muscles regarding demographics, clinical data (including ventricular arrhythmia) and MVP characteristics. Furthermore, no association was found between LGE at the papillary muscles and at the myocardium. ConclusionsCompared to bright-blood LGE, dark-blood LGE CMR improves the detection of LGE at the papillary muscles in patients with MVP.

Magnitude of ST-segment Elevation Is Associated with Increased Acute Inflammatory Response and Myocardial Scar in Patients with Acute Myocardial Infarction Undergoing pPCI

ABSTRACT Background: The integrated ST segment elevation score (ISSTE) score objectively quantifies the ECG changes before and after primary percutaneous coronary intervention (pPCI) for ST segment elevation myocardial infarction (STEMI). The inflammatory response is a major component in scar formation and remodeling process of the myocardial tissue following myocardial infarction (MI). Cardiac magnetic resonance imaging (CMR) precisely quantifies the cardiac function and assesses the pattern of the myocardial scar tissue. The aim of the study was to evaluate the relations between the ISSTE score and: (1) acute inflammatory biomarkers and (2) extent of the myocardial scar determined by CMR in STEMI treated with pPCI. Material and methods: One hundred thirty STEMI patients were included in the study, who underwent pPCI in the first 12 hours from symptom debut. ISSTE-1 was calculated at presentation and 2 hours following pPCI (ISSTE-2). Inflammatory biomarkers were determined at admission and day 5, followed by LGE-CMR at 4 weeks, with quantification of cardiac function and extent of infarct size (IS) and transmurality. Patients were divided in low and high ISSTE groups based on the median values. Results: No significant differences were noted in terms of CMR parameters or inflammatory biomarkers and between the groups with low or high ISSTE-1. Significantly higher levels of day-5 hs-CRP (p = 0.03) and day-1 IL-6 (p = 0.02), MMP-9 (p = 0.05) were recorded in high ISSTE-2 groups. LV IS mass (23.11 ± 5.31 vs. 57.94 ± 8.33, p = 0.001), percentage (13.55 ± 6.22 vs. 27.15 ± 7.12, p = 0.001) and transmurality (p = 0.001) was significantly higher in ISSTE-2 group. ISSTE-2 significantly correlated with LV IS mass (r = 0.391, p <0.0001), percentage (r = 0.541, p <0.0001) high transmurality (r = 0.449, p <0.0001) and LV EF (r = -0.397, p <0.0001). Conclusions: A high ISSTE-2 score is associated with increased inflammatory response exhibited by elevated serum IL-6 and MMP-9 levels determined on the day of admission, and with persistently increased serum hs-CRP levels on day 5 of the acute event. A higher ISSTE-2 score is associated with larger myocardial scar extent expressed by IS, higher transmurality and reduced LV EF at 1-month LGE CMR follow-up.

Myocardial Work, an Echocardiographic Measure of Post Myocardial Infarct Scar on Contrast-Enhanced Cardiac Magnetic Resonance

This study investigates the relation of non-invasive myocardial work and myocardial viability following ST-segment elevation myocardial infarction (STEMI) assessed on late gadolinium contrast enhanced cardiac magnetic resonance (LGE CMR) and characterizes the remote zone using non-invasive myocardial work parameters. STEMI patients who underwent primary percutaneous coronary intervention (PCI) were included. Several non-invasive myocardial work parameters were derived from speckle tracking strain echocardiography and sphygmomanometric blood pressure, e.g.: myocardial work index (MWI), constructive work (CW), wasted work (WW) and myocardial work efficiency (MWE). LGE was quantified to determine infarct transmurality and scar burden. The core zone was defined as the segment with the largest extent of transmural LGE and the remote zone as the diametrically opposed segment without LGE. A total of 53 patients (89% male, mean age 58 ± 9 years) and 689 segments were analyzed. The mean scar burden was 14 ± 7% of the total LV mass, and 76 segments (11%) demonstrated transmural hyperenhancement, 280 (41%) non-transmural hyperenhancement and 333 (48%) no LGE. An inverse relation was observed between segmental MWI, CW and MWE and infarct transmurality (p < 0.05). MWI, CW and MWE were significantly lower in the core zone compared to the remote zone (p<0.05). In conclusion, non-invasive myocardial work parameters may serve as potential markers of segmental myocardial viability in post-STEMI patients who underwent primary PCI. Non-invasive myocardial work can also be utilized to characterize the remote zone, which is an emerging prognostic marker as well as a therapeutic target.

