Areas Of Late Gadolinium Enhancement Research Articles

Conditions for late gadolinium enhancement MRI in myocardial infarction model rats that better reflect microscopic tissue staining

Late gadolinium enhancement (LGE) is a widely used magnetic resonance imaging method for assessing cardiac disease. However, the relationship between different LGE signal thresholds and microscopic tissue staining images is unclear. In this study, we performed cardiovascular MRI on myocardial infarction (MI) model rats and evaluated the relationship between LGE with different signal thresholding methods and tissue staining images. We prepared 16 rats that underwent MRI 14–18 days following a surgery to create an MI model. We captured cine and LGE images of the cardiac short-axis and longitudinal two- and four-chamber views. The mean ± 2SD, ± 3SD, and ± 5SD of the pixel values in the non-infarcted area were defined as the LGE area. We compared areas of Sirius red staining, determined by the color tone, with their respective LGE areas at end-diastole and end-systole. We observed that the LGE area calculated as the mean ± 2SD of the non-infarcted area at end-diastole demonstrated a significant positive correlation with the area of Sirius red staining (Pearson’s correlation coefficient in both: 0.81 [p < 0.01]). Therefore, the LGE area calculated as the mean ± 2SD of the non-infarcted area at end-diastole best reflected the MI area in tissue staining.

Congenital Apical Left Ventricular Aneurysm.

A 17-year-old male was referred for evaluation by Pediatric Cardiology following a pre-sports medical screening, which revealed abnormal ventricular repolarization (negative T wave from V3-V6) on a 12-lead ECG. For 8 years, he has been a competitive football player. There was no relevant personal or family medical history, and he denied any prior cardiovascular symptoms. His cardiovascular physical examination was normal. In the initial assessment, a transthoracic echocardiogram was conducted, revealing an apical aneurysm of the left ventricle (LV) with regional dyskinesia, accompanied by mild mitral regurgitation. The examination also demonstrated globally preserved left ventricular systolic function, with no images suggestive of vegetations or intracardiac thrombi found. For further anatomical and myocardial characterization, a cardiac magnetic resonance (CMR) was performed. The results revealed a wide apical aneurysm of the LV, predominantly lateral, with thin walls, ridges within the outpouching, and local dyskinesia. No areas of late gadolinium enhancement (LGE) were found, suggestive of fibrosis, anomalous infiltration, or scar from a previous infarction. After excluding other etiologies, the diagnosis of a congenital ventricular aneurysm was determined. This is a very rare condition (0.12%) with a wide and variable clinical presentation, ranging from benign arrhythmias to sudden death. Various imaging techniques aid in its diagnosis, with CMR being particularly useful for excluding inflammation and cardiomyopathies, identifying LGE, and evaluating left ventricular volumes and function. There is no standard treatment, and controversy surrounds indications for surgical intervention. If a conservative approach is adopted, measures aimed at preventing endocarditis and embolism must be considered.

Effect of Cangrelor on Infarct Size in ST-Segment-Elevation Myocardial Infarction Treated by Primary Percutaneous Coronary Intervention: A Randomized Controlled Trial (The PITRI Trial).

The administration of intravenous cangrelor at reperfusion achieves faster onset of platelet P2Y12 inhibition than oral ticagrelor and has been shown to reduce myocardial infarction (MI) size in the preclinical setting. We hypothesized that the administration of cangrelor at reperfusion will reduce MI size and prevent microvascular obstruction in patients with ST-segment-elevation MI undergoing primary percutaneous coronary intervention. This was a phase 2, multicenter, randomized, double-blind, placebo-controlled clinical trial conducted between November 2017 to November 2021 in 6 cardiac centers in Singapore. Patients were randomized to receive either cangrelor or placebo initiated before the primary percutaneous coronary intervention procedure on top of oral ticagrelor. The key exclusion criteria included presenting <6 hours of symptom onset; previous MI and stroke or transient ischemic attack; on concomitant oral anticoagulants; and a contraindication for cardiovascular magnetic resonance. The primary efficacy end point was acute MI size by cardiovascular magnetic resonance within the first week expressed as percentage of the left ventricle mass (%LVmass). Microvascular obstruction was identified as areas of dark core of hypoenhancement within areas of late gadolinium enhancement. The primary safety end point was Bleeding Academic Research Consortium-defined major bleeding in the first 48 hours. Continuous variables were compared by Mann-Whitney U test (reported as median [first quartile-third quartile]), and categorical variables were compared by Fisher exact test. A 2-sided P<0.05 was considered statistically significant. Of 209 recruited patients, 164 patients (78%) completed the acute cardiovascular magnetic resonance scan. There were no significant differences in acute MI size (placebo, 14.9% [7.3-22.6] %LVmass versus cangrelor, 16.3 [9.9-24.4] %LVmass; P=0.40) or the incidence (placebo, 48% versus cangrelor, 47%; P=0.99) and extent of microvascular obstruction (placebo, 1.63 [0.60-4.65] %LVmass versus cangrelor, 1.18 [0.53-3.37] %LVmass; P=0.46) between placebo and cangrelor despite a 2-fold decrease in platelet reactivity with cangrelor. There were no Bleeding Academic Research Consortium-defined major bleeding events in either group in the first 48 hours. Cangrelor administered at the time of primary percutaneous coronary intervention did not reduce acute MI size or prevent microvascular obstruction in patients with ST-segment-elevation MI given oral ticagrelor despite a significant reduction of platelet reactivity during the percutaneous coronary intervention procedure. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03102723.

