Routine Cardiovascular Magnetic Resonance Research Articles

Delayed 3D IR FLASH for airway imaging in children: more than myocardial fibrosis assessment

BackgroundTo investigate the ability of a delayed respiratory-navigated, electrocardiographically-gated three-dimensional inversion recovery-prepared flash low angle shot (3D IR FLASH) sequence to evaluate the lower airways in children undergoing routine cardiovascular magnetic resonance (CMR). MethodsThis retrospective study included pediatric patients (0-18 years) who underwent clinical CMR where a delayed 3D IR FLASH sequence was performed between July 2020 and April 2021. The airway image quality and extent of lower airway visibility was graded by two blinded readers using a four-point ordinal scale (0-3). Lower airway anatomical variants and abnormalities were recorded. Results180 patients were included with a median age of 11.7 (4.6-15.3) years. 51/180 (28%) were under general anesthesia (GA). Overall, the median grading of airway image quality was 3 (2-3) and extent of lower airway visibility was 3 (3-3). Interrater agreement was almost perfect (κ = 0.867 and κ = 0.956, respectively). Image quality correlated with extent of lower airway visibility (r = 0.62, p < 0.01). Delayed 3D IR FLASH was able to characterize the segmental bronchi in 137/180 (76%) and lobar bronchi in 172/180 (96%) of patients. Lower airway abnormalities were identified in 37/180 (21%) of patients and in 33/129 (26%) with congenital heart disease (CHD). Identified abnormalities included tracheobronchial branching anomalies in 6/180 (3%), abnormal tracheobronchial situs in 6/180 (3%), and extrinsic vascular compression in 25/180 (14%). ConclusionsDelayed 3D IR FLASH has excellent performance for evaluation of the lower airway anatomy and can simultaneously assess for myocardial late gadolinium enhancement. Lower airway abnormalities are not infrequently seen in children undergoing routine CMR for CHD.

A Non-Invasive Technique to Unveil Renal Implications in Anderson-Fabry Disease.

Anderson-Fabry disease (AFD) is a rare genetic disorder characterized by a deficiency of α-galactosidase A activity and the accumulation of glycosphingolipids in tissues, which leads to multiorgan damage. Cardiovascular magnetic resonance (CMR) and the T1 mapping technique are essential tools for the assessment of AFD cardiac involvement. Moreover, the T1 mapping technique has proved to be a successful non-invasive method for the early detection of patients most at risk for kidney disease. We evaluated the application of MRI in patients with AFD to assess renal involvement. We conducted a retrospective analysis of 19 patients (Group A) with histologically proven AFD who underwent routine CMR examinations for the evaluation of cardiac involvement, selecting specific sequences that also showed the left kidney, compared to a control population (Group B, 19 patients) without kidney disease. A Spearman's rank-order correlation was run to assess the relationship between the T1 mapping values of the heart and kidney in Group A and between the kidneys of Groups A and B. There was a positive correlation between the heart and kidney T1 values in Group A (rho = 0.32). More interestingly, we observed a negative correlation between the kidney values of both groups (Group A mean 1284 ± 137 ms, Group B mean 1073 ± 57 ms, rho = -0.38), which is probably related to the presence of microvascular damage and infiltrates in the kidneys of AFD patients. To our knowledge, these results are the first to highlight the key value of T1 mapping in assessing pathological changes and aiding in the non-invasive diagnosis of renal involvement in AFD.

Risk factors for raised left ventricular filling pressure by cardiovascular magnetic resonance: Prognostic insights.

Cardiovascular magnetic resonance (CMR) imaging shows promise in estimating pulmonary capillary wedge pressure (PCWP) non-invasively. At the population level, the prognostic role of CMR-modelled PCWP remains unknown. Furthermore, the relationship between CMR-modelled PCWP and established risk factors for cardiovascular disease has not been well characterized. The main aim of this study was to investigate the prognostic value of CMR-modelled PCWP at the population level. Employing data from the imaging substudy of the UK Biobank, a very large prospective population-based cohort study, CMR-modelled PCWP was calculated using a model incorporating left atrial volume, left ventricular mass and sex. Logistic regression explored the relationships between typical cardiovascular risk factors and raised CMR-modelled PCWP (≥15mmHg). Cox regression was used to examine the impact of typical risk factors and CMR-modelled PCWP on heart failure (HF) and major adverse cardiovascular events (MACE). Data from 39163 participants were included in the study. Median age of all participants was 64years (inter-quartile range: 58 to 70), and 47% were males. Clinical characteristics independently associated with raised CMR-modelled PCWP included hypertension [odds ratio (OR) 1.57, 95% confidence interval (CI) 1.44-1.70, P<0.001], body mass index (BMI) [OR 1.57, 95% CI 1.52-1.62, per standard deviation (SD) increment, P<0.001], male sex (OR 1.37, 95% CI 1.26-1.47, P<0.001), age (OR 1.33, 95% CI 1.27-1.41, per decade increment, P<0.001) and regular alcohol consumption (OR 1.10, 95% CI 1.02-1.19, P=0.012). After adjusting for potential confounders, CMR-modelled PCWP was independently associated with incident HF [hazard ratio (HR) 2.91, 95% CI 2.07-4.07, P<0.001] and MACE (HR 1.48, 95% CI 1.16-1.89, P=0.002). Raised CMR-modelled PCWP is an independent risk factor for incident HF and MACE. CMR-modelled PCWP should be incorporated into routine CMR reports to guide HF diagnosis and further management.

