Magnetic Resonance Imaging Research Articles

Novel computational approach enables tailoring catheter ablation to a patient and evaluating the role of reverse remodelling in atrial fibrillation recurrence

Abstract Background Atrial Fibrillation (AF) is the most common cardiac arrhythmia affecting up to 2.5% of the population, decreasing the quality of life and increasing the chances of stroke five-fold. Radiofrequency Catheter Ablation (RFCA) is an emerging technique that warrants long-term curative treatment of AF. However, its success rate remains sub-optimal, with 50% of the arrhythmias recurring at 1-year follow-up. AF is a self-sustained condition that perpetuates by altering the atrial structure and cellular electrophysiological properties, the process referred to as remodelling. However, these changes can be reversible after successful AF treatment. Aim This study aims to create a novel, patient-tailored RFCA technique that targets re-entrant activity in the left atrium (LA), to test the technique in-silico, and to investigate the importance of reverse remodelling in AF recurrence after RFCA. Methods LA meshes with fibrosis were segmented from Late Gadolinium Enhanced Magnetic Resonance (LGE MR) images of AF patients (n = 13) and combined with the Courtemanche-Ramirez-Nattel (CRN) atrial electrophysiology model to create patient-specific 3D LA models. AF was initiated through the pacing at the end of effective refractory period (PEERP) protocol. The first ablation was automated to target the cores of re-entrant drivers. If this led to AF termination, recurrence was tested by pacing in the same 3D LA models with two variants of CRN electrophysiology: (i) AF-remodelled model, and (ii) healthy, i.e. reverse-remodelled model. If recurrence was present in either case, the second ‘redo’ ablation was performed using the same technique targeting the new re-entrant drivers. AF recurrence was then tested again (Figure). Results The first ablation terminated AF in all 13 patient-specific models. In the following PEERP test, AF recurrence rate was (i) 51.92% in the AF-remodelled cases (out of which, 37.04% of new drivers originating in the anterior wall, and 62.96% in the posterior wall). AF recurrence rate was only (ii) 5.77% in the reverse remodelled cases (all drivers originating in the posterior wall). The second ‘redo’ ablation was performed for all recurrent cases and terminated AF with 92.31% success rate. The second procedure also increased the freedom from AF after the PEERP test: (i) 37.5% recurrence for the remodelled cases (44.44% anterior, 55.56% posterior) and (ii) no recurrence in the reverse-remodelled cases. Conclusion This study shows the importance of reverse remodelling in the success of RFCA treatment for AF. In-silico ablation of patient-specific 3D LA models shows that AF recurrence drops to 5.77% and 0% after the first and second procedure, respectively, if the LA is reverse-remodelled. Our novel approach can be used to help improve clinical RFCA therapy.Computational pipeline for AF Treatment

Intramyocardial fatty infiltration lesion in sporadic inclusion body myositis: a case report.

Sporadic inclusion body myositis (sIBM), the most common inflammatory muscle disorder in adults over 50 years, is often misdiagnosed due to its gradual onset and its common but unspecific muscle weakness in older adults. Diagnosis relies on clinical, radiological, and pathological features. Cardiac involvement is rare, prompting this case description and a comprehensive literature analysis. A 73-year-old woman diagnosed with sIBM in 2021 through muscle biopsy had been experiencing muscular symptoms since 2015. Her condition progressively worsened, affecting daily activities. Annual follow-ups revealed a moderate obstructive syndrome on respiratory testing, prompting a cardiac evaluation. Cardiac magnetic resonance (CMR) imaging identified intramyocardial lesions consistent with fatty infiltration, highlighting the interest of advanced imaging in sIBM management. Cardiac involvement in sIBM is presumed rare compared to other idiopathic inflammatory myopathies, though the exact frequency remains unclear. Early identification of heart alterations by CMR in sIBM can be prognostically valuable, guiding follow-up and interventions. However, literature on this subject is limited to small cohort studies and case reports describing complications. Given the slow progression of sIBM and the limited efficacy of current treatments, the discovery of myocardial lesions could warrant closer cardiological monitoring. Larger cohort studies are needed to explore potential new therapeutic approaches. Our case underscores the importance of CMR in detecting subtle cardiac manifestations in sIBM and illustrates the potential prognostic value of cardiac assessment in the management of sIBM.

Improving prognostic accuracy in ischemic cardiomyopathy: the CMR-LGE score

Abstract Background There is a need for accurate prognostic stratification tools in patients with ischemic cardiomyopathy (ICM). Several studies have shown the considerable impact of cardiac magnetic resonance (CMR) imaging findings notably late gadolinium enhancement (LGE) but an easy interpretable score to guide clinical practice is lacking. Purpose To determine the CMR parameters most predictive of mortality in a cohort of ICM patients with left ventricular ejection fraction (LVEF) less than 50%, and then to develop a readily interpretable score based on these parameters. Methods Between 2008 and 2022, all consecutive patients with a history of ICM with LVEF<50% and presence of ischemic LGE on viability CMR examination, were recruited by two independent centers. The primary outcome was all-cause death using French National Registry of Death. The first center (N=2,900) was designated as the derivation cohort for variable selection and score development, and the second center (N=691) was used as the validation cohort to evaluate the performance of the final score. Thirty-two variables (17 clinical and 15 CMR) were initially assessed. Automatic feature selection was performed using a machine-learning approach with a Random Survival Forest (RSF) algorithm. Using the selected variables, our proposed score, the CMR-LGE score, was derived from coefficients of the Cox regression. Performance evaluation on the validation cohort was conducted using Harrel’s C index compared with traditional prognostic factors associated with poor outcomes in ICM. Categories for the prognostic score were identified using a survival conditional inference tree analysis on the derivation cohort, aiming to maximize the log-rank score. Results Among the 3,591 patients included (mean age 65±12 years; 75% male; mean LVEF 44±6%), 549 (15.3%) died over a median follow-up of 9 (interquartile range: 7–12) years. Feature selection with RSF highlighted that the most important variables to predict death were LGE variables: the extent, the location (septal and anterior) and the transmurality of ischemic LGE as well as the extent of additional midwall LGE (Figure 1). Following these findings, we developed the CMR-LGE score by rounding the coefficient of a Cox regression (Figure 2A). Harrel’s C index of CMR-LGE score outperformed traditional prognostic factors, including LVEF (0.88 vs 0.69). Finally, based on our CMR-LGE score, we identified a low-risk population (CMR-LGE score below 6) and a high-risk population (CMR-LGE above 8), validated using survival curves in the validation cohort (Figure 2B). Conclusion Using RSF, we identified that the 5 most important CMR variables to predict mortality in ICM were all LGE features. Our CMR-LGE score showed excellent performance to stratify patient risk compared to traditional prognostic factors including LVEF.Variable selectionModel building and evaluation