Cardiovascular magnetic resonance 3D LGE imaging for atrial fibrillation ablation

Abstract Objective To assess feasibility and reliability of cardiac magnetic resonance (CMR) imaging in visualizing left atrial (LA) structural changes that patients with paroxysmal atrial fibrillation (PAF) undergo acutely and long-term post ablation. Two different ablation methods i.e pulsed filed ablation (PFA) and cryoablation were studied. Background Pulmonary vein (PV) isolation has become the cornerstone technique for catheter ablation in patients with drug-refractory atrial fibrillation (AF). At present, almost all ablation technologies are mediated by a thermal effect. Recently, pulsed field ablation (PFA) has been introduced as a new energy source. PFA is a non-thermal ablative modality in which high voltage ultra-short pulses are applied to target tissue, while preserving the extracellular matrix architecture, nerves, and microvascular structures. Few data exist showing different structural LA changes between the two methods using Three-Dimensional (3D) Late Gadolinium Enhancement (LGE) Imaging. Methods CMR imaging was performed pre-ablation, acutely (&amp;lt;24 h), and 3 months post-ablation in 10 patients with paroxysmal atrial fibrillation (AF) undergoing pulmonary vein (PV) isolation with PFA (n = 5) or cryoablation (n = 5). 3D LGE and T2-weighted images were analysed. We obtained two data sets of 3D whole heart LGE imaging with high resolution, 20minutes post gadolinium injection. Patients underwent two acquisitions: the conventional respiratory navigated, electrocardiographically-gated 3D fast gradient echo (1.3slice thickness, 256x256 matrix acquisition) and the image-navigated isotropic high resolution 3D LGE with Dixon water-fat separation. 3D LGE data were analysed using a dedicated (ADAS LA) software in order to produce a 3D-LA model visualization of LGE areas. Results In the acute stage, LGE volume was 50% larger after PFA vs. cryoablation (P &amp;lt; 0.001), and oedema on T2 imaging was significantly smaller (visual estimation) on PFA cases. LGE rings surrounding PV ostia were more homogeneous after PFA, with no sign of microvascular damage or intramural hemorrhage as compared to cryoablation cases. In the chronic stage, the majority of acute LGE had disappeared after PFA, whereas most LGE persisted after cryo-ablation. The two 3D LGE sequences used for analysis showed complete agreement in the visualization of atrial scar with superior image quality of the novel sequence. The mean acquisition time for 3D LGE imaging was 11±4minutes for the conventional fast gradient echo sequence, and 5±2minutes for the novel 3D self-image navigated LGE sequence. Conclusions CMR imaging may help in visualization and understanding of LA structural remodeling post different ablation techniques.

CARDIOPULMONARY SUPPORT WITH EXTRACORPOREAL MEMBRANE OXYGENATION (ECMO) DURING CATHETER ABLATION OF VENTRICULAR FIBRILLATION: A CASE REPORT

Abstract The clinical case deals with a 46–year–old man, severely obese and suffering from type II diabetes mellitus and arterial hypertension, a smoker. He was admitted to our department for iterative ventricular fibrillation (VF) following a recent acute myocardial infarction with ST–segment elevation treated with percutaneous coronary angioplasty (PTCA) and implantation of drug–eluting stents on the anterior interventricular. Control coronary angiography showed good results of previous PTCA. On the echocardiogram, left ventricular pump function moderately reduced (EF 45%) with district alterations of the kinetics and aneurysmal dilatation of the ascending aorta. During hospitalization, iterative episodes of VF despite maximal antiarrhythmic therapy, promptly treated with DC shock. Continuous telemetry monitoring showed frequent early premature ventricular complex (PVC) triggering VF episodes. A 12–lead Holter ECG was performed to better identify the morphology of these PVC, documenting PVC of morphology compatible with origin from Purkinjie fibres. An electrophysiological study and mapping of the left ventricle were performed with extracorporeal membrane oxygenation (ECMO) support. During mapping of the middle left interventricular septum, VF occurred several times and was promptly treated with DC shock. In this area have been documented Purkinje fibers and low voltage and multifragmented areas; ablation was then performed by delivering radiofrequency in this area until the all potentials were completely eliminated. After ablation, no more ventricular arrhythmias were induced. Cardiac magnetic resonance imaging was performed which showed large areas of late gadolinium enhancement. The patient underwent automatic defibrillator implantation. Ventricular arrhythmias were no longer documented during telemetric monitoring. In this complex case of significant arrhythmic instability in ischemic heart disease with moderate left ventricular pump dysfunction, ECMO assistance allowed us to effectively and safely perform the ablation of the arrhythmic substrate triggering the iterative episodes of VF.