Enhanced Myocardial Tissue Visualization: A Comparative Cardiovascular Magnetic Resonance Study of Gradient-Spin Echo-STIR and Conventional STIR Imaging.

This study is aimed at evaluating the efficacy of the gradient-spin echo- (GraSE-) based short tau inversion recovery (STIR) sequence (GraSE-STIR) in cardiovascular magnetic resonance (CMR) imaging compared to the conventional turbo spin echo- (TSE-) based STIR sequence, specifically focusing on image quality, specific absorption rate (SAR), and image acquisition time. In a prospective study, we examined forty-four normal volunteers and seventeen patients referred for CMR imaging using conventional STIR and GraSE-STIR techniques. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), image quality, T2 signal intensity (SI) ratio, SAR, and image acquisition time were compared between both sequences. GraSE-STIR showed significant improvements in image quality (4.15 ± 0.8 vs. 3.34 ± 0.9, p = 0.024) and cardiac motion artifact reduction (7 vs. 18 out of 53, p = 0.038) compared to conventional STIR. Furthermore, the acquisition time (27.17 ± 3.53 vs. 36.9 ± 4.08 seconds, p = 0.041) and the local torso SAR (<13% vs. <17%, p = 0.047) were significantly lower for GraSE-STIR compared to conventional STIR in short-axis plan. However, no significant differences were shown in T2 SI ratio (p = 0.141), SNR (p = 0.093), CNR (p = 0.068), and SAR (p = 0.071) between these two sequences. GraSE-STIR offers notable advantages over conventional STIR sequence, with improved image quality, reduced motion artifacts, and shorter acquisition times. These findings highlight the potential of GraSE-STIR as a valuable technique for routine clinical CMR imaging.

The epicardial adipose tissue confined in the atrioventricular groove can be used to assess atrial adipose tissue and atrial dysfunction in cardiac magnetic resonance imaging.

The growing interest in epicardial adipose tissue (EAT) as a biomarker of atrial fibrillation is limited by the difficulties in isolating EAT from other paracardial adipose tissues. We tested the feasibility and value of measuring the pure EAT contained in the atrioventricular groove (GEAT) using cardiovascular magnetic resonance (CMR) imaging in patients with distinct metabolic disorders. CMR was performed on 100 patients from the MetaCardis cohort: obese (n = 18), metabolic syndrome (MSD) (n = 25), type-2 diabetes (T2D) (n = 42), and age- and gender-matched healthy controls (n = 15). GEAT volume measured from long-axis views was obtained in all patients with a strong correlation between GEAT and atrial EAT (r = 0.95; P < 0.0001). GEAT volume was higher in the three groups of patients with metabolic disorders and highest in the MSD group compared with controls. GEAT volume, as well as body mass and body fat, allowed obese, T2D, and MSD patients to be distinguished from controls. GEAT T1 relaxation and peak longitudinal left atrial (LA) strain in CMR were decreased in T2D patients. Logistic regression and random forest machine learning methods were used to create an algorithm combining GEAT volume, GEAT T1, and peak LA strain to identify T2D patients from other groups with an area under curve (AUC) of 0.81 (Se: 77%, Spe: 80%; 95% confidence interval 0.72-0.91, P < 0.0001). Atrioventricular groove adipose tissue characteristics measured during routine CMR can be used as a proxy of atrial EAT and integrated in a multi-parametric CMR biomarker for early identification of atrial cardiomyopathy.