The effect of Trimetazidine on the left ventricular global longitudinal strain assessed by cardiac magnetic resonance in stable angina patients with previous myocardial infarction and left ventricular

Abstract Introduction Trimetazidine (TMZ) is an anti-ischemic metabolic agent that is indicated in adults as add-on therapy for the symptomatic treatment of patients with stable angina pectoris (SA). Global left ventricular (LV) systolic function is an important predictor of outcomes in patients after myocardial infarction (MI). Cardiac magnetic resonance (CMR) imaging has now evolved into a major tool for the evaluation of patients with LV dysfunction, providing precise measurements of ejection fraction (EF) and viability assessment but also now allowing assessment of global longitudinal strain (GLS) from standard cine CMR images. We hypothesized that the use of TMZ 80 mg as an anti-ischemic agent in patients with SA, history of MI, reduced EF and in the presence of viable myocardium may produce an early modification of GLS. Methods TRIM-AZ - was a non-interventional, prospective Azerbaijan study to analyze the capacity of short-term therapy with TMZ 80 mg on LV GLS evaluated by CMR in patients with previous MI. Patients with a confirmed diagnosis of heart failure (HF) with impaired LV systolic function and SA in the presence of viable myocardium were included. The treatment of all patients was optimized according to the latest ESC guidelines before entry in the study. Patients were randomized into two groups, one received TMZ 80 mg on top of guidelines directed medical therapies, and the other was the control group. A CMR as well as a transthoracic echography were performed for all patients at the inclusion visit and 8 weeks later. Results 52 patients were included in the study, 30 patients in the TMZ group and 22 in the control group,. At baseline, the mean age was 62±7 years , 63% were smokers, 60% hypertensive, 60% diabetics, 48% had a family history of MI, 12% had typical symptoms of SA while 88% had atypical form (e.g. like shortness of breath). All patients received baseline therapy with ARNI/ACE-i, SGLT2 inhibitors, beta-blockers, MRA, ASA, and statin. 8 weeks after the initiation of TMZ, there were no significant changes in LVEF assessed both by Echo and CMR (29,8%±3,2% vs 30,1%±3,5% by echo in TMZ group; 31,3%±2,7% vs 31,6%±2,7% by echo in the control group; 25,9%±3,1% vs 26,9±4,1% by CMR in TMZ group; 26,9%±2,1% vs 30,1%±2,3% by CMR in the control group), however GLS was significantly improved in TMZ group (-9,9%±1,1% to -12,7%±1,2%, p=0,00), but not in control group (-9,3%±1,3% vs -10,3%±1,4% p=0,3). No adverse event related to TMZ use was reported during the study. Conclusion These findings suggest that the use of trimetazidine in patients with stable angina , previous MI and heart failure in the presence of viable myocardium could improve the left ventricular global longitudinal strain assessed by CMR.

DPD quantification correlates with ECV and disease severity in patients with ATTR-CM

Abstract Background The pathophysiological hallmark of transthyretin amyloid cardiomyopathy (ATTR-CM) is the deposition of amyloid within the myocardium. However, the association between myocardial amyloid load and quantitative cardiac 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) uptake is barely investigated. Purpose We aimed to investigate the relationship between quantitative cardiac 99mTc-DPD uptake and myocardial amyloid load, assessed by extracellular volume (ECV) on cardiac magnetic resonance (CMR) imaging, along with cardiac function in patients with ATTR-CM. Methods Forty ATTR-CM patients underwent 99mTc-DPD single-photon emission computed tomography/computed tomography (SPECT/CT) and CMR imaging. Results We observed significant correlations (r, Spearman's correlation coefficient) between the standardized uptake value (SUV) retention index and myocardial amyloid load (ECV: r=0.677, p<0.001; native T1 time: r=0.430, p=0.006), longitudinal cardiac function [right ventricular longitudinal strain (RV-LS): r=0.472, p=0.002], cardiac biomarkers (NT-proBNP: r=0.543, p<0.001; troponin T: r=0.401, p=0.011), exercise capacity [6-min walking distance (6MWD): r=-0.410, p=0.010] and disease stage [National Amyloidosis Centre (NAC) ATTR stage: r=0.479, p=0.002]. ATTR-CM patients were divided into two cohorts based on the median of the SUV retention index (low cardiac uptake: <5.19 mg/dL, n=20; high cardiac uptake: ≥5.19 mg/dL, n=20). We observed significant between-cohort differences in terms of ECV (p<0.001), native T1 time (p=0.011), RV-LS (p=0.007), NT-proBNP (p<0.001), troponin T (p=0.030), 6MWD (p=0.002) and NAC ATTR stage (I: p<0.001, II: p=0.030, III: p=0.021). Conclusions In ATTR-CM, quantitative cardiac 99mTc-DPD uptake correlates with myocardial amyloid load, longitudinal cardiac function, cardiac biomarkers, exercise capacity, and disease stage. DPD quantification may provide a valuable tool for quantifying and monitoring cardiac disease burden in affected individuals.Table.Baseline Characteristics.Figure.Correlations.

Pericardial adhesion and performance of hemodynamically significant constrictive pericarditis using cine magnetic resonance feature tracking.