AN UNUSUAL LEFT VENTRICULAR APICAL MASS COMPLICATING ACUTE MYOCARDIAL INFARCTION

Abstract An 34–year–old man presented to the emergency department of our hospital with palpitations and presyncope. He was a smoker but had no others known cardiovascular risk factors. At admission, his electrocardiogram (ECG) showed sustained monomorphic ventricular tachycardia (VT) at a rate of 187 beats per minute. The VT was successfully treated with synchronized direct current cardioversion. The ECG in sinus rhythm showed Qs from V1 to V6 with ventricular repolarization anomalies in the same site suspicious for previous anterior necrosis. A transthoracic echocardiogram revealed akinetic apex, akinesia of middle segments of the interventricular septum, anterior and lateral walls, Left Ventricular (LV) ejection fraction of 30% and a large apical mass suspicious for LV thrombus. The patient was admitted to the coronary care unit and taken to the Cath lab that showed total left anterior descending mid–segment occlusion. Due to the chronicity of the condition, the patient was recommended to optimal medical therapy. Suspecting LV thrombus, the patient began treatment with unfractionated heparin i.v. and subsequently imbricate therapy with enoxaparin s.c. and warfarin. Additionally, the patient underwent subcutaneous implantable cardioverter defibrillator (S–ICD) implantation for secondary prevention of sudden cardiac death. At echocardiographic follow–up one week after discharge, the apical mass remained unchanged despite warfarin therapy with INR at target. For this reason, the patient was recommended to perform a Cardiovascular magnetic resonance (CMR). Three months after S–ICD implantation, a CMR was performed which showed transmural areas of late gadolinium enhancement involving all apical segments and middle segments of the interventricular septum which allowed the diagnosis of a large intramyocardial dissecting hematoma (IDH) of left ventricle. IDH is a rare complication of ST–elevation myocardial infarction (STEMI), it is an unusual form of subacute cardiac rupture and could be fatal. It usually consists of a cavity or channels within the myocardium. Its prognosis varies according to its location, but generally apical IDH have more favorable outcome with a higher likelihood of spontaneous retraction. We report this case because the IDH is a diagnostic challenge and it represents an extremely rare and poorly described event in the literature.

A RARE CASE OF INTERVENTRICULAR SEPTUM DUPLICATION

Abstract Case Report A 62–year–old man, history of hypertension. In 2015, there was suspicion of non–compaction cardiomyopathy, and he underwent cardiac MRI at another facility (report not available). The patient reported palpitations and dyspnea with exertion, leading to a follow–up visit. EKG showed sinus rhythm 90/min, nonspecific intraventricular conduction delay and isolated monomorphic ventricular ectopic beats. Echo revealed a mildly dilated left ventricle (end–diastolic volume 88 ml/m), systolic function at the lower limits of normal (EF 53%), and prominent muscular structures near the posterior interventricular septum (SIV), likely related to anomalies of the papillary muscles (prominent and possibly duplicated posterior–medial papillary muscle). There was apical trabecular protrusion, which did not meet the criteria for non–compaction (NC/C ratio in systole approximately 1), with no other significant findings. The cardiac MRI, performed to assess dilated cardiomyopathy, revealed a conspicuous structural abnormality in the septo–papillary region, located medio–apically and paraseptal–endocardial in the left ventricle. This anomaly lacked evident chordae tendineae with the mitral valve leaflets and exhibited synchronous systo–diastolic motion with the left ventricular wall, suggesting septal duplication. The septal thickness was slightly reduced, particularly in the medio–apical region. Additionally, there was hypertrabeculation of the posterior and lateral walls of the left ventricle, exceeding the threshold for non–compaction (NC/C ratio in end–diastole: 2.6 – normal range: &amp;lt;2.3). Left ventricular mass was normal (mass: 173.52 g; mass/body surface area (BSA): 86.58 g/m). Basal septum, medio–apical septum and medio–apical lateral wallshowed hypokinetic contractility. The left ventricle was dilated (end–diastolic diameter: 55.0 mm; end–systolic diameter: 45.3 mm – end–diastolic volume: 230 ml; stroke volume/BSA: 57.6 ml/m² – EF: 51%). Areas of late gadolinium enhancement (LGE) were observed in the anterior medio–basal septum and at the site of the described structural muscular anomaly, both displaying an intramural non–ischemic pattern. Conclusions The described findings suggest a picture of dilated cardiomyopathy and an associated structural septo–papillary anomaly of uncertain diagnostic interpretation (septum duplication with associated non–compacted myocardium? duplicated posterior–medial papillary muscle with associated non–compacted myocardium?).

CARDIOVASCULAR CONSIDERATIONS IN ANTIDEPRESSANT THERAPY: SINUS ARREST DUE TO SERTRALINE

Abstract A 39–year–old Caucasian woman with a silent cardiac anamnesis and no family history of cardiovascular diseases, and a history of mood disorder treated with Sertraline for about 1 month, went to the Emergency Department reporting several syncopal episode, all with rapid and complete recovery of consciousness. In the Emergency Department, another syncopal episode occurred in the supine position, characterized by sinus bradycardia evolving into a brief asystole, with spontaneous restoration of normal sinus rhythm. Admitted to the Cardiovascular Intensive Care Unit, the patient showed no abnormalities in laboratory testsas well as in echocardiography results. The patient received appropriate hydration, and home medication was discontinued. A non–contrast head CT scan showed no acute lesions. Cardiac MR revealed normal morpho–functional findings, with no evidence of myocardial edema or pericardial effusion and no pathological late gadolinium enhancement areas. Brain MRI demonstrated normal anatomical and functional findings, with no signal abnormalities. Considering the patient‘s young age and the suspicion of an iatrogenic origin of the rhythm disorder, the decision to postpone pacemaker implantation was made, and cardiac electrical activity was monitored using a loop recorder. At the one–month follow–up, the patient, who had been off Sertraline since admission, was in good health, reporting no further syncopal or pre–syncopal episodes. Loop recorder monitoring revealed no significant arrhythmias. The only relevant anamnestic data was the use of Sertraline, and the application of the Adverse Drug Reaction Probability Scale suggests that the iatrogenic origin of this event as a pharmacological adverse effect is at least probable (score: 7). Limited literature connects Sertraline directly to documented cases of asystole, but reports indicate that drugs in the same pharmacological class may induce cardiac rhythm disturbances, including tachyarrhythmias and bradyarrhythmias. This case draws attention to sinus arrest during sertraline therapy and how an appropriate pharmacological washout led to the resolution of the pathology.

