Late Gadolinium Enhancement Burden Research Articles

Intravenous immunoglobulin does not reduce burden of late gadolinium enhancement in pediatric patients with myocarditis: A pilot study

Intravenous immunoglobulin does not reduce burden of late gadolinium enhancement in pediatric patients with myocarditis: A pilot study

Revisiting risk stratification in hypertrophic cardiomyopathy after the recent guidelines - LGE remains tough to beat

Abstract Background and Objectives Over the last decades, the recommendation for ICD implantation for the primary prevention of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) has been evolving. Late gadolinium enhancement (LGE) has been incorporated in the guidelines as a risk factor to be considered for ICD implantation. The aims of this study were: 1) assess the evolution of accuracy and discriminative ability of the different guidelines (ESC 2014, ESC 2022, ESC 2023, ACC 2011 and ACC 2020) in predicting SCD; and 2) to understand whether LGE can further help in the risk stratification of SCD. Methods We conducted an international multicentric retrospective analysis of HCM patients undergoing cardiac magnetic resonance (CMR) for diagnostic confirmation and/or risk stratification. Eligibility criteria for ICD according to the ESC 2014 (HCM), ESC 2022 (Ventricular arrhythmias VAs), ESC 2023 (Cardiomyopathies), ACC 2011 and ACC 2020 (both HCM guidelines) was determined for each patient. Our primary endpoint was a composite of SCD, appropriate ICD discharge and sustained VT. Results We included a total of 530 patients (median age was 49 (IQR 35-61), 57% male). Over a median follow-up of 3.8 (IQR 1.6 – 7.0) years, 27 events occurred (13 SCDs, 8 appropriate ICD discharges and 6 sustained VAs). The diagnostic accuracy statistics of the European and the American societies guidelines have evolved similarly over time: sensitivity and PPV increased, NPV remained high and discriminative ability also increased (see Figure). However, the concordance in risk assessment is only moderate between the ESC 2022 and ACC 2020 (κ = 0.60 (95%CI: 0.54–0.67); p < 0.001) or the ESC 2023 and ACC 2020 guidelines (κ = 0.56 (95%CI: 0.49–0.62); p < 0.001). LGE was present in 80% of patients. Median LGE% was 3.2% (IQR 0.5 – 8.4%) and remained an independent predictor of arrhythmic events after adjustment to known confounders (aHR of 1.09 per 1% increase in LGE% [95% CI 1.05 – 1.12; p < 0.001]). The Youden test showed a best cut-off for LGE burden of 7.1%. Further risk stratification could be reached by employing LGE% as an arbiter. Irrespectively of the guideline publisher, in patients with any recommendation for ICD (classes IIa and IIb), the absence of LGE identified patients with no arrhythmic events during follow-up (see Figure). Conclusions Current guidelines have shown increased sensitivity, PPV and discriminative power when compared with older counterparts. LGE burden remains an independent risk factor for arrhythmic events and although extensive LGE burden has been included in the risk stratification for ICD implantation, further stratification can be accomplished for ICD recommendation, since this seems to be a predictor stronger than clinical parameters.

Myocardial Scarring and Sudden Cardiac Death in Young Patients With Hypertrophic Cardiomyopathy

The ability to predict sudden cardiac death (SCD) in children and adolescents with hypertrophic cardiomyopathy (HCM) is currently inadequate. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) imaging is associated with SCD events in adults with HCM. To examine the prognostic significance of LGE in patients with HCM who are younger than 21 years. This multicenter, retrospective cohort study was conducted from April 8, 2015, to September 12, 2022, in patients with HCM who were younger than 21 years and had undergone CMR imaging across multiple sites in the US, Europe, and South America. Observers of CMR studies were masked toward outcomes and demographic characteristics. Natural history of HCM. The primary outcome was SCD and surrogate events, including resuscitated cardiac arrest and appropriate discharges from an implantable defibrillator. Continuous and categorical data are expressed as mean (SD), median (IQR), or number (percentage), respectively. Survivor curves comparing patients with and without LGE were constructed by the Kaplan-Meier method, and likelihood of subsequent clinical events was further evaluated using univariate and multivariable Cox proportional hazards models. Among 700 patients from 37 international centers, median (IQR) age was 14.8 (11.9-17.4) years, and 518 participants (74.0%) were male. During a median (IQR) [range] follow-up period of 1.9 (0.5-4.1) [0.1-14.8] years, 35 patients (5.0%) experienced SCD or equivalent events. LGE was present in 230 patients (32.9%), which constituted an mean (SD) burden of 5.9% (7.3%) of left ventricular myocardium. The LGE amount was higher in older patients and those with greater left ventricular mass and maximal wall thickness; patients with LGE had lower left ventricular ejection fractions and larger left atrial diameters. The presence and burden of LGE was associated with SCD, even after correcting for existing risk stratification tools. Patients with 10% or more LGE, relative to total myocardium, had a higher risk of SCD (unadjusted hazard ratio [HR], 2.19; 95% CI, 1.59-3.02; P < .001). Furthermore, the addition of LGE burden improved the performance of the HCM Risk-Kids score (before LGE addition: 0.66; 95% CI, 0.58-0.75; after LGE addition: 0.73; 95% CI, 0.66-0.81) and Precision Medicine in Cardiomyopathy score (before LGE addition: 0.68; 95% CI, 0.49-0.77; after LGE addition: 0.73; 95% CI, 0.64-0.82) SCD predictive models. In this retrospective cohort study, quantitative LGE was a risk factor for SCD in patients younger than 21 years with HCM and improved risk stratification.