Diabetic atrial cardiomyopathy can be identified by multiparametric mri MRI associating atrio-ventricular groove adipose tissue and left atrial strain profiles

Abstract Background Epicardial adipose tissue (EAT) is tightly associated with neighboring myocardium with free diffusion between the two tissues of fatty acid, peptides and adipokines. In specific circumstances EAT can favors myocardial remodeling and, for instance, contribute to the risk of atrial fibrillation (AF). Thereby, there is a growing interest for EAT as a biomarker of AF however, which is limited by difficulties of delineation of EAT vs. other paracardial adipose tissues. The atrio-ventricular groove adipose tissue (GEAT) has been proven to be pure epicardial adipose tissue. Purpose We tested the feasibility and value of measuring pure EAT of the atrio-ventricular groove (GEAT) using routine cardiovascular magnetic resonance imaging (CMR) in a cohort of patients with distinct metabolic disorders and studied its correlates to determine a CMR cardiometabolic score. Methods One hundred patients from the METACARDIS cohort (EU FP7) who had MRI, all in sinus rhythm and without overt clinical heart disease, were divided into 4 groups based on distinct metabolic profiles: metabolic syndrome (MSD, n=25), severe obesity (SO, BMI ≥ 35 kg/m2, n=18), type-2 diabetes (T2D, n=42) and healthy controls (n=15). Atrioventricular groove EAT volume was measured from cine SSFP MRI images in four-, three-, two-chamber and short-axis views; atrial EAT volume was measured from four- and two-chamber views. Native T1-mapping values of EAT at the anterior atrioventricular groove excluding the coronary vessels were measured from the MOLLI sequence (basal short-axis slice). Results CMR was performed in 100 patients from the MetaCardis cohort. GEAT volume measured from end-diastolic long axis views was obtained in all patients with a high correlation between GEAT and atrial EAT (r=0.95; P&amp;lt;0.0001). GEAT volume was higher in the 3 groups of patients with metabolic disorders and highest in MSD. Together with age, body mass, fat distribution, GEAT volume allowed to distinguish obese, T2D and MSD from controls. T2D patients were uniquely characterized in CMR by decreased GEAT T1 relaxation and decreased peak longitudinal left atrial strain. We developed a CMR score by logistic regression and Random Forest machine-learning algorithm combining GEAT volume, T1 and peak LA strain that identified T2D patients with an AUC of 0.81 (Se:77%, Spe:80%; 95%-CI 0.72–0.91, p &amp;lt;0.0001). Conclusion The epicardial adipose tissue of the AV groove measured by CMR can be used as the proxy of atrial EAT and, in combination with atrial strain and T1 relaxation, allows the early identification of the atrial cardiomyopathy associated with diabetes. There is diagnostic value of a multiparametric CMR approach for the detection of subclinical atrial cardiomyopathy and potentially to identify patients at risk of atrial fibrillation and stroke.

Abstract 15044: The Relationship of Pericardial Fat With Metabolic Change and Myocardial Remodelling Following Bariatric Surgery

Introduction: Pericardial fat is a cardiometabolic risk factor that can be quantified from routine cardiovascular magnetic resonance (CMR) studies. However the extent to which this is modifiable, and its relationship with cardiometabolic markers remains unclear. Aims: Determine the effect of bariatric surgery on pericardial fat and associate with cardiometabolic improvements post-surgery. Methods: Thirty-eight people referred for bariatric surgery were assessed pre-operatively using CMR, blood biomarkers and anthropometry. Six months post-operatively, twenty-seven participants underwent paired follow-up assessments. Pericardial fat was quantified manually from routine short axis cine stacks by a single blinded clinical observer. Linear regression was used to assess the association of pericardial fat volume and cardiometabolic parameters, at baseline and changes pre- vs post-surgery. Results: At baseline, pericardial fat volume was associated with multiple cardiometabolic parameters including weight (r=0.46 p=0.004), fasting insulin (r=-0.46, p=0.007) hepatic fat concentration (Hepafat) (r=0.37 p=0.029) and LV mass (r=0.38, p=0.019). Pericardial fat remained independently associated with waist circumference after adjusting for the above (β=0.68, 95% CI: 1.24,9.23, p=0.012). At 6 months post-bariatric surgery pericardial adipose tissue reduced by an average of 29% (95% CI: -21-36%, p&lt;0.001). This change was associated with improvements in fasting insulin levels even after adjusting for changes in weight, Hepafat and LV mass (β=0.72, 95% CI: 0.15, 0.70, p=0.005). Conclusion: Pericardial fat in obesity associates with multiple adverse cardiometabolic parameters, including waist circumference. Bariatric surgery causes a significant reduction in pericardial fat which associates with reduced insulin resistance, providing a potential modifiable mechanism to reduce cardiovascular risk in patients living with obesity.