Changes on myocardial perfusion scintigraphy and contrast-enhanced cardiac magnetic resonance imaging after definitive radiotherapy in patients with lung cancer

AbstractAim:To determine whether myocardial perfusion scintigraphy (MPS) changes in lung cancer patients treated with radiotherapy (RT) were detectable with late gadolinium enhancement cardiac magnetic resonance imaging (LGE CMR).Materials and methods:Twenty-one patients with lung cancer were evaluated pre-RT and at 2 and 6 months post-RT follow-up (FU) with MPS and LGE CMR. MPS changes in the left ventricle (LV) were analysed using the semi-quantitative summed rest score method (20 segments) and the Bull’s-eye-view technique. The LGE CMR studies were analysed for visual signs of myocardial damage (fibrosis), that is, focal LGE in the LV and cardiac function parameters.Results:MPS changes were detected in 7/20 patients at 2 months FU and in 8/13 patients at 6 months FU. Only one patient had a new irreversible defect judged to be caused by direct irradiation. MPS changes in two cases were deemed to be caused by attenuation. All new MPS defects were minor and no corresponding myocardial damage, or any functional changes, were evident on LGE CMR.Findings:The extent of MPS changes at 6 months FU appeared less prominent than in previous reports. No visual signs or functional changes corresponding to myocardial damage were detected on LGE CMR. A risk for false-positive MPS changes caused by attenuation is evident.

Non-invasive myocardial work: an echocardiographic measure of post-infarct scar on contrast-enhanced cardiac magnetic resonance imaging

Abstract Background Late gadolinium contrast enhanced cardiac magnetic resonance (LGE CMR) imaging accurately quantifies the extent of fibrosis and transmurality in chronically infarcted left ventricular (LV) segments, and identifies viability. Moreover, CMR characterizes the remote, non-infarcted zone, which is an emerging region of interest following ST-segment elevation myocardial infarction (STEMI). Non-invasive myocardial work is a novel LV function parameter - calculated from speckle-tracking strain echocardiography and sphygmomanometrically-determined blood pressure, which has shown excellent correlation with invasively measured myocardial work. Purpose To explore the relation of non-invasively estimated parameters of LV myocardial work to post-infarct scar on LGE CMR, and to compare myocardial work indices between the infarct core and remote zone in STEMI patients who were treated with primary percutaneous coronary intervention (PCI). Methods Patients with a STEMI who underwent primary PCI and LGE CMR, in addition to echocardiographic studies where non-invasive myocardial work analysis was feasible, were included. The LV was subdivided into non-infarcted, non-transmural and transmurally infarcted segments. The remote zone was defined as the non-infarcted myocardial segment diametrically opposed to the infarct core, without any evidence of LGE. Myocardial work indices were compared with linear mixed models, ANOVA and Wilcoxon signed rank tests. Results 53 patients (89% male, age 58±9 years) and 689 segments were analysed. The mean scar burden comprised 14±7% of the total LV mass and 76 (11%) segments showed transmural LGE. The following non-invasive myocardial work indices: myocardial work index (MWI), constructive work (CW) and myocardial work efficiency (MWE) showed a significant inverse relationship with infarct transmurality (p&amp;lt;0.05 for all comparisons) while a positive trend was observed for wasted work (WW) (p=0.086) (Figure 1). The core zone demonstrated lesser MWI (1237±568 vs. 1514±518 mmHg%; p=0.010), CW (1331±627 vs. 1827±537 mmHg%; p&amp;lt;0.001) and MWE (92 (84–98) vs. 98 (95–99) %; p&amp;lt;0.001) as well as greater WW when compared to the remote zone (107 (26–196) vs. 26 (10–90) mmHg%; p=0.001). Conclusions In STEMI patients who underwent primary PCI, MWI, CW and MWE were significantly related to the extent of transmural infarction, while WW demonstrated a trend. MWI, CW and MWE were significantly lower, and WW higher, in the core zone compared to the remote zone. Non-invasive myocardial work indices may provide an echocardiographic method for determining post-infarct viability, as well as characterization of the remote zone. MW and scar transmurality on LGE CMR Funding Acknowledgement Type of funding source: None

Left ventricular thrombus on cardiovascular magnetic resonance imaging in non-ischaemic cardiomyopathy.