To investigate the diagnostic performance of cine magnetic resonance feature tracking (FT) for pericardial adhesions and hemodynamically significant constrictive pericarditis (CP). This retrospective study included patients who underwent cardiac magnetic resonance (CMR) imaging between 2011 and 2021. Twenty-four patients (median age, 73 years; seven females) suspected of having CP and undergoing CMR were selected (CP group). Age-matched 24 participants with heart failure (HF) and 24 healthy volunteers were also analyzed. The FT method assessed septal bounce, the presence of a dip or plateau pattern, and pericardial adhesions. The diagnostic performance, including the area under the receiver operating characteristic curve (AUC) for hemodynamically significant CP, was evaluated against catheterization results, and the adhesion detection in the combined CP and HF control was based on cine tagging or surgical records. Septal bounce was detected in 54% (13/24) of the patients by FT and 38% (9/24) of the patients by visual evaluation in the CP group but not in the HF or normal group (p < 0.001). To detect hemodynamically significant CP, the sensitivity and specificity of each finding were as follows: septal bounce, 85% (11/13) and 82% (9/11); adhesion, 100% (13/13) and 9% (1/11); dip, 77% (10/13) and 36% (4/11); and plateau, 69% (9/13) and 46% (5/11), respectively. The sensitivity and specificity of pericardial adhesion detection using FT and visual evaluation were 96% (23/24) and 100% (24/24), respectively, and the AUCs were 0.998 and 0.999, respectively. CMR-FT demonstrates high sensitivity and specificity for diagnosing hemodynamically significant CP and pericardial adhesions.

Type 2 diabetes individuals have a shorter QRS duration, prolonged QTc interval, flatter T wave, and reduced left ventricular cycle volumes compared to matched controls in the UK Biobank

Abstract Background Type 2 diabetes is associated with an increased risk of heart failure even in the absence of overt coronary artery disease, though underlying mechanisms are unclear. ECG and cardiac magnetic resonance (CMR) imaging provide windows into subclinical changes in myocardial structure and function and could be exploited to understand this. Purpose We investigate differences in ECG and CMR biomarkers in a large cohort of participants with type 2 diabetes, compared to a matched control cohort. We hypothesise that individuals with diabetes may exhibit concurrent differences in biomarkers, reflecting underlying cardiac remodelling. Methods We carried out a pair-matched cross-sectional study to examine the association between type 2 diabetes and multi-modal cardiac biomarkers. The exposure cohort consists of 1,781 UK Biobank participants with an imaging and ECG visit, prevalent type 2 diabetes and no known cardiovascular events at the time of visit. The control cohort is matched on age, sex and body mass index (BMI), and consists of 1,781 participants without diabetes. ECG and CMR biomarkers derived from UK Biobank data were used as outcome variables. We built four multiple multivariate linear regression models, incrementally adjusted for socio-demographic, lifestyle, and clinical covariates. Results Both cohorts were mostly male (63.6%), had a median age of 67 years [IQR: 72-85] and a median BMI of 27.8 kg/m2 [24.6-31.0]. Individuals with type 2 diabetes were more likely to be non-white (7.9% vs 2.7%, p&amp;lt;0.001), current or previous smokers (43.6% vs 40.6%, p=0.04), have lower diastolic blood pressure (79 [72-85] vs 81 [74-88] mmHg, p&amp;lt;0.001), and take cholesterol medication (72.3% vs 27.2%, p&amp;lt;0.001); anti-hypertensives (56.3% vs 27.3%, p&amp;lt;0.001); insulin (13.7% vs 0.1%, p&amp;lt;0.001); and metformin (53.1% vs 0.1%, p&amp;lt;0.001). They had a higher ventricular rate, shorter QRS duration, longer QTc interval, and flatter T wave amplitude, as well as lower left ventricular end-diastolic and end-systolic volumes, among other differences (Table 1). Covariates including cholesterol medication, metformin, and HbA1c were excluded as they were strongly correlated with diabetes, age and/or sex (Pearson correlation coefficient &amp;gt;0.3 or &amp;lt;-0.3). After full adjustment, we found that the exposure variable, diabetes, had a statistically significant association with ventricular rate, QRS duration, T wave offset, T wave amplitude in lead V3, left ventricular stroke volume and global average thickness (p&amp;lt;0.05) (Table 2). Conclusion Our results reveal that individuals with type 2 diabetes exhibit a shorter QRS, longer QTc, and lower end-diastolic and end-systolic volumes, compared to matched controls. This may be indicative of subclinical cardiac abnormalities, both electrophysiological and mechanical. Our association analysis suggests that other factors correlated with diabetes may be also responsible for certain biomarker differences and their underlying causes.

Genome-wide association study of CMR image-based aortic stiffness in 45,789 individuals identifies loci linked with cardiovascular diseases

Abstract Background The use of artificial intelligence on large-scale cardiac magnetic resonance (CMR) imaging data has enabled detailed characterisation of cardiac shape and function for use in genome-wide association studies (GWAS), leading to improved understanding of genetic aetiology of cardiovascular diseases (CVDs). Aortic stiffness is associated with increased risk of cardiovascular events in observational studies. Here, we present a novel CMR-based pressure-independent measure of aortic stiffness, identify genetic associations and explore links with CVDs. Purpose Identify genetic contributions to pressure-independent aortic stiffness and links to CVDs using large-scale GWAS analysis on the UK Biobank cohort. Methods A pre-trained neural network was used to segment CMR images of participants in the UK Biobank to quantify ascending aorta diameter, which together with contemporaneous systolic and diastolic blood pressure measurements (SBP, DBP, respectively) were used to calculate a pressure-independent measure of aortic stiffness (β0). The measurement assumes an exponential relationship between pressure and aortic diameter. We then performed a GWAS on β0 in 45,789 participants of European ancestry without CVDs. A multi-trait-based conditional &amp; joint analysis (mtCOJO) was performed to estimate genetic effects independent of SBP, DBP and aortic area. We mapped the independent lead variants associated with aortic stiffness at P &amp;lt; 5x10-8 to nearest gene, and characterised shared genetic association across CVDs using Open Targets Platform database. Results The GWAS identified 17 independent lead variants, including 6 that remained significant in the conditional analysis. Four of these lead variants, not previously reported in GWAS of other aortic traits, were located near CTD-2203A3.1, MCF2L, CFDP1 and CDH13 genes (red annotations in the Figure). MCF2L, CFDP1 and CDH13 have been associated with coronary artery disease, and CFDP1 with myocardial infarction and coronary atherosclerosis in previous studies. Conclusion A GWAS of CMR-derived aortic stiffness identified 4 loci distinct from other aortic traits that also associate with other CVDs, suggesting genetic links between aortic stiffness and CVDs. Further analyses are required to explore biological mechanisms underlying these genetic associations.Aortic Stiffness Manhattan Plot