Serial Cardiac Magnetic Resonance Imaging in Patients with Mitral Valve Prolapse-A Single-Center Retrospective Registry.

Background: Mitral valve prolapse (MVP) and mitral annular disjunction (MAD) are common valvular abnormalities that have been associated with ventricular arrhythmias (VA). Cardiac magnetic resonance imaging (CMR) has a key role in risk stratification of VA, including assessment of late gadolinium enhancement (LGE). Methods: Single-center retrospective analysis of patients with MVP or MAD who had >1 CMR and >1 24 h Holter registration available. Data are presented in detail, including evolution of VA and presence of LGE over time. Results: A total of twelve patients had repeated CMR and Holter registrations available, of which in four (33%) patients, it was conducted before and after minimal invasive mitral valve repair (MVR). After a median of 4.7 years, four out of eight (50%) patients without surgical intervention had new areas of LGE. New LGE was observed in the papillary muscles and the mid to basal inferolateral wall. In four patients, presenting with syncope or high-risk non-sustained ventricular tachycardia (VT), programmed ventricular stimulation was performed and in two (50%), sustained monomorphic VT was easily inducible. In two patients who underwent MVR, new LGE was observed in the basal inferolateral wall of which one presented with an increased burden of VA. Conclusions: In patients with MVP and MAD, repeat CMR may show new LGE in a small subset of patients, even shortly after MVR. A subgroup of patients who presented with an increase in VA burden showed new LGE upon repeat CMR. VA in patients with MVP and MAD are part of a heterogeneous spectrum that requires further investigation to establish risk stratification strategies.

Myocardial inflammation in Fabry disease: correlations between myocardial histology, T2 mapping, and troponin

Abstract Background Myocardial inflammation likely plays a key role in cardiac Fabry disease (FD), supported by the frequent observation using cardiac MRI (CMR) of high T2 mapping values, mainly in areas of late gadolinium enhancement, LGE), typically representing oedema, and increased troponin (myocardial injury). Purpose To characterize inflammation in FD cardiomyopathy by comparing myocardial histology, T2 mapping and troponin. Methods Fifteen FD patients (67% females; 51 years old, range 39-62), undergoing 3 tests: biopsy (either RV endomyocardial biopsy, n=10, or myectomy, n=5); CMR (1.5T: cines, LGE, native T1/T2 mapping quantified in the sampling area); and troponin assessment (high sensitivity TnI). Mapping values were compared to local healthy volunteers. Left ventricle hypertrophy (LVH) was defined as either MWT ≥12mm or indexed LV mass above sex specific reference ranges. Tissue was stained using Haematoxylin-Eosin and Azan Mallory trichrome. Inflammatory cell staining used CD68 and CD3 antibodies. An abnormal inflammatory infiltrate was defined according to ESC criteria as ≥14 leukocytes/mm2 (up to 4monocytes/mm2, CD3+T-lymphocytes&amp;gt;7cells/mm2) and its distribution classified as focal (&amp;lt;30% of the specimen), multifocal (30-60%), diffuse (&amp;gt;60%). Results Median LV ejection fraction was 63% (58-67); indexed end diastolic volume 83ml/m2 (68-91). Seven patients had LVH. 8 patients had low native T1 and 6 had infero-lateral LGE. Median septal T2 value was 50ms (47-52) with 3 (all females) above local upper limit value (ULV). TnI was increased in 6 pts (40%; median value 54ng/L [38-128]). Histology showed mild inflammatory infiltrates in 8 pts (46%), none diffuse (focal 4, multifocal 4). Seven were mixed - T lymphocytes and macrophages, one was exclusively macrophages. Inflammatory foci were quiescent (n=5), or associated to myocytes injury not typical of ischemic damage and fibrosis (n=3). None had histologically visible myocardial oedema. Patients with inflammatory infiltrates had higher T2 values (52ms [50-54] vs 47ms [46-51]; p=0.043) but the same troponin (18ng/L [3-82] vs 14ms [3-24], p=0.215) (figure 1). The 3 patients with high T2 all had inflammatory cells associated to histologic myocyte injury (figure 2). Conclusion For the first time we correlate histology with T2 and myocardial injury in FD. In this small study, mild myocardial macrophage/lymphocyte infiltrates are common in FD and are associated to higher T2 values. Abnormal T2 septal elevation is less common (it is known common in the basal inferolateral wall however) and when present, infiltration with histological myocyte damage is found.

