Cardiovascular Magnetic Resonance Examination Research Articles

Effects of acute hydration changes on cardiovascular magnetic resonance native T1 and T2 mapping.

Changes in hydration status may affect myocardial native T1 and T2 values and influence the clinical interpretation. We aimed to assess the impact of acute preload augmentation on native T1 and T2. Cardiovascular magnetic resonance (CMR) native T1 and T2 mapping were performed twice on the same day in 20 healthy participants before and after an acute preload augmentation by a 2-liter intravenous infusion of isotonic sodium chloride (0.9%). Test-retest reproducibility was evaluated in 30 healthy participants with two consecutive CMR examinations on the same day. Sixteen participants were included in both substudies. In the 20 healthy participants undergoing acute preload augmentation (55% males, mean age (interquartile range [IQR]) 43 [29-51] years), native T1 increased with 17 ms (95% confidence interval [CI] 7 to 26; p = 0.001), T2 with 1.7 ms (95% CI 0.8 to 2.4; p < 0.001), and blood T1 with 46 ms (95% CI 28 to 65; p < 0.001). Test-retest variability in 30 healthy participants (47% males, median age 43 [28-52] years) showed 95% limits of agreement (LOA) of ± 26 ms for native T1, ± 2.1 ms for T2, and ± 57 ms for blood T1. In the 16 participants included in both substudies, the mean differences in changes post-infusion versus test-retest were 22 ms (95% CI 8 to 36; p = 0.01) for native T1, 1.9 ms (95% CI 0.9 to 2.9; p = 0.001) for T2, and 62 ms (95% CI 32 to 91; p < 0.001) for blood T1. Native T1 and T2 values increased following acute preload augmentation. However, the changes were within the 95% LOA of the test-retest reproducibility.

Association of prior tuberculosis with cardiovascular status in perinatally HIV-1-infected adolescents

BackgroundWhether, and how, co-occurring HIV-1 infection (HIV) and tuberculosis (TB) impact cardiovascular status, especially in adolescents with perinatally acquired HIV (APHIV), have not been examined. We hypothesised that APHIV with...

The neo-aortic valve in patients with hypoplastic left heart syndrome is largely preserved: a serial follow-up CMR study.

In hypoplastic left heart syndrome (HLHS) patients, neo-aortic valve regurgitation can negatively impact right ventricular (RV) function. We assessed neo-aortic valve function and RV volumetric parameters by analysing serial cardiovascular magnetic resonance (CMR) studies in HLHS patients after completion of total cavopulmonary connection (TCPC). Consecutive CMR examinations of 80 patients (female: 22) with two (n = 80) or three (n = 45) examinations each were retrospectively analysed. RV volumetry was performed using short-axis cine images. RV end-diastolic and end-systolic volumes normalised to body surface area (BSA, RVEDVi, RVESVi), ejection fraction (RVEF) and stroke volume (RVSV) were measured. Neo-aortic flow, regurgitant fraction (RF) and peak velocity were quantified from phase-contrast cine images. Median neo-aortic regurgitation was mild at all three examinations (RF <20%) and there was no significant increase in RF over time (p > 0.05). None of the patients had significant neo-aortic valve stenosis (peak velocity >3 m/s). RF correlated with RVESVi and RVEF at the second examination. At the third examination, RF correlated with RVESVi and RVEDVi even in patients with RF <15% (RVESVi: r = 0.40, p = 0.001; RVEDVi: r = 0.34, p = 0.031). Assessment of serial CMR studies in HLHS patients after TCPC completion demonstrates a preserved neo-aortic valve function. Nevertheless, thorough follow-up is mandatory as even mild neo-aortic dysfunction might impact RV size and function over a longer term.