CD14 blockade preserves left ventricular structure and systolic function in a murine model of ST-elevation myocardial infarction

Abstract Background Cluster of differentiation-14 (CD14) facilitates the excessive pro-inflammatory monocyte-macrophage response to myocardial injury. Both acute and chronic infiltration of pro-inflammatory macrophages are implicated in the immunological progression of ischemic heart failure. However, investigation of clinically practicable strategies of CD14 blockade are yet to be reported. Purpose This fully blinded and randomised preclinical study evaluated the efficacy of a neutralising anti-CD14 antibody given at reperfusion in a murine model of reperfused ST-elevation myocardial infarction (STEMI) with key clinical features. Methods Large anterior STEMI was induced in 48 adult mice by left anterior descending coronary artery occlusion for 1 h prior to reperfusion and randomisation to receive anti-CD14 antibody, isotype control (IgG2a) or saline weekly for four weeks (independently blinded). Outcome measures included functional assessments by 9.4T cardiac magnetic resonance (CMR) imaging and ultra-high-resolution echocardiography at 21- and 28-days post-STEMI, respectively. Results Multi-plane short axis CMR at 21-days post-STEMI revealed greater left ventricular (LV) ejection fraction in the anti-CD14 antibody-treated group compared with saline- and isotype-treated controls (30±1 vs 19±1 and 20±1 %, respectively, p&amp;lt;0.001; Figure 1A). CMR also revealed reduced LV dilatation with anti-CD14-treatment compared to control groups (76±5 vs 102±8 and 107±7 µl EDV in saline- and isotype-treated controls, respectively, p&amp;lt;0.05). Parasternal long axis echocardiography at 28 days post-STEMI confirmed that anti-CD14 antibody treatment was associated with greater LV systolic function compared to saline and isotype controls (30±1 vs 24±1 and 25±2 % EF, respectively, p&amp;lt;0.05; Figure 1B). Preservation of LV end-diastolic (86±4 vs 111±6 and 101±5 µl, p&amp;lt;0.01) and end-systolic (61±3 vs 84±5 and 77±5 µl, p&amp;lt;0.01) volumes was also observed with anti-CD14 treatment. Global longitudinal strain (GLS) of the LV was also significantly greater at 28 days post-STEMI with anti-CD14 treatment relative to saline and isotype controls (-8.5±0.4 vs -6.8±0.3 and -6.6±0.4 %, respectively, p&amp;lt;0.05). Conclusion(s) The findings of this fully blinded and randomised preclinical study provide evidence of a clinically practicable strategy of CD14 blockade initiated at reperfusion to mitigate progressive LV systolic dysfunction and dilatation post-STEMI.Figure 1.Functional outcome measures

Prospective assessment of risk factors for appropriate ICD intervention in patients with ischemic cardiomyopathy: results of PARCADIA trial

Abstract Background There is still a big unmet need for better risk stratification tools to identify patients at high risk for sudden cardiac death in the era of primary prevention ICD therapy. Scar burden on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging may be a risk marker for the prediction of ventricular arrhythmia in post-myocardial infarction (MI) patients. Purpose The aim of the PARCADIA trial was to assess whether scar characteristics, determined via LGE-CMR, or other baseline risk markers are associated with appropriate ICD therapy. Methods In this prospective, multi-center, clinical trial, we enrolled post-MI patients with an indication for de novo primary prevention ICD. Main exclusion criteria were indication for cardiac resynchronization therapy and NYHA class IV. Prior to the ICD implantation, LGE-CMR was performed to analyze the amount of scar tissue (LGE core mass + grey zone mass) and LV function / volumes. A 24h Holter recording was performed to collect information on potential triggers like premature ventricular beats (PVB) and sympathetic-vagal balance based on heart rate variability (HRV). Follow-ups were performed in-office every 6 months, including remote monitoring. Appropriate ICD therapy was used as primary endpoint and adjudicated by a clinical event committee. Results 199 patients were enrolled at 5 investigational sites in Europe. Patients mean age was 64.3 years, with a mean LVEF of 27.7 %, timing from the index MI was 9.1 years, and 42.7% received a primary PCI on index MI. After a median follow-up duration of 47.7 months, 23.1% of patients received appropriate ICD therapy. In 135 patients (67.8%), quality of LGE-CMR was sufficient for detailed analysis. The mean LGE core mass (20.5 vs. 19,7 g) and grey zone mass (10.5 vs. 11.4 g) was not different in patients with or without appropriate ICD therapy, also not when corrected for LV mass. However, LVEF (28.5 vs. 32.9 %) was lower, while diastolic myocardial mass (141 vs. 125 g), and end-diastolic volume (265.0 vs. 226.7 ml) were significantly higher in patients with appropriate ICD therapy. On 24h Holter the mean PVB burden (3695 vs. 1643 beats), and non-sustained ventricular tachycardia (12 vs. 0.9), were higher in patients with appropriate ICD therapy, while the HRV (96.1 vs. 113.1 SDNN) was lower. In univariate analysis the variables LVEF, timing to index MI, primary PCI on index MI, PVB burden and HRV appeared to be predictors for appropriate ICD intervention, while in multivariate analysis LVEF and PVB burden remained predictive. Conclusion In post-MI patients with appropriate ICD therapy, scar burden was not different from patients without appropriate ICD therapy. Only LVEF and PVB burden were independent predictors of increased arrhythmogenicity. Improved CMR analysis on scar characteristics (conduction channels) to identify potential arrhythmogenic regions might be the topic for future research.