Incremental prognostic value of late gadolinium enhancement extent, transmurality, and pattern in patients with ischaemic cardiomyopathy

Abstract Background Presence and extent of late gadolinium enhancement (LGE) using cardiac magnetic resonance (CMR) are strong prognosticators of outcomes in ischaemic cardiomyopathy (ICM), but the prognostic value of multiple location of LGE, LGE transmurality, and midwall LGE area in addition to ischaemic LGE is not well established. Purpose To assess the incremental prognostic value of presence, extent, transmurality, and pattern of LGE in patients with ICM and reduced left ventricular ejection fraction (LVEF)­­. Methods Between 2008 and 2022, all consecutive patients referred for myocardial viability assessment using CMR and a history of ICM (≥70% stenosis in ≥1 epicardial coronary vessel on angiography and/or history of myocardial infarction and/or coronary revascularization) and LVEF value &amp;lt;50% were prospectively recruited. The outcome was all-cause death using the electronic French National Registry of Death. Nested Cox proportional hazard models were used to assess the prognostic value of the following LGE features: the extent, the transmurality of subendocardial ischaemic LGE (&amp;lt;50%, ≥50%, or transmural), the presence of LGE in multiple areas, and the presence of midwall LGE. The additional predictive value of the LGE features was assessed by the C-statistic increment, the continuous net reclassification improvement (NRI), the integrative discrimination index (IDI) and the global Chi-2. Results Among the 6,082 included patients (mean age 65±12 years, 73% male, mean LVEF 43.8±5.7%), 3,591 (59%) had ischaemic LGE; 652 (10.7%) patients died during a median follow up of 9 [6.6-11.5] years. After adjustment for risk factors in the overall population, the presence of ischaemic LGE was associated with a higher risk of death (adjusted HR=3.57; 95%CI: 2.89-4.40, p&amp;lt;0.001). Figure 1 shows survival according to the different LGE features. Patients with both multiple localisations of ischaemic LGE area and additional LGE midwall exhibited the highest risk of death (p&amp;lt;0.001). After adjustment in the subgroup of patients with ischaemic LGE (n=3,591), LGE extent (HR=1.55; 95%CI: 1.47-1.63), multiple localisations of ischaemic LGE (HR 1.61 95%CI: 1.32-1.97), LGE transmurality (HR=4.48; 95%CI: 3.39-5.93), and presence of additional midwall LGE (HR=1.77; 95%CI: 1.44-2.17, all p&amp;lt;0.001) were independently associated with a higher risk of death. A model combining all LGE features showed the best improvement in model discrimination and reclassification above traditional factors (C-statistic improvement: 0.17; NRI=54.1%; IDI=12.6%, Chi-2 global=1133, all p&amp;lt;0.001; LR-test p&amp;lt;0.001, Figure 2). Conclusion In a large cohort of ICM patients with reduced LVEF, ischaemic LGE extent, transmurality, multiple ischaemic LGE localisations, and additional presence of midwall LGE were independent prognosticators of death. A model combining all these LGE features had an incremental prognostic value over traditional prognostic factors to predict all-cause death.Kaplan-Meier survival curvesIncremental prognostic value

Abstract 16631: Isolated Cardiac Sarcoidosis Presenting as Recurrent Transient Ischemic Attacks

Background: Cardiac sarcoidosis (CS) is a rare disease that can present with a variety of clinical scenarios including, heart failure and sudden death. We present a case of isolated CS presenting as recurrent transient ischemic attacks (TIA) in a previously asymptomatic patient. Description of Case. A 54-year-old female with a history of two previous TIAs presented 30 minutes after the onset of left-sided facial droop and incomprehensible speech. CT and MRI brain did not show acute infarction. ECG showed a right bundle branch block pattern. Transthoracic echocardiogram (TTE) showed an abnormal global longitudinal strain of 12.8%, a left ventricular ejection fraction of 40%, segmental wall motion abnormalities involving the apex and basal inferior walls, and swirling of contrast at the apex. She had no previous history of cardiomyopathy. CTA was unrevealing for coronary artery disease but a cardiac MRI showed areas of late gadolinium enhancement and a RV wall aneurysm. PET scan revealed multifocal patchy nodular areas of FDG uptake within the myocardium. A diagnosis of isolated CS was made. At a three-month follow-up, TTE showed a new apical thrombus measuring 0.8cm x 0.6 cm. The patient was started on anticoagulation with the eventual resolution of the thrombus. She had no further ischemic events. Discussion. TIAs and ischemic stroke are extremely rare complications of CS and are largely attributed to cardioembolic phenomena, in the absence of systemic disease. Cardiac structural changes that lead to arrhythmias, hypokinesis, and stasis with clot formation largely explain embolic events in these patients. In addition, evidence suggests that the inflammatory cytokines, such as IFN gamma and IL-12, released by the sarcoid granuloma may also have an independent role in clot formation. The combination of stagnant flow in akinetic areas and a strong inflammatory bed of cytokines led to recurrent TIAs in this patient and the apical thrombus that was later identified.