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

Dynamic changes of excessive trabeculation in dilated cardiomyopathy: a longitudinal cardiovascular magnetic resonance study

Abstract Background A portion of dilated cardiomyopathy (DCM) patients present with left ventricular (LV) excessive trabeculation at diagnosis. It remains unknown if the extent of trabeculation would be reduced after guideline-directed medical therapy (GDMT). Purpose To investigate the dynamic change of excessive trabeculation after GDMT in patients with DCM, and its relationship with that in LV structure and function. Methods A group of DCM patients with baseline and follow-up cardiovascular magnetic resonance (CMR) examination after 1-2 years of GDMT were enrolled. Trabeculation was assessed by Petersen method as measuring the thickness of the most prominent non-compacted (NC) layer and the corresponding compacted (C) segment at the apical long-axis view at end-diastole. Excessive trabeculation was defined as the NC/C ratio &amp;gt; 2.3, and a regression was reached if it decreased to ≤ 2.3. Major adverse cardiovascular events (MACE) consisted of cardiovascular death, heart transplantation, and heart failure readmission. Results Among 218 DCM patients (45 ± 14 years, 67.4% male), 58 (26.6%) met the excessive trabeculation criteria at baseline. Despite a similar LV ejection fraction (LVEF), patients with excessive trabeculation had a higher LV end-diastolic dimension (73.3 ± 9.0 vs. 70.5 ± 8.0mm) and native T1 (1325.3 ± 71.2 vs. 1305.5 ± 65.9mm) (both p&amp;lt;0.05) with a trend of more late gadolinium enhancement (51.7% vs. 39.4% of patients). After 15 months of GDMT, patients with excessive trabeculation (n=58) showed a decreased NC layer (12.7 ± 3.4 vs. 11.3 ± 3.0 mm) and NC/C ratio (3.1 ± 0.9 vs. 2.7 ± 0.9) (both p &amp;lt; 0.05), 25.9% of whom showed a regression of trabeculation. Patients with the regression had a lower NC/C ratio (1.8 ± 0.4 vs. 3.0 ± 0.8, p &amp;lt; 0.001) and LV end-diastolic volume index (LVEDVi) (121.5 ± 40.5 ml/m2 vs. 165.9 ± 67.8ml/m2, p=0.004) compared with those without. The change of (△) NC/C ratio was associated with that of LVEDVi (r = 0.323), and LVEF as well (r = -0.254) (both p &amp;lt; 0.001). Excessive trabeculation at baseline did not differentiate patients with a higher risk of MACE by Kaplan-Meier survival curve (p= 0.208), but its persistent presence at follow-up did (p= 0.004). However, when put △NC/C ratio, △LVEDVi, △LVEF and In NT-proBNP into multivariate cox regression model, only the △LVEDVi (HR, 0.963; 95% CI: 0.942, 0.985; P = 0.001) and In NT-proBNP (HR, 2.016; 95% CI: 1.288, 3.157; P = 0.002) were independent predictors of MACE. Conclusions Regression of excessive trabeculation occurred after GDMT in DCM patients that was related somewhat to LV reverse remodeling and not an independent predictor of MACE. It may also indicate the interconnection between LV remodeling and trabeculation.

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.

Interventricular septum involvement is related to right ventricular dysfunction in anterior STEMI patients without right ventricular infarction: a cardiovascular magnetic resonance study.

The value of cardiovascular magnetic resonance (CMR) in assessing and predicting acute right ventricular (RV) dysfunction in patients with anterior ST-segment elevation myocardial infarction (STEMI) remains ascertained. Eightyeight patients with anterior STEMI were prospectively recruited and underwent CMR examinations within one week following the coronary intervention. Patients with RV ejection fraction (RVEF) less than 2 standard deviations below the average at the center (RVEF ≤ 45.0%) were defined as having RV dysfunction. The size of infarction, segmental wall motion, and T1 and T2 mapping values of global myocardium and the interventricular septum (IVS) were measured. Predictive performance was calculated using receiver-operating characteristic curve analysis and logistic regression test. Twentytwo patients presented with RV dysfunction. The RV dysfunction group had a larger IVS infarct extent (54.28 ± 10.35 vs 33.95 ± 15.09%, P < 0.001) and lower left ventricle stroke volume index (33.93 ± 7.96 vs 42.46 ± 8.14ml/m2, P < 0.001) compared to the non-RV dysfunction group. IVS infarct extent at 48.8% best predicted the presence of RV dysfunction with an area under the curve of 0.864. Left ventricular stroke volume index (LVSVI) and IVS infarct extent were selected by stepwise multivariable logistic regression analysis. LowerLVSVI (odds ratio [OR] 0.90; 95% confidence interval [CI], 0.79 to 0.99; P = 0.044) andhigher IVS infarct extent (OR 1.16; 95% CI 1.05 to 1.33; P = 0.01) were found to be independent predictors for RV dysfunction. In patients with anterior STEMI, those with larger IVS infarct extent and worse LV function are more likely to be associated with RV dysfunction.