Clinical and cardiovascular magnetic resonance profile of cardiomyopathy patients from South Africa: Pilot of the IMHOTEP study

Cardiomyopathy is an important cause of heart failure, however, there is notable lack of data on causes and manifestations of cardiomyopathy in Africa. The African Cardiomyopathy and Myocarditis Registry Program (IMHOTEP) aims to address the knowledge gap on etiology, treatment, and outcomes of cardiomyopathy in sub-Saharan Africa. We conducted a single-center pilot study to delineate the clinical and cardiovascular magnetic resonance (CMR) phenotypes of cardiomyopathy in South African patients. Assessment of the first 99 adult incident cases [mean age 36.8±12.5years; females 53.5%] enrolled in IMHOTEP showed that dilated cardiomyopathy (n=77) was commonest, followed by hypertrophic (n=13), restrictive (n=5) and arrhythmogenic (n=4) cardiomyopathies. A broad range of etiologies were encountered with secondary causes identified in 42% of patients. Onset of symptoms in the peripartum period was observed in 47% of women, and peripartum cardiomyopathy was diagnosed in 32.1% of women recruited. In addition to electrocardiography and echocardiography, CMR was performed in 67 cases and contributed diagnostically in a third of cases. Acute inflammation was rarely observed [2%] on CMR, however, late gadolinium enhancement (LGE) was noted in 92% of cases. We report a diverse spectrum of causes of cardiomyopathy in the South African population, with secondary, potentially treatable, etiologies in a significant proportion of cases. CMR was useful in delineating specific phenotypes and etiologies, influencing clinical care. A higher-than-expected burden of LGE was observed in this young patient cohort - the implications of which are yet to be determined.

Abstract 18159: Cardiac Resynchronization Therapy Response Predicted by Tissue Characterization Using Cardiac Magnetic Resonance Imaging in Non-Ischemic Dilated Cardiomyopathy

Introduction: Tissue characterization using cardiac magnetic resonance (CMR) is helpful for risk stratification in non-ischemic dilated cardiomyopathy (NIDCM). Hypothesis: This study aimed to investigate the predictive role of tissue characterization identified by CMR on cardiac resynchronization therapy (CRT) response. Methods: We retrospectively reviewed the patients who underwent CMR within 1 year before CRT implantation in NIDCM patients at a single tertiary center from January 2018 to September 2022. Late gadolinium enhancement (LGE), native T1, T2 and extracellular volume (ECV) were analyzed. CRT response was defined as a decrease in left ventricular end-systolic volume (LVESV) &gt; 15% or an increase in left ventricular ejection fraction &gt; 5% on TTE after at least 3 months after CRT implantation. Results: Among a total of 101 patients (mean age 66 years, 52.5% of male), 76 (75.2%) patients were defined as CRT responders. CRT responders had more LBBB (96.1% vs. 60.0%, p&lt;0.001) and longer QRS duration (156.0±178.5 vs. 167.0±176.5ms, p=0.005) compared with CRT non-responders. However, LGE burden (34.3 vs. 13.3%, p&lt;0.001), native T1 (1371.6 vs. 1336.8ms, p=0.033), T2 (45.9 vs. 42.1ms, p&lt;0.001), and extracellular volume (ECV, 36.8 vs. 31.0%, p&lt;0.001) were significantly higher in CRT non-responders. The area under the curve (AUC) to predict CRT response is the highest in LGE burden (0.817, 95% confidence interval [CI]: 0.710-0.925), followed by ECV (0.808, 95% CI: 0.711-0.905), T2 (0.779, 95% CI: 0.663-0.895), and native T1 (0.643, 95% CI: 0.520-0.766). After adjustment, LGE burden&gt;20% (odds ratio [OR]: 0.15, 95% CI: 0.02-0.71, p=0.024) and ECV &gt; 34% (OR: 0.13, 95% CI: 0.01-0.78, p=0.037) were independently poor CRT response predictors. Conclusions: The tissue characterization by using CMR is helpful to predict CRT response and clinical outcomes in patients with NIDCM, independently of conventional CRT response predictors.

Abstract 11836: A Rare Cause of Recurrent Myocardial Infarction: Genetic Testing Cracks the Case