Impact of left atrial appendage occlusion in atrial flow evaluated through 4D flow cardiac magnetic resonance

Abstract Introduction Device-related thrombus (DRT) and peri-device leak constitute significant complications following left atrial appendage occlusion (LAAO), primarily due to its association with strokes and thromboembolic events. Patient-specific fluid simulations have been employed to explore this hypothesis(1). However, these simulations require detailed anatomical and physiological data, rely on certain assumptions when defining boundary conditions, and involve long computational times. Recently, there has been growing interest in the use of 4D flow cardiac magnetic resonance (CMR) imaging for various cardiovascular diseases, owing to its capability to reproduce blood flow. While its role in the LAAO scenario has been evaluated in silico(2), there are no reported cases of its application in patients undergoing LAAO. Purpose Our objective was to evaluate the impact of LAAO in atrial flow through 4D flow CMR. Methods Five patients undergone LAAO were included in the pilot study. A pre- and 90-days post-procedure 4D flow CMR scans were performed. One of the patients was excluded due to suboptimal image quality. To assess the impact of LAAO on atrial flow dynamics, three parameters were evaluated: a) mean velocity, b) stasis velocity ratio, and c) endothelial cell activation potential (ECAP) index — all associated with an elevated risk of thrombus formation(3,4). Results Baseline and procedural characteristics, along with imaging results, are presented in Table 1. Preprocedural 4D flow CMR for all patients revealed low velocities (Figure 1A) and a high ECAP index (Figure 2A) in the left atrial appendage, indicating flow stasis and an elevated risk of thrombus formation. Successful device implantation was performed in all cases, and no periprocedural complications were detected. Postprocedural 4D flow CMR was feasible in all cases, and no artifacts were detected despite the presence of the LAAO device. An objective increase in velocities and a decrease in the ECAP index were observed in all cases following LAAO. No DRT or ischemic events were reported during follow-up. Conclusions Our preliminary study demonstrates that 4D flow CMR provides valuable information on left atrial flow dynamics following the LAAO procedure. Further studies are warranted to evaluate this promising technique.Table 1.Patient characteristicsFigure 1 and 2.Representative example

Relation of plasma neuropeptide-Y with myocardial function and infarct severity in acute ST-elevation myocardial infarction

Abstract Background Acute myocardial infarction is associated with high levels of cardiac sympathetic stimulation, which leads to the release of the co-transmitter neuropeptide-Y (NPY). NPY acts as a potent vasoconstrictor and an association with increased risk for heart failure and microvascular dysfunction after acute ST-elevation myocardial infarction (STEMI) has been suggested. Purpose This study aims to comprehensively evaluate the association of plasma NPY with myocardial function and infarct severity, visualized by cardiac magnetic resonance (CMR) imaging, in STEMI patients revascularized by primary percutaneous coronary intervention (PCI). Methods In this observational study, we included 260 STEMI patients treated with primary PCI. Plasma NPY concentrations were measured by an immunoassay 24h after PCI from peripheral venous blood samples. Left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), infarct size (IS) and microvascular obstruction (MVO) were determined using CMR imaging 4 days and 4 months after PCI. Results Median plasma concentrations of NPY were 70 [interquartile range (IQR): 35-115] pg/ml. NPY levels above median were significantly associated with lower LVEF (48% vs. 52%, p=0.004), decreased GLS (-8.8% vs. -12.6%, p&amp;lt;0.001) and larger IS (17% vs. 13%, p=0.041) in the acute phase after infarction as well as in the chronic stage (LVEF: 50% vs. 52%, p=0.030, GLS: -10.5 vs. -12.9, p&amp;lt;0.001, IS: 13% vs. 10%, p=0.011). In addition, NPY levels were significantly related to presence of MVO (58% vs. 52%, p=0.041). Moreover, in multivariable linear regression analysis, NPY remained significantly associated with all investigated CMR parameters (LVEF: p&amp;lt;0.001, GLS: p&amp;lt;0.001, IS: p=0.003, MVO: p=0.042) independent of other established clinical variables including high-sensitivity cardiac troponin T, pre-interventional TIMI flow 0 and left anterior descending artery as culprit lesion location. Conclusion High plasma levels of NPY, measured 24h after STEMI, were independently associated with lower LVEF, decreased GLS, larger IS as well as presence of MVO, indicating plasma NPY as a valuable biomarker for optimized risk stratification.

Diagnostic and prognostic value of ECG-predicted hypertension mediated left ventricular hypertrophy using machine learning

Abstract Background Hypertension is the commonest cause of left ventricular hypertrophy (LVH). Using cardiac magnetic resonance (CMR) imaging, four distinct hypertension mediated LVH phenotypes have been reported: normal LV, LV remodelling, eccentric LVH and concentric LVH. Early detection of hypertensives with LVH can enable timely initiation of therapy however a CMR based screening strategy is costly, particularly in low resource settings. The electrocardiogram (ECG) is an inexpensive screening tool and can detect LVH but its capacity to discriminate between the 4 phenotypes is unknown. Purpose To classify hypertension mediated LVH phenotypes from the ECG using machine learning (ML) and test for associations of ECG predicted LVH phenotypes with incident cardiovascular outcomes. Methods ECG markers with a known physiological association with LVH (including QRS markers, Sokolow-Lyon, and Cornell) were extracted from the 12-lead ECG of 20,439 hypertensive participants in UK Biobank. Three classification models, logistic regression, support vector machine (SVM) and random forest, were trained in 80% of the participants using extracted ECG markers and clinical variables. The remaining 20% individuals were included in the test set for performance measurement. External validation was sought in 877 hypertensives from the Study of Health in Pomerania (SHIP). Subsequently, we tested for associations between the four ECG-predicted LVH phenotypes and incident major adverse cardiovascular events (MACE) and heart failure using Cox proportional hazard regression in the UK Biobank test set with median follow-up of 4.2 years. Results Among UK Biobank participants (mean age ± standard deviation 65 ± 7.4 years), 23,190 had normal LV, 894 LV remodelling, 218 eccentric and 103 concentric LVH. Classification performance of the three models was comparable, but SVM showed consistent results (accuracy 0.79, sensitivity 0.59, specificity 0.87, AUC 0.69) and superior prediction of eccentric LVH (AUC 0.86). In SHIP (55 ± 12.7 years), 704 had normal LV, 134 LV remodelling, 12 eccentric and 24 concentric LVH. In the external validation performed in SHIP, SVM had accuracy of 0.75 (sensitivity 0.51, specificity 0.85, AUC 0.65), with superior prediction of eccentric LVH (AUC 0.76), as shown in Figure 1. Ventricular rate and QRS amplitude (P&amp;lt;0.001) were the features most strongly associated with LVH. In the test set of UK Biobank, setting normal LV as the reference group, the ECG predicted eccentric LVH group was associated with heart failure (Hazard Ratio 3.42, confidence interval 1.06-9.86), there were no associations with MACE (Figure 2). Conclusions ECG-based ML classifiers were able to discriminate the four hypertension mediated LVH phenotypes with external validation demonstrating robustness. This automated approach enhances capabilities of non-specialists and potentially represents an accessible screening strategy for the early detection of hypertensives with LVH.

