Multivendor comparison of global and regional 2D cardiovascular magnetic resonance feature tracking strains vs tissue tagging at 3T.

BACKGROUND: Cardiovascular magnetic resonance (CMR) 2D feature tracking (FT) left ventricular (LV) myocardial strain has seen widespread use to characterize myocardial deformation. Yet, validation of CMR FT measurements remains scarce, particularly for regional strain. Therefore, we aimed to perform intervendor comparison of 3 different FT software against tagging. METHODS: In 61 subjects (18 healthy subjects, 18 patients with chronic myocardial infarction, 15 with dilated cardiomyopathy, and 10 with LV hypertrophy due to hypertrophic cardiomyopathy or aortic stenosis) were prospectively compared global (G) and regional transmural peak-systolic Lagrangian longitudinal (LS), circumferential (CS) and radial strains (RS) by 3 FT software (cvi42, Segment, and Tomtec) among each other and with tagging at 3T. We also evaluated the ability of regional LS, CS, and RS by different FT software vs tagging to identify late gadolinium enhancement (LGE) in the 18 infarct patients. RESULTS: GLS and GCS by all 3 software had an excellent agreement among each other (ICC = 0.94-0.98 for GLS and ICC = 0.96-0.98 for GCS respectively) and against tagging (ICC = 0.92-0.94 for GLS and ICC = 0.88-0.91 for GCS respectively), while GRS showed inconsistent agreement between vendors (ICC 0.10-0.81). For regional LS, the agreement was good (ICC = 0.68) between 2 vendors but less vs the 3rd (ICC 0.50-0.59) and moderate to poor (ICC 0.44-0.47) between all three FT software and tagging. Also, for regional CS agreement between 2 software was higher (ICC = 0.80) than against the 3rd (ICC = 0.58-0.60), and both better agreed with tagging (ICC = 0.70-0.72) than the 3rd (ICC = 0.57). Regional RS had more variation in the agreement between methods ranging from good (ICC = 0.75) to poor (ICC = 0.05). Finally, the accuracy of scar detection by regional strains differed among the 3 FT software. While the accuracy of regional LS was similar, CS by one software was less accurate (AUC 0.68) than tagging (AUC 0.80, p < 0.006) and RS less accurate (AUC 0.578) than the other two (AUC 0.76 and 0.73, p < 0.02) to discriminate segments with LGE. CONCLUSIONS: We confirm good agreement of CMR FT and little intervendor difference for GLS and GCS evaluation, with variable agreement for GRS. For regional strain evaluation, intervendor difference was larger, especially for RS, and the diagnostic performance varied more substantially among different vendors for regional strain analysis.

Meta-Analysis of the Prognostic Role of Late Gadolinium Enhancement and Global Systolic Impairment in Left Ventricular Noncompaction.

OBJECTIVES: The objective of this meta-analysis was to assess the predictive value of late gadolinium enhancement (LGE) and global systolic impairment for future major adverse cardiovascular events in left ventricular noncompaction (LVNC). BACKGROUND: The prognosis of patients with LVNC, with and without left ventricular dysfunction and LGE, is still unclear. METHODS: A systematic review of published research and a meta-analysis reporting a combined endpoint of hard (cardiac death, sudden cardiac death, appropriate defibrillator firing, resuscitated cardiac arrest, cardiac transplantation, assist device implantation) and minor (heart failure hospitalization and thromboembolic events) events was performed. RESULTS: Four studies with 574 patients with LVNC and 677 with no LVNC and an average follow-up duration of 5.2 years were analyzed. In patients with LVNC, LGE was associated with the combined endpoint (pooled odds ratio: 4.9; 95% confidence interval: 1.63 to 14.6; p = 0.005) and cardiac death (pooled odds ratio: 9.8; 95% confidence interval: 2.44 to 39.5; p < 0.001). Preserved left ventricular systolic function was found in 183 patients with LVNC: 25 with positive LGE and 158 with negative LGE. In LVNC with preserved ejection fraction, positive LGE was associated with hard cardiac events (odds ratio: 6.1; 95% confidence interval: 2.1 to 17.5; p < 0.001). No hard cardiac events were recorded in patients with LVNC, preserved ejection fraction, and negative LGE. CONCLUSIONS: Patients with LVNC but without LGE have a better prognosis than those with LGE. When LGE is negative and global systolic function is preserved, no hard cardiac events are to be expected. Currently available criteria allow diagnosis of LVNC, but to further define the presence and prognostic significance of the disease, LGE and/or global systolic impairment must be considered for better risk stratification.