Abstract 13584: Prognostic Value of Combined Assessment of Cardiac Magnetic Resonance and Fluorodeoxyglucose Positron Emission Tomography in Patients With Cardiac Sarcoidosis

Background: Although the combined assessment of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) and 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) was useful for the detection of cardiac sarcoidosis (CS), its prognostic value remains unclear. Methods: We examined 90 consecutive CS patients diagnosed by both CMR and FDG-PET before prednisolone (PSL) therapy between September 2008 and April 2023 in our hospital. We calculated the overlap rate of FDG uptake area in the LGE-positive area to evaluate the association between concordance of FDG/LGE areas and adverse events. Patients were divided into two groups according to the median concordance ratio (overlap rate) between FDG and LGE areas (70 %). The primary outcome was a composite of sustained ventricular tachycardia/fibrillation (VT/VF), worsening heart failure, and sudden cardiac death. Results: Median interval between CMR and FDG-PET was 6.5 (IQR 3.0-24.0) days. There are no significant differences on age, sex, left ventricular ejection fraction (LVEF), brain natriuretic peptide (BNP) level, and extent of LGE between the groups. During a median follow-up period of 3.2 (IQR 1.0-6.2) years, the primary outcome occurred in 25 (28%) patients. Patients with lower concordance showed a higher incidence of the primary outcome (Figure A), and lower improvement in LVEF after PSL therapy (Figure B) compared to those with higher concordance. In multivariable Cox regressions, lower concordance was significantly associated with the primary outcome adjusted for history of VT/VF (HR 7.37, P = 0.001), LVEF (HR 7.75, P = 0.001), log BNP (HR 5.62, P = 0.006), and extent of LGE (HR 11.75, P = 0.017). Conclusions: Lower concordance ratio of FDG/LGE before PSL therapy was associated with higher incidence of adverse events and lower improvement of LVEF. Assessment of active inflammation in the extent of LGE might be useful for risk stratification and prediction of the response to PSL in patients with CS.

Detection of sympathetic denervation defects in Fabry disease by hybrid [11C]meta-hydroxyephedrine positron emission tomography and cardiac magnetic resonance

BackgroundMyocardial glycosphingolipid accumulation in patients with Fabry disease (FD) causes biochemical and structural changes. This study aimed to investigate sympathetic innervation in FD using hybrid cardiac positron emission tomography (PET)/magnetic resonance imaging (MRI). Methods and resultsPatients with different stages of Fabry disease were prospectively enrolled to undergo routine CMR at 1.5T, followed by 3T hybrid cardiac PET/MRI with [11C]meta-hydroxyephedrine ([11C]mHED). Fourteen patients with either no evidence of cardiac involvement (n = 5), evidence of left ventricular hypertrophy (LVH) (n = 3), or evidence of LVH and fibrosis via late gadolinium enhancement (LGE) (n = 6) were analyzed. Compared to patients without LVH, patients with LVH or LVH and LGE had lower median T1 relaxation times (ms) at 1.5 T (1007 vs. 889 vs. 941 ms, p = 0.003) and 3T (1290 vs. 1172 vs. 1184 p = .014). Myocardial denervation ([11C]mHED retention < 7%·min) was prevalent only in patients with fibrosis, where a total of 16 denervated segments was found in two patients. The respective area of denervation exceeded the area of LGE in both patients (24% vs. 36% and 4% vs. 32%). However, sympathetic innervation defects ([11C]mHED retention ≤ 9%·min) occurred in all study groups. Furthermore, a reduced sympathetic innervation correlated with an increased left ventricular mass (p = .034, rs = − 0.57) and a reduced global longitudinal strain (GLS) (p = 0.023, rs = − 0.6). ConclusionHybrid cardiac PET/MR with [11C]mHED revealed sympathetic innervation defects, accompanied by impaired GLS, in early stages of Fabry disease. However, denervation is only present in patients with advanced stages of FD showing fibrosis on CMR.

Differences in Atrial Substrate Localization using LGE-MRI, Electrogram Voltage and Conduction Velocity - A Cohort Study Using a Consistent Anatomical Reference Frame in Patients with Persistent Atrial Fibrillation.

Electro-anatomical voltage, conduction velocity (CV) mapping and late gadolinium enhancement magnetic resonance imaging (LGEMRI) have been correlated with atrial cardiomyopathy (ACM). However, the comparability between these modalities remains unclear. Aims: (1) Compare pathological substrate extent and location between current modalities. (2) Establish spatial histograms in a cohort. (3) Develop a new estimated optimised image intensity threshold (EOIIT) for LGE-MRI identifying patients with ACM. (4) Predict rhythm outcome after pulmonary vein isolation (PVI) for persistent atrial fibrillation. 36 ablation-naive persistent AF patients underwent LGE-MRI and high-definition electro-anatomical mapping in SR. LGE areas were classified using the UTAH, image intensity ratio (IIR > 1.20) and new EOIIT method for comparison to LVS and slow conduction areas <0.2 m/s. ROC analysis was used to determine LGE thresholds optimally matching LVS. ACM was defined as low voltage substrate (LVS) extent ≥ 5% of the left atrium (LA) surface at <0.5 mV. The degree and distribution of detected pathological substrate varied significantly (p < 0.001) across the mapping modalities: 3% (IQR 0-12%) of the LA displayed LVS < 0.5 mV vs. 14% (3-25%) slow conduction areas < 0.2 m/s vs. 16% (6-32%) LGE with the UTAH method vs. 17% (11-24%) using IIR > 1.20, with most discrepancies on the posterior LA. Optimised image intensity thresholds and each patient's mean blood pool intensity correlated linearly (R2 = 0.89, p < 0.001). Concordance between LGE-MRI-based and LVS-based ACM diagnosis improved with the novel EOIIT applied at the anterior LA (83% sensitivity, 79% specificity, AUC: 0.89) in comparison to the UTAH method (67% sensitivity, 75% specificity, AUC: 0.81) and IIR > 1.20 (75% sensitivity, 62% specificity, AUC: 0.67). Discordances in detected pathological substrate exist between LVS, CV and LGE-MRI in the LA, irrespective of the LGE detection method. The new EOIIT method improves concordance of LGE-MRI-based ACM diagnosis with LVS in ablation-naive AF patients but discrepancy remains particularly on the posterior wall. All methods may enable prediction of rhythm outcome after PVI in patients with persistent AF.