Latent cytomegalovirus infection associates with impairments in myocardial reperfusion, left-ventricular function, and quality of life after ST-elevation myocardial infarction

Abstract Introduction Cytomegalovirus (CMV) is a ubiquitous herpesvirus affecting the majority of adults in European countries. CMV influences T-lymphocyte biology throughout life. We have previously associated CMV status with adverse left ventricular (LV) remodeling after ST-elevation myocardial infarction (STEMI) in a single-centre study. In this study, we aimed to assess the external validity of these findings. Methods This study is a retrospective analysis of 354 patients presenting with STEMI, who were recruited to A Trial of Low-Dose Adjunctive Alteplase During Primary PCI (T-TIME) and had blood samples archived. The participants underwent immediate coronary angiography and percutaneous coronary intervention (PCI), serial cardiovascular magnetic resonance (CMR) imaging at 2-7 days and 3 months post-STEMI, and serial assessment of health-related quality of life with the standardised EQ-5D visual analogue scale (VAS). CMV IgG titre was measured in cryopreserved samples from each patient, and patients were categorised as CMV negative, low-positive or high-positive. All analyses were adjusted for infarct location. Results Of 354 patients, 175 (49.4%) were CMV IgG titre negative, 89 (25.1%) were low-positive and 90 (25.4%) were high-positive. CMV+ patients were older (62.5 vs 58.7 years) and more likely to be non-White (6.7% vs 2.3%). CMV+ patients displayed several adverse outcomes. First, myocardial reperfusion was impaired. Thrombolysis in myocardial infarction (TIMI) flow grade 3 after PCI, indicating complete reperfusion, was less common in CMV+ patients (76.0% vs 84.6%; p=0.042). CMV+ patients also had a higher TIMI frame count after PCI (p=0.021), and non-significantly less ST-segment resolution at 60 minutes (38.8% vs 48.4%; p=0.066). Impaired myocardial reperfusion appeared to lead to impaired LV function, with LV ejection fraction (LVEF) measured on early CMR lower in CMV+ patients (42.6% vs 45.3%, p=0.004). At 3 months, LV function remained impaired in CMV+ patients (LVEF: 47.8% vs 49.7%; p=0.035). This was mirrored by CMV+ patients displaying higher NT-pro BNP levels at 2-7 days (1381 vs 1172pg/mL, p=0.097) and 3 months (575 vs 338pg/mL, p=0.021). Finally, impaired LV function appeared to affect quality of life. Over 3 months, in contrast to CMV-negative patients, those with the highest CMV IgG experienced almost no improvement in quality of life, measured by change in the EQ-5D VAS (negative: +9.93; high-positive: +0.70; p=0.0002). Conclusion CMV+ patients with STEMI experience worse outcomes, with impaired reperfusion, persistently reduced LV function and less improvement in health-related quality of life over 3 months. We hypothesise that the effect of CMV is mediated through immune activation. Future research should explore the mechanisms by which CMV-specific lymphocytes interact with myocardial reperfusion and repair post-STEMI.

Cocoa flavanols alleviate early diastolic dysfunction by decreasing left atrial volume in healthy elderly individuals

Abstract Background Enlargement of the left atrium (LA) predicts future cardiovascular events. Current guidelines recommend cocoa flavanol (CF) intake as it provides cardiovascular and metabolic benefits, although underlying mechanisms are not fully revealed. In this study, we hypothesized that CF intake reverses LA enlargement as a surrogate marker for diastolic dysfunction in elderly individuals without cardiovascular diseases. Methods and Results In a randomized, double-blinded trial, we investigated the effects of CF on systolic and diastolic heart function in healthy elderly individuals. Precise assessment of left-atrial and left-ventricular volume as well as strain rates, all together as emblems of early subclinical cardiac impairment, and markers of systolic function were measured by high-resolution cardiac magnetic resonance (CMR) imaging before and after CF intake. Sixty-three participants (59% male) aged ≥ 55 years received either 500 mg CF (n=30) or a placebo (n=33) twice daily for 30 days. CF counteracted subclinical cardiac dysfunction, evidenced by a reduction in maximal LA volume and LA volume index by 12.6±3.5% (p=0.0063 and p=0.0067) and LV end-diastolic volume (LVEDV) and LVEDV index by ~4.9±1.9% (p=0.049 and p=0.0413). CF intake did not influence strain, strain rate, and systolic function parameters, while the systolic blood pressure decreased by 7 mmHg [~4.7±1.9% (p=0.04)]. Conclusion We provide evidence that CF intake mitigates early changes of diastolic dysfunction and improves cardiovascular health by reversing left atrial and left ventricular remodeling. Cocoa flavanol consumption may prevent age-related cardiac changes in healthy elderly individuals and promote a health span free from cardiovascular diseases.