Additional Prognostic Value of 2D Right Ventricular Speckle-Tracking Strain for Prediction of Survival in Heart Failure and Reduced Ejection Fraction: A Comparative Study With Cardiac Magnetic Resonance.

OBJECTIVES: This study sought to compare the prognostic value of 2-dimensional (2D) right ventricular (RV) speckle tracking (STE) against cardiac magnetic resonance (CMR) RV ejection fraction (EF) and feature tracking (FT) and conventional echocardiographic parameters on overall and cardiovascular (CV) survival in patients with heart failure with reduced EF (HFrEF). BACKGROUND: Prior works showed that RV systolic function predicts prognosis in HFrEF. 2D RVSTE had recently been proposed as new echocardiographic method to evaluate RV dysfunction. METHODS: A total of 266 patients with HFrEF (mean LVEF 23 ± 7%, 60 ± 14 years of age; 29% women) underwent RV function assessment using CMR and 2D echocardiography and were followed for a primary endpoint of overall death and secondary endpoint of CV death. RESULTS: Average CMR-RVEF was 42 ± 15%, average STE RV global longitudinal strain (STE-RVGLS) was -18.0 ± 4.9%, and average CMR-FT-RVGLS was -11.8 ± 4.3%. After a median follow-up of 4.7 years, 102 patients died, 84 of a CV cause. RVEF, FT-RVGLS, tricuspid annulus plane systolic excursion (TAPSE), fractional area change (FAC), and STE-RVGLS were significant univariate predictors of overall and cardiac death. In multivariate Cox regression, age, ischemic etiology, diabetes, New York Heart Association functional class III to IV, and beta-blocker treatment were independent clinical predictors of overall mortality. CMR-RVEF (chi-square to enter = 3.9; p < 0.05), FT-RVGLS (chi-square to enter 3.7; p = 0.05), FAC (chi-square to enter 6.2; p = 0.02), and TAPSE (chi-square to enter = 4.1; p = 0.04) provided additional prognostic value over these baseline parameters, but the additional predictive value of STE-RVGLS (chi-square to enter = 10.8; p < 0.001) was significantly (p < 0.05) higher than the other tests. Additional hazard ratio to predict overall mortality was 2.5 (95% confidence interval [CI]: 1.6 to 3.9) for STE-RVGLS <-19%, 2.15 (95% CI: 1.34 to 3.43) for TAPSE >15 mm, 1.6 (95% CI: 1.02 to 2.49) for FAC >39%, 1.93 (95% CI: 1.25 to 2.99) for RVEF >41%, and 1.87 (95% CI: 1.10 to 3.19) for CMR-FT-RVGLS <-15%. CONCLUSIONS: 2D RVGLS provides strong additional prognostic value to predict overall and CV mortality in HFrEF, with higher predictive value than CMR-RVEF, CMR-FT-RVGLS, TAPSE, or FAC. This supports use of STE-RVGLS to identify higher-risk HFrEF patients.

Regional Multi-View Learning for Cardiac Motion Analysis: Application to Identification of Dilated Cardiomyopathy Patients.

OBJECTIVE: The aim of this paper is to describe an automated diagnostic pipeline that uses as input only ultrasound (US) data, but is at the same time informed by a training database of multimodal magnetic resonance (MR) and US image data. METHODS: We create a multimodal cardiac motion atlas from three-dimensional (3-D) MR and 3-D US data followed by multi-view machine learning algorithms to combine and extract the most meaningful cardiac descriptors for classification of dilated cardiomyopathy (DCM) patients using US data only. More specifically, we propose two algorithms based on multi-view linear discriminant analysis and multi-view Laplacian support vector machines (MvLapSVMs). Furthermore, a novel regional multi-view approach is proposed to exploit the regional relationships between the two modalities. RESULTS: We evaluate our pipeline on the classification task of discriminating between normals and DCM patients. Results show that the use of multi-view classifiers together with a cardiac motion atlas results in a statistically significant improvement in accuracy compared to classification without the multimodal atlas. MvLapSVM was able to achieve the highest accuracy for both the global approach (92.71%) and the regional approach (94.32%). CONCLUSION: Our work represents an important contribution to the understanding of cardiac motion, which is an important aid in the quantification of the contractility and function of the left ventricular myocardium. SIGNIFICANCE: The intended workflow of the developed pipeline is to make use of the prior knowledge from the multimodal atlas to enable robust extraction of indicators from 3-D US images for detecting DCM patients.

Head-to-Head Comparison of Global and Regional Two-Dimensional Speckle Tracking Strain Versus Cardiac Magnetic Resonance Tagging in a Multicenter Validation Study.