Association of AI derived right ventricular function with all-cause mortality in patients referred for routine cardiovascular magnetic resonance

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Wellcome/EPSRC Centre for Medical Engineering at King’s College London (WT 203148/Z/16/Z), the National Institute for Health Research (NIHR) Cardiovascular MedTech Co-operative award to the Guy’s and St Thomas’ NHS Foundation Trust, and the London AI Center, funded through the UK Research and Innovation (UKRI) and the Department of Health and Social Care (DHSC), Office of Life Sciences, delivered through Innovate UK. Background Right ventricular (RV) function is an important prognostic marker in assessment of cardiovascular disease. Artificial Intelligence (AI) based quantification of RV function has been validated against ground truth metrics however their relationship to outcomes is not yet well defined. Purpose To evaluate the relationship between RV biomarkers obtained using our validated AI tool, AI-CMRQC with all-cause mortality in patients who underwent routine cardiovascular magnetic resonance (CMR). Methods 3,108 routine clinical CMR scans, performed between 2016 and 2020 were retrospectively analysed using AI-CMRQC (1) to obtain RV function parameters of end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF). All-cause mortality and date of death were obtained from hospital electronic records and Personal Demographics Service from the Office for National Statistics (ONS). Cox proportional hazard risk models were used to derive hazard ratios for measuring association between RV function and all-cause mortality. All variables were stratified based on upper or lower limits of reference values (2), RVEF &amp;lt;50% or &amp;gt;50%, EDV &amp;gt;217ml males, &amp;gt;175ml females, ESV &amp;gt;91ml males, &amp;gt;75ml females, SV &amp;lt;71ml males, &amp;lt;56ml females. Results The distribution of mean values (±SD) of RV parameters were EDV 166.14 ± 0.83ml, ESV 77.83 ± 0.57ml, SV 88.3 ± 0.45ml and EF 55.9 ± 0.17%. The median follow up duration was 3.4 years. On univariate analysis, ejection fraction [Hazard Ratio (HR) 2.903 (95% Confidence Interval [CI] 2.197 to 3.834] and stroke volume [HR 3.385 (95% CI 2.534 to 4.522)] were significant predictors of mortality. After adjustment for covariates of left ventricular function (LVEF, LVEDV, LVESV) RVEF remained an independent predictor of mortality. Conclusions Automated RV ejection fraction is significantly associated with all-cause mortality in patients undergoing routine CMR.

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

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

Pulmonary transit time of cardiovascular magnetic resonance perfusion scans for quantification of cardiopulmonary haemodynamics.

Pulmonary transit time (PTT) is the time blood takes to pass from the right ventricle to the left ventricle via pulmonary circulation. We aimed to quantify PTT in routine cardiovascular magnetic resonance imaging perfusion sequences. PTT may help in the diagnostic assessment and characterization of patients with unclear dyspnoea or heart failure (HF). We evaluated routine stress perfusion cardiovascular magnetic resonance scans in 352 patients, including an assessment of PTT. Eighty-six of these patients also had simultaneous quantification of N-terminal pro-brain natriuretic peptide (NTproBNP). NT-proBNP is an established blood biomarker for quantifying ventricular filling pressure in patients with presumed HF. Manually assessed PTT demonstrated low inter-rater variability with a correlation between raters >0.98. PTT was obtained automatically and correctly in 266 patients using artificial intelligence. The median PTT of 182 patients with both left and right ventricular ejection fraction >50% amounted to 6.8 s (Pulmonary transit time: 5.9-7.9 s). PTT was significantly higher in patients with reduced left ventricular ejection fraction (<40%; P < 0.001) and right ventricular ejection fraction (<40%; P < 0.0001). The area under the receiver operating characteristics curve (AUC) of PTT for exclusion of HF (NT-proBNP <125 ng/L) was 0.73 (P < 0.001) with a specificity of 77% and sensitivity of 70%. The AUC of PTT for the inclusion of HF (NT-proBNP >600 ng/L) was 0.70 (P < 0.001) with a specificity of 78% and sensitivity of 61%. PTT as an easily, even automatically obtainable and robust non-invasive biomarker of haemodynamics might help in the evaluation of patients with dyspnoea and HF.