A 29-year-old man presented to our institution with acute, severe substernal chest pain. An ECG on arrival revealed 3mm ST-elevations in the lateral leads with reciprocal depressions in the inferior leads. Troponin-I was above assay (&gt;50 ng/mL). Emergent coronary angiography showed normal coronary arteries, and left ventriculogram showed no wall motion abnormalities. A transthoracic echocardiogram showed normal biventricular size, wall thickness, and ejection fraction (EF). This was his fifth episode of chest pain over the past 10 years, consistent with prior presentations of ST-elevation myocardial infarction and angiographically normal coronary arteries. A prior cardiac magnetic resonance imaging (MRI, 6 years before the current presentation) revealed increased T2 signal intensity and subepicardial late gadolinium enhancement (LGE) in the septum, inferior, and inferolateral walls, suggestive of nonischemic acute myocardial injury. A repeat cardiac MRI during the current presentation showed mildly reduced biventricular systolic function (LVEF 52%, RVEF 36%), and again showed increased T2 signal intensity and subepicardial LGE involving the septum, inferior and inferolateral walls. The anterior and anterolateral walls were also now involved. Endomyocardial biopsy (EMB) showed focal interstitial fibrosis with no evidence of active myocarditis. On telemetry he was noted to have runs of non-sustained ventricular tachycardia (NSVT). Serologic evaluation was negative for parvovirus, cytomegalovirus, and Chagas disease. Erythrocyte sedimentation rate and C-reactive protein levels were normal. Genetic testing was performed at our newly established cardiovascular genetics program, which showed a pathogenic truncating mutation in the desmoplakin gene (DSP). DSP cardiomyopathy (CM) is an LV-predominant arrhythmogenic CM, which can present with episodic myocardial injury, and has a high disposition for ventricular arrhythmias with subepicardial LGE pattern often proceeding LV systolic dysfunction. A primary prevention implantable cardioverter-defibrillator was placed given extent of LGE and NSVT burden in the context of DSP variant. This case illustrates the importance of genetic testing in identifying rare CM phenotypes.

Incidence and Predictors of Relapse After Weaning Immune Suppressive Therapy in Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is a relapsing-remitting disease, and immune suppression (IS) is the mainstay of therapy. Predictors of relapse for patients with CS in remission are not well characterized. We assessed incidence of relapse in consecutive patients with CS treated with high-dose steroids and/or steroid-sparing agents (SSA) in our center from 2000 to 2020. Remission was defined as reaching maintenance therapy (no IS, SSA, and/or prednisone ≤5mg/d) for ≥1month. Relapse was defined as recurrence of CS syndrome requiring IS intensification: heart failure, ventricular arrhythmia, decrease in left ventricular ejection fraction, or increased disease burden on imaging. Among 68 patients, the mean age was 50.7±9.0years; 25 (37%) were women, and 32 (47%) were Black. In total, 59 patients (87%) reached remission. Over a median follow-up of 39.5months (interquartile range 17.6, 92.5), 28 (48%) relapsed. Greater percentage of late gadolinium enhancement (LGE) on pretreatment magnetic resonance imaging corresponded with increased likelihood of relapse (odds ratio 1.396 per 5% increase [95% confidence interval (CI) 1.04 to 1.88]; p=0.028). LGE ≥11% predicted elevated risk of relapse (adjusted odds ratio 4.998 [1.34 to 18.64]; p=0.017). Shorter time to relapse was observed with isolated CS (adjusted hazard ratio 4.084 [1.44,11.56]; p=0.008) and LGE ≥11% (adjusted hazard ratio 3.007 [1.01, 8.98]; p=0.049). Approximately 1 in 2 patients with CS in remission experienced relapse. Greater burden of LGE on cardiac magnetic resonance imaging and isolated CS are associated with greater risk of relapse. Future work is needed to refine risk stratification for relapse and to optimize surveillance strategies on the basis of the burden of disease.

Association between Left Atrial Late Gadolinium Enhancement and Atrial Fibrillation: The Multi-Ethnic Study of Atherosclerosis (MESA).

To determine the prevalence and correlates of left atrial (LA) late gadolinium enhancement (LGE) at cardiac MRI and its association with atrial fibrillation (AF) in a population-based sample from the Multi-Ethnic Study of Atherosclerosis (MESA). In this secondary post hoc analysis of the MESA cohort (ClinicalTrials.gov no. NCT00005487), participants without AF underwent LGE cardiac MRI at the fifth examination (2010-2012). LA LGE burden was quantified using the image intensity ratio technique on biplane long-axis two-dimensional (2D) LGE images without fat saturation. Survival analysis was performed with log-rank testing and Cox regression. Of 1697 participants (mean age, 67 years ± 9 [SD]; 872 men), 1035 (61%) had LA LGE, and 75 (4.4%) developed AF during follow-up (median, 3.95 years). At univariable analysis, LA LGE was associated with age (β = .010 [95% CI: .005, .015], P < .001), diastolic blood pressure (β = .005 [95% CI: .001, .009], P = .02), HbA1c level (β = .06 [95% CI: .02, .11], P = .009), heart failure (β = .60 [95% CI: .11, 1.08], P = .02), LA volume (β = .008 [95% CI: .004, .012], P < .001), and LA function (emptying fraction, LA global longitudinal strain, LA early diastolic peak longitudinal strain rate, and LA late diastolic peak strain rate; all P < .05). After adjusting for the variables in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) AF score, LA LGE independently helped predict incident AF (hazard ratio = 1.46 [95% CI: 1.13, 1.88], P = .003). The highest tertile (LGE > 2%) was twice as likely to develop AF. Although limited by the 2D LGE technique employed, LA LGE was associated with adverse atrial remodeling and helped predict AF in a multiethnic population-based sample.Clinical trial registration no. NCT00005487Keywords: MR Imaging, Cardiac, Epidemiology Supplemental material is available for this article. © RSNA, 2023.