BACKGROUND: Despite widespread use to characterize and refine prognosis, validation data of two-dimensional (2D) speckle tracking (2DST) echocardiography myocardial strain measurement remain scarce. METHODS AND RESULTS: Global and regional subendocardial peak-systolic Lagrangian longitudinal (LS) and circumferential strain (CS) by 2DST and 2D-tagged (2DTagg) cardiac magnetic resonance imaging were compared against sonomicrometry in a dynamic heart phantom and among each other in 136 patients included prospectively at 2 centers. The ability of regional LS and CS 2DST and 2DTagg to identify late gadolinium enhancement was compared using receiver operating characteristics curves. In vitro, both LS-2DST and 2DTagg highly agreed with sonomicrometry (intraclass correlation coefficient [ICC], 0.89 and ICC, 0.90, both P<0.001 with -3±2.8% and 0.34±4.35% bias, respectively). In patients, both global LS and global CS 2DST agreed well with 2DTagg (ICC, 0.89 and ICC, 0.80; P<0.001); however, they provided systematically greater values (relative bias of -37±27% and -25±37% for global LS and global CS, respectively). On regional basis, however, ICC (from 0.17 to 0.81) and relative bias (from -9 to -98%) between 2DST and 2DTagg varied strongly among segments. Ability to discriminate infarcted versus noninfarcted segments by late gadolinium enhancement was similarly good for regional LS 2DTagg and 2DST (area under the curve, 0.66 versus 0.59; P=0.08), while it was lower for CS 2DST than 2DTagg (area under the curve, 0.61 versus 0.75; P<0.001). CONCLUSIONS: The high accuracy against sonomicrometry and good agreement of global LS and global CS by 2DST and 2DTagg confirm the overall validity of 2DST strain measurement. Yet, higher intertechnique segmental variability and lower ability for detecting infarct suggest that 2DST strain estimates may be less performant on regional than on global basis.

A multimodal spatiotemporal cardiac motion atlas from MR and ultrasound data.

Cardiac motion atlases provide a space of reference in which the motions of a cohort of subjects can be directly compared. Motion atlases can be used to learn descriptors that are linked to different pathologies and which can subsequently be used for diagnosis. To date, all such atlases have been formed and applied using data from the same modality. In this work we propose a framework to build a multimodal cardiac motion atlas from 3D magnetic resonance (MR) and 3D ultrasound (US) data. Such an atlas will benefit from the complementary motion features derived from the two modalities, and furthermore, it could be applied in clinics to detect cardiovascular disease using US data alone. The processing pipeline for the formation of the multimodal motion atlas initially involves spatial and temporal normalisation of subjects' cardiac geometry and motion. This step was accomplished following a similar pipeline to that proposed for single modality atlas formation. The main novelty of this paper lies in the use of a multi-view algorithm to simultaneously reduce the dimensionality of both the MR and US derived motion data in order to find a common space between both modalities to model their variability. Three different dimensionality reduction algorithms were investigated: principal component analysis, canonical correlation analysis and partial least squares regression (PLS). A leave-one-out cross validation on a multimodal data set of 50 volunteers was employed to quantify the accuracy of the three algorithms. Results show that PLS resulted in the lowest errors, with a reconstruction error of less than 2.3 mm for MR-derived motion data, and less than 2.5  mm for US-derived motion data. In addition, 1000 subjects from the UK Biobank database were used to build a large scale monomodal data set for a systematic validation of the proposed algorithms. Our results demonstrate the feasibility of using US data alone to analyse cardiac function based on a multimodal motion atlas.

Is Right Ventricular Remodeling in Pulmonary Hypertension Dependent on Etiology? An Echocardiographic Study.