Comparing Cardiac Mechanics and Myocardial Fibrosis in DBD and DCD Heart Transplant Recipients

BackgroundHeart transplantation (HTx) after donation after circulatory death (DCD) is an expanding practice but is associated with increased warm ischemic time. The impact of DCD HTx on cardiac mechanics and myocardial fibrosis has not been reported. We aimed to compare cardiac mechanics and myocardial fibrosis using cardiovascular magnetic resonance (CMR) imaging in donation after brain death (DBD) and DCD HTx recipients and healthy controls. Methods and ResultsConsecutive HTx recipients between March 2015 and March 2021 who underwent routine surveillance CMR imaging were included. Cardiac mechanics were assessed using CMR feature tracking to compute global longitudinal strain, global circumferential strain, and right ventricular free-wall longitudinal myocardial strain. Fibrosis was assessed using late gadolinium enhancement imaging and estimation of extracellular volume. There were 82 (DBD n = 42, DCD n = 40) HTx recipients (aged 53 years, interquartile range 41–59 years, 24% female) who underwent CMR imaging at median of 9 months (interquartile range 6–14 months) after transplantation. HTx recipients had increased extracellular volume (29.7 ± 3.6%) compared with normal ranges (25.9%, interquartile range 25.4–26.5). Myocardial strain was impaired after transplantation compared with controls (global longitudinal strain –12.6 ± 3.1% vs –17.2 ± 1.8%, P < .0001; global circumferential strain –16.9 ± 3.1% vs –19.2 ± 2.0%, P = .002; right ventricular free-wall longitudinal strain –15.7 ± 4.5% vs –21.6 ± 4.7%, P < .0001). There were no differences in fibrosis burden (extracellular volume 30.6 ± 4.4% vs 29.2 ± 3.2%; P = .39) or cardiac mechanics (global longitudinal strain –13.1 ± 3.0% vs –12.1 ± 3.1%, P = .14; global circumferential strain –17.3 ± 2.9% vs –16.6 ± 3.1%, P = .27; right ventricular free-wall longitudinal strain –15.9 ± 4.9% vs –15.5 ± 4.1%, P = .71) between DCD and DBD HTx. ConclusionsHTx recipients have impaired cardiac mechanics compared with controls, with increased myocardial fibrosis. There were no differences in early CMR imaging characteristics between DBD and DCD heart transplants, providing further evidence that DCD and DBD HTx outcomes are comparable.

Abstract 10933: Artificial Intelligence Enabled Fully Automated Myocardial Strain Quantification for Risk Stratification Following Acute Myocardial Infarction

Introduction: Feasibility of automated volume-derived cardiac functional evaluation has successfully been demonstrated using cardiovascular magnetic resonance (CMR) imaging. Notwithstanding, strain assessment has proven incremental value for cardiovascular risk stratification. Since introduction of deformation imaging to clinical practice has been complicated by time-consuming post-processing, we sought to investigate automation respectively. Methods: CMR data (n=1095 patients) from two prospectively recruited acute myocardial infarction (AMI) populations with ST-elevation (STEMI) (AIDA STEMI n=759) and non-STEMI (TATORT-NSTEMI n=336) were analysed fully automated and manually on conventional cine sequences. LV function assessment included global longitudinal, circumferential, and radial strains (GLS/GCS/GRS). Agreements were assessed between automated and manual strain assessments. The former were assessed for major adverse cardiac event (MACE) prediction within 12 months following AMI. Results: Manual and automated derived GLS showed the best and excellent agreement with an intraclass correlation coefficient (ICC) of 0.81. Agreement was good for GCS and poor for GRS. Amongst automated analyses, GLS (HR 1.12, 95% CI 1.08-1.16, p&lt;0.001) and GCS (HR 1.07, 95% CI 1.05-1.10, p&lt;0.001) best predicted MACE with similar diagnostic accuracy compared to manual analyses; area under the curve (AUC) for GLS (auto 0.691 vs. manual 0.693, p=0.801) and GCS (auto 0.668 vs. manual 0.686, p=0.425). Amongst automated functional analyses, GLS was the only independent predictor of MACE in multivariate analyses (HR 1.10, 95% CI 1.04-1.15, p&lt;0.001). Conclusions: Considering high agreement of automated GLS and equally high accuracy for risk prediction compared to the reference standard of manual analyses, automation may improve efficiency and aid in clinical routine CMR examinations.

Wearable Seismocardiography-Based Assessment of Stroke Volume in Congenital Heart Disease.

Background Patients with congenital heart disease (CHD) are at risk for the development of low cardiac output and other physiologic derangements, which could be detected early through continuous stroke volume (SV) measurement. Unfortunately, existing SV measurement methods are limited in the clinic because of their invasiveness (eg, thermodilution), location (eg, cardiac magnetic resonance imaging), or unreliability (eg, bioimpedance). Multimodal wearable sensing, leveraging the seismocardiogram, a sternal vibration signal associated with cardiomechanical activity, offers a means to monitoring SV conveniently, affordably, and continuously. However, it has not been evaluated in a population with significant anatomical and physiological differences (ie, children with CHD) or compared against a true gold standard (ie, cardiac magnetic resonance). Here, we present the feasibility of wearable estimation of SV in a diverse CHD population (N=45 patients). Methods and Results We used our chest-worn wearable biosensor to measure baseline ECG and seismocardiogram signals from patients with CHD before and after their routine cardiovascular magnetic resonance imaging, and derived features from the measured signals, predominantly systolic time intervals, to estimate SV using ridge regression. Wearable signal features achieved acceptable SV estimation (28% error with respect to cardiovascular magnetic resonance imaging) in a held-out test set, per cardiac output measurement guidelines, with a root-mean-square error of 11.48 mL and R2 of 0.76. Additionally, we observed that using a combination of electrical and cardiomechanical features surpassed the performance of either modality alone. Conclusions A convenient wearable biosensor that estimates SV enables remote monitoring of cardiac function and may potentially help identify decompensation in patients with CHD.