A deep learning algorithm for noise reduction in a novel respiratory-triggered single-shot phase sensitive inversion recovery myocardial delayed enhancement cardiac MRI pulse sequence

Abstract Funding Acknowledgements Type of funding sources: None. Background Phase-sensitive inversion recovery improves tissue contrast by correcting for imperfect choice of inversion recovery time, however it is challenging to combine with a free-breathing acquisition. Deep learning (DL) algorithms have growing applications in cardiac MRI to improve image quality during image reconstruction. Purpose Here, we introduce a single-shot phase-sensitive myocardial delayed enhancement sequence with respiratory triggering (SShPSMDE-RT) (Figure 1). This novel sequence allows faster free-breathing acquisition of late gadolinium enhancement (LGE) images with reduced motion artifact (Figure 2.a). We combined this with a DL noise reduction algorithm to further improve image quality as compared to a standard segmented breath-hold (BH) PSMDE sequence. Methods 61 subjects (29 male, age 51±15) underwent cardiac MRI with the SShPSMDE-RT sequence and a standard BH sequence. The DL algorithm was applied at increasing levels (DL25, DL50, DL75, DL100) (Figure 2.b). Qualitative metrics were image quality, artifact severity, and diagnostic confidence, graded on a 5-point Likert scale. Quantitative metrics were sharpness of the left ventricle septum border and the LGE region (distance in mm for signal intensity to drop from 80% to 20%), blood-myocardium contrast-to-noise ratio (CNR), LGE-myocardium CNR, LGE signal-to-noise ratio (SNR), and LGE burden. 324 slices were included in the analysis. The sequences were compared via paired T-test. Results 27 subjects had positive LGE as determined by CMR experts. The average time to acquire a slice for SShPSMDE-RT is 4–7 seconds versus ∼30–40 seconds for the BH scan. The single-shot sequence had significantly better image quality (SShPSMDE-RT 2.1±0.8 vs. BH 1.5±0.6, p&amp;lt;0.001), less artifact (1.2±0.5 vs. 2.6±1.1, p&amp;lt;0.001), and better diagnostic confidence (3.4±0.7 vs. 2.6±0.8, p&amp;lt;0.001). Septum sharpness was slightly worse in SShPSMDE-RT images (4.1±1.7 mm vs. 3.8±1.6 mm, p = 0.008), but the DL algorithm improved sharpness of SShPSMDE-RT images such that there was no significant difference compared to BH images (p&amp;gt;0.5). There was no significant difference in LGE sharpness between the sequences. The SShPSMDE-RT images had superior blood-myocardium CNR (17.2±6.9 vs. 16.4±6.0, p = 0.040), LGE-myocardium CNR (12.1±7.2 vs. 10.4±6.6, p = 0.054), and LGE SNR (59.8±26.8 vs. 31.2±24.1, p&amp;lt;0.001); these metrics all improved with application of the DL algorithm. There was no significant difference in measured LGE burden (p = 0.12). Conclusions Our novel SShPSMDE-RT sequence significantly reduces scan time and motion artifact. This free-breathing sequence combined with a DL noise reduction algorithm provides better or similar image quality on both qualitative and quantitative metrics as compared to a standard BH PSMDE sequence. This technique can be used to obtain LGE imaging in patients who are unable to breath-hold or tolerate longer scan times.

Cardiac Magnetic Resonance Findings of Coronavirus Disease 2019 (COVID-19) Vaccine-Associated Myopericarditis at Intermediate Follow-Up: A Comparison with Classic Myocarditis

To report intermediate cardiac magnetic resonance (CMR) findings of coronavirus disease 2019 (COVID-19) vaccine-associated myopericarditis (C-VAM) and compare with classic myocarditis. Retrospective cohort study including children diagnosed with C-VAM from May 2021 through December 2021 with early and intermediate CMR. Patients with classic myocarditis from January 2015 through December 2021 and intermediate CMR were included for comparison. There were 8 patients with C-VAM and 20 with classic myocarditis. Among those with C-VAM, CMR performed at a median 3days (IQR 3, 7) revealed 2 of 8 patients with left ventricular ejection fraction <55%, 7 of 7 patients receiving contrast with late gadolinium enhancement (LGE), and 5 of 8 patients with elevated native T1 values. Borderline T2 values suggestive of myocardial edema were present in 6 of 8 patients. Follow-up CMRs performed at a median 107days (IQR 97, 177) showed normal ventricular systolic function, T1, and T2 values; 3 of 7 patients had LGE. At intermediate follow-up, patients with C-VAM had fewer myocardial segments with LGE than patients with classic myocarditis (4/119 vs 42/340, P=.004). Patients with C-VAM also had a lower frequency of LGE (42.9 vs 75.0%) and lower percentage of left ventricular ejection fraction <55% compared with classic myocarditis (0.0 vs 30.0%), although these differences were not statistically significant. Five patients with classic myocarditis did not receive an early CMR, leading to some selection bias in study design. Patients with C-VAM had no evidence of active inflammation or ventricular dysfunction on intermediate CMR, although a minority had persistent LGE. Intermediate findings in C-VAM revealed less LGE burden compared with classic myocarditis.