Case reports have described left ventricular (LV) thrombus in patients with non-ischaemic cardiomyopathy (NICM). We aimed to systematically study the characteristics, predictors, and outcomes of LV thrombus in NICM. Forty-eight patients with LV thrombus detected on late gadolinium enhancement cardiovascular magnetic resonance imaging (LGE CMR) in NICM were compared with 124 patients with LV thrombus in ischaemic cardiomyopathy (ICM), and 144 matched patients with no LV thrombus in NICM. The performance of echocardiography for the detection of LV thrombus was compared between NICM and ICM. The 12-month incidence of embolism was compared between the three study groups. Independent predictors of LV thrombus in NICM were LV ejection fraction (LVEF) [hazard ratio (HR) 1.36 per 5% decrease; P = 0.002], LGE presence (HR 6.30; P < 0.001), and LGE extent (HR 1.33 per 5% increase; P = 0.001). Compared with patients with LV thrombus in ICM, those with LV thrombus in NICM had a 10-fold higher prevalence of thrombi in other cardiac chambers. The performance of echocardiography for the detection of LV thrombus was not different between NICM and ICM. The 12-month incidence of embolism associated with LV thrombus was not different between NICM and ICM (8.7% vs. 6.8%; P = 0.69) but both were higher compared with no LV thrombus in NICM (1.5%). Independent predictors of LV thrombus in NICM were lower LVEF, LGE presence, and greater LGE extent. The 12-month incidence of embolism associated with LV thrombus in NICM was not different compared with LV thrombus in ICM.

P1338 Anomalous left coronary artery from pulmonary artery syndrome diagnosed in adulthood: case of a mother of five

Abstract Funding Acknowledgements Project no. NVKP_16-1-2016-0017 has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary Introduction Bland-White-Garland syndrome or ALCAPA (anomalous left coronary artery from pulmonary artery) syndrome is a rare congenital disorder with a prevalence of 1: 300,000. This condition is one the most common causes of infant myocardial infarction. It can ultimately lead to heart failure before the age of one, however when pronounced left and right coronary artery collateralization is present, patients may remain asymptomatic until older age. Due to the development and availability of non-invasive imaging techniques, these patients diagnosed more frequently in recent years. Case description: We present a 53-year-old patient with treated hypertension and five uncomplicated pregnancies. At the age of 40, the patient was referred to coronary angiography due to her dyspnea on exertion. The examination showed that the left main coronary artery (LMCA) originates from the pulmonary artery 7 mm above the pulmonary valve and the right coronary artery is significantly dilated. Based on the mild complaints and good left ventricle systolic function, conservative therapy was recommended by the cardiac surgery team. Since 2018 the patient has had gradually worsening complaints despite of the therapy adjusted for chronic heart failure. Q-waves were depicted on the 12-lead ECG in aVL and V1-V6 leads. Echocardiography showed dilated left ventricle (LV), LV hypertrophy, diffuse hypokinesia, decreased LV systolic function and diastolic dysfunction. At our clinic, we performed cardiac magnetic resonance imaging (CMR) which showed moderately reduced LV ejection fraction, diffuse LV hypokinesia, increased LV volume, septal LV hypertrophy. We visualized the retrograde flow on the LMCA, the shunt volume at the anomalous artery was 1,27 L/min. The CMR also showed irreversible damage of the subendocardial region of the myocardium via late gadolinium enhancement in the area supplied by the LMCA. Since we planned to reevaluate the surgical possibilities, the collateral network with tortuous and dilated left and right coronary arteries were visualized by coronary CT angiography. The surgical team at our institute decided to perform myocardial revascularization and restoration of dual coronary artery supply. Discussion ALCAPA is usually diagnosed in infancy however, in about 10-15% of cases the disease is only recognized in adulthood. The long-term morphological and functional characteristics of the syndrome may include reversible/irreversible ischemic damage, systolic and diastolic dysfunction, mitral regurgitation, significant collateral circulation, left-to-right shunt, dilated coronary arteries. Surgical myocardial revascularization and restoration of dual coronary artery supply is recommended even in adult patients. Abstract P1338 Figure. CTA reconstruction and LGE CMR

P1393 Intervendor difference in global and regional 2D speckle tracking strain. comparison against cMR tagging