30-minute CMR for common clinical indications:\xa0a\xa0Society for Cardiovascular Magnetic Resonance white paper

BackgroundDespite decades of accruing evidence supporting the clinical utility of cardiovascular magnetic resonance (CMR), adoption of CMR in routine cardiovascular practice remains limited in many regions of the world. Persistent use of long scan times of 60 min or more contributes to limited adoption, though techniques available on most scanners afford routine CMR examination within 30 min. Incorporating such techniques into standardize protocols can answer common clinical questions in daily practice, including those related to heart failure, cardiomyopathy, ventricular arrhythmia, ischemic heart disease, and non-ischemic myocardial injury.BodyIn this white paper, we describe CMR protocols of 30 min or shorter duration with routine techniques with or without stress perfusion, plus specific approaches in patient and scanner room preparation for efficiency. Minimum requirements for the scanner gradient system, coil hardware and pulse sequences are detailed. Recent advances such as quantitative myocardial mapping and other add-on acquisitions can be incorporated into the proposed protocols without significant extension of scan duration for most patients.ConclusionCommon questions in clinical cardiovascular practice can be answered in routine CMR protocols under 30 min; their incorporation warrants consideration to facilitate increased access to CMR worldwide.

Major incidental findings on routine cardiovascular magnetic resonance imaging prior to first-time catheter ablation of atrial fibrillation.

IntroductionPreprocedural cardiovascular magnetic resonance (CMR) or computed tomography (CT) imaging of the left atrium/pulmonary veins is usually employed to guide catheter ablation of atrial fibrillation (AFCA). Incidental findings (IFs) are common on cardiac imaging prior to AFCA. However, previous studies have mainly focused on extracardiac IFs detected on CT scan. We aimed to assess the prevalence of relevant cardiac and extracardiac IFs on routine preprocedural CMR in a large patient cohort scheduled for first-time AFCA and report its impact on clinical decision-making and management.Methods and resultsWe included 2000 consecutive patients (62 ± 10 years; 59% male) who underwent CMR prior to first-time AFCA between April 2015 and March 2019. Among these patients 172 (8.6%) had a total of 184 major IFs. Detection of major IFs resulted in cancellation of the scheduled AFCA procedure in 88 patients (4.4%). Forty-two patients (2.1%) have never been ablated, 46 (2.3%) underwent postponed AFCA after a median time of 83 (32–213) days. The remaining 84 patients (4.2%) underwent an individualized approach to AFCA. The most common major IFs were accessory or anomalous PVs in 76 (3.8%), extracardiac abnormalities suspicious of malignancy in 29 (1.5%), and positive stress perfusion imaging in 19 (7.2% of 261 tested) patients. In 19 patients (1.0%) preprocedural CMR provided the diagnosis of a previously unknown structural cardiac disease.ConclusionsUnexpected relevant findings on routine preprocedural CMR affected clinical decision-making and management in 8.6% of patients scheduled for first-time AFCA. However, whether preprocedural CMR imaging may improve overall clinical outcome needs to be addressed in future research.

Real-time CMR guidance for intracardiac and great vessel pressure mapping in patients with congenital heart disease using an MR conditional guidewire-results of 25 patients.

The aim of this study was to test a CE-certified MR-conditional guidewire to facilitate blood pressure measurement in cardiovascular magnetic resonance (CMR) using fluid-filled catheters in patients with congenital heart disease (CHD). The main purpose was to determine procedural success in a post market clinical follow-up (PMCF) for routine procedure in a diagnostic and interventional workflow. Real-time CMR provides high quality imaging without the risk of exposing the patient to X-rays, especially for patients with irregular heart anatomy and patients who are susceptible to radiation and iodinated contrast media. To date, the assessment of blood pressure gradients is not a common feature of CMR, as these gradients cannot be accurately evaluated in routine CMR. Twenty-five CHD patients who were planned for combined clinical CMR and diagnostic and/or interventional catheterization were enrolled in the trial. Prior to inclusion, a specific procedure for catheterization in CMR was defined, encompassing the assessment of pressure and pressure gradients in the heart and great vessels. By the use of an MR-conditional guidewire we successfully measured specific pressure and pressure gradients in up to 92% of cases with liquid-filled catheters which were guided exclusively under CMR guidance. There were no guidewire-related adverse events, and guidewire guidance and manipulation of catheters were successful. Using a MR-conditional guidewire assists in easily reaching targets in the heart and great vessels and makes the catheter itself visible, so that invasive blood pressure assessment by CMR guidance with liquid-filled catheters can be improved. Cardiovascular magnetic resonance (CMR); congenital heart disease (CHD); cardiac catheterization; magnetic resonance; pressure; guidewire.