Late-gadolinium enhancement is common in older pediatric heart transplant recipients and is associated with lower ejection fraction

BackgroundChronic graft failure and cumulative rejection history in pediatric heart transplant recipients (PHTR) are associated with myocardial fibrosis on endomyocardial biopsy (EMB). Cardiovascular magnetic resonance imaging (CMR) is a validated, non-invasive method to detect myocardial fibrosis via the presence of late gadolinium enhancement (LGE). In adult heart transplant recipients, LGE is associated with increased risk of future adverse clinical events including hospitalization and death. We describe the prevalence, pattern, and extent of LGE on CMR in a cohort of PHTR and its associations with recipient and graft characteristics.MethodsThis was a retrospective study of consecutive PHTR who underwent CMR over a 6-year period at a single center. Two independent reviewers assessed the presence and distribution of left ventricular (LV) LGE using the American Heart Association (AHA) 17-segment model. LGE quantification was performed on studies with visible fibrosis (LGE+). Patient demographics, clinical history, and CMR-derived volumetry and ejection fractions were obtained.ResultsEighty-one CMR studies were performed on 59 unique PHTR. Mean age at CMR was 14.8 ± 6.2 years; mean time since transplant was 7.3 ± 5.0 years. The CMR indication was routine surveillance (without a clinical concern based on laboratory parameters, echocardiography, or cardiac catheterization) in 63% (51/81) of studies. LGE was present in 36% (29/81) of PHTR. In these LGE + studies, patterns included inferoseptal in 76% of LGE + studies (22/29), lateral wall in 41% (12/29), and diffuse, involving > 4 AHA segments, in 21% (6/29). The mean LV LGE burden as a percentage of myocardial mass was 18.0 ± 9.0%. When reviewing only the initial CMR per PHTR (n = 59), LGE + patients were older (16.7 ± 2.9 vs. 12.8 ± 4.6 years, p = 0.001), with greater time since transplant (8.3 ± 5.4 vs. 5.7 ± 3.9 years, p = 0.041). These patients demonstrated higher LV end-systolic volume index (LVESVI) (34.7 ± 11.7 vs. 28.7 ± 6.1 ml/m2, p = 0.011) and decreased LV ejection fraction (LVEF) (56.2 ± 8.1 vs. 60.6 ± 5.3%, p = 0.015). There were no significant differences in history of moderate/severe rejection (p = 0.196) or cardiac allograft vasculopathy (CAV) (p = 0.709).ConclusionsLV LGE was present in approximately one third of PHTR, more commonly in older patients with longer time since transplantation. Grafts with LGE have lower LVEF. CMR-derived LGE may aid in surveillance of chronic graft failure in PHTR.

299 LEFT VENTRICULAR APICAL THROMBUS

Abstract LV thrombus is a complication of AMI. It is estimated that 40-60% of patients with large anterior wall MI will develop a LV thrombus. The risk is highest during the first 3 months following AMI. Accurate and timely detection is important as it poses a high risk for thromboembolic events. Advances in technology have improved the detection rate of intracardiac thrombi, but several uncertainties still remain regarding the optimal treatment strategy within daily clinical practice. We report a case of large LV thrombus in a 61-year-old male with extensive anterior wall MI. A 61-year-old man, hypertension, former smoker, subjected to epatic orthotopic transplant for HCC and treated with immunosuppressive therapy (Everolimus), following development of lymphocytic leukemia in fu. He underwent thoracic ct, wich showed a hypodense imaging in the left ventricular apex referable to thrombotic formation large 2cm, with endocardial rim hypointense like ischemic outcomes. The ECG demonstrated Q waves in anterior leads and biphasic T waves in the same leads. The patient was absolutely asyntomatic. A transthoracic echocardiography, showed the apical mass (2×0,9cm) very mobile and akinesia and thinning of the left ventricol middle-apical wall with apical aneurysmatic evolution. A CMR, confirmed the presence of the thrombus and showed defects at the subendocardial layer of the anterior wall and interventricular septal with also involvement of all the apex; the burden of late gadolinium enhancement (ischemic pattern) extended to the same segment. Coronary angiography showed subocclusion involving the second tract of the left anterior descending (99%) and critical coronary stenosis of the third tract of the right coronary (70%). The thrombus was completely removed surgically through left atriotomy, in prevention of embolization due to the thrombus dimension, the motility and the labile docking station. The histological examination confirmed the thrombotic nature of the mass. International guidelines agree on recommending anticoagulation therapy for patients affected by left ventricular thrombosis. OAC with vitamin K antagonists should be started as soon as LVT is identified, as first-line therapy and parenteral anticoagulation should be discontinued when effective therapeutic range with warfarin has been achieved (INR of 2–3). European and American guidelines stressing the efficacy of parenteral therapy with heparin; there are no randomized trials that have examined the efficacy of VKA anticoagulation compared with parenteral therapy. DOACs are attractive alternatives because of their potential efficacy and safety even though there is no trial that proves the effect of DOACs in LVT. Oral anticoagulation should be discontinued as soon as thrombus resolution has been established. Surgical removal of the LVT is an option for patients with high embolic risk, as in our patient. The high morbidity and mortality of this approach outweigh the benefits of performing surgery solely for the indication of LVT.