Noninvasive Pressure-Volume Loops Predict Major Adverse Cardiac Events in Heart Failure With Reduced Ejection Fraction

BackgroundHeart failure with reduced ejection fraction (HFrEF) is characterized by ventricular remodeling and impaired myocardial energetics. Left ventricular pressure-volume (PV) loop analysis can be performed noninvasively using cardiovascular magnetic resonance (CMR) imaging to assess cardiac thermodynamic efficiency. ObjectivesThe aim of the study was to investigate whether noninvasive PV loop parameters, derived from CMR, could predict major adverse cardiac events (MACE) in HFrEF patients. MethodsPV loop parameters (stroke work, ventricular efficiency, external power, contractility, and energy per ejected volume) were computed from CMR cine images and brachial blood pressure. The primary endpoint was MACE (cardiovascular death, heart failure (HF) hospitalization, myocardial infarction, revascularization, ventricular tachycardia/fibrillation, heart transplantation, or left ventricular assist device implantation within 5 years). Associations between PV loop parameters and MACE were evaluated using multivariable Cox regression. ResultsA total of 164 HFrEF patients (left ventricular ejection fraction ≤40%, age 63 [IQR: 55-70] years, 79% male) who underwent clinical CMR examination between 2004 and 2014 were included. Eighty-eight patients (54%) experienced at least 1 MACE after an average of 2.8 years. Unadjusted models demonstrated a significant association between MACE and all PV loop parameters (P < 0.05 for all), HF etiology (P < 0.001), left ventricular ejection fraction (P = 0.003), global longitudinal strain (P < 0.001), and N-terminal prohormone of brain natriuretic peptide level (P = 0.001). In the multivariable Cox regression analysis adjusted for age, sex, hypertension, diabetes, and HF etiology, ventricular efficiency was associated with MACE (HR: 1.04, 95% CI: 1.01-1.08, per-% decrease, P = 0.01). ConclusionsVentricular efficiency, derived from noninvasive PV loop analysis from standard CMR scans, is associated with MACE in patients with HFrEF.

Assessing right ventricular peak strain in myocardial infarction patients with mitral regurgitation by cardiac magnetic resonance feature tracking.

Although it is known that mitral regurgitation (MR) in patients with myocardial infarction (MI) may increase the right ventricular (RV) afterload, leading to RV dysfunction, the exact detrimental effects on RV function and myocardial peak strain remain unresolved. In this study, we assessed the impact of MR on the impairment of RV myocardial deformation in patients with MI and explored the independent influential factors of RV peak strain. A total of 199 MI participants without or with MR were retrospectively assessed in this study. The cardiovascular magnetic resonance examination protocol included a late gadolinium-enhanced (LGE) imaging technique and a cine-balanced steady-state free precession sequence. Statistical tests, including two independent sample t-test or Mann-Whitney U-test, analysis of variance, Kruskal-Wallis test, and multiple linear regression analysis models were performed. The MI (MR+) group exhibited significantly lower RV strain parameters in the radial, circumferential and longitudinal directions when compared to the control and the MI (MR-) groups (both P<0.05). The RV global longitudinal peak strain (GLPS) in the MI group significantly decreased when compared with that in the control group (P<0.05). As moderate-severe MR worsened in patients with MI, RV myocardial global peak strain and the peak systolic strain rate (PSSR) gradually decreased. Multiple linear regression analysis revealed that left ventricular (LV) GLPS, triglycerides, and age were independently correlated with RV GLPS (all P<0.05). RV end-systolic volume (RVESV) acted as an independent association factor for RV global peak strain. MR may exacerbate the impairment of RV peak strain and functions in patients with MI. LV GLPS was positively correlated with RV GLPS. However, RVESV, triglycerides, and age acted as independent risk factors associated with worsening RV GLPS.