P105: Pre-Emptive Use of Mechanical Circulatory support in sudden cardiac death- A contrasting case series

Life-threatening ventricular tachycardia(VT) and fibrillation(VF) are the most important causes of sudden cardiac death(SCD). Patients who survive are often predisposed to recurrent VT secondary to scar tissue and require definitive ablation therapies. However given the unpredictable nature of arrhythmias, patients can degenerate into VT storm even as outpatient and become hemodynamically unstable which precludes ablation therapies. Using preemptive mechanical circulatory support in such patients as a bridge to ablation can be a game changer, especially in the event of a fresh VT. We present two contrasting cases, where preemptive use of Impella showed better outcomes in neurological status post cardiac arrest. Our patient is a 16-year-old competitive basketball player who suffered an out-of-hospital VT arrest during match practice requiring bystander CPR and multiple shocks. He was stabilized in an outside hospital and brought to us intubated, paralyzed, on multiple pressors and maintained on IV amiodarone and lidocaine. ECHO demonstrated a very large right ventricle (RV) with severe left ventricle(LV) dysfunction, ejection fraction(EF) 10-15% with basal RV diameter 6.8cm. Cardiac MRI(CMRI) showed an area of late gadolinium enhancement (LGE) of the RV-free wall near the apex. Endomyocardial biopsy, Cardiac catheterization, and CT angiogram were unremarkable. With improvement in volume status, he was weaned off all inotropes and antiarrhythmics, received an AICD, and maintained only on sotalol and lisinopril. On outpatient follow-up, repeat CMRI confirmed Arrhythmogenic RV dysplasia. Unfortunately, four months later, the patient had another episode of cardiac arrest secondary to a VT storm with 20 minutes of downtime. He was deemed too unstable for VT ablation and thus emergently underwent a stellate ganglion block. The patient remained encephalopathic post-cardiac arrest with very slow neurologic recovery. He subsequently underwent cardiac transplantation The second case is that of a 63-year-old male with a past medical history of nonischemic cardiomyopathy with LVEF of 10% status post-ICD placement, and VT on amiodarone who presented with episodes of monomorphic VT followed by ICD shocks and syncope. Heart catheterization showed diffuse three-vessel disease. Due to recurrent VT patients, he received an Impella CP as a bridge to VT ablation. Interestingly during ablation, the patient goes into cardiac arrest requiring CPR for 90 minutes. He had successful VT ablation and with no neurological deficit post-procedure. Multiple trials have shown an improved 30-day survival rate without neurological sequelae with early implantation of Impella during ongoing CPR for cardiac arrest. Impella has several favorable properties by unloading the LV which limits the infarct size and maintains cerebral perfusion during the arrest. Preemptive Impella use is often used as a bridge to transplant, however using it as a bridge to ablation is yet to gain prominence.

Arrhythmic Mitral Valve Prolapse With Only Mild or Moderate Mitral Regurgitation: Characterization of Myocardial Substrate

BackgroundSustained ventricular tachycardia and sudden cardiac death due to degenerative mitral valve prolapse (MVP) can occur in the absence of severe mitral regurgitation (MR). A significant percentage of patients with MVP-related sudden death do not have any evidence of replacement fibrosis, suggesting other unrecognized proarrhythmic factors may place these patients at risk. ObjectivesThis study aims to characterize myocardial fibrosis/inflammation and ventricular arrhythmia complexity in patients with MVP and only mild or moderate MR. MethodsProspective observational study of patients with MVP and only mild or moderate MR underwent ventricular arrhythmia characterization and hybrid positron emission tomography (PET)/magnetic resonance imaging (MRI). Coregistered hybrid 18F-fluorodeoxyglucose (18F-FDG)–PET and MRI late gadolinium enhancement images were assessed and categorized. Recruitment occurred in the cardiac electrophysiology clinic. ResultsIn 12 patients with degenerative MVP with only mild or moderate MR, of which a majority had complex ventricular ectopy (n = 10, 83%), focal (or focal-on-diffuse) uptake of 18F-FDG (PET-positive) was detected in 83% (n = 10) of patients. Three-quarters of the patients (n = 9, 75%) had FDG uptake that coexisted with areas of late gadolinium enhancement (PET/MRI-positive). Abnormal T1, T2 and extracellular volume (ECV) values were observed in 58% (n = 7), 25% (n = 3), and 16% (n = 2), respectively. ConclusionsMost patients with degenerative MVP, ventricular ectopy, and mild or moderate MR show myocardial inflammation that is concordant with myocardial scar. Further study is needed to determine whether these findings contribute to the observation that most MVP-related sudden deaths occur in patients with less than severe MR.