Liver magnetic resonance relaxometry can provide useful markers for the assessment of right heart failure in dilated cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Introduction In dilated cardiomyopathy (DCM) patients at risk of developing right heart failure (RHF), early depiction of congestive heart failure (CHF) is pivotal to inform about the hemodynamic status and tailor medical therapy. Purpose We hypothesized that increased liver relaxation times measured at routine cardiovascular magnetic resonance (CMR), reflecting passive hepatic congestion, may be a valuable imaging biomarker to depict CHF. Methods The study cohort included DCM patients with (n = 48) and without (n = 46) right ventricular dysfunction (RVD), defined as a right ventricular ejection fraction &amp;lt;35%, and &amp;gt;45%, respectively, and a control group (n = 40). Native T1, T2, and extracellular volume (ECV) liver values were measured on routinely acquired cardiac maps. Results DCM with RVD patients had higher C-reactive protein, troponin I and NT-pro BNP values, and worse LV functional parameters than DCM without RVD patients (all p &amp;lt; 0.001). T1, T2 and ECV liver values were significantly higher in DCM with, compared to DCM without, RVD patients and also compared to controls [T1: 675 ± 88ms vs. 538 ± 39ms and 540 ± 34ms; T2: 54 ± 8ms vs. 45 ± 5ms and 46 ± 4ms; ECV: 36 ± 7% vs. 29 ± 4% and 30 ± 3%, respectively (all p &amp;lt; 0.001)]. Gamma glutamyltranspeptidase (γGT) correlated moderately but significantly with liver native T1 (r2 =0.34), T2 (r2 =0.27), and ECV (r2 =0.23) (all p &amp;lt; 0.001). Using right atrial pressure (RAP &amp;gt; 5 mmHg), as a surrogate measure of RHF, liver native T1 yielded at ROC analysis the highest AUC (0.906), significantly higher than liver ECV (0.813), γGT (0.806), liver T2 (0.797), total bilirubin (0.737) and alkaline phosphatase (0.561) [Figure 1]. A liver native T1 value of 617 ms showed a sensitivity of 79.5% and a specificity of 91.0% in identifying RHF. Density plots to discriminate between presence and absence of RHF are demonstrated at Figure 2. Excellent intra-/inter-observer agreement was found for assessment of native T1/T2/ECV liver values. Conclusion In DCM patients, assessment of liver relaxation times acquired on a CMR exam, may provide valuable information with regard to the presence of RHF.

The Role of Cardiac Magnetic Resonance in Evaluation of Idiopathic Ventricular Arrhythmia in Children.

The aim of the study was to assess the role of cardiovascular magnetic resonance (CMR) in the diagnosis of idiopathic VA in children. This retrospective single-centre study included a total of 80 patients with idiopathic ventricular arrhythmia that underwent routine CMR imaging between 2016 and 2020 at our institution. All patients underwent a 3.0 T scan involving balanced steady-state free precession cine images as well as dark-blood T2W images and assessment of late gadolinium enhancement (LGE). In 26% of patients (n = 21) CMR revealed cardiac abnormalities, in 20% (n = 16) not suspected on prior echocardiography. The main findings included: non-ischemic ventricular scars (n = 8), arrhythmogenic right ventricular cardiomyopathy (n = 6), left ventricular clefts (n = 4) and active myocarditis (n = 3). LGE was present in 57% of patients with abnormal findings. Univariate predictors of abnormal CMR result included abnormalities in echocardiography and severe VA (combination of >10% of 24 h VA burden and/or presence of ventricular tachycardia and/or polymorphic VA). CMR provides valuable clinical information in many cases of idiopathic ventricular arrhythmia in children, mainly due to its advanced tissue characterization capabilities and potential to assess the right ventricle.