AIMS: Survival in patients (pts) with pulmonary hypertension (PH) differs between subgroups at similar levels of pressure overload. We set to analyze right ventricular (RV) morphology and function in different types of PH using conventional and deformation imaging echocardiography. MATERIAL AND METHODS: Thirty-four pts with PH: 12 pts with idiopathic pulmonary arterial hypertension (IPAH, 42.2 ± 13 years), 11 pts with chronic thromboembolic PH (CTEPH, 50.8 ± 12 years), 11 pts with Eisenmenger syndrome [ES 41.2 ± 15 years, 4 with atrial septal defect (ASD) and 7 with ventricular septal defect (VSD)], and 13 age-matched healthy individuals (38.1 ± 15 years) were evaluated. The following echocardiographic parameters were measured: echo-derived systolic pulmonary pressure (sPAPecho), RV end-diastolic diameter (RVEDD), RV wall thickness (RVWT), TAPSE, RV fractional area change (RVFAC), Tei index, peak systolic velocity of the tricuspid ring (S't), and speckle tracking-derived RV free wall strain. Furthermore, right heart catheterization (RHC) was performed in pts with PH and mean, and systolic pulmonary artery pressure (mPAPcath, sPAPcath), cardiac output (CO), cardiac index (COi), and pulmonary vascular resistance (PVR) were noted. RESULTS: The levels of mPAPcath and sPAPcath were similar between pts with PH (pANOVA = NS). Patients with ES had higher COi compared to other groups (2.94 ± 0.79, 2.28 ± 0.69, and 1.74 ± 0.46 L/min/m(2) for pts with ES, IPAH, and CTEPH respectively, pANOVA = 0.004, P post hoc ES versus all other groups < 0.05). TAPSE, Tei index, and S't were similar between groups and impaired versus controls (pANOVA < 0.001, P post hoc between groups of patients = NS). Patients with ES had better RVFAC (41.1 ± 9, 30.5 ± 10.8, 23.2 ± 9.8%) and RV free wall strain (-20.6 ± 3.5, -16.3 ± 7.5, -10.8 ± 5%), as well as an increased thickness of the RV free wall compared to other groups of patients (9.2 ± 1.5, 7.2 ± 1 and 7.2 ± 1.6 mm for pts with ES, IPAH and CTEPH, respectively) (pANOVA<0.001, P post hoc <0.05 ES versus all other groups). RVFAC and RV free wall strain significantly correlated with COi (r = 0.53, P = 0.006 and r = -0.77, P < 0.001, respectively). CONCLUSION: Patients with ES have a more hypertrophied RV free wall, better RV performance as assessed by RVFAC and RV free wall strain and increased COi compared to other types of PH. Furthermore, RV performance appears to be less dependent on the level of pressure overload. These findings could contribute to the better survival profile of patients with ES.

Prognostic Impact of Hypertrabeculation and Noncompaction Phenotype in Dilated Cardiomyopathy: A CMR Study.

OBJECTIVES: The purpose of this study was to evaluate the impact of hypertrabeculation and left ventricular (LV) myocardial noncompaction phenotype by cardiac magnetic resonance (CMR) on outcomes of patients with nonischemic dilated cardiomyopathy (DCM). BACKGROUND: Myocardial trabeculations and noncompaction are increasingly observed in patients with DCM, but their prognostic impact remains unknown. METHODS: We prospectively evaluated outcomes of 162 consecutive patients (102 men; age 55 ± 15 years; ejection fraction [EF] 25 ± 8%) with DCM undergoing CMR. The amount of noncompaction was quantified as noncompacted/compacted (NC/C) length in the long-axis view and as the ratio of NC/C mass in the short-axis view and compared against 48 healthy control subjects (age 60 ± 10 years). RESULTS: Fifty-eight DCM patients (36%) had NC/C length ≥2.3, and 71 (44%) had NC/C mass greater than the 95% confidence interval (CI) of control subjects. NC/C length and NC/C mass did not correlate with any clinical, echocardiographic, or CMR parameters. Over a 3.4-year median follow-up, 29 patients experienced major adverse cardiovascular events (MACE) (12 cardiovascular deaths, 8 heart transplantations, 4 LV assist device implantations, and 5 resuscitated cardiac arrests or appropriate device shocks). Cox univariate analysis identified smoking, New York Heart Association functional class, blood pressure, LV and right ventricular end-diastolic and end-systolic volumes, LV EF, right ventricular EF, and late gadolinium enhancement as predictors of MACE. In multivariate analysis, only LV EF and late gadolinium enhancement were independent predictors of MACE-free survival (hazard ratio: 0.922, 95% CI: 0.878 to 0.967, p = 0.001 and HR: 1.096, 95% CI: 1.004 to 1.197, p = 0.04, respectively). Neither NC/C length nor NC/C mass had significant predictive value for MACE-free survival, either unadjusted or after adjustment for baseline variables. Also, there was no difference in cardioembolic event rate between groups with high and low NC/C length or mass. CONCLUSIONS: Cardiovascular outcomes of adult patients with nonischemic DCM do not appear to be influenced by the degree of trabeculation. This argues against a noncompaction phenotype designating a more severe form of DCM.

Does two-dimensional image reconstruction from three-dimensional full volume echocardiography improve the assessment of left ventricular morphology and function?