Septal myocardial scar burden predicts the response to cardiac contractility modulation in patients with heart failure

We hypothesized that myocardial septal scarring, assessed by cardiac magnetic resonance (CMR) using late gadolinium enhancement (LGE), at the site of cardiac contractility modulation (CCM) lead placement may predict treatment response. Eligible heart failure (HF) patients underwent LGE CMR imaging before CCM device implantation. The response to CCM therapy at follow-up was determined by a change in NYHA class and echocardiographic left ventricular ejection fraction (LVEF) assessment. Patients were classified as responders, if they showed an improvement in either NYHA class or improvement of LVEF by ≥ 5%. 58 patients were included. 67% of patients were classified as responders according to improved NYHA; 55% according to LVEF improvement. 74% of patients were responders if either NYHA class or LVEF improvement was observed. 90% of responders (according to NYHA class) showed septal LGE < 25% at septal position of the leads, while 44% of non-responders showed septal LGE > 25% (p < 0.01). In patients treated with CCM, an improvement of NYHA class was observed when leads were placed at myocardial segments with a CMR- LGE burden less than 25%.

Abstract 9395: Natural History of Myocardial Injury Following Covid-19 Vaccine Associated Myocarditis

Introduction: Acute myocarditis is a rare complication of mRNA-based COVID-19 vaccination. The natural history and clinical sequalae of this complication are of critical importance to estimate the impact on population health. Objective: To study the impact of COVID-19 vaccine associated myocarditis on convalescent myocardial health, symptoms, and clinical outcomes. Methods: This study was performed at two tertiary care hospitals. Baseline and convalescent (≥3 month) CMR imaging was performed for 20 consecutive patients meeting Updated Lake Louise Criteria for acute myocarditis within 10 days of mRNA-based vaccination and with no evidence of active viral infection. Global and segmental CMR-based markers of myocardial injury were studied at baseline and convalescence, inclusive of chamber volumetry, LV ejection fraction (LVEF), LV mass, T1 and T2 mapping, late gadolinium enhancement (LGE) imaging, and extracellular volume (ECV) fraction. Major clinical outcomes were captured. Results: The median age was 23.1 years (range 18-39 years) with 17 (85%) being male. Convalescent CMR evaluations were performed at a median (IQR) of 3.7 (3.3-6.2) months. Five patients (25%) had a baseline LVEF &lt;50%. All patients showed abnormal LGE inclusive of a sub-epicardial pattern with a mean LGE burden of 8.6+/-5.3% LV mass using a &gt;5SD of reference threshold. At follow-up, a mean 3% absolute improvement in LVEF was observed, accompanied by a 7% reduction in LVEDV and 5% reduction in LV mass (all p&lt;0.015). Global LGE volume reduced by 66% (p&lt;0.001). Absolute reductions in global T2, native T1, and ECV of 2.1msec, 58msec, and 2.9%, respectively were documented (all p≤0.001). All patients with LVEF &lt;50% at baseline recovered above this threshold. However, 18 (90%) patients showed persistence of LGE at follow-up with 15% having a burden &gt;5% of the LV mass. No patient experienced major clinical outcomes. Conclusion: COVID-19 mRNA vaccine associated myocarditis shows rapid improvement in CMR-based markers of tissue edema, contractile function, and LGE, and was not associated with adverse events at intermediate range follow-up. However, convalescent fibrosis was commonly observed, justifying ongoing need for clinical surveillance in this population.

Microvascular dysfunction is associated with impaired myocardial work in obstructive and nonobstructive hypertrophic cardiomyopathy: a multimodality approach

Abstract Introduction Myocardial work is a dynamic non-invasive method for assessing myocardial deformation. Microvascular dysfunction is a hallmark of hypertrophic cardiomyopathy (HCM). We hypothesized that there is an association between impaired myocardial work, evaluated by echocardiography, and left ventricular (LV) ischemia, detected by cardiac magnetic resonance (CMR). Methods Prospective assessment of HCM patients' (P) myocardial strain parameters with 2D speckle-tracking echocardiography. All P underwent CMR protocol (1.5-T) for the analysis of stress perfusion and late gadolinium enhancement (LGE). Perfusion defects were quantified as burden of ischemia (% of LV mass). Results were stratified according to obstructive (oHCM) and nonobstructive (nHCM) HCM as well as according to the presence of significant replacement fibrosis (LGE of ≥15% or &amp;lt;15% of LV mass). Multivariate regression analyses were used to explore the relation between myocardial work and the burden of ischemia. Results 75 P with HCM (63% male, age 55±15 years), 61% with asymmetric septal LVH, 29% with apical LVH, 8% with concentric LVH and 28% exhibiting LV outflow tract obstruction (mean maximal LVOT gradient of 89±60 mmHg). Perfusion defects were found in 68 P (90.7%), with a mean of 22.5±16.9% of LV mass and 29 P (38.7%) had LGE ≥15% of LV mass. A lower global work index (GWI) significantly correlated with higher burden of myocardial perfusion defects (r=−0.520, β-estimate −0.019, 95% CI −0.028 to −0.010, p&amp;lt;0.001). Likewise, impaired values of global work efficiency (GWE) were linked to higher percentage of hypoperfusion (r=−0.477, β-estimate −0.713, 95% CI −1.250 to −0.176, p&amp;lt;0.001). Moreover, impaired global constructive work (GCW) (r=−0.519, β-estimate −0.021, 95% CI −0.030 to −0.013, p&amp;lt;0.001) and a higher global wasted work (GWW) (r=0.280, p=0.017) were associated with a higher burden of perfusion defects (Figure 1). GWI showed a higher correlation with perfusion defects in oHCM P (r=−0.518, p=0.019) vs. nHCM P (r=−0.492, p&amp;lt;0.001), and the same was also found with GWE (oHCM: r=−0.591, p=0.006 vs. nHCM: r=−0.317, p=0.022) (Figure 2A). Furthermore, GCW showed a slightly higher correlation with hypoperfusion in oHCM P (r=−0.564, p=0.010) vs. nHCM P (r=−0.520, p&amp;lt;0.001). There was no significant difference between oHCM and nHCM P regarding GWW. In P with LGE ≥15%, GWI showed a better correlation with perfusion defects (r=−0.489, p=0.007) vs. P with LGE of &amp;lt;15% (r=−0.369, p=0.007). Moreover, GCW showed a higher correlation with hypoperfusion in P with LGE ≥15% (r=−0.455, p=0.013) comparing with P with LGE &amp;lt;15% LV mass (r=−0.359, p=0.019) (Figure 2B). No difference was found regarding GWE and GWW according to LGE burden. Conclusion In our cohort of P with HCM, impaired GWI, GWE and GCW and a higher GWW were significantly correlated with the presence of myocardial ischemia in CMR. This correlation was greater in P with oHCM and in P with LGE of ≥15% of LV mass. Funding Acknowledgement Type of funding sources: None.