Assessment of Right-Sided Heart Failure in Patients with Dilated Cardiomyopathy using Magnetic Resonance Relaxometry of the Liver

In non-ischemic dilated cardiomyopathy (DC) patients at risk of developing right heart failure (RHF), early depiction of congestive heart failure (CHF) is pivotal to inform about the hemodynamic status and tailor medical therapy. We hypothesized increased liver relaxation times measured at routine cardiovascular magnetic resonance (CMR), reflecting passive hepatic congestion, may be a valuable imaging biomarker to depict congestive heart failure. The study cohort consisted of DC patients with LV dysfunction (i.e., ejection fraction <35%) with (n = 48) and without (n = 46) right ventricular dysfunction (RVD), defined as a right ventricular ejection fraction <35%, and >45%, respectively, and a control group (n = 40). Native T1, T2, and extracellular volume (ECV) liver values were measured on routinely acquired cardiac maps. DC+RVD patients had higher C-reactive protein, troponin I and NT-pro BNP values, and worse LV functional parameters than DC-RVD patients (all p <0.001). T1, T2 and ECV Liver values were significantly higher in DC+RVD compared to DC-RVD patients and controls, that is, T1: 675 ± 88 ms verses 538 ± 39 ms and 540 ± 34 ms; T2: 54± 8 ms versus 45 ± 5 ms and 46 ± 4 ms; ECV: 36 ± 7% versus 29 ± 4% and 30 ± 3% (all p <0.001). Gamma-glutamyltranspeptidase (GGT) correlated moderately but significantly with native T1 (r2 = 0.34), T2 (r2 = 0.27), and ECV liver (r2 = 0.23) (all p <0.001). Using right atrial (RA) pressure, as surrogate measure of RHF (i.e., RA pressure >5 mm Hg), native T1 liver yielded at ROC analysis the highest area under the curve (0.906), significantly higher than ECV liver (0.813), GGT (0.806), T2 liver (0.797), total bilirubin (0.737) and alkaline phosphatase (0.561)(p = 0.04). A T1 value of 617 ms yielded a sensitivity of 79.5% and specificity of 91.0% to depict RHF. Excellent intra-/inter-observer agreement was found for assessment of native T1/T2/ECV liver values. In conclusion, in DC patients, assessment of liver relaxation times acquired on a cardiovascular magnetic resonance exam, may provide valuable information with regard to the presence of RHF.

Quantification of regurgitation in mitral valve prolapse with four-dimensional flow cardiovascular magnetic resonance

BackgroundFour-dimensional cardiovascular magnetic resonance (CMR) flow assessment (4D flow) allows to derive volumetric quantitative parameters in mitral regurgitation (MR) using retrospective valve tracking. However, prior studies have been conducted in functional MR or in patients with congenital heart disease, thus, data regarding the usefulness of 4D flow CMR in case of a valve pathology like mitral valve prolapse (MVP) are scarce. This study aimed to evaluate the clinical utility of cine-guided valve segmentation of 4D flow CMR in assessment of MR in MVP when compared to standardized routine CMR and transthoracic echocardiography (TTE).MethodsSix healthy subjects and 54 patients (55 ± 16 years; 47 men) with MVP were studied. TTE severity grading used a multiparametric approach resulting in mild/mild-moderate (n = 12), moderate-severe (n = 12), and severe MR (n = 30). Regurgitant volume (RVol) and regurgitant fraction (RF) were also derived using standard volumetric CMR and 4D flow CMR datasets with direct measurement of regurgitant flow (4DFdirect) and indirect calculation using the formula: mitral valve forward flow - left ventricular outflow tract stroke volume (4DFindirect).ResultsThere was moderate to strong correlation between methods (r = 0.59–0.84, p < 0.001), but TTE proximal isovelocity surface area (PISA) method showed higher RVol as compared with CMR techniques (PISA vs. CMR, mean difference of 15.8 ml [95% CI 9.9–21.6]; PISA vs. 4DFindirect, 17.2 ml [8.4–25.9]; PISA vs. 4DFdirect, 27.9 ml [19.1–36.8]; p < 0.001). Only indirect CMR methods (CMR vs. 4DFindirect) showed moderate to substantial agreement (Lin’s coefficient 0.92–0.97) without significant bias (mean bias 1.05 ± 26 ml [− 50 to 52], p = 0.757). Intra- and inter-observer reliability were good to excellent for all methods (ICC 0.87–0.99), but with numerically lower coefficient of variation for indirect CMR methods (2.5 to 12%).ConclusionsIn the assessment of patients with MR and MVP, cine-guided valve segmentation 4D flow CMR is feasible and comparable to standard CMR, but with lower RVol when TTE is used as reference. 4DFindirect quantification has higher intra- and inter-technique agreement than 4DFdirect quantification and might be used as an adjunctive technique for cross-checking MR quantification in MVP.