Cine-cardiac magnetic resonance to distinguish between ischemic and non-ischemic cardiomyopathies: a machine learning approach

ObjectiveThis work aimed to derive a machine learning (ML) model for the differentiation between ischemic cardiomyopathy (ICM) and non-ischemic cardiomyopathy (NICM) on non-contrast cardiovascular magnetic resonance (CMR).MethodsThis retrospective study evaluated CMR scans of 107 consecutive patients (49 ICM, 58 NICM), including atrial and ventricular strain parameters. We used these data to compare an explainable tree-based gradient boosting additive model with four traditional ML models for the differentiation of ICM and NICM. The models were trained and internally validated with repeated cross-validation according to discrimination and calibration. Furthermore, we examined important variables for distinguishing between ICM and NICM.ResultsA total of 107 patients and 38 variables were available for the analysis. Of those, 49 were ICM (34 males, mean age 60 ± 9 years) and 58 patients were NICM (38 males, mean age 56 ± 19 years). After 10 repetitions of the tenfold cross-validation, the proposed model achieved the highest area under curve (0.82, 95% CI [0.47–1.00]) and lowest Brier score (0.19, 95% CI [0.13–0.27]), showing competitive diagnostic accuracy and calibration. At the Youden’s index, sensitivity was 0.72 (95% CI [0.68–0.76]), the highest of all. Analysis of predictions revealed that both atrial and ventricular strain CMR parameters were important for the identification of ICM patients.ConclusionThe current study demonstrated that using a ML model, multi chamber myocardial strain, and function on non-contrast CMR parameters enables the discrimination between ICM and NICM with competitive diagnostic accuracy.Clinical relevance statementA machine learning model based on non-contrast cardiovascular magnetic resonance parameters may discriminate between ischemic and non-ischemic cardiomyopathy enabling wider access to cardiovascular magnetic resonance examinations with lower costs and faster imaging acquisition.Key Points• The exponential growth in cardiovascular magnetic resonance examinations may require faster and more cost-effective protocols.• Artificial intelligence models can be utilized to distinguish between ischemic and non-ischemic etiologies.• Machine learning using non-contrast CMR parameters can effectively distinguish between ischemic and non-ischemic cardiomyopathies.Graphical

Awareness of strengths and weaknesses of cardiovascular magnetic resonance imaging: results from a questionnaire survey.

Extensive research has established cardiovascular magnetic resonance (CMR) as a powerful tool for diagnosing and monitoring various cardiovascular diseases (CVDs). However, CMR has yet to reach its full potential in routine clinical care, which is mainly due to reimbursement issues. Among other factors, overcoming this gap requires adequate awareness among healthcare professionals and potential patients, the extent of which is currently unknown. Therefore, we conducted a survey to assess awareness and identify knowledge gaps regarding the clinical role and socio-economic factors associated with CMR. One hundred forty-four subjects not involved in direct patient care were enrolled at a German health conference and completed a 24-item survey, including procedural, clinical, and socio-economic questions about CMR. Respondents were well aware of the socio-economic impact of CVD. Common CMR indications were correctly identified by most participants, but only 22.9% knew the full spectrum. Participants underestimated the modality's benefits, such as absence of ionizing radiation and rare allergic reactions to contrast agents (only 70.9% and 37.6% correct answers, respectively). Respondents estimated the therapeutic guidance of CMR to be high (50.7% voted impact > 50%) and the annual demand to be increasing (89.9%). Attitudes towards CMR were generally positive, with 77.1% of participants willing to travel >25 km and 60.4% willing to pay >125 Euros to have a CMR examination. Despite great interest in CMR, significant knowledge gaps hinder its optimal use in clinical practice. The development and implementation of awareness and education strategies are needed to realize the full clinical potential of CMR.