Non-lipid metabolomic biomarkers are associated with adverse cardiac remodelling and cardiovascular outcomes

Abstract Background Metabolomics is the detailed profiling of circulating metabolites including carbohydrates, lipids, amino and fatty acids, and ketones, all of which are substrates used in energy metabolism by cardiomyocytes. Purpose The role of cholesterol fractions with cardiovascular risk is well-established. This novel study examines the association between non-lipid circulating metabolites and markers of cardiac remodelling as assessed by cardiovascular magnetic resonance (CMR) imaging. Metabolites associated with adverse remodelling were taken forward to examine their impact on incident cardiovascular disease (CVD); ischaemic heart disease (IHD) and heart failure (HF). Methods This study used data from the UK Biobank. After exclusions (prevalent IHD, HF; outliers), there were a maximum of 34,727 individuals for CMR analyses and 262,536 individuals for incident CVD analysis. For CMR analyses, outcome variables were LV end-diastolic volume (EDV), LV mass, LV mass:volume ratio (MVR), LV global longitudinal strain (GLS) and native T1. Separate regression models were built for each of the 40 scaled metabolite biomarkers. Each model incorporated one metabolite at a time with additional covariates: age, sex, ethnicity, systolic blood pressure, cholesterol medication use, type 2 diabetes, dietary intake, smoking status, fasting time, and time between recruitment and CMR examination. A Bonferroni-corrected significance threshold of 2.4x10-4 was used. To account for correlation between metabolites, Lasso regression with 10 fold cross-validation to identify the most important predictors was performed for LV MVR, LV GLS and native T1 whereby all metabolites and above covariates were included in the model. Metabolite predictors of adverse remodelling were included in an adjusted logistic regression model with incident CVD as an outcome. Results Metabolites demonstrating significant (p &amp;lt; 2.4x10-4) associations with CMR parameters are presented in Fig 1. For higher LV MVR and more positive LV GLS, the metabolites with the largest effect were monounsaturated fatty acids and glycoprotein acetyls. Higher omega-6:omega-3 ratio was associated with higher T1 values. The Lasso model identified 8 important predictors for adverse cardiac remodelling. Of these, two were routine biomarkers (creatinine, glucose). Of the remainder, monounsaturated fatty acids, glycoprotein acetyls and apolipoprotein B:apolipoprotein A1 ratio were significantly associated with increased risk of incident CVD (Fig 2). Current evidence regarding monounsaturated fatty acids in CVD is mixed. Glycoprotein acetyls are implicated in vascular inflammation. Apolipoproteins are thought to be a potential therapeutic target for CVD risk reduction. Conclusion This study demonstrates a role of non-lipid metabolites on subclinical CVD as assessed by adverse remodelling with CMR as well as associations with incident CVD. We highlight potential novel biomarkers for identification of CVD.Metabolite association with LV MVR/GLSMetabolite association with incident CVD

Cardiac magnetic resonance T1 imaging for the diagnosis of cardiac amyloidosis among patients with symptomatic heart failure

Abstract Background Cardiac amyloidosis (CA) is a significant cause of heart failure in elderly patients. However, specific signs in cardiac imaging are lacking, hence bone scintigraphy in combination with screening for monoclonal protein, or myocardial biopsy is required for the diagnosis. Cardiac magnetic resonance (CMR) imaging with T1 mapping is a promising diagnostic tool, which may allow to differentiate causes of left ventricular (LV) hypertrophy, particularly CA. Purpose The aim of this study was to test the diagnostic accuracy of T1 mapping for the diagnosis of CA in elderly patients with symptomatic heart failure and red flags for CA. Methods We prospectively enrolled 120 patients aged above 60 years with symptomatic heart failure NYHA II-IV, LV ejection fraction ≥ 40%, increased LV wall thickness of ≥ 12 mm end-diastolic on echocardiography, and elevated cardiac biomarkers (N-terminal pro-B-type natriuretic peptide (NT-proBNP) ≥ 1,000 ng/L, high-sensitivity cardiac troponin T (hs-cTnT) ≥ 14 ng/L). All patients underwent standardized quantitative CMR with a 3.0T scanner. 99mTc-DPD bone scintigraphy, blood screening for monoclonal protein, and, where applicable, cardiac biopsy, were performed as reference methods in all patients. Primary endpoint was diagnostic accuracy of native T1 mapping for the diagnosis of CA. Results 112 patients were included in the final analysis. Median age was 81.0 years (interquartile range 74.0–85.0 years), and 45% were female. CA was diagnosed in 38 patients (34%), of which 32 suffered from a Transthyretin (ATTR) and 6 patients from light chain (AL) amyloidosis. The areas under the receiver operating characteristic curves for native T1 were 0.713, 0.772, 0.836 for global, septal short-axis (SAX), and septal 4-chamber (4Ch) view measurements. The corresponding value of extracellular volume fraction (ECV) was 0.904 (Figure 1). Based on these results, we developed a new diagnostic algorithm for the diagnosis of CA including T1 septal 4Ch and ECV, with a sensitivity and positive predictive value of both 92.9% and a specificity and negative predictive value of 95.8% (Figure 2). Thereby, contrast application can be avoided in 33% of patients. A definite diagnosis could be provided in 81%. Conclusion CMR with T1 imaging provides a high diagnostic accuracy to diagnose CA in patients with symptomatic heart failure at risk for CA. These data may help to identify underlying causes in heart failure which require specific treatment. An earlier diagnosis of CA may improve outcome of these patients.Figure 1Figure 2

Using deep learning to predict cardiovascular magnetic resonance findings from echocardiography videos

Abstract Background Echocardiography is the most common modality for assessing cardiac structure and function. While cardiac magnetic resonance (CMR) imaging is less accessible, CMR can provide unique tissue characterization including late gadolinium enhancement (LGE), T1 and T2 mapping, and extracellular volume (ECV) which are associated with tissue fibrosis, infiltration, and inflammation. While deep learning has been shown to uncover findings not recognized by clinicians, it is unknown whether CMR-based tissue characteristics can be derived from echocardiography videos using deep learning. Purpose To assess the performance of a deep learning model applied to echocardiography to detect CMR-based parameters. Methods In a retrospective single-center study, adult patients with CMRs and echocardiography studies within 30 days were included. A video-based convolutional neural network was trained on echocardiography videos to predict CMR-derived labels including WMA presence, LGE presence, and abnormal T1, T2 or ECV across echocardiography views. The model performance was evaluated in a held-out test dataset not used for training. Results The study population included 1,453 adult patients (mean age 56±18 years, 42% female) with 2,556 paired echocardiography studies occurring on average 2 days after CMR (interquartile range 2 days prior to 6 days after). The model had high predictive capability for presence of WMA (AUC 0.873 [95%CI 0.816-0.922]), however, the model was unable to reliably detect the presence of LGE (AUC 0.699 [0.613-0.780]), native T1 (AUC 0.614 [0.500-0.715]), T2 0.553 [0.420-0.692], or ECV 0.564 [0.455-0.691]). Conclusions Deep learning applied to echocardiography accurately identified CMR-based WMA, but was unable to predict tissue characteristics, suggesting that signal for these tissue characteristics may not be present within ultrasound videos.Central Figure -Study Pipeline-