P37 MULTIMODALITY DIAGNOSTIC APPROACH TO A JUVENILE CASE OF SUSTAINED VENTRICULAR TACHYCARDIA

Abstract Clinical case 31–year–old male subject, former competitive athlete, with family history of coronary artery disease and no further cardiovascular risk factors or previous cardiac events. Previous SARS–CoV2–related paucisymptomatic infection (January 2022) and subsequent episode of fever (August 2022) with negative SARS–CoV2 nasal swab. In September 2022 he reported sudden onset of palpitations after hearty meal. Because of such symptoms, the patient underwent Holter ECG showing 90 episodes of ventricular tachycardia (VT) and one episode of sustained VT. Based on such evidence, the patient went to the emergency room (ER). During the ER stay, blood exams (blood count, high–sensitivity troponin, BNP, CRP, D–dimer) and ECG were normal and SARS–CoV2 test was negative. The patient was then hospitalized in cardiac ICU. The echocardiogram showed left ventricle with normal dimension, thickness and wall motion (EF: 65%, mean GLS: –20%), trivial mitral and aortic regurgitation, no pericardial effusion. Subsequently, a cardiac coronary CT scan was performed showing absence of atherosclerotic lesions and myocardial bridge of the middle segment of LAD artery. The diagnostic pathway went on with cardiac magnetic resonance (CMR) demonstrating focal hypokinesia and wall thickness reduction of the anteroseptal–anterior junctional wall at middle–distal level (minimum thickness: 3 mm) where a millimetric area of late gadolinium enhancement with transmural distribution was described; absence of myocardial oedema. In addition, an EPS was performed with electroanatomical high–density/definition mapping of the left ventricle showing normal volumes, signals and activation and absence of LAVA/LV. Taking into account such findings, a subcutaneous defibrillator was implanted for primary prevention and a control CMR was scheduled in the follow–up period. Conclusions This case underlines the central role of CMR in identifying areas of myocardial fibrosis that can represent the electroanatomical substrate for triggering ventricular arrhythmias. In this case, the arrhythmic events are associated with a focal area of transmural fibrosis and wall thinning, usually indicating ischaemic damage, nonetheless in the presence of normal coronary arteries.

Cardiovascular magnetic resonance findings in Danon disease: a case series of a family.

Cardiac involvement constitutes the primary cause of mortality in patients with Danon disease (DD). This study aimed to explore the cardiac magnetic resonance (CMR) features and progressions of DD cardiomyopathies in a family with long-term follow-up. Seven patients (five females and two males), belonging to the same family and afflicted with DD, were enrolled in this study between 2017 and 2022. The cardiac structure, function, strain, tissue characteristics on CMR and their evolutions during follow-up were analyzed. Three young female patients (3/7, 42.86%) exhibited normal cardiac morphology. Four patients (4/7, 57.14%) displayed left ventricle hypertrophy (LVH), and mostly with septal thickening (3/4, 75%). A single male case (1/7, 14.3%) showed decreased LV ejection fraction (LVEF). Nonetheless, the global LV strain of the four adult patients decreased in different degree. The global strain of adolescent male patients was decreased compared to the age-appropriate female patients. Five patients (5/7, 71.43%) exhibited late gadolinium enhancement (LGE), with proportion ranging from 31.6% to 59.7% (median value 42.7%). The most common LGE location was the LV free wall (5/5, 100%), followed by right ventricle insertion points (4/5, 80%) and intraventricular septum (2/5, 40%). Segmental radial strain (rs = -0.586), circumferential strain (r = 0.589), and longitudinal strain (r = 0.514) were all moderately correlated with the LGE proportions of corresponding segments (P < 0.001). T2 hyperintense and perfusion defect foci were identified, overlapping with the LGE areas. During follow-up, both the young male patients exhibited notable deterioration of their cardiac symptoms and CMR. The LVEF and strain decreased, and the extent of LGE increased year by year. One patient underwent T1 mapping examination. The native T1 value was sensitively elevated even in regions without LGE. Left ventricular hypertrophy, LGE with sparing or relatively less involved IVS, and LV dysfunction are prominent CMR features of Danon cardiomyopathy. Strain and T1 mapping may have advantages in detecting early-stage dysfunction and myocardial abnormalities in DD patients, respectively. Multi-parametric CMR can serve as an optimal instrument for detecting DD cardiomyopathies.

Right ventricular-dominant transthyretin deposition: an early stage or a rare phenotype of wild-type transthyretin amyloid cardiomyopathy?

An 86-year-old Japanese man was referred to our hospital because of leg oedema. Electrocardiography revealed a right bundle branch block, and transthoracic echocardiography showed a left ventricular septal wall thickness of 15 mm. On cardiovascular magnetic resonance imaging (CMR), late gadolinium enhancement areas and high native T1 value areas extended in the basal region of the left ventricular lateral wall (Panels A and C), the right ventricular (RV) side of the septum, and the RV free wall (Panels B and D). Abnormal accumulation of 99mTc-labelled pyrophosphate (99mTc-PYP) in the myocardium was visualized in concordance with the abnormal areas on CMR (Panels E and F). The patient was diagnosed with wild-type transthyretin amyloid cardiomyopathy (ATTR-CM) due to the histological evidence of transthyretin deposition in the myocardium and no transthyretin gene mutation. In this case, both CMR and 99mTc-PYP scintigraphy, which are reliable imaging tools for transthyretin deposition in the myocardium, revealed RV-dominant transthyretin deposition. Based on the UK ATTR-CM staging system, this case was classified as Stage 1. Since no cases of RV-dominant transthyretin deposition have been reported in the literature, it is unclear whether RV-dominant transthyretin deposition is an early stage or a very rare clinical phenotype of wild-type ATTR-CM. Nonetheless, clinicians should be aware of an RV-dominant transthyretin deposition pattern in wild-type ATTR-CM.