CMR characterization of patients with heart failure and left bundle branch block

Abstract Aims We aimed to identify the distinctive cardiovascular magnetic resonance (CMR) features of patients with left bundle branch block (LBBB) and heart failure with reduced ejection fraction (HFrEF) of presumed non-ischaemic aetiology. The secondary aim was to determine whether these individuals exhibit characteristics that could potentially serve as predictors of left ventricular ejection fraction (LVEF) recovery as compared with patients without LBBB. Methods and results We prospectively recruited patients with HFrEF (LVEF ≤ 40%) on echocardiography who were referred for early CMR examination. Patients with an established diagnosis of coronary artery disease and known structural or congenital heart disease were excluded. LV recovery was defined as achieving ≥10% absolute improvement to ≥40% in LVEF between baseline evaluation to CMR. A total of 391 patients were recruited including 115 (29.4%) with LBBB. Compared with HF patients without LBBB, those with LBBB exhibited larger left ventricles and smaller right ventricles, but no differences were observed with respect to LVEF (35.8 ± 12 vs. 38 ± 12%, P = 0.105). The overall rate of LV recovery from baseline echocardiogram to CMR (70 [42–128] days) was not significantly different between LBBB and non-LBBB patients (27.8% vs. 31.5%, P = 0.47). Reduced LVEF remained an independent predictor of LV non-recovery only in patients with LBBB. Conclusion Patients presenting with HFrEF and LBBB had larger LV cavities and smaller RV cavities than those without LBBB but no difference in prevalence of scar or ischaemia. The rates of LV recovery were similar between both groups, which supports current guidelines to defer device therapy until 3–6 months of guideline-directed medical therapy, rather than early CMR and device implantation.

Characterization and z-score calculation of cardiovascular magnetic resonance imaging parameters in patients after the Fontan operation: A Fontan Outcome Registry using Cardiovascular Magnetic Resonance Examinations study

BackgroundCardiac magnetic resonance (CMR) offers valuable hemodynamic insights post-Fontan, but is limited by the absence of normative single ventricle data. The Fontan Outcomes Registry using CMR Examinations (FORCE) is a large international Fontan-specific CMR registry. This study used FORCE registry data to evaluate expected CMR ventricular size/function and create Fontan-specific z-scores adjusting for ventricular morphology (VM) in healthier Fontan patients. Methods“Healthier” Fontan patients were defined as patients free of adverse outcomes, who are New York Heart Association Class I, have mild or less valve disease, and <30% aortopulmonary collateral burden. General linear modeling was performed on 70% of the dataset to create z-scores for volumes and function. Models were tested using the remainder (30%) of the data. The z-scores were compared between children and adults. The z-scores were also compared between “healthier” Fontan and patients with adverse outcomes (death, listing for transplantation or multiorgan disease). ResultsThe “healthier” Fontan population included 885 patients (15.0 ± 7.6 years) from 18 institutions with 1,156 CMR examinations. Patients with left ventricle morphology had lower volume, mass and higher ejection fraction (EF) compared to right or mixed (two-ventricles) morphology (p<0.001 for all pairwise comparisons). Gender, BSA and VM were used in z-scores. Of the “healthier” Fontan patients, 647 were children <18 years and 238 were adults. Adults had lower ascending aorta flow (2.9 ± 0.7 vs 3.3 ± 0.8L/min/m2, p<0.001) and ascending aorta flow z-scores (-0.16 ± 1.23 vs 0.05 ± 0.95, 0.02) compared to children. Additionally, there were 1595 patients with adverse outcomes who were older (16.1 ± 9.3 vs 15.0 ± 7.6, p<0.001) and less likely to have LV morphology (35 vs 47%, p<0.001). Patients with adverse outcomes had higher z-scores for ventricular volume and mass and lower z-scores for EF and ascending aorta flow compared to the “healthier” Fontan cohort. ConclusionThis is the first study to generate CMR z-scores post-Fontan. Importantly the z-scores were generated and tested in “healthier” Fontan patients and both pediatric and adult Fontan patients. These equations may improve CMR-based risk stratification after the Fontan operation.

Society for Cardiovascular Magnetic Resonance guidelines for reporting cardiovascular magnetic resonance examinations in patients with congenital heart disease

Society for Cardiovascular Magnetic Resonance guidelines for reporting cardiovascular magnetic resonance examinations in patients with congenital heart disease

The influence of post-processing software on quantitative results in 4D flow cardiovascular magnetic resonance examinations.