Abstract Funding Acknowledgements Fondation de Recherche Scientifique Belge FRSM PDR 19488731 BACKGROUND 2D-speckle-tracking (ST) echocardiography is currently widely used for estimation of global (G) and regional myocardial deformation. In previous works, we showed good correlation between global longitudinal (LS) and circumferential strain (CS) from one 2DST vendor with cMR-Tagging, however with significant bias between both methods. Also, we found poorer agreement between 2DST and cMR-Tagging on regional basis. However it is unknown how 2DST from other vendors would comparte to cMR tagging. PURPOSE To asssess vendor differences in global and regional strain assessment and compare 1) the agreement of 2 different 2DST softwares for global and regional LS and CS among each other and against cMR-Tagging as reference; and 2) the accuracy of both softwares to detect infarcted segments. METHODS 100 subjects with different cardiac disease (among which 31 with chronic infarct) underwent 2DST and tagging and LGE cMR on the same day. Global and regional CS (16 AHA segments) and LS (18 AHA segments) was computed using 2 different ST vendor softwares and compared to cMR-Tagging with HARP. Accuracy of regional 2D-ST by both vendors to detect infarcted segments (ie &amp;gt;75% transmurality of late gadolinium) was compared using ROC analysis. RESULTS Global LS (ICC = 0.87) and CS 2DST (ICC = 0.83, p &amp;lt; 0.001) agreed well between both vendors, but GCS values of vendor2 were significantly greater than that of vendor 1. Also we fond good correlation between ST of both vendors and cMR-Tagging for GLS (ICC = 0.80 and ICC = 0.69 for vendor 1 and 2 respectively) and GCS (ICC = 0.64 and ICC = 0.50 for vendor 1 and 2 respectively). Bias for GLS (-4.6 ± 2.9% and -6.1 ± 3.8% for vendor 1 and 2 respectively) vs cMR-Tagging was similar, however GCS of vendor 2 had higher bias vs cMR-Tagging (-16.0 ± 8.5%) than vendor 1 (-5.1 ± 5.8%). Agreement for regional strains is shown in the figure below. Overall, regional LS and CS agreed adequately among both vendors. Agreement of regional LS and CS vs cMR-tagging was slightly better for vendor 1, with less bias than for vendor 2, and disagreement was similarly located (ie agreement with cMR-Tagging for LS in inferolateral inferior and inferoseptal basal segments). The predictive accuracy of regional CS and LS for detecting segments with infarct was higher for vendor 2 (AUC 0.76 and 0.68) than for vendor 1 (AUC 0.70 and 0.63) . CONCLUSION GLS agreed well among both vendors and with cMR-Tagging, confirming the universal validity of this measurement. However vendor 2 provided significantly greater GCS values and had higher bias against cMR-Tagging than vendor 1. On regional basis CS and LS agreed moderately well among both vendors, however vendor 2 agreed less with cMR-Tagging than vendor 1, but astoundingly had higher diagnostic accuracy for detecting infarct. Overall this findings call for further efforts in standardization of 2DST CS and regional strain. Abstract P1393 Figure.

Clinical impact of cardiovascular magnetic resonance with optimized myocardial scar detection in patients with cardiac implantable devices

BackgroundMyocardial scar assessment using late gadolinium enhancement Cardiovascular Magnetic Resonance (LGE CMR) is commonly indicated for patients with cardiac implantable electronic devices (CIEDs), however metal artifact can degrade images.We evaluated the clinical impact of LGE CMR incorporating a device-dependent metal artifact reduction strategy in patients with CIEDs. Methods136 CMR studies were performed in 133 consecutive patients (age 56 ± 19 years, 69% male) with CIEDs (22% implantable loop recorders [ILRs], 40% permanent pacemakers [PPMs], 38% implantable cardioverter defibrillators [ICDs]; 42% non-MRI conditional) over 2 years, without complication. LGE imaging was tailored to the CIED, using a wideband sequence for left-sided PPMs and ICDs and conventional sequences for ILRs and right-sided PPMs, scoring segmental artifact. Diagnostic utility and impact on clinical management were scored by consensus of experts. ResultsCMR provided unexpected diagnoses in 22 (16%) and changed management in 113 (83%) patients. Myocardial scar was present in 92 (68%), with other abnormalities detected in another 13%. Using conventional LGE, 43 (32%) studies were non-diagnostic (79% of defibrillators) compared to 0% using wideband LGE imaging. Wideband LGE results changed clinical management in an additional 39 (75%) defibrillator patients and 10 (19%) pacemaker patients when compared to imaging with conventional LGE sequences. ConclusionThe clinical yield from CMR using optimized LGE sequences in patients with CIEDs is high with no demonstrated clinical risk. A device-dependent LGE imaging strategy using wideband LGE is needed to achieve clinical utility especially in ICD recipients.