The relative importance of ischaemia and scar in the genesis of ventricular arrhythmia in ischaemic cardiomyopathy

Abstract Background Ventricular arrhythmias are a leading cause of death in patients with ischaemic cardiomyopathy (ICM). Ischaemia and scar are thought to contribute to arrhythmogenesis; as scar is considered fixed, strategies to reduce ischaemia such as revascularisation are undertaken to attempt to reduce risk, despite limited evidence behind this practice. Purpose The study rationale was to understand the relative contributions of ischaemia and scar on the genesis of arrhythmia in an ICM population, by undertaking a detailed assessment of arrhythmic substrate in a highly characterised population and secondly by validating these findings in a large cohort. Methods We assessed the relationship between scar, ischaemic burden and impact of ischaemia modulation via revascularisation on the arrhythmic substrate (study 1) and major arrhythmic events (study 2). S1: Patients were eligible for enrolment if they had an LVEF≤40%, extensive coronary disease (BCIS Jeopardy Score (JS) ≥6) and were due to undergo CABG or PCI. Arrhythmic substrate was characterised by the LV activation recovery interval (ARI) dispersion recorded by electrocardiographic imaging (ECGi). Scar and ischaemic burden were assessed via stress perfusion cardiac magnetic resonance (pCMR) imaging, calculated as a percentage of total LV myocardial volume. ECGi and pCMR were repeated 3 months post revasc. S2: Arrhythmia data were collected from device interrogation reports and blinded core lab analyses performed of CMR scans and angiograms of patients enrolled in the REVIVED-BCIS2 trial. Extent of revasc (quantified by change in JS/baseline JS) was used to estimate change in ischaemic burden. The primary outcome was death or aborted sudden death. Results S1: 30 patients were recruited; age 67±10 years, 87% male, BMI 28±5. Baseline LV ARI dispersion at rest was correlated with scar burden (r=0.37, p=0.04) but not ischaemic burden (r=0.25,p=0.21). Changes in metrics are shown(Table 1). Ischaemic burden reduced after revascularisation. Delta ischaemic burden was correlated with delta LV ARI dispersion (r=0.51, p=0.007 unadjusted). S2: Data was collected on 479 patients from REVIVED-BCI2 who underwent CMR; age 69±9 yrs, 88% male, BMI 28±6, LVEF 26±8%. 237 were randomised to PCI and 242 to OMT; no difference in rates of all-cause death, CV death, aborted sudden death, appropriate device therapy or arrhythmia was identified between the groups. Scar burden was associated with death or aborted sudden death, extent of revascularisation was not(Figure 1). Conclusion In our studies, the volume of scar was strongly related to both the arrhythmic substrate and occurrence of arrhythmic events. Whilst ischaemia reduction affected the arrhythmic substrate, this did not translate to a reduction in clinical events. These findings suggest that scar burden, rather than ischaemia reduction by revascularisation, should be the focus of risk stratification and therapeutic decision making in patients with ICM.Table 1Figure 1

Changes in peak oxygen consumption on excercise and cardiomyopathy disease stage in Fabry disease

Abstract Background Fabry disease (FD) is an X-linked lysosomal storage disorder manifesting as deficiency in the enzyme α-Galactosidase A (1) resulting in multi-organ accumulation of globotriaosylceramide (Gb3) (2) This causes predominantly cardiac, renal and cerebrovascular manifestations. Shortness of breath and exercise intolerance are common and can be related to multiple underlying mechanisms. Cardiopulmonary exercise testing (CPEX) quantifies aerobic fitness, functional capacity, chronotropic and haemodynamic response to exercise, and attributes effort intolerance to different aetiologies, including impaired cardiac and respiratory function. Purpose We hypothesise that there is progressive effort intolerance that reflects continual cardiac Gb3 accumulation, becoming common during myocardial hypertrophy and disabling in the fibrosis and inflammation stage. The aims of this study were to ascertain frequency and severity of exercise intolerance in FD by investigating the relationship between peak maximal oxygen uptake (VO2 max) and cardiac disease stage, quantified based on a four-point scale, as proposed in published literature (3). Methods This was a retrospective review of adults with FD and exercise intolerance attending a specialist clinic who had undergone either CPEX or six-minute walk testing (6MWT) in those less mobile. Biochemical, cardiac magnetic resonance (CMR) imaging and transthoracic echocardiographic (TTE) data were also collected. Results N=54 patients underwent CPEX and N=35 patient underwent 6MWT. Estimated peak VO2 max was calculated using 6MWD in those undergoing 6MWT. Median age was 54 (IQR 40-62) years and 53% were male. Patients were equally distributed across disease stage (1-4). There were significant trends in age (increasing) and gender (male predominance) from stage 1-4. Age/sex-normalised peak VO2 max values were calculated as per published literature due to the confounding effect of age and male gender. Mean normalised VO2 max was 35.5ml/kg/min for the cohort, an underperformance of 12.3 ± 8.0 ml/kg/min. The magnitude of underperformance began from stage 1 (no cardiomyopathy) and increased with each stage (Figure 1). Impairments in renal (creatinine and albumin: creatinine ratio) and cardiac biomarkers (troponin and N-terminal pro brain natriuretic peptide) was associated with reduced VO2 max (Table 1). Increased indexed left ventricular mass on CMR and impairments in atrial volume and function on TTE were also associated with a reduction in VO2 max (Table 1). Conclusion This study is the first of its kind to demonstrate impairments in peak aerobic capacity in adults with FD and no cardiomyopathy (stage 1) which impairs further with cardiac disease stage. Future work should focus on how disease-modifying therapy can target this using VO2 as an endpoint and marker of response.Normalised peak VO2 max + disease stageVO2 max and blood / imaging parameters