AIMS: (i) To investigate geometric differences between apical views of the left ventricle (LV) derived from standard 2D echocardiography (std2D) and triplane (TP) views, as well as the "ideally" reconstructed 2D (rec2D) views derived from 3D full volume (3DFV) acquisitions, and their influence on the assessment of LV morphology and function. (ii) To determine the feasibility and accuracy of the automatic reconstruction of 2D apical views from 3DFV datasets. METHODS AND RESULTS: In 59 patients with structurally normal, dilated, and hypertrophic hearts, rec2D was reconstructed manually and automatically and compared to std2D, TP, and 3DFV regarding the image plane orientation (true vs. ideal probe position, plane intersection angles), LV dimensions, volumes, and EF. The ideal probe position deviated from the true one by 6.9 ± 4.1 mm and 9.5 ± 4.5 mm, for manually and automatically rec2D, respectively, regardless of LV geometry. The mean difference ± SD between manual and automatic reconstruction was -2.5 ± 4.4 mm. LV long axis was measured minimally, but significantly longer in rec2D than std2D and TP. LV volumes and EF did not differ between methods. The intersection angle of the two-chamber view and the three-chamber view with the four-chamber view for manual and automatic reconstruction was 53° ± 7° and 129° ± 7° and 60° and 130°, respectively. CONCLUSION: Ideal reconstruction of nonforeshortened 2D images from 3DFV does not lead to a relevant improvement in image geometry or the assessment of LV morphology and function. The automatic reconstruction algorithm deviates only slightly from manual results.

How to optimize intracardiac blood flow tracking by echocardiographic particle image velocimetry? Exploring the influence of data acquisition using computer-generated data sets.

AIMS: Echocardiographic particle image velocimetry (EPIV) has been used for tracking contrast-enhanced intracavitary blood flow. Little is known, however, how basic imaging parameters (line density, frame rate, contrast bubble density) affect the quality of such tracking results. Our study aimed at investigating this by using simulated echo data sets. METHODS AND RESULTS: A computational three-dimensional (3D) blood flow field of the left ventricle (LV) was built using Fluent 12.1 (ANSYS Inc., USA). Then, the 3D motion of contrast microbubbles was simulated and 2D B-mode image loops were obtained (f = 4.5 MHz; 50 sector angle) and analysed using flow tracking software (Omega Flow, Siemens, USA). Vorticity and the resulting in-plane velocity vector field was calculated at different frame rates (227, 113, 76, and 57 fps) and bubble densities (100, 63, 36, 19, 10, and 3 bubbles/mL) and compared with the ground truth known from the computational LV flow model. The normal distribution of the amplitude error and angle error histograms confirmed the overall good performance of the tracking method. In the standard deviation analysis of error histograms, tracked velocity amplitudes correlated best with the ground truth at 10 bubbles/mL and 227 fps (45.81 ± 3.43%, P < 0.05), while the best performance of flow direction estimates was at 10 bubbles/mL and 76 fps (25.41 ± 1.22°, P < 0.05). The correlation of estimated and true vorticity tended to grow with increasing frame rate and was optimal at 19 bubbles/mL and 113 fps (r = 0.79 ± 0.02). CONCLUSION: To achieve accurate vorticity measurements, frame rate acquisitions as 113 fps and contrast bubble density of 19 bubbles/mL are needed.

Different patterns of adaptation of the right ventricle to pressure overload: a comparison between pulmonary hypertension and pulmonary stenosis.

BACKGROUND: The study was designed to compare RV morphological and functional parameters derived from conventional and myocardial deformation echocardiography in two instances of right heart pressure overload: pulmonary arterial hypertension (PAH) and pulmonary stenosis (PS). METHODS: Sixty-two individuals were included: 22 patients with pulmonary arterial hypertension (PAH), 19 patients with PS and 21 healthy individuals who served as a control group. All patients had clinical evaluation with 6-minute walking test, standard and two-dimensional strain echocardiography and B-type natriuretic peptide evaluation. RESULTS: At similar levels of pressure overload (RV systolic pressure, 88.2 ± 31.5 vs 73.4 ± 34.9 mm Hg; P = NS) the right ventricles of patients with PS were less dilated (RV end-diastolic diameter, 31.7 ± 3.7 vs 43.7 ± 10.5 mm; P < .001) and performed significantly better than those of patients with PAH (RV strain, -27.4 ± 5.8% vs 16.2 ± 7.9%; RV fractional area change, 51.1 ± 9.2% vs 29.1 ± 11.3%; P < .001). Although some of the RV functional parameters were comparable with those in healthy individuals, strain rate showed lower values, suggesting subclinical longitudinal dysfunction in patients with PS. Myocardial stress biomarkers were correlated with RV systolic pressure only in patients with PAH (r = 0.64, P = .03), not in those with PS (r = 0.22, P = .50). CONCLUSIONS: At similar levels of pressure overload, the right ventricle is less dilated and performs better in patients with PS compared with those with PAH.