High spatial resolution free-breathing 3D late gadolinium enhancement cardiac magnetic resonance imaging in ischaemic and non-ischaemic cardiomyopathy: quantitative assessment of scar mass and image quality

PurposeTo compare breath-hold (BH) with navigated free-breathing (FB) 3D late gadolinium enhancement cardiac MRI (LGE-CMR)Materials and methodsFifty-one patients were retrospectively included (34 ischaemic cardiomyopathy, 14 non-ischaemic cardiomyopathy, three discarded). BH and FB 3D phase sensitive inversion recovery sequences were performed at 3T. FB datasets were reformatted into normal resolution (FB-NR, 1.46x1.46x10mm) and high resolution (FB-HR, isotropic 0.91-mm voxels). Scar mass, scar edge sharpness (SES), SNR and CNR were compared using paired-samples t-test, Pearson correlation and Bland-Altman analysis.ResultsScar mass was similar in BH and FB-NR (mean ± SD: 15.5±18.0 g vs. 15.5±16.9 g, p=0.997), with good correlation (r=0.953), and no bias (mean difference ± SD: 0.00±5.47 g). FB-NR significantly overestimated scar mass compared with FB-HR (15.5±16.9 g vs 14.4±15.6 g; p=0.007). FB-NR and FB-HR correlated well (r=0.988), but Bland-Altman demonstrated systematic bias (1.15±2.84 g). SES was similar in BH and FB-NR (p=0.947), but significantly higher in FB-HR than FB-NR (p<0.01). SNR and CNR were lower in BH than FB-NR (p<0.01), and lower in FB-HR than FB-NR (p<0.01).ConclusionNavigated free-breathing 3D LGE-CMR allows reliable scar mass quantification comparable to breath-hold. During free-breathing, spatial resolution can be increased resulting in improved sharpness and reduced scar mass.Key Points• Navigated free-breathing 3D late gadolinium enhancement is reliable for myocardial scar quantification.• High-resolution 3D late gadolinium enhancement increases scar sharpness• Ischaemic and non-ischaemic cardiomyopathy patients can be imaged using free-breathing LGE CMR.

Optimization of late gadolinium enhancement cardiovascular magnetic resonance imaging of post-ablation atrial scar: a cross-over study

BackgroundCardiovascular magnetic resonance (CMR) imaging may be used to visualize post-ablation atrial scar (PAAS), and three-dimensional late gadolinium enhancement (3D LGE) is the most widely employed technique for imaging of chronic scar. Detection of PAAS provides a unique non-invasive insight into the effects of the ablation and may help guide further ablation procedures. However, there is evidence that PAAS is often not detected by CMR, implying a significant sensitivity problem, and imaging parameters vary between leading centres. Therefore, there is a need to establish the optimal imaging parameters to detect PAAS.MethodsForty subjects undergoing their first pulmonary vein isolation procedure for AF had detailed CMR assessment of atrial scar: one scan pre-ablation, and two scans post-ablation at 3 months (separated by 48 h). Each scan session included ECG- and respiratory-navigated 3D LGE acquisition at 10, 20 and 30 min post injection of a gadolinium-based contrast agent (GBCA). The first post-procedural scan was performed on a 1.5 T scanner with standard acquisition parameters, including double dose (0.2 mmol/kg) Gadovist and 4 mm slice thickness. Ten patients subsequently underwent identical scan as controls, and the other 30 underwent imaging with a reduced, single, dose GBCA (n = 10), half slice thickness (n = 10) or on a 3 T scanner (n = 10). Apparent signal-to-noise (aSNR), contrast-to-noise (aCNR) and imaging quality (Likert Scale, 3 independent observers) were assessed. PAAS location and area (%PAAS scar) were assessed following manual segmentation. Atrial shells with standardised %PAAS at each timepoint were then compared to ablation lesion locations to assess quality of scar delineation.ResultsA total of 271 3D acquisitions (out of maximum 280, 96.7%) were acquired. Likert scale of imaging quality had high interobserver and intraobserver intraclass correlation coefficients (0.89 and 0.96 respectively), and showed lower overall imaging quality on 3 T and at half-slice thickness. aCNR, and quality of scar delineation increased significantly with time. aCNR was higher with reduced, single, dose of GBCA (p = 0.005).Conclusion3D LGE CMR atrial scar imaging, as assessed qualitatively and quantitatively, improves with time from GBCA administration, with some indices continuing to improve from 20 to 30 min. Imaging should be performed at least 20 min post-GBCA injection, and a single dose of contrast should be considered.Trial registrationTrial registry- United Kingdom National Research Ethics Service 08/H0802/68 – 30th September 2008.