TIMI flow and myocardial blushing after rescue PCI and cardiac magnetic resonance: Results from the Myocardial Salvage After Rescue Angioplasty: Evaluation by Magnetic Resonance (SAVE-ME) study

Thrombolysis is currently reserved for ST-elevation myocardial infarction (STEMI) patients who cannot access timely percutaneous coronary intervention (PCI). In case of failed thrombolysis, rescue PCI is a viable option. Substantial data concerning the outcomes in terms of infarct size and myocardial function after rescue PCI are lacking. Forty patients treated with rescue PCI underwent serial contrast-enhanced cardiac magnetic resonance imaging (CMR) at 1week, 3months and 6months from the index STEMI. Angiographic images were reviewed to assess Thrombolysis in Myocardial Infarction (TIMI) blood flow and TIMI Myocardial Blush Grade (TMBG) in the infarct related artery after PCI. Patients with lower TMBG at the end of procedure, but not patients with worse TIMI flow, had lower left ventricular ejection fraction (LVEF) and higher volume of late gadolinium enhancement (LGE) on baseline CMR (44±13% vs 52±9%, p=0.026, and 41±21ml vs 26±12, p=0.030, respectively). Patients with lower TMBG remained with significantly lower LVEF at 6months follow up (48±16% vs 59±14, p=0.049). TMBG after rescue PCI is associated with reduced LVEF and increased LGE burden. As TMBG is a known marker of microvascular damage after STEMI, novel strategies aimed at improving microvascular function in the setting of rescue PCI are needed to improve the outcomes in this patient population.

Characteristics of COVID-19 Myocarditis With and Without Multisystem Inflammatory Syndrome

Multisystem inflammatory syndrome (MIS) is a severe complication described in a minority of patients with COVID-19. Myocarditis has been reported in patients with COVID-19, including MIS. In this study, we compared the clinical characteristics and cardiac magnetic resonance (CMR) findings of COVID-19 myocarditis in patients with and without MIS. In the 330 patients with COVID-19 who were referred for CMR at our institution between July 24, 2020, to March 31, 2021, 40 patients were identified as having myocarditis, MIS myocarditis (n = 21) and non-MIS myocarditis (n = 19). MIS myocarditis was characterized by global myocardial inflammation/edema with significantly elevated native T1, whereas only regional inflammation, and edema were noted in the non-MIS group. Distinct late gadolinium enhancement (LGE) patterns—inferior myocardial involvement in non-MIS myocarditis and septal involvement in MIS myocarditis—were identified. The LGE burden was comparable between the 2 groups (5.9% vs 6.6%, MIS vs non-MIS group, p = 0.83). Myocarditis was diagnosed more frequently by CMR in the MIS group (70% vs 6.3%, MIS vs non-MIS, p <0.001). In the 20 patients with a sequential CMR study at a median 102-day follow-up, 25% had persistent myocardial edema. The LGE burden improved over time, from a median of 5.0% (interquartile range 3.4% to 7.3%) to 3.2% (interquartile range 2.0% to 3.8%; p <0.001). In conclusion, MIS and non-MIS myocarditis exhibit distinct characteristics by CMR. Persistent LGE and edema were common at follow-up CMR examination in both groups.

B-PO05-118 RIGHT VENTRICULAR LONGITUDINAL STRAIN ON CMR PREDICTS VENTRICULAR ARRHYTHMIC AND MORTALITY IN CARDIAC SARCOIDOSIS