Several commercially available software packages exist for the analysis of three-dimensional cine phase-contrast cardiovascular magnetic resonance (CMR) with three-directional velocity encoding (four-dimensional (4D) flow CMR). Only sparse data are available on the impact of these different software solutions on quantitative results. We compared two different commercially available and widely used software packages and their impact on the forward flow volume (FFV), peak velocity (PV), and maximum wall shear stress (WSS) per plane. 4D flow CMR datasets acquired by 3 Tesla magnetic resonance imaging of 10 healthy volunteers, 13 aortic stenosis patients, and 7 aortic valve replacement patients were retrospectively analyzed for FFV, PV, and WSS using two software packages in six analysis planes along the thoracic aorta. Absolute (AD) and relative differences (RD), intraclass correlation coefficients (ICC), Bland-Altman analysis, and Spearman's correlation analysis were calculated. For the FFV and PV in healthy volunteers, there was good to excellent agreement between both software packages [FFV: ICC = 0.93-0.97, AD: 0.1 ± 5.4 ml (-2.3 ± 2.4 ml), RD: -0.3 ± 8% (-5.7 ± 6.0%); PV: ICC = 0.81-0.99, AD: -0.02 ± 0.02 ml (-0.1 ± 0.1 ml), RD: -1.6 ± 2.1% (-9.3 ± 6.1%)]. In patients, the FFV showed good to excellent agreement [ICC: 0.75-0.91, AD: -1.8 ± 6.5 ml (-8.3 ± 9.9 ml), RD: -2.2 ± 9.2% (-13.8 ± 17.4%)]. In the ascending aorta, PV showed only poor to moderate agreement in patients (plane 2 ICC: 0.33, plane 3 ICC: 0.72), whereas the rest of the thoracic aorta revealed good to excellent agreement [ICC: 0.95-0.98, AD: -0.03 ± 0.07 (-0.1 ± 0.1 m/s), RD: -3.5 ± 7.9% (-7.8 ± 9.9%)]. WSS analysis showed no to poor agreement between both software packages. Global correlation analyses revealed good to very good correlation between FFV and PV and only poor correlation for WSS. There was good to very good agreement for the FFV and PV except for the ascending aorta in patients when comparing PV and no agreement for WSS. Standardization is therefore necessary.

Cardiac MR Fingerprinting: Overview, Technical Developments, and Applications.

Cardiovascular magnetic resonance (CMR) is an established imaging modality with proven utility in assessing cardiovascular diseases. The ability of CMR to characterize myocardial tissue using T1- and T2-weighted imaging, parametric mapping, and late gadolinium enhancement has allowed for the non-invasive identification of specific pathologies not previously possible with modalities like echocardiography. However, CMR examinations are lengthy and technically complex, requiring multiple pulse sequences and different anatomical planes to comprehensively assess myocardial structure, function, and tissue composition. To increase the overall impact of this modality, there is a need to simplify and shorten CMR exams to improve access and efficiency, while also providing reproducible quantitative measurements. Multiparametric MRI techniques that measure multiple tissue properties offer one potential solution to this problem. This review provides an in-depth look at one such multiparametric approach, cardiac magnetic resonance fingerprinting (MRF). The article is structured as follows. First, a brief review of single-parametric and (non-Fingerprinting) multiparametric CMR mapping techniques is presented. Second, a general overview of cardiac MRF is provided covering pulse sequence implementation, dictionary generation, fast k-space sampling methods, and pattern recognition. Third, recent technical advances in cardiac MRF are covered spanning a variety of topics, including simultaneous multislice and 3D sampling, motion correction algorithms, cine MRF, synthetic multicontrast imaging, extensions to measure additional clinically important tissue properties (proton density fat fraction, T2*, and T1ρ), and deep learning methods for image reconstruction and parameter estimation. The last section will discuss potential clinical applications, concluding with a perspective on how multiparametric techniques like MRF may enable streamlined CMR protocols. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 1.

Prognostic Significance of Biventricular and Biatrial Strain in Dilated Cardiomyopathy: Strain Analysis Derived from Cardiovascular Magnetic Resonance.