Role of cardiac MRI in assessment of patients with dilated cardiomyopathy

PurposeTo study additive role of CMR to echocardiography in assessment of dilated cardiomyopathy and if LGE-CMR myocardial enhancement pattern can differentiate between ischemic and non-ischemic dilated cardiomyopathy compared to coronary catheterization as a reference standard. Methods and materialsEligible 35 patients with dilated cardiomyopathy were involved in our study and included on basis of echocardiographic findings. All patients were subjected to history taking, trans-thoracic echocardiography, diagnostic coronary angiography, and late gadolinium enhanced CMR (LGE CMR). CMR used for assessment of cardiac morphology, function, segmental wall motion abnormalities (SWMA), presence, pattern, and transmularity index of myocardial scars. ResultsIt was found that CMR capable of detecting myocardial scars and differentiating between ischemic and non-ischemic ones as compared to coronary catheterization data with a highly statistically significant difference (p < 0.001). Good negative correlation (p = 0.002) between grade of transmularity index of detected myocardial scar and LVEF. Strong positive correlation between grade of transmularity index of detected myocardial scar and number of affected myocardial segments by SWMA & LVEDD (p value = <0.001). ConclusionCMR was capable of studying cardiac morphology, function myocardial viability at the same session, and is more sensitive for assessment of SWMA than echocardiography. LGE-CMR can effectively differentiate between ischemic and non-ischemic dilated cardiomyopathy on basis of myocardial scar enhancement pattern.

Effect of myocardial Scar detected by Cardiac Magnetic Resonance on perfusion time and short term outcomes after Coronary Artery Bypass Graft Surgery

Methods Patients who underwent LGE CMR between January 2003 and February 2010 <1 month prior to CABG were included. A standard 16 segment model was used for Left ventricular (LV) scar quantification. Patients were categorized into Scar group and No-scar groups. Perfusion time (PT), Cross clamp time (CCT), 30-Day mortality, Ventricular arrhythmia, duration of ventilation, prolonged ICU (ICU-LOS) and hospital stay (H-LOS) were obtained. Chi square test, ttest, Wilcoxon rank sum tests and multivariate regression analysis was used for data analysis.

Focal But Not Diffuse Myocardial Fibrosis Burden Quantification Using Cardiac Magnetic Resonance Imaging Predicts Left Ventricular Reverse Modeling Following Cardiac Resynchronization Therapy.

Many heart failure patients with dyssynchrony do not reverse remodel (RR) in response to cardiac resynchronization therapy (CRT). The presence of focal and diffuse interstitial myocardial fibrosis may explain this high nonresponse rate. T1 mapping is a new cardiac magnetic resonance imaging (CMR) technique that overcomes the limitations of conventional contrast CMR and provides reliable quantitative assessment of diffuse myocardial fibrosis. The study tested the hypothesis that focal and diffuse fibrosis quantification would correlate with a lack of left ventricular (LV) RR to CRT. In a prospective study of 48 consecutive patients (27 ischemic cardiomyopathy, 21 dilated cardiomyopathy) LV scar burdens were quantified (scar core and gray zone using late gadolinium enhancement LGE CMR; interstitial fibrosis using T1 mapping) before CRT implant. LV RR was defined by a ≥ 15% reduction in LV end-systolic volume 6 months postimplant. Twenty-seven (56%) patients were responders with RR. Association between scar quantification and LV RR was assessed using the Poisson regression model. Univariate analysis showed that QRS duration/morphology, scar core, and gray zone volumes expressed as % of LV mass and extracellular volume index (ECV) (a measure of interstitial fibrosis from T1 mapping) to be significant predictors of LV RR. Multivariable-adjusted analyses demonstrated scar core quantification (≥ 13.7% LV mass) to be the only independent predictor of LV RR (prevalence ratio 0.40, P = 0.038). Focal scar burden detected by LGE CMR is associated with a poor response to CRT. Diffuse interstitial fibrosis assessment by T1 mapping, however, is not independently predictive of CRT response.