Ventricular arrhythmias (VA) are a leading cause of death in patients with cardiac sarcoidosis (CS). Right ventricular (RV) dysfunction and late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR) have been linked to incidence of VAs. However, detection of LGE of the RV is limited by image resolution. Global longitudinal RV strain (RVS) correlates to RV scar on electroanatomical mapping, and is a valid measure of regional RV function. We evaluated the association between RVS on CMR and incidence of VAs, cardiovascular (CV) death, and heart transplantation (HT) (combined primary end-point) in patients with CS. In this retrospective study, 71 patients with probable or definite CS were included. RVS and RV LGE on MRI were compared to variables known to predict arrhythmic and mortality outcomes in CS. Outcomes were obtained by review of electronic medical records and cardiac implantable electronic device interrogations over a median [IQR] follow-up period of 3.7[1.7, 6.3) years. Cox proportional hazard models were used to evaluate the probability of event-free survival. Harrell’s C statistic was used to compare variables in risk prediction models. 59% of patients were male, with median age [IQR] of 52.3 [42.4, 62.2] years, and left ventricular ejection fraction (LVEF) of 54.9%[41.4, 68.4]. During the follow-up period, 13 patients developed the primary endpoint and were more likely to have a history of Vas (HR[95% CI] 6.80[1.86,24.8],p=0.004) and higher LV LGE burden (1.07[1.01,1.12], p=0.02). In a multivariate analysis adjusted for age, race, and history of VA, decreased RVS was a significant predictor of the primary outcome (0.84[0.71, 0.98], p=0.03), whereas RV LGE, RV end-diastolic volume (EDV) and RV EF were not. Risk prediction models including RVS (Harrell’s C statistic 0.87) were superior to those including only RV LGE (0.79) or LV LGE burden (0.82). Global RVS on CMR was the best predictor of VAs or CV death in patients with CS.

Prognostic assessment following acute myocarditis requires convalescent scanning: neither peak troponin nor index scan T2 signal predicts convalescent late gadolinium enhancement

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiovascular magnetic resonance (CMR) is a key diagnostic investigation in acute myocarditis (1) and permits quantification of late gadolinium enhancement (LGE) and myocardial oedema. Follow-up CMR imaging is recommended to check for persistence of scar and oedema (2). Persistent late gadolinium enhancement is associated with a worse prognosis (3). It is not known whether all patients require follow-up scanning or whether the initial scan can provide useful information to identify which patients need convalescent assessment. Purpose In this study we considered whether extent of troponin elevation, extent of T2 elevation and initial late gadolinium enhancement burden predicted long-term late gadolinium enhancement at follow-up. Methods Index and follow-up CMR scans of consecutive patients presenting with a diagnosis of acute myocarditis between 2019 and 2020 across three hospitals were included. Inclusion criteria were: follow-up scan within 9 months of the index scan, CMR with LGE imaging and T2 mapping, and acute myocarditis being the primary diagnosis of the index scan. Myocardial T2 values in the area affected by myocarditis and percentage of LV myocardium showing late enhancement (using a threshold-based full height half width or manual region of interest strategy) were extracted. Results 20 patients were included in the study (80% male; mean age 37 years). Mean interval between the index and follow-up scan was 4.1 months. Peak troponin level during the acute illness was not associated with the proportion of LV myocardium affected by LGE in the index scan (R^2 &amp;lt;0.01) (Figure 1A). Myocardial T2 values in the first scan were not associated with the proportional resolution in LGE between the index and follow-up scans (R^2 0.02) (Figure 1B). The mean change in LGE was -61.7% (+/-22.8%) but the initial LGE burden did not predict the proportional degree of improvement in LGE between scans (R^2 &amp;lt;0.01)(Figure 1C). Conclusions The extent of troponin elevation and initial CMR phenotype was not a good predictor of the burden of long-term late gadolinium enhancement. Although most cases showed improvement in LGE scar burden between index and follow-up imaging, neither peak troponin level during the acute episode, nor T2 values at the first CMR scan were predictive of initial or change in scar burden. Serial CMR assessment is required to identify those patients who have residual long-term scarring.

Ring-like late gadolinium enhancement for predicting ventricular tachyarrhythmias in non-ischaemic dilated cardiomyopathy.

Myocardial fibrosis is associated with clinical ventricular tachyarrhythmia (VTA) events in patients with non-ischaemic dilated cardiomyopathy (DCM). Subepicardial or mid-wall ring-like late gadolinium enhancement (LGE) has received increasing attention in recent years. The aim of this study was to investigate the relationship between ring-like LGE and VTAs in DCM. Patients diagnosed with non-ischaemic DCM who underwent cardiac magnetic resonance with LGE imaging at baseline were investigated. The composite outcome was the occurrence of VTAs defined as sustained ventricular tachycardia, ventricular fibrillation/flutter, aborted sudden cardiac death (SCD), SCD, and appropriate implantable cardioverter-defibrillator intervention. The final cohort comprised 157 patients, including 36 (22.9%) in no LGE group, 48 (30.6%) in focal LGE group, 40 (25.5%) in multi-focal LGE group, and 33 (21%) in ring-like LGE group. Ring-like LGE group patients were younger compared to focal and multi-focal LGE group (P < 0.001) with higher left ventricular ejection fraction (33.0% vs. 24.4% vs. 22.1%, P < 0.001). After a median of 13 ± 7 months follow-up, compared to patients with no LGE, the hazard ratios (HRs) with 95% confidence intervals (CIs) for VTAs were 2.90 (0.56-15.06), 5.55 (1.21-25.44), and 11.75 (2.66-51.92) for patients with focal LGE, multi-focal LGE, and ring-like LGE, respectively. After multivariable adjustment, ring-like LGE group remained associated with increased risk of VTAs (adjusted HR 10.00, 95% CI 1.54-64.98; P = 0.016) independent of the global LGE burden. The ring-like pattern of LGE is independently associated with an increased risk of VTAs in patients with non-ischaemic DCM.