Dilated cardiomyopathy (DCM) has a poor prognosis and high mortality. The relationship between the deformation capacity of the biatrial and biventricular regions in patients with DCM remains unclear. This retrospective study used cardiovascular magnetic resonance (CMR) to assess patient enrollment between September 2020 to May 2022. Feature tracking (FT) was used to evaluate biventricular global radial strain (GRS), global circumferential strain (GCS) and global longitudinal strain (GLS). Fast long-axis method was used to evaluate biatrial GLS by analyzing balanced steady-state free precession cine images. The median follow-up period was 362 days (interquartile range: 234 to 500 days). DCM patients were divided into two groups based on the occurrence or non-occurrence of major adverse cardiac event (MACE). The primary endpoint was defined as all-cause death, heart transplantation, and adverse ventricular arrhythmia. The secondary end point included hospitalizations due to heart failure. Cox regression analysis was utilized for variables and Kaplan-Meier survival was utilized for clinical outcomes. There were 124 DCM patients (52.82 12.59 years, 67.74% male) and 53 healthy volunteers (53.17 14.67 years, 52.83% male) recruited in this study. Biventricular GRS, GCS, GLS, and biatrial GLS were significantly impaired in the DCM group compared with the healthy group. In receiver-operating characteristic curve, biatrial GLS and biventricular GRS, GCS, and GLS showed significant prognostic value in predicting MACEs (all p 0.05). In multivariate Cox regression analysis, left ventricular (LV) GLS offered a significant and independent prognostic value surpassing other CMR parameters in predicting MACE. In Kaplan-Meier analysis, patients with a LV GLS -4.81% had a significantly higher rate of MACE (Log-rank p 0.001). LV GLS was independently associated with MACEs in DCM patients by using FT and fast long-axis method derived from CMR. Comprehensive CMR examination including biatrial and biventricular functions should be systematically performed, to understand disease characteristics, as well as improve the risk stratification and therapeutic management for patients with DCM.

Two-center validation of Pilot Tone based cardiac triggering of a comprehensive cardiovascular magnetic resonance examination.

The electrocardiogram (ECG) signal is prone to distortions from gradient and radiofrequency interference and the magnetohydrodynamic effect during cardiovascular magnetic resonance imaging (CMR). Although Pilot Tone Cardiac (PTC) triggering has the potential to overcome these limitations, effectiveness across various CMR techniques has yet to be established. To evaluate the performance of PTC triggering in a comprehensive CMR exam. Fifteen volunteers and 20 patients were recruited at two centers. ECG triggered images were collected for comparison in a subset of sequences. The PTC trigger accuracy was evaluated against ECG in cine acquisitions. Two experienced readers scored image quality in PTC-triggered cine, late gadolinium enhancement (LGE), and T1- and T2-weighted dark-blood turbo spin echo (DB-TSE) images. Quantitative cardiac function, flow, and parametric mapping values obtained using PTC and ECG triggered sequences were compared. Breath-held segmented cine used for trigger timing analysis was collected in 15 volunteers and 14 patients. PTC calibration failed in three volunteers and one patient; ECG trigger recording failed in one patient. Out of 1987 total heartbeats, three mismatched trigger PTC-ECG pairs were found. Image quality scores showed no significant difference between PTC and ECG triggering. There was no significant difference found in quantitative measurements in volunteers. In patients, the only significant difference was found in post-contrast T1 (p = 0.04). ICC showed moderate to excellent agreement in all measurements. PTC performance was equivalent to ECG in terms of triggering consistency, image quality, and quantitative image measurements across multiple CMR applications.

Non-invasive pressure volume loops derived by cardiovascular magnetic resonance: association between area at risk or infarct size and cardiac hemodynamics at 2-6 days after myocardial infarction

Abstract Background A novel non-invasive method for generation of pressure volume loops (PV-loops) using brachial blood pressure and cardiovascular magnetic resonance (CMR) imaging has recently been presented and validated (1). The non-invasive nature of this method enables calculation of PV-loops in large patient cohorts previously not feasible due to the need of invasive measurements. Purpose The purpose of the present study was to investigate how cardiac hemodynamics assessed by PV-loop variables such as stroke work, potential energy, contractility and ventriculoarterial coupling is related to myocardium at risk and infarct size in a cohort of patients with acute myocardial infarction (MI). Method A total of 100 patients with ST-elevation MI (STEMI) were included from the SOCCER, MITOCARE and CHILL-MI trials (2-4). The CHILL-MI cohort (n = 11) was prone to a stricter selection criterion than the SOCCER cohort, including first-time myocardial infarction and no comorbidities. All patients underwent a CMR examination at 2-6 days after MI. Non-invasive PV-loops were generated by combining volumetric CMR data and brachial sphygmomanometric pressure measurements using a recently validated method (1). Maximal elastance (Emax, translated to contractility), stroke work, potential energy and ventriculoarterial coupling (Ea/Emax) were measured from the PV-loops. Myocardium at risk and infarct size were assessed using contrast-enhanced steady state free precession and late gadolinium enhancement images, respectively. Results Contractility, ventriculoarterial coupling, stroke work and potential energy all correlated to myocardium at risk (Emax: r²=0.25, Ea/Emax: r²=0.36, stroke work: r²=0.21, potential energy: r²=0.10) and infarct size (Emax: r²=0.29, Ea/Emax: r²=0.41, stroke work: r²=0.25, potential energy: r²=0.15) as shown in Figure 1. Furthermore, contractility showed a stronger correlation to myocardium at risk (Emax: r²=0.77) than to infarct size (Emax: r²=0.37) for the CHILL-MI patients as shown in Figure 2. Conclusion Non-invasive CMR derived PV-loop parameters can be used to assess cardiac hemodynamics early after STEMI showing that increased myocardium at risk and infarct size are both associated with an increased ventriculoarterial coupling and potential energy, and a decreased contractility and stroke work. To what extent these hemodynamic parameters provide incremental prognostic information compared to conventional parameters such as ejection fraction and left ventricular dimensions after STEMI remains to be determined.Figure 1Figure 2

Non-invasive pressure-volume loops from cardiovascular magnetic resonance predict cardiovascular mortality in heart failure with reduced ejection fraction

Abstract Background Heart failure with reduced ejection fraction (HFrEF) is characterized by impaired ventricular energetics secondary to ventricular remodeling. Left ventricular pressure-volume (PV) loop analysis (Figure 1) can now be performed noninvasively using cardiovascular magnetic resonance (CMR) imaging, enabling study of cardiac thermodynamic efficiency without the risk and cost associated with invasive measurements (1–3). Here we investigated whether noninvasive PV loops from CMR can predict cardiovascular death in HFrEF patients. Methods We analyzed 135 datasets (age 60±12 years, 79% male) from HFrEF patients (LVEF≤40%) who underwent clinical CMR examination at our center between 2004-2013. Pressure-volume loop parameters were computed from manually segmented CMR data and same-day brachial blood pressure (Segment 4.0 R11026, Medviso, Lund, Sweden). The primary endpoint was cardiovascular mortality extracted from national registries with a 5-year follow-up. Parameters of interest were selected from univariate Cox regression, and associations with clinical outcome evaluated using multivariate Cox regression. Survival was visualized using Kaplan-Meier analysis. Statistical analysis was performed in R 4.0.3 (R Core Team). Results A total of 19 deaths from cardiovascular causes occurred during follow-up. Univariate Cox regression found stroke work (SW, joule), ventricular efficiency (VE, %), external power (J/s), contractility (mmHg/ml), and energy per ejected volume (mJ/ml) computed from PV loops associated with the primary endpoint alongside age, LVEF, and NT-proBNP level. In multivariate Cox regression adjusted for age, ventricular efficiency remained significant (HR 0.86, p&amp;lt;0.001), while EF did not (p = 0.077). Event-free survival is shown in Figure 2. Conclusion Ventricular efficiency derived from non-invasive pressure-volume loop analysis from standard CMR scans, may outperform LV EF as a predictor of cardiovascular mortality in HFrEF. Figures: Figure 1. Example of left ventricular pressure-volume (PV) loop. The area enclosed by the loop is the stroke work (SW). The area bounded by the PV loop and the end-systolic pressure-volume relationship (ESPVR) is the potential energy (PE). Ventricular efficiency (VE) is calculated as SW/(PE+SW). Figure 2. Kaplan-Meier plots of survival by tertiles of stroke work and ventricular efficiency.Figure 